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Guttipatti P, Saadallah N, Ji R, Avula UMR, Goulbourne CN, Wan EY. Quantitative 3D electron microscopy characterization of mitochondrial structure, mitophagy, and organelle interactions in murine atrial fibrillation. J Struct Biol 2024; 216:108110. [PMID: 39009246 DOI: 10.1016/j.jsb.2024.108110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/05/2024] [Accepted: 07/11/2024] [Indexed: 07/17/2024]
Abstract
Atrial fibrillation (AF) is the most common clinical arrhythmia, however there is limited understanding of its pathophysiology including the cellular and ultrastructural changes rendered by the irregular rhythm, which limits pharmacological therapy development. Prior work has demonstrated the importance of reactive oxygen species (ROS) and mitochondrial dysfunction in the development of AF. Mitochondrial structure, interactions with other organelles such as sarcoplasmic reticulum (SR) and T-tubules (TT), and degradation of dysfunctional mitochondria via mitophagy are important processes to understand ultrastructural changes due to AF. However, most analysis of mitochondrial structure and interactome in AF has been limited to two-dimensional (2D) modalities such as transmission electron microscopy (EM), which does not fully visualize the morphological evolution of the mitochondria during mitophagy. Herein, we utilize focused ion beam-scanning electron microscopy (FIB-SEM) and perform reconstruction of three-dimensional (3D) EM from murine left atrial samples and measure the interactions of mitochondria with SR and TT. We developed a novel 3D quantitative analysis of FIB-SEM in a murine model of AF to quantify mitophagy stage, mitophagosome size in cardiomyocytes, and mitochondrial structural remodeling when compared with control mice. We show that in our murine model of spontaneous and continuous AF due to persistent late sodium current, left atrial cardiomyocytes have heterogenous mitochondria, with a significant number which are enlarged with increased elongation and structural complexity. Mitophagosomes in AF cardiomyocytes are located at Z-lines where they neighbor large, elongated mitochondria. Mitochondria in AF cardiomyocytes show increased organelle interaction, with 5X greater contact area with SR and are 4X as likely to interact with TT when compared to control. We show that mitophagy in AF cardiomyocytes involves 2.5X larger mitophagosomes that carry increased organelle contents. In conclusion, when oxidative stress overcomes compensatory mechanisms, mitophagy in AF faces a challenge of degrading bulky complex mitochondria, which may result in increased SR and TT contacts, perhaps allowing for mitochondrial Ca2+ maintenance and antioxidant production.
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Affiliation(s)
- Pavithran Guttipatti
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.
| | - Najla Saadallah
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.
| | - Ruiping Ji
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.
| | - Uma Mahesh R Avula
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States; Department of Medicine, University of Mississippi, Jackson, MS, United States.
| | - Christopher N Goulbourne
- Center for Dementia Research, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States.
| | - Elaine Y Wan
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States.
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Li Q, Lin J, Luo S, Schmitz‐Abe K, Agrawal R, Meng M, Moghadaszadeh B, Beggs AH, Liu X, Perrella MA, Agrawal PB. Integrated multi-omics approach reveals the role of striated muscle preferentially expressed protein kinase in skeletal muscle including its relationship with myospryn complex. J Cachexia Sarcopenia Muscle 2024; 15:1003-1015. [PMID: 38725372 PMCID: PMC11154751 DOI: 10.1002/jcsm.13470] [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: 05/08/2023] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 05/21/2024] Open
Abstract
BACKGROUND Autosomal-recessive mutations in SPEG (striated muscle preferentially expressed protein kinase) have been linked to centronuclear myopathy with or without dilated cardiomyopathy (CNM5). Loss of SPEG is associated with defective triad formation, abnormal excitation-contraction coupling, calcium mishandling and disruption of the focal adhesion complex in skeletal muscles. To elucidate the underlying molecular pathways, we have utilized multi-omics tools and analysis to obtain a comprehensive view of the complex biological processes and molecular functions. METHODS Skeletal muscles from 2-month-old SPEG-deficient (Speg-CKO) and wild-type (WT) mice were used for RNA sequencing (n = 4 per genotype) to profile transcriptomics and mass spectrometry (n = 4 for WT; n = 3 for Speg-CKO mice) to profile proteomics and phosphoproteomics. In addition, interactomics was performed using the SPEG antibody on pooled muscle lysates (quadriceps, gastrocnemius and triceps) from WT and Speg-CKO mice. Based on the multi-omics results, we performed quantitative real-time PCR, co-immunoprecipitation and immunoblot to verify the findings. RESULTS We identified that SPEG interacts with myospryn complex proteins CMYA5, FSD2 and RyR1, which are critical for triad formation, and that SPEG deficiency results in myospryn complex abnormalities (protein levels decreased to 22 ± 3% for CMYA5 [P < 0.05] and 18 ± 3% for FSD2 [P < 0.01]). Furthermore, SPEG phosphorylates RyR1 at S2902 (phosphorylation level decreased to 55 ± 15% at S2902 in Speg-CKO mice; P < 0.05), and its loss affects JPH2 phosphorylation at multiple sites (increased phosphorylation at T161 [1.90 ± 0.24-fold], S162 [1.61 ± 0.37-fold] and S165 [1.66 ± 0.13-fold]; decreased phosphorylation at S228 and S231 [39 ± 6%], S234 [50 ± 12%], S593 [48 ± 3%] and S613 [66 ± 10%]; P < 0.05 for S162 and P < 0.01 for other sites). On analysing the transcriptome, the most dysregulated pathways affected by SPEG deficiency included extracellular matrix-receptor interaction (P < 1e-15) and peroxisome proliferator-activated receptor signalling (P < 9e-14). CONCLUSIONS We have elucidated the critical role of SPEG in the triad as it works closely with myospryn complex proteins (CMYA5, FSD2 and RyR1), it regulates phosphorylation levels of various residues in JPH2 and S2902 in RyR1, and its deficiency is associated with dysregulation of several pathways. The study identifies unique SPEG-interacting proteins and their phosphorylation functions and emphasizes the importance of using a multi-omics approach to comprehensively evaluate the molecular function of proteins involved in various genetic disorders.
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Affiliation(s)
- Qifei Li
- Division of Neonatology, Department of PediatricsUniversity of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health SystemMiamiFLUSA
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Jasmine Lin
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Shiyu Luo
- Division of Neonatology, Department of PediatricsUniversity of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health SystemMiamiFLUSA
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Klaus Schmitz‐Abe
- Division of Neonatology, Department of PediatricsUniversity of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health SystemMiamiFLUSA
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Rohan Agrawal
- Division of Neonatology, Department of PediatricsUniversity of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health SystemMiamiFLUSA
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Melissa Meng
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Behzad Moghadaszadeh
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Alan H. Beggs
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Xiaoli Liu
- Division of Pulmonary and Critical Care MedicineBrigham and Women's Hospital, Harvard Medical SchoolBostonMAUSA
- Department of Pediatric Newborn MedicineBrigham and Women's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Mark A. Perrella
- Division of Pulmonary and Critical Care MedicineBrigham and Women's Hospital, Harvard Medical SchoolBostonMAUSA
- Department of Pediatric Newborn MedicineBrigham and Women's Hospital, Harvard Medical SchoolBostonMAUSA
| | - Pankaj B. Agrawal
- Division of Neonatology, Department of PediatricsUniversity of Miami Miller School of Medicine and Holtz Children's Hospital, Jackson Health SystemMiamiFLUSA
- Division of Genetics and GenomicsBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
- The Manton Center for Orphan Disease ResearchBoston Children's Hospital, Harvard Medical SchoolBostonMAUSA
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Xu C, Zhang G, Wang X, Huang X, Zhang J, Han S, Wang J, Hall DD, Xu R, He F, Chang X, Wang F, Xie W, Wu Z, Song LS, Han P. Ptpn23 Controls Cardiac T-Tubule Patterning by Promoting the Assembly of Dystrophin-Glycoprotein Complex. Circulation 2024; 149:1375-1390. [PMID: 38214189 PMCID: PMC11039371 DOI: 10.1161/circulationaha.123.065767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 12/14/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Cardiac transverse tubules (T-tubules) are anchored to sarcomeric Z-discs by costameres to establish a regular spaced pattern. One of the major components of costameres is the dystrophin-glycoprotein complex (DGC). Nevertheless, how the assembly of the DGC coordinates with the formation and maintenance of T-tubules under physiological and pathological conditions remains unclear. METHODS Given the known role of Ptpn23 (protein tyrosine phosphatase, nonreceptor type 23) in regulating membrane deformation, its expression in patients with dilated cardiomyopathy was determined. Taking advantage of Cre/Loxp, CRISPR/Cas9, and adeno-associated virus 9 (AAV9)-mediated in vivo gene editing, we generated cardiomyocyte-specific Ptpn23 and Actn2 (α-actinin-2, a major component of Z-discs) knockout mice. We also perturbed the DGC by using dystrophin global knockout mice (DmdE4*). MM 4-64 and Di-8-ANEPPS staining, Cav3 immunofluorescence, and transmission electron microscopy were performed to determine T-tubule structure in isolated cells and intact hearts. In addition, the assembly of the DGC with Ptpn23 and dystrophin loss of function was determined by glycerol-gradient fractionation and SDS-PAGE analysis. RESULTS The expression level of Ptpn23 was reduced in failing hearts from dilated cardiomyopathy patients and mice. Genetic deletion of Ptpn23 resulted in disorganized T-tubules with enlarged diameters and progressive dilated cardiomyopathy without affecting sarcomere organization. AAV9-mediated mosaic somatic mutagenesis further indicated a cell-autonomous role of Ptpn23 in regulating T-tubule formation. Genetic and biochemical analyses showed that Ptpn23 was essential for the integrity of costameres, which anchor the T-tubule membrane to Z-discs, through interactions with α-actinin and dystrophin. Deletion of α-actinin altered the subcellular localization of Ptpn23 and DGCs. In addition, genetic inactivation of dystrophin caused similar T-tubule defects to Ptpn23 loss-of-function without affecting Ptpn23 localization at Z-discs. Last, inducible Ptpn23 knockout at 1 month of age showed Ptpn23 is also required for the maintenance of T-tubules in adult cardiomyocytes. CONCLUSIONS Ptpn23 is essential for cardiac T-tubule formation and maintenance along Z-discs. During postnatal heart development, Ptpn23 interacts with sarcomeric α-actinin and coordinates the assembly of the DGC at costameres to sculpt T-tubule spatial patterning and morphology.
