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Cook JR, Ausiello J. Functional ACE2 deficiency leading to angiotensin imbalance in the pathophysiology of COVID-19. Rev Endocr Metab Disord 2022; 23:151-170. [PMID: 34195965 PMCID: PMC8245275 DOI: 10.1007/s11154-021-09663-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/04/2021] [Indexed: 02/07/2023]
Abstract
SARS-CoV-2, the virus responsible for COVID-19, uses angiotensin converting enzyme 2 (ACE2) as its primary cell-surface receptor. ACE2 is a key enzyme in the counter-regulatory pathway of the broader renin-angiotensin system (RAS) that has been implicated in a broad array of human pathology. The RAS is composed of two competing pathways that work in opposition to each other: the "conventional" arm involving angiotensin converting enzyme (ACE) generating angiotensin-2 and the more recently identified ACE2 pathway that generates angiotensin (1-7). Following the original SARS pandemic, additional studies suggested that coronaviral binding to ACE2 resulted in downregulation of the membrane-bound enzyme. Given the similarities between the two viruses, many have posited a similar process with SARS-CoV-2. Proponents of this ACE2 deficiency model argue that downregulation of ACE2 limits its enzymatic function, thereby skewing the delicate balance between the two competing arms of the RAS. In this review we critically examine this model. The available data remain incomplete but are consistent with the possibility that the broad multisystem dysfunction of COVID-19 is due in large part to functional ACE2 deficiency leading to angiotensin imbalance with consequent immune dysregulation and endothelial cell dysfunction.
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Affiliation(s)
- Joshua R Cook
- New York-Presbyterian Hospital and the Columbia University Irving Medical Center, New York, NY, USA
| | - John Ausiello
- New York-Presbyterian Hospital and the Columbia University Irving Medical Center, New York, NY, USA.
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2
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Habibi J, Chen D, Hulse JL, Whaley-Connell A, Sowers JR, Jia G. Targeting mineralocorticoid receptors in diet-induced hepatic steatosis and insulin resistance. Am J Physiol Regul Integr Comp Physiol 2022; 322:R253-R262. [PMID: 35107025 PMCID: PMC8896998 DOI: 10.1152/ajpregu.00316.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mineralocorticoid receptor (MR) activation plays an important role in hepatic insulin resistance. However, the precise mechanisms by which MR activation promotes hepatic insulin resistance remains unclear. Therefore, we sought to investigate the roles and mechanisms by which MR activation promotes Western diet (WD)-induced hepatic steatosis and insulin resistance. Six-week-old C57BL6J mice were fed either mouse chow or a WD, high in saturated fat and refined carbohydrates, with or without the MR antagonist spironolactone (1 mg/kg/day) for 16 wk. WD feeding resulted in systemic insulin resistance at 8 and 16 wk. WD also induced impaired hepatic insulin metabolic signaling via phosphoinositide 3-kinases/protein kinase B pathways, which was associated with increased hepatic CD36, fatty acid transport proteins, fatty acid-binding protein-1, and hepatic steatosis. Meanwhile, consumption of a WD-induced hepatic mitochondria dysfunction, oxidative stress, and inflammatory responses. These abnormalities occurring in response to WD feeding were blunted with spironolactone treatment. Moreover, spironolactone promoted white adipose tissue browning and hepatic glucose transporter type 4 expression. These data suggest that enhanced hepatic MR signaling mediates diet-induced hepatic steatosis and dysregulation of adipose tissue browning, and subsequent hepatic mitochondria dysfunction, oxidative stress, inflammation, as well as hepatic insulin resistance.
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Affiliation(s)
- Javad Habibi
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri
| | - Dongqing Chen
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri
| | - Jack L. Hulse
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri
| | - Adam Whaley-Connell
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,2Division of Nephrology and Hypertension, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri
| | - James R. Sowers
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,2Division of Nephrology and Hypertension, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri,4Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri,5Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri
| | - Guanghong Jia
- 1Division of Endocrinology and Metabolism, Department of Medicine, University of Missouri School of Medicine, Columbia, Missouri,3Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, Missouri,4Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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3
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Tsilosani A, Gao C, Zhang W. Aldosterone-Regulated Sodium Transport and Blood Pressure. Front Physiol 2022; 13:770375. [PMID: 35197862 PMCID: PMC8859437 DOI: 10.3389/fphys.2022.770375] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 01/06/2022] [Indexed: 11/13/2022] Open
Abstract
Aldosterone is a major mineralocorticoid steroid hormone secreted by glomerulosa cells in the adrenal cortex. It regulates a variety of physiological responses including those to oxidative stress, inflammation, fluid disruption, and abnormal blood pressure through its actions on various tissues including the kidney, heart, and the central nervous system. Aldosterone synthesis is primarily regulated by angiotensin II, K+ concentration, and adrenocorticotrophic hormone. Elevated serum aldosterone levels increase blood pressure largely by increasing Na+ re-absorption in the kidney through regulating transcription and activity of the epithelial sodium channel (ENaC). This review focuses on the signaling pathways involved in aldosterone synthesis and its effects on Na+ reabsorption through ENaC.
