1
|
Bose HS, Whittal RM, Marshall B, Rajapaksha M, Wang NP, Bose M, Perry EW, Zhao ZQ, Miller WL. A Novel Mitochondrial Complex of Aldosterone Synthase, Steroidogenic Acute Regulatory Protein, and Tom22 Synthesizes Aldosterone in the Rat Heart. J Pharmacol Exp Ther 2021; 377:108-120. [PMID: 33526603 DOI: 10.1124/jpet.120.000365] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/25/2021] [Indexed: 12/14/2022] Open
Abstract
Aldosterone, which regulates renal salt retention, is synthesized in adrenocortical mitochondria in response to angiotensin II. Excess aldosterone causes myocardial injury and heart failure, but potential intracardiac aldosterone synthesis has been controversial. We hypothesized that the stressed heart might produce aldosterone. We used blue native gel electrophoresis, immunoblotting, protein crosslinking, coimmunoprecipitations, and mass spectrometry to assess rat cardiac aldosterone synthesis. Chronic infusion of angiotensin II increased circulating corticosterone levels 350-fold and induced cardiac fibrosis. Angiotensin II doubled and telmisartan inhibited aldosterone synthesis by heart mitochondria and cardiac production of aldosterone synthase (P450c11AS). Heart aldosterone synthesis required P450c11AS, Tom22 (a mitochondrial translocase receptor), and the intramitochondrial form of the steroidogenic acute regulatory protein (StAR); protein crosslinking and coimmunoprecipitation studies showed that these three proteins form a 110-kDa complex. In steroidogenic cells, extramitochondrial (37-kDa) StAR promotes cholesterol movement from the outer to inner mitochondrial membrane where cholesterol side-chain cleavage enzyme (P450scc) converts cholesterol to pregnenolone, thus initiating steroidogenesis, but no function has previously been ascribed to intramitochondrial (30-kDa) StAR; our data indicate that intramitochondrial 30-kDa StAR is required for aldosterone synthesis in the heart, forming a trimolecular complex with Tom22 and P450c11AS. This is the first activity ascribed to intramitochondrial StAR, but how this promotes P450c11AS activity is unclear. The stressed heart did not express P450scc, suggesting that circulating corticosterone (rather than intracellular cholesterol) is the substrate for cardiac aldosterone synthesis. Thus, the stressed heart produced aldosterone using a previously undescribed intramitochondrial mechanism that involves P450c11AS, Tom22, and 30-kDa StAR. SIGNIFICANCE STATEMENT: Prior studies of potential cardiac aldosterone synthesis have been inconsistent. This study shows that the stressed rat heart produces aldosterone by a novel mechanism involving aldosterone synthase, Tom22, and intramitochondrial steroidogenic acute regulatory protein (StAR) apparently using circulating corticosterone as substrate. This study establishes that the stressed rat heart produces aldosterone and for the first time identifies a biological role for intramitochondrial 30-kDa StAR.
Collapse
Affiliation(s)
- Himangshu S Bose
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Randy M Whittal
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Brendan Marshall
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Maheshinie Rajapaksha
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Ning Ping Wang
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Madhuchanda Bose
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Elizabeth W Perry
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Zhi-Qing Zhao
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| | - Walter L Miller
- Biomedical Sciences, Mercer University School of Medicine, Savannah, Georgia (H.S.B., M.R., N.P.W., Z.-Q.Z.); Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada (R.M.W.); Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Georgia (B.M., E.W.P.); Curtiss Healthcare, University of Florida Innovate Sid Martin Biotechbology Incubator, Gainesville, Florida (M.B.); Anderson Cancer Institute, Savannah, Georgia (H.S.B.); and Department of Pediatrics and Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (W.L.M.)
| |
Collapse
|
2
|
Zhang WW, Zheng RH, Bai F, Sturdivant K, Wang NP, James EA, Bose HS, Zhao ZQ. Steroidogenic acute regulatory protein/aldosterone synthase mediates angiotensin II-induced cardiac fibrosis and hypertrophy. Mol Biol Rep 2019; 47:1207-1222. [PMID: 31820314 DOI: 10.1007/s11033-019-05222-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/22/2019] [Accepted: 12/04/2019] [Indexed: 02/07/2023]
Abstract
Aldosterone produced in adrenal glands by angiotensin II (Ang II) is known to elicit myocardial fibrosis and hypertrophy. This study was designed to test the hypothesis that Ang II causes cardiac morphological changes through the steroidogenic acute regulatory protein (StAR)/aldosterone synthase (AS)-dependent aldosterone synthesis primarily initiated in the heart. Sprague-Dawley rats were randomized to following groups: Ang II infusion for a 4-week period, treatment with telmisartan, spironolactone or adrenalectomy during Ang II infusion. Sham-operated rats served as control. Relative to Sham rats, Ang II infusion significantly increased the protein levels of AT1 receptor, StAR, AS and their tissue expression in the adrenal glands and heart. In coincidence with reduced aldosterone level in the heart, telmisartan, an AT1 receptor blocker, significantly down-regulated the protein level and expression of StAR and AS. Ang II induced changes in the expression of AT1/StAR/AS were not altered by an aldosterone receptor antagonist spironolactone. Furthermore, Ang II augmented migration of macrophages, protein level of TGFβ1, phosphorylation of Smad2/3 and proliferation of myofibroblasts, accompanied by enhanced perivascular/interstitial collagen deposition and cardiomyocyte hypertrophy, which all were significantly abrogated by telmisartan or spironolactone. However, adrenalectomy did not fully suppress Ang II-induced cell migration/proliferation and fibrosis/hypertrophy, indicating a role of aldosterone synthesized within the heart in pathogenesis of Ang II induced injury. These results indicate that myocardial fibrosis and hypertrophy stimulated by Ang II is associated with tissue-specific activation of aldosterone synthesis, primarily mediated by AT1/StAR/AS signaling pathways.
Collapse
Affiliation(s)
- Wei-Wei Zhang
- Department of Basic Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
- Department of Anesthesiology, Shanxi Provincial People's Hospital, Taiyuan, Shanxi, China
| | - Rong-Hua Zheng
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Feng Bai
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, China
| | - Katelyn Sturdivant
- Department of Basic Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Ning-Ping Wang
- Department of Basic Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Erskine A James
- Department of Internal Medicine, Navicent Health, Macon, GA, USA
| | - Himangshu S Bose
- Department of Basic Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA
| | - Zhi-Qing Zhao
- Department of Basic Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA.
- Department of Physiology, Shanxi Medical University, Taiyuan, Shanxi, China.
- Cardiovascular Research Laboratory, Mercer University School of Medicine, 1250 East 66th Street, Savannah, GA, 31404, USA.
| |
Collapse
|