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Chen Q, Li L, Samidurai A, Thompson J, Hu Y, Willard B, Lesnefsky EJ. Acute endoplasmic reticulum stress-induced mitochondria respiratory chain damage: The role of activated calpains. FASEB J 2024; 38:e23404. [PMID: 38197290 PMCID: PMC11032170 DOI: 10.1096/fj.202301158rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 11/19/2023] [Accepted: 12/19/2023] [Indexed: 01/11/2024]
Abstract
The induction of acute endoplasmic reticulum (ER) stress damages the electron transport chain (ETC) in cardiac mitochondria. Activation of mitochondria-localized calpain 1 (CPN1) and calpain 2 (CPN2) impairs the ETC in pathological conditions, including aging and ischemia-reperfusion in settings where ER stress is increased. We asked if the activation of calpains causes the damage to the ETC during ER stress. Control littermate and CPNS1 (calpain small regulatory subunit 1) deletion mice were used in the current study. CPNS1 is an essential subunit required to maintain CPN1 and CPN2 activities, and deletion of CPNS1 prevents their activation. Tunicamycin (TUNI, 0.4 mg/kg) was used to induce ER stress in C57BL/6 mice. Cardiac mitochondria were isolated after 72 h of TUNI treatment. ER stress was increased in both control littermate and CPNS1 deletion mice with TUNI treatment. The TUNI treatment activated both cytosolic and mitochondrial CPN1 and 2 (CPN1/2) in control but not in CPNS1 deletion mice. TUNI treatment led to decreased oxidative phosphorylation and complex I activity in control but not in CPNS1 deletion mice compared to vehicle. The contents of complex I subunits, including NDUFV2 and ND5, were decreased in control but not in CPNS1 deletion mice. TUNI treatment also led to decreased oxidation through cytochrome oxidase (COX) only in control mice. Proteomic study showed that subunit 2 of COX was decreased in control but not in CPNS1 deletion mice. Our results provide a direct link between activation of CPN1/2 and complex I and COX damage during acute ER stress.
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Affiliation(s)
- Qun Chen
- Department of Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ling Li
- Proteomics Core, Cleveland Clinic, Cleveland, Ohio, USA
| | - Arun Samidurai
- Department of Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jeremy Thompson
- Department of Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ying Hu
- Department of Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA
| | | | - Edward J. Lesnefsky
- Department of Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, USA
- Richmond Department of Veterans Affairs Medical Center, Richmond, Virginia, USA
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Liu F, Liu Z, Cheng W, Zhao Q, Zhang X, Zhang H, Yu M, Xu H, Gao Y, Jiang Q, Shi G, Wang L, Gu S, Wang J, Cao N, Chen Z. The PERK Branch of the Unfolded Protein Response Safeguards Protein Homeostasis and Mesendoderm Specification of Human Pluripotent Stem Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303799. [PMID: 37890465 PMCID: PMC10724406 DOI: 10.1002/advs.202303799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 08/14/2023] [Indexed: 10/29/2023]
Abstract
Cardiac development involves large-scale rearrangements of the proteome. How the developing cardiac cells maintain the integrity of the proteome during the rapid lineage transition remains unclear. Here it is shown that proteotoxic stress visualized by the misfolded and/or aggregated proteins appears during early cardiac differentiation of human pluripotent stem cells and is resolved by activation of the PERK branch of unfolded protein response (UPR). PERK depletion increases misfolded and/or aggregated protein accumulation, leading to pluripotency exit defect and impaired mesendoderm specification of human pluripotent stem cells. Mechanistically, it is found that PERK safeguards mesendoderm specification through its conserved downstream effector ATF4, which subsequently activates a novel transcriptional target WARS1, to cope with the differentiation-induced proteotoxic stress. The results indicate that protein quality control represents a previously unrecognized core component of the cardiogenic regulatory network. Broadly, these findings provide a framework for understanding how UPR is integrated into the developmental program by activating the PERK-ATF4-WARS1 axis.
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Affiliation(s)
- Fang Liu
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
- Department of Clinical LaboratoryThe First Affiliated Hospital of Anhui Medical UniversityHefei230022P. R. China
| | - Zhun Liu
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Weisheng Cheng
- Prenatal Diagnosis CenterDepartment of Obstetrics and GynecologyThe First Affiliated Hospital of Anhui Medical UniversityHefei230022P. R. China
- Department of Medical InformaticsZhongshan School of MedicineSun Yat‐Sen UniversityGuangzhou510080P. R. China
| | - Qingquan Zhao
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Xinyu Zhang
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - He Zhang
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Miao Yu
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - He Xu
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Yichen Gao
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Qianrui Jiang
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Guojun Shi
- Guangzhou Municipal Key Laboratory of Mechanistic and Translational Obesity ResearchGuangdong Provincial Key Laboratory of DiabetologyThe Third Affiliated Hospital of Sun Yat‐Sen UniversityGuangdong510080P. R. China
| | - Likun Wang
- National Laboratory of BiomacromoleculesCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing100101P. R. China
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijing100049P. R. China
| | - Shanshan Gu
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Jia Wang
- School of Health and Life SciencesUniversity of Health and Rehabilitation SciencesShandong266071China
| | - Nan Cao
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
| | - Zhongyan Chen
- Advanced Medical Technology CenterZhongshan School of Medicine and the First Affiliated HospitalSun Yat‐Sen UniversityGuangzhou510080P. R. China
- Key Laboratory for Stem Cells and Tissue EngineeringSun Yat‐Sen UniversityMinistry of EducationGuangzhou510080P. R. China
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Glembotski CC, Bagchi S, Blackwood EA. ER-Specific Autophagy or ER-Phagy in Cardiac Myocytes Protects the Heart Against Doxorubicin-Induced Cardiotoxicity. JACC CardioOncol 2023; 5:671-673. [PMID: 37969647 PMCID: PMC10635872 DOI: 10.1016/j.jaccao.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023] Open
Affiliation(s)
- Christopher C. Glembotski
- Translational Cardiovascular Research Center and the Department of Internal Medicine, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA
| | - Sukriti Bagchi
- Translational Cardiovascular Research Center and the Department of Internal Medicine, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA
| | - Erik A. Blackwood
- Translational Cardiovascular Research Center and the Department of Internal Medicine, University of Arizona College of Medicine-Phoenix, Phoenix, Arizona, USA
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Thareja SK, Anfinson M, Cavanaugh M, Kim MS, Lamberton P, Radandt J, Brown R, Liang HL, Stamm K, Afzal MZ, Strande J, Frommelt MA, Lough JW, Fitts RH, Mitchell ME, Tomita-Mitchell A. Altered contractility, Ca 2+ transients, and cell morphology seen in a patient-specific iPSC-CM model of Ebstein's anomaly with left ventricular noncompaction. Am J Physiol Heart Circ Physiol 2023; 325:H149-H162. [PMID: 37204873 PMCID: PMC10312315 DOI: 10.1152/ajpheart.00658.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/15/2023] [Accepted: 05/15/2023] [Indexed: 05/21/2023]
Abstract
Patients with two congenital heart diseases (CHDs), Ebstein's anomaly (EA) and left ventricular noncompaction (LVNC), suffer higher morbidity than either CHD alone. The genetic etiology and pathogenesis of combined EA/LVNC remain largely unknown. We investigated a familial EA/LVNC case associated with a variant (p.R237C) in the gene encoding Kelch-like protein 26 (KLHL26) by differentiating induced pluripotent stem cells (iPSCs) generated from affected and unaffected family members into cardiomyocytes (iPSC-CMs) and assessing iPSC-CM morphology, function, gene expression, and protein abundance. Compared with unaffected iPSC-CMs, CMs containing the KLHL26 (p.R237C) variant exhibited aberrant morphology including distended endo(sarco)plasmic reticulum (ER/SR) and dysmorphic mitochondria and aberrant function that included decreased contractions per minute, altered calcium transients, and increased proliferation. Pathway enrichment analyses based on RNASeq data indicated that the "structural constituent of muscle" pathway was suppressed, whereas the "ER lumen" pathway was activated. Taken together, these findings suggest that iPSC-CMs containing this KLHL26 (p.R237C) variant develop dysregulated ER/SR, calcium signaling, contractility, and proliferation.NEW & NOTEWORTHY We demonstrate here that iPSCs derived from patients with Ebstein's anomaly and left ventricular noncompaction, when differentiated into cardiomyocytes, display significant structural and functional changes that offer insight into disease pathogenesis, including altered ER/SR and mitochondrial morphology, contractility, and calcium signaling.