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Affiliation(s)
- Akaki Tsilosani
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
| | - Chao Gao
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
| | - Wenzheng Zhang
- Department of Regenerative & Cancer Cell Biology, Albany Medical College, Albany, NY, United States
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4
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Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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5
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Rajora MA, Zheng G. Targeting SR-BI for Cancer Diagnostics, Imaging and Therapy. Front Pharmacol 2016; 7:326. [PMID: 27729859 PMCID: PMC5037127 DOI: 10.3389/fphar.2016.00326] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/06/2016] [Indexed: 01/13/2023] Open
Abstract
Scavenger receptor class B type I (SR-BI) plays an important role in trafficking cholesteryl esters between the core of high density lipoprotein and the liver. Interestingly, this integral membrane protein receptor is also implicated in the metabolism of cholesterol by cancer cells, whereby overexpression of SR-BI has been observed in a number of tumors and cancer cell lines, including breast and prostate cancers. Consequently, SR-BI has recently gained attention as a cancer biomarker and exciting target for the direct cytosolic delivery of therapeutic agents. This brief review highlights these key developments in SR-BI-targeted cancer therapies and imaging probes. Special attention is given to the exploration of high density lipoprotein nanomimetic platforms that take advantage of upregulated SR-BI expression to facilitate targeted drug-delivery and cancer diagnostics, and promising future directions in the development of these agents.
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Affiliation(s)
- Maneesha A Rajora
- Princess Margaret Cancer Centre and Techna Institute, University Health NetworkToronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto, ON, Canada
| | - Gang Zheng
- Princess Margaret Cancer Centre and Techna Institute, University Health NetworkToronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of TorontoToronto, ON, Canada; Department of Medical Biophysics, University of TorontoToronto, ON, Canada
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Huang H, Cruz W, Chen J, Zheng G. Learning from biology: synthetic lipoproteins for drug delivery. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2015; 7:298-314. [PMID: 25346461 PMCID: PMC4397116 DOI: 10.1002/wnan.1308] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/22/2014] [Accepted: 09/02/2014] [Indexed: 12/15/2022]
Abstract
Synthetic lipoproteins represent a relevant tool for targeted delivery of biological/chemical agents (chemotherapeutics, siRNAs, photosensitizers, and imaging contrast agents) into various cell types. These nanoparticles offer a number of advantages for drugs delivery over their native counterparts while retaining their natural characteristics and biological functions. Their ultra-small size (<30 nm), high biocompatibility, favorable circulation half-life, and natural ability to bind specific lipoprotein receptors, i.e., low-density lipoprotein receptor (LDLR) and Scavenger receptor class B member 1 (SRB1) that are found in a number of pathological conditions (e.g., cancer, atherosclerosis), make them superior delivery strategies when compared with other nanoparticle systems. We review the various approaches that have been developed for the generation of synthetic lipoproteins and their respective applications in vitro and in vivo. More specifically, we summarize the approaches employed to address the limitation on use of reconstituted lipoproteins by means of natural or recombinant apolipoproteins, as well as apolipoprotein mimetic molecules. Finally, we provide an overview of the advantages and disadvantages of these approaches and discuss future perspectives for clinical translation of these nanoparticles.
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Affiliation(s)
- Huang Huang
- DLVR Therapeutics Inc., Toronto, Canada
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada M5G 1L7
| | - William Cruz
- DLVR Therapeutics Inc., Toronto, Canada
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada M5G 1L7
| | - Juan Chen
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada M5G 1L7
| | - Gang Zheng
- Princess Margaret Cancer Center, University Health Network, Toronto, ON, Canada M5G 1L7
- Department of Medical Biophysics, University of Toronto, Toronto, ON Canada M5G 1L7
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Al-Jarallah A, Chen X, González L, Trigatti BL. High density lipoprotein stimulated migration of macrophages depends on the scavenger receptor class B, type I, PDZK1 and Akt1 and is blocked by sphingosine 1 phosphate receptor antagonists. PLoS One 2014; 9:e106487. [PMID: 25188469 PMCID: PMC4154704 DOI: 10.1371/journal.pone.0106487] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 08/04/2014] [Indexed: 01/12/2023] Open
Abstract
HDL carries biologically active lipids such as sphingosine-1-phosphate (S1P) and stimulates a variety of cell signaling pathways in diverse cell types, which may contribute to its ability to protect against atherosclerosis. HDL and sphingosine-1-phosphate receptor agonists, FTY720 and SEW2871 triggered macrophage migration. HDL-, but not FTY720-stimulated migration was inhibited by an antibody against the HDL receptor, SR-BI, and an inhibitor of SR-BI mediated lipid transfer. HDL and FTY720-stimulated migration was also inhibited in macrophages lacking either SR-BI or PDZK1, an adaptor protein that binds to SR-BI's C-terminal cytoplasmic tail. Migration in response to HDL and S1P receptor agonists was inhibited by treatment of macrophages with sphingosine-1-phosphate receptor type 1 (S1PR1) antagonists and by pertussis toxin. S1PR1 activates signaling pathways including PI3K-Akt, PKC, p38 MAPK, ERK1/2 and Rho kinases. Using selective inhibitors or macrophages from gene targeted mice, we demonstrated the involvement of each of these pathways in HDL-dependent macrophage migration. These data suggest that HDL stimulates the migration of macrophages in a manner that requires the activities of the HDL receptor SR-BI as well as S1PR1 activity.
