Adrenocortical cell lines

Therapeutic potential of targeting the FLNA-regulated Wee1 kinase in adrenocortical carcinomas

Filamin A (FLNA) is poorly expressed in adrenocortical carcinomas (ACC) compared to adenomas (ACA). Its presence is associated to a less aggressive tumour behaviour, potentially due to its role in negatively regulating IGF1R signalling. Upregulation of G2/M Wee1 kinase was shown in FLNA-deficient mouse neural progenitor cells, and it has been reported in several tumours. This study explored Wee1 expression in ACC and its regulation by FLNA, the effects of Wee1 inhibitor AZD1775, and the impact of FLNA on its efficacy in ACC cell lines and primary cells. Analysis of FLNA and Wee1 proteins revealed elevated Wee1 and reduced FLNA in ACC compared to normal adrenal gland. FLNA knockdown increased Wee1 protein in NCI-H295R, MUC-1, and in primary ACC cells. Higher p-CDK1 and cyclin B1 were shown in FLNA-silenced MUC-1, while decreased Wee1, p-CDK1 and cyclin B1 resulted after FLNA overexpression. Wee1 reduction was reverted by lactacystin treatment and FLNA transfection increased p-Wee1 (Ser123), suggesting FLNA's role in targeting Wee1 for degradation. AZD1775 dose-dependently reduced proliferation and viability in ACC cell lines and primary cultures, and it triggered MUC-1 cell death. Similar effects were induced by Wee1 silencing. FLNA depletion augmented AZD1775's efficacy in reducing proliferation and potentiating apoptosis in MUC-1 and primary cells. In conclusion, we demonstrated that FLNA regulates Wee1 expression by promoting its degradation, suggesting that low FLNA typical of ACC leads to increased Wee1 with consequent cancer cells growth. It proposes Wee1 inhibition as a new potential therapeutic approach for ACC, particularly for those lacking FLNA.

Effect of Essential Oil Components on the Activity of Steroidogenic Cytochrome P450

Endocrine-disrupting chemicals (EDCs) may impact the development of prostate cancer (PCa) by altering the steroid metabolism. Although their exact mechanism of action in controlling tumor growth is not known, EDCs may inhibit steroidogenic enzymes such as CYP17A1 or CYP19A1 which are involved in the production of androgens or estrogens. High levels of circulating androgens are linked to PCa in men and Polycystic Ovary Syndrome (PCOS) in women. Essential oils or their metabolites, like lavender oil and tea tree oil, have been reported to act as potential EDCs and contribute towards sex steroid imbalance in cases of prepubertal gynecomastia in boys and premature thelarche in girls due to the exposure to lavender-based fragrances. We screened a range of EO components to determine their effects on CYP17A1 and CYP19A1. Computational docking was performed to predict the binding of essential oils with CYP17A1 and CYP19A1. Functional assays were performed using the radiolabeled substrates or Liquid Chromatography-High-Resolution Mass Spectrometry and cell viability assays were carried out in LNCaP cells. Many of the tested compounds bind close to the active site of CYP17A1, and (+)-Cedrol had the best binding with CYP17A1 and CYP19A1. Eucalyptol, Dihydro-β-Ionone, and (-)-α-pinene showed 20% to 40% inhibition of dehydroepiandrosterone production; and some compounds also effected CYP19A1. Extensive use of these essential oils in various beauty and hygiene products is common, but only limited knowledge about their potential detrimental side effects exists. Our results suggest that prolonged exposure to some of these essential oils may result in steroid imbalances. On the other hand, due to their effect on lowering androgen output and ability to bind at the active site of steroidogenic cytochrome P450s, these compounds may provide design ideas for novel compounds against hyperandrogenic disorders such as PCa and PCOS.

Orexin-A/OX1R is involved in regulation of autophagy to promote cortisol secretion in adrenocortical cell

BACKGROUND

Hypercortisolism has emerged as a prominent clinical condition worldwide caused by biochemical cortisol excess in patients, and optimization treatment is needed urgently in the clinic. Previously, we observed that orexin-A/orexin type 1 receptor (OX1R) promoted cell proliferation, inhibited apoptosis, and increased cortisol release in adrenocortical cells. However, the functions of orexin-A/OX1R on autophagy and its molecular mechanism are not known.

METHODS

Transmission electron microscopy and confocal microscope were performed to detect autophagosomes. Western blot were performed to detect autophagy proteins. The cortisol concentration was assessed with an ELISA.

FINDINGS

Our data demonstrated that orexin-A/OX1R activated the mammalian target of rapamycin/p70 ribosomal protein S6 kinase-1 pathway, thereby inhibiting autophagy in H295R cells and Y-1 cells. Furthermore, the orexin-A/OX1R-mediated suppression of autophagy played a crucial role in cortisol secretion. Mechanistically, the expression of 3β-hydroxysteroid dehydrogenase/isomerase, the rate-limiting enzyme in cortisol synthesis, was increased with autophagy inhibition mediated by orexin-A/OX1R.

INTERPRETATION

This study provided the evidence that orexin-A/OX1R participated in modulating mTOR/p70S6K1/autophagy signaling pathway to promote cortisol secretion in adrenocortical cell. The findings suggest the mechanistic basis for disorders of cortisol secretion, providing the potential therapeutic targets for hypercortisolism treatment. FUND: This work was supported by National Natural Science Foundation of China (32170603, 31871286), the Doctoral Start-up Foundation of Liaoning Province (20180540008, 2019-BS-298), the Natural Science Foundation of Liaoning Province (2019-ZD-0779), and Shenyang Science and Technology Plan Fund Projects (21-173-9-28).

RGS proteins and cardiovascular Angiotensin II Signaling: Novel opportunities for therapeutic targeting

Angiotensin II (AngII), as an octapeptide hormone normally ionized at physiological pH, cannot cross cell membranes and thus, relies on, two (mainly) G protein-coupled receptor (GPCR) types, AT1R and AT2R, to exert its intracellular effects in various organ systems including the cardiovascular one. Although a lot remains to be elucidated about the signaling of the AT2R, AT1R signaling is known to be remarkably versatile, mobilizing a variety of G protein-dependent and independent signal transduction pathways inside cells to produce a biological outcome. Cardiac AT1R signaling leads to hypertrophy, adverse remodeling, fibrosis, while vascular AT1R signaling raises blood pressure via vasoconstriction, but also elicits hypertrophic, vascular growth/proliferation, and pathological remodeling sets of events. In addition, adrenal AT1R is the major physiological stimulus (alongside hyperkalemia) for secretion of aldosterone, a mineralocorticoid hormone that contributes to hypertension, electrolyte abnormalities, and to pathological remodeling of the failing heart. Regulator of G protein Signaling (RGS) proteins, discovered about 25 years ago as GTPase-activating proteins (GAPs) for the Gα subunits of heterotrimeric G proteins, play a central role in silencing G protein signaling from a plethora of GPCRs, including the AngII receptors. Given the importance of AngII and its receptors, but also of several RGS proteins, in cardiovascular homeostasis, the physiological and pathological significance of RGS protein-mediated modulation of cardiovascular AngII signaling comes as no surprise. In the present review, we provide an overview of the current literature on the involvement of RGS proteins in cardiovascular AngII signaling, by discussing their roles in cardiac (cardiomyocyte and cardiofibroblast), vascular (smooth muscle and endothelial cell), and adrenal (medulla and cortex) AngII signaling, separately. Along the way, we also highlight the therapeutic potential of enhancement of, or, in some cases, inhibition of each RGS protein involved in AngII signaling in each one of these cell types.

A 3D adrenocortical carcinoma tumor platform for preclinical modeling of drug response and matrix metalloproteinase activity

Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin α. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies.

A 3D adrenocortical carcinoma tumor platform for preclinical modeling of drug response and matrix metalloproteinase activity

Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin alpha. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies.

Angiotensin II-dependent aldosterone production in the adrenal cortex

The adrenal cortex is responsible for production of adrenal steroid hormones and is anatomically divided into three distinct zones: zona glomerulosa secreting mineralocorticoids (mainly aldosterone), zona fasciculata secreting glucocorticoids (cortisol), and zona reticularis producing androgens. Importantly, due to their high lipophilicity, no adrenal steroid hormone (including aldosterone) is stored in vesicles but rather gets synthesized and secreted instantly upon cell stimulation with specific stimuli. Aldosterone is the most potent mineralocorticoid hormone produced from the adrenal cortex in response to either angiotensin II (AngII) or elevated K+ levels in the blood (hyperkalemia). AngII, being a peptide, cannot cross cell membranes and thus, uses two distinct G protein-coupled receptor (GPCR) types, AngII type 1 receptor (AT1R) and AT2R to exert its effects inside cells. In zona glomerulosa cells, AT1R activation by AngII results in aldosterone synthesis and secretion via two main pathways: (a) Gq/11 proteins that activate phospholipase C ultimately raising intracellular free calcium concentration; and (b) βarrestin1 and -2 (also known as Arrestin-2 and -3, respectively) that elicit sustained extracellular signal-regulated kinase (ERK) activation. Both pathways induce upregulation and acute activation of StAR (steroidogenic acute regulatory) protein, the enzyme that catalyzes the rate-limiting step in aldosterone biosynthesis. This chapter describes these two salient pathways underlying AT1R-induced aldosterone production in zona glomerulosa cells. We also highlight some pharmacologically important notions pertaining to the efficacy of the currently available AT1R antagonists, also known as angiotensin receptor blockers (ARBs) or sartans at suppressing both pathways, i.e., their inverse agonism efficacy at G proteins and βarrestins.