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Affiliation(s)
- Chen Xu
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Ge Zhang
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Xinjian Wang
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Xiaozhi Huang
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Jiayin Zhang
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Shuxian Han
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Jinxi Wang
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Duane D. Hall
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Ruoqing Xu
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Feng He
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
| | - Xing Chang
- Research Center for Industries of the Future, Westlake University, Hangzhou, China
| | - Fudi Wang
- The Fourth Affiliated Hospital, School of Public Health, State Key Laboratory of Experimental Hematology, Zhejiang University School of Medicine, Hangzhou, China
| | - Wenjun Xie
- Department of Cardiology, First Affiliated Hospital of Xi'an Jiaotong University, Xi’an, Shaanxi 710061, China
| | - Zhichao Wu
- Department of Thoracic surgery, People’s hospital of Xinjiang Uyghur autonomous Region, Urumqi, Xinjiang, 830000
- Department of Cardiovascular Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510120
| | - Long-Sheng Song
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Peidong Han
- Center for Genetic Medicine, the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Genetics, Zhejiang University International School of Medicine, Hangzhou, Zhejiang, China
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, Zhejiang, China
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Hall DD, Takeshima H, Song LS. Structure, Function, and Regulation of the Junctophilin Family. Annu Rev Physiol 2024; 86:123-147. [PMID: 37931168 PMCID: PMC10922073 DOI: 10.1146/annurev-physiol-042022-014926] [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] [Indexed: 11/08/2023]
Abstract
In both excitable and nonexcitable cells, diverse physiological processes are linked to different calcium microdomains within nanoscale junctions that form between the plasma membrane and endo-sarcoplasmic reticula. It is now appreciated that the junctophilin protein family is responsible for establishing, maintaining, and modulating the structure and function of these junctions. We review foundational findings from more than two decades of research that have uncovered how junctophilin-organized ultrastructural domains regulate evolutionarily conserved biological processes. We discuss what is known about the junctophilin family of proteins. Our goal is to summarize the current knowledge of junctophilin domain structure, function, and regulation and to highlight emerging avenues of research that help our understanding of the transcriptional, translational, and post-translational regulation of this gene family and its roles in health and during disease.
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Affiliation(s)
- Duane D Hall
- Department of Internal Medicine, Division of Cardiovascular Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; ,
| | - Hiroshi Takeshima
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Long-Sheng Song
- Department of Internal Medicine, Division of Cardiovascular Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; ,
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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Zhang K, Wang S, Li X, Cui H, Lai Y. Mechanism of Ion Channel Impairment in the Occurrence of Arrhythmia in Patients with Hypertrophic Cardiomyopathy. Cardiol Rev 2023:00045415-990000000-00161. [PMID: 37812010 DOI: 10.1097/crd.0000000000000612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Sudden cardiac death is the most unpredictable and devastating consequence of hypertrophic cardiomyopathy, most often caused by persistent ventricular tachycardia or ventricular fibrillation. Although myocardial hypertrophy, fibrosis, and microvascular disorders are the main mechanisms of persistent reentrant ventricular arrhythmias in patients with advanced hypertrophic cardiomyopathy, the cardiomyocyte mechanism based on ion channel abnormalities may play an important role in the early stages of the disease.
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Affiliation(s)
- Ke Zhang
- From the Department of Cardiovascular Surgery
- The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Shengwei Wang
- From the Department of Cardiovascular Surgery
- The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Xiaoyan Li
- The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Hao Cui
- From the Department of Cardiovascular Surgery
- The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
| | - Yongqiang Lai
- From the Department of Cardiovascular Surgery
- The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China
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6
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Lee CS, Jung SY, Yee RSZ, Agha NH, Hong J, Chang T, Babcock LW, Fleischman JD, Clayton B, Hanna AD, Ward CS, Lanza D, Hurley AE, Zhang P, Wehrens XHT, Lagor WR, Rodney GG, Hamilton SL. Speg interactions that regulate the stability of excitation-contraction coupling protein complexes in triads and dyads. Commun Biol 2023; 6:942. [PMID: 37709832 PMCID: PMC10502019 DOI: 10.1038/s42003-023-05330-y] [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: 04/03/2023] [Accepted: 09/07/2023] [Indexed: 09/16/2023] Open
Abstract
Here we show that striated muscle preferentially expressed protein kinase α (Spegα) maintains cardiac function in hearts with Spegβ deficiency. Speg is required for stability of excitation-contraction coupling (ECC) complexes and interacts with esterase D (Esd), Cardiomyopathy-Associated Protein 5 (Cmya5), and Fibronectin Type III and SPRY Domain Containing 2 (Fsd2) in cardiac and skeletal muscle. Mice with a sequence encoding a V5/HA tag inserted into the first exon of the Speg gene (HA-Speg mice) display a >90% decrease in Spegβ but Spegα is expressed at ~50% of normal levels. Mice deficient in both Spegα and Speg β (Speg KO mice) develop a severe dilated cardiomyopathy and muscle weakness and atrophy, but HA-Speg mice display mild muscle weakness with no cardiac involvement. Spegα in HA-Speg mice suppresses Ca2+ leak, proteolytic cleavage of Jph2, and disruption of transverse tubules. Despite it's low levels, HA-Spegβ immunoprecipitation identified Esd, Cmya5 and Fsd2 as Spegβ binding partners that localize to triads and dyads to stabilize ECC complexes. This study suggests that Spegα and Spegβ display functional redundancy, identifies Esd, Cmya5 and Fsd2 as components of both cardiac dyads and skeletal muscle triads and lays the groundwork for the identification of new therapeutic targets for centronuclear myopathy.
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Affiliation(s)
- Chang Seok Lee
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Sung Yun Jung
- Department of Biochemistry, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Rachel Sue Zhen Yee
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Nadia H Agha
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Jin Hong
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Ting Chang
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Lyle W Babcock
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Jorie D Fleischman
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Benjamin Clayton
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Amy D Hanna
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Christopher S Ward
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Denise Lanza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Ayrea E Hurley
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Pumin Zhang
- The First Affiliated Hospital, Zhejiang University Medical School, Hangzhou, China
| | - Xander H T Wehrens
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - William R Lagor
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - George G Rodney
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA
| | - Susan L Hamilton
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, 77096, USA.