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Affiliation(s)
- Suma K Thareja
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Melissa Anfinson
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Matthew Cavanaugh
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Min-Su Kim
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Peter Lamberton
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Jackson Radandt
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Ryan Brown
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Huan-Ling Liang
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Karl Stamm
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Muhammad Zeeshan Afzal
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jennifer Strande
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michele A Frommelt
- Division of Pediatric Cardiology, Department of Pediatrics, Children's Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
| | - John W Lough
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Michael E Mitchell
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
| | - Aoy Tomita-Mitchell
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
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Secretion of functional α1-antitrypsin is cell type dependent: Implications for intramuscular delivery for gene therapy. Proc Natl Acad Sci U S A 2022; 119:e2206103119. [PMID: 35901208 PMCID: PMC9351467 DOI: 10.1073/pnas.2206103119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Heterologous expression of proteins is used widely for the biosynthesis of biologics, many of which are secreted from cells. In addition, gene therapy and messenger RNA (mRNA) vaccines frequently direct the expression of secretory proteins to nonnative host cells. Consequently, it is crucial to understand the maturation and trafficking of proteins in a range of host cells including muscle cells, a popular therapeutic target due to the ease of accessibility by intramuscular injection. Here, we analyzed the production efficiency for α1-antitrypsin (AAT) in Chinese hamster ovary cells, commonly used for biotherapeutic production, and myoblasts (embryonic progenitor cells of muscle cells) and compared it to the production in the major natural cells, liver hepatocytes. AAT is a target protein for gene therapy to address pathologies associated with insufficiencies in native AAT activity or production. AAT secretion and maturation were most efficient in hepatocytes. Myoblasts were the poorest of the cell types tested; however, secretion of active AAT was significantly augmented in myoblasts by treatment with the proteostasis regulator suberoylanilide hydroxamic acid, a histone deacetylase inhibitor. These findings were extended and validated in myotubes (mature muscle cells) where AAT was transduced using an adeno-associated viral capsid transduction method used in gene therapy clinical trials. Overall, our study sheds light on a possible mechanism to enhance the efficacy of gene therapy approaches for AAT and, moreover, may have implications for the production of proteins from mRNA vaccines, which rely on the expression of viral glycoproteins in nonnative host cells upon intramuscular injection.
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Mariángelo JIE, Valverde CA, Vittone L, Said M, Mundiña-Weilenmann C. Pharmacological inhibition of translocon is sufficient to alleviate endoplasmic reticulum stress and improve Ca 2+ handling and contractile recovery of stunned myocardium. Eur J Pharmacol 2022; 914:174665. [PMID: 34861208 DOI: 10.1016/j.ejphar.2021.174665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/13/2021] [Accepted: 11/29/2021] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The function of endoplasmic reticulum (ER), a Ca2+ storage compartment and site of protein folding, is altered by disruption of intracellular homeostasis. Misfolded proteins accumulated in the ER lead to ER stress (ERS), unfolded protein response (UPR) activation and ER Ca2+ loss. Myocardial stunning is a temporary contractile dysfunction, which occurs after brief ischemic periods with minimal or no cell death, being oxidative stress and Ca2+ overload potential underlying mechanisms. Myocardial stunning induces ERS response with negatively impact on the post-ischemic mechanical performance through an unknown mechanism. AIMS In this study, we explored whether ER Ca2+ efflux through the translocon, a major Ca2+ leak channel, contributes to Ca2+ mishandling and the consequent contractile abnormalities of the stunned myocardium. METHODS Mechanical performance, cytosolic Ca2+, UPR markers and oxidative state were evaluated in perfused rat/mouse hearts subjected to a brief ischemia followed by reperfusion (I/R) in absence or presence of the translocon inhibitor, emetine (1 μM), comparing its effects with those of the chaperones TUDCA (30 μM) and 4-PBA (3 mM). RESULTS Emetine treatment precluded the I/R-induced increase in UPR signaling markers and improved the contractile recovery together with a remarkable attenuation in myocardial stiffness when compared to I/R hearts with no drug. This alleviation of I/R-induced mechanical abnormalities was more effective than that obtained with the chemical chaperones, TUDCA and 4-PBA. Moreover, emetine treatment produced a striking improvement in diastolic Ca2+ handling with a partial recovery of the I/R-induced oxidative stress. CONCLUSION Blocking ER Ca2+ store depletion via translocon suppressed ER stress and improved mechanical performance and diastolic Ca2+ handling of stunned myocardium. Modulation of translocon permeability emerges as a therapeutic approach to face dysfunctional consequences of the I/R injury.
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Affiliation(s)
- Juan Ignacio Elio Mariángelo
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Carlos Alfredo Valverde
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Leticia Vittone
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Matilde Said
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Cecilia Mundiña-Weilenmann
- Centro de Investigaciones Cardiovasculares, CCT-CONICET La Plata, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
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Distributed synthesis of sarcolemmal and sarcoplasmic reticulum membrane proteins in cardiac myocytes. Basic Res Cardiol 2021; 116:63. [PMID: 34713358 PMCID: PMC8553722 DOI: 10.1007/s00395-021-00895-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/30/2021] [Accepted: 09/11/2021] [Indexed: 02/05/2023]
Abstract
It is widely assumed that synthesis of membrane proteins, particularly in the heart, follows the classical secretory pathway with mRNA translation occurring in perinuclear regions followed by protein trafficking to sites of deployment. However, this view is based on studies conducted in less-specialized cells, and has not been experimentally addressed in cardiac myocytes. Therefore, we undertook direct experimental investigation of protein synthesis in cardiac tissue and isolated myocytes using single-molecule visualization techniques and a novel proximity-ligated in situ hybridization approach for visualizing ribosome-associated mRNA molecules for a specific protein species, indicative of translation sites. We identify here, for the first time, that the molecular machinery for membrane protein synthesis occurs throughout the cardiac myocyte, and enables distributed synthesis of membrane proteins within sub-cellular niches where the synthesized protein functions using local mRNA pools trafficked, in part, by microtubules. We also observed cell-wide distribution of membrane protein mRNA in myocardial tissue from both non-failing and hypertrophied (failing) human hearts, demonstrating an evolutionarily conserved distributed mechanism from mouse to human. Our results identify previously unanticipated aspects of local control of cardiac myocyte biology and highlight local protein synthesis in cardiac myocytes as an important potential determinant of the heart’s biology in health and disease.
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Evangelisti A, Butler H, del Monte F. The Heart of the Alzheimer's: A Mindful View of Heart Disease. Front Physiol 2021; 11:625974. [PMID: 33584340 PMCID: PMC7873884 DOI: 10.3389/fphys.2020.625974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Purpose of Review: This review summarizes the current evidence for the involvement of proteotoxicity and protein quality control systems defects in diseases of the central nervous and cardiovascular systems. Specifically, it presents the commonalities between the pathophysiology of protein misfolding diseases in the heart and the brain. Recent Findings: The involvement of protein homeostasis dysfunction has been for long time investigated and accepted as one of the leading pathophysiological causes of neurodegenerative diseases. In cardiovascular diseases instead the mechanistic focus had been on the primary role of Ca2+ dishomeostasis, myofilament dysfunction as well as extracellular fibrosis, whereas no attention was given to misfolding of proteins as a pathogenetic mechanism. Instead, in the recent years, several contributions have shown protein aggregates in failing hearts similar to the ones found in the brain and increasing evidence have highlighted the crucial importance that proteotoxicity exerts via pre-amyloidogenic species in cardiovascular diseases as well as the prominent role of the cellular response to misfolded protein accumulation. As a result, proteotoxicity, unfolding protein response (UPR), and ubiquitin-proteasome system (UPS) have recently been investigated as potential key pathogenic pathways and therapeutic targets for heart disease. Summary: Overall, the current knowledge summarized in this review describes how the misfolding process in the brain parallels in the heart. Understanding the folding and unfolding mechanisms involved early through studies in the heart will provide new knowledge for neurodegenerative proteinopathies and may prepare the stage for targeted and personalized interventions.
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Affiliation(s)
| | - Helen Butler
- School of Medicine, Department of Molecular and Cellular Biology and Pathobiology, Medical University of South Carolina, Charleston, SC, United States
| | - Federica del Monte
- Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
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9
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Arrieta A, Blackwood EA, Stauffer WT, Santo Domingo M, Bilal AS, Thuerauf DJ, Pentoney AN, Aivati C, Sarakki AV, Doroudgar S, Glembotski CC. Mesencephalic astrocyte-derived neurotrophic factor is an ER-resident chaperone that protects against reductive stress in the heart. J Biol Chem 2020; 295:7566-7583. [PMID: 32327487 DOI: 10.1074/jbc.ra120.013345] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
We have previously demonstrated that ischemia/reperfusion (I/R) impairs endoplasmic reticulum (ER)-based protein folding in the heart and thereby activates an unfolded protein response sensor and effector, activated transcription factor 6α (ATF6). ATF6 then induces mesencephalic astrocyte-derived neurotrophic factor (MANF), an ER-resident protein with no known structural homologs and unclear ER function. To determine MANF's function in the heart in vivo, here we developed a cardiomyocyte-specific MANF-knockdown mouse model. MANF knockdown increased cardiac damage after I/R, which was reversed by AAV9-mediated ectopic MANF expression. Mechanistically, MANF knockdown in cultured neonatal rat ventricular myocytes (NRVMs) impaired protein folding in the ER and cardiomyocyte viability during simulated I/R. However, this was not due to MANF-mediated protection from reactive oxygen species generated during reperfusion. Because I/R impairs oxygen-dependent ER protein disulfide formation and such impairment can be caused by reductive stress in the ER, we examined the effects of the reductive ER stressor DTT. MANF knockdown in NRVMs increased cell death from DTT-mediated reductive ER stress, but not from nonreductive ER stresses caused by thapsigargin-mediated ER Ca2+ depletion or tunicamycin-mediated inhibition of ER protein glycosylation. In vitro, recombinant MANF exhibited chaperone activity that depended on its conserved cysteine residues. Moreover, in cells, MANF bound to a model ER protein exhibiting improper disulfide bond formation during reductive ER stress but did not bind to this protein during nonreductive ER stress. We conclude that MANF is an ER chaperone that enhances protein folding and myocyte viability during reductive ER stress.
