Association Between Aldosterone and Hypertension Among Patients With Overt and Subclinical Hypercortisolism

Posted on December 20, 2022 by MaryO

Abstract

Introduction

Hypertension is one of the most common clinical features of patients with overt and subclinical hypercortisolism. Although previous studies have shown the coexistence of autonomous cortisol and aldosterone secretion, it is unclear whether aldosterone plays a role in hypertension among patients with hypercortisolism. Therefore, we examined the associations of plasma aldosterone concentrations (PACs) with hypertension among patients with overt and subclinical hypercortisolism.

Methods

This single-center retrospective cohort study included patients with adrenal tumor and serum cortisol levels after 1-mg dexamethasone suppression test >1.8 µg/dL (50 nmol/L). Using multivariable regression models adjusting for baseline characteristics, we investigated the association of PACs with systolic blood pressure and postoperative improvement of hypertension after the adrenalectomy.

Results

Among 89 patients enrolled in this study (median age, 51 years), 21 showed clinical signs of Cushing syndrome (overt hypercortisolism) and 68 did not show clinical presentations (subclinical hypercortisolism). We found that higher PACs were significantly associated with elevated systolic blood pressure among patients with subclinical hypercortisolism (adjusted difference [95% CI] = +0.59 [0.19-0.99], P = 0.008) but not among those with overt hypercortisolism. Among 33 patients with subclinical hypercortisolism and hypertension who underwent adrenalectomy, the postoperative improvement of hypertension was significantly associated with higher PACs at baseline (adjusted risk difference [95% CI] = +1.45% [0.35-2.55], P = 0.01).

Conclusion

These findings indicate that aldosterone may contribute to hypertension among patients with subclinical hypercortisolism. Further multi-institutional and population-based studies are required to validate our findings and examine the clinical effectiveness of the intervention targeting aldosterone for such patients.

subclinical hypercortisolism, aldosterone, hypertension, adrenalectomy

Issue Section:

Clinical Research Article

Cortisol production in the adrenal gland is regulated by the hypothalamus-pituitary-adrenal (HPA) axis. Subclinical hypercortisolism is a status characterized by the alteration of HPA axis secretion without typical signs or symptoms of overt hypercortisolism (eg, moon face, truncal obesity, easy bruising, thin extremities, proximal myopathy, cutaneous purple striae) [1, 2]. Although overt hypercortisolism can be detected by its clinical presentations or severe complications, it is sometimes challenging for clinicians to appropriately diagnose subclinical hypercortisolism because of the absence of such clinical presentations [2]. The 1-mg overnight dexamethasone suppression test (1-mg DST) measures the response of the adrenal glands to ACTH through the HPA axis and therefore has been widely used for screening and diagnosis of subclinical hypercortisolism [1, 3]. The European Society of Endocrinology Guideline has defined a partial suppression of the HPA axis (ie, serum cortisol levels after 1-mg DST [F-DST] > 1.8 µg/dL [50 nmol/L]) without clinical signs of overt cortisol hypersecretion as “possible autonomous cortisol secretion” and recommended screening these patients for metabolic disorders including hypertension and type 2 diabetes mellitus to offer appropriate treatment of these comorbidities [4].

Hypertension is one of the most common and distinguishing clinical features in patients with subclinical hypercortisolism [2] as well as overt hypercortisolism [5]. Although hypertension can be triggered by excess cortisol levels [5, 6], it is still unclear whether even slightly elevated cortisol levels among individuals with subclinical hypercortisolism contribute to the occurrence of hypertension. This raises another potential mechanism to cause hypertension such as the coexistence of hyperaldosteronism (ie, excess aldosterone that is an essential steroid hormone for sodium reabsorption, water retention, and blood pressure control) [7]. Previous studies have reported that 10% to 20% of primary aldosteronism is accompanied by cortisol-producing adenoma [8-10], and autonomous cortisol secretion was decreased after the resection of the aldosterone-producing adenoma (a subtype of primary aldosteronism) [11]. Furthermore, a previous mass spectrometry-based analysis revealed that cortisol secretion was frequently found in patients with primary aldosteronism [12]. Although these studies have examined cortisol biosynthesis in primary aldosteronism [13], evidence about whether aldosterone plays a role in the occurrence of hypertension among people with subclinical hypercortisolism is limited.

To address this knowledge gap, we performed a cohort study examining the association between aldosterone and hypertension among patients with adrenal tumor and F-DST >1.8 µg/dL, stratified by whether patients had clinical signs of Cushing syndrome or not. We first analyzed the cross-sectional association between aldosterone and blood pressure at baseline. Then, we analyzed the longitudinal association between aldosterone at baseline and the improvement rate of hypertension after the adrenalectomy. Last, to further clarify the role of aldosterone in the regulation of blood pressure in subclinical hypercortisolism, we described the difference in aldosterone response to ACTH after the adrenalectomy according to the postoperative improvement of hypertension.

Materials and Methods

Data Sources and Study Participants

A retrospective cohort study was designed to assess the clinical characteristics (focusing on aldosterone) among patients with hypercortisolism at the Yokohama Rosai Hospital from 2008 to 2017. We enrolled 89 patients with adrenal tumor and F-DST > 1.8 µg/dL (50 nmol/L) [3, 4, 14]. We then categorized them into 2 groups: (1) overt hypercortisolism (F-DST > 5.0 µg/dL [138 nmol/L]) and having clinical signs of Cushing syndrome (moon face, central obesity, dorsocervical fat pad [buffalo hump], purple striae, thin skin, easy bruising, and proximal myopathy] [15]) and (2) subclinical hypercortisolism (not having such clinical signs). All patients with overt hypercortisolism in this study showed F-DST > 5.0 µg/dL (138 nmol/L). The study was approved by the research ethics committee of the Yokohama Rosai Hospital, and all participants provided written informed consent.

Measurements

Demographic characteristics were self-reported, and body mass index (BMI) was calculated using measured weight and height. Systolic blood pressure was measured in the sitting position using a standard upper arm blood pressure monitor after a 5-minute rest in a quiet place [16]. The mean of 2 measurements was recorded. If the measurement was done only once on a given occasion, the level obtained was recorded. When the patients were already taking antihypertensives at enrollment, they were asked to report their blood pressure levels at the diagnosis of hypertension (ie, systolic blood pressure before starting antihypertensives). Blood samples were collected at 8:00 AM after the patient had rested in the supine position for 30 minutes. We measured F (µg/dL, × 27.6 for nmol/L) and ACTH (pg/mL, × 0.220 for pmol/L) using chemiluminescent enzyme immunoassay and electrochemiluminescent immunoassay, respectively. Plasma aldosterone concentrations (PACs; ng/dL, × 27.7 for pmol/L) and plasma renin activities (PRAs; ng/mL/h) were measured using radioimmunoassay. Any antihypertensive drugs were replaced with calcium channel antagonists (including dihydropyridine calcium channel antagonists) and/or α blocker several weeks before the measurement of PACs and PRAs according to the clinical guideline of the Japan Endocrine Society [17]. We also measured urine aldosterone (µg/day × 2.77 for nmol/d) and urine cortisol (µg/day, × 2.76 for nmol/d) using radioimmunoassay. The tumor size was estimated using contrast-enhanced thin-section computed tomography scans of the adrenal glands.

To evaluate whether the patients had autonomous cortisol secretion, we performed 1-mg DST, in which dexamethasone (1 mg) was administered at 11:00 PM, and blood samples were drawn at 8:00 AM the following morning. F and ACTH were measured in 1-mg DST.

The total or partial adrenalectomy was performed in all cases with overt hypercortisolism. For patients with subclinical hypercortisolism, the adrenalectomy was recommended to those who showed F-DST > 5.0 µg/dL (138 nmol/L) accompanying metabolic disorders [3]. It was also recommended to those who were expected to improve their clinical symptoms and/or metabolic disorders by the tumor resection, which included patients with hypertension possibly resulting from autonomous aldosterone secretion as well as autonomous cortisol secretion from the adrenal gland. The adrenalectomy was conducted when patients agreed with the treatment plan through informed consent. To evaluate whether patients had autonomous aldosterone secretion, we used the screening criterion of primary aldosteronism (ie, PAC/PRA ratio; aldosterone-to-renin ratio [ARR] > 20), followed by the confirmatory tests of primary aldosteronism that included the saline infusion test, captopril challenge, and/or furosemide stimulation test [17].

For patients who were considered to receive a benefit by the adrenalectomy and who agreed with the examination, we performed the segment-selective adrenal venous sampling to assess the laterality of hyperaldosteronism [18-20]. First, blood samples were collected from the bilateral central adrenal veins before ACTH stimulation. Then, we collected samples from the superior, lateral, and inferior tributaries of the right central adrenal vein and the superior and lateral tributaries of the left central adrenal vein after ACTH stimulation. Aldosterone excess (ie, hyperaldosteronism) was considered when the effluent aldosterone concentrations were > 250 ng/dL before ACTH stimulation and 1400 ng/dL after ACTH stimulation, respectively [18-20]. We used the absolute value instead of the lateralization index because individuals included in our study had elevated cortisol concentrations given the inclusion criteria (ie, F-DST >1.8 µg/dL [50 nmol/L]). For 9 patients with subclinical hypercortisolism who showed bilateral adrenal nodules, the side of adrenalectomy was determined by the nodule size and the results of adrenal venous sampling (ie, laterality of hyperaldosteronism). The adrenalectomy was conducted when patients agreed with the treatment plan through informed consent. Immunohistochemical evaluation of aldosterone synthase cytochrome P450 (CYP11B2) was conducted for some resected nodules.

To evaluate the postoperative cortisol responsiveness to ACTH, we performed an ACTH stimulation test a year after the adrenalectomy, in which blood samples were collected and PAC and F were measured 30 and 60 minutes after ACTH administration. Postoperative improvement of hypertension was defined as blood pressure <140/90 mmHg without antihypertensives or the reduction of the number of antihypertensives to maintain blood pressure <140/90 mmHg after the adrenalectomy.

Statistical Analyses

We describe the demographic characteristics and endocrine parameters at baseline comparing patients with overt hypercortisolism and those with subclinical hypercortisolism using the Fisher exact test for categorical variables and Mann-Whitney U test for continuous variables. Second, for each group, we investigated the association between the baseline characteristics and systolic blood pressure using ordinary least-squares regression models. The model included age, sex, BMI, serum potassium levels, estimated glomerular filtration rate, tumor size, and F and PAC at 8:00 AM. Third, we estimated the risk difference and 95% CI of the improvement rate of hypertension after the adrenalectomy according to these baseline characteristics (including systolic blood pressure) using a modified least-squares regression model with a Huber-White robust standard error [21]. Last, to evaluate whether the improvement of hypertension is related to postoperative cortisol and aldosterone secretion, we compared PAC and F responsiveness to ACTH from peripheral blood samples between patients who improved hypertension and those who did not using the Mann-Whitney U test. The longitudinal and postoperative analyses were performed among patients with subclinical hypercortisolism because only 2 cases with overt hypercortisolism failed to show the improvement of hypertension after the adrenalectomy.

To assess the robustness of our findings, we conducted the following 2 sensitivity analyses. First, we replaced F at 8:00 AM with F after DST in our regression models. Second, we estimated the risk difference of the improvement rate of hypertension after the adrenalectomy according to the postoperative F and PAC levels after ACTH stimulation, adjusting for the baseline characteristics included in our main model.

We also conducted several additional analyses. First, to investigate the relationship of change in PAC after adrenalectomy with the improvement rate of hypertension, we included decrease in PAC between before and after adrenalectomy instead of PAC at baseline in the model. Second, to assess the relationship between aldosterone and hypertension among patients with subclinical hypercortisolism without primary aldosteronism, we reran the analyses excluding patients who met the diagnostic criteria of primary aldosteronism. Third, to understand the overall association, we reran the analyses using all samples as a single group to assess the relationship among people with overall (ie, overt and subclinical) hypercortisolism. Last, we compared PAC and F responsiveness with ACTH during adrenal venous sampling between patients with and without postoperative improvement of hypertension. All statistical analyses were performed using Stata, version 15.

Results

Among the 89 enrolled patients, 21 showed clinical signs of overt Cushing syndrome and 68 did not. The flow of the study population is shown in Fig. 1. Among 21 patients with overt hypercortisolism, 19 patients had hypertension. All patients underwent adrenalectomy, and 16 patients showed improved hypertension levels after the surgery (1 patient was referred to another hospital; therefore, no information is available). Among 68 patients with subclinical hypercortisolism, 63 had hypertension. After the evaluation of autonomous aldosterone secretion as well as autonomous cortisol secretion, of 33 patients who underwent adrenalectomy, 23 (70%) showed improved hypertension levels after the adrenalectomy (10 patients in the surgery group decided not to undergo adrenalectomy). Patients with subclinical hypercortisolism who underwent adrenalectomy showed lower PRA and higher ARR than those without adrenalectomy (Supplementary Table S1) [22].

Figure 1.

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Enrollment and follow-up of the study population after the adrenalectomy. ^aThe prevalence of patients with overt hypercortisolism and hypertension among this study population may be higher than in the general population and therefore needs to be carefully interpreted given that the study institute is one of the largest centers for adrenal diseases in Japan. ^bAll patients in this category showed autonomous cortisol secretion (ie, serum cortisol levels >5.0 µg/dL [138 nmol/L] after a 1-mg dexamethasone suppression test). ^cOne case underwent adrenalectomy at another hospital and therefore no information was available after the adrenalectomy. ^dThe adrenalectomy was performed for 33 patients who were expected to improve their clinical symptoms and/or metabolic disorders, including hypertension. This assessment was mainly based on autonomous cortisol secretion evaluated by a 1-mg dexamethasone suppression test, complicated metabolic disorders, and autonomous aldosterone secretion evaluated by adrenal venous sampling for patients who were positive for the screening and confirmatory tests of primary aldosteronism. Details in the assessment can be found in the Methods section or elsewhere [18-20].

Demographic Characteristics and Endocrine Parameters Among Patients With Overt and Subclinical Hypercortisolism

The median age (interquartile range) was 51 years (46, 62 years), and 72% were female. Patients with overt hypercortisolism were relatively younger and showed a higher estimated glomerular filtration rate and larger tumor size compared with patients with subclinical hypercortisolism (Table 1). Other demographic characteristics were similar between these groups. Patients with overt hypercortisolism showed higher F with undetected low ACTH, higher F after DST, and higher urine cortisol levels compared with those with subclinical hypercortisolism who instead showed higher PAC and ARR. Among patients with subclinical hypercortisolism, 9/68 (13.2%) showed undetectable ACTH levels and 25/68 (36%) were positive for PA screening criterion (ie, ARR > 20) followed by at least 1 positive confirmatory test. Based on the results of adrenal venous sampling of these cases, 9 showed aldosterone excess in the right nodules, 6 showed aldosterone excess in the left nodules, and 7 showed aldosterone excess on both sides, respectively (3 cases did not show aldosterone excess on both sides). Immunohistochemical evaluation of CYP11B2 was examined for 6 resected adrenal glands, and all of them showed positive expression.