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7
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Pfeuffer AKM, Küpfer LK, Shankar TS, Drakos SG, Volk T, Seidel T. Ryanodine Receptor Staining Identifies Viable Cardiomyocytes in Human and Rabbit Cardiac Tissue Slices. Int J Mol Sci 2023; 24:13514. [PMID: 37686327 PMCID: PMC10488113 DOI: 10.3390/ijms241713514] [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: 08/06/2023] [Revised: 08/26/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
In terms of preserving multicellularity and myocardial function in vitro, the cultivation of beating myocardial slices is an emerging technique in basic and translational cardiac research. It can be used, for example, for drug screening or to study pathomechanisms. Here, we describe staining for viable cardiomyocytes based on the immunofluorescence of ryanodine receptors (RyRs) in human and rabbit myocardial slices. Biomimetic chambers were used for culture and measurements of contractile force. Fixable fluorophore-conjugated dextran, entering cells with a permeable membrane, was used for death staining. RyRs, nuclei and the extracellular matrix, including the t-system, were additionally stained and analyzed by confocal microscopy and image processing. We found the mutual exclusion of the RyR and dextran signals in cultivated slices. T-System density and nucleus size were reduced in RyR-negative/dextran-positive myocytes. The fraction of RyR-positive myocytes and pixels correlated with the contractile force. In RyR-positive/dextran-positive myocytes, we found irregular RyR clusters and SERCA distribution patterns, confirmed by an altered power spectrum. We conclude that RyR immunofluorescence indicates viable cardiomyocytes in vibratome-cut myocardial slices, facilitating the detection and differential structural analysis of living vs. dead or dying myocytes. We suggest the loss of sarcoplasmic reticulum integrity as an early event during cardiomyocyte death.
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Affiliation(s)
- Ann-Katrin M. Pfeuffer
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University (FAU) Erlangen-Nuremberg, 91054 Erlangen, Germany; (A.-K.M.P.); (L.K.K.); (T.V.)
| | - Linda K. Küpfer
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University (FAU) Erlangen-Nuremberg, 91054 Erlangen, Germany; (A.-K.M.P.); (L.K.K.); (T.V.)
| | - Thirupura S. Shankar
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; (T.S.S.); (S.G.D.)
| | - Stavros G. Drakos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT 84112, USA; (T.S.S.); (S.G.D.)
| | - Tilmann Volk
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University (FAU) Erlangen-Nuremberg, 91054 Erlangen, Germany; (A.-K.M.P.); (L.K.K.); (T.V.)
| | - Thomas Seidel
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander University (FAU) Erlangen-Nuremberg, 91054 Erlangen, Germany; (A.-K.M.P.); (L.K.K.); (T.V.)
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8
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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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9
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Manfra O, Louey S, Jonker SS, Perdreau-Dahl H, Frisk M, Giraud GD, Thornburg KL, Louch WE. Augmenting workload drives T-tubule assembly in developing cardiomyocytes. J Physiol 2023:10.1113/JP284538. [PMID: 37128962 PMCID: PMC10854476 DOI: 10.1113/jp284538] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023] Open
Abstract
Contraction of cardiomyocytes is initiated at subcellular elements called dyads, where L-type Ca2+ channels in t-tubules are located within close proximity to ryanodine receptors in the sarcoplasmic reticulum. While evidence from small rodents indicates that dyads are assembled gradually in the developing heart, it is unclear how this process occurs in large mammals. We presently examined dyadic formation in fetal and newborn sheep (Ovis aries), and the regulation of this process by fetal cardiac workload. By employing advanced imaging methods, we demonstrated that t-tubule growth and dyadic assembly proceed gradually during fetal sheep development, from 93 days of gestational age until birth (147 days). This process parallels progressive increases in fetal systolic blood pressure, and includes step-wise colocalization of L-type Ca2+ channels and the Na+ /Ca2+ exchanger with ryanodine receptors. These proteins are upregulated together with the dyadic anchor junctophilin-2 during development, alongside changes in the expression of amphiphysin-2 (BIN1) and its partner proteins myotubularin and dynamin-2. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth. Conversely, reducing fetal systolic load with infusion of enalaprilat, an angiotensin converting enzyme inhibitor, blunted t-tubule formation. Interestingly, altered t-tubule densities did not relate to changes in dyadic junctions, or marked changes in the expression of dyadic regulatory proteins, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum. In conclusion, augmenting blood pressure and workload during normal fetal development critically promotes t-tubule growth, while additional signals contribute to dyadic assembly. KEY POINTS: T-tubule growth and dyadic assembly proceed gradually in cardiomyocytes during fetal sheep development, from 93 days of gestational age until the post-natal stage. Increasing fetal systolic load by infusing plasma or occluding the post-ductal aorta accelerated t-tubule growth and hypertrophy. In contrast, reducing fetal systolic load by enalaprilat infusion slowed t-tubule development and decreased cardiomyocyte size. Load-dependent modulation of t-tubule maturation was linked to altered expression patterns of the t-tubule regulatory proteins junctophilin-2 and amphiphysin-2 (BIN1) and its protein partners. Altered t-tubule densities did not influence dyadic formation, indicating that distinct signals are responsible for maturation of the sarcoplasmic reticulum.
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Affiliation(s)
- Ornella Manfra
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Samantha Louey
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Sonnet S Jonker
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - Harmonie Perdreau-Dahl
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - George D Giraud
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
- VA Portland Health Care System Portland, OR, USA
| | - Kent L Thornburg
- Center for Developmental Health, Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, OR, USA
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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10
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Li Q, Lin J, Luo S, Schmitz-Abe K, Agrawal R, Meng M, Moghadaszadeh B, Beggs AH, Liu X, Perrella MA, Agrawal PB. Integrated multi-omics approach reveals the role of SPEG in skeletal muscle biology including its relationship with myospryn complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538136. [PMID: 37162921 PMCID: PMC10168260 DOI: 10.1101/2023.04.24.538136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Autosomal-recessive mutations in SPEG (striated muscle preferentially expressed protein kinase) have been linked to centronuclear myopathy. Loss of SPEG is associated with defective triad formation, abnormal excitation-contraction coupling, and calcium mishandling in skeletal muscles. To elucidate the underlying molecular pathways, we have utilized multi-omics tools and analysis to obtain a comprehensive view of the complex biological processes. We identified that SPEG interacts with myospryn complex proteins (CMYA5, FSD2, RyR1), and SPEG deficiency results in myospryn complex abnormalities. In addition, transcriptional and protein profiles of SPEG-deficient muscle revealed defective mitochondrial function including aberrant accumulation of enlarged mitochondria on electron microscopy. Furthermore, SPEG regulates RyR1 phosphorylation at S2902, and its loss affects JPH2 phosphorylation at multiple sites. On analyzing the transcriptome, the most dysregulated pathways affected by SPEG deficiency included extracellular matrix-receptor interaction and peroxisome proliferator-activated receptors signaling, which may be due to defective triad and mitochondrial abnormalities. In summary, we have elucidated the critical role of SPEG in triad as it works closely with myospryn complex, phosphorylates JPH2 and RyR1, and demonstrated that its deficiency is associated with mitochondrial abnormalities. This study emphasizes the importance of using multi-omics techniques to comprehensively analyze the molecular anomalies of rare diseases. Synopsis We have previously linked mutations in SPEG (striated preferentially expressed protein) with a recessive form of centronuclear myopathy and/or dilated cardiomyopathy and have characterized a striated muscle-specific SPEG-deficient mouse model that recapitulates human disease with disruption of the triad structure and calcium homeostasis in skeletal muscles. In this study, we applied multi-omics approaches (interactomic, proteomic, phosphoproteomic, and transcriptomic analyses) in the skeletal muscles of SPEG-deficient mice to assess the underlying pathways associated with the pathological and molecular abnormalities. SPEG interacts with myospryn complex proteins (CMYA5, FSD2, RyR1), and its deficiency results in myospryn complex abnormalities.SPEG regulates RyR1 phosphorylation at S2902, and its loss affects JPH2 phosphorylation at multiple sites.SPEGα and SPEGβ have different interacting partners suggestive of differential function.Transcriptome analysis indicates dysregulated pathways of ECM-receptor interaction and peroxisome proliferator-activated receptor signaling.Mitochondrial defects on the transcriptome, proteome, and electron microscopy, may be a consequence of defective calcium signaling.
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11
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Kermani F, Mosqueira M, Peters K, Lemma ED, Rapti K, Grimm D, Bastmeyer M, Laugsch M, Hecker M, Ullrich ND. Membrane remodelling triggers maturation of excitation-contraction coupling in 3D-shaped human-induced pluripotent stem cell-derived cardiomyocytes. Basic Res Cardiol 2023; 118:13. [PMID: 36988697 PMCID: PMC10060306 DOI: 10.1007/s00395-023-00984-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/14/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023]
Abstract
The prospective use of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) for cardiac regenerative medicine strongly depends on the electro-mechanical properties of these cells, especially regarding the Ca2+-dependent excitation-contraction (EC) coupling mechanism. Currently, the immature structural and functional features of hiPSC-CM limit the progression towards clinical applications. Here, we show that a specific microarchitecture is essential for functional maturation of hiPSC-CM. Structural remodelling towards a cuboid cell shape and induction of BIN1, a facilitator of membrane invaginations, lead to transverse (t)-tubule-like structures. This transformation brings two Ca2+ channels critical for EC coupling in close proximity, the L-type Ca2+ channel at the sarcolemma and the ryanodine receptor at the sarcoplasmic reticulum. Consequently, the Ca2+-dependent functional interaction of these channels becomes more efficient, leading to improved spatio-temporal synchronisation of Ca2+ transients and higher EC coupling gain. Thus, functional maturation of hiPSC-cardiomyocytes by optimised cell microarchitecture needs to be considered for future cardiac regenerative approaches.