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Affiliation(s)
- Adrian Arrieta
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Erik A Blackwood
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Winston T Stauffer
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Michelle Santo Domingo
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Alina S Bilal
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Donna J Thuerauf
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Amber N Pentoney
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Cathrine Aivati
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Anup V Sarakki
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
| | - Shirin Doroudgar
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA.,Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Innere Medizin III, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christopher C Glembotski
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, California, USA
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10
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Glembotski CC, Arrieta A, Blackwood EA, Stauffer WT. ATF6 as a Nodal Regulator of Proteostasis in the Heart. Front Physiol 2020; 11:267. [PMID: 32322217 PMCID: PMC7156617 DOI: 10.3389/fphys.2020.00267] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022] Open
Abstract
Proteostasis encompasses a homeostatic cellular network in all cells that maintains the integrity of the proteome, which is critical for optimal cellular function. The components of the proteostasis network include protein synthesis, folding, trafficking, and degradation. Cardiac myocytes have a specialized endoplasmic reticulum (ER) called the sarcoplasmic reticulum that is well known for its role in contractile calcium handling. However, less studied is the proteostasis network associated with the ER, which is of particular importance in cardiac myocytes because it ensures the integrity of proteins that are critical for cardiac contraction, e.g., ion channels, as well as proteins necessary for maintaining myocyte viability and interaction with other cell types, e.g., secreted hormones and growth factors. A major aspect of the ER proteostasis network is the ER unfolded protein response (UPR), which is initiated when misfolded proteins in the ER activate a group of three ER transmembrane proteins, one of which is the transcription factor, ATF6. Prior to studies in the heart, ATF6 had been shown in model cell lines to be primarily adaptive, exerting protective effects by inducing genes that encode ER proteins that fortify protein-folding in this organelle, thus establishing the canonical role for ATF6. Subsequent studies in isolated cardiac myocytes and in the myocardium, in vivo, have expanded roles for ATF6 beyond the canonical functions to include the induction of genes that encode proteins outside of the ER that do not have known functions that are obviously related to ER protein-folding. The identification of such non-canonical roles for ATF6, as well as findings that the gene programs induced by ATF6 differ depending on the stimulus, have piqued interest in further research on ATF6 as an adaptive effector in cardiac myocytes, underscoring the therapeutic potential of activating ATF6 in the heart. Moreover, discoveries of small molecule activators of ATF6 that adaptively affect the heart, as well as other organs, in vivo, have expanded the potential for development of ATF6-based therapeutics. This review focuses on the ATF6 arm of the ER UPR and its effects on the proteostasis network in the myocardium.
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Affiliation(s)
- Christopher C Glembotski
- Department of Biology, College of Sciences, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Adrian Arrieta
- Department of Biology, College of Sciences, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Erik A Blackwood
- Department of Biology, College of Sciences, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Winston T Stauffer
- Department of Biology, College of Sciences, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
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Designing Novel Therapies to Mend Broken Hearts: ATF6 and Cardiac Proteostasis. Cells 2020; 9:cells9030602. [PMID: 32138230 PMCID: PMC7140506 DOI: 10.3390/cells9030602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 02/28/2020] [Indexed: 12/12/2022] Open
Abstract
The heart exhibits incredible plasticity in response to both environmental and genetic alterations that affect workload. Over the course of development, or in response to physiological or pathological stimuli, the heart responds to fluctuations in workload by hypertrophic growth primarily by individual cardiac myocytes growing in size. Cardiac hypertrophy is associated with an increase in protein synthesis, which must coordinate with protein folding and degradation to allow for homeostatic growth without affecting the functional integrity of cardiac myocytes (i.e., proteostasis). This increase in the protein folding demand in the growing cardiac myocyte activates the transcription factor, ATF6 (activating transcription factor 6α, an inducer of genes that restore proteostasis. Previously, ATF6 has been shown to induce ER-targeted proteins functioning primarily to enhance ER protein folding and degradation. More recent studies, however, have illuminated adaptive roles for ATF6 functioning outside of the ER by inducing non-canonical targets in a stimulus-specific manner. This unique ability of ATF6 to act as an initial adaptive responder has bolstered an enthusiasm for identifying small molecule activators of ATF6 and similar proteostasis-based therapeutics.
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12
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Stauffer WT, Blackwood EA, Azizi K, Kaufman RJ, Glembotski CC. The ER Unfolded Protein Response Effector, ATF6, Reduces Cardiac Fibrosis and Decreases Activation of Cardiac Fibroblasts. Int J Mol Sci 2020; 21:ijms21041373. [PMID: 32085622 PMCID: PMC7073073 DOI: 10.3390/ijms21041373] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/06/2020] [Accepted: 02/14/2020] [Indexed: 02/06/2023] Open
Abstract
Activating transcription factor-6 α (ATF6) is one of the three main sensors and effectors of the endoplasmic reticulum (ER) stress response and, as such, it is critical for protecting the heart and other tissues from a variety of environmental insults and disease states. In the heart, ATF6 has been shown to protect cardiac myocytes. However, its roles in other cell types in the heart are unknown. Here we show that ATF6 decreases the activation of cardiac fibroblasts in response to the cytokine, transforming growth factor β (TGFβ), which can induce fibroblast trans-differentiation into a myofibroblast phenotype through signaling via the TGFβ–Smad pathway. ATF6 activation suppressed fibroblast contraction and the induction of α smooth muscle actin (αSMA). Conversely, fibroblasts were hyperactivated when ATF6 was silenced or deleted. ATF6 thus represents a novel inhibitor of the TGFβ–Smad axis of cardiac fibroblast activation.
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Affiliation(s)
- Winston T. Stauffer
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.T.S.); (E.A.B.); (K.A.)
| | - Erik A. Blackwood
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.T.S.); (E.A.B.); (K.A.)
| | - Khalid Azizi
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.T.S.); (E.A.B.); (K.A.)
| | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA;
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92161, USA
| | - Christopher C. Glembotski
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA 92182, USA; (W.T.S.); (E.A.B.); (K.A.)
- Correspondence: ; Tel.: +1-619-594-2958
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13
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Arrieta A, Blackwood EA, Stauffer WT, Glembotski CC. Integrating ER and Mitochondrial Proteostasis in the Healthy and Diseased Heart. Front Cardiovasc Med 2020; 6:193. [PMID: 32010709 PMCID: PMC6974444 DOI: 10.3389/fcvm.2019.00193] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
The integrity of the proteome in cardiac myocytes is critical for robust heart function. Proteome integrity in all cells is managed by protein homeostasis or proteostasis, which encompasses processes that maintain the balance of protein synthesis, folding, and degradation in ways that allow cells to adapt to conditions that present a potential challenge to viability (1). While there are processes in various cellular locations in cardiac myocytes that contribute to proteostasis, those in the cytosol, mitochondria and endoplasmic reticulum (ER) have dominant roles in maintaining cardiac contractile function. Cytosolic proteostasis has been reviewed elsewhere (2, 3); accordingly, this review focuses on proteostasis in the ER and mitochondria, and how they might influence each other and, thus, impact heart function in the settings of cardiac physiology and disease.