Patients’ characteristics^a	Patients with overt hypercortisolism (N = 21)	Patients with subclinical hypercortisolism (N = 68)	P
Age, y	46 [38-52]	54 [47-63]	0.002
Female, n (%)	18 (85.7)	46 (67.7)	0.11
Body mass index, kg/m²	23.4 [20.6-26.2]	23.1 [21.7-25.1]	0.94
Systolic blood pressure, mm Hg	156 [140-182]	162 [151-191]	0.29
Diastolic blood pressure, mm Hg	98 [92-110]	100 [90-110]	0.73
Serum potassium, mEq/L^b	3.9 [3.5-4.0]	3.8 [3.6-4.0]	0.98
eGFR, mL/min/1.73 m²	86.7 [77.3-123.0]	82.1 [69.8-87.7]	0.02
Tumor size by CT scan, mm	28 [25-30]	22 [17-26]	0.001
ACTH, 8:00 AM	− ^c	6.6 [2.4-11.8]	—
F, 8:00 AM	16.6 [12.5-18.8]	9.5 [7.7-12.0]	<0.001
PRA, 8:00 AM	0.7 [0.4-1.3]	0.5 [0.2-1.0]	0.10
PAC, 8:00 AM	8.3 [7.2-9.8]	9.2 [7.2-16.2]	0.09
ARR, 8:00 AM	10.0 [6.4-16.7]	21.0 [9.8-46.5]	0.02
F after DST	16.5 [14.4-18.7]	5.1 [3.2-7.5]	<0.001
Urine cortisol	220.0 [105.0-368.0]	49.5 [37.4-78.5]	<0.001
Urine aldosterone	5.7 [3.9-10.1]	7.2 [4.8-13.1]	0.16

Conversion to SI units: ACTH, pg/mL × 0.220 for pmol; F, µg/dL × 27.6 for nmol/L; PAC, ng/dL × 27.7 for pmol/L; urine aldosterone, μg/day × 2.77 for nmol/d; Urine cortisol, μg/day × 2.76 for nmol/d.

Abbreviations: ARR, aldosterone-to-renin ratio; CRH, corticotropin-releasing hormone; CT, thin-section computed tomography; DST, 1-mg dexamethasone suppression test; eGFR, estimated glomerular filtration rate; F, serum cortisol; PRA, plasma renin activity; PAC, plasma aldosterone concentration.

aData are presented as median (interquartile range) or count (proportions) unless otherwise indicated.

bSerum potassium levels were controlled using potassium supplement/tablets at enrollment.

cUndetected in all cases.

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Association of Demographic Characteristics and Endocrine Parameters With Systolic Blood Pressure

Among patients with overt hypercortisolism, we did not find a significant association of demographic characteristics and endocrine parameters with systolic blood pressure (Table 2). However, among patients with subclinical hypercortisolism, we found that higher PACs at 8:00 AM were significantly associated with systolic blood pressure (adjusted coefficient [95% CI] = +0.59 [0.19-0.99], P = 0.008). The results did not change when we used F after DST instead of F at 8:00 AM (Supplementary Table S2) [22].

Table 2.

Cross-sectional association of demographic characteristics and endocrine parameters with systolic blood pressure among patients with overt and subclinical hypercortisolism

Outcome	Systolic blood pressure at baseline
Groups	Patients with overt hypercortisolism		Patients with subclinical hypercortisolism
Parameters	Adjusted coefficient (95% CI)	P	Adjusted coefficient (95% CI)	P
Age, y	+1.73 (0.17-3.30)	0.03	+0.49 (−0.13 to 1.10)	0.12
Female	−7.48 (−76.75 to 61.79)	0.81	+15.38 (−0.83 to 31.59)	0.06
Body mass index	+5.47 (−2.4 to 13.33)	0.15	+1.07 (−0.49 to 2.63)	0.17
Serum potassium	+11.29 (−23.42 to 45.99)	0.48	−9.61 (−26.38 to 7.15)	0.26
eGFR	−0.12 (−1.00 to 0.77)	0.77	−0.44 (−0.89 to 0.01)	0.06
Tumor size	−2.39 (−6.92 to 2.14)	0.26	+0.40 (−0.46 to 1.26)	0.35
F, 8:00 AM^a,b	+1.96 (−1.27 to 5.18)	0.20	+1.26 (−1.00 to 3.52)	0.27
PAC, 8:00 AM^a	−2.86 (−7.38 to 1.66)	0.18	+0.59 (0.19-0.99)	0.008

Abbreviations: DST, 1-mg dexamethasone suppression test; eGFR, estimated glomerular filtration rate; F, serum cortisol; PRA, plasma renin activity; PAC, plasma aldosterone concentration.

aACTH and PRA were not included in the main model because they have strong correlation with F and PAC, respectively (ie, multicollinearity). The results did not change when additionally adjusting for ACTH and PRA.

bThe results did not change when we replaced F at 8:00 AM with F after DST (Supplementary Table S2).

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Association of Demographic Characteristics and Endocrine Parameters With Hypertension Improvement After the Adrenalectomy Among Patients With Subclinical Hypercortisolism

Among 33 patients with subclinical hypercortisolism and hypertension who underwent the adrenalectomy, we found that age and higher PAC were significantly associated with a higher improvement rate of hypertension after the adrenalectomy (age, adjusted risk difference [95% CI] = +2.36% [1.08-3.64], P = 0.001; PAC, adjusted risk difference [95% CI] = +1.45% [0.35-2.55], P = 0.01; Table 3). The results did not change when we used F after DST instead of F at 8:00 AM (Supplementary Table S3) [22]. Patients with improved hypertension after the surgery showed significantly lower PACs 60 minutes after a postoperative ACTH stimulation test than those without the improvement of hypertension (P = 0.05), although F and PAC/F ratio were not significantly different between these 2 groups (Table 4). The association between lower PACs after postoperative ACTH stimulation and higher improvement rate of hypertension was also found in the multivariable regression analysis adjusting for baseline characteristics (adjusted risk difference [95% CI] = −1.08% [−1.92 to −0.25], P = 0.01; Supplementary Table S4) [22].

Table 3.

Longitudinal association of demographic characteristics and endocrine parameters with hypertension improvement after the adrenalectomy among patients with subclinical hypercortisolism^a

Outcome	Hypertension improvement after the adrenalectomy
Parameters	Adjusted risk difference (95% CI)	P
Age	+2.36% (1.08-3.64)	0.001
Sex (female)	−11.32% (−61.37 to 38.73)	0.64
Body mass index	−5.08% (−10.29 to 0.13)	0.06
Systolic blood pressure	−0.67% (−1.77 to 0.43)	0.22
Serum potassium	−0.06% (−31.84 to 31.71)	1.00
eGFR	+0.53% (−0.36 to 1.42)	0.23
Tumor size	+0.79% (−1.35 to 2.93)	0.45
F, 8:00 AM^b,c	−2.81% (−7.43 to 1.81)	0.22
PAC, 8:00 AM^b	+1.45% (0.35-2.55)	0.01

Abbreviations: eGFR, estimated glomerular filtration rate; F, serum cortisol; PRA, plasma renin activity; PAC, plasma aldosterone concentration.

aAnalysis was not performed for patients with overt hypercortisolism because only 2/18 cases failed to show improved hypertension after the adrenalectomy.

bACTH and PRA were not included in the main model because they have strong correlation with F and PAC, respectively (ie, multicollinearity). The results did not change when additionally adjusting for ACTH and PRA.

cThe results did not change when we replaced F at 8:00 AM with F after DST (Supplementary Table S3).

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Table 4.

Aldosterone and cortisol response to ACTH a year after the adrenalectomy according to hypertension improvement status among patients with subclinical hypercortisolism^a

Outcome: hypertension improvement status after the adrenalectomy	Improvement (+) (N = 23)	Improvement (−) (N = 10)
Parameters	Median [IQR]	Median [IQR]	P
PAC 60 min after ACTH stimulation	13.6 [10.0-16.7]	15.5 [13.7-43.1]	0.05^b
F 60 min after ACTH stimulation	16.9 [13.7-20.6]	18.5 [13.5-24.7]	0.61
PAC/F ratio 60 min after ACTH stimulation	0.70 [0.52-1.39]	1.27 [0.50-5.44]	0.26

Conversion to SI units: F, µg/dL × 27.6 for nmol/L; PAC, ng/dL × 27.7 for pmol/L.

Abbreviations: F, serum cortisol; PAC, plasma aldosterone concentration.

aAnalysis was not performed for patients with overt hypercortisolism because only 2/18 cases failed to show improved hypertension after the adrenalectomy.

bThe association was also observed after adjusting for baseline characteristics (eg, age, sex, body mass index, systolic blood pressure, serum potassium, estimated glomerular filtration rate, tumor size) and F 60 min after ACTH stimulation a year after the adrenalectomy (Supplementary Table S4).

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Additional Analyses

Decreased PAC between before and after adrenalectomy was significantly associated with hypertension improvement (Supplementary Table S5) [22]. When we restricted samples to those without primary aldosteronism, PACs at baseline tended to be associated with systolic blood pressure but the 95% CI included the null (Supplementary Table S6) [22]. Decreased PAC after adrenalectomy was associated with hypertension improvement after the adrenalectomy, whereas PAC at baseline was not associated with that outcome (Supplementary Table S7) [22]. When we analyzed the entire sample (ie, both overt and subclinical hypercortisolism), PAC at baseline was associated with systolic blood pressure at baseline (Supplementary Table S8) [22] and hypertension improvement after the adrenalectomy (Supplementary Table S9) [22]. We also found the higher median value of PAC response to ACTH during adrenal venous sampling at the remained (ie, not resected by the adrenalectomy) side of adrenal gland among patients whose hypertension did not improve compared with those whose hypertension improved after the surgery, but the difference was not statistically significant (Supplementary Table S10) [22].

Discussion

In this retrospective cohort study, we found that higher aldosterone levels were associated with higher systolic blood pressure among patients with possible autonomous cortisol secretion and without clinical signs of overt Cushing syndrome (ie, subclinical hypercortisolism). In this group, higher aldosterone before the adrenalectomy was associated with the postoperative improvement of hypertension. Moreover, we found that patients with postoperative improvement of hypertension showed lower aldosterone response to ACTH after the adrenalectomy compared with those without the improvement of hypertension. Decrease in PACs after the adrenalectomy was associated with improved hypertension even among patients with subclinical hypercortisolism who did not have primary aldosteronism at baseline, whereas baseline PAC was not associated with that outcome. We found no evidence that aldosterone is associated with systolic blood pressure among patients with overt hypercortisolism. These findings indicate that elevated aldosterone may contribute to the presence of hypertension and its improvement rate after the adrenalectomy for patients with subclinical hypercortisolism.

To the best of our knowledge, this is one of the first studies to assess the potential role of aldosterone in hypertension among patients with overt and subclinical hypercortisolism, during both pre- and postoperative phases. Since aldosterone- and cortisol-producing adenoma was reported in 1979 [23, 24], several studies have assessed the cortisol production in aldosterone-producing adenoma clinically and histologically [8-10, 25] and showed the correlation between the degree of glucocorticoid excess levels and metabolic markers including BMI, waist circumference, blood pressure, insulin resistance, and high-density lipoprotein [12]. Prior research suggested that aldosterone-producing adenoma might produce cortisol as well as aldosterone even when serum cortisol levels after DST is less than 1.8 µg/dL (50 nmol/L) [11]. Although these studies have focused on cortisol synthesis among patients with aldosterone-producing adenoma, little is known about aldosterone synthesis among patients with cortisol-producing adenoma. Given that patients with hypercortisolism tend to have therapy-resistant hypertension and electrolyte disorders [8], our findings may generate the hypothesis that aldosterone contributes to the incidence and severity of hypertension in patients with possible autonomous cortisol secretion; this warrants further investigation.

There are several mechanisms by which cortisol excess leads to hypertension, such as regulating endothelial nitric oxide synthase expression modulated by 11β-hydroxysteroid dehydrogenases [26], activating the mineralocorticoid receptor [27] and upregulating vascular endothelin-1 [28]. Moreover, hypercortisolism impairs the production of endothelial vasodilators, including prostacyclin, prostaglandins, and kallikreins [29]. Despite these potential mechanisms, the direct effect of cortisol may not be sufficient to explain hypertension in patients with hypercortisolism, particularly subclinical hypercortisolism, and the presence of cortisol and aldosterone coproducing adenoma indicates another potential pathway to induce hypertension through aldosterone excess. Aldosterone is a steroid hormone not only promoting sodium reabsorption and volume expansion but also activating the mineralocorticoid receptor in the kidney and nonepithelial tissues (eg, adipose tissue, heart, endothelial cells, and vascular smooth muscle cells) [30]. It also induces oxidative stress, inflammation, fibrosis, vascular tone, and endothelial dysfunction [31]; therefore, aldosterone excess could induce hypertension even when it is slightly elevated [32]. A recent multiethnic study showed that aldosterone levels within the reference range were associated with subclinical atherosclerosis partially mediated through elevated blood pressure [33]. These mechanisms support our results indicating the potential contribution of aldosterone to hypertension among patients with subclinical hypercortisolism.

This study had several limitations. First, we did not have information on the duration of cortisol excess and therefore the estimated effect of cortisol on hypertension in our study might have been underestimated. The duration of exposure to mild hypercortisolism may be one of the important drivers of cardiovascular and metabolic disorders including irreversible vasculature remodeling in patients with subclinical hypercortisolism [2]. Second, we did not have the genetic information of adrenal tumors including aldosterone-producing adenoma. Given the heterogeneity of aldosterone responsiveness to ACTH [34] and postoperative hypertension resolution rate across genetic mutations (eg, KCNJ5, ATP1A1, ATP2B3, CACNA1D, CTNNB1) [35], such information might affect our findings. Third, because of the nature of an observational study, we cannot rule out the unmeasured confounding. Fourth, because aldosterone and cortisol levels were measured at a single point, we may have a risk of mismeasurement. Moreover, when evaluating aldosterone levels, we used dihydropyridine calcium channel blockers to control hypertension based on the clinical guideline of primary aldosteronism in Japan; this might lower serum aldosterone levels. Fifth, because the present study was conducted at a single center, selection bias is inevitable [13]. Given that primary aldosteronism—one of the major causes of secondary hypertension—has still been underdiagnosed, partially because of insufficient recognition of clinical guidelines [36], our findings may indicate the importance of considering aldosterone when evaluating patients with subclinical hypercortisolism accompanied by hypertension. However, we need to carefully interpret the observed “prevalence” in this study because individuals potentially having subclinical hypercortisolism were likely to come to our hospital, which specializes the adrenal disorders, and thus the numbers do not reflect the prevalence in general population. The small number of resected adrenal glands with the evaluation of CYP11B2 expression in this study cohort also limits the prevalence estimation of primary aldosteronism. Finally, as we only followed up 1 year after the adrenalectomy, we could not evaluate the long-term resolution rate of hypertension. To overcome these limitations and generalize our findings, future molecular studies and multicenter longitudinal studies with sufficient individual datasets and longer follow-up are required.