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Affiliation(s)
- Fatemeh Kermani
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Matias Mosqueira
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Kyra Peters
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
| | - Enrico D Lemma
- Zoological Institute, Cell and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Kleopatra Rapti
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Heidelberg University, Heidelberg, Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Section Viral Vector Technologies, Heidelberg University, Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- German Center for Infection Research (DZIF), Partner Site Heidelberg, Heidelberg, Germany
| | - Martin Bastmeyer
- Zoological Institute, Cell and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
- Institute of Biological and Chemical Systems-Biological information processing (IBCS-BIP), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
- Research Bridge (Synthetic Biology), Heidelberg-Karlsruhe Research Partnership (HEiKA), Heidelberg University and Karlsruhe Institute of Technology, Heidelberg, Germany
| | - Magdalena Laugsch
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Markus Hecker
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Nina D Ullrich
- Department of Cardiovascular Physiology, Heidelberg University, Heidelberg, Germany.
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Heidelberg, Germany.
- Research Bridge (Synthetic Biology), Heidelberg-Karlsruhe Research Partnership (HEiKA), Heidelberg University and Karlsruhe Institute of Technology, Heidelberg, Germany.
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12
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Dixon RE, Trimmer JS. Endoplasmic Reticulum-Plasma Membrane Junctions as Sites of Depolarization-Induced Ca 2+ Signaling in Excitable Cells. Annu Rev Physiol 2023; 85:217-243. [PMID: 36202100 PMCID: PMC9918718 DOI: 10.1146/annurev-physiol-032122-104610] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane contact sites between endoplasmic reticulum (ER) and plasma membrane (PM), or ER-PM junctions, are found in all eukaryotic cells. In excitable cells they play unique roles in organizing diverse forms of Ca2+ signaling as triggered by membrane depolarization. ER-PM junctions underlie crucial physiological processes such as excitation-contraction coupling, smooth muscle contraction and relaxation, and various forms of activity-dependent signaling and plasticity in neurons. In many cases the structure and molecular composition of ER-PM junctions in excitable cells comprise important regulatory feedback loops linking depolarization-induced Ca2+ signaling at these sites to the regulation of membrane potential. Here, we describe recent findings on physiological roles and molecular composition of native ER-PM junctions in excitable cells. We focus on recent studies that provide new insights into canonical forms of depolarization-induced Ca2+ signaling occurring at junctional triads and dyads of striated muscle, as well as the diversity of ER-PM junctions in these cells and in smooth muscle and neurons.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, California, USA;
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13
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Liu L, Zhou K, Liu X, Hua Y, Wang H, Li Y. The interplay between cardiac dyads and mitochondria regulated the calcium handling in cardiomyocytes. Front Physiol 2022; 13:1013817. [PMID: 36531185 PMCID: PMC9755166 DOI: 10.3389/fphys.2022.1013817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 11/24/2022] [Indexed: 11/15/2023] Open
Abstract
Calcium mishandling and mitochondrial dysfunction have been increasingly recognized as significant factors involved in the progression procedure of cardiomyopathy. Ca2+ mishandling could cause calcium-triggered arrhythmias, which could enhance force development and ATP consumption. Mitochondrial disorganization and dysfunction in cardiomyopathy could disturb the balance of energy catabolic and anabolic procedure. Close spatial localization and arrangement of structural among T-tubule, sarcoplasmic reticulum, mitochondria are important for Ca2+ handling. So that, we illustrate the regulating network between calcium handling and mitochondrial homeostasis, as well as its intracellular mechanisms in this review, which would be worthy to develop novel therapeutic strategy and restore the function of injured cardiomyocytes.
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Affiliation(s)
| | | | | | | | - Hua Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yifei Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
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14
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Abstract
Cardiac dyads are the site of communication between the sarcoplasmic reticulum (SR) and infoldings of the sarcolemma called transverse-tubules (TT). During heart excitation–contraction coupling, Ca2+-influx through L-type Ca2+ channels in the TT is amplified by release of Ca2+-from the SR via type 2 ryanodine receptors, activating the contractile apparatus. Key proteins involved in cardiac dyad function are bridging integrator 1 (BIN1), junctophilin 2 and caveolin 3. The work presented here aims to reconstruct the evolutionary history of the cardiac dyad, by surveying the scientific literature for ultrastructural evidence of these junctions across all animal taxa; phylogenetically reconstructing the evolutionary history of BIN1; and by comparing peptide motifs involved in TT formation by this protein across metazoans. Key findings are that cardiac dyads have been identified in mammals, arthropods and molluscs, but not in other animals. Vertebrate BIN1 does not group with members of this protein family from other taxa, suggesting that invertebrate BINs are paralogues rather orthologues of this gene. Comparisons of BIN1 peptide sequences of mammals with those of other vertebrates reveals novel features that might contribute to TT and dyad formation. The analyses presented here suggest that the cardiac dyad evolved independently several times during metazoan evolution: an unexpected observation given the diversity of heart structure and function between different animal taxa. This article is part of the theme issue ‘The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease’.
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Affiliation(s)
- John James Mackrill
- Department of Physiology, School of Medicine, University College Cork, Western Gateway Building, Western Road, Cork T12 XF62, Republic of Ireland
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15
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Shexiang Baoxin Pills Could Alleviate Isoproterenol-Induced Heart Failure Probably through its Inhibition of CaV1.2 Calcium Channel Currents. Biochem Res Int 2022; 2022:5498023. [DOI: 10.1155/2022/5498023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 10/08/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022] Open
Abstract
Heart failure (HF) affects millions of patients in the world. Shexiang Baoxin Pills (SXB) are extensively applied to treat coronary artery diseases and HF in Chinese hospitals. However, there are still no explanations for why SXB protects against HF. To assess the protective role, we created the HF model in rats by isoproterenol (ISO) subcutaneous injection, 85 milligrams per kilogram body weight for seven days. Four groups were implemented: CON (control), ISO (HF disease group), CAP (captopril, positive drug treatment), and SXB groups. Echocardiography was used to evaluate rats’ HF in vivo. The human CaV1.2 (hCaV1.2) channel currents were detected in tsA-201 cells by patch clamp technique. Five different concentrations of SXB (5, 10, 30, 50, and 100 mg/L) were chosen in this study. The results showed that SXB increased cardiac systolic function and inhibited rats’ cardiac hypertrophy and myocardial fibrosis induced by ISO. Subsequently, it was found that SXB was inhibited by the peak amplitudes of hCaV1.2 channel current (
). The SXB half inhibitory dosage was 9.09 mg/L. The steady-state activation curve was 22.8 mV depolarization shifted; while the inactivation curve and the recovery from inactivation were not affected significantly. In conclusion, these results indicated that SXB inhibited ISO-induced HF in rats and inhibited the hCaV1.2 channel current. The present study paved the way for SXB to protect itself from HF.
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16
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Yu L, Hall DD, Zhao W, Song LS. NMR resonance assignments of the DNA binding domain of mouse Junctophilin-2. BIOMOLECULAR NMR ASSIGNMENTS 2022; 16:273-279. [PMID: 35665900 PMCID: PMC10394741 DOI: 10.1007/s12104-022-10091-6] [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: 04/22/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Junctophilin-2 (JP2) is a critical structural protein in the heart by stabilizing junctional membrane complexes between the plasma membrane and sarcoplasmic reticula responsible for precise Ca2+ regulation. Such complexes are essential for efficient cardiomyocyte contraction and adaptation to altered cardiac workload conditions. Mutations in the JPH2 gene that encodes JP2 are associated with inherited cardiomyopathies and arrhythmias, and disruption of JP2 function is lethal. Interestingly, cardiac stress promotes the proteolytic cleavage of JP2 that triggers the translocation of its N-terminal fragment into the nucleus to repress maladaptive gene transcription. We previously found that the central region of JP2 is responsible for mediating direct DNA binding interactions. Recent structural studies indicate that this region serves as a structural role in the cytosolic form of JP2 by folding into a single continuous α-helix. However, the structural basis of how this DNA-binding domain interacts with DNA is not known. Here, we report the backbone and sidechain assignments of the DNA-binding domain (residues 331-413) of mouse JP2. These assignments reveal that the JP2 DNA binding domain is an intrinsically disordered protein and contains two α-helices located in the C-terminal portion of the protein. Moreover, this protein binds to DNA in a similar manner to that shown previously by electrophoretic mobility shift assays. Therefore, these assignments provide a framework for further structural studies into the interaction of this JP2 domain with DNA for the elucidation of transcriptional regulation of stress-responsive genes as well as its role in the stabilization of junctional membrane complexes.