Non-steroidal CYP17A1 Inhibitors: Discovery and Assessment

CYP17A1 is an enzyme that plays a major role in steroidogenesis and is critically involved in the biosynthesis of steroid hormones. Therefore, it remains an attractive target in several serious hormone-dependent cancer diseases, such as prostate cancer and breast cancer. The medicinal chemistry community has been committed to the discovery and development of CYP17A1 inhibitors for many years, particularly for the treatment of castration-resistant prostate cancer. The current Perspective reflects upon the discovery and evaluation of non-steroidal CYP17A1 inhibitors from a medicinal chemistry angle. Emphasis is placed on the structural aspects of the target, key learnings from the presented chemotypes, and design guidelines for future inhibitors.

New insights into signal transduction pathways in adrenal steroidogenesis: role of mitochondrial fusion, lipid mediators, and MAPK phosphatases

Hormone-receptor signal transduction has been extensively studied in adrenal gland. Zona glomerulosa and fasciculata cells are responsible for glucocorticoid and mineralocorticoid synthesis by adrenocorticotropin (ACTH) and angiotensin II (Ang II) stimulation, respectively. Since the rate-limiting step in steroidogenesis occurs in the mitochondria, these organelles are key players in the process. The maintenance of functional mitochondria depends on mitochondrial dynamics, which involves at least two opposite events, i.e., mitochondrial fusion and fission. This review presents state-of-the-art data on the role of mitochondrial fusion proteins, such as mitofusin 2 (Mfn2) and optic atrophy 1 (OPA1), in Ang II-stimulated steroidogenesis in adrenocortical cells. Both proteins are upregulated by Ang II, and Mfn2 is strictly necessary for adrenal steroid synthesis. The signaling cascades of steroidogenic hormones involve an increase in several lipidic metabolites such as arachidonic acid (AA). In turn, AA metabolization renders several eicosanoids released to the extracellular medium able to bind membrane receptors. This report discusses OXER1, an oxoeicosanoid receptor which has recently arisen as a novel participant in adrenocortical hormone-stimulated steroidogenesis through its activation by AA-derived 5-oxo-ETE. This work also intends to broaden knowledge of phospho/dephosphorylation relevance in adrenocortical cells, particularly MAP kinase phosphatases (MKPs) role in steroidogenesis. At least three MKPs participate in steroid production and processes such as the cellular cycle, either directly or by means of MAP kinase regulation. To sum up, this review discusses the emerging role of mitochondrial fusion proteins, OXER1 and MKPs in the regulation of steroid synthesis in adrenal cortex cells.

Preclinical Evidence of Progesterone as a New Pharmacological Strategy in Human Adrenocortical Carcinoma Cell Lines

BACKGROUND

Adrenocortical cancer (ACC) is a rare malignancy with a dismal prognosis. The treatment includes mitotane and EDP chemotherapy (etoposide, doxorubicin, and cisplatin). However, new therapeutic approaches for advanced ACC are needed, particularly targeting the metastatic process. Here, we deepen the role of progesterone as a new potential drug for ACC, in line with its antitumoral effect in other cancers.

METHODS

NCI-H295R, MUC-1, and TVBF-7 cell lines were used and xenografted in zebrafish embryos. Migration and invasion were studied using transwell assays, and MMP2 activity was studied using zymography. Apoptosis and cell cycle were analyzed by flow cytometry.

RESULTS

Progesterone significantly reduced xenograft tumor area and metastases formation in embryos injected with metastatic lines, MUC-1 and TVBF-7. These results were confirmed in vitro, where the reduction of invasion was mediated, at least in part, by the decrease in MMP2 levels. Progesterone exerted a long-lasting effect in metastatic cells. Progesterone caused apoptosis in NCI-H295R and MUC-1, inducing changes in the cell-cycle distribution, while autophagy was predominantly activated in TVBF-7 cells.

CONCLUSION

Our results give support to the role of progesterone in ACC. The involvement of its analog (megestrol acetate) in reducing ACC progression in ACC patients undergoing EDP-M therapy is now under investigation in the PESETA phase II clinical study.

History of Adrenal Research: From Ancient Anatomy to Contemporary Molecular Biology

The adrenal is a small, anatomically unimposing structure that escaped scientific notice until 1564 and whose existence was doubted by many until the 18th century. Adrenal functions were inferred from the adrenal insufficiency syndrome described by Addison and from the obesity and virilization that accompanied many adrenal malignancies, but early physiologists sometimes confused the roles of the cortex and medulla. Medullary epinephrine was the first hormone to be isolated (in 1901), and numerous cortical steroids were isolated between 1930 and 1949. The treatment of arthritis, Addison's disease, and congenital adrenal hyperplasia (CAH) with cortisone in the 1950s revolutionized clinical endocrinology and steroid research. Cases of CAH had been reported in the 19th century, but a defect in 21-hydroxylation in CAH was not identified until 1957. Other forms of CAH, including deficiencies of 3β-hydroxysteroid dehydrogenase, 11β-hydroxylase, and 17α-hydroxylase were defined hormonally in the 1960s. Cytochrome P450 enzymes were described in 1962-1964, and steroid 21-hydroxylation was the first biosynthetic activity associated with a P450. Understanding of the genetic and biochemical bases of these disorders advanced rapidly from 1984 to 2004. The cloning of genes for steroidogenic enzymes and related factors revealed many mutations causing known diseases and facilitated the discovery of new disorders. Genetics and cell biology have replaced steroid chemistry as the key disciplines for understanding and teaching steroidogenesis and its disorders.

Adrenal G Protein-Coupled Receptors and the Failing Heart: A Long-distance, Yet Intimate Affair

Systolic heart failure (HF) is a chronic clinical syndrome characterized by the reduction in cardiac function and still remains the disease with the highest mortality worldwide. Despite considerable advances in pharmacological treatment, HF represents a severe clinical and social burden. Chronic human HF is characterized by several important neurohormonal perturbations, emanating from both the autonomic nervous system and the adrenal glands. Circulating catecholamines (norepinephrine and epinephrine) and aldosterone elevations are among the salient alterations that confer significant hormonal burden on the already compromised function of the failing heart. This is why sympatholytic treatments (such as β-blockers) and renin-angiotensin system inhibitors or mineralocorticoid receptor antagonists, which block the effects of angiotensin II (AngII) and aldosterone on the failing heart, are part of the mainstay HF pharmacotherapy presently. The adrenal gland plays an important role in the modulation of cardiac neurohormonal stress because it is the source of almost all aldosterone, of all epinephrine, and of a significant amount of norepinephrine reaching the failing myocardium from the blood circulation. Synthesis and release of these hormones in the adrenals is tightly regulated by adrenal G protein-coupled receptors (GPCRs), such as adrenergic receptors and AngII receptors. In this review, we discuss important aspects of adrenal GPCR signaling and regulation, as they pertain to modulation of cardiac function in the context of chronic HF, by focusing on the 2 best studied adrenal GPCR types in that context, adrenergic receptors and AngII receptors (AT 1 Rs). Particular emphasis is given to findings from the past decade and a half that highlight the emerging roles of the GPCR-kinases and the β-arrestins in the adrenals, 2 protein families that regulate the signaling and functioning of GPCRs in all tissues, including the myocardium and the adrenal gland.

Advances in adrenocortical carcinoma pharmacotherapy: what is the current state of the art?

INTRODUCTION

Surgery, followed or not by adjuvant mitotane, is the current mainstay of therapy for patients with early-stage adrenocortical carcinoma (ACC). Mitotane, either alone or in association with EDP (Etoposide-Doxorubicin-Cisplatin) combination chemotherapy, is the standard approach for patients with metastatic ACC.

AREAS COVERED

The activity of newer cytotoxic drugs, radioligands, targeted therapies and immunotherapy, both in preclinical and in clinical studies, will be reviewed in this paper.

EXPERT OPINION

ADIUVO trial revealed that the administration of adjuvant mitotane is not advantageous in patients with good prognosis. Future strategies are to intensify efforts in adjuvant setting in patients with high risk of relapse. In patients with advanced/metastatic disease, modern targeted therapies have shown significant cytotoxicity in preclinical studies, however, studies in ACC patients reported disappointing results so far. The absence of targeted agents specifically inhibiting the major molecular pathways of ACC growth is the main cause of the failure of these drugs. Since ACC is often antigenic but poorly immunogenic, the results of immunotherapy trials appeared inferior to those achieved in the management of patients with other malignancies. Radioligand therapy may also be a promising approach. Combination of chemotherapy plus immunotherapy could be interesting to be tested in the future.