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Affiliation(s)
- Adrian Arrieta
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Erik A Blackwood
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Winston T Stauffer
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
| | - Christopher C Glembotski
- Department of Biology, San Diego State University Heart Institute, San Diego State University, San Diego, CA, United States
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14
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Blackwood EA, Hofmann C, Santo Domingo M, Bilal AS, Sarakki A, Stauffer W, Arrieta A, Thuerauf DJ, Kolkhorst FW, Müller OJ, Jakobi T, Dieterich C, Katus HA, Doroudgar S, Glembotski CC. ATF6 Regulates Cardiac Hypertrophy by Transcriptional Induction of the mTORC1 Activator, Rheb. Circ Res 2019; 124:79-93. [PMID: 30582446 DOI: 10.1161/circresaha.118.313854] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Endoplasmic reticulum (ER) stress dysregulates ER proteostasis, which activates the transcription factor, ATF6 (activating transcription factor 6α), an inducer of genes that enhance protein folding and restore ER proteostasis. Because of increased protein synthesis, it is possible that protein folding and ER proteostasis are challenged during cardiac myocyte growth. However, it is not known whether ATF6 is activated, and if so, what its function is during hypertrophic growth of cardiac myocytes. OBJECTIVE To examine the activity and function of ATF6 during cardiac hypertrophy. METHODS AND RESULTS We found that ER stress and ATF6 were activated and ATF6 target genes were induced in mice subjected to an acute model of transverse aortic constriction, or to free-wheel exercise, both of which promote adaptive cardiac myocyte hypertrophy with preserved cardiac function. Cardiac myocyte-specific deletion of Atf6 (ATF6 cKO [conditional knockout]) blunted transverse aortic constriction and exercise-induced cardiac myocyte hypertrophy and impaired cardiac function, demonstrating a role for ATF6 in compensatory myocyte growth. Transcript profiling and chromatin immunoprecipitation identified RHEB (Ras homologue enriched in brain) as an ATF6 target gene in the heart. RHEB is an activator of mTORC1 (mammalian/mechanistic target of rapamycin complex 1), a major inducer of protein synthesis and subsequent cell growth. Both transverse aortic constriction and exercise upregulated RHEB, activated mTORC1, and induced cardiac hypertrophy in wild type mouse hearts but not in ATF6 cKO hearts. Mechanistically, knockdown of ATF6 in neonatal rat ventricular myocytes blocked phenylephrine- and IGF1 (insulin-like growth factor 1)-mediated RHEB induction, mTORC1 activation, and myocyte growth, all of which were restored by ectopic RHEB expression. Moreover, adeno-associated virus 9- RHEB restored cardiac growth to ATF6 cKO mice subjected to transverse aortic constriction. Finally, ATF6 induced RHEB in response to growth factors, but not in response to other activators of ATF6 that do not induce growth, indicating that ATF6 target gene induction is stress specific. CONCLUSIONS Compensatory cardiac hypertrophy activates ER stress and ATF6, which induces RHEB and activates mTORC1. Thus, ATF6 is a previously unrecognized link between growth stimuli and mTORC1-mediated cardiac growth.
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Affiliation(s)
- Erik A Blackwood
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Christoph Hofmann
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.).,Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.)
| | - Michelle Santo Domingo
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Alina S Bilal
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Anup Sarakki
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Winston Stauffer
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Adrian Arrieta
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Donna J Thuerauf
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Fred W Kolkhorst
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
| | - Oliver J Müller
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.).,Department of Internal Medicine III, University of Kiel, Germany, and German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Germany (O.J.M.)
| | - Tobias Jakobi
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.).,Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III, University Hospital Heidelberg, Germany (T.J., C.D.)
| | - Christoph Dieterich
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.).,Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III, University Hospital Heidelberg, Germany (T.J., C.D.)
| | - Hugo A Katus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.)
| | - Shirin Doroudgar
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., O.J.M., H.A.K., S.D.).,German Centre for Cardiovascular Research, Partner Site Heidelberg (C.H., O.J.M., T.J., C.D., H.A.K., S.D.)
| | - Christopher C Glembotski
- From the Department of Biology, San Diego State University Heart Institute, San Diego State University, CA (E.A.B., C.H., M.S.D., A.S.B., A.S., W.S., A.A., D.J.T., F.W.K., C.C.G.)
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15
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Nanoscale reorganization of sarcoplasmic reticulum in pressure-overload cardiac hypertrophy visualized by dSTORM. Sci Rep 2019; 9:7867. [PMID: 31133706 PMCID: PMC6536555 DOI: 10.1038/s41598-019-44331-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 05/15/2019] [Indexed: 02/06/2023] Open
Abstract
Pathological cardiac hypertrophy is a debilitating condition characterized by deleterious thickening of the myocardium, dysregulated Ca2+ signaling within cardiomyocytes, and contractile dysfunction. Importantly, the nanoscale organization, localization, and patterns of expression of critical Ca2+ handling regulators including dihydropyridine receptor (DHPR), ryanodine receptor 2 (RyR2), phospholamban (PLN), and sarco/endoplasmic reticulum Ca2+-ATPase 2A (SERCA2A) remain poorly understood, especially during pathological hypertrophy disease progression. In the current study, we induced cardiac pathological hypertrophy via transverse aortic constriction (TAC) on 8-week-old CD1 mice, followed by isolation of cardiac ventricular myocytes. dSTORM super-resolution imaging was then used to visualize proteins at nanoscale resolution at two time points and we quantified changes in protein cluster properties using Voronoi tessellation and 2D Fast Fourier Transform analyses. We showed a decrease in the density of DHPR and RyR2 clusters with pressure-overload cardiac hypertrophy and an increase in the density of SERCA2A protein clusters. PLN protein clusters decreased in density in 2-week TAC but returned to sham levels by 4-week TAC. Furthermore, 2D-FFT analysis revealed changes in molecular organization during pathological hypertrophy, with DHPR and RyR2 becoming dispersed while both SERCA2A and PLN sequestered into dense clusters. Our work reveals molecular adaptations that occur in critical SR proteins at a single molecule during pressure overload-induced cardiomyopathy. Nanoscale alterations in protein localization and patterns of expression of crucial SR proteins within the cardiomyocyte provided insights into the pathogenesis of cardiac hypertrophy, and specific evidence that cardiomyocytes undergo significant structural remodeling during the progression of pathological hypertrophy.
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16
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Abstract
More than four decades passed since sigma receptors were first mentioned. Since then, existence of at least two receptor subtypes and their tissue distributions have been proposed. Nowadays, it is clear, that sigma receptors are unique ubiquitous proteins with pluripotent function, which can interact with so many different classes of proteins. As the endoplasmic resident proteins, they work as molecular chaperones - accompany various proteins during their folding, ensure trafficking of the maturated proteins between cellular organelles and regulate their functions. In the heart, sigma receptor type 1 is more dominant. Cardiac sigma 1 receptors regulate response to endoplasmic reticulum stress, modulates calcium signaling in cardiomyocyte and can affect function of voltage-gated ion channels. They contributed in pathophysiology of cardiac hypertrophy, heart failure and many other cardiovascular disorders. Therefore, sigma receptors are potential novel targets for specific treatment of cardiovascular diseases.
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Affiliation(s)
- T Stracina
- Department of Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
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17
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Network pharmacology-based identification of major component of Angelica sinensis and its action mechanism for the treatment of acute myocardial infarction. Biosci Rep 2018; 38:BSR20180519. [PMID: 30232231 PMCID: PMC6239257 DOI: 10.1042/bsr20180519] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 01/06/2023] Open
Abstract
Background: To decipher the mechanisms of Angelica sinensis for the treatment of acute myocardial infarction (AMI) using network pharmacology analysis. Methods: Databases were searched for the information on constituents, targets, and diseases. Cytoscape software was used to construct the constituent–target–disease network and screen the major targets, which were annotated with the DAVID (Database for Annotation, Visualization and Integrated Discovery) tool. The cardioprotective effects of Angelica sinensis polysaccharide (ASP), a major component of A. sinensis, were validated both in H9c2 cells subjected to simulated ischemia by oxygen and glucose deprivation and in rats with AMI by ligation of the left anterior coronary artery. Results: We identified 228 major targets against AMI injury for A. sinensis, which regulated multiple pathways and hit multiple targets involved in several biological processes. ASP significantly decreased endoplasmic reticulum (ER) stress-induced cell death both in vitro and in vivo. In ischemia injury rats, ASP treatment reduced infarct size and preserved heart function. ASP enhanced activating transcription factor 6 (ATF6) activity, which improved ER-protein folding capacity. ASP activated the expression of p-AMP-activated protein kinase (p-AMPK) and peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α). Additionally, ASP attenuated levels of proinflammatory cytokines and maintained a balance in the oxidant/antioxidant levels after AMI. Conclusion:In silico analysis revealed the associations between A. sinensis and AMI through multiple targets and several key signaling pathways. Experimental data indicate that ASP protects the heart against ischemic injury by activating ATF6 to ameliorate the detrimental ER stress. ASP’s effects could be mediated via the activation of AMPK-PGC1α pathway.
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18
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Hu C, Tian Y, Xu H, Pan B, Terpstra EM, Wu P, Wang H, Li F, Liu J, Wang X. Inadequate ubiquitination-proteasome coupling contributes to myocardial ischemia-reperfusion injury. J Clin Invest 2018; 128:5294-5306. [PMID: 30204128 DOI: 10.1172/jci98287] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 09/04/2018] [Indexed: 12/14/2022] Open
Abstract
The ubiquitin-proteasome system (UPS) degrades a protein molecule via 2 main steps: ubiquitination and proteasomal degradation. Extraproteasomal ubiquitin receptors are thought to couple the 2 steps, but this proposition has not been tested in vivo with vertebrates. More importantly, impaired UPS performance plays a major role in cardiac pathogenesis, including myocardial ischemia-reperfusion injury (IRI), but the molecular basis of UPS impairment remains poorly understood. Ubiquilin1 is a bona fide extraproteasomal ubiquitin receptor. Here, we report that mice with a cardiomyocyte-restricted knockout of Ubiquilin1 (Ubqln1-CKO mice) accumulated a surrogate UPS substrate (GFPdgn) and increased myocardial ubiquitinated proteins without altering proteasome activities, resulting in late-onset cardiomyopathy and a markedly shortened life span. When subject to regional myocardial ischemia-reperfusion, young Ubqln1-CKO mice showed substantially exacerbated cardiac malfunction and enlarged infarct size, and conversely, mice with transgenic Ubqln1 overexpression displayed attenuated IRI. Furthermore, Ubqln1 overexpression facilitated proteasomal degradation of oxidized proteins and the degradation of a UPS surrogate substrate in cultured cardiomyocytes without increasing autophagic flux. These findings demonstrate that Ubiquilin1 is essential to cardiac ubiquitination-proteasome coupling and that an inadequacy in the coupling represents a major pathogenic factor for myocardial IRI; therefore, strategies to strengthen coupling have the potential to reduce IRI.