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Affiliation(s)
- Aishah Al-Jarallah
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Xing Chen
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Leticia González
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Bernardo L. Trigatti
- Department of Biochemistry and Biomedical Sciences, and the Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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Nishimoto K, Harris RBS, Rainey WE, Seki T. Sodium deficiency regulates rat adrenal zona glomerulosa gene expression. Endocrinology 2014; 155:1363-72. [PMID: 24422541 PMCID: PMC3959598 DOI: 10.1210/en.2013-1999] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Aldosterone is the primary adrenocortical hormone regulating sodium retention, and its production is under the control of the renin-angiotensin-aldosterone system (RAAS). In vitro, angiotensin II can induce aldosterone production in adrenocortical cells without causing cell proliferation. In vivo, a low-sodium diet activates the RAAS and aldosterone production, at least in part, through an expansion of the adrenal zona glomerulosa (zG) layer. Although these mechanisms have been investigated, RAAS effects on zG gene expression have not been fully elucidated. In this study, we took an unbiased approach to define the complete list of zG transcripts involved in RAAS activation. Adrenal glands were collected from 11-week old Sprague-Dawley rats fed either sodium-deficient (SDef), normal sodium (NS), or high-sodium (HS) diet for 72 hours, and laser-captured zG RNA was analyzed on microarrays containing 27 342 probe sets. When the SDef transcriptome was compared with NS transcriptome (SDef/NS comparison), only 79 and 10 probe sets were found to be up- and down-regulated more than two-fold in SDef, respectively. In SDef/HS comparison, 201 and 68 probe sets were up- and down-regulated in SDef, respectively. Upon gene ontology (GO) analysis of these gene sets, we identified three groups of functionally related GO terms: cell proliferation-associated (group 1), response to stimulus-associated (group 2), and cholesterol/steroid metabolism-associated (group 3) GO terms. Although genes in group 1 may play a critical role in zG layer expansion, those in groups 2 and 3 may have important functions in aldosterone production, and further investigations on these genes are warranted.
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Affiliation(s)
- Koshiro Nishimoto
- Department of Molecular and Integrative Physiology (K.N., W.E.R.), University of Michigan, Ann Arbor, Michigan 48109; Department of Physiology (R.B.S.H., T.S.), Georgia Regents University, Augusta, Georgia 30912; and Department of Urology (K.N.), Tachikawa Hospital, Tachikawa, 190-0022 Tokyo, Japan
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Ma KL, Ni J, Wang CX, Liu J, Zhang Y, Wu Y, Lv LL, Ruan XZ, Liu BC. Interaction of RAS activation and lipid disorders accelerates the progression of glomerulosclerosis. Int J Med Sci 2013; 10:1615-24. [PMID: 24151433 PMCID: PMC3804787 DOI: 10.7150/ijms.6635] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 08/30/2013] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The activation of the renin-angiotensin system (RAS) and lipid disorders are major risk factors in progressive chronic kidney disease. This study aimed to investigate the potential synergistic mechanisms of RAS activation and lipid disorders that contribute to glomerulosclerosis. MATERIALS AND METHODS Human renal mesangial cells (HMCs) were treated with 10(-7) mol/L angiotensin II (Ang II) or with 30 μg/ml cholesterol and 1 μg/ml 25-hydroxycholesterol (lipid loading) for 24 hours. Lipid accumulation in the cells was evaluated by Oil Red O staining and intracellular cholesterol quantitative assays. The gene and protein expression of molecules in the low-density lipoprotein receptor (LDLr) pathway, the RAS family, and the extracellular matrix were examined by real-time polymerase chain reaction and Western blotting. The translocation of sterol regulatory element-binding protein (SREBP) cleavage activating protein (SCAP), which escorts SREBP-2 from the endoplasmic reticulum (ER) to the Golgi, was examined by immunofluorescent staining. RESULTS Ang II increased lipid droplet accumulation in HMCs. Further analysis revealed that Ang II increased the mRNA and protein expression of LDLr, SCAP, and SREBP-2. This increase was correlated with an enhanced translocation of the SCAP/SREBP-2 complex from the ER to the Golgi in HMCs that was induced by Ang II, thereby activating LDLr gene transcription. Interestingly, lipid loading increased the mRNA and protein expression of angiotensinogen, Ang II, renin, angiotensin-converting enzyme, angiotensin II type 1 receptor, and type 2 receptor in HMCs with increased mRNA and protein expression of collagen I, α-smooth muscle actin, and fibronectin. CONCLUSIONS This study demonstrates that the interaction of RAS activation and lipid disorders accelerates the progression of glomerulosclerosis.
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Affiliation(s)
- Kun-Ling Ma
- 1. Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing City, Jiangsu Province, P.R. China
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Hattangady N, Olala L, Bollag WB, Rainey WE. Acute and chronic regulation of aldosterone production. Mol Cell Endocrinol 2012; 350:151-62. [PMID: 21839803 PMCID: PMC3253327 DOI: 10.1016/j.mce.2011.07.034] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/11/2011] [Accepted: 07/17/2011] [Indexed: 11/28/2022]
Abstract
Aldosterone is the major mineralocorticoid synthesized by the adrenal and plays an important role in the regulation of systemic blood pressure through the absorption of sodium and water. Aldosterone production is regulated tightly by selective expression of aldosterone synthase (CYP11B2) in the adrenal outermost zone, the zona glomerulosa. Angiotensin II (Ang II), potassium (K(+)) and adrenocorticotropin (ACTH) are the main physiological agonists which regulate aldosterone secretion. Aldosterone production is regulated within minutes of stimulation (acutely) through increased expression and phosphorylation of the steroidogenic acute regulatory (StAR) protein and over hours to days (chronically) by increased expression of the enzymes involved in the synthesis of aldosterone, particularly CYP11B2. Imbalance in any of these processes may lead to several disorders of aldosterone excess. In this review we attempt to summarize the key molecular events involved in the acute and chronic phases of aldosterone secretion.