In conclusion, plasma aldosterone concentrations were associated with systolic blood pressure and improvement rate of hypertension after the adrenalectomy among patients with subclinical hypercortisolism—possible autonomous cortisol secretion without clinical signs of overt Cushing syndrome. Our findings underscore the importance of considering aldosterone when patients have an adrenal tumor with possible autonomous cortisol secretion complicated with hypertension. Future molecular and epidemiological studies are warranted to identify the potential role of aldosterone in hypertension among patients with subclinical hypercortisolism, clarify how often these patients also have primary aldosteronism, and examine the clinical effectiveness of the intervention targeting aldosterone for such patients.

Funding

K.I. was supported by the Japan Society for the Promotion of Science (JSPS; 21K20900 and 22K17392) and The Japan Endocrine Society. Study sponsors were not involved in study design, data interpretation, writing, or the decision to submit the article for publication. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Conflicts of Interest

All of authors confirm that there is no conflict of interest in relation to this work.

Data Availability

Restrictions apply to the availability of some data generated or analyzed during this study to preserve patient confidentiality or because they were used under license. The corresponding author will on request detail the restrictions and any conditions under which access to some data may be provided.

Abbreviations

ARR

aldosterone-to-renin ratio
BMI

body mass index
DST

dexamethasone suppression test
F

serum cortisol level
HPA

hypothalamus-pituitary-adrenal
PAC

plasma aldosterone concentration
PRA

plasma renin activity

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Characterization of Adrenal miRNA-Based Dysregulations in Cushing’s Syndrome

Posted on August 15, 2022 by MaryO

Abstract

MiRNAs are important epigenetic players with tissue- and disease-specific effects. In this study, our aim was to investigate the putative differential expression of miRNAs in adrenal tissues from different forms of Cushing’s syndrome (CS). For this, miRNA-based next-generation sequencing was performed in adrenal tissues taken from patients with ACTH-independent cortisol-producing adrenocortical adenomas (CPA), from patients with ACTH-dependent pituitary Cushing’s disease (CD) after bilateral adrenalectomy, and from control subjects. A confirmatory QPCR was also performed in adrenals from patients with other CS subtypes, such as primary bilateral macronodular hyperplasia and ectopic CS. Sequencing revealed significant differences in the miRNA profiles of CD and CPA. QPCR revealed the upregulated expression of miR-1247-5p in CPA and PBMAH (log2 fold change > 2.5, p < 0.05). MiR-379-5p was found to be upregulated in PBMAH and CD (log2 fold change > 1.8, p < 0.05). Analyses of miR-1247-5p and miR-379-5p expression in the adrenals of mice which had been exposed to short-term ACTH stimulation showed no influence on the adrenal miRNA expression profiles. For miRNA-specific target prediction, RNA-seq data from the adrenals of CPA, PBMAH, and control samples were analyzed with different bioinformatic platforms. The analyses revealed that both miR-1247-5p and miR-379-5p target specific genes in the WNT signaling pathway. In conclusion, this study identified distinct adrenal miRNAs as being associated with CS subtypes.

Keywords: cortisol; ACTH; miRNA; Cushing’s; hypercortisolism; pituitary

1. Introduction

Cushing’s syndrome (CS) results from the excessive secretion of cortisol, leading to visceral obesity, resistance to insulin, osteoporosis, and altered lipid and glucose metabolism [1,2]. Excessive production of cortisol by the adrenal glands can be either ACTH-dependent or -independent. In the majority of patients, hypercortisolism is due to ACTH secretion by corticotroph adenomas of the pituitary gland (Cushing’s disease, CD) or by ectopic tumors [3]. Approximately 20% of cases are ACTH-independent, where cortisol is secreted autonomously by the adrenal cortex. The pathology of ACTH-independent cases is diverse; they are most often caused by unilateral cortisol-producing adrenocortical adenomas (CPA). Rare causes are cortisol-secreting adrenocortical carcinomas (ACC), primary bilateral macronodular adrenocortical hyperplasia (PBMAH), bilateral CPAs, and primary pigmented nodular adrenal disease (PPNAD) [4,5]. Irrespective of the subtype, prolonged exposure to cortisol in CS is associated with increased mortality and cardiovascular morbidity in its patients [6]. Treatment is based on the underlying cause of hypercortisolism, with pituitary surgery or adrenalectomy being the preferred choice. Medical therapy options in CS are few and consist of pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists [7]. For the timely diagnosis and targeted management of CS and its subtypes, a comprehensive understanding of cortisol secretion, in terms of canonical signaling pathways as well as upstream epigenetic factors, is needed.

MiRNA molecules have emerged as key epigenetic players in the transcriptional regulation of cortisol production. Briefly, the deletion of Dicer in adrenals, a key miRNA processing enzyme, revealed diverse expression changes in miRNAs along with related changes in steroidogenic enzymes such as Cyp11b1 [8]. Furthermore, key enzymes in the cortisol biosynthesis pathway, namely Cyp11a1, Cyp21a1, Cyp17a1, Cyp11b1, and Cyp11b2, were also found to be regulated by various miRNAs (miRNA-24, miRNA-125a-5p, miRNA-125b-5p, and miRNA-320a-3p) in in vitro studies [9]. Consequently, various studies have also characterized miRNA expression profiles in CS subtypes. Importantly, miRNA expression in the corticotropinomas of CD patients was found to vary according to USP8 mutation status [10]. Other studies have also identified specific miRNA candidates and associated target genes in the adrenals of patients with PPNAD [11], PBMAH [12,13], and massive macronodular adrenocortical disease [14]. Interestingly, no common miRNA candidates were found among these studies, indicating the specificity of miRNAs to the different underlying pathologies in CS.

There are limited studies directly comparing miRNA expression profiles of ACTH-dependent and ACTH-independent CS patients. Consequently, in our previous study, we found differences in expression profiles when comparing circulating miRNAs in CD and CPA patients [15]. We hypothesized that the presence of ACTH possibly influences the miRNA profile in serum due to the upstream differential expression in the origin tissues. In this study, we aim to further explore this hypothesis by comparing the miRNA expression profile of adrenal tissues in ACTH-dependent and ACTH-independent CS. In brief, miRNA specific sequencing was performed in two prevalent subtypes of CS: in CD, the most prevalent ACTH-dependent form; and in CPA, the most prevalent ACTH-independent form. Specific miRNA candidates related to each subtype were further validated in other forms of CS. To further investigate our hypothesis, the response of miRNA candidates following ACTH stimulation was assessed in mice, and the expression of miRNAs in murine adrenals was subsequently investigated. Finally, an extensive targeted gene analysis was performed based on in silico predictions, RNA-seq data, and luciferase assays.

2. Results

2.1. Differentially Expressed miRNAs

NGS revealed differentially expressed miRNAs between the different groups analyzed (Figure 1). CD and CPA taken together as CS showed a differentially expressed profile (42 significant miRNAs) in comparison to controls. Moreover, individually, CPA and CD were found to show a significantly different expression profile in comparison to controls (n = 38 and n = 17 miRNAs, respectively). Interestingly, there were no significantly upregulated genes in the adrenals of patients with CD in comparison to the control adrenals. A comparative analysis of the top significant miRNAs (log2 fold change (log2 FC) > 1.25 & p < 0.005) between the two groups was performed and the representative Venn diagrams are given in Figure 2. Briefly, miR-1247-5p, miR-139-3p, and miR-503-5p were significantly upregulated in CPA, in comparison to both CD and controls. Furthermore, miR-150-5p was specifically upregulated in CPA as compared to CD. Several miRNAs (miR-486-5p, miR-551b-3p, miR-144-5p, miR-144-3p, and miR-363-3p) were found to be significantly downregulated in the groups of CPA and CD in comparison to controls. MiR-19a-3p and miR-873-5p were found to be commonly downregulated in CPA in comparison to both CD and controls. Principal component analyses based on miRNA sequencing did not identify any major clusters among the samples. Furthermore, the miRNA profile was not different among the CPA samples based on the mutation status of PRKACA (Supplementary Materials Figure S1).

Figure 1. Differentially expressed miRNAs from sequencing. Volcano plot showing the relationship between fold change (log2 fold change) and statistical significance (−log10 p value). The red points in the plot represent significantly upregulated miRNAs, while blue points represent significantly downregulated miRNAs. CPA, cortisol producing adenoma; CD, Cushing’s disease; Cushing’s syndrome represents CPA and CD, taken together.

Figure 2. Venn analyses of the common significant miRNAs from each group. The significantly expressed miRNAs from each sequencing analysis were shortlisted and compared between the groups. CPA, cortisol producing adenoma; CD, Cushing’s disease.

2.2. Validation and Selection of Candidate miRNAs

For validation by QPCR, the most significant differentially expressed miRNAs (log2 FC > 1.25 & p < 0.005) among the groups were chosen (Table S1). According to the current knowledge, upregulated miRNAs are known to contribute more to pathology than downregulated miRNAs [16]. Since the total number of significantly upregulated miRNAs was six, all these miRNAs were chosen for validation. Contrarily, 25 miRNAs were significantly downregulated among the groups. In particular, miR-486-5p, miR-551b-3p, miR-144-5p, miR-144-3p, and miR-363-3p were found to be commonly downregulated in the CS group in comparison to controls; therefore, these miRNAs were chosen for validation.

Among the upregulated miRNA candidates, miR-1247-5p QPCR expression confirmed the NGS data (Figure 3A, Table S1). Moreover, miR-150-5p and miR-139-3p were upregulated in CPA specifically in comparison to CD, and miR-379-5p was upregulated in CD in comparison to controls by QPCR. In the case of downregulated genes, none of the selected miRNAs could be confirmed by QPCR (Figure 3B). Thus, analysis of the six upregulated and five downregulated miRNAs from NGS yielded two significantly upregulated miRNA candidates, miR-1247-5p in CPA and miR-379-5p in CD, when compared to controls. These miRNA candidates were taken up for further QPCR validation in an independent cohort of other subtypes of CS (Figure 4), namely ACTH-dependent ectopic CS (n = 3) and ACTH-independent PBMAH (n = 10). The QPCR analysis in the other subtypes revealed miR-1247-5p to be consistently upregulated in ACTH-independent CS (PBMAH and CPA) in comparison to ACTH-dependent CS (CD and ectopic CS) and controls. On the other hand, miR-379-5p was upregulated in CD and PBMAH in comparison to controls.

Figure 3. QPCR analyses of significant miRNAs from sequencing analyses. Data are represented as mean ± standard deviation (SD) of −dCT values: (A) Expression analysis of significantly upregulated miRNAs; (B) Expression analysis of common significantly downregulated miRNAs. Housekeeping gene: miR-16-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

Figure 4. QPCR analyses of significantly upregulated miRNAs from validation QPCR. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: miR-16-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

2.3. In Vivo Assessment of ACTH-Independent miR-1247-5p

To analyze the influence of ACTH on miRNA expression, the expression of miR-1247-5p and miR-379-5p were assessed in the adrenal tissues of ACTH stimulated mice at different time points. For this analysis, miR-96-5p was taken as a positive control, as it has previously been reported to be differentially expressed in ACTH stimulated mice [17]. The analyses revealed that the expression of miR-1247-5p and miR-379-5p did not change at different timepoints of the ACTH stimulation (Figure 5). Meanwhile, the positive control of mir-96-5p showed a dynamic expression pattern with upregulation after 10 min, followed by downregulation at the subsequent 30 and 60 min time points, in concordance with previously reported findings [18].

Figure 5. Analysis of miRNA expression in ACTH stimulated mice tissue. QPCR analyses of positive controls, miR-96-5p, and candidates miR-379-5p and miR-1247-5p. Mice were injected with ACTH, and adrenals were collected at different timepoints to assess the impact of ACTH on miRNA expression. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: miR-26a-5p. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

2.4. In Silico Analyses of miRNA Targets

Two diverse approaches were employed for a comprehensive in silico analysis of the miRNA targets. First, the predicted targets of miR-1247-5p and miR-379-5p were taken from the TargetScan database, which identified miRNA–mRNA target pairs based on sequence analyses [19]. The expression status of these targets was then checked in the RNA sequencing data from CPA vs. controls (miR-1247-5p) and PBMAH vs. controls (miR-379-5p). Targets that showed significant expression changes in the sequencing data were shortlisted (Figure 6A). Among the 1061 predicted miR-1247-5p targets, 28 genes were found to show significant expression changes in CPA (20 upregulated, 8 downregulated). On the other hand, for 124 predicted miR-379-5p targets, 23 genes were found to show significant expression changes in PBMAH (20 upregulated, 3 downregulated). Interestingly, the selected targets were found to be unique for each miRNA, except for FICD (FIC domain protein adenylyltransferase) (Figure 6B).

Figure 6. (A) Differentially expressed target genes of miRNAs from sequencing. Data are represented as log2 fold change in comparison to the controls. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05. (B) Venn analyses of common significant miRNA target genes and related pathways. The significantly expressed targets from each sequencing analysis were shortlisted and compared between the groups. Predicted pathways of the targets from the Panther database were shortlisted and compared between the groups.

2.5. In Vitro Analyses of miR-1247-5p Targets

For in vitro analyses, we focused on downregulated targets, as we expect our upregulated miRNA candidates to cause a downregulation of the target mRNAs. For our downregulated mRNAs, only targets of miR-1247-5p were found to have published links to CS, namely Cyb5a, Gabbr2, and Gnaq (Table 1). Therefore, these three targets were then verified by QPCR in the groups of CPA, CD, PBMAH, ectopic CS, and controls (Figure 6). Only Cyb5A was found to be significantly downregulated in ACTH-dependent forms (ectopic CS and CD) as well as in ACTH-independent CS (PBMAH and CPA) in comparison to controls. Consequently, to assess whether Cyb5a is indeed regulated by miR-1247-5p, a dual luciferase assay was performed. To prove our hypothesis, treatment of Cyb5a-WT cells with miR-1247-5p mimic was expected to lead to a reduced luminescence, whereas no effects were expected in cells treated with the miR-1247-5p inhibitor or the Cyb5a-mutant (with a mutation in the miR-1247-5p binding site). As shown in Figure 7, transfection of miR-1247-5p significantly reduced luminescence from Cyb5a-WT in comparison to cells transfected with Cyb5a-WT and miR-1247-5p inhibitors. However, these predicted binding results were not found to be specific, as there were no significant differences when compared to wells transfected with Cyb5a-WT alone (Figure 8). Consecutively, when the mutated Cyb5a-Mut were transfected along with the mimics and inhibitors, no significant differences in luminescence were observed in the transfected population. Thus, direct interaction between miR-1247-5p and its predicted target gene Cyb5A could not be conclusively proven using this luciferase assay.