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Affiliation(s)
- Liping Yu
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, B291, CBRB, 285 Newton Road, Iowa City, IA, 52242, USA.
- CCOM NMR Core Facility, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
| | - Duane D Hall
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA
| | - Weiyang Zhao
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA
| | - Long-Sheng Song
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, B291, CBRB, 285 Newton Road, Iowa City, IA, 52242, USA.
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, 285 Newton Road, Iowa City, IA, 52242, USA.
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
- Iowa City Veterans Affairs Medical Center, Iowa City, IA, 52242, USA.
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17
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Guarina L, Moghbel AN, Pourhosseinzadeh MS, Cudmore RH, Sato D, Clancy CE, Santana LF. Biological noise is a key determinant of the reproducibility and adaptability of cardiac pacemaking and EC coupling. J Gen Physiol 2022; 154:213185. [PMID: 35482009 PMCID: PMC9059386 DOI: 10.1085/jgp.202012613] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/16/2022] [Accepted: 04/07/2022] [Indexed: 12/23/2022] Open
Abstract
Each heartbeat begins with the generation of an action potential in pacemaking cells in the sinoatrial node. This signal triggers contraction of cardiac muscle through a process termed excitation-contraction (EC) coupling. EC coupling is initiated in dyadic structures of cardiac myocytes, where ryanodine receptors in the junctional sarcoplasmic reticulum come into close apposition with clusters of CaV1.2 channels in invaginations of the sarcolemma. Cooperative activation of CaV1.2 channels within these clusters causes a local increase in intracellular Ca2+ that activates the juxtaposed ryanodine receptors. A salient feature of healthy cardiac function is the reliable and precise beat-to-beat pacemaking and amplitude of Ca2+ transients during EC coupling. In this review, we discuss recent discoveries suggesting that the exquisite reproducibility of this system emerges, paradoxically, from high variability at subcellular, cellular, and network levels. This variability is attributable to stochastic fluctuations in ion channel trafficking, clustering, and gating, as well as dyadic structure, which increase intracellular Ca2+ variance during EC coupling. Although the effects of these large, local fluctuations in function and organization are sometimes negligible at the macroscopic level owing to spatial-temporal summation within and across cells in the tissue, recent work suggests that the "noisiness" of these intracellular Ca2+ events may either enhance or counterintuitively reduce variability in a context-dependent manner. Indeed, these noisy events may represent distinct regulatory features in the tuning of cardiac contractility. Collectively, these observations support the importance of incorporating experimentally determined values of Ca2+ variance in all EC coupling models. The high reproducibility of cardiac contraction is a paradoxical outcome of high Ca2+ signaling variability at subcellular, cellular, and network levels caused by stochastic fluctuations in multiple processes in time and space. This underlying stochasticity, which counterintuitively manifests as reliable, consistent Ca2+ transients during EC coupling, also allows for rapid changes in cardiac rhythmicity and contractility in health and disease.
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Affiliation(s)
- Laura Guarina
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Ariana Neelufar Moghbel
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | | | - Robert H Cudmore
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA
| | - Colleen E Clancy
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Luis Fernando Santana
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
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18
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Dong T, Zhao Y, Jin HF, Shen L, Lin Y, Si LL, Chen L, Liu JC. SNTA1-deficient human cardiomyocytes demonstrate hypertrophic phenotype and calcium handling disorder. Stem Cell Res Ther 2022; 13:288. [PMID: 35773684 PMCID: PMC9248201 DOI: 10.1186/s13287-022-02955-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/07/2022] [Indexed: 11/13/2022] Open
Abstract
Background α-1-syntrophin (SNTA1), a protein encoded by SNTA1, is highly expressed in human cardiomyocytes. Mutations in SNTA1 are associated with arrhythmia and cardiomyopathy. Previous research on SNTA1 has been based on non-human cardiomyocytes. This study was designed to identify the phenotype of SNTA1-deficiency using human cardiomyocytes. Methods SNTA1 was knocked out in the H9 embryonic stem cell line using the CRISPR-Cas9 system. H9SNTA1KO cells were then induced to differentiate into cardiomyocytes using small molecule inhibitors. The phenotypic discrepancies associated with SNTA1-deficient cardiomyocytes were investigated. Results SNTA1 was truncated at the 149th amino acid position of PH1 domain by a stop codon (TGA) using the CRISPR-Cas9 system. SNTA1-deficiency did not affect the pluripotency of H9SNTA1KO, and they retain their in vitro ability to differentiate into cardiomyocytes. However, H9SNTA1KO derived cardiomyocytes exhibited hypertrophic phenotype, lower cardiac contractility, weak calcium transient intensity, and lower level of calcium in the sarcoplasmic reticulum. Early treatment of SNTA1-deficient cardiomyocytes with ranolazine improved the calcium transient intensity and cardiac contractility. Conclusion SNTA1-deficient cardiomyocytes can be used to research the etiology, pathogenesis, and potential therapies for myocardial diseases. The SNTA1-deficient cardiomyocyte model suggests that the maintenance of cardiac calcium homeostasis is a key target in the treatment of myocardial-related diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02955-4.
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Affiliation(s)
- Tao Dong
- Basic Medicine School, Qiqihar Medical University, 333 Bukui Street, Qiqihar, 161006, Heilongjiang, China.
| | - Yan Zhao
- College of Life Science and Agroforestry, Qiqihar University, Qiqihar, 161006, Heilongjiang, China
| | - Hai-Feng Jin
- Basic Medicine School, Qiqihar Medical University, 333 Bukui Street, Qiqihar, 161006, Heilongjiang, China
| | - Lei Shen
- Basic Medicine School, Qiqihar Medical University, 333 Bukui Street, Qiqihar, 161006, Heilongjiang, China
| | - Yan Lin
- Basic Medicine School, Qiqihar Medical University, 333 Bukui Street, Qiqihar, 161006, Heilongjiang, China
| | - Long-Long Si
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Li Chen
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ji-Cheng Liu
- Qiqihar Institute of Medical and Pharmaceutical Sciences, Qiqihar Medical University, 333 Bukui Street, Qiqihar, 161006, Heilongjiang, China.
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19
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Weninger G, Pochechueva T, El Chami D, Luo X, Kohl T, Brandenburg S, Urlaub H, Guan K, Lenz C, Lehnart SE. Calpain cleavage of Junctophilin-2 generates a spectrum of calcium-dependent cleavage products and DNA-rich NT 1-fragment domains in cardiomyocytes. Sci Rep 2022; 12:10387. [PMID: 35725601 PMCID: PMC9209451 DOI: 10.1038/s41598-022-14320-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Calpains are calcium-activated neutral proteases involved in the regulation of key signaling pathways. Junctophilin-2 (JP2) is a Calpain-specific proteolytic target and essential structural protein inside Ca2+ release units required for excitation-contraction coupling in cardiomyocytes. While downregulation of JP2 by Calpain cleavage in heart failure has been reported, the precise molecular identity of the Calpain cleavage sites and the (patho-)physiological roles of the JP2 proteolytic products remain controversial. We systematically analyzed the JP2 cleavage fragments as function of Calpain-1 versus Calpain-2 proteolytic activities, revealing that both Calpain isoforms preferentially cleave mouse JP2 at R565, but subsequently at three additional secondary Calpain cleavage sites. Moreover, we identified the Calpain-specific primary cleavage products for the first time in human iPSC-derived cardiomyocytes. Knockout of RyR2 in hiPSC-cardiomyocytes destabilized JP2 resulting in an increase of the Calpain-specific cleavage fragments. The primary N-terminal cleavage product NT1 accumulated in the nucleus of mouse and human cardiomyocytes in a Ca2+-dependent manner, closely associated with euchromatic chromosomal regions, where NT1 is proposed to function as a cardio-protective transcriptional regulator in heart failure. Taken together, our data suggest that stabilizing NT1 by preventing secondary cleavage events by Calpain and other proteases could be an important therapeutic target for future studies.