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Affiliation(s)
- Chengjun Hu
- Department of Human Anatomy, Wuhan University College of Basic Medical Sciences, Wuhan, Hubei, China.,Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Yihao Tian
- Department of Human Anatomy, Wuhan University College of Basic Medical Sciences, Wuhan, Hubei, China.,Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Hongxin Xu
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA.,Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Bo Pan
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Erin M Terpstra
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Penglong Wu
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA.,Protein Modification and Degradation Lab, School of Basic Medical Sciences, Affiliated Tumor Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Hongmin Wang
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
| | - Faqian Li
- Department of Pathology and Laboratory Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jinbao Liu
- Protein Modification and Degradation Lab, School of Basic Medical Sciences, Affiliated Tumor Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xuejun Wang
- Division of Basic Biomedical Sciences, Sanford School of Medicine of the University of South Dakota, Vermillion, South Dakota, USA
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19
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Abstract
Human heart failure is characterized by arrhythmogenic electrical remodeling consisting mostly of ion channel downregulations. Reversing these downregulations is a logical approach to antiarrhythmic therapy, but understanding the pathophysiological mechanisms of the reduced currents is crucial for finding the proper treatments. The unfolded protein response (UPR) is activated by endoplasmic reticulum (ER) stress and has been found to play pivotal roles in different diseases including neurodegenerative diseases, diabetes mellitus, and heart disease. Recently, the UPR is reported to regulate multiple cardiac ion channels, contributing to arrhythmias in heart disease. In this review, we will discuss which UPR modulators and effectors could be involved in regulation of cardiac ion channels in heart disease, and how the understanding of these regulating mechanisms may lead to new antiarrhythmic therapeutics that lack the proarrhythmic risk of current ion channel blocking therapies.
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Affiliation(s)
- Man Liu
- a Division of Cardiology, Department of Medicine, The Lillehei Heart Institute , University of Minnesota at Twin Cities , Minneapolis , USA
| | - Samuel C Dudley
- a Division of Cardiology, Department of Medicine, The Lillehei Heart Institute , University of Minnesota at Twin Cities , Minneapolis , USA
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20
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Ami D, Mereghetti P, Leri M, Giorgetti S, Natalello A, Doglia SM, Stefani M, Bucciantini M. A FTIR microspectroscopy study of the structural and biochemical perturbations induced by natively folded and aggregated transthyretin in HL-1 cardiomyocytes. Sci Rep 2018; 8:12508. [PMID: 30131519 PMCID: PMC6104026 DOI: 10.1038/s41598-018-30995-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/09/2018] [Indexed: 02/07/2023] Open
Abstract
Protein misfolding and aggregation are associated with a number of human degenerative diseases. In spite of the enormous research efforts to develop effective strategies aimed at interfering with the pathogenic cascades induced by misfolded/aggregated peptides/proteins, the necessary detailed understanding of the molecular bases of amyloid formation and toxicity is still lacking. To this aim, approaches able to provide a global insight in amyloid-mediated physiological alterations are of importance. In this study, we exploited Fourier transform infrared microspectroscopy, supported by multivariate analysis, to investigate in situ the spectral changes occurring in cultured intact HL-1 cardiomyocytes exposed to wild type (WT) or mutant (L55P) transthyretin (TTR) in native, or amyloid conformation. The presence of extracellular deposits of amyloid aggregates of WT or L55P TTR, respectively, is a key hallmark of two pathological conditions, known as senile systemic amyloidosis and familial amyloid polyneuropathy. We found that the major effects, associated with modifications in lipid properties and in the cell metabolic/phosphorylation status, were observed when natively folded WT or L55P TTR was administered to the cells. The effects induced by aggregates of TTR were milder and in some cases displayed a different timing compared to those elicited by the natively folded protein.
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Affiliation(s)
- Diletta Ami
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy.
| | - Paolo Mereghetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy
| | - Manuela Leri
- Department of Neuroscience, Psychology, Area of Medicine and Health of the Child of the University of Florence, Viale Pieraccini, 6, 50139, Florence, Italy.,Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale Morgagni 50, 50134, Florence, Italy
| | - Sofia Giorgetti
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Viale Taramelli 3/B, 27100, Pavia, Italy
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy
| | - Silvia Maria Doglia
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milano, Italy
| | - Massimo Stefani
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale Morgagni 50, 50134, Florence, Italy.,Interuniversity Center for the Study of Neurodegenerative Diseases (CIMN), Florence, Italy
| | - Monica Bucciantini
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Viale Morgagni 50, 50134, Florence, Italy. .,Interuniversity Center for the Study of Neurodegenerative Diseases (CIMN), Florence, Italy.
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21
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Gélinas R, Mailleux F, Dontaine J, Bultot L, Demeulder B, Ginion A, Daskalopoulos EP, Esfahani H, Dubois-Deruy E, Lauzier B, Gauthier C, Olson AK, Bouchard B, Des Rosiers C, Viollet B, Sakamoto K, Balligand JL, Vanoverschelde JL, Beauloye C, Horman S, Bertrand L. AMPK activation counteracts cardiac hypertrophy by reducing O-GlcNAcylation. Nat Commun 2018; 9:374. [PMID: 29371602 PMCID: PMC5785516 DOI: 10.1038/s41467-017-02795-4] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 12/28/2017] [Indexed: 12/11/2022] Open
Abstract
AMP-activated protein kinase (AMPK) has been shown to inhibit cardiac hypertrophy. Here, we show that submaximal AMPK activation blocks cardiomyocyte hypertrophy without affecting downstream targets previously suggested to be involved, such as p70 ribosomal S6 protein kinase, calcineurin/nuclear factor of activated T cells (NFAT) and extracellular signal-regulated kinases. Instead, cardiomyocyte hypertrophy is accompanied by increased protein O-GlcNAcylation, which is reversed by AMPK activation. Decreasing O-GlcNAcylation by inhibitors of the glutamine:fructose-6-phosphate aminotransferase (GFAT), blocks cardiomyocyte hypertrophy, mimicking AMPK activation. Conversely, O-GlcNAcylation-inducing agents counteract the anti-hypertrophic effect of AMPK. In vivo, AMPK activation prevents myocardial hypertrophy and the concomitant rise of O-GlcNAcylation in wild-type but not in AMPKα2-deficient mice. Treatment of wild-type mice with O-GlcNAcylation-inducing agents reverses AMPK action. Finally, we demonstrate that AMPK inhibits O-GlcNAcylation by mainly controlling GFAT phosphorylation, thereby reducing O-GlcNAcylation of proteins such as troponin T. We conclude that AMPK activation prevents cardiac hypertrophy predominantly by inhibiting O-GlcNAcylation.
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Affiliation(s)
- Roselle Gélinas
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Florence Mailleux
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Justine Dontaine
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Laurent Bultot
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Bénédicte Demeulder
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Audrey Ginion
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Evangelos P Daskalopoulos
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Hrag Esfahani
- Pole of Pharmacotherapy, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Emilie Dubois-Deruy
- Pole of Pharmacotherapy, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Benjamin Lauzier
- l'institut du thorax, INSERM, CNRS, Univ. Nantes, Nantes, 44007, France
| | - Chantal Gauthier
- l'institut du thorax, INSERM, CNRS, Univ. Nantes, Nantes, 44007, France
| | - Aaron K Olson
- Department of Pediatrics, University of Washington School of Medicine and Seattle Children's Research Institute, Seattle, 98105-0371, WA, USA.,Montreal Heart Institute, Montreal, H1T 1C8, Canada
| | | | - Christine Des Rosiers
- Montreal Heart Institute, Montreal, H1T 1C8, Canada.,Department of Nutrition, Université de Montréal, Montreal, H3T 1A8, Canada
| | - Benoit Viollet
- Institut Cochin, INSERM U1016, 75014, Paris, France.,CNRS UMR8104, 75014, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, 75014, France
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, Lausanne, 1015, Switzerland
| | - Jean-Luc Balligand
- Pole of Pharmacotherapy, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Jean-Louis Vanoverschelde
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium.,Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, 1200, Belgium
| | - Christophe Beauloye
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium.,Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, 1200, Belgium
| | - Sandrine Horman
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium
| | - Luc Bertrand
- Pole of Cardiovascular Research, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, 1200, Belgium.