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Affiliation(s)
- Namita Hattangady
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
| | - Lawrence Olala
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
| | - Wendy B. Bollag
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
- Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA 30904
| | - William E. Rainey
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
- To whom correspondence should be addressed: William E. Rainey, Department of Physiology, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912, , Tel: (706) 721-7665, Fax: (706) 721-7299
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Modified high-density lipoprotein modulates aldosterone release through scavenger receptors via extra cellular signal-regulated kinase and Janus kinase-dependent pathways. Mol Cell Biochem 2012; 366:1-10. [DOI: 10.1007/s11010-012-1274-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 02/16/2012] [Indexed: 02/02/2023]
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12
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Lucki NC, Li D, Sewer MB. Sphingosine-1-phosphate rapidly increases cortisol biosynthesis and the expression of genes involved in cholesterol uptake and transport in H295R adrenocortical cells. Mol Cell Endocrinol 2012; 348:165-75. [PMID: 21864647 PMCID: PMC3508734 DOI: 10.1016/j.mce.2011.08.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 07/26/2011] [Accepted: 08/03/2011] [Indexed: 12/22/2022]
Abstract
In the acute phase of adrenocortical steroidogenesis, adrenocorticotrophin (ACTH) activates a cAMP/PKA-signaling pathway that promotes the transport of free cholesterol to the inner mitochondrial membrane. We have previously shown that ACTH rapidly stimulates the metabolism of sphingolipids and the secretion of sphingosine-1-phosphate (S1P) in H295R cells. In this study, we examined the effect of S1P on genes involved in the acute phase of steroidogenesis. We show that S1P increases the expression of steroidogenic acute regulatory protein (StAR), 18-kDa translocator protein (TSPO), low-density lipoprotein receptor (LDLR), and scavenger receptor class B type I (SR-BI). S1P-induced StAR mRNA expression requires Gα(i) signaling, phospholipase C (PLC), Ca(2+)/calmodulin-dependent kinase II (CamKII), and ERK1/2 activation. S1P also increases intracellular Ca(2+), the phosphorylation of hormone sensitive lipase (HSL) at Ser(563), and cortisol secretion. Collectively, these findings identify multiple roles for S1P in the regulation of glucocorticoid biosynthesis.
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Affiliation(s)
- Natasha C. Lucki
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30332-0230
| | - Donghui Li
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0704
| | - Marion B. Sewer
- Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093-0704
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Mechanistic profiling of the cAMP-dependent steroidogenic pathway in the H295R endocrine disrupter screening system: new endpoints for toxicity testing. Toxicol Lett 2011; 208:174-84. [PMID: 22079614 DOI: 10.1016/j.toxlet.2011.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 01/26/2023]
Abstract
The need for implementation of effects on steroid synthesis and hormone processing in screening batteries of endocrine disruptive compounds is widely acknowledged. In this perspective, hormone profiling in the H295R adrenocortical cell system is extensively examined and recently OECD validated (TG 456) as a replacement of the minced testis assay. To further elucidate the complete mechanisms and endocrine responsiveness of this cell system, microarray-based gene expression profiling of the cAMP response pathway, one of the major pathways in steroidogenesis regulation, was examined in H295R cells. Next to the steroid synthesis pathway, a broader lipid metabolic pathway, including cholesterol uptake/biosynthesis, hormone metabolization and many hormone and nuclear receptors, are sensitive towards cAMP stimulation in this cell system. Moreover, these pathways were clearly dose and time responsive, indicating early regulation (10 h) of cholesterol uptake and mobilization genes and later expression (24-48 h) of cholesterol biosynthesis and steroid synthesis. Transcription network analysis suggested several important transcription factors that could be involved in regulation of the steroid hormone pathway, of which HNF4α, a broader lipid metabolism related transcription factor, might indicate some new transcription regulation patterns in this cell line. Overall we can conclude that the time dependent gene expression patterns of the strongly coordinated cholesterol supply and steroidogenesis pathways in the H295R cell system seem to reflect well the in vivo ACTH/cAMP signalling cascade in adrenal cells. Moreover, the completeness of the steroidogenic related pathways in terms of gene expression sensitivity, indicates the H295R cell line as a promising cell line in omics-based endocrine disruption screening.
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14
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Martinez-Arguelles DB, Guichard T, Culty M, Zirkin BR, Papadopoulos V. In utero exposure to the antiandrogen di-(2-ethylhexyl) phthalate decreases adrenal aldosterone production in the adult rat. Biol Reprod 2011; 85:51-61. [PMID: 21389346 DOI: 10.1095/biolreprod.110.089920] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We previously reported that in utero exposure of the male fetus to the plasticizer di-(2-ethylhexyl) phthalate (DEHP) resulted in decreased circulating levels of testosterone in the adult without affecting Leydig cell numbers, luteinizing hormone levels, or steroidogenic enzyme expression. Fetal exposure to DEHP resulted in reduced mineralocorticoid receptor (MR; NR3C2) expression in adult Leydig cells. In the present studies, treatment of pregnant Sprague-Dawley dams from Gestational Day 14 until birth with 20, 50, 100, 300, or 750 mg kg(-1) day(-1) of DEHP resulted in significant sex-specific decreases in serum aldosterone but not corticosterone levels at Postnatal Day 60 (PND60) but not at PND21. There was no effect on circulating levels of potassium, angiotensin II or adrenocorticotropin hormone (ACTH). However, there was reduced expression of AT receptor Agtr1a, Agtr1b, and Agtr2 mRNAs. The mRNA levels of proteins and enzymes implicated in aldosterone biosynthesis were not affected by in utero DEHP treatment except for Cyp11b2, which was decreased at high (≥ 500 mg kg(-1) day(-1)) doses. The data presented herein, together with our previous observation that aldosterone stimulates testosterone production via an MR-mediated mechanism, suggest that in utero exposure to DEHP causes reduction in both adrenal aldosterone synthesis and MR expression in Leydig cells, leading to reduced testosterone production in the adult. Moreover, these results suggest the existence of a DEHP-sensitive adrenal-testis axis regulating androgen formation.