Human adrenocortical carcinoma cell line (NCI-H295R): An in vitro screening model for the assessment of endocrine disruptors' actions on steroidogenesis with an emphasis on cell ultrastructural features

Cell lines as an in vitro model for xenobiotic screening and toxicity studies provide a very important tool in the field of scientific research at the level of molecular pathways and gene expression. Good cell culture practice and intracellular characterization, as well as physiological properties of the cell line are of critical importance for in vitro reproductive toxicity testing of various endocrine-disrupting chemicals. The NCI-H295R, human adrenocarcinoma cell line, is the most widely used in vitro cellular system to study the human adrenal steroidogenic pathway at the level of hormone production and gene expression, as it expresses genes that encode for all the key enzymes for steroidogenesis. In this review, we aim to highlight the information considering the origin, development, physiological and ultrastructural characteristics of the NCI-H295R cell line. The review also creates a broad overview of the cell line usage in various range of studies related to the steroidogenesis issues. To our best knowledge, the paper provides the first report of quantitative data (ex novo) from stereological estimates of component (volume, surface) densities of nuclei, mitochondria, and lipid droplets of the NCI-H295R cells. Such ultrastructural measurements can be valuable in the assessment of underlying mechanisms of changes in the cell steroid hormone production induced by the action of diverse endocrine disruptors. Thus, they can significantly contribute to complexity of structure-function relationships in association with steroidogenesis.

The role of lipid second messengers in aldosterone synthesis and secretion

Second messengers are small rapidly diffusing molecules or ions that relay signals between receptors and effector proteins to produce a physiological effect. Lipid messengers constitute one of the four major classes of second messengers. The hydrolysis of two main classes of lipids, glycerophospholipids and sphingolipids, generate parallel profiles of lipid second messengers: phosphatidic acid (PA), diacylglycerol (DAG), and lysophosphatidic acid versus ceramide, ceramide-1-phosphate, sphingosine, and sphingosine-1-phosphate, respectively. In this review, we examine the mechanisms by which these lipid second messengers modulate aldosterone production at multiple levels. Aldosterone is a mineralocorticoid hormone responsible for maintaining fluid volume, electrolyte balance, and blood pressure homeostasis. Primary aldosteronism is a frequent endocrine cause of secondary hypertension. A thorough understanding of the signaling events regulating aldosterone biosynthesis may lead to the identification of novel therapeutic targets. The cumulative evidence in this literature emphasizes the critical roles of PA, DAG, and sphingolipid metabolites in aldosterone synthesis and secretion. However, it also highlights the gaps in our knowledge, such as the preference for phospholipase D-generated PA or DAG, as well as the need for further investigation to elucidate the precise mechanisms by which these lipid second messengers regulate optimal aldosterone production.

Ribociclib Cytotoxicity Alone or Combined With Progesterone and/or Mitotane in in Vitro Adrenocortical Carcinoma Cells

Mitotane is the only approved drug for treating adrenocortical carcinoma (ACC). The regimen added to mitotane is chemotherapy with etoposide, doxorubicin, and cisplatin. This pharmacological approach, however, has a limited efficacy and significant toxicity. Target-therapy agents represent a new promising approach to cancer therapy. Among these, a preeminent role is played by agents that interfere with cell-cycle progression, such as CDK4/6-inhibitors. Here, we investigate whether ribociclib could induce a cytotoxic effect both in ACC cell line and patient-derived primary cell cultures, alone or in combined settings. Cell viability was determined by 3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H-tetrazolium bromide assay, whereas cell proliferation was evaluated by direct count. Binary combination experiments were performed using Chou and Talalay method. Gene expression was analyzed by quantitative RT-PCR, whereas protein expression was evaluated by immunofluorescence. A double staining assay revealed that ribociclib induced a prevalent apoptotic cell death. Cell-cycle analysis was performed to evaluate the effect of ribociclib treatment on cell-cycle progression in ACC cell models. Our results indicate that ribociclib was cytotoxic and reduced the cell proliferation rate. The effect on cell viability was enhanced when ribociclib was combined with progesterone and/or mitotane. The effect of ribociclib on cell-cycle progression revealed a drug-induced cell accumulation in G2 phase. The positive relationship underlined by our results between ribociclib, progesterone, and mitotane strengthen the clinical potential of this combination.

Novel regulation mechanism of adrenal cortisol and DHEA biosynthesis via the endogen ERAD inhibitor small VCP-interacting protein

Endoplasmic reticulum-associated degradation (ERAD) is a well-characterized mechanism of protein quality control by removal of misfolded or unfolded proteins. The tight regulation of ERAD is critical for protein homeostasis as well as lipid metabolism. Although the mechanism is complex, all ERAD branches converge on p97/VCP, a key protein in the retrotranslocation step. The multifunctionality of p97/VCP relies on its multiple binding partners, one of which is the endogenous ERAD inhibitor, SVIP (small VCP-interacting protein). As SVIP is a promising target for the regulation of ERAD, we aimed to assess its novel physiological roles. We revealed that SVIP is highly expressed in the rat adrenal gland, especially in the cortex region, at a consistently high level during postnatal development, unlike the gradual increase in expression seen in developing nerves. Steroidogenic stimulators caused a decrease in SVIP mRNA expression and increase in SVIP protein degradation in human adrenocortical H295R cells. Interestingly, silencing of SVIP diminished cortisol secretion along with downregulation of steroidogenic enzymes and proteins involved in cholesterol uptake and cholesterol biosynthesis. A certain degree of SVIP overexpression mainly increased the biosynthesis of cortisol as well as DHEA by enhancing the expression of key steroidogenic proteins, whereas exaggerated overexpression led to apoptosis, phosphorylation of eIF2α, and diminished adrenal steroid hormone biosynthesis. In conclusion, SVIP is a novel regulator of adrenal cortisol and DHEA biosynthesis, suggesting that alterations in SVIP expression levels may be involved in the deregulation of steroidogenic stimulator signaling and abnormal adrenal hormone secretion.

Cardiovascular angiotensin II type 1 receptor biased signaling: Focus on non-Gq-, non-βarrestin-dependent signaling

The physiological and pathophysiological roles of the angiotensin II type 1 (AT1) receptor, a G protein-coupled receptor ubiquitously expressed throughout the cardiovascular system, have been the focus of intense investigations for decades. The success of angiotensin converting enzyme inhibitors (ACEIs) and of angiotensin receptor blockers (ARBs), which are AT1R-selective antagonists/inverse agonists, in the treatment of heart disease is a testament to the importance of this receptor for cardiovascular homeostasis. Given the pleiotropic signaling of the cardiovascular AT1R and, in an effort to develop yet better drugs for heart disease, the concept of biased signaling has been exploited to design and develop biased AT1R ligands that selectively activate β-arrestin transduction pathways over Gq protein-dependent pathways. However, by focusing solely on Gq or β-arrestins, studies on AT1R "biased" signaling & agonism tend to largely ignore other non-Gq-, non β-arrestin-dependent signaling modalities the very versatile AT1R employs in cardiovascular tissues, including two very important types of signal transducers/regulators: other G protein types (e.g., Gi/o, G12/13) & the Regulator of G protein Signaling (RGS) proteins. In this review, we provide a brief overview of the current state of cardiovascular AT1R biased signaling field with a special focus on the non-Gq-, non β-arrestin-dependent signaling avenues of this receptor in the cardiovascular system, which usually get left out of the conversation of "biased" AT1R signal transduction.

Molecular Mechanisms of Mitotane Action in Adrenocortical Cancer Based on In Vitro Studies

Simple Summary

Mitotane is the only approved drug for the treatment of advanced adrenocortical carcinoma and for postoperative adjuvant therapy. It is known that mitotane destroys the adrenal cortex impairing steroidogenesis, although its exact molecular mechanism is still unclear. However, confounding factors affecting in vitro experiments could reduce the relevance of the studies. In this review, we explore in vitro studies on mitotane effects, highlighting how different experimental conditions might contribute to the controversial findings. On this basis, it may be necessary to re-evaluate the experiments taking into account their potential confounding factors such as cell strains, culture serum, lipoprotein concentration, and culture passages, which could hide important molecular results. As a consequence, the identification of novel pharmacological molecular pathways might be used in the future to implement personalized therapy, maximizing the benefit of mitotane treatment while minimizing its toxicity.

Abstract

Mitotane is the only approved drug for the treatment of advanced adrenocortical carcinoma and is increasingly used for postoperative adjuvant therapy. Mitotane action involves the deregulation of cytochromes P450 enzymes, depolarization of mitochondrial membranes, and accumulation of free cholesterol, leading to cell death. Although it is known that mitotane destroys the adrenal cortex and impairs steroidogenesis, its exact mechanism of action is still unclear. The most used cell models are H295-derived cell strains and SW13 cell lines. The diverging results obtained in presumably identical cell lines highlight the need for a stable in vitro model and/or a standard methodology to perform experiments on H295 strains. The presence of several enzymatic targets responsive to mitotane in mitochondria and mitochondria-associated membranes causes progressive alteration in mitochondrial structure when cells were exposed to mitotane. Confounding factors of culture affecting in vitro experiments could reduce the significance of any molecular mechanism identified in vitro. To ensure experimental reproducibility, particular care should be taken in the choice of culture conditions: aspects such as cell strains, culture serum, lipoproteins concentration, and culture passages should be carefully considered and explicated in the presentation of results. We aimed to review in vitro studies on mitotane effects, highlighting how different experimental conditions might contribute to the controversial findings. If the concerns pointed out in this review will be overcome, the new insights into mitotane mechanism of action observed in-vitro could allow the identification of novel pharmacological molecular pathways to be used to implement personalized therapy.