Figure 7. QPCR analyses of the top predicted targets of miR-1247-5p. Data are represented as mean ± standard deviation (SD) of −dCT values. Housekeeping gene: PPIA. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p-value < 0.05 (*).

Figure 8. Results of dual luminescence assay on cells transfected with miR-1247-5p mimics and related controls. Cells were transfected with plasmids containing either the WT or Mut miRNA binding sequence in Cyb5a. Either miR-1247-5p mimics or miR-1247-5p inhibitors were transfected together with the respective plasmids. Data are represented as mean ± standard error of mean (SEM) of relative luminescence unit values. Statistics: ANOVA test with Bonferroni correction to detect significant differences between patient groups with at least a significance of p value < 0.05 (*).

Table 1. Analysis of the predicted targets of miR-1247-5p and their expression levels in comparison to controls (log2 fold change). Published literature on target genes in reference to CS is highlighted in bold.

2.6. Pathway Analyses of miRNA Targets

For the pathway analysis (Reactome) we used the 28 predicted miRNA-1247-5p targets and the 23 predicted miRNA-379-5p targets from TargetScan, which were significantly differently expressed in the RNA-seq (Figure 6). Concurrently, the pathways commonly enriched by both miRNAs included the WNT signaling pathway and N-acetyl-glucosamine synthesis (Figure 9A). As a complementary approach, in silico analyses were also performed based on the targets from miRTarBase. In this database, targets are shortlisted based on published experimental results. In this analysis, miR-1247-5p (n = 21) and miR-379-5p targets (n = 85) were unique. While the validated targets of miR-379-5p were found to show significant changes in expression in the RNA-seq data from PBMAH (n = 12), none of the validated miR-1247-5p targets were found to show significant expression changes in the RNA-seq data from CPA. Therefore, all the validated targets of the miRNAs were subjected to pathway analyses (Panther). Interestingly, the WNT signaling pathway was also found to be commonly regulated by both miRNAs using this approach (Figure 9B). Finally, the expression status of target genes related to WNT signaling pathways were checked in our RNA-seq data (Figure S2). Given the upregulated status of the miRNAs, a downregulated expression of its target genes was expected. However, a significantly upregulated expression was observed for DVL1 in CPA in comparison to controls and for ROR1 in PBMAH in comparison to controls.

Figure 9. Pathway analyses of miRNA target genes. (A) The predicted targets were matched with the RNA-seq expression data. For miR-1247-5p, CPA vs. controls expression data; and for miR-379-5p, PBMAH vs. controls expression data. The significantly expressed target genes were then subjected to pathway analyses by Reactome. The significantly enriched pathway networks (p < 0.05) and their related genes are given. (B) The experimentally validated target genes from miRTarBase were analyzed for their role in pathways by the Panther database. The target genes and their related pathways are given. The commonly represented pathways are marked in bold.

3. Discussion

MiRNAs are fine regulators of both physiology and pathology and have diverse roles as diagnostic biomarkers as well as therapeutic targets. While circulating miRNAs have been investigated as potential biomarkers for hypercortisolism in CS subtypes (36), comprehensive analyses of their pathological role in CS subtypes have not yet been performed. This study hoped to uncover the pathological role of miRNAs in different CS subtypes as well as identify unique epigenetic targets contributing to hypercortisolism in these subtypes. As such, miRNA sequencing was performed in the ACTH-independent CPA and ACTH-dependent CD, with additional QPCR validation in PBMAH and ectopic CS. As expected, miRNA expression profiles in CD and CPA were very different.

3.1. ACTH-Independent Upregulated miRNAs in CS

Among the analyzed miRNAs, only miR-1247-5p and miR-379-5p showed the most prominent changes in expression levels. Briefly, miR-1247-5p was significantly upregulated in ACTH-independent forms of CS, CPA, and PBMAH (Figure 1 and Figure 3) while miR-379-5p was found to be upregulated in CD and PBMAH, in comparison to controls. Even though CD and PBMAH represent CS subtypes with different ACTH dependence, albeit both with hyperplastic tissue, it is interesting to find a shared miRNA expression status. Concurrently, miRNAs have been identified as dynamic players in regulating the acute effect of ACTH on adrenal steroidogenesis in in vivo murine studies [20,21]. Further diverse miRNAs have been characterized to regulate steroidogenesis in ACTH and dexamethasone treated rats [22] (suppressed ACTH) as well as in in vitro studies [20]. It is possible that miR-379-5p contributes to the adrenal hyperplasia present in both PBMAH and CD by targeting specific genes related to hyperplasia, and miR-1247-5p by contributing to cortisol production independent of ACTH regulation in CPA and PBMAH.

Interestingly, the miRNA candidates (mir-1247-5p and miR-379-5p) in our study have not been previously characterized in any of these studies. Furthermore, the expression of mir-1247-5p and miR-379-5p were found to be independent of ACTH stimulation, underlying their role in CS independently of the HPA axis control and postulating specific regulatory processes.

3.2. Target Genes of miRNAs in CS

Initially, we focused on the selection of known CS specific target genes that could be directly repressed by miRNAs, thereby contributing to pathology. The predicted target genes of miR-1247-5p and miR-379-5p were assessed for their downregulated expression status in the RNA-seq data. Among the selected target genes, only Cyb5a was found to be significantly downregulated in all forms of CS (Figure 6). Cytochrome b5 (CYB5A) is a marker of the zona reticularis and is an important regulator of androstenedione production [23,24]. Based on its role in adrenal steroidogenesis, it is possible that Cyb5a is downregulated by miR1247-5p. To prove our hypothesis, a dual luciferase assay was performed in HELA cell line to identify a direct interaction between Cyb5a and miR-1247-5p (Figure 7). Unfortunately, a direct interaction could not be proven, indicating that miR-1247-5p perhaps regulates its target genes in different ways.

3.3. Pathway Analyses of miRNA Targets

To identify miRNA specific regulatory processes, comprehensive target and pathway analyses were performed. Independent pathway analyses of the respective targets with two different databases of Reactome and Panther showed the WNT signaling pathway as a common targeted pathway of both mir-1247-5p and miR-379-5p (Figure 8). The WNT signaling pathway represents a crucial regulator in diverse developmental as well as pathological processes with tissue-specific effects [25,26]. Consequently, the WNT pathway has been largely characterized as one of the dysregulated pathophysiological mechanisms in CPA. Mutations in PRKACA, one of the WNT signaling proteins, are present in approximately 40% of CPA [27]. In the case of CD, dysregulated WNT signaling has been characterized as promoting proliferation in ACTH-secreting pituitary adenomas [28]. Moreover, activating mutations in beta catenin, one of the WNT signaling pathways, has been characterized as driving adrenal hyperplasia through both proliferation-dependent and -independent mechanisms [29]. Thus, it could be hypothesized that by targeting specific genes in the pathway, miRNAs drive specific pathophysiological processes in diverse CS subtypes.

3.4. MiRNA Target Genes in WNT Signaling

DVL1 (TargetScan) and DVL3 (miRTar) are the shortlisted target genes of miR-1247-5p in the WNT signaling pathway. These genes are members of canonical WNT pathways and, importantly, activation of the cytoplasmic effector Dishevelled (Dvl) is a critical step in WNT/β-catenin signaling initiation [30,31]. Interestingly, no difference in DVL1 and DVL3 gene expression was found in the analyses of ACTH-secreting pituitary adenomas [32]. Therefore, it could be possible that DVL1 and DVL3 are only targeted by miR-1247-5p specifically in the adrenal of CPA and PBMAH patients, leading to its characterized tumor progression. EDN1, TGFBR1 (TargetScan), and ROR1 (miRTar) were the target genes of miR-379-5p related to the WNT pathway. In epithelial ovarian cancer, Endothelin-1 (EDN-1) was found to regulate the epithelial–mesenchymal transition (EMT) and a chemoresistant phenotype [33]. In the case of receptor tyrosine kinase-like orphan receptor 1 (ROR1), higher expression of the gene was associated with a poor prognosis in ovarian cancer [34]. Concurrently, suppression of TGFBR1-mediated signaling by conditional knockout in mice was found to drive the pathogenesis of endometrial hyperplasia, independent of the influence of ovarian hormones [35]. Therefore, it could be hypothesized that the dysregulated expression of these factors in adrenals could trigger similar hyperplastic effects mediated by these factors, as in ovarian tissues.

3.5. Bottlenecks and Future Outlook

Interestingly, among these genes, only DVL1 and ROR1 were found to be significantly upregulated in the RNA-seq data (Figure S2). The major regulatory role of miRNAs in gene expression come from their ability to repress gene expression at the level of transcription and translation. There are also reports of miRNA-mediated gene upregulation; however, the physiological evidence of the role is still unresolved [36]. Therefore, it is interesting to see the selected targets of miR-1247-5p and miR-379-5p upregulated. Moreover, it should be noted that most of the experimentally validated miRNA targets were identified by CLIP methods [37]. Crosslinking immunoprecipitation (CLIP) are binding assays that provide genome-wide maps of potential miRNA-target gene interactions based on sequencing. Moreover, these assays do not make functional predictions on the outcome of miRNA binding, and neither do upregulation or downregulation [38,39]. Therefore, in our current experimental setting, we could only identify potential miRNA target genes and speculate on their pathological role based on the published literature and in silico analyses. Furthermore, extensive mechanistic analyses based on these potential targets could help in elaborating the specific epigenetic pathways that fine-tune CS pathology in different subtypes.

4. Materials and Methods

4.1. Sample Collection and Ethics Approval

All patients were registered in the German Cushing’s Registry, the ENS@T or/and NeoExNET databases (project number protocol code 379-10 and 152-10). The study was approved by the Ethics Committee of the University of Munich. All experiments were performed according to relevant guidelines and protocols, and written informed consent was obtained from all patients involved. The adrenal samples used in the sequencing (miRNA and RNA) belong to the same patient.

For miRNA-specific next-generation sequencing (NGS), a total of 19 adrenocortical tissue samples were used. The cohort consisted of the following patient groups: ACTH-independent CPA, n = 7; ACTH-dependent hypertrophic adrenals of CD patients after bilateral adrenalectomy, n = 8; normal adjacent adrenal tissue from patients with pheochromocytoma as controls, n = 8. For QPCR validation, the patient groups included adrenal tissue from ACTH-independent PBMAH, n = 10, and ACTH-dependent ectopic CS, n = 3.

In the case of mRNA sequencing, a total of 23 adrenocortical tissue samples were used. This includes the following patient groups: CPA, n = 7; PBMAH, n = 8; normal adjacent adrenal tissue from patients with pheochromocytoma as controls, n = 8.

The clinical characteristics of the patients are given in Table 2. Furthermore, of the eight CPA samples in the study, three of them carried known somatic driver mutations in the PRKACA gene and in the ten PBMAH samples, two carried germline mutations in the ARMC5 gene.

Table 2. Clinical characteristics of the patient groups. Data are given as median with 25th and 75th percentiles in brackets. CPA, cortisol producing adenoma; CD, Cushing’s disease.

The adrenal tissues were stored at −80 °C. Total RNA isolation was carried out from all adrenal cortex samples by an RNeasy Tissue Kit (Qiagen, Hilden, Germany). The isolated RNA was kept frozen at −80 °C until further use.

4.2. MiRNA and RNA Sequencing

RNA integrity and the absence of contaminating DNA were confirmed by Bioanalyzer RNA Nano (Agilent Technologies, Santa Clara, CA, USA) and by Qubit DNA High sensitivity kits, respectively. Sequencing libraries were prepared using the Illumina TruSeq Small RNA Library Preparation Kit. NGS was performed on 2 lanes of an Illumina HiSeq2500 (Illumina, CA, USA) multiplexing all samples (paired end read, 50 bp). The quality of sequencing reads was verified using FastQC0.11.5 (http://www.bioinformatics.babraham.ac.uk/projects/fastqc, date last accessed: 13 March 2020) before and after trimming. Adapters were trimmed using cutadapt [40]. Reads with <15 bp and >40 bp insert sequences were discarded. An alignment of reads was performed using miRBase V21 [41,42] with sRNAbench [43]. EdgeR and DeSeq in R were used for further analyses [44,45]. MiRNAs with at least 5 raw counts per library were included. RNA-seq was performed by Qiagen, Hilden, Germany. For mRNA, sequencing was performed on Illumina NextSeq (single end read, 75 bp). Adapter and quality trimming were performed by the “Trim Reads” tool from CLC Genomics Workbench. Furthermore, reads were trimmed based on quality scores. The QC reports were generated by the “QC for Sequencing Reads” tool from CLC Genomics Workbench. Read mapping and gene quantification were performed by the “RNA-seq Analysis” tool from CLC Genomics Workbench [46]. The miRNA-seq data generated in this study have been submitted to the NCBI (PRJNA847385).

4.3. Validation of Individual miRNAs

MiRNAs and genes significantly differentially expressed by NGS were validated by QPCR. Reverse transcription of miRNA-specific cDNA was performed by using the TaqMan MicroRNA Reverse Transcription Kit (Thermo Fisher Scientific, Munich, Germany), and the reverse transcription of RNA genes was done by using the Superscript VILO cDNA synthesis Kit (Thermo Fisher Scientific, Munich, Germany). 50 ng of RNA was used for each of the reverse transcription reactions. Quantitative real-time PCR was performed using the TaqMan Fast Universal PCR Master Mix (2×) (Thermo Fisher Scientific, Munich, Germany) on a Quantstudio 7 Flex Real-Time PCR System (Thermo Fisher Scientific, Munich, Germany) in accordance with the manufacturer’s protocol. All QPCR reactions were performed in a final reaction volume of 20 μL and with 1 μL of 1:5 diluted cDNA. Negative control reactions contained no cDNA templates. Gene expression was quantified using the relative quantification method by normalization with reference gene [47]. Statistical analysis using the bestkeeper tool was used to compare and select the best reference gene with stable expression across the human adrenal samples [48]. Reference genes with significantly different Ct values (p-value < 0.01) between the samples were excluded. Furthermore, primer efficiency and the associated correlation coefficient R2 of the selected reference gene were determined by the standard curve method in serially diluted cDNA samples [49]. In the case of miRNA reference genes, miR-16-5p [48,50,51] and RNU6B [52] previously used in similar studies were compared. MiR-16-5p was found to show the most stable expression levels across the samples with a p-value of 0.452 in comparison to RNU6B which had a p-value of 0.001. In the case of RNA reference genes, PPIA [53] and GAPDH [54] were compared. Here, PPIA was found to show the most stable expression levels across the samples with a p-value of 0.019 in comparison to GAPDH which had a p-value of 0.003. Therefore, these genes were used for the normalization of miRNA and RNA expression in human adrenal samples.

