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Huo JY, Sun AP, Zhang XY, Fu Y, Fan DS. [Inflammatory myopathy associated with anti-mitochondrial antibodies: a case report]. Zhonghua Nei Ke Za Zhi 2024; 63:415-418. [PMID: 38561289 DOI: 10.3760/cma.j.cn112138-20231028-00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Affiliation(s)
- J Y Huo
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - A P Sun
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - X Y Zhang
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - Y Fu
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
| | - D S Fan
- Department of Neurology, Peking University Third Hospital, Beijing 100191, China
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Huo JY, Feng YL, Chen YT, Yang B, Zhi YT, Wang HJ, Yang HQ. Caveolin-3 negatively regulates endocytic recycling of cardiac K ATP channels. Am J Physiol Cell Physiol 2023; 325:C1106-C1118. [PMID: 37746698 DOI: 10.1152/ajpcell.00266.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023]
Abstract
Sarcolemmal ATP-sensitive potassium (KATP) channels play a vital role in cardioprotection. Cardiac KATP channels are enriched in caveolae and physically interact with the caveolae structural protein caveolin-3 (Cav3). Disrupting caveolae impairs the regulation of KATP channels through several signaling pathways. However, the direct functional effect of Cav3 on KATP channels is still poorly understood. Here, we used the cardiac KATP channel subtype, Kir6.2/SUR2A, and showed that Cav3 greatly reduced KATP channel surface density and current amplitude in a caveolae-independent manner. A screen of Cav3 functional domains revealed that a 25 amino acid region in the membrane attachment domain of Cav3 is the minimal effective segment (MAD1). The peptide corresponding to the MAD1 segment decreased KATP channel current in a concentration-dependent manner with an IC50 of ∼5 μM. The MAD1 segment prevented KATP channel recycling, thus decreasing KATP channel surface density and abolishing the cardioprotective effect of ischemic preconditioning. Our research identified the Cav3 MAD1 segment as a novel negative regulator of KATP channel recycling, providing pharmacological potential in the treatment of diseases with KATP channel trafficking defects.NEW & NOTEWORTHY Cardiac KATP channels physically interact with caveolin-3 in caveolae. In this study, we investigated the functional effect of caveolin-3 on KATP channel activity and identified a novel segment (MAD1) in the C-terminus domain of Caveolin-3 that negatively regulates KATP channel surface density and current amplitude by impairing KATP channel recycling. The peptide corresponding to the MAD1 segment abolished the cardioprotective effect of ischemic preconditioning.
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Affiliation(s)
- Jian-Yi Huo
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Yu-Long Feng
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Yue-Tong Chen
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Bo Yang
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Ya-Ting Zhi
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Hao-Jie Wang
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
| | - Hua-Qian Yang
- Cyrus Tang Medical Institute, Soochow University, Suzhou, China
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Tuncay E, Gando I, Huo JY, Yepuri G, Samper N, Turan B, Yang HQ, Ramasamy R, Coetzee WA. The cardioprotective role of sirtuins is mediated in part by regulating K ATP channel surface expression. Am J Physiol Cell Physiol 2023; 324:C1017-C1027. [PMID: 36878847 PMCID: PMC10110703 DOI: 10.1152/ajpcell.00459.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/24/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023]
Abstract
Sirtuins are NAD+-dependent deacetylases with beneficial roles in conditions relevant to human health, including metabolic disease, type II diabetes, obesity, cancer, aging, neurodegenerative diseases, and cardiac ischemia. Since ATP-sensitive K+ (KATP) channels have cardioprotective roles, we investigated whether they are regulated by sirtuins. Nicotinamide mononucleotide (NMN) was used to increase cytosolic NAD+ levels and to activate sirtuins in cell lines, isolated rat and mouse cardiomyocytes or insulin-secreting INS-1 cells. KATP channels were studied with patch clamping, biochemistry techniques, and antibody uptake experiments. NMN led to an increase in intracellular NAD+ levels and an increase in the KATP channel current, without significant changes in the unitary current amplitude or open probability. An increased surface expression was confirmed using surface biotinylation approaches. The rate of KATP channel internalization was diminished by NMN, which may be a partial explanation for the increased surface expression. We show that NMN acts via sirtuins since the increased KATP channel surface expression was prevented by blockers of SIRT1 and SIRT2 (Ex527 and AGK2) and mimicked by SIRT1 activation (SRT1720). The pathophysiological relevance of this finding was studied using a cardioprotection assay with isolated ventricular myocytes, in which NMN protected against simulated ischemia or hypoxia in a KATP channel-dependent manner. Overall, our data draw a link between intracellular NAD+, sirtuin activation, KATP channel surface expression, and cardiac protection against ischemic damage.