Transcriptomic Response Dynamics of Human Primary and Immortalized Adrenocortical Cells to Steroidogenic Stimuli

Adrenal steroid hormone production is a dynamic process stimulated by adrenocorticotropic hormone (ACTH) and angiotensin II (AngII). These ligands initialize a rapid and robust gene expression response required for steroidogenesis. Here, we compare the predominant human immortalized cell line model, H295R cell, with primary cultures of adult adrenocortical cells derived from human kidney donors. We performed temporally resolved RNA-seq on primary cells stimulated with either ACTH or AngII at multiple time points. The magnitude of the expression dynamics elicited by ACTH was greater than AngII in primary cells. This is likely due to the larger population of adrenocortical cells that are responsive to ACTH. The dynamics of stimulus-induced expression in H295R cells are mostly recapitulated in primary cells. However, there are some expression responses in primary cells absent in H295R cells. These data are a resource for the endocrine community and will help researchers determine whether H295R is an appropriate model for the specific aspect of steroidogenesis that they are studying.

Assessment of the Effective Impact of Bisphenols on Mitochondrial Activity, Viability and Steroidogenesis in a Dose-Dependency in Human Adrenocortical Carcinoma Cells

In recent years, bisphenol analogues such as bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) have come to replace bisphenol A (BPA) in food packaging and food containers, since BPA has been shown to leach into food and water, causing numerous negative health effects. Although much information on the endocrine activity of BPA is available, a proper human hazard assessment of analogues that are believed to have a less harmful toxicity profile is lacking. The aim of our in vitro study was to assess the potential effect of bisphenol B, F, and S on the biosynthesis of steroid hormones in human H295R adrenocortical carcinoma cells, using the enzyme-linked immunosorbent assay. In addition, we evaluated mitochondrial activity using the MTT test and viability using triple assay. Adrenocortical carcinoma cells were cultivated for 24 h in the presence of bisphenol B, F, or S (0.1, 0.5, 1, 10, 25, 50, 75, 100 μM). We demonstrated that BPB, BPF, and BPS could affect progesterone and testosterone secretion, as well as affect cell mitochondrial, lysosomal, and metabolic activity, as well as plasma membrane integrity, but considerably more detailed and systematic research is required for a better understanding of risks associated with the effects of bisphenols on steroidogenesis.

Adrenal angiotensin II type 1 receptor biased signaling: The case for "biased" inverse agonism for effective aldosterone suppression

Angiotensin II (AngII) uses two distinct G protein-coupled receptor (GPCR) types, AT1R and AT2R, to exert a plethora of physiologic effects in the body and to significantly affect cardiovascular homeostasis. Although not much is known about the signaling of the AT2R, AT1R signaling is known to be quite pleiotropic, mobilizing a variety of signal transducers inside cells to produce a biological outcome. When the outcome in question is aldosterone production from the adrenal cortex, the main transducers activated specifically by the adrenocortical AT1R to signal toward that cellular effect are the Gq/11 protein alpha subunits and the β-arrestins (also known as Arrestin-2 and -3). The existence of various downstream pathways the AT1R signal can travel down on has led to the ever-expanding filed of GPCR pharmacology termed "biased" signaling, which refers to a ligand preferentially activating one signaling pathway over others downstream of the same receptor in the same cell. However, "biased" signaling or "biased" agonism is therapeutically desirable only when the downstream pathways lead to different or opposite cellular outcomes, so the pathway promoting the beneficial effect can be selectively activated over the pathway that leads to detrimental consequences. In the case of the adrenal AT1R, both Gq/11 proteins and β-arrestins mediate signaling to the same end-result: aldosterone synthesis and secretion. Therefore, both pathways need to remain inactive in the adrenal cortex to fully suppress the production of aldosterone, which is one of the culprit hormones elevated in chronic heart failure, hypertension, and various other cardiovascular diseases. Variations in the effectiveness of the AT1R antagonists, which constitute the angiotensin receptor blocker (ARB) class of drugs (also known as sartans), at the relative blockade of these two pathways downstream of the adrenal AT1R opens the door to the flip term "biased" inverse agonism at the AT1R. ARBs that are unbiased and equipotent inverse agonists for both G proteins and β-arrestins at this receptor, like candesartan and valsartan, are the most preferred agents with the best efficacy at reducing circulating aldosterone, thereby ameliorating heart failure. In the present review, the biased signaling of the adrenal AT1R, particularly in relation to aldosterone production, is examined and the term "biased" inverse agonism at the AT1R is introduced and explained, as a means of pharmacological categorization of the various agents within the ARB drug class.

Adrenal cortex development and related disorders leading to adrenal insufficiency

The adult human adrenal cortex produces steroid hormones that are crucial for life, supporting immune response, glucose homeostasis, salt balance and sexual maturation. It consists of three histologically distinct and functionally specialized zones. The fetal adrenal forms from mesodermal material and produces predominantly adrenal C₁₉ steroids from its fetal zone, which involutes after birth. Transition to the adult cortex occurs immediately after birth for the formation of the zona glomerulosa and fasciculata for aldosterone and cortisol production and continues through infancy until the zona reticularis for adrenal androgen production is formed with adrenarche. The development of this indispensable organ is complex and not fully understood. This article gives an overview of recent knowledge gained of adrenal biology from two perspectives: one, from basic science studying adrenal development, zonation and homeostasis; and two, from adrenal disorders identified in persons manifesting with various isolated or syndromic forms of primary adrenal insufficiency.

Comparative proteomic analysis to identify the novel target gene of angiotensin II in adrenocortical H295R cells

Angiotensin II (Ang II) is a well-known peptide that maintains the balance of electrolytes in the higher vertebrates. Ang II stimulation in the adrenal gland induces the synthesis of mineralocorticoids, mainly aldosterone, through the up-regulation of aldosterone synthase (CYP11B2) gene expression. Additionally, it has been reported that Ang II activates multiple signaling pathways such as mitogen-activated protein kinase (MAPK) and Ca²⁺ signaling. Although Ang II has various effects on the cellular signaling in the adrenal cells, its biological significance, except for the aldosterone synthesis, is still unclear. In this study, we attempted to search the novel target gene(s) of Ang II in the human adrenal H295R cells using a proteomic approach combined with stable isotopic labeling using amino acid in cell culture (SILAC). Interestingly, we found that Ang II stimulation elevated the expression of phosphofructokinase type platelet (PFKP) in both protein and mRNA levels. Moreover, transactivation of PFKP by Ang II was dependent on extracellular-signal-regulated kinase (ERK) 1/2 activation. Finally, we observed that Ang II treatment facilitated glucose uptake in the H295R cells. Taken together, we here identified PFKP as a novel target gene of Ang II, indicating that Ang II not only stimulates steroidogenesis but also affects glucose metabolism.

Cytotoxic Effect of Progesterone, Tamoxifen and Their Combination in Experimental Cell Models of Human Adrenocortical Cancer

Progesterone (Pg) and estrogen (E) receptors (PgRs and ERs) are expressed in normal and neoplastic adrenal cortex, but their role is not fully understood. In literature, Pg demonstrated cytotoxic activity on AdrenoCortical Carcinoma (ACC) cells, while tamoxifen is cytotoxic in NCI-H295R cells. Here, we demonstrated that in ACC cell models, ERs were expressed in NCI-H295R cells with a prevalence of ER-β over the ER-α.Metastasis-derived MUC-1 and ACC115m cells displayed a very weak ER-α/β signal, while PgR cells were expressed, although at low level. Accordingly, these latter were resistant to the SERM tamoxifen and scarcely sensitive to Pg, as we observed a lower potency compared to NCI-H295R cells in cytotoxicity (IC50: MUC-1 cells: 67.58 µM (95%CI: 63.22-73.04), ACC115m cells: 51.76 µM (95%CI: 46.45-57.67) and cell proliferation rate. Exposure of NCI-H295R cells to tamoxifen induced cytotoxicity (IC50: 5.43 µM (95%CI: 5.18-5.69 µM) mainly involving ER-β, as their nuclear localization increased after tamoxifen: Δ A.U. treated vs untreated: 12 h: +27.04% (p < 0.01); 24 h: +36.46% (p < 0.0001). This effect involved the SF-1 protein reduction: Pg: -36.34 ± 9.26%; tamoxifen: -46.25 ± 15.68% (p < 0.01). Finally, in a cohort of 36 ACC samples, immunohistochemistry showed undetectable/low level of ERs, while PgR demonstrated a higher expression. In conclusion, ACC experimental cell models expressed PgR and low levels of ER in line with data obtained in patient tissues, thus limiting the possibility of a clinical approach targeting ER. Interestingly, Pg exerted cytotoxicity also in metastatic ACC cells, although with low potency.