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Affiliation(s)
- Gunnar Weninger
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Department of Physiology and Cellular Biophysics, Center for Molecular Cardiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Tatiana Pochechueva
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany
| | - Dana El Chami
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany
| | - Xiaojing Luo
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01307, Dresden, Germany
| | - Tobias Kohl
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany
| | - Sören Brandenburg
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany.,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany.,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany
| | - Henning Urlaub
- Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany.,Proteomanalyse, Department of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
| | - Kaomei Guan
- Institute of Pharmacology and Toxicology, Technische Universität Dresden, 01307, Dresden, Germany
| | - Christof Lenz
- Proteomanalyse, Department of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany.
| | - Stephan E Lehnart
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Robert-Koch-Str. 42a, 37075, Göttingen, Germany. .,Department of Cardiology and Pneumology, University Medical Center Göttingen, 37075, Göttingen, Germany. .,Collaborative Research Center SFB1190 "Compartmental Gates and Contact Sites in Cells", University of Göttingen, 37073, Göttingen, Germany. .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC2067), University of Göttingen, 37073, Göttingen, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site, 37075, Göttingen, Germany.
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20
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Sarcoplasmic Reticulum Ca2+ Dysregulation in the Pathophysiology of Inherited Arrhythmia: An Update. Biochem Pharmacol 2022; 200:115059. [DOI: 10.1016/j.bcp.2022.115059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022]
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21
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Zhou J, Liu H, Lin Y, Zhao J. Membrane Occupation and Recognition Nexus (MORN) motif controls protein localization and function. FEBS Lett 2022; 596:1839-1850. [PMID: 35568981 DOI: 10.1002/1873-3468.14378] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/23/2022] [Accepted: 05/07/2022] [Indexed: 11/06/2022]
Abstract
Membrane Occupation and Recognition Nexus (MORN) motif was first defined in 2000, when it was identified in the junctophilin protein family. Dozens of studies have been published ever since, mainly focusing on the function of a given MORN motif-containing protein in parasites, plants or animal cells. Proteins with MORN motifs are not only expressed in most animal and plant cell types but also significantly differ in their intracellular localization, suggesting that the MORN motifs may fulfil multiple physiological functions. Recent studies have found that MORN motif-containing proteins junctophilin 1/2 and MORN3 play a role in cardiac hypertrophy, skeletal muscle fiber stability and cancer. Hence, MORN motif-containing proteins may be exploited to develop improved treatments for various pathological conditions, such as cardiovascular diseases. Here, we review current research on MORN motif-containing proteins in different organisms and provide both ideas and approaches for follow-up exploration of their functions and applications.
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Affiliation(s)
- Jinrun Zhou
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Qingdao, 266237, P. R. China
| | - Honghong Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Qingdao, 266237, P. R. China
| | - Yushuang Lin
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Qingdao, 266237, P. R. China
| | - Jing Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Qingdao, 266237, P. R. China
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22
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Wright P, Gorelik J. Junctophillin-2: Coupling Hopes for Cardiac Gene Therapy to Gene Transcription. Circ Res 2022; 130:1318-1320. [PMID: 35482830 DOI: 10.1161/circresaha.122.321066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Peter Wright
- School of Life and Health Sciences, University of Roehampton, London, United Kingdom (P.W.)
- National Heart, and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, United Kingdom (P.W., J.G.)
| | - Julia Gorelik
- National Heart, and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, United Kingdom (P.W., J.G.)
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23
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Wang J, Shi Q, Wang Y, Dawson LW, Ciampa G, Zhao W, Zhang G, Chen B, Weiss RM, Grueter CE, Hall DD, Song LS. Gene Therapy With the N-Terminus of Junctophilin-2 Improves Heart Failure in Mice. Circ Res 2022; 130:1306-1317. [PMID: 35317607 PMCID: PMC9050933 DOI: 10.1161/circresaha.121.320680] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Transcriptional remodeling is known to contribute to heart failure (HF). Targeting stress-dependent gene expression mechanisms may represent a clinically relevant gene therapy option. We recently uncovered a salutary mechanism in the heart whereby JP2 (junctophilin-2), an essential component of the excitation-contraction coupling apparatus, is site-specifically cleaved and releases an N-terminal fragment (JP2NT [N-terminal fragment of JP2]) that translocates into the nucleus and functions as a transcriptional repressor of HF-related genes. This study aims to determine whether JP2NT can be leveraged by gene therapy techniques for attenuating HF progression in a preclinical pressure overload model. METHODS We intraventricularly injected adeno-associated virus (AAV) (2/9) vectors expressing eGFP (enhanced green fluorescent protein), JP2NT, or DNA-binding deficient JP2NT (JP2NTΔbNLS/ARR) into neonatal mice and induced cardiac stress by transaortic constriction (TAC) 9 weeks later. We also treated mice with established moderate HF from TAC stress with either AAV-JP2NT or AAV-eGFP. RNA-sequencing analysis was used to reveal changes in hypertrophic and HF-related gene transcription by JP2NT gene therapy after TAC. Echocardiography, confocal imaging, and histology were performed to evaluate heart function and pathological myocardial remodeling following stress. RESULTS Mice preinjected with AAV-JP2NT exhibited ameliorated cardiac remodeling following TAC. The JP2NT DNA-binding domain is required for cardioprotection as its deletion within the AAV-JP2NT vector prevented improvement in TAC-induced cardiac dysfunction. Functional and histological data suggest that JP2NT gene therapy after the onset of cardiac dysfunction is effective at slowing the progression of HF. RNA-sequencing analysis further revealed a broad reversal of hypertrophic and HF-related gene transcription by JP2NT overexpression after TAC. CONCLUSIONS Our prevention- and intervention-based approaches here demonstrated that AAV-mediated delivery of JP2NT into the myocardium can attenuate stress-induced transcriptional remodeling and the development of HF when administered either before or after cardiac stress initiation. Our data indicate that JP2NT gene therapy holds great potential as a novel therapeutic for treating hypertrophy and HF.
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Affiliation(s)
- Jinxi Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Qian Shi
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Yihui Wang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Logan W. Dawson
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
| | - Grace Ciampa
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
| | - Weiyang Zhao
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Guangqin Zhang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Biyi Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Robert M. Weiss
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Chad E. Grueter
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Duane D. Hall
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa, Iowa City, IA 52242
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
- Department of Veterans Affairs, Iowa City Medical Center, IA 52242
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24
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Caporizzo MA, Prosser BL. The microtubule cytoskeleton in cardiac mechanics and heart failure. Nat Rev Cardiol 2022; 19:364-378. [PMID: 35440741 DOI: 10.1038/s41569-022-00692-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/14/2022] [Indexed: 12/13/2022]
Abstract
The microtubule network of cardiac muscle cells has unique architectural and biophysical features to accommodate the demands of the working heart. Advances in live-cell imaging and in deciphering the 'tubulin code' have shone new light on this cytoskeletal network and its role in heart failure. Microtubule-based transport orchestrates the growth and maintenance of the contractile apparatus through spatiotemporal control of translation, while also organizing the specialized membrane systems required for excitation-contraction coupling. To withstand the high mechanical loads of the working heart, microtubules are post-translationally modified and physically reinforced. In response to stress to the myocardium, the microtubule network remodels, typically through densification, post-translational modification and stabilization. Under these conditions, physically reinforced microtubules resist the motion of the cardiomyocyte and increase myocardial stiffness. Accordingly, modified microtubules have emerged as a therapeutic target for reducing stiffness in heart failure. In this Review, we discuss the latest evidence on the contribution of microtubules to cardiac mechanics, the drivers of microtubule network remodelling in cardiac pathologies and the therapeutic potential of targeting cardiac microtubules in acquired heart diseases.
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Affiliation(s)
- Matthew A Caporizzo
- Department of Molecular Physiology and Biophysics, University of Vermont Larner College of Medicine, Burlington, VT, USA.,Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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25
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Rossi D, Pierantozzi E, Amadsun DO, Buonocore S, Rubino EM, Sorrentino V. The Sarcoplasmic Reticulum of Skeletal Muscle Cells: A Labyrinth of Membrane Contact Sites. Biomolecules 2022; 12:488. [PMID: 35454077 PMCID: PMC9026860 DOI: 10.3390/biom12040488] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/14/2022] [Accepted: 03/18/2022] [Indexed: 12/17/2022] Open
Abstract
The sarcoplasmic reticulum of skeletal muscle cells is a highly ordered structure consisting of an intricate network of tubules and cisternae specialized for regulating Ca2+ homeostasis in the context of muscle contraction. The sarcoplasmic reticulum contains several proteins, some of which support Ca2+ storage and release, while others regulate the formation and maintenance of this highly convoluted organelle and mediate the interaction with other components of the muscle fiber. In this review, some of the main issues concerning the biology of the sarcoplasmic reticulum will be described and discussed; particular attention will be addressed to the structure and function of the two domains of the sarcoplasmic reticulum supporting the excitation-contraction coupling and Ca2+-uptake mechanisms.