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Affiliation(s)
- Daniel B Martinez-Arguelles
- Department of Biochemistry & Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC, USA
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15
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Kappelle PJWH, van Tol A, Wolffenbuttel BHR, Dullaart RPF. Cholesteryl Ester Transfer Protein Inhibition in Cardiovascular Risk Management: Ongoing Trials will End the Confusion. Cardiovasc Ther 2010; 29:e89-99. [DOI: 10.1111/j.1755-5922.2010.00201.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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16
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Fuhrman B, Gantman A, Aviram M. Paraoxonase 1 (PON1) deficiency in mice is associated with reduced expression of macrophage SR-BI and consequently the loss of HDL cytoprotection against apoptosis. Atherosclerosis 2010; 211:61-8. [PMID: 20149374 DOI: 10.1016/j.atherosclerosis.2010.01.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2009] [Revised: 01/07/2010] [Accepted: 01/19/2010] [Indexed: 11/25/2022]
Abstract
BACKGROUND Paraoxonase 1 (PON1) was shown to stimulate HDL binding and HDL-mediated cholesterol efflux from macrophages. This study examined the role of PON1 in the expression of proteins that enhance macrophage HDL binding, i.e. ABCA1 and SR-BI. METHODS AND RESULTS ABCA1 expression was similar, whereas SR-BI expression (mRNA and protein determined by FACS, Western blot, or immunocytochemistry) was significantly decreased in peritoneal macrophages from PON1 deficient (MPM-PON1(0)) in comparison to C57Bl/6 (MPM-Control) mice. PON1 deficiency correction with HDL-control, recombinant PON1 (rePON1), or by transfection with a plasmid containing the rePON1 gene, increased SR-BI expression in MPM-PON1(0), whereas rePON1/H115Gln mutant, or the H115Q/H134Q double mutant, which lack catalytic activity, did not stimulate SR-BI expression. Lysophosphatidyl choline (LPC) resulting from PON1 action on macrophage PC, upregulated SR-BI expression in MPM-PON1(0) via activation of ERK1/2 and PI3K. Functionally, HDL bound to MPM-PON1(0) significantly less than to MPM-Control, and failed to inhibit tunicamycin-induced apoptosis, but had no significant effect on HDL-mediated cholesterol efflux from macrophages. CONCLUSIONS PON1 deficiency in mice is associated with decreased macrophage SR-BI expression, decreased cellular HDL binding, and consequently the loss of HDL-mediated cytoprotection against apoptosis, which may contribute to the accelerated atherosclerosis observed in PON1(0) mice. These findings add new insights into the function of SR-BI in macrophages, and define the potential role of PON1 in regulating SR-BI-mediated HDL protection against macrophages apoptosis.
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Affiliation(s)
- Bianca Fuhrman
- The Lipid Research Laboratory, Technion Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, and Rambam Medical Center, 31096 Haifa, Israel.
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17
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Nogueira EF, Bollag WB, Rainey WE. Angiotensin II regulation of adrenocortical gene transcription. Mol Cell Endocrinol 2009; 302:230-6. [PMID: 18812209 PMCID: PMC3752678 DOI: 10.1016/j.mce.2008.08.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 08/21/2008] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) is the key peptide hormone in the renin-angiotensin-aldosterone system (RAAS). Its ability to regulate levels of circulating aldosterone relies on actions on adrenal glomerulosa cells. Many of the Ang II effects on glomerulosa cells involve a precisely coordinated regulation of signaling cascades and gene expression. The development of genome-wide gene arrays has allowed the definition of transcriptome-wide effects of Ang II in adrenocortical cells. Analysis of the Ang II gene targets reveals broad effects on cellular gene expression, particularly the rapid induction of numerous transcription factors that may regulate long-term steroid metabolism and cell growth/proliferation. Herein we discuss the Ang II-induced genes in adrenocortical cells and review the progress in defining the role of these genes in zona glomerulosa function.
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Affiliation(s)
- Edson F. Nogueira
- Department of Physiology, Medical College of Georgia, Augusta, GA – USA
| | - Wendy B. Bollag
- Charlie Norwood VA Medical Center, Augusta, GA – USA
- Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA – USA
| | - William E. Rainey
- Department of Physiology, Medical College of Georgia, Augusta, GA – USA
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18
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Hoekstra M, Ye D, Hildebrand RB, Zhao Y, Lammers B, Stitzinger M, Kuiper J, Van Berkel TJC, Van Eck M. Scavenger receptor class B type I-mediated uptake of serum cholesterol is essential for optimal adrenal glucocorticoid production. J Lipid Res 2009; 50:1039-46. [PMID: 19179307 DOI: 10.1194/jlr.m800410-jlr200] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Impaired scavenger receptor class B type I (SR-BI)-mediated uptake of HDL-cholesterol esters (HDL-CE) induces adrenal insufficiency in mice. Humans contain an alternative route of HDL-CE clearance, namely through the transfer by cholesteryl ester transfer protein (CETP) to apolipoprotein B lipoproteins for subsequent uptake via the LDL receptor. In this study, we determined whether CETP can compensate for loss of adrenal SR-BI. Transgenic expression of human CETP (CETP Tg) in SR-BI knockout (KO) mice increased adrenal HDL-CE clearance from 33-58% of the control value. SR-BI KO/CETP Tg and SR-BI KO mice displayed adrenal hypertrophy due to equally high plasma adrenocorticotropic hormone levels. Adrenal cholesterol levels and plasma corticosterone levels were 38-52% decreased in SR-BI KO mice with and without CETP expression. SR-BI KO/CETP Tg mice also failed to increase their corticosterone level after lipopolysaccharide challenge, leading to an identical >4-fold increased tumor necrosis factor-alpha response compared with controls. These data indicate that uptake of CE via other routes than SR-BI is not sufficient to generate the cholesterol pool needed for optimal adrenal steroidogenesis. In conclusion, we have shown that CETP-mediated transfer of HDL-CE is not able to reverse adrenal insufficiency in SR-BI knockout mice. Thus, SR-BI-mediated uptake of serum cholesterol is essential for optimal adrenal function.