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22
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Alam S, Abdullah CS, Aishwarya R, Orr AW, Traylor J, Miriyala S, Panchatcharam M, Pattillo CB, Bhuiyan MS. Sigmar1 regulates endoplasmic reticulum stress-induced C/EBP-homologous protein expression in cardiomyocytes. Biosci Rep 2017; 37:BSR20170898. [PMID: 28667101 PMCID: PMC5518542 DOI: 10.1042/bsr20170898] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 01/09/2023] Open
Abstract
C/EBP-homologous protein (CHOP) is a ubiquitously expressed stress-inducible transcription factor robustly induced by maladaptive endoplasmic reticulum (ER) stresses in a wide variety of cells. Here, we examined a novel function of Sigma 1 receptor (Sigmar1) in regulating CHOP expression under ER stress in cardiomyocytes. We also defined Sigmar1-dependent activation of the adaptive ER-stress pathway in regulating CHOP expression. We used adenovirus-mediated Sigmar1 overexpression as well as Sigmar1 knockdown by siRNA in neonatal rat ventricular cardiomyocytes (NRCs); to induce ER stress, cardiomyocytes were treated with tunicamycin. Sigmar1-siRNA knockdown significantly increased the expression of CHOP and significantly induced cellular toxicity by sustained activation of ER stress in cardiomyocytes. Sigmar1 overexpression decreased the expression of CHOP and significantly decreased cellular toxicity in cells. Using biochemical and immunocytochemical experiments, we also defined the specific ER-stress pathway associated with Sigmar1-dependent regulation of CHOP expression and cellular toxicity. We found that Sigmar1 overexpression significantly increased inositol requiring kinase 1α (IRE1α) phosphorylation and increased spliced X-box-binding proteins (XBP1s) expression as well as nuclear localization. In contrast, Sigmar1 knockdown significantly decreased IRE1α phosphorylation and decreased XBP1s expression as well as nuclear transport. Taken together, these results indicate that Sigmar1-dependent activation of IRE1α-XBP1s ER-stress response pathways are associated with inhibition of CHOP expression and suppression of cellular toxicity. Hence, Sigmar1 is an essential component of the adaptive ER-stress response pathways eliciting cellular protection in cardiomyocytes.
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Affiliation(s)
- Shafiul Alam
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Chowdhury S Abdullah
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Richa Aishwarya
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - A Wayne Orr
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - James Traylor
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Sumitra Miriyala
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Manikandan Panchatcharam
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Christopher B Pattillo
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
| | - Md Shenuarin Bhuiyan
- Department of Pathology and Translational Pathobiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A.
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, U.S.A
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23
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Amici DR, Pinal-Fernandez I, Mázala DAG, Lloyd TE, Corse AM, Christopher-Stine L, Mammen AL, Chin ER. Calcium dysregulation, functional calpainopathy, and endoplasmic reticulum stress in sporadic inclusion body myositis. Acta Neuropathol Commun 2017; 5:24. [PMID: 28330496 PMCID: PMC5363023 DOI: 10.1186/s40478-017-0427-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 03/12/2017] [Indexed: 01/08/2023] Open
Abstract
Sporadic inclusion body myositis (IBM) is the most common primary myopathy in the elderly, but its pathoetiology is still unclear. Perturbed myocellular calcium (Ca2+) homeostasis can exacerbate many of the factors proposed to mediate muscle degeneration in IBM, such as mitochondrial dysfunction, protein aggregation, and endoplasmic reticulum stress. Ca2+ dysregulation may plausibly be initiated in IBM by immune-mediated membrane damage and/or abnormally accumulating proteins, but no studies to date have investigated Ca2+ regulation in IBM patients. We first investigated protein expression via immunoblot in muscle biopsies from IBM, dermatomyositis, and non-myositis control patients, identifying several differentially expressed Ca2+-regulatory proteins in IBM. Next, we investigated the Ca2+-signaling transcriptome by RNA-seq, finding 54 of 183 (29.5%) genes from an unbiased list differentially expressed in IBM vs. controls. Using an established statistical approach to relate genes with causal transcription networks, Ca2+ abundance was considered a significant upstream regulator of observed whole-transcriptome changes. Post-hoc analyses of Ca2+-regulatory mRNA and protein data indicated a lower protein to transcript ratio in IBM vs. controls, which we hypothesized may relate to increased Ca2+-dependent proteolysis and decreased protein translation. Supporting this hypothesis, we observed robust (4-fold) elevation in the autolytic activation of a Ca2+-activated protease, calpain-1, as well as increased signaling for translational attenuation (eIF2α phosphorylation) downstream of the unfolded protein response. Finally, in IBM samples we observed mRNA and protein under-expression of calpain-3, the skeletal muscle-specific calpain, which broadly supports proper Ca2+ homeostasis. Together, these data provide novel insight into mechanisms by which intracellular Ca2+ regulation is perturbed in IBM and offer evidence of pathological downstream effects.
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24
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Arrieta A, Blackwood EA, Glembotski CC. ER Protein Quality Control and the Unfolded Protein Response in the Heart. Curr Top Microbiol Immunol 2017; 414:193-213. [PMID: 29026925 DOI: 10.1007/82_2017_54] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cardiac myocytes are the cells responsible for the robust ability of the heart to pump blood throughout the circulatory system. Cardiac myocytes grow in response to a variety of physiological and pathological conditions; this growth challenges endoplasmic reticulum-protein quality control (ER-PQC), a major feature of which includes the unfolded protein response (UPR). ER-PQC and the UPR in cardiac myocytes growing under physiological conditions, including normal development, exercise, and pregnancy, are sufficient to support hypertrophic growth of each cardiac myocyte. However, the ER-PQC and UPR are insufficient to respond to the challenge of cardiac myocyte growth under pathological conditions, including myocardial infarction and heart failure. In part, this insufficiency is due to a continual decline in the expression levels of important adaptive UPR components as a function of age and during myocardial pathology. This chapter will discuss the physiological and pathological conditions unique to the heart that involves ER-PQC, and whether the UPR is adaptive or maladaptive under these circumstances.
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Affiliation(s)
- A Arrieta
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, CA, 92182, USA
| | - E A Blackwood
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, CA, 92182, USA
| | - C C Glembotski
- San Diego State University Heart Institute and the Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
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25
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Jin JK, Blackwood EA, Azizi K, Thuerauf DJ, Fahem AG, Hofmann C, Kaufman RJ, Doroudgar S, Glembotski CC. ATF6 Decreases Myocardial Ischemia/Reperfusion Damage and Links ER Stress and Oxidative Stress Signaling Pathways in the Heart. Circ Res 2016; 120:862-875. [PMID: 27932512 DOI: 10.1161/circresaha.116.310266] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/02/2016] [Accepted: 12/08/2016] [Indexed: 12/14/2022]
Abstract
RATIONALE Endoplasmic reticulum (ER) stress causes the accumulation of misfolded proteins in the ER, activating the transcription factor, ATF6 (activating transcription factor 6 alpha), which induces ER stress response genes. Myocardial ischemia induces the ER stress response; however, neither the function of this response nor whether it is mediated by ATF6 is known. OBJECTIVE Here, we examined the effects of blocking the ATF6-mediated ER stress response on ischemia/reperfusion (I/R) in cardiac myocytes and mouse hearts. METHODS AND RESULTS Knockdown of ATF6 in cardiac myocytes subjected to I/R increased reactive oxygen species and necrotic cell death, both of which were mitigated by ATF6 overexpression. Under nonstressed conditions, wild-type and ATF6 knockout mouse hearts were similar. However, compared with wild-type, ATF6 knockout hearts showed increased damage and decreased function after I/R. Mechanistically, gene array analysis showed that ATF6, which is known to induce genes encoding ER proteins that augment ER protein folding, induced numerous oxidative stress response genes not previously known to be ATF6-inducible. Many of the proteins encoded by the ATF6-induced oxidative stress genes identified here reside outside the ER, including catalase, which is known to decrease damaging reactive oxygen species in the heart. Catalase was induced by the canonical ER stressor, tunicamycin, and by I/R in cardiac myocytes from wild-type but not in cardiac myocytes from ATF6 knockout mice. ER stress response elements were identified in the catalase gene and were shown to bind ATF6 in cardiac myocytes, which increased catalase promoter activity. Overexpression of catalase, in vivo, restored ATF6 knockout mouse heart function to wild-type levels in a mouse model of I/R, as did adeno-associated virus 9-mediated ATF6 overexpression. CONCLUSIONS ATF6 serves an important role as a previously unappreciated link between the ER stress and oxidative stress gene programs, supporting a novel mechanism by which ATF6 decreases myocardial I/R damage.
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Affiliation(s)
- Jung-Kang Jin
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Erik A Blackwood
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Khalid Azizi
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Donna J Thuerauf
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Asal G Fahem
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Christoph Hofmann
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Randal J Kaufman
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Shirin Doroudgar
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.)
| | - Christopher C Glembotski
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (J.-K.J., E.A.B., K.A., D.J.T., A.G.F., C.H., S.D., C.C.G.); Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, Germany (C.H., S.D.); DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany (C.H., S.D.); and Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA (R.J.K.).