The SARS-CoV-2 receptor and other key components of the Renin-Angiotensin-Aldosterone System related to COVID-19 are expressed in enterocytes in larval zebrafish

People with underlying conditions, including hypertension, obesity, and diabetes, are especially susceptible to negative outcomes after infection with coronavirus SARS-CoV-2, which causes COVID-19. Hypertension and respiratory inflammation are exacerbated by the Renin-Angiotensin-Aldosterone System (RAAS), which normally protects from rapidly dropping blood pressure via Angiotensin II (Ang II) produced by the enzyme Ace. The Ace paralog Ace2 degrades Ang II, counteracting its chronic effects, and serves as the SARS-CoV-2 receptor. Ace, the coronavirus, and COVID-19 comorbidities all regulate Ace2, but we do not yet understand how. To exploit zebrafish (Danio rerio) to help understand the relationship of the RAAS to COVID-19, we must identify zebrafish orthologs and co-orthologs of human RAAS genes and understand their expression patterns. To achieve these goals, we conducted genomic and phylogenetic analyses and investigated single cell transcriptomes. Results showed that most human RAAS genes have one or more zebrafish orthologs or co-orthologs. Results identified a specific type of enterocyte as the specific site of expression of zebrafish orthologs of key RAAS components, including Ace, Ace2, Slc6a19 (SARS-CoV-2 co-receptor), and the Angiotensin-related peptide cleaving enzymes Anpep (receptor for the common cold coronavirus HCoV-229E), and Dpp4 (receptor for the Middle East Respiratory Syndrome virus, MERS-CoV). Results identified specific vascular cell subtypes expressing Ang II receptors, apelin, and apelin receptor genes. These results identify genes and cell types to exploit zebrafish as a disease model for understanding mechanisms of COVID-19.

Primary Cultures and Cell Lines for In Vitro Modeling of the Human Adrenal Cortex

The human adrenal cortex is a complex endocrine organ that produces mineralocorticoids, glucocorticoids and androgens. These steroids are produced in distinct cell types located within the glomerulosa, fasciculata and reticularis of the adrenal cortex. Abnormal adrenal steroidogenesis leads to a variety of diseases that can cause hypertension, metabolic syndrome, infertility and premature adrenarche. The adrenal cortex can also develop steroid-producing adenomas and rarely adrenocortical carcinomas. In vitro cell culture models provide important tools to study molecular and cellular mechanisms controlling both the physiologic and pathologic conditions of the adrenal cortex. In addition, the presence of multiple steroid-metabolizing enzymes within adrenal cells makes it a model for defining possible endocrine disruptors that might block these enzymes. The regulation and dysregulation of human adrenal steroid production and cell division/tumor growth can be studied using freshly isolated cells but this requires access to human adrenal glands, which are not available to most investigators. Immortalized human adrenocortical cell lines have proven to be of considerable value in studying the molecular and biochemical mechanisms controlling adrenal steroidogenesis and tumorigenesis. Current human adrenal cell lines include the original NCI-H295 and its substrains: H295A, H295R, HAC13, HAC15, HAC50 and H295RA as well as the recently established MUC-1, CU-ACC1 and CU-ACC2. The current review will discuss the use of primary cultures of fetal and adult adrenal cells as well as adrenocortical cell lines as in vitro models for the study of human adrenal physiology and pathophysiology.

Plant Natural Compounds in the Treatment of Adrenocortical Tumors

Plant natural products are a plethora of diverse and complex molecules produced by the plant secondary metabolism. Among these, many can reserve beneficial or curative properties when employed to treat human diseases. Even in cancer, they can be successfully used and indeed numerous phytochemicals exert antineoplastic activity. The most common molecules derived from plants and used in the fight against cancer are polyphenols, i.e., quercetin, genistein, resveratrol, curcumin, etc. Despite valuable data especially in preclinical models on such compounds, few of them are currently used in the medical practice. Also, in adrenocortical tumors (ACT), phytochemicals are scarcely or not at all used. This work summarizes the available research on phytochemicals used against ACT and adrenocortical cancer, a very rare disease with poor prognosis and high metastatic potential, and wants to contribute to stimulate preclinical and clinical research to find new therapeutic strategies among the overabundance of biomolecules produced by the plant kingdom.

In vitro assessment of the impact of nickel on the viability and steroidogenesis in the human adrenocortical carcinoma (NCI-H295R) cell line

Nickel is a ubiquitous environmental pollutant, which has various effects on reproductive endocrinology. In this study, human adrenocortical carcinoma (NCI-H295R) cell line was used as an in vitro biological model to study the effect of nickel chloride (NiCl2) on the viability and steroidogenesis. The cells were exposed to different concentrations (3.90; 7.80; 15.60; 31.20; 62.50; 125; 250 and 500 microM) of NiCl2 and compared with control group (culture medium without NiCl2). The cell viability was measured by the metabolic activity assay. Production of sexual steroid hormones was quantified by enzyme linked immunosorbent assay. Following 48 h culture of the cells in the presence of NiCl2 a dose-dependent depletion of progesterone release was observed even at the lower concentrations. In fact, lower levels of progesterone were detected in groups with higher doses (>/=125 microM) of NiCl2 (P<0.01), which also elicited cytotoxic action. A more prominent decrease in testosterone production (P<0.01) was also noted in comparison to that of progesterone. On the other hand, the release of 17beta-estradiol was substantially increased at low concentrations (3.90 to 62.50 microM) of NiCl2. The cell viability remained relatively unaltered up to 125 microM (P>0.05) and slightly decreased from 250 microM of NiCl2 (P<0.05). Our results indicate endocrine disruptive effect of NiCl2 on the release of progesterone and testosterone in the NCI-H295R cell line. Although no detrimental effect of NiCl2 (</=62.50 microM) could be found on 17beta-estradiol production, its toxicity may reflect at other points of the steroidogenic pathway.

A Targeted Bioinformatics Assessment of Adrenocortical Carcinoma Reveals Prognostic Implications of GABA System Gene Expression

Adrenocortical carcinoma (ACC) is a rare but deadly cancer for which few treatments exist. Here, we have undertaken a targeted bioinformatics study of The Cancer Genome Atlas (TCGA) ACC dataset focusing on the 30 genes encoding the γ-aminobutyric acid (GABA) system—an under-studied, evolutionarily-conserved system that is an emerging potential player in cancer progression. Our analysis identified a subset of ACC patients whose tumors expressed a distinct GABA system transcriptome. Transcript levels of ABAT (encoding a key GABA shunt enzyme), were upregulated in over 40% of tumors, and this correlated with several favorable clinical outcomes including patient survival; while enrichment and ontology analysis implicated two cancer-related biological pathways involved in metastasis and immune response. The phenotype associated with ABAT upregulation revealed a potential metabolic heterogeneity among ACC tumors associated with enhanced mitochondrial metabolism. Furthermore, many GABA_A receptor subunit-encoding transcripts were expressed, including two (GABRB2 and GABRD) prognostic for patient survival. Transcripts encoding GABA_B receptor subunits and GABA transporters were also ubiquitously expressed. The GABA system transcriptome of ACC tumors is largely mirrored in the ACC NCI-H295R cell line, suggesting that this cell line may be appropriate for future functional studies investigating the role of the GABA system in ACC cell growth phenotypes and metabolism.

Range of SHH signaling in adrenal gland is limited by membrane contact to cells with primary cilia

The signaling protein Sonic Hedgehog (SHH) is crucial for the development and function of many vertebrate tissues. It remains largely unclear, however, what defines the range and specificity of pathway activation. The adrenal gland represents a useful model to address this question, where the SHH pathway is activated in a very specific subset of cells lying near the SHH-producing cells, even though there is an abundance of lipoproteins that would allow SHH to travel and signal long-range. We determine that, whereas adrenal cells can secrete SHH on lipoproteins, this form of SHH is inactive due to the presence of cosecreted inhibitors, potentially explaining the absence of long-range signaling. Instead, we find that SHH-producing cells signal at short range via membrane-bound SHH, only to receiving cells with primary cilia. Finally, our data from NCI-H295R adrenocortical carcinoma cells suggest that adrenocortical tumors may evade these regulatory control mechanisms by acquiring the ability to activate SHH target genes in response to TGF-β.