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Affiliation(s)
- Menno Hoekstra
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, 2300RA Leiden, The Netherlands.
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19
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Krikken JA, Dallinga-Thie GM, Navis G, Dullaart RPF. Renin-angiotensin-aldosterone responsiveness to low sodium and blood pressure reactivity to angiotensin-II are unrelated to cholesteryl ester transfer protein mass in healthy subjects. Expert Opin Ther Targets 2009; 12:1321-8. [PMID: 18851690 DOI: 10.1517/14728222.12.11.1321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The blood pressure increase associated with the cholesteryl ester transfer protein (CETP) inhibitor, torcetrapib is probably attributable to an off-target effect but it is unknown whether activation of the renin-angiotensin-aldosterone system (RAAS) may be related to variation in the plasma CETP level. We questioned whether the plasma CETP level would affect RAAS responsiveness to low sodium diet and the blood pressure response to angiotensin-II infusion in healthy subjects. METHODS RAAS parameters and blood pressure were determined during liberal sodium diet (200 mmol/24 h) and low sodium diet (50 mmol/24 h) in 67 healthy men. Blood pressure response to incremental angiotensin-II infusion was assessed in 34 subjects during liberal sodium diet. Correlation analysis was performed to test whether RAAS responsiveness and blood pressure were related to plasma CETP mass, high-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A-I measured during liberal sodium diet. RESULTS CETP mass ranged from 1.29 to 2.95 mg/l. No significant differences in (changes) in mean arterial pressure, aldosterone and active plasma renin concentration in response to low sodium were observed between the lowest and highest tertiles of CETP mass, HDL-C and apolipoprotein A-I. These outcome variables were also not significantly correlated with CETP, HDL-C and apolipoprotein A-I, except for a modest relation of aldosterone measured during low sodium with apolipoprotein A-I (r = 0.28, p = 0.022). Blood pressure response to angiotensin-II was similar between CETP tertiles. CONCLUSIONS Mineralocorticoid and blood pressure responsiveness to dietary salt intake are not significantly related to physiological interindividual differences in plasma CETP. We suggest that a lower CETP mass does not exert adverse effects on blood pressure regulation.
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Affiliation(s)
- Jan A Krikken
- University of Groningen, University Medical Center Groningen, Department of Nephrology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
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20
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Kopprasch S, Pietzsch J, Ansurudeen I, Graessler J, Krug AW, Ehrhart-Bornstein M, Bornstein SR. Prediabetic and diabetic in vivo modification of circulating low-density lipoprotein attenuates its stimulatory effect on adrenal aldosterone and cortisol secretion. J Endocrinol 2009; 200:45-52. [PMID: 18835979 DOI: 10.1677/joe-08-0293] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Modification of low-density lipoprotein (LDL) and abnormal aldosterone and cortisol metabolism have been implicated in the pathogenesis of type 2 diabetes (DM2) and diabetic vascular disease. Since LDL serves as a major cholesterol source for adrenal steroidogenesis, we investigated whether LDL modification in prediabetic and diabetic subjects influences adrenocortical aldosterone and cortisol release. LDL was isolated from 30 subjects with normal glucose tolerance (NGT-LDL), 30 subjects with impaired glucose tolerance (IGT-LDL), and 26 patients with DM2 (DM2-LDL). Oxidation and glycoxidation characteristics of LDL apolipoprotein B100 of each individual was assessed by gas chromatography-mass spectrometry analysis. Human adrenocortical cells (NCI-H295R) were incubated for 24 h with 100 microg/ml LDL and after removal of supernatants stimulated for a further 24 h with angiotensin II (AngII). In supernatants, aldosterone and cortisol secretion was measured. IGT-LDL and DM2-LDL were substantially more modified than NGT-LDL. Each of the five measured oxidation/glycoxidation markers was significantly positively associated with glycemic control, measured as HbA(1c). LDL from all subjects stimulated both the basal and AngII-induced aldosterone and cortisol release from adrenocortical cells. However, hormone secretion was significantly inversely related to the degree of LDL oxidation/glycoxidation. We conclude that LDL modifications in IGT and DM2 subjects may have significant clinical benefits by counteracting prediabetic and diabetic overactivity of the renin-angiotensin-aldosterone system and enhanced cortisol generation.
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Affiliation(s)
- Steffi Kopprasch
- Department of Internal Medicine 3, Pathological Biochemistry, Carl Gustav Carus Medical School, University of Technology Dresden, Dresden, Germany.