4.4. Target Screening

In silico prediction of the possible miRNA targets was performed using the miRNA target database, TargetScan, and miRTarBase [19,37]. The top predicted targets were further screened based on their expression status in the RNA-seq data from the adrenocortical tissues of CPA, PBMAH, and controls (unpublished data). Pathway analyses of the targets were performed using Reactome [55] and Panther [56] online platforms. The selected downregulated targets were analyzed by QPCR in the adrenocortical samples to confirm their expression status. The successfully validated candidates were then analyzed for regulation by the miRNA using a dual luciferase assay [57].

4.5. Dual Luciferase Assay

The interaction between the predicted 3′-UTR region of Cyb5a and miR-1247-5p was detected using a luciferase activity assay. The 3′UTR sequences of Cyb5a (129 bp) containing the predicted miR-1247-5p binding sites (psiCHECK-2 Cyb5a 3′UTR WT) were cloned into the psiCHECK-2 vector (Promega, Fitchburg, WI, USA). A QuikChange Site-Directed Mutagenesis kit (Agilent Technologies, CA, USA) was used to mutate the miR-1247-5p binding site (psiCHECK-2 Cyb5a 3′UTR mutant) according to the manufacturer’s protocol. All the sequences were verified by Sanger sequencing. Then, 200 ng of the plasmid was used for each transfection. Synthetic miR-1247-5p mimics and specific oligonucleotides that inhibit endogenous miR-1247-5p (miR-1247-5p inhibitors) were purchased from Promega and 100 nmol of the molecules were used for each transfection according to the manufacturer’s protocol. For the assay, HeLa cells were seeded in 96-well plates and incubated for 24 h. The following day, cells were transfected using the following different conditions: (1) psiCHECK-2 Cyb5a 3′UTR WT + miR-1247-5p mimic; (2) psiCHECK-2 Cyb5a 3′UTR WT + miR-1247-5p inhibitor; (3) psiCHECK-2 Cyb5a 3′UTR WT + water; (4) psiCHECK-2 Cyb5a 3′UTR mutant + miR-1247-5p mimic; (5) psiCHECK-2 Cyb5a 3′UTR mutant + miR-1247-5p inhibitor; (6) psiCHECK-2 Cyb5a 3′UTR mutant + water. Forty-eight hours later, luciferase activity in the cells was measured using the dual luciferase assay system (Promega, Fitchburg, WI, USA) in accordance with the manufacturer’s instructions. Renilla luciferase activity was normalized to firefly luciferase activity. Each treatment was performed in triplicate. Any interaction between the cloned gene, Cyb5a (WT and mutant), and miR-1247-5p mimic is accompanied by a decrease in luminescence. This decrease in luminescence would not be observed when the plasmids are transfected with the miR-1247-5p inhibitor, indicating that observed luminescence differences are caused by specific interactions between the plasmid and the miR-1247-5p mimic. Transfection of the plasmid with water corrects any background interactions between the cloned gene and endogenous miRNAs in the culture.

4.6. In Vivo ACTH Stimulation

Experiments were performed on 13-week-old C57BL/6 J female mice (Janvier, Le Genest-Saint-Isle, France). Mice were intraperitoneally injected with 1 mg/kg of ACTH (Sigma Aldrich, Munich, Germany) and adrenals were collected after 10, 30, and 60 min of injections. In addition, control adrenals were collected from mice at baseline conditions (0 min). Mice were killed by cervical dislocation and adrenals were isolated, snap-frozen in liquid nitrogen, and stored at −80 °C for later RNA extraction. MiR-26a was taken as a housekeeping gene in the QPCR [58]. All mice were maintained in accordance with facility guidelines on animal welfare and approved by Landesdirektion Sachsen, Chemnitz, Germany.

4.7. Statistical Analysis and Software

R version 3.6.1 was used for the statistical analyses. To identify RNAs differentially expressed, a generalized linear model (GLM, a flexible generalization of ordinary linear regression that allows for variables that have distribution patterns other than a normal distribution) in the software package edgeR (Empirical Analysis of DGE in R) was employed to calculate p-values [45,59]. p-values were adjusted using the Benjamin–Hochberg false discovery rate (FDR) procedure [60]. Disease groups were compared using the unpaired Mann–Whitney test, and to decrease the false discovery rate a corrected p-value was calculated using the Benjamin–Hochberg method. p adjusted < 0.05 and log2 fold change >1.25 was applied as the cut-off for significance for NGS data. GraphPad Prism Version 8 was used for the statistical analysis of QPCR. To calculate differential gene expression, the dCt method (delta Ct (cycle threshold) value equals target miRNA’s Ct minus housekeeping miRNA’s Ct) was used (Microsoft Excel 2016, Microsoft, Redmond, WA, USA). For QPCR, an ANOVA test with Bonferroni correction was used [61] to assess significance; p-values < 0.05 were considered significant.

5. Conclusions

In conclusion, while comprehensive information regarding the role of miRNAs in acute and chronic phases of steroidogenesis is available, there is little known about the pathological independent role of miRNAs in the pathology of CS. In our study, we have described ACTH-independent miR-1247-5p and miR-379-5p expression in CS for the first time. Thus, by regulating different genes in the WNT signaling pathway, the miRNAs may individually contribute to the Cushing’s pathology in specific subtypes.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/ijms23147676/s1.

Author Contributions

Conceptualization, S.V., A.C. and A.R.; methodology, S.V., R.Z. and M.E.; software, S.V. and M.E.; validation, R.Z., A.O., D.W. and B.W.; formal analysis, S.V.; investigation, S.V., R.Z., M.E., A.O. and D.W.; resources, A.C., B.W., M.R. and A.R.; data curation, S.V. and R.Z.; writing—original draft preparation, S.V., R.Z. and A.R.; writing—review and editing, S.S., M.R. and A.R.; visualization, S.V.; supervision, A.R.; project administration, A.R.; funding acquisition, A.C., S.S., M.R. and A.R. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) (within the CRC/Transregio 205/1 “The Adrenal: Central Relay in Health and Disease”) to A.C., B.W., S.S., M.R. and A.R., and individual grant SB 52/1-1 to S.S. This work is part of the German Cushing’s Registry CUSTODES and has been supported by a grant from the Else Kröner-Fresenius Stiftung to MR (2012_A103 and 2015_A228). A.R. was supported by the FöFoLe Program of the Ludwig Maximilian University, Munich. We thank I. Shapiro, A. Parl, C. Kühne, and S. Zopp for their technical support.

Institutional Review Board Statement

The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of the Ludwig Maximilian University, Munich (protocol code 379-10, 152-10 and 20 July2021).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The miRNA-seq data generated in this study have been submitted to the NCBI (PRJNA847385).

Conflicts of Interest

The authors declare no conflict of interest.