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26
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Tse G, Yan BP, Chan YWF, Tian XY, Huang Y. Reactive Oxygen Species, Endoplasmic Reticulum Stress and Mitochondrial Dysfunction: The Link with Cardiac Arrhythmogenesis. Front Physiol 2016; 7:313. [PMID: 27536244 PMCID: PMC4971160 DOI: 10.3389/fphys.2016.00313] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/11/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Cardiac arrhythmias represent a significant problem globally, leading to cerebrovascular accidents, myocardial infarction, and sudden cardiac death. There is increasing evidence to suggest that increased oxidative stress from reactive oxygen species (ROS), which is elevated in conditions such as diabetes and hypertension, can lead to arrhythmogenesis. METHOD A literature review was undertaken to screen for articles that investigated the effects of ROS on cardiac ion channel function, remodeling and arrhythmogenesis. RESULTS Prolonged endoplasmic reticulum stress is observed in heart failure, leading to increased production of ROS. Mitochondrial ROS, which is elevated in diabetes and hypertension, can stimulate its own production in a positive feedback loop, termed ROS-induced ROS release. Together with activation of mitochondrial inner membrane anion channels, it leads to mitochondrial depolarization. Abnormal function of these organelles can then activate downstream signaling pathways, ultimately culminating in altered function or expression of cardiac ion channels responsible for generating the cardiac action potential (AP). Vascular and cardiac endothelial cells become dysfunctional, leading to altered paracrine signaling to influence the electrophysiology of adjacent cardiomyocytes. All of these changes can in turn produce abnormalities in AP repolarization or conduction, thereby increasing likelihood of triggered activity and reentry. CONCLUSION ROS plays a significant role in producing arrhythmic substrate. Therapeutic strategies targeting upstream events include production of a strong reducing environment or the use of pharmacological agents that target organelle-specific proteins and ion channels. These may relieve oxidative stress and in turn prevent arrhythmic complications in patients with diabetes, hypertension, and heart failure.
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Affiliation(s)
- Gary Tse
- Li Ka Shing Faculty of Medicine, School of Biomedical Sciences, University of Hong KongHong Kong, China
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong KongHong Kong, China
| | - Bryan P. Yan
- Department of Medicine and Therapeutics, Faculty of Medicine, Chinese University of Hong KongHong Kong, China
- Department of Epidemiology and Preventive Medicine, Monash UniversityMelbourne, VIC, Australia
| | - Yin W. F. Chan
- Department of Psychology, School of Biological Sciences, University of CambridgeCambridge, UK
| | - Xiao Yu Tian
- Faculty of Medicine, School of Biomedical Sciences, Chinese University of Hong KongHong Kong, China
| | - Yu Huang
- Faculty of Medicine, School of Biomedical Sciences, Chinese University of Hong KongHong Kong, China
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27
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Kollipara L, Buchkremer S, Weis J, Brauers E, Hoss M, Rütten S, Caviedes P, Zahedi RP, Roos A. Proteome Profiling and Ultrastructural Characterization of the Human RCMH Cell Line: Myoblastic Properties and Suitability for Myopathological Studies. J Proteome Res 2016; 15:945-55. [PMID: 26781476 DOI: 10.1021/acs.jproteome.5b00972] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Studying (neuro)muscular disorders is a major topic in biomedicine with a demand for suitable model systems. Continuous cell culture (in vitro) systems have several technical advantages over in vivo systems and became widely used tools for discovering physiological/pathophysiological mechanisms in muscle. In particular, myoblast cell lines are suitable model systems to study complex biochemical adaptations occurring in skeletal muscle and cellular responses to altered genetic/environmental conditions. Whereas most in vitro studies use extensively characterized murine C2C12 cells, a comprehensive description of an equivalent human cell line, not genetically manipulated for immortalization, is lacking. Therefore, we characterized human immortal myoblastic RCMH cells using scanning (SEM) and transmission electron microscopy (TEM) and proteomics. Among more than 6200 identified proteins we confirm the known expression of proteins important for muscle function. Comparing the RCMH proteome with two well-defined nonskeletal muscle cells lines (HeLa, U2OS) revealed a considerable enrichment of proteins important for muscle function. SEM/TEM confirmed the presence of agglomerates of cytoskeletal components/intermediate filaments and a prominent rough ER. In conclusion, our results indicate RMCH as a suitable in vitro model for investigating muscle function-related processes such as mechanical stress burden and mechanotransduction, EC coupling, cytoskeleton, muscle cell metabolism and development, and (ER-associated) myopathic disorders.
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Affiliation(s)
- Laxmikanth Kollipara
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Stephan Buchkremer
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Eva Brauers
- Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
| | - Mareike Hoss
- Electron Microscopic Facility, Institute of Pathology, RWTH Aachen University Hospital , D-52074 Aachen, Germany
| | - Stephan Rütten
- Electron Microscopic Facility, Institute of Pathology, RWTH Aachen University Hospital , D-52074 Aachen, Germany
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile , Santiago 1058, Chile
| | - René P Zahedi
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany
| | - Andreas Roos
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V. , Otto-Hahn-Str. 6b, 44227 Dortmund, Germany.,Institute of Neuropathology, RWTH Aachen University Hospital , Pauwelsstrasse 30, D-52074 Aachen, Germany
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28
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Gupta MK, Tahrir FG, Knezevic T, White MK, Gordon J, Cheung JY, Khalili K, Feldman AM. GRP78 Interacting Partner Bag5 Responds to ER Stress and Protects Cardiomyocytes From ER Stress-Induced Apoptosis. J Cell Biochem 2016; 117:1813-21. [PMID: 26729625 DOI: 10.1002/jcb.25481] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 01/04/2016] [Indexed: 12/12/2022]
Abstract
Bag5 is a member of the BAG family of molecular chaperone regulators and is unusual in that it consists of five BAG domains, which function as modulators of chaperone activity. Bag family proteins play a key role in cellular as well as in cardiac function and their differential expression is reported in heart failure. In this study, we examined the importance of a Bag family member protein, Bag5, in cardiomyocytes during endoplasmic reticulum (ER) stress. We found that expression of Bag5 in cardiomyocytes is significantly increased with the induction of ER stress in a time dependent manner. We have taken gain-in and loss-of functional approaches to characterize Bag5 protein function in cardiomyocytes. Adenoviral mediated expression of Bag5 significantly decreased cell death as well as improved cellular viability in ER stress. Along with this, ER stress-induced CHOP protein expression is significantly decreased in cells that overexpress Bag5. Conversely, we found that siRNA-mediated knockdown of Bag5 caused cell death, increased cytotoxicity, and decreased cellular viability in cardiomyocytes. Mechanistically, we found that Bag5 protein expression is significantly increased in the ER during ER stress and that this in turn modulates GRP78 protein stability and reduces ER stress. This study suggests that Bag5 is an important regulator of ER function and so could be exploited as a tool to improve cardiomyocyte function under stress conditions. J. Cell. Biochem. 117: 1813-1821, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Manish K Gupta
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Farzaneh G Tahrir
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Tijana Knezevic
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania
| | - Martyn K White
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Jennifer Gordon
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Joseph Y Cheung
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
- Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Kamel Khalili
- Department of Neuroscience, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Arthur M Feldman
- Department of Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
- Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
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Brandenburg S, Arakel EC, Schwappach B, Lehnart SE. The molecular and functional identities of atrial cardiomyocytes in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1882-93. [PMID: 26620800 DOI: 10.1016/j.bbamcr.2015.11.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 12/28/2022]
Abstract
Atrial cardiomyocytes are essential for fluid homeostasis, ventricular filling, and survival, yet their cell biology and physiology are incompletely understood. It has become clear that the cell fate of atrial cardiomyocytes depends significantly on transcription programs that might control thousands of differentially expressed genes. Atrial muscle membranes propagate action potentials and activate myofilament force generation, producing overall faster contractions than ventricular muscles. While atria-specific excitation and contractility depend critically on intracellular Ca(2+) signalling, voltage-dependent L-type Ca(2+) channels and ryanodine receptor Ca(2+) release channels are each expressed at high levels similar to ventricles. However, intracellular Ca(2+) transients in atrial cardiomyocytes are markedly heterogeneous and fundamentally different from ventricular cardiomyocytes. In addition, differential atria-specific K(+) channel expression and trafficking confer unique electrophysiological and metabolic properties. Because diseased atria have the propensity to perpetuate fast arrhythmias, we discuss our understanding about the cell-specific mechanisms that lead to metabolic and/or mitochondrial dysfunction in atrial fibrillation. Interestingly, recent work identified potential atria-specific mechanisms that lead to early contractile dysfunction and metabolic remodelling, suggesting highly interdependent metabolic, electrical, and contractile pathomechanisms. Hence, the objective of this review is to provide an integrated model of atrial cardiomyocytes, from tissue-specific cell properties, intracellular metabolism, and excitation-contraction (EC) coupling to early pathological changes, in particular metabolic dysfunction and tissue remodelling due to atrial fibrillation and aging. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Sören Brandenburg
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Eric C Arakel
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - Blanche Schwappach
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Molecular Biology, University Medical Center Göttingen, 37073 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany
| | - Stephan E Lehnart
- Heart Research Center Göttingen, University Medical Center Göttingen, 37075 Göttingen, Germany; Department of Cardiology & Pulmonology, University Medical Center Göttingen, 37075 Göttingen, Germany; German Centre for Cardiovascular Research (DZHK) site Göttingen, 37075 Göttingen, Germany.