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Chang HW, Wu VC, Huang CY, Huang HY, Chen YM, Chu TS, Wu KD, Hsieh BS. D4 dopamine receptor enhances angiotensin II-stimulated aldosterone secretion through PKC-epsilon and calcium signaling. Am J Physiol Endocrinol Metab 2008; 294:E622-9. [PMID: 18171914 DOI: 10.1152/ajpendo.00657.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aldosterone secretion is subjected to dopaminergic regulation. Our previous study showed that both human D2 and D4 dopamine receptors (D2R and D4R) modulate aldosterone secretion, but in opposing directions. The inhibitory effect of D2R is mediated by attenuating protein kinase C-micro (PKC-micro) and calcium-dependent signaling. The mechanism of D4R effect on angiotensin II (AII)-stimulated aldosterone secretion is explored in this study. Experiments were done with primary human adrenal cortical cells and human adrenocarcinoma (NCI-H295R) cells. Activation of different PKC isoforms was detected by specific phospho-PKC antibodies and PKC translocation. The role of calcium-dependent signaling was examined by measuring the cytoplasmic inositol 1,4,5-triphosphate (IP(3)) and calcium ([Ca(2+)](i)). The D4R agonist PD-168,077 enhanced AII-stimulated aldosterone synthesis and secretion as early as 30 min following exposure independently of the modulation of aldosterone synthase (CYP11B2) transcription. CYP11B2 mRNA level elevated by AII was augmented by D4R in the later period. These effects were reversed by the D4R antagonist L-745,870. AII activated PKC-alpha/betaII, -epsilon, and -micro but not PKC-delta, -theta, or -zeta/lambda of H295R cells. The D4R agonist selectively enhanced AII-stimulated PKC-epsilon phosphorylation and its translocation to the cell membrane. Furthermore, the D4R agonist enhanced the AII-stimulated elevation of intracellular IP(3) and [Ca(2+)](i). Inhibition of PKC-epsilon translocation by the PKC-epsilon-specific inhibitory peptide attenuated AII-stimulated aldosterone secretion, CYP11B2 mRNA expression, and elevation of intracellular IP(3) and [Ca(2+)](i). We conclude that D4R augmented aldosterone synthesis/secretion induced by AII. The mechanisms responsible for this augmentation are mediated through enhancing PKC-epsilon phosphorylation and [Ca(2+)](i) elevation.
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Affiliation(s)
- Hong-Wei Chang
- Nephrology Division, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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22
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Liang F, Kapoun AM, Lam A, Damm DL, Quan D, O'Connell M, Protter AA. B-Type natriuretic peptide inhibited angiotensin II-stimulated cholesterol biosynthesis, cholesterol transfer, and steroidogenesis in primary human adrenocortical cells. Endocrinology 2007; 148:3722-9. [PMID: 17478552 DOI: 10.1210/en.2006-1599] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study, we demonstrate that B-type natriuretic peptide (BNP) opposed angiotensin II (Ang II)-stimulated de novo cholesterol biosynthesis, cellular cholesterol uptake, cholesterol transfer to the inner mitochondrial membrane, and steroidogenesis, which are required for biosynthesis of steroid hormones such as aldosterone and cortisol in primary human adrenocortical cells. BNP dose-dependently stimulated intracellular cGMP production with an EC(50) of 11 nm, implying that human adrenocortical cells express the guanylyl cyclase A receptor. cDNA microarray and real-time RT-PCR analyses revealed that BNP inhibited Ang II-stimulated genes related to cholesterol biosynthesis (acetoacetyl coenzyme A thiolase, HMG coenzyme A synthase 1, HMG coenzyme A reductase, isopentenyl-diphosphate Delta-isomerase, lanosterol synthase, sterol-4C-methyl oxidase, and emopamil binding protein/sterol isomerase), cholesterol uptake from circulating lipoproteins (scavenger receptor class B type I and low-density lipoprotein receptor), cholesterol transfer to the inner mitochondrial membrane (steroidogenic acute regulatory protein), and steroidogenesis (ferredoxin 1,3beta-hydroxysteroid dehydrogenase, glutathione transferase A3, CYP19A1, CYP11B1, and CYP11B2). Consistent with the microarray and real-time PCR results, BNP also blocked Ang II-induced binding of (125)I-labeled low-density lipoprotein and (125)I-labeled high-density lipoprotein to human adrenocortical cells. Furthermore, BNP markedly inhibited Ang II-stimulated release of estradiol, aldosterone, and cortisol from cultured primary human adrenocortical cells. These findings demonstrate that BNP opposes Ang II-induced steroidogenesis via multiple steps from cholesterol supply and transfer to the final formation of steroid hormones. This study provides new insights into the cellular mechanisms by which BNP modulates Ang II-induced steroidogenesis in the adrenal gland.
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Affiliation(s)
- Faquan Liang
- Scios Inc., 6500 Paseo Padre Parkway, Fremont, California 94555, USA
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23
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Hwang GS, Wang SW, Tseng WM, Yu CH, Wang PS. Effect of hypoxia on the release of vascular endothelial growth factor and testosterone in mouse TM3 Leydig cells. Am J Physiol Endocrinol Metab 2007; 292:E1763-9. [PMID: 17374694 DOI: 10.1152/ajpendo.00611.2006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hypoxia has been shown to stimulate the expression of vascular endothelial growth factor (VEGF), which is a major mediator for angiogenesis and vasculogenesis. During hypoxia, VEGF promotes angiogenesis in the testis. However, the effect of VEGF on the steroidogenesis of testosterone and the cell proliferation in Leydig cells is unclear. To assess the effects and the action mechanisms of hypoxia, a mouse TM3 Leydig cell line was employed in the present study. The Leydig cells were incubated in an incubator chamber (95% N2-5% CO2) for 1-24 h. The cultured media were collected and assayed by testosterone RIA and VEGF enzyme immunoassay. 3-(4,50-Dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide assay was used to detect the proliferation of Leydig cells. The present results showed that the proliferation of Leydig cells was enhanced significantly by hypoxia. The basal VEGF release was increased, and the response of VEGF production to human chorionic gonadotropin (hCG) was also enhanced in hypoxic condition. During hypoxia, administration of hCG or VEGF stimulated proliferation of Leydig cells, but the stimulatory effect was abolished by the administration of anti-VEGF antibody. Higher doses of VEGF stimulated testosterone release in a dose-dependent manner. Administration of anti-VEGF antibody abolished the stimulatory effect of VEGF on testosterone release. These data suggest that hypoxia stimulates cell proliferation and testosterone release in Leydig cells via an increase of VEGF production.