References

Kotłowska, A.; Puzyn, T.; Sworczak, K.; Stepnowski, P.; Szefer, P. Metabolomic biomarkers in urine of cushing’s syndrome pa-tients. Int. J. Mol. Sci. 2017, 18, 294. [Google Scholar] [CrossRef] [PubMed][Green Version]
Valassi, E.; Tabarin, A.; Brue, T.; Feelders, R.A.; Reincke, M.; Netea-Maier, R.; Toth, M.; Zacharieva, S.; Webb, S.M.; Tsagarakis, S.; et al. High mortality within 90 days of diagnosis in patients with Cushing’s syndrome: Results from the ERCUSYN registry. Eur. J. Endocrinol. 2019, 181, 461–472. [Google Scholar] [CrossRef]
Stratakis, C. Cushing syndrome caused by adrenocortical tumors and hyperplasias (corticotropin-independent Cushing syn-drome). Endocr. Dev. 2008, 13, 117–132. [Google Scholar]
Jarial, K.D.S.; Walia, R.; Nahar, U.; Bhansali, A. Primary bilateral adrenal nodular disease with Cushing’s syndrome: Varying aeti-ology. BMJ. Case. Rep. 2017, 2017, bcr2017220154. [Google Scholar] [CrossRef] [PubMed]
Kamilaris, C.D.C.; Stratakis, C.A.; Hannah-Shmouni, F. Molecular Genetic and Genomic Alterations in Cushing’s Syndrome and Primary Aldosteronism. Front. Endocrinol. 2021, 12, 142. [Google Scholar] [CrossRef] [PubMed]
Feelders, R.A.; Pulgar, S.J.; Kempel, A.; Pereira, A.M. The burden of Cushing’s disease: Clinical and health-related quality of life aspects. Eur. J. Endocrinol. 2012, 167, 311–326. [Google Scholar] [CrossRef] [PubMed][Green Version]
Feelders, R.A.; Newell-Price, J.; Pivonello, R.; Nieman, L.K.; Hofland, L.J.; Lacroix, A. Advances in the medical treatment of Cush-ing’s syndrome. Lancet Diabetes Endocrinol. 2019, 7, 300–312. [Google Scholar] [CrossRef]
Krill, K.T.; Gurdziel, K.; Heaton, J.H.; Simon, D.P.; Hammer, G.D. Dicer Deficiency Reveals MicroRNAs Predicted to Control Gene Expression in the Developing Adrenal Cortex. Mol. Endocrinol. 2013, 27, 754–768. [Google Scholar] [CrossRef]
Robertson, S.; Diver, L.A.; Alvarez-Madrazo, S.; Livie, C.; Ejaz, A.; Fraser, R.; Connell, J.M.; MacKenzie, S.M.; Davies, E. Regulation of Corticosteroidogenic Genes by MicroRNAs. Int. J. Endocrinol. 2017, 2017, 2021903. [Google Scholar] [CrossRef][Green Version]
Bujko, M.; Kober, P.; Boresowicz, J.; Rusetska, N.; Zeber-Lubecka, N.; Paziewska, A.; Pekul, M.; Zielinski, G.; Styk, A.; Kunicki, J.; et al. Differential microRNA Expression in USP8-Mutated and Wild-Type Corticotroph Pituitary Tumors Reflect the Difference in Protein Ubiquitination Processes. J. Clin. Med. 2021, 10, 375. [Google Scholar] [CrossRef]
Iliopoulos, D.; Bimpaki, E.I.; Nesterova, M.; Stratakis, C.A. MicroRNA Signature of Primary Pigmented Nodular Adrenocortical Disease: Clinical Correlations and Regulation of Wnt Signaling. Cancer Res. 2009, 69, 3278–3282. [Google Scholar] [CrossRef] [PubMed][Green Version]
Tan, X.-G.; Zhu, J.; Cui, L. MicroRNA expression signature and target prediction in familial and sporadic primary macronodular adrenal hyperplasia (PMAH). BMC Endocr. Disord. 2022, 22, 11. [Google Scholar] [CrossRef]
Vaczlavik, A.; Bouys, L.; Violon, F.; Giannone, G.; Jouinot, A.; Armignacco, R.; Cavalcante, I.P.; Berthon, A.; Letouzé, E.; Vaduva, P.; et al. KDM1A inactivation causes hereditary food-dependent Cushing syndrome. Genet. Med. 2021, 24, 374–383. [Google Scholar] [CrossRef]
Bimpaki, E.I.; Iliopoulos, D.; Moraitis, A.; Stratakis, C.A. MicroRNA signature in massive macronodular adrenocortical disease and implications for adrenocortical tumorigenesis. Clin. Endocrinol. 2010, 72, 744–751. [Google Scholar] [CrossRef]
Vetrivel, S.; Zhang, R.; Engel, M.; Altieri, B.; Braun, L.; Osswald, A.; Bidlingmaier, M.; Fassnacht, M.; Beuschlein, F.; Reincke, M.; et al. Circulating microRNA Expression in Cushing’s Syndrome. Front. Endocrinol. 2021, 12, 10. [Google Scholar] [CrossRef] [PubMed]
O’Brien, J.; Hayder, H.; Zayed, Y.; Peng, C. Overview of microRNA biogenesis, mechanisms of actions, and circulation. Front. Endocrinol. 2018, 9, 402. [Google Scholar] [CrossRef][Green Version]
Butz, H.; Patócs, A. MicroRNAs in endocrine tumors. Electron. J. Int. Fed. Clin. Chem. Lab. Med. 2019, 30, 146–164. [Google Scholar]
Riester, A.; Issler, O.; Spyroglou, A.; Rodrig, S.H.; Chen, A.; Beuschlein, F. ACTH-Dependent Regulation of MicroRNA As Endogenous Modulators of Glucocorticoid Receptor Expression in the Adrenal Gland. Endocrinology 2012, 153, 212–222. [Google Scholar] [CrossRef][Green Version]
Huang, X.; Zhong, R.; He, X.; Deng, Q.; Peng, X.; Li, J.; Luo, X. Investigations on the mechanism of progesterone in inhibiting endo-metrial cancer cell cycle and viability via regulation of long noncoding RNA NEAT1/microRNA-146b-5p mediated Wnt/β-catenin signaling. IUBMB Life 2019, 71, 223–234. [Google Scholar] [CrossRef][Green Version]
Azhar, S.; Dong, D.; Shen, W.-J.; Hu, Z.; Kraemer, F.B. The role of miRNAs in regulating adrenal and gonadal steroidogenesis. J. Mol. Endocrinol. 2020, 64, R21–R43. [Google Scholar] [CrossRef]
Allen, M.J.; Sharma, S. Physiology, Adrenocorticotropic Hormone (ACTH). StatPearls 2021. Available online: https://www.ncbi.nlm.nih.gov/books/NBK500031/ (accessed on 8 December 2021).
Hu, Z.; Shen, W.-J.; Cortez, Y.; Tang, X.; Liu, L.-F.; Kraemer, F.B.; Azhar, S. Hormonal Regulation of MicroRNA Expression in Steroid Producing Cells of the Ovary, Testis and Adrenal Gland. PLoS ONE 2013, 8, e78040. [Google Scholar] [CrossRef][Green Version]
Ghayee, H.K.; Rege, J.; Watumull, L.M.; Nwariaku, F.E.; Carrick, K.S.; Rainey, W.E.; Miller, W.L.; Auchus, R.J. Clinical, biochemical, and molecular characterization of macronodular adrenocortical hyperplasia of the zona reticularis: A new syndrome. J. Clin. Endocrinol. Metab. 2011, 96, E243–E250. [Google Scholar] [CrossRef] [PubMed][Green Version]
Nakamura, Y.; Fujishima, F.; Hui, X.-G.; Felizola, S.J.A.; Shibahara, Y.; Akahira, J.-I.; McNamara, K.M.; Rainey, W.E.; Sasano, H. 3βHSD and CYB5A double positive adrenocortical cells during adrenal development/aging. Endocr. Res. 2015, 40, 8–13. [Google Scholar] [CrossRef] [PubMed][Green Version]
Ng, L.F.; Kaur, P.; Bunnag, N.; Suresh, J.; Sung, I.C.H.; Tan, Q.H.; Gruber, J.; Tolwinski, N.S. WNT Signaling in Disease. Cells 2019, 8, 826. [Google Scholar] [CrossRef][Green Version]
Song, J.L.; Nigam, P.; Tektas, S.S.; Selva, E. microRNA regulation of Wnt signaling pathways in development and disease. Cell. Signal. 2015, 27, 1380–1391. [Google Scholar] [CrossRef][Green Version]
Beuschlein, F.; Fassnacht, M.; Assié, G.; Calebiro, D.; Stratakis, C.A.; Osswald, A.; Ronchi, C.L.; Wieland, T.; Sbiera, S.; Faucz, F.R.; et al. Constitutive Activation of PKA Catalytic Subunit in Adrenal Cushing’s Syndrome. N. Engl. J. Med. 2014, 370, 1019–1028. [Google Scholar] [CrossRef][Green Version]
Ren, J.; Jian, F.; Jiang, H.; Sun, Y.; Pan, S.; Gu, C.; Chen, X.; Wang, W.; Ning, G.; Bian, L.; et al. Decreased expression of SFRP2 promotes development of the pituitary corticotroph adenoma by upregulating Wnt signaling. Int. J. Oncol. 2018, 52, 1934–1946. [Google Scholar] [CrossRef][Green Version]
Pignatti, E.; Leng, S.; Yuchi, Y.; Borges, K.S.; Guagliardo, N.A.; Shah, M.S.; Ruiz-Babot, G.; Kariyawasam, D.; Taketo, M.M.; Miao, J.; et al. Beta-Catenin Causes Adrenal Hyperplasia by Blocking Zonal Transdifferentiation. Cell Rep. 2020, 31, 107524. [Google Scholar] [CrossRef]
Grumolato, L.; Liu, G.; Mong, P.; Mudbhary, R.; Biswas, R.; Arroyave, R.; Vijayakumar, S.; Economides, A.N.; Aaronson, S.A. Canonical and noncanonical Wnts use a common mechanism to activate completely unrelated coreceptors. Genes Dev. 2010, 24, 2517–2530. [Google Scholar] [CrossRef][Green Version]
Tauriello, D.V.F.; Jordens, I.; Kirchner, K.; Slootstra, J.W.; Kruitwagen, T.; Bouwman, B.A.M.; Noutsou, M.; Rüdiger, S.G.D.; Schwamborn, K.; Schambony, A.; et al. Wnt/β-catenin signaling requires interaction of the Dishevelled DEP domain and C terminus with a discontinuous motif in Frizzled. Proc. Natl. Acad. Sci. USA 2012, 109, E812–E820. [Google Scholar] [CrossRef][Green Version]
Colli, L.M.; Saggioro, F.; Neder Serafini, L.; Camargo, R.C.; Machado, H.; Moreira, A.C.; Antonini, S.R.; De Castro, M. Components of the Canonical and Non-Canonical Wnt Pathways Are Not Mis-Expressed in Pituitary Tumors. PLoS ONE 2013, 8, e62424. [Google Scholar] [CrossRef] [PubMed][Green Version]
Rosanò, L.; Cianfrocca, R.; Tocci, P.; Spinella, F.; Di Castro, V.; Caprara, V.; Semprucci, E.; Ferrandina, G.; Natali, P.G.; Bagnato, A. En-dothelin A receptor/β-arrestin signaling to the Wnt pathway renders ovarian cancer cells resistant to chemotherapy. Cancer Res. 2014, 74, 7453–7464. [Google Scholar] [CrossRef] [PubMed][Green Version]
Zhang, H.; Qiu, J.; Ye, C.; Yang, D.; Gao, L.; Su, Y.; Tang, X.; Xu, N.; Zhang, D.; Xiong, L.; et al. ROR1 expression correlated with poor clinical outcome in human ovarian cancer. Sci. Rep. 2014, 4, 5811. [Google Scholar] [CrossRef] [PubMed][Green Version]
Gao, Y.; Li, S.; Li, Q. Uterine epithelial cell proliferation and endometrial hyperplasia: Evidence from a mouse model. Mol. Hum. Reprod. 2014, 20, 776–786. [Google Scholar] [CrossRef]
Orang, A.V.; Safaralizadeh, R.; Kazemzadeh-Bavili, M. Mechanisms of miRNA-Mediated Gene Regulation from Common Downregulation to mRNA-Specific Upregulation. Int. J. Genom. 2014, 2014, 970607. [Google Scholar]
Huang, H.Y.; Lin, Y.C.D.; Li, J.; Huang, K.Y.; Shrestha, S.; Hong, H.C.; Tang, Y.; Chen, Y.G.; Jin, C.N.; Yu, Y.; et al. miRTarBase 2020: Up-dates to the experimentally validated microRNA–target interaction database. Nucleic Acids Res. 2020, 48, D148–D154. [Google Scholar] [CrossRef] [PubMed][Green Version]
Liu, W.; Wang, X. Prediction of functional microRNA targets by integrative modeling of microRNA binding and target expres-sion data. Genome Biol. 2019, 20, 18. [Google Scholar] [CrossRef] [PubMed]
Wang, X. Improving microRNA target prediction by modeling with unambiguously identified microRNA-target pairs from CLIP-ligation studies. Bioinformatics 2016, 32, 1316–1322. [Google Scholar] [CrossRef]
Martin, M. Cutadapt removes adapter sequences from high-throughput sequencing reads. EMBnet. J. 2011, 17, 10–12. [Google Scholar] [CrossRef]
Kozomara, A.; Griffiths-Jones, S. miRBase: Annotating high confidence microRNAs using deep sequencing data. Nucleic Acids Res. 2014, 42, D68–D73. [Google Scholar] [CrossRef][Green Version]
Griffiths-Jones, S. miRBase: The MicroRNA Sequence Database. Methods Mol. Biol. 2006, 342, 129–138. [Google Scholar] [PubMed]
Aparicio-Puerta, E.; Lebrón, R.; Rueda, A.; Gómez-Martín, C.; Giannoukakos, S.; Jáspez, D.; Medina, J.M.; Zubković, A.; Jurak, I.; Fromm, B.; et al. sRNAbench and sRNAtoolbox 2019: Intuitive fast small RNA profiling and differential expression. Nucleic Acids Res. 2019, 47, W530–W535. [Google Scholar] [CrossRef] [PubMed][Green Version]
Anders, S.; Huber, W. Differential expression analysis for sequence count data. Genome Biol. 2010, 11, R106. [Google Scholar] [CrossRef] [PubMed][Green Version]
Robinson, M.D.; McCarthy, D.J.; Smyth, G.K. EdgeR: A Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics 2010, 26, 139–140. [Google Scholar] [CrossRef][Green Version]
Liu, C.-H.; Di, Y.P. Analysis of RNA Sequencing Data Using CLC Genomics Workbench. Methods Mol. Biol. 2020, 2102, 61–113. [Google Scholar] [CrossRef]
Pfaffl, M.W.; Tichopad, A.; Prgomet, C.; Neuvians, T.P. Determination of stable housekeeping genes, differentially regulated target genes and sample integrity: BestKeeper–Excel-based tool using pair-wise correlations. Biotechnol. Lett. 2004, 26, 509–515. [Google Scholar] [CrossRef]
Wang, X.; Zhang, X.; Yuan, J.; Wu, J.; Deng, X.; Peng, J.; Wang, S.; Yang, C.; Ge, J.; Zou, Y. Evaluation of the performance of serum miRNAs as normalizers in microRNA studies focused on cardiovascular disease. J. Thorac. Dis. 2018, 10, 2599–2607. [Google Scholar] [CrossRef]
Geigges, M.; Gubser, P.M.; Unterstab, G.; Lecoultre, Y.; Paro, R.; Hess, C. Reference Genes for Expression Studies in Human CD8 + Naïve and Effector Memory T Cells under Resting and Activating Conditions. Sci. Rep. 2021, 10, 9411. [Google Scholar] [CrossRef]
Song, J.; Bai, Z.; Han, W.; Zhang, J.; Meng, H.; Bi, J.; Ma, X.; Han, S.; Zhang, Z. Identification of Suitable Reference Genes for qPCR Analysis of Serum microRNA in Gastric Cancer Patients. Dig. Dis. Sci. 2011, 57, 897–904. [Google Scholar] [CrossRef]
Szabó, D.R.; Luconi, M.; Szabó, P.M.; Tóth, M.; Szücs, N.; Horányi, J.; Nagy, Z.; Mannelli, M.; Patócs, A.; Rácz, K.; et al. Analysis of cir-culating microRNAs in adrenocortical tumors. Lab. Investig. 2014, 94, 331–339. [Google Scholar] [CrossRef][Green Version]
Butz, H.; Mészáros, K.; Likó, I.; Patocs, A. Wnt-Signaling Regulated by Glucocorticoid-Induced miRNAs. Int. J. Mol. Sci. 2021, 22, 11778. [Google Scholar] [CrossRef] [PubMed]
Muñoz, J.J.; Anauate, A.C.; Amaral, A.G.; Ferreira, F.M.; Watanabe, E.H.; Meca, R.; Ormanji, M.S.; Boim, M.A.; Onuchic, L.F.; Heilberg, I.P. Ppia is the most stable housekeeping gene for qRT-PCR normalization in kidneys of three Pkd1-deficient mouse models. Sci. Rep. 2021, 11, 19798. [Google Scholar] [CrossRef] [PubMed]
Xia, X.; Liu, Y.; Liu, L.; Chen, Y.; Wang, H. Selection and verification of the combination of reference genes for RT-qPCR analysis in rat adrenal gland development. J. Steroid. Biochem. Mol. Biol. 2021, 208, 105821. [Google Scholar] [CrossRef] [PubMed]
Gillespie, M.; Jassal, B.; Stephan, R.; Milacic, M.; Rothfels, K.; Senff-Ribeiro, A.; Griss, J.; Sevilla, C.; Matthews, L.; Gong, C.; et al. The reactome pathway knowledgebase 2022. Nucleic Acids Res. 2022, 50, D687–D692. [Google Scholar] [CrossRef]
Mi, H.; Ebert, D.; Muruganujan, A.; Mills, C.; Albou, L.-P.; Mushayamaha, T.; Thomas, P.D. PANTHER version 16: A revised family classification, tree-based classification tool, enhancer regions and extensive API. Nucleic Acids Res. 2021, 49, D394–D403. [Google Scholar] [CrossRef]
Wu, T.; Lin, Y.; Xie, Z. MicroRNA-1247 inhibits cell proliferation by directly targeting ZNF346 in childhood neuroblastoma. Biol. Res. 2018, 51, 13. [Google Scholar] [CrossRef][Green Version]
Muñoz, J.J.; Anauate, A.; Amaral, A.G.; Ferreira, F.M.; Meca, R.; Ormanji, M.S.; Boim, M.A.; Onuchic, L.F.; Heilberg, I.P. Identification of housekeeping genes for microRNA expression analysis in kidney tissues of Pkd1 deficient mouse models. Sci. Rep. 2020, 10, 231. [Google Scholar] [CrossRef][Green Version]
Love, M.I.; Huber, W.; Anders, S. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2. Genome Biol. 2014, 15, 550. [Google Scholar] [CrossRef][Green Version]
Hu, Z.; Gao, S.; Lindberg, D.; Panja, D.; Wakabayashi, Y.; Li, K.; Kleinman, J.E.; Zhu, J.; Li, Z. Temporal dynamics of miRNAs in human DLPFC and its association with miRNA dysregulation in schizophrenia. Transl. Psychiatry 2019, 9, 196. [Google Scholar] [CrossRef]
Esteva-Socias, M.; Gómez-Romano, F.; Carrillo-Ávila, J.A.; Sánchez-Navarro, A.L.; Villena, C. Impact of different stabilization methods on RT-qPCR results using human lung tissue samples. Sci. Rep. 2020, 10, 3579. [Google Scholar] [CrossRef]

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Filed under: Clinical trials, Cushing's | Tagged: ACTH, adrenalectomy, bilateral adrenalectomy, BLA, cortisol, hypercortisolism, miRNA, pituitary | Leave a comment »

Association of Chronic Central Serous Chorioretinopathy with Subclinical Cushing’s Syndrome

Posted on March 30, 2022 by MaryO

https://doi.org/10.1016/j.ajoc.2022.101455

Abstract

Purpose

To report the clinical course of a patient with central serous chorioretinopathy (CSCR) secondary to subclinical hypercortisolism before and after adrenalectomy.

Observations

A 50-year-old female patient with multifocal, chronic CSCR was found to have an adrenal incidentaloma and was diagnosed with subclinical hypercortisolism. Patient elected to undergo minimally-invasive adrenalectomy and presented at 3 months after surgery without subretinal fluid.

Conclusions and Importance

Subclinical Cushing’s Syndrome (SCS) may present an underrecognized risk factor for developing chronic CSCR. Further investigation is needed to determine the threshold of visual comorbidity that may influence surgical management.

Keywords

Central serous chorioretinopathy

Subclinical Cushing’s syndrome

Hypercortisolism

Adrenalectomy

Retina

Surgical intervention

1. Introduction

Central serous chorioretinopathy (CSCR) is characterized by accumulation of fluid in the subretinal or sub-RPE space, often with consequential visual impairment. Chronic CSCR has been reported as a manifestation of hypercortisolism due to Cushing’s syndrome and subclinical hypercortisolism.¹^,² However, the latter is often underrecognized owing to its inherently subtle nature and the optimal threshold for intervention based on associated comorbidities remains unclear. Herein we report the clinical course of a patient with CSCR secondary to subclinical hypercortisolism before and after adrenalectomy.

2. Case report

A 50-year-old female presented with blurred, discolored spots in the right eye for several months. Her past medical history included mild hypertension treated with amlodipine. Past ocular and family history were noncontributory.

On exam, Snellen visual acuity was 20/50 OD, 20/25 OS. Her pupils, intraocular pressure, and anterior segment exam were within normal limits. Dilated fundus exam revealed bilateral, multifocal areas of subretinal fluid and mottled pigmentary changes (Fig. 1A). Optical coherence tomography confirmed areas of subretinal fluid and other areas of outer retinal atrophy (Fig. 1B). Fundus autofluorescence revealed areas of hyperautofluorescence that highlighted the fundoscopic findings (Fig. 1C). Fluorescein angiography showed multifocal areas of expansile dot leakage (Fig. 1D). Altogether these findings were consistent with multifocal, chronic CSCR.