Adropin Stimulates Proliferation and Inhibits Adrenocortical Steroidogenesis in the Human Adrenal Carcinoma (HAC15) Cell Line

Adropin is a multifunctional peptide hormone encoded by the ENHO (energy homeostasis associated) gene. It plays a role in mechanisms related to increased adiposity, insulin resistance, as well as glucose, and lipid metabolism. The low adropin levels are strongly associated with obesity independent insulin resistance. On the other hand, overexpression or exogenous administration of adropin improves glucose homeostasis. The multidirectional, adropin-related effects associated with the regulation of metabolism in humans also appear to be attributable to the effects of this peptide on the activity of various elements of the endocrine system including adrenal cortex. Therefore, the main purpose of the present study was to investigate the effect of adropin on proliferation and secretory activity in the human HAC15 adrenal carcinoma cell line. In this study, we obtained several highly interesting findings. First, GPR19, the main candidate sensitizer of adrenocortical cells to adropin, was expressed in HAC15 cells. Moreover, GPR19 expression was relatively stable and not regulated by ACTH, forskolin, or adropin itself. Our findings also suggest that adropin has the capacity to decrease expression levels of steroidogenic genes such as steroidogenic acute regulatory protein (StAR) and CYP11A1, which then led to a statistically significant inhibition in cortisol and aldosterone biosynthesis and secretion. Based on whole transcriptome study and research involving transforming growth factor (TGF)-β type I receptor kinase inhibitor we demonstrated that attenuation of steroidogenesis caused by adropin is mediated by the TGF-β signaling pathway likely to act through transactivation mechanism. We found that HAC15 cells treated with adropin presented significantly higher proliferation levels than untreated cells. Using specific intracellular inhibitors, we showed that adropin stimulate proliferation via ERK1/2 and AKT dependent signaling pathways. We have also demonstrated that expression of GPR19 is elevated in adrenocortical carcinoma in relation to normal adrenal glands. High level of GPR19 expression in adrenocortical carcinoma may constitute a negative prognostic factor of disease progression.

An intestinal cell type in zebrafish is the nexus for the SARS-CoV-2 receptor and the Renin-Angiotensin-Aldosterone System that contributes to COVID-19 comorbidities

People with underlying conditions, including hypertension, obesity, and diabetes, are especially susceptible to negative outcomes after infection with the coronavirus SARS-CoV-2. These COVID-19 comorbidities are exacerbated by the Renin-Angiotensin-Aldosterone System (RAAS), which normally protects from rapidly dropping blood pressure or dehydration via the peptide Angiotensin II (Ang II) produced by the enzyme Ace. The Ace paralog Ace2 degrades Ang II, thus counteracting its chronic effects. Ace2 is also the SARS-CoV-2 receptor. Ace , the coronavirus, and COVID-19 comorbidities all regulate Ace2 , but we don't yet understand how. To exploit zebrafish ( Danio rerio ) as a disease model to understand mechanisms regulating the RAAS and its relationship to COVID-19 comorbidities, we must first identify zebrafish orthologs and co-orthologs of human RAAS genes, and second, understand where and when these genes are expressed in specific cells in zebrafish development. To achieve these goals, we conducted genomic analyses and investigated single cell transcriptomes. Results showed that most human RAAS genes have an ortholog in zebrafish and some have two or more co-orthologs. Results further identified a specific intestinal cell type in zebrafish larvae as the site of expression for key RAAS components, including Ace, Ace2, the coronavirus co-receptor Slc6a19, and the Angiotensin-related peptide cleaving enzymes Anpep and Enpep. Results also identified specific vascular cell subtypes as expressing Ang II receptors, apelin , and apelin receptor genes. These results identify specific genes and cell types to exploit zebrafish as a disease model for understanding the mechanisms leading to COVID-19 comorbidities.

SUMMARY STATEMENT

Genomic analyses identify zebrafish orthologs of the Renin-Angiotensin-Aldosterone System that contribute to COVID-19 comorbidities and single-cell transcriptomics show that they act in a specialized intestinal cell type.

Effects of fast food packaging plasticizers and their metabolites on steroid hormone synthesis in H295R cells

The health risks of exposure to plasticizers have received widespread attention, however, little is known about the effects of fast food packaging plasticizers on steroid hormone synthesis. In the present study, the types and migration of plasticizers in some commonly used fast-food packaging materials were detected by GC-MS, and the interference effects of these plasticizers and their metabolites on steroid hormone synthesis in the human body were evaluated by the H295R steroidogenesis assay. The GC-MS results showed that the main plasticizer compounds that migrated from fast food packaging into food were di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and bis(2-ethylhexyl) adipate (DEHA). Exposure to these chemicals (100-1000 μM) can significantly reduce the viability of H295R cells in a dose-response manner, and these plasticizers and their metabolites that migrated into oily foods at high temperatures (0.25-25 μM) could significantly increase the E2 level and reduce the T level in H295R cells. According to the qRT-PCR data, 0.25 to 25 μM mono(2-ethylhexyl) phthalate (MEHP) significantly upregulated the expression levels of 17β-HSD1 and CYP19A1, and downregulated those of CYP17A1, CYP11A1 and StAR. The Western blot results were consistent with those of qRT-PCR. In summary, these results indicated that even exposure to low concentrations (≤1 mg/l or 2.5 μM) of these chemicals and their metabolites can cause significant endocrine-disrupting effects.

Nicotine-induced adrenal beta-arrestin1 upregulation mediates tobacco-related hyperaldosteronism leading to cardiac dysfunction

BACKGROUND

Tobacco-related products, containing the highly addictive nicotine together with numerous other harmful toxicants and carcinogens, have been clearly associated with coronary artery disease, heart failure, stroke, and other heart diseases. Among the mechanisms by which nicotine contributes to heart disease is elevation of the renin-angiotensin-aldosterone system (RAAS) activity. Nicotine, and its major metabolite in humans cotinine, have been reported to induce RAAS activation, resulting in aldosterone elevation in smokers. Aldosterone has various direct and indirect adverse cardiac effects. It is produced by the adrenal cortex in response to angiotensin II (AngII) activating AngII type 1 receptors. RAAS activity increases in chronic smokers, causing raised aldosterone levels (nicotine exposure causes the same in rats). AngII receptors exert their cellular effects via either G proteins or the two βarrestins (βarrestin1 and-2).

AIM

Since adrenal ßarrestin1 is essential for adrenal aldosterone production and nicotine/cotinine elevate circulating aldosterone levels in humans, we hypothesized that nicotine activates adrenal ßarrestin1, which contributes to RAAS activation and heart disease development.

METHODS

We studied human adrenocortical zona glomerulosa H295R cells and found that nicotine and cotinine upregulate βarrestin1 mRNA and protein levels, thereby enhancing AngII-dependent aldosterone synthesis and secretion.

RESULTS

In contrast, siRNA-mediated βarrestin1 knockdown reversed the effects of nicotine on AngII-induced aldosterone production in H295R cells. Importantly, nicotine promotes hyperaldosteronism via adrenal βarrestin1, thereby precipitating cardiac dysfunction, also in vivo, since nicotine-exposed experimental rats with adrenal-specific βarrestin1 knockdown display lower circulating aldosterone levels and better cardiac function than nicotine-exposed control animals with normal adrenal βarrestin1 expression.

CONCLUSION

Adrenal βarrestin1 upregulation is one of the mechanisms by which tobacco compounds, like nicotine, promote cardio-toxic hyperaldosteronism in vitro and in vivo. Thus, adrenal βarrestin1 represents a novel therapeutic target for tobacco-related heart disease prevention or mitigation.

Copper affects steroidogenesis and viability of human adrenocortical carcinoma (NCI-H295R) cell line in vitro

Copper is an environmental risk factor, which has various effects on reproductive endocrinology. In this study human adrenocortical carcinoma (NCI-H295R) cell line was used as an in vitro biological model to study the effect of copper sulfate (CuSO₄.5H₂O) on steroidogenesis and cytotoxicity. The cell cultures were exposed to different concentrations (3.90, 62.50, 250, 500, 1000 µM) of CuSO₄.5H₂O and compared to control group (medium without CuSO₄.5H₂O). Cell viability was measured by the metabolic activity assay. Quantification of sexual steroid production directly from the medium was performed by ELISA assay. Following 48 h culture of NCI-H295R cell line in the presence of CuSO₄.5H₂O a dose-dependent depletion of progesterone release was observed even at the lower concentrations of CuSO₄.5H₂O. The lowest levels of progesterone were detected in groups with the higher doses (≥ 250 µM) of CuSO₄.5H₂O, which elicited significant cytotoxic action. Testosterone production decreased significantly, and this decline was more prominent in comparison to that of progesterone. The lowest release of testosterone was recorded at 1000 µM of CuSO₄.5H₂O. The cytotoxic effect of CuSO₄.5H₂O was evident at all concentrations used in the study. The presented data suggest that copper has detrimental effects on sexual steroid hormones and consecutively on reproductive physiology.

Cytotoxic Effect of Trabectedin In Human Adrenocortical Carcinoma Cell Lines and Primary Cells

Mitotane is the only drug approved for the treatment of adrenocortical carcinoma (ACC). The regimen to be added to mitotane is a chemotherapy including etoposide, doxorubicin, and cisplatin. This pharmacological approach, however, has a limited efficacy and significant toxicity. Evidence indicates that ACC seems to be sensitive to alkylating agents. Trabectedin is an anti-tumor drug that acts as an alkylating agent with a complex mechanism of action. Here, we investigated whether trabectedin could exert a cytotoxic activity in in vitro cell models of ACC. Cell viability was evaluated by MTT assay on ACC cell lines and primary cell cultures. The gene expression was evaluated by q-RT-PCR, while protein expression and localization were studied by Western blot and immunocytochemistry. Combination experiments were performed to evaluate their interaction on ACC cell line viability. Trabectedin demonstrated high cytotoxicity at sub-nanomolar concentrations in ACC cell lines and patient-derived primary cell cultures. The drug was able to reduce /β catenin nuclear localization, although it is unclear whether this effect is involved in the observed cytotoxicity. Trabectedin/mitotane combination exerted a synergic cytotoxic effect in NCI-H295R cells. Trabectedin has antineoplastic activity in ACC cells. The synergistic cytotoxic activity of trabectedin with mitotane provides the rationale for testing this combination in a clinical study.