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Affiliation(s)
- Guey-Shyang Hwang
- Department of Physiology, School of Medicine, National Yang-Ming Univ, Taipei 11221, Taiwan, Republic of China
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Manna PR, Chandrala SP, King SR, Jo Y, Counis R, Huhtaniemi IT, Stocco DM. Molecular Mechanisms of Insulin-like Growth Factor-I Mediated Regulation of the Steroidogenic Acute Regulatory Protein in Mouse Leydig Cells. Mol Endocrinol 2006; 20:362-78. [PMID: 16166197 DOI: 10.1210/me.2004-0526] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Growth factors are known to play diverse roles in steroidogenesis, a process regulated by the mitochondrial steroidogenic acute regulatory (StAR) protein. The mechanism of action of one such growth factor, IGF-I, was investigated in mouse Leydig tumor (mLTC-1) cells to determine its potential role in the regulation of StAR expression. mLTC-1 cells treated with IGF-I demonstrated temporal and concentration-dependent increases in StAR expression and steroid synthesis. However, IGF-I had no effect on cytochrome P450 side-chain cleavage or 3beta-hydroxysteroid dehydrogenase protein levels. IGF-I was capable of augmenting N,O'-dibutyrl-cAMP-stimulated steroidogenic responsiveness in these cells. The steroidogenic potential of IGF-I was also confirmed in primary cultures of isolated mouse Leydig cells. IGF-I increased phosphorylation of ERK1/2, an event inhibited by the MAPK/ERK inhibitors, PD98059 and U0126. Interestingly, inhibition of ERK activity enhanced IGF-I-mediated StAR protein expression, but phosphorylation of StAR was undetectable, an observation in contrast to that seen with N,O'-dibutyrl-cAMP signaling. Further studies demonstrated that these events were tightly correlated with the expression of dosage-sensitive sex reversal, adrenal hypoplasia congenita, critical region on the X chromosome, gene 1 and scavenger receptor class B type 1. Whereas both protein kinase A and protein kinase C signaling were involved in the IGF-I-mediated steroidogenic response, the majority of the effects of IGF-I were found to be mediated by the protein kinase C pathway. Transcriptional activation of the StAR gene by IGF-I was influenced by several transcription factors, its up-regulation being dependent on phosphorylation of the cAMP response element-binding protein (CREB) and the activator protein 1 family member, c-Jun. Conversely, StAR gene transcription was markedly inhibited by expression of nonphosphorylatable CREB (Ser(133)Ala), dominant negative A-CREB, and dominant negative c-Jun (TAM-67) mutants. Collectively, the present studies identify molecular events in IGF-I signaling that may influence testicular growth, development, and the Leydig cell steroidogenic machinery through autocrine/paracrine regulation.
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Affiliation(s)
- Pulak R Manna
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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Abstract
Scavenger receptor class B, type I (SR-BI) is the receptor for high density lipoprotein (HDL) that mediates cellular uptake of HDL cholesteryl ester (CE) and is a major route for cholesterol delivery to steroidogenic pathways. SR-BI is localized in specialized microvillar channel plasma membrane compartments that retain HDL and are sites for HDL CE selective uptake. In fact, adrenal gland microvillar channel formation is regulated by adrenocorticotropin hormone and requires SR-BI expression. SR-BI-mediated uptake of HDL CE is a two-step process requiring high affinity HDL binding followed by transfer of CE to the membrane. SR-BI delivers HDL CE to sites in the membrane where it is readily metabolized to free cholesterol by cell type-specific neutral CE hydrolases. The most likely candidate for the hydrolysis of HDL CE delivered via SR-BI in the adrenal gland is hormone sensitive lipase. New data in adrenocortical cells as well as the study of a mutant SR-BI receptor lend insight into the mechanism of cholesterol transfer from plasma HDL to the steroidogenic pathway in endocrine cells.
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Affiliation(s)
- Margery A Connelly
- Department of Pharmacological Sciences, University Medical Center, State University of New York at Stony Brook, Stony Brook, NY 11794-8651, USA.
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26
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Abstract
Scavenger receptor class B, type I (SR-BI) is a receptor for high-density lipoprotein (HDL) that mediates cellular uptake of HDL cholesteryl ester (HDL CE) and is the major route for cholesterol delivery to the steroidogenic pathway. SR-BI is localized in specialized microvillar channels in the plasma membrane that retain HDL and are sites of selective uptake of HDL CE. The formation of microvillar channels in the adrenal gland requires SR-BI and is regulated by adrenocorticotropin hormone. SR-BI-mediated uptake of HDL CE is a two-step process that requires high-affinity binding of HDL followed by transfer of CE to the membrane. CE uptake is followed by hydrolysis to free cholesterol by a neutral CE hydrolase. In this review, we describe new information on the mechanism of transfer of cholesterol from plasma HDL to the steroidogenic pathway in endocrine cells.
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Affiliation(s)
- Margery A Connelly
- Department of Pharmacological Sciences, University Medical Center, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA
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