On further clinical follow-up, an adrenal incidentaloma (AI) was detected when the patient underwent imaging for back pain. Subsequently she saw an endocrinologist; she had a normal serum cortisol, but low ACTH and an abnormal dexamethasone suppression test. This led to a diagnosis of subclinical hypercortisolism and provided a reason for her hypertension and chronic CSCR.

Since the blur and relative scotomata interfered with her daily activities, she elected to try eplerenone, which yielded a moderate but suboptimal therapeutic response at 50 mg daily. While contemplating photodynamic therapy, in discussion with her endocrinologist, the patient opted to undergo minimally-invasive adrenalectomy. At last follow-up 3 months after surgery and 6 years after her initial presentation, she has been off eplerenone and without subretinal fluid (Fig. 2).

3. Discussion

CSCR has previously been associated with many risk factors including exposure to excess steroid. A recent study analyzing a nationally representative dataset of 35,000 patients found that patients with CSCR had a higher odds of Cushing’s syndrome (OR 2.19, 95% CI 1.33 to 3.59, p = 0.002) than exposure to exogenous steroids (OR 1.14, 95% CI 1.09 to 1.19, p < 0.001)¹ Our case highlights the importance of thorough medication reconciliation and careful consideration of comorbid conditions in patients with chronic CSCR.

In recent years, subtle endogenous hypercortisolism, termed subclinical Cushing’s syndrome (SCS), has been of particular interest in the endocrinology literature because it can be a challenging diagnosis and the most appropriate management remains controversial.³ In general, SCS is comprised of: 1) the presence of an adrenal incidentaloma or mass, 2) biochemical confirmation of cortisol excess, and 3) no classic phenotypic manifestations of Cushing’s syndrome.⁴ Since adrenal incidentaloma has an estimated prevalence of 1–8% of the population,⁵ it is quite possible that SCS is an underrecognized risk factor for CSCR.

SCS may potentiate metabolic syndrome and osteoporosis; studies have found that surgical resection of adrenal incidentalomas improve weight, blood pressure, and glucose control. Consequently, some authors recommend those with SCS-associated comorbidities be considered for resection.⁶ An important consideration in these patients is how visual comorbidity factors into intervention. In our patient’s case, the recurrent CSCR, hypertension, and increased risk of metabolic syndrome were sufficient reasons to elect to have surgery.

4. Conclusion

In summary, SCS is a condition of subtle cortisol dysregulation that may represent an underrecognized risk factor for chronic CSCR. Further investigation is needed to determine the threshold of visual comorbidity that may influence surgical management.

Patient consent

Consent to publish the case report was not obtained. This report does not contain any personal information that could lead to the identification of the patient.

Acknowledgments and Disclosures

Grant support was from the J. Arch McNamara Retina Research Fund. The following authors have no financial disclosures: RRS, AS, AC All authors attest that they meet the current ICMJE criteria for Authorship. No other contributions to acknowledge.

References

1: M. Zhou, S.J. Bakri, S. Pershing

Risk factors for incident central serous retinopathy: case-control analysis of a US national managed care population

Br J Ophthalmol, 103 (12) (2019), pp. 1784-1788, 10.1136/bjophthalmol-2018-313050

View PDF

View Record in Scopus Google Scholar
2: S.N. Appa

Subclinical hypercortisolism in central serous chorioretinopathy

Retin Cases Brief Rep, 8 (4) (2014), pp. 310-313, 10.1097/ICB.0000000000000036

View PDF

View Record in Scopus Google Scholar
3: I. Chiodini, A. Albani, A.G. Ambrogio, et al.

Six controversial issues on subclinical Cushing’s syndrome

Endocrine, 56 (2) (2017), pp. 262-266, 10.1007/s12020-016-1017-3

View PDF

View Record in Scopus Google Scholar
4: M.A. Zeiger, G.B. Thompson, Q.-Y. Duh, et al.

American association of clinical endocrinologists and American association of endocrine surgeons medical guidelines for the management of adrenal incidentalomas: executive summary of recommendations

Endocr Pract Off J Am Coll Endocrinol Am Assoc Clin Endocrinol, 15 (5) (2009), pp. 450-453, 10.4158/EP.15.5.450

Article Download PDF Google Scholar
5: M. Terzolo, A. Stigliano, I. Chiodini, et al.

AME position statement on adrenal incidentaloma

Eur J Endocrinol, 164 (6) (2011), pp. 851-870, 10.1530/EJE-10-1147

View PDF

View Record in Scopus Google Scholar
6: L.B. Hsieh, E. Mackinney, T.S. Wang

When to intervene for subclinical cushing’s syndrome

Surg Clin North Am, 99 (4) (2019), pp. 747-758, 10.1016/j.suc.2019.04.011

Article Download PDF View Record in Scopus Google Scholar

From https://www.sciencedirect.com/science/article/pii/S2451993622002018?via%3Dihub#!

Filed under: Cushing's, symptoms, Treatments | Tagged: adrenalectomy, central serous chorioretinopathy, subclinical Cushing's syndrome | Leave a comment »

Adrenalectomy in ectopic Cushing’s syndrome: A retrospective cohort study from a tertiary care centre

Posted on September 13, 2021 by MaryO

Ieva Lase, Malin Grönberg, Olov Norlén, Peter Stålberg, Staffan Welin, Eva Tiensuu Janson

First published: 13 August 2021

https://doi.org/10.1111/jne.13030

Abstract

Neuroendocrine neoplasms (NENs) causing ectopic Cushing’s syndrome (ECS) are rare and challenging to treat. In this retrospective cohort study, we aimed to evaluate different approaches for bilateral adrenalectomy (BA) as a treatment option in ECS. Fifty-three patients with ECS caused by a NEN (35 females/18 men; mean ± SD age: 53 ± 15 years) were identified from medical records. Epidemiological and clinical parameters, survival, indications for surgery and timing, as well as duration of surgery, complications and surgical techniques, were collected and further analysed. The primary tumour location was thorax (n = 30), pancreas (n = 14) or unknown (n = 9). BA was performed in 37 patients. Median time from diagnosis of ECS to BA was 2 months (range 1–10 months). Thirty-two patients received different steroidogenesis inhibitors before BA to control hypercortisolaemia. ECS resolved completely after surgery in 33 patients and severe peri- or postoperative complications were detected in 12 patients. There were fewer severe complications in the endoscopic group compared to open surgery (p = .030). Posterior retroperitoneoscopic BA performed simultaneously by a two surgeon approach had the shortest operating time (p = .001). Despite the frequent use of adrenolytic treatment, BA was necessary in a majority of patients to gain control over ECS. Complication rate was high, probably as a result of the combination of metastatic disease and metabolic disorders caused by high cortisol levels. The two surgeon approach BA may be considered as the method of choice in ECS compared to other BA approaches as a result of fewer complications and a shorter operating time.

1 INTRODUCTION

Endogenous Cushing’s syndrome (CS) has an estimated incidence of 0.2–5.0 per million people per year.¹ In 5–10% of these, it is caused by ectopic secretion of adrenocorticotrophic hormone (ACTH) or, in extremely rare cases, corticotrophin-releasing hormone, from a non-pituitary tumour.^1, 2

The treatment of neuroendocrine neoplasms (NENs) with ectopic secretion of ACTH is challenging. Because of the rarity and heterogeneity of this condition, there is no established evidence-based recommendation.³ Most patients with ectopic Cushing’s syndrome (ECS) have severe hypercortisolaemia leading to disrupted electrolyte and glucose levels, metabolic alkalosis, thrombosis and life-threatening infections, amongst many other manifestations. Initiation of oncological treatment is often delayed as a result of the consequences of high cortisol levels. A reduction of the cortisol level is crucial for survival and hypercortisolaemia and hypokalaemia are negative prognostic factors.^4, 5 If radical surgery of the tumour is not possible because of metastatic disease, normo-cortisolaemia can be achieved either by medical treatment with steroidogenesis inhibitors (SI) or bilateral adrenalectomy (BA),⁶ and BA has also been considered a treatment option for patients with occult or cyclic ECS. In patients with metastatic neuroendocrine carcinomas, platinum-based chemotherapy may be applied as first-line action, combined by SI and/or followed by BA. Computed tomography-guided percutaneous adrenal ablation has been reported in several case reports as a possible therapeutic alternative for patients in whom medical treatment has failed and BA is not feasible,^7–10 althhough more data is needed to recommend this method in daily practice.

In the 1930s, transabdominal open access BA was introduced as a treatment option for uncontrolled cortisol secretion.¹¹ Sixty years later, in the 1990s, laparoscopic methods were established^12, 13 and are now considered as the gold standard for BA (except for adrenal carcinomas) because they result in less postoperative pain, a shorter hospitalisation time and faster recovery.¹⁴ Laparoscopic transperitoneal adrenalectomy (LTA) is the most frequently applied surgical method. However, posterior retroperitoneoscopic adrenalectomy (PRA), introduced in 1995 by Walz et al,¹⁵ is gaining popularity.¹⁶ Using PRA compared to LTA offers a more direct approach to the adrenal glands, a shorter operating time (no need for reposition of the patient), less blood loss and faster recovery, and it aso has advantages for patients with obesity or a history of previous abdominal surgery.¹⁶ There are centres where PRA is performed by a two surgeon approach; thus, a simultaneous bilateral approach offers the possibility of decreasing the surgical time by up to 50% and reducing operative stress.^17–19

The present study aimed to evaluate BA as a treatment option for ECS, as well as the effects of different approaches on morbidity and mortality. We hypothesised that endoscopic surgery methods could be superior regarding complication rate, operating and hospitalisation time compared to open access surgery and also influence overall survival.

2 MATERIALS AND METHODS

2.1 Patients and data

A cohort of 59 patients with ECS was identified retrospectively from medical records of 894 patients with NENs, referred to the Department of Endocrine Oncology, Uppsala University Hospital between 1984 and 2019. None of the patients had a small-cell lung cancer (SCLC) because these tumours are not treated at our centre and possibly have a different mechanism behind ACTH production compared to that of NENs. Furthermore, SCLCs have a much more severe course of disease compared to well differentiated NENs and including them in the present study could mask any results important for NEN clinical management. Six patients were from outside Sweden and were excluded from further analysis because of a lack of follow-up data; thus, in total, 53 patients were available for analysis. Diagnosis of ECS was confirmed by histopathological examination of tumour specimen (n = 48) together with the clinical and biochemical picture of ACTH-dependent Cushing’s syndrome (elevated serum and urinary cortisol, high ACTH and pathological functional tests). In five patients where neither primary tumor, nor metastatic disease was found despite several PET examinations, including ⁶⁸Ga- DOTATOC-PET, ¹¹C-5HTP-PET and ¹⁸FDG-PET in four of the five patients, ECS was confirmed on the basis of the clinical/biochemical picture and exclusion of pituitary origin by magnetic resonance imaging, as well as inferior sinus petrosus sampling.

Epidemiological data, data on clinical parameters, survival, indication and duration of surgery, complications and surgical technique were extracted and further analysed.

2.2 Surgery

BA was performed either by an open access approach, LTA or PRA. PRA was performed either by one surgeon (PRA-1S) or by two surgeons operating on both sides simultaneously (PRA-2S). Some patients were operated twice (one adrenal at the time) and, for those patients, operating time was pooled from both surgeries, if both sessions were performed within 1 week. Cases where conversion from an endoscopic to an open access approach was made peroperatively were grouped as open access surgery in further analysis. Patients who died during the postoperative stage (within 30 days) were excluded from calculation of hospitalisation time.

Postoperative complications were graded using the Clavien–Dindo classification where complications of Grade 1 are defined as “any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions. Allowed therapeutic regimens are drugs as antiemetics, antipyretics, analgesics, diuretics and electrolytes and physiotherapy”.²⁰ Because almost all patients had mild, Grade 1 postoperative complications (metabolic disturbances caused by hypercortisolaemia), this variable is not described. We defined complications up to Grade 2 as mild and Grade 3–5 as severe.

2.3 Statistical analysis

All parameters were analysed by descriptive statistics: normally distributed data as the mean ± SD, and data with skewed distribution and/or outliers were described as medians, accompanied by the 25th to 75th percentile ranges (Q1-Q3) or minimum-maximum (min-max). The defined event was death from any cause. Overall survival (OS) was defined as time from diagnosis of ECS or time of BA until date of death or, if the event was not found, censored at date of last observation, 31 December 2019. Kaplan-Meier plots were used for survival analysis and the log-rank test was used for comparison. Chi-squared was used for testing relationships between categorical variables. p < .05 was considered statistically significant. All statistical analyses were performed using IBM, version 27 (IBM Corp., Armonk, USA).

3 RESULTS

3.1 Studied patients

ECS represented six% (n = 59) of NENs in our cohort. Six patients were excluded from further analysis, resulting in 53 ECS patients who were analysed; there were 35 females and 18 males with a mean ± SD age of 53 ± 15 years. The localisation of the primary NEN was thorax (n = 30), pancreas (n = 14) or unknown (n = 9). Histopathological staining for Ki-67 was available in 38 patients and Ki-67 was < 2% in five patients, 3–20% in 22 patients and > 20% in 11 patients. Patient characteristics are shown in Tables 1 and 2. Twenty-two patients (41.5%) in this cohort had concomitant hypersecretion of hormones other than ACTH from their tumour (5-HIAA, n = 10; calcitonin, n = 3; 5-HIAA + calcitonin, n = 2; glucagon, n = 3, gastrin, n = 2; growth hormone, n = 1; insulin + gastrin + vasointestinal peptide, n = 1).

3.2 Surgery

Adrenalectomy was performed in 37 patients (70%); 24 patients were operated at Uppsala University Hospital, nine at Karolinska University Hospital in Stockholm and four at Umeå University Hospital. Median time from diagnosis of ECS to BA was 2 months (range 1–10 months). Median Ki-67 in patients who were operated within 2 months after ECS diagnosis was higher (Ki-67 18.5%) compared to those with BA performed later in the course of disease (Ki-67 9.5%), although the difference was not statistically significant (p = .085).

Thirty-two (86%) patients received different SI prior to BA to control hypercortisolaemia. Eight of those were treated with chemotherapy as well in an attempt to reduce cortisol levels. The majority of patients was treated with ketoconazole, often in combination with other drugs (Table 3). Indications for BA in our cohort included (1) persistent hypercortisolaemia despite use of SI (n = 30); (2) BA as first choice of treatment to reduce cortisol levels (n = 5); and (3) no effect combined with severe side effects from SI including liver toxicity and severe leukopenia (n = 2). In 16 patients, BA was not performed as a result of (1) good control of ECS with SI (n = 4); (2) radical surgery of the primary tumour (n = 3); (3) good control of ECS with SI followed by radical surgery of the primary tumour (n = 5) and (4) the bad condition of the patient (n = 4).

