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Huo C, Liu Y, Li X, Xu R, Jia X, Hou L, Wang X. LRRC8A contributes to angiotensin II-induced cardiac hypertrophy by interacting with NADPH oxidases via the C-terminal leucine-rich repeat domain. Free Radic Biol Med 2021; 165:191-202. [PMID: 33515753 DOI: 10.1016/j.freeradbiomed.2021.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/08/2021] [Accepted: 01/10/2021] [Indexed: 12/22/2022]
Abstract
Cardiac hypertrophy, an important cause of heart failure, is characterized by an increase in heart weight, the ventricular wall, and cardiomyocyte volume. The volume regulatory anion channel (VRAC) is an important regulator of cell volume. However, its role in cardiac hypertrophy remains unclear. The purpose of this study was to investigate the effect of leucine-rich repeat-containing 8A (LRRC8A), an essential component of the VRAC, on angiotensin II (AngII)-induced cardiac hypertrophy. Our results showed that LRRC8A expression, NADPH oxidase activity, and reactive oxygen species (ROS) production were increased in AngII-induced hypertrophic neonatal mouse cardiomyocytes and the myocardium of C57/BL/6 mice. In addition, AngII activated VRAC currents in cardiomyocytes. The delivery of adeno-associated viral (AAV9) bearing siRNA against mouse LRRC8A into the left ventricular wall inhibited AngII-induced cardiac hypertrophy and fibrosis. Accordingly, the knockdown of LRRC8A attenuated AngII-induced cardiomyocyte hypertrophy and VRAC currents in vitro. Furthermore, knockdown of LRRC8A suppressed AngII-induced ROS production, NADPH oxidase activity, the expression of NADPH oxidase membrane-bound subunits Nox2, Nox4, and p22phox, and the translocation of NADPH oxidase cytosolic subunits p47phox and p67phox. Immunofluorescent staining showed that LRRC8A co-localized with NADPH oxidase membrane subunits Nox2, Nox4, and p22phox. Co-immunoprecipitation and analysis of a C-terminal leucine-rich repeat domain (LRRD) mutant showed that LRRC8A physically interacts with Nox2, Nox4, and p22phox via the LRRD. Taken together, the results of this study suggested that LRRC8A might play an important role in promoting AngII-induced cardiac hypertrophy by interacting with NADPH oxidases via the LRRD.
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Affiliation(s)
- Cong Huo
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Yan Liu
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Xing Li
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Rong Xu
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Xin Jia
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Liming Hou
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Xiaoming Wang
- Department of Geriatrics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China.
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Platt CD, Chou J, Houlihan P, Badran YR, Kumar L, Bainter W, Poliani PL, Perez CJ, Dent SYR, Clapham DE, Benavides F, Geha RS. Leucine-rich repeat containing 8A (LRRC8A)-dependent volume-regulated anion channel activity is dispensable for T-cell development and function. J Allergy Clin Immunol 2017; 140:1651-1659.e1. [PMID: 28192143 DOI: 10.1016/j.jaci.2016.12.974] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 11/20/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Leucine-rich repeat containing 8A (LRRC8A) is an ubiquitously expressed transmembrane protein with 17 leucine-rich repeats (LRRs) at its C-terminal end and is an essential component of the volume-regulated anion channel (VRAC), which controls cellular volume. A heterozygous mutation in LRRC8A that truncates the 2 terminal LRRs was reported in a patient with agammaglobulinemia and absent B cells and was demonstrated to exert a dominant negative effect on T- and B-cell development in mice. Lrrc8a-/- mice have severely defective T-cell development and function. It is not known whether the T- and B-cell defects caused by LRRC8A deficiency are caused by loss of VRAC activity. OBJECTIVE We sought to determine whether VRAC activity is required for normal T-cell development and function. METHODS VRAC activity was examined by using patch-clamp analysis. Flow cytometry was used to examine T-cell development. T-cell proliferation, cytokine secretion, and antibody titers were measured by using standard techniques. RESULTS We demonstrate that the spontaneous mouse mutant ébouriffé (ebo/ebo) harbors a homozygous 2-bp frameshift mutation in Lrrc8a that truncates the 15 terminal LRRs of LRRC8A. The Lrrc8aebo mutation does not affect protein expression but drastically diminishes VRAC activity in T cells. ebo/ebo mice share features with Lrrc8a-/- mice that include curly hair, infertility, reduced longevity, and kidney abnormalities. However, in contrast to Lrrc8a-/- mice, ebo/ebo mice have normal T-cell development and function and intact antibody response to T-dependent antigen. CONCLUSION LRRC8A-dependent VRAC activity is dispensable for T-cell development and function.
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Affiliation(s)
- Craig D Platt
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Janet Chou
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Patrick Houlihan
- Department of Cardiology, Boston Children's Hospital, Boston, Mass
| | - Yousef R Badran
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Lalit Kumar
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - Wayne Bainter
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass
| | - P Luigi Poliani
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Carlos J Perez
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex
| | - Sharon Y R Dent
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex
| | - David E Clapham
- Department of Cardiology, Boston Children's Hospital, Boston, Mass; Howard Hughes Medical Institute, Chevy Chase, Md
| | - Fernando Benavides
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas M. D. Anderson Cancer Center, Smithville, and the Graduate School of Biomedical Sciences at Houston, Houston, Tex
| | - Raif S Geha
- Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Mass.
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