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Affiliation(s)
- Daniela Rossi
- Department of Molecular and Developmental Medicine, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (E.P.); (D.O.A.); (S.B.); (E.M.R.); (V.S.)
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26
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Yang ZF, Panwar P, McFarlane CR, Tuinte WE, Campiglio M, Van Petegem F. Structures of the junctophilin/voltage-gated calcium channel interface reveal hot spot for cardiomyopathy mutations. Proc Natl Acad Sci U S A 2022; 119:e2120416119. [PMID: 35238659 PMCID: PMC8916002 DOI: 10.1073/pnas.2120416119] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/31/2022] [Indexed: 01/19/2023] Open
Abstract
SignificanceIon channels have evolved the ability to communicate with one another, either through protein-protein interactions, or indirectly via intermediate diffusible messenger molecules. In special cases, the channels are part of different membranes. In muscle tissue, the T-tubule membrane is in proximity to the sarcoplasmic reticulum, allowing communication between L-type calcium channels and ryanodine receptors. This process is critical for excitation-contraction coupling and requires auxiliary proteins like junctophilin (JPH). JPHs are targets for disease-associated mutations, most notably hypertrophic cardiomyopathy mutations in the JPH2 isoform. Here we provide high-resolution snapshots of JPH, both alone and in complex with a calcium channel peptide, and show how this interaction is targeted by cardiomyopathy mutations.
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Affiliation(s)
- Zheng Fang Yang
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Pankaj Panwar
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Ciaran R. McFarlane
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Wietske E. Tuinte
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, 6020 Austria
| | - Marta Campiglio
- Institute of Physiology, Medical University of Innsbruck, Innsbruck, 6020 Austria
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The Life Sciences Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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27
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Abstract
Microtubules are essential cytoskeletal elements found in all eukaryotic cells. The structure and composition of microtubules regulate their function, and the dynamic remodeling of the network by posttranslational modifications and microtubule-associated proteins generates diverse populations of microtubules adapted for various contexts. In the cardiomyocyte, the microtubules must accommodate the unique challenges faced by a highly contractile, rigidly structured, and long-lasting cell. Through their canonical trafficking role and positioning of mRNA, proteins, and organelles, microtubules regulate essential cardiomyocyte functions such as electrical activity, calcium handling, protein translation, and growth. In a more specialized role, posttranslationally modified microtubules form load-bearing structures that regulate myocyte mechanics and mechanotransduction. Modified microtubules proliferate in cardiovascular diseases, creating stabilized resistive elements that impede cardiomyocyte contractility and contribute to contractile dysfunction. In this review, we highlight the most exciting new concepts emerging from recent studies into canonical and noncanonical roles of cardiomyocyte microtubules.
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Affiliation(s)
- Keita Uchida
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| | - Emily A Scarborough
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| | - Benjamin L Prosser
- Department of Physiology, Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
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28
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Abstract
In mammalian cardiac myocytes, the plasma membrane includes the surface sarcolemma but also a network of membrane invaginations called transverse (t-) tubules. These structures carry the action potential deep into the cell interior, allowing efficient triggering of Ca2+ release and initiation of contraction. Once thought to serve as rather static enablers of excitation-contraction coupling, recent work has provided a newfound appreciation of the plasticity of the t-tubule network's structure and function. Indeed, t-tubules are now understood to support dynamic regulation of the heartbeat across a range of timescales, during all stages of life, in both health and disease. This review article aims to summarize these concepts, with consideration given to emerging t-tubule regulators and their targeting in future therapies.
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Affiliation(s)
- Katharine M Dibb
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom;
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
- K.G. Jebsen Centre for Cardiac Research, University of Oslo, Oslo Norway
| | - Andrew W Trafford
- Unit of Cardiac Physiology, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom;
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29
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Bang ML, Bogomolovas J, Chen J. Understanding the molecular basis of cardiomyopathy. Am J Physiol Heart Circ Physiol 2022; 322:H181-H233. [PMID: 34797172 PMCID: PMC8759964 DOI: 10.1152/ajpheart.00562.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 02/03/2023]
Abstract
Inherited cardiomyopathies are a major cause of mortality and morbidity worldwide and can be caused by mutations in a wide range of proteins located in different cellular compartments. The present review is based on Dr. Ju Chen's 2021 Robert M. Berne Distinguished Lectureship of the American Physiological Society Cardiovascular Section, in which he provided an overview of the current knowledge on the cardiomyopathy-associated proteins that have been studied in his laboratory. The review provides a general summary of the proteins in different compartments of cardiomyocytes associated with cardiomyopathies, with specific focus on the proteins that have been studied in Dr. Chen's laboratory.
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Affiliation(s)
- Marie-Louise Bang
- Institute of Genetic and Biomedical Research (IRGB), National Research Council (CNR), Milan Unit, Milan, Italy
- IRCCS Humanitas Research Hospital, Rozzano (Milan), Italy
| | - Julius Bogomolovas
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
| | - Ju Chen
- Division of Cardiovascular Medicine, Department of Medicine Cardiology, University of California, San Diego, La Jolla, California
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30
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Nusier M, Shah AK, Dhalla NS. Structure-Function Relationships and Modifications of Cardiac Sarcoplasmic Reticulum Ca2+-Transport. Physiol Res 2022; 70:S443-S470. [DOI: 10.33549/physiolres.934805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sarcoplasmic reticulum (SR) is a specialized tubular network, which not only maintains the intracellular concentration of Ca2+ at a low level but is also known to release and accumulate Ca2+ for the occurrence of cardiac contraction and relaxation, respectively. This subcellular organelle is composed of several phospholipids and different Ca2+-cycling, Ca2+-binding and regulatory proteins, which work in a coordinated manner to determine its function in cardiomyocytes. Some of the major proteins in the cardiac SR membrane include Ca2+-pump ATPase (SERCA2), Ca2+-release protein (ryanodine receptor), calsequestrin (Ca2+-binding protein) and phospholamban (regulatory protein). The phosphorylation of SR Ca2+-cycling proteins by protein kinase A or Ca2+-calmodulin kinase (directly or indirectly) has been demonstrated to augment SR Ca2+-release and Ca2+-uptake activities and promote cardiac contraction and relaxation functions. The activation of phospholipases and proteases as well as changes in different gene expressions under different pathological conditions have been shown to alter the SR composition and produce Ca2+-handling abnormalities in cardiomyocytes for the development of cardiac dysfunction. The post-translational modifications of SR Ca2+ cycling proteins by processes such as oxidation, nitrosylation, glycosylation, lipidation, acetylation, sumoylation, and O GlcNacylation have also been reported to affect the SR Ca2+ release and uptake activities as well as cardiac contractile activity. The SR function in the heart is also influenced in association with changes in cardiac performance by several hormones including thyroid hormones and adiponectin as well as by exercise-training. On the basis of such observations, it is suggested that both Ca2+-cycling and regulatory proteins in the SR membranes are intimately involved in determining the status of cardiac function and are thus excellent targets for drug development for the treatment of heart disease.
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Affiliation(s)
| | | | - NS Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen, Research Centre, 351 Tache Avenue, Winnipeg, MB, R2H 2A6 Canada.
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Dixon RE. Nanoscale Organization, Regulation, and Dynamic Reorganization of Cardiac Calcium Channels. Front Physiol 2022; 12:810408. [PMID: 35069264 PMCID: PMC8769284 DOI: 10.3389/fphys.2021.810408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 11/30/2021] [Indexed: 12/19/2022] Open
Abstract
The architectural specializations and targeted delivery pathways of cardiomyocytes ensure that L-type Ca2+ channels (CaV1.2) are concentrated on the t-tubule sarcolemma within nanometers of their intracellular partners the type 2 ryanodine receptors (RyR2) which cluster on the junctional sarcoplasmic reticulum (jSR). The organization and distribution of these two groups of cardiac calcium channel clusters critically underlies the uniform contraction of the myocardium. Ca2+ signaling between these two sets of adjacent clusters produces Ca2+ sparks that in health, cannot escalate into Ca2+ waves because there is sufficient separation of adjacent clusters so that the release of Ca2+ from one RyR2 cluster or supercluster, cannot activate and sustain the release of Ca2+ from neighboring clusters. Instead, thousands of these Ca2+ release units (CRUs) generate near simultaneous Ca2+ sparks across every cardiomyocyte during the action potential when calcium induced calcium release from RyR2 is stimulated by depolarization induced Ca2+ influx through voltage dependent CaV1.2 channel clusters. These sparks summate to generate a global Ca2+ transient that activates the myofilaments and thus the electrical signal of the action potential is transduced into a functional output, myocardial contraction. To generate more, or less contractile force to match the hemodynamic and metabolic demands of the body, the heart responds to β-adrenergic signaling by altering activity of calcium channels to tune excitation-contraction coupling accordingly. Recent accumulating evidence suggests that this tuning process also involves altered expression, and dynamic reorganization of CaV1.2 and RyR2 channels on their respective membranes to control the amplitude of Ca2+ entry, SR Ca2+ release and myocardial function. In heart failure and aging, altered distribution and reorganization of these key Ca2+ signaling proteins occurs alongside architectural remodeling and is thought to contribute to impaired contractile function. In the present review we discuss these latest developments, their implications, and future questions to be addressed.