3.3 Survival analysis

There was no operative mortality in this cohort. Four patients died within 1 month after adrenalectomy (on day 5, 16, 22 and 30, respectively) as a result of multiple organ dysfunction syndrome and progression of NEN. At the end of the follow-up period, 14 patients were still alive and 39 had died.

Median survival after BA was 24 months (95% confidence interval [CI] = 7–41, min-max: 0–428) with a 5-year survival of 22%. Median follow-up time for all patients from time of ECS diagnosis was 26 (range 6–62) months and after BA was 19 (range 3–50) months. OS was longer in patients where ECS was treated by radical surgery of the primary tumour or where good biochemical control was achieved by SI compared to patients who underwent BA, 96 months (95% CI 0–206) vs 29 months (95% CI 7–51), respectively. However, this difference was not statistically significant (p = .086), most likely as a result of the small sample size. Multiple hormone secretion correlated with shorter OS after BA (p = .009; hazard ratio = 2.9; 95% CI= 1.3–6.7). There was no significant difference in OS after BA depending on localisation of primary tumour (thoracic NENs 24 months [95% CI = 8–40, min-max: 0–428], pancreatic NENs 19 months [95% CI = 0–43, min-max: 0–60], p = .319) or surgical approach (open access approach 24 months [95% CI = 1–47], endoscopic approach 19 months [95% CI = 1–37], p = .720).

Median time from ECS diagnosis to BA was 2 months (range 1–10). Patients who underwent BA within 2 months after ECS diagnosis had shorter OS compared to those who were operated at a later stage: 6 months (95% CI = 0–18) and 45 months (95% CI = 3–86) respectively (p = .007). The former group had a slightly higher median Ki-67 level (18% vs 9%), lower potassium (2.7 mmol L^-1 vs 3.0 mmol L^-1) and higher hormone levels (ACTH 217 vs 120 ng mL^-1, morning cortisol 1448 vs 1181 nmol L^-1 and UFC 5716 vs 4234 nmol per 24 h) at diagnosis compared to those who were operated later in the course of disease.

4 DISCUSSION

The present study highlights new aspects of the advantages of an endoscopic approach of BA compared to open access surgery, regarding the incidence of severe complications graded using the Clavien-Dindo classification, as well as operation- and hospitalisation time. Our results indicate that PRA performed by two surgeons simultaneously is the method of choice for patients with ECS. However, despite these advantages, the endoscopic approach did not appear to improve overall survival.

Recent Endocrine Society guidelines recommend SI as primary treatment for ECS in patients with occult or metastatic ECS followed by BA.⁶ Although the toxicity of SI in our cohort was low (n = 2; 6%), 32 patients (73%) had persistent hypercortisolaemia despite medical treatment and proceeded to BA. BA, especially with an endoscopic approach, with a short operating time and low complication risk, appears to play a major role in the appropriate management of hypercortisolaemia in ECS, where rapid reduction of cortisol levels is very important.

Prolonged exposure to high cortisol levels, in combination with high risk for hepatotoxic and nephrotoxic SI side effects, increases morbidity and risk for severe complications, and often delays the start of oncological treatment. However, the trauma caused by surgery can also postpone initiation of chemotherapy.²¹ Therefore, a fast and minimally invasive surgical procedure appears to be a crucial factor for the better survival in ECS. The endoscopic approach is now considered as the gold standard for BA. Our study presents fewer severe complications, as well as shorter operating and hospitalisation times, when the endoscopic approach is compared with open surgery. In line with previous studies,^19, 22 we observed a significantly shorter operating time when applying PRA compared to LTA because there is no need for repositioning of the patient during PRA. PRA-2S had the shortest operating time and should be considered as the best choice of surgical approach in ECS. This result ties well with previous studies reporting the median operating time to be between 43 and 157 min in PRA-2S, which is significantly shorter compared to LTA and PRA-1S.^17–19

The median time from diagnosis to BA was 2 months, which is consistent with a previous study.²³ However, OS was significantly shorter in patients who were operated within 2 months after diagnosis of ECS in our cohort compared to those operated at a later stage. These early operated patients probably had a more aggressive clinical course of disease, as indicated by slightly higher median Ki-67, lower potassium and higher hormone levels at diagnosis, and they were operated as a result of more acute indications (without time to proper pre-treatment with SI) than the other group.

In our previous report on patients with ACTH-producing NENs, multiple hormone secretion was identified as the strongest indicator of a worse prognosis.⁴ A similar pattern of results was observed in this cohort, showing that patients with NENs, with concomitant hypersecretion of other hormones than ACTH from their tumour, had a shorter OS after BA compared to those with ACTH hypersecretion only.

As a result of the extremely high preoperative cortisol levels in ECS, the substitution therapy needed after successful BA may be challenging.²¹ Over-replacement of glucocorticoids may lead to higher morbidity²⁴ and mortality, especially in patients with metastatic NENs, who often have impaired immune function because of oncological treatment. Many patients suffer from glucocorticoid withdrawal syndrome, despite adequate replacement therapy, and it can take ≥ 1 year to gain control over these symptoms.⁶ This frequently leads to high dosage of glucocorticoids. The Endocrine Society guidelines recommend glucocorticoid replacement with hydrocortisone, 10–12 mg m^-2 day^-1 in divided doses.⁶ If we assume that most of our patients have body surface area around 2 m² or less, the daily hydrocortisone dose should not exceed 25 mg. However, 1 year after BA, only one patient received 25 mg of hydrocortisone daily, with the majority receiving 30 mg or more. One-third of the patients had residual arterial hypertension and diabetes 3 months after BA, probably partially depending on too high a dose of glucocorticoids.

There was a higher complication rate in our cohort compared to other studies^19, 25, 26 and five patients needed conversion from an endoscopic approach to open surgery. In particular, the outcome of BA in ECS has not previously been systematically evaluated²⁷ because most of the reports include patients with various aetiologies of CS.^{19, 22, 23, 28, 29} In a systematic review of the literature published between 1980 and 2012 on BA in CS, Reincke et al²³ identified 37 studies and ECS was present in 13% of the patients. There are only few papers focused on BA in ECS solely^{21, 25, 26, 30, 31} and only one has a cohort with > 50 patients (n = 54).²⁶ Patients with ECS have almost always a more aggressive course and more severe metabolic disturbance than patients with other types of Cushing’s syndrome, which probably leads to higher risk for postoperative complications. Furthermore, multiple liver metastases, fibrotic processes in the abdomen as a result of previous surgery or large primary tumour in pancreas could be some of the factors influencing surgical outcome in ECS.

The present study has several limitations. First, all data were collected retrospectively from patient records and not all the preferred parameters were available for all patients. Second, even if our cohort is one of the largest regarding studies on BA in ECS, the number of patients is too low for reliable statistical analysis. Finally, our study covered more than three decades, BAs were performed at different clinics and by different surgeons. Therefore, the data should be interpreted carefully.

In conclusion, the present study is one of few reports focusing on BA in specifically NEN patients with ECS and includes one of the largest patient cohorts analysed in the field. PRA-2S can be considered as method of choice in ECS compared to other BA approaches. The aim is to avoid administrating too high a hydrocortisone replacement dosage postoperatively because this can worsen the metabolic disturbance. As a result of the rarity of the condition, multicentre studies are needed with large, prospective cohorts and standardised inclusion criteria, aiming to further improve our knowledge about the management of ECS.

ACKNOWLEDGEMENTS

This study was funded by the Swedish Cancer Society (grant number CAN 18 0576), the Lions Foundation for Cancer Research at Uppsala University Hospital, Selanders Foundation and Söderbergs foundation at Uppsala University.

CONFLICT OF INTERESTS

The authors declare that they have no conflicts of interest.

AUTHOR CONTRIBUTIONS

Ieva Lase: Conceptualisation; Data curation; Formal analysis; Investigation; Methodology; Visualisation; Writing – original draft; Writing – review & editing. Malin Grönberg: Formal analysis; Supervision; Visualisation; Writing – review & editing. Olov Norlén: Conceptualisation; Writing – review & editing. Peter Stålberg: Conceptualisation; Writing – review & editing. Staffan Welin: Conceptualisation; Supervision; Writing – review & editing. Eva Tiensuu Janson: Conceptualisation; Funding acquisition; Methodology; Supervision; Writing – review & editing.

ETHICAL APPROVAL

The need for informed consent was waived by the local ethics committee. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study was approved by the local ethics committee, Regionala etikprövningsnämnden (EPN), in Uppsala, Sweden.

PEER REVIEW

The peer review history for this article is available at https://publons.com/publon/10.1111/jne.13030.

The entire article, PDF, supporting tables and more can be found at https://onlinelibrary.wiley.com/doi/full/10.1111/jne.13030

Filed under: Cushing's, Rare Diseases, Treatments | Tagged: adrenalectomy, ectopic | Leave a comment »

Even in Remission, Cushing’s Patients Have Excess Mortality

Posted on March 11, 2019 by MaryO

Cushing’s disease patients in Sweden have a higher risk of death than the general Swedish population, particularly of cardiovascular complications, and that increased risk persists even in patients in remission, a large nationwide study shows.

The study, “Overall and disease-specific mortality in patients with Cushing’s disease: a Swedish nationwide study,” was published in the Journal of Clinical Endocrinology and Metabolism.

The outcomes of Cushing’s disease patients have improved with the introduction of several therapeutic approaches, such as minimally invasive surgery and cortisol-lowering therapies. However, mortality is still high, especially among those who do not achieve remission.

While currently patients in remission are thought to have a better prognosis, it is still unclear whether these patients still have a higher mortality than the general population. Understanding whether these patients are more likely to die and what risk factors are associated with increased mortality is critical to reduce death rates among Cushing’s patients.

A team of Swedish researchers thus performed a retrospective study that included patients diagnosed with Cushing’s disease who were part of the Swedish National Patient Registry between 1987 and 2013.

A total of 502 patients with Cushing’s disease were included in the study, 419 of whom were confirmed to be in remission. Most patients (77%) were women; the mean age at diagnosis was 43 years, and the median follow-up time was 13 years.

During the follow-up, 133 Cushing’s patients died, compared to 54 expected deaths in the general population — a mortality rate 2.5 times higher, researchers said.

The most common causes of death among Cushing’s patients were cardiovascular diseases, particularly ischemic heart disease and cerebral infarctions. However, infectious and respiratory diseases (including pneumonia), as well as diseases of the digestive system, also contributed to the increased mortality among Cushing’s patients.

Of those in remission, 21% died, compared to 55% among those not in remission. While these patients had a lower risk of death, their mortality rate was still 90% higher than that of the general population. For patients who did not achieve remission, the mortality rate was 6.9 times higher.

The mortality associated with cardiovascular diseases was increased for both patients in remission and not in remission. Also, older age at the start of the study and time in remission were associated with mortality risk.

“A more aggressive treatment of hypertension, dyslipidemia [abnormal amount of fat in the blood], and other cardiovascular risk factors might be warranted in patients with CS in remission,” researchers said.

Of the 419 patients in remission, 315 had undergone pituitary surgery, 102 had had their adrenal glands removed, and 116 had received radiation therapy.

Surgical removal of the adrenal glands and chronic glucocorticoid replacement therapy were associated with a worse prognosis. In fact, glucocorticoid replacement therapy more than twice increased the mortality risk. Growth hormone replacement was linked with better outcomes.

In remission patients, a diagnosis of diabetes mellitus or high blood pressure had no impact on mortality risk.

Overall, “this large nationwide study shows that patients with [Cushing’s disease] continue to have excess mortality even after remission,” researchers stated. The highest mortality rates, however, were seen in “patients with persistent disease, those who were treated with bilateral adrenalectomy and those who required glucocorticoid replacement.”

“Further studies need to focus on identifying best approaches to obtaining remission, active surveillance, adequate hormone replacement and long-term management of cardiovascular and mental health in these patients,” the study concluded.

From https://cushingsdiseasenews.com/2019/02/28/even-in-remission-cushings-patients-have-excess-mortality-swedish-study-says/

Filed under: adrenal, Cushing's, pituitary, Treatments | Tagged: adrenalectomy, BLA, cardiovascular, growth hormone (GH), mortality, pituitary surgery, pneumonia, radiation, remission, surgery | 1 Comment »

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Meta

Association Between Aldosterone and Hypertension Among Patients With Overt and Subclinical Hypercortisolism

Abstract

Materials and Methods

Data Sources and Study Participants

Measurements

Statistical Analyses

Results

Demographic Characteristics and Endocrine Parameters Among Patients With Overt and Subclinical Hypercortisolism

Association of Demographic Characteristics and Endocrine Parameters With Systolic Blood Pressure

Association of Demographic Characteristics and Endocrine Parameters With Hypertension Improvement After the Adrenalectomy Among Patients With Subclinical Hypercortisolism

Additional Analyses

Discussion

Funding

Conflicts of Interest

Data Availability

Abbreviations

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Characterization of Adrenal miRNA-Based Dysregulations in Cushing’s Syndrome

Abstract

1. Introduction

2. Results

2.1. Differentially Expressed miRNAs

2.2. Validation and Selection of Candidate miRNAs

2.3. In Vivo Assessment of ACTH-Independent miR-1247-5p

2.4. In Silico Analyses of miRNA Targets

2.5. In Vitro Analyses of miR-1247-5p Targets

2.6. Pathway Analyses of miRNA Targets

3. Discussion

3.1. ACTH-Independent Upregulated miRNAs in CS

3.2. Target Genes of miRNAs in CS

3.3. Pathway Analyses of miRNA Targets

3.4. MiRNA Target Genes in WNT Signaling

3.5. Bottlenecks and Future Outlook

4. Materials and Methods

4.1. Sample Collection and Ethics Approval

4.2. MiRNA and RNA Sequencing

4.3. Validation of Individual miRNAs

4.4. Target Screening

4.5. Dual Luciferase Assay

4.6. In Vivo ACTH Stimulation

4.7. Statistical Analysis and Software

5. Conclusions

Supplementary Materials

Author Contributions

Funding

Institutional Review Board Statement

Informed Consent Statement

Data Availability Statement

Conflicts of Interest

References

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Association of Chronic Central Serous Chorioretinopathy with Subclinical Cushing’s Syndrome

Abstract

Purpose

Observations

Conclusions and Importance

Keywords

1. Introduction

2. Case report

3. Discussion

4. Conclusion

Patient consent

Acknowledgments and Disclosures

References

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Adrenalectomy in ectopic Cushing’s syndrome: A retrospective cohort study from a tertiary care centre

Abstract

1 INTRODUCTION