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Doroudgar S, Völkers M, Thuerauf DJ, Khan M, Mohsin S, Respress JL, Wang W, Gude N, Müller OJ, Wehrens XHT, Sussman MA, Glembotski CC. Hrd1 and ER-Associated Protein Degradation, ERAD, are Critical Elements of the Adaptive ER Stress Response in Cardiac Myocytes. Circ Res 2015; 117:536-46. [PMID: 26137860 DOI: 10.1161/circresaha.115.306993] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 07/01/2015] [Indexed: 11/16/2022]
Abstract
RATIONALE Hydroxymethyl glutaryl-coenzyme A reductase degradation protein 1 (Hrd1) is an endoplasmic reticulum (ER)-transmembrane E3 ubiquitin ligase that has been studied in yeast, where it contributes to ER protein quality control by ER-associated degradation (ERAD) of misfolded proteins that accumulate during ER stress. Neither Hrd1 nor ERAD has been studied in the heart, or in cardiac myocytes, where protein quality control is critical for proper heart function. OBJECTIVE The objective of this study were to elucidate roles for Hrd1 in ER stress, ERAD, and viability in cultured cardiac myocytes and in the mouse heart, in vivo. METHODS AND RESULTS The effects of small interfering RNA-mediated Hrd1 knockdown were examined in cultured neonatal rat ventricular myocytes. The effects of adeno-associated virus-mediated Hrd1 knockdown and overexpression were examined in the hearts of mice subjected to pressure overload-induced pathological cardiac hypertrophy, which challenges protein-folding capacity. In cardiac myocytes, the ER stressors, thapsigargin and tunicamycin increased ERAD, as well as adaptive ER stress proteins, and minimally affected cell death. However, when Hrd1 was knocked down, thapsigargin and tunicamycin dramatically decreased ERAD, while increasing maladaptive ER stress proteins and cell death. In vivo, Hrd1 knockdown exacerbated cardiac dysfunction and increased apoptosis and cardiac hypertrophy, whereas Hrd1 overexpression preserved cardiac function and decreased apoptosis and attenuated cardiac hypertrophy in the hearts of mice subjected to pressure overload. CONCLUSIONS Hrd1 and ERAD are essential components of the adaptive ER stress response in cardiac myocytes. Hrd1 contributes to preserving heart structure and function in a mouse model of pathological cardiac hypertrophy.
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Affiliation(s)
- Shirin Doroudgar
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Mirko Völkers
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Donna J Thuerauf
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Mohsin Khan
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Sadia Mohsin
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Jonathan L Respress
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Wei Wang
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Natalie Gude
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Oliver J Müller
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Xander H T Wehrens
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Mark A Sussman
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.)
| | - Christopher C Glembotski
- From the San Diego State University Heart Institute and the Department of Biology, San Diego State University, CA (S.D., M.V., D.J.T., M.K., S.M., N.G., M.A.S., C.C.G.); Department of Cardiology, University of Heidelberg, Heidelberg, Germany (M.V.); DZKH (German Centre for Cardiovascular Research) Partner Site Heidelberg/Mannheim, Heidelberg, Germany (M.V.); Department of Internal Medicine III (O.J.M.), University of Heidelberg, Heidelberg, Germany; Center for Translational Medicine, Temple University School of Medicine, Philadelphia, PA (M.K., S.M.); and Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX (J.L.R., W.W., X.H.T.W.).
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Chen D, Wang Y, Chin ER. Activation of the endoplasmic reticulum stress response in skeletal muscle of G93A*SOD1 amyotrophic lateral sclerosis mice. Front Cell Neurosci 2015; 9:170. [PMID: 26041991 PMCID: PMC4435075 DOI: 10.3389/fncel.2015.00170] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 04/16/2015] [Indexed: 12/14/2022] Open
Abstract
Mutations in Cu/Zn superoxide dismutase (SOD1) are one of the genetic causes of Amyotrophic Lateral Sclerosis (ALS). Although the primary symptom of ALS is muscle weakness, the link between SOD1 mutations, cellular dysfunction and muscle atrophy and weakness is not well understood. The purpose of this study was to characterize cellular markers of ER stress in skeletal muscle across the lifespan of G93A*SOD1 (ALS-Tg) mice. Muscles were obtained from ALS-Tg and age-matched wild type (WT) mice at 70d (pre-symptomatic), 90d and 120–140d (symptomatic) and analyzed for ER stress markers. In white gastrocnemius (WG) muscle, ER stress sensors PERK and IRE1α were upregulated ~2-fold at 70d and remained (PERK) or increased further (IRE1α) at 120–140d. Phospho-eIF2α, a downstream target of PERK and an inhibitor of protein translation, was increased by 70d and increased further to 12.9-fold at 120–140d. IRE1α upregulation leads to increased splicing of X-box binding protein 1 (XBP-1) to the XBP-1s isoform. XBP-1s transcript was increased at 90d and 120–140d indicating activation of IRE1α signaling. The ER chaperone/heat shock protein Grp78/BiP was upregulated 2-fold at 70d and 90d and increased to 6.1-fold by 120–140d. The ER-stress-specific apoptotic signaling protein CHOP was upregulated 2-fold at 70d and 90d and increased to 13.3-fold at 120–140d indicating progressive activation of an apoptotic signal in muscle. There was a greater increase in Grp78/BiP and CHOP in WG vs. the more oxidative red gastrocnemius (RG) ALS-Tg at 120–140d indicating greater ER stress and apoptosis in fast glycolytic muscle. These data show that the ER stress response is activated in skeletal muscle of ALS-Tg mice by an early pre-symptomatic age and increases with disease progression. These data suggest a mechanism by which myocellular ER stress leads to reduced protein translation and contributes to muscle atrophy and weakness in ALS.
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Affiliation(s)
- Dapeng Chen
- School of Public Health, University of Maryland MD, USA
| | - Yan Wang
- Proteomics Core Facility, College of Computer, Mathematics and Natural Sciences, University of Maryland MD, USA
| | - Eva R Chin
- School of Public Health, University of Maryland MD, USA
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Glembotski CC. Roles for ATF6 and the sarco/endoplasmic reticulum protein quality control system in the heart. J Mol Cell Cardiol 2013; 71:11-5. [PMID: 24140798 DOI: 10.1016/j.yjmcc.2013.09.018] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 09/26/2013] [Accepted: 09/27/2013] [Indexed: 11/30/2022]
Abstract
The hypertrophic growth of cardiac myocytes is a highly dynamic process that underlies physiological and pathological adaptation of the heart. Accordingly, a better understanding of the molecular underpinnings of cardiac myocyte hypertrophy is required in order to fully appreciate the causes and functional consequences of the changes in the size of the healthy and diseased heart. Hypertrophy is driven by increases in cardiac myocyte protein, which must be balanced by cellular ability to maintain protein quality in order to avoid maladaptive accumulation of toxic misfolded proteins. Recent studies have shown that the endoplasmic reticulum (ER), which, in cardiac myocytes, comprises the sarco/endoplasmic reticulum (SR/ER), is the site of most protein synthesis. Thus, the protein quality control machinery located at the SR/ER is likely to be an important determinant of whether the heart responds adaptively to hypertrophic growth stimuli. The SR/ER-transmembrane protein, ATF6, serves a critical protein quality control function as a first responder to the accumulation of potentially toxic, misfolded proteins. Misfolded proteins transform ATF6 into a transcription factor that regulates a gene program that is partly responsible for enhancing protein quality control. Two ATF6-inducible genes that have been studied in the heart and shown to be adaptive are RCAN1 and Derl3, which encode proteins that decrease protein-folding demand, and enhance degradation of misfolded proteins, respectively. Thus, the ATF6-regulated SR/ER protein quality control system is important for maintaining protein quality during growth, making ATF6, and other components of the system, potentially attractive targets for the therapeutic management pathological cardiac hypertrophy. This article is part of a Special Issue entitled "Protein Quality Control, the Ubiquitin Proteasome System, and Autophagy".
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Affiliation(s)
- Christopher C Glembotski
- San Diego State University Heart Institute, Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
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Sieck GC, Granger JP, Miller V, Reckelhoff JF, Wang T, Carey H. Physiology's Impact: Discovering Life. Physiology (Bethesda) 2013; 28:4-6. [DOI: 10.1152/physiol.00050.2012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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34
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Sieck G. Design principles for life. Physiology (Bethesda) 2012; 27:330. [PMID: 23223626 DOI: 10.1152/physiol.00046.2012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Highlights from the Literature. Physiology (Bethesda) 2012. [DOI: 10.1152/physiol.00047.2012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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