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Affiliation(s)
- Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Ivan Gando
- Department of Pathology, New York University Grossman Medical Center, New York, New York, United States
| | - Jian-Yi Huo
- Cyrus Tang Hematology Center, Soochow University, Suzhou, People's Republic of China
| | - Gautham Yepuri
- Department of Medicine, New York University Grossman Medical Center, New York, New York, United States
| | - Natalie Samper
- Department of Pathology, New York University Grossman Medical Center, New York, New York, United States
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey
| | - Hua-Qian Yang
- Cyrus Tang Hematology Center, Soochow University, Suzhou, People's Republic of China
| | - Ravichandran Ramasamy
- Department of Medicine, New York University Grossman Medical Center, New York, New York, United States
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman Medical Center, New York, New York, United States
| | - William A Coetzee
- Department of Pathology, New York University Grossman Medical Center, New York, New York, United States
- Department of Physiology & Neuroscience, New York University Grossman Medical Center, New York, New York, United States
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman Medical Center, New York, New York, United States
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Yang B, Yao JL, Huo JY, Feng YL, Coetzee WA, Xu GY, Yang HQ. Rab35 GTPase positively regulates endocytic recycling of cardiac K ATP channels. Channels (Austin) 2022; 16:137-147. [PMID: 35754325 DOI: 10.1080/19336950.2022.2090667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
ATP-sensitive K+ (KATP) channel couples membrane excitability to intracellular energy metabolism. Maintaining KATP channel surface expression is key to normal insulin secretion, blood pressure and cardioprotection. However, the molecular mechanisms regulating KATP channel internalization and endocytic recycling, which directly affect the surface expression of KATP channels, are poorly understood. Here we used the cardiac KATP channel subtype, Kir6.2/SUR2A, and characterized Rab35 GTPase as a key regulator of KATP channel endocytic recycling. Electrophysiological recordings and surface biotinylation assays showed decreased KATP channel surface density with co-expression of a dominant negative Rab35 mutant (Rab35-DN), but not other recycling-related Rab GTPases, including Rab4, Rab11a and Rab11b. Immunofluorescence images revealed strong colocalization of Rab35-DN with recycling Kir6.2. Rab35-DN minimized the recycling rate of KATP channels. Rab35 also regulated KATP channel current amplitude in isolated adult cardiomyocytes by affecting its surface expression but not channel properties, which validated its physiologic relevance and the potential of pharmacologic target for treating the diseases with KATP channel trafficking defects.
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Affiliation(s)
- Bo Yang
- Cyrus Tang Medical Institute, Soochow University, Suzhou, Jiangsu, China
| | - Jia-Lu Yao
- Department of Cardiology, the First Affiliated Hospital of Soochow University, Soochow University, Suzhou, Jiangsu, China.,Department of Cardiology, Dushu Lake Hospital Affiliated to Soochow University, Medical Center of Soochow University, Suzhou Dushu Lake Hospital, Suzhou, Jiangsu, China
| | - Jian-Yi Huo
- Cyrus Tang Medical Institute, Soochow University, Suzhou, Jiangsu, China
| | - Yu-Long Feng
- Cyrus Tang Medical Institute, Soochow University, Suzhou, Jiangsu, China
| | - William A Coetzee
- Departments of Pathology, Neuroscience & Physiology, Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Guang-Yin Xu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases, Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China.,Center for Translational Medicine, The Affiliated Zhangjiagang Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Hua-Qian Yang
- Cyrus Tang Medical Institute, Soochow University, Suzhou, Jiangsu, China
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