Ginsenoside Rd attenuates ACTH-induced corticosterone secretion by blocking the MC2R-cAMP/PKA/CREB pathway in Y1 mouse adrenocortical cells

BACKGROUND

Higher levels of glucocorticoids (GCs), and impaired regulation of the hypothalamic-pituitary-adrenal (HPA) axis may cause or exacerbate the occurrence of metabolic and psychiatric disorders. It has been reported that ginseng saponin extract (GSE) has an inhibitory effect on the hyperactivity of the HPA axis induced by stresses and increased corticosterone level induced by intraperitoneal injection of adrenocorticotrophic hormone (ACTH) in mice. However, the molecular mechanisms by which GSE and its active ginsenosides inhibit corticosterone secretion remain elusive.

MAIN METHODS

Y1 mouse adrenocortical cells were treated with ACTH for up to 60 min to establish a cell model of corticosterone secretion. After treatment with different concentrations of GSE or ginsenoside monomers for 24 h prior to the addition of ACTH, analyses of cAMP content, PKA activity, and the levels of steroidogenesis regulators, melanocortin-2 receptor (MC2R), and melanocortin-2 receptor accessory protein (MRAP) in ACTH-induced Y1 cells were performed.

RESULTS

We demonstrated that GSE inhibits ACTH-stimulated corticosterone production in Y1 cells by inhibiting factors critical for steroid synthesis. Ginsenoside Rd, an active ingredient of GSE, inhibits corticosterone secretion in the cells and impedes ACTH-induced corticosterone biosynthesis through down-regulation of proteins in the cAMP/PKA/CREB signaling pathway. In addition, Western blot and qPCR analyses showed that ginsenoside Rd attenuated the induction of MC2R and MRAP by ACTH.

CONCLUSION

Our findings indicate that ginsenoside Rd inhibits ACTH-induced corticosterone production through blockading the MC2R-cAMP/PKA/CREB pathway in adrenocortical cells. Overall, this mechanism may represent an important therapeutic option for the treatment of stress-related disorders, further supporting the pharmacological benefits of ginseng.

GRK2-Mediated Crosstalk Between β-Adrenergic and Angiotensin II Receptors Enhances Adrenocortical Aldosterone Production In Vitro and In Vivo

Aldosterone is produced by adrenocortical zona glomerulosa (AZG) cells in response to angiotensin II (AngII) acting through its type I receptors (AT1Rs). AT1R is a G protein-coupled receptor (GPCR) that induces aldosterone via both G proteins and the adapter protein βarrestin1, which binds the receptor following its phosphorylation by GPCR-kinases (GRKs) to initiate G protein-independent signaling. β-adrenergic receptors (ARs) also induce aldosterone production in AZG cells. Herein, we investigated whether GRK2 or GRK5, the two major adrenal GRKs, is involved in the catecholaminergic regulation of AngII-dependent aldosterone production. In human AZG (H295R) cells in vitro, the βAR agonist isoproterenol significantly augmented both AngII-dependent aldosterone secretion and synthesis, as measured by the steroidogenic acute regulatory (StAR) protein and CYP11B2 (aldosterone synthase) mRNA inductions. Importantly, GRK2, but not GRK5, was indispensable for the βAR-mediated enhancement of aldosterone in response to AngII. Specifically, GRK2 inhibition with Cmpd101 abolished isoproterenol's effects on AngII-induced aldosterone synthesis/secretion, whereas the GRK5 knockout via CRISPR/Cas9 had no effect. It is worth noting that these findings were confirmed in vivo, since rats overexpressing GRK2, but not GRK5, in their adrenals had elevated circulating aldosterone levels compared to the control animals. However, treatment with the β-blocker propranolol prevented hyperaldosteronism in the adrenal GRK2-overexpressing rats. In conclusion, GRK2 mediates a βAR-AT1R signaling crosstalk in the adrenal cortex leading to elevated aldosterone production. This suggests that adrenal GRK2 may be a molecular link connecting the sympathetic nervous and renin-angiotensin systems at the level of the adrenal cortex and that its inhibition might be therapeutically advantageous in hyperaldosteronism-related conditions.

Effects of Adipocyte-derived Factors on the Adrenal Cortex

Background and Objective:

Obesity is highly complicated by hypertension and hyperglycemia. In particular, it has been proposed that obesity-related hypertension is caused by adipocyte-derived factors that are recognized as undetermined proteins secreted from adipocytes. Adipocyte-derived factors have been known to be related to aldosterone secretion in the adrenal gland. So far, Wnt proteins, CTRP-1, VLDL, LDL, HDL and leptin have been demonstrated to stimulate aldosterone secretion. In contrast, it has not yet been clarified whether adipocyte-derived factors also affect adrenal cortisol secretion.

Methods and Results:

In the present study, we investigated the effect of adipocyte-derived factors on cortisol synthase gene CYP11B1 mRNA expression in vitro study using adrenocortical carcinoma H295R cells and mouse fibroblast 3T3-L1cells. Interestingly, adipocyte-derived factors were demonstrated to have the ability to stimulate CYP11B1 mRNA expression.

Conclusion:

Since CYP11B1 is well known as a limiting enzyme of cortisol synthesis, our study suggests that adipocyte-derived factors may stimulate cortisol secretion, as well as aldosterone secretion. Taken together, adipocyte-derived factors may be the cause of metabolic syndrome due to their stimulating effects on aldosterone/cortisol secretion. Therefore, the innovation of novel drugs against them may possibly be a new approach against metabolic syndrome.

Involvement of CREB-regulated transcription coactivators (CRTC) in transcriptional activation of steroidogenic acute regulatory protein (Star) by ACTH

Studies in vivo have suggested the involvement of CREB-regulated transcription coactivator (CRTC)2 on ACTH-induced transcription of the key steroidogenic protein, Steroidogenic Acute Regulatory (StAR). The present study uses two ACTH-responsive adrenocortical cell lines, to examine the role of CRTC on Star transcription. Here we show that ACTH-induced Star primary transcript, or heteronuclear RNA (hnRNA), parallels rapid increases in nuclear levels of the 3 isoforms of CRTC; CRTC1, CRTC2 and CRTC3. Furthermore, ACTH promotes recruitment of CRTC2 and CRTC3 by the Star promoter and siRNA knockdown of either CRTC3 or CRTC2 attenuates the increases in ACTH-induced Star hnRNA. Using pharmacological inhibitors of PKA, MAP kinase and calcineurin, we show that the effects of ACTH on Star transcription and CRTC nuclear translocation depend predominantly on the PKA pathway. The data provides evidence that CRTC2 and CRTC3, contribute to activation of Star transcription by ACTH, and that PKA/CRTC-dependent pathways are part of the multifactorial mechanisms regulating Star transcription.

In vitro cytotoxicity of cabazitaxel in adrenocortical carcinoma cell lines and human adrenocortical carcinoma primary cell cultures☆

Adrenocortical cancer (ACC) is a rare and aggressive malignancy with a poor prognosis. The overall 5-year survival rate of patients with ENS@T stage IV ACC is less than 15%. Systemic antineoplastic therapies have a limited efficacy and new drugs are urgently needed. Human ACC primary cultures and cell lines were used to assess the cytotoxic effect of cabazitaxel, and the role of P-glycoprotein in mediating this effect. Cabazitaxel reduced ACC cell viability, both in ACC cell lines and in ACC primary cell cultures. Molecular and pharmacological targeting of ABCB1/P-gp did not modify its cytotoxic effect in NCI-H295R cells, while it increased the paclitaxel-induced toxicity. Cabazitaxel modified the expression of proteins involved in cellular physiology, such as apoptosis and cell cycle regulation. The drug combination cabazitaxel/mitotane exerted an additive/moderate synergism in different ACC cell experimental models. These results provide a rationale for testing cabazitaxel in a clinical study.

Splice-variant-specific effects of primary aldosteronism point mutations on human CaV3.2 calcium channels

Ca_V3.2 calcium channels play important roles in both neural excitability and aldosterone secretion. Recent clinical studies found four germline mutations (S196 L, M1549I, V1951E and P2083 L) in Ca_V3.2 channels. All four mutations caused primary aldosteronism (PA), while only the M1549I mutation resulted in obvious neural malfunctions besides PA. In human, there are two major Ca_V3.2 channel gene (CACNA1H) splice variants, either with or without exon 26. In this study, we tested the expression of the two CACNA1H splice variants in zona glomerulosa (ZG) cells of human adrenal cortex and the possibility that Ca_V3.2 (-26) and Ca_V3.2 (+26) channels have different functional responses to the four PA mutations. We found that human ZG cells only express long form Ca_V3.2(+26) channels. The M1549I mutation slowed the inactivation of Ca_V3.2(+26) more than 5 fold, and Ca_V3.2(-26) more than 2 fold. The S196 L, V1951E and P2083 L mutations accelerated channel recovery from inactivation for Ca_V3.2(+26), but not Ca_V3.2(-26) channels. All four mutations resulted in gain of function of Ca_V3.2(+26) channels, leading to overproduction of aldosterone. In conclusion, the four PA mutations caused more profound changes on Ca_V3.2 (+26) currents than on Ca_V3.2 (-26) currents, and except the M1549I mutation, the S196 L, V1951E and P2083 L have little effect on the electrophysiological properties of Ca_V3.2(-26) currents, which may partially explain the limitation of the phenotype associated with the V1951E, S196 L and P2083 L germline mutations to PA.

Adrenal βarrestin1 targeting for tobacco-associated cardiac dysfunction treatment: Aldosterone production as the mechanistic link

Tobacco kills 6 million people annually and its global health costs are continuously rising. The main addictive component of every tobacco product is nicotine. Among the mechanisms by which nicotine, and its major metabolite, cotinine, contribute to heart disease is the renin-angiotensin-aldosterone system (RAAS) activation. This increases aldosterone production from the adrenals and circulating aldosterone levels. Aldosterone is a mineralocorticoid hormone with various direct harmful effects on the myocardium, including increased reactive oxygen species (ROS) generation, which contributes significantly to cardiac mitochondrial dysfunction and cardiac aging. Aldosterone is produced in the adrenocortical zona glomerulosa (AZG) cells in response to angiotensin II (AngII), activating its type 1 receptor (AT1R). The AT1R is a G protein-coupled receptor (GPCR) that leads to aldosterone biosynthesis and secretion, via signaling from both Gq/11 proteins and the GPCR adapter protein βarrestin1, in AZG cells. Adrenal βarrestin1 is essential for AngII-dependent adrenal aldosterone production, which aggravates heart disease. Since adrenal βarrestin1 is essential for raising circulating aldosterone in the body and tobacco compounds are also known to elevate aldosterone levels in smokers, accelerating heart disease progression, our central hypothesis is that nicotine and cotinine increase aldosterone levels to induce cardiac injury by stimulating adrenal βarrestin1. In the present review, we provide an overview of the current literature of the physiology and pharmacology of adrenal aldosterone production regulation, of the effects of tobacco on this process and, finally, of the effects of tobacco and aldosterone on cardiac structure and function, with a particular focus on cardiac mitochondrial function. We conclude our literature account with a brief experimental outline, as well as with some therapeutic perspectives of our pharmacological hypothesis, that is that adrenal βarrestin1 is a novel molecular target for preventing tobacco-induced hyperaldosteronism, thereby also ameliorating tobacco-related heart disease development.

5-oxo-ETE activates migration of H295R adrenocortical cells via MAPK and PKC pathways

The OXE receptor is a GPCR activated by eicosanoids produced by the action of 5-lipoxygenase. We previously found that this membrane receptor participates in the regulation of cAMP-dependent and -independent steroidogenesis in human H295R adrenocortical carcinoma cells. In this study we analyzed the effects of the OXE receptor physiological activator 5-oxo-ETE on the growth and migration of H259R cells. While 5-oxo-ETE did not affect the growth of H295R cells, overexpression of OXE receptor caused an increase in cell proliferation, which was further increased by 5-oxo-ETE and blocked by 5-lipoxygenase inhibition. 5-oxo-ETE increased the migratory capacity of H295R cells in wound healing assays, but it did not induce the production of metalloproteases MMP-1, MMP-2, MMP-9 and MMP-10. The pro-migratory effect of 5-oxo-ETE was reduced by pharmacological inhibition of the MEK/ERK1/2, p38 and PKC pathways. 5-oxo-ETE caused significant activation of ERK and p38. ERK activation by the eicosanoid was reduced by the "pan" PKC inhibitor GF109203X but not by the classical PKC inhibitor Gö6976, suggesting the involvement of novel PKCs in this effect. Although H295R cells display detectable phosphorylation of Ser299 in PKCδ, a readout for the activation of this novel PKC, treatment with 5-oxo-ETE per se was unable to induce additional PKCδ activation. Our results revealed signaling effectors activated by 5-oxo-ETE in H295R cells and may have significant implications for our understanding of OXE receptor in adrenocortical cell pathophysiology.

Adrenocortical cancer cell line mutational profile reveals aggressive genetic background

Adrenocortical carcinomas are rare tumors with poor prognosis and limited treatment options. Although widely used as in vitro models to test novel therapeutic strategies, the adrenocortical carcinoma-derived cell lines NCI-H295R and SW-13 have only partially been described genetically. Our aim was to characterize the mutational landscape of these cells to improve their experimental utility and map them to clinical subtypes of adrenocortical carcinoma. Genomic DNA from NCI-H295R and SW-13 cells was subjected to whole-exome sequencing. Variants were filtered for non-synonymous mutations and curated for validated adrenocortical and pan-cancer driver gene mutations. Genes mutated in the cell lines were mapped using gene ontology and protein pathway tools to determine signaling effects and compared to mutational and clinical characteristics of 92 adrenocortical carcinoma cases from The Cancer Genome Atlas. NCI-H295R and SW-13 cells carried 1325 and 1836 non-synonymous variants, respectively. Of these, 61 and 76 were known cancer driver genes, of which 32 were shared between cell lines. Variant interaction analyses demonstrated dominant TP53 dysregulation in both cell lines complemented by distinct WNT (NCI-H295R) and chromatin remodeling (SW-13) pathway perturbations. Both cell lines genetically resemble more aggressive adrenocortical carcinomas with worse prognosis, for which development of targeted therapies is most critical. Careful incorporation of the genetic landscapes outlined in this study will further the in vitro utility of these cell lines in testing for novel therapeutic approaches for adrenocortical malignancy.

In vitro antitumor activity of progesterone in human adrenocortical carcinoma

PURPOSE

The management of patients with adrenocortical carcinoma (ACC) is challenging. As mitotane and chemotherapy show limited efficacy, there is an urgent need to develop therapeutic approaches. The aim of this study was to investigate the antitumor activity of progesterone and explore the molecular mechanisms underlying its cytotoxic effects in the NCI-H295R cell line and primary cell cultures derived from ACC patients.

METHODS

Cell viability, cell cycle, and apoptosis were analyzed in untreated and progesterone-treated ACC cells. The ability of progesterone to affect the Wnt/β-catenin pathway in NCI-H295R cells was investigated by immunofluorescence. Progesterone and mitotane combination experiments were also performed to evaluate their interaction on NCI-H295R cell viability.

RESULTS

We demonstrated that progesterone exerted a concentration-dependent inhibition of ACC cell viability. Apoptosis was the main mechanism, as demonstrated by a significant increase of apoptosis and cleaved-Caspase-3 levels. Reduction of β-catenin nuclear translocation may contribute to the progesterone cytotoxic effect. The progesterone antineoplastic activity was synergically increased when mitotane was added to the cell culture medium.

CONCLUSIONS

Our results show that progesterone has antineoplastic activity in ACC cells. The synergistic cytotoxic activity of progesterone with mitotane provides the rationale for testing this combination in a clinical study.

Endogenous H2S resists mitochondria-mediated apoptosis in the adrenal glands via ATP5A1 S-sulfhydration in male mice

In a previous study, we showed that endogenous hydrogen sulfide (H₂S) plays a key role in the maintenance of intact adrenal cortex function via the protection of mitochondrial function during endoxemia. We further investigated whether mitochondria-mediated apoptosis is involved in H₂S protection of adrenal function. LPS treatment resulted in mitochondria-mediated apoptosis in the adrenal glands of male mice, and these effects were prevented by the H₂S donor GYY4137. In the model of Y1 cells, the LPS-induced mitochondria-mediated apoptosis and blunt response to ACTH were rescued by GYY4137. The H₂S-generating enzyme cystathionine-β-synthase (CBS) knockout heterozygous (CBS^+/-) mice showed mitochondria-mediated apoptosis in the adrenal gland and adrenal insufficiency. GYY4137 treatment restored adrenal function and eliminated mitochondria-mediated apoptosis. Maleimide assay combined with mass spectrometry analysis showed that a number of proteins in mitochondria were S-sulfhydrated in the adrenal gland. ATP5A1 was further confirmed as S-sulfhydrated using a modified biotin switch assay. The level of S-sulfhydrated ATP5A1 was decreased in the adrenal gland of endotoxemic and CBS^+/- mice, which was restored by GYY4137. ATP5A1 was identified as sulfhydrated at cysteine 244 by H₂S. Overexpression of the cysteine 244 mutant ATP5A1 in Y1 cells resulted in a loss of LPS-induced mitochondria-mediated apoptosis and GYY4137 restoration of LPS-induced hyporesponsiveness to ACTH. Collectively, the present study revealed that decreased H₂S generation leads to mitochondrial-mediated apoptosis in the adrenal cortex and a blunt response to ACTH. S-sulfhydration of ATP5A1 at cysteine 244 is an important molecular mechanism by which H₂S maintains mitochondrial function and steroidogenesis in the adrenal glands.