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Affiliation(s)
- Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, United States
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Abstract
Junctophilins (JPHs) comprise a family of structural proteins that connect the plasma membrane to intracellular organelles such as the endo/sarcoplasmic reticulum. Tethering of these membrane structures results in the formation of highly organized subcellular junctions that play important signaling roles in all excitable cell types. There are four JPH isoforms, expressed primarily in muscle and neuronal cell types. Each JPH protein consists of 6 'membrane occupation and recognition nexus' (MORN) motifs, a joining region connecting these to another set of 2 MORN motifs, a putative alpha-helical region, a divergent region exhibiting low homology between JPH isoforms, and a carboxy-terminal transmembrane region anchoring into the ER/SR membrane. JPH isoforms play essential roles in developing and maintaining subcellular membrane junctions. Conversely, inherited mutations in JPH2 cause hypertrophic or dilated cardiomyopathy, while trinucleotide expansions in the JPH3 gene cause Huntington Disease-Like 2. Loss of JPH1 protein levels can cause skeletal myopathy, while loss of cardiac JPH2 levels causes heart failure and atrial fibrillation, among other disease. This review will provide a comprehensive overview of the JPH gene family, phylogeny, and evolutionary analysis of JPH genes and other MORN domain proteins. JPH biogenesis, membrane tethering, and binding partners will be discussed, as well as functional roles of JPH isoforms in excitable cells. Finally, potential roles of JPH isoform deficits in human disease pathogenesis will be reviewed.
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Affiliation(s)
- Stephan E Lehnart
- Cellular Biophysics and Translational Cardiology Section, Heart Research Center Göttingen, University Medical Center Göttingen, Department of Cardiology and Pneumology, Georg-August University Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States; Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), Neuroscience, and Center for Space Medicine, Baylor College of Medicine, Houston, Texas, United States
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Perni S. The Builders of the Junction: Roles of Junctophilin1 and Junctophilin2 in the Assembly of the Sarcoplasmic Reticulum–Plasma Membrane Junctions in Striated Muscle. Biomolecules 2022; 12:biom12010109. [PMID: 35053257 PMCID: PMC8774113 DOI: 10.3390/biom12010109] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 02/06/2023] Open
Abstract
Contraction of striated muscle is triggered by a massive release of calcium from the sarcoplasmic reticulum (SR) into the cytoplasm. This intracellular calcium release is initiated by membrane depolarization, which is sensed by voltage-gated calcium channels CaV1.1 (in skeletal muscle) and CaV1.2 (in cardiac muscle) in the plasma membrane (PM), which in turn activate the calcium-releasing channel ryanodine receptor (RyR) embedded in the SR membrane. This cross-communication between channels in the PM and in the SR happens at specialized regions, the SR-PM junctions, where these two compartments come in close proximity. Junctophilin1 and Junctophilin2 are responsible for the formation and stabilization of SR-PM junctions in striated muscle and actively participate in the recruitment of the two essential players in intracellular calcium release, CaV and RyR. This short review focuses on the roles of junctophilins1 and 2 in the formation and organization of SR-PM junctions in skeletal and cardiac muscle and on the functional consequences of the absence or malfunction of these proteins in striated muscle in light of recently published data and recent advancements in protein structure prediction.
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Affiliation(s)
- Stefano Perni
- Department of Physiology and Biophysics, Anschutz Medical Campus, University of Colorado, Aurora, CO 80045, USA
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Kansakar U, Varzideh F, Jankauskas SS, Gambardella J, Trimarco B, Santulli G. Advances in the understanding of excitation-contraction coupling: the pulsing quest for drugs against heart failure and arrhythmias. EUROPEAN HEART JOURNAL. CARDIOVASCULAR PHARMACOTHERAPY 2021; 7:e91-e93. [PMID: 34498676 DOI: 10.1093/ehjcvp/pvab069] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 08/24/2021] [Accepted: 09/07/2021] [Indexed: 11/14/2022]
Affiliation(s)
- Urna Kansakar
- Departments of Medicine (Cardiology) and Molecular Pharmacology, Einstein College of Medicine, Wilf Family Cardiovascular Research Institute, Einstein-Sinai Diabetes Research Center (ES-DRC), Fleisher Institute for Diabetes and Metabolism (FIDAM), Einstein Institute for Aging Research, 1300 Morris PARK AVENUE, New York City, 10461, NY, USA
| | - Fahimeh Varzideh
- Departments of Medicine (Cardiology) and Molecular Pharmacology, Einstein College of Medicine, Wilf Family Cardiovascular Research Institute, Einstein-Sinai Diabetes Research Center (ES-DRC), Fleisher Institute for Diabetes and Metabolism (FIDAM), Einstein Institute for Aging Research, 1300 Morris PARK AVENUE, New York City, 10461, NY, USA
| | - Stanislovas S Jankauskas
- Departments of Medicine (Cardiology) and Molecular Pharmacology, Einstein College of Medicine, Wilf Family Cardiovascular Research Institute, Einstein-Sinai Diabetes Research Center (ES-DRC), Fleisher Institute for Diabetes and Metabolism (FIDAM), Einstein Institute for Aging Research, 1300 Morris PARK AVENUE, New York City, 10461, NY, USA
| | - Jessica Gambardella
- Departments of Medicine (Cardiology) and Molecular Pharmacology, Einstein College of Medicine, Wilf Family Cardiovascular Research Institute, Einstein-Sinai Diabetes Research Center (ES-DRC), Fleisher Institute for Diabetes and Metabolism (FIDAM), Einstein Institute for Aging Research, 1300 Morris PARK AVENUE, New York City, 10461, NY, USA.,International Translational Research and Medical Education (ITME) Consortium and Department of Advanced Biomedical Sciences, "Federico II" University, Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Bruno Trimarco
- International Translational Research and Medical Education (ITME) Consortium and Department of Advanced Biomedical Sciences, "Federico II" University, Via Sergio Pansini, 5, 80131, Naples, Italy
| | - Gaetano Santulli
- Departments of Medicine (Cardiology) and Molecular Pharmacology, Einstein College of Medicine, Wilf Family Cardiovascular Research Institute, Einstein-Sinai Diabetes Research Center (ES-DRC), Fleisher Institute for Diabetes and Metabolism (FIDAM), Einstein Institute for Aging Research, 1300 Morris PARK AVENUE, New York City, 10461, NY, USA.,International Translational Research and Medical Education (ITME) Consortium and Department of Advanced Biomedical Sciences, "Federico II" University, Via Sergio Pansini, 5, 80131, Naples, Italy
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35
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Calpain-2 specifically cleaves Junctophilin-2 at the same site as Calpain-1 but with less efficacy. Biochem J 2021; 478:3539-3553. [PMID: 34524407 PMCID: PMC8589432 DOI: 10.1042/bcj20210629] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/17/2022]
Abstract
Calpain proteolysis contributes to the pathogenesis of heart failure but the calpain isoforms responsible and their substrate specificities have not been rigorously defined. One substrate, Junctophilin-2 (JP2), is essential for maintaining junctional cardiac dyads and excitation-contraction coupling. We previously demonstrated that mouse JP2 is cleaved by calpain-1 (CAPN1) between Arginine 565 (R565) and Threonine 566 (T566). Recently, calpain-2 (CAPN2) was reported to cleave JP2 at a novel site between Glycine 482 (G482) and Threonine 483 (T483). We aimed to directly compare the contributions of each calpain isoform, their Ca2+ sensitivity, and their cleavage site selection for JP2. We find CAPN1, CAPN2 and their requisite CAPNS1 regulatory subunit are induced by pressure overload stress that is concurrent with JP2 cleavage. Using in vitro calpain cleavage assays, we demonstrate that CAPN1 and CAPN2 cleave JP2 into similar 75 kD N-terminal (JP2NT) and 25 kD C-terminal fragments (JP2CT) with CAPNS1 co-expression enhancing proteolysis. Deletion mutagenesis shows both CAPN1 and CAPN2 require R565/T566 but not G482/T483. When heterologously expressed, the JP2CT peptide corresponding to R565/T566 cleavage approximates the 25 kD species found during cardiac stress while the C-terminal peptide from potential cleavage at G482/T483 produces a 35 kD product. Similar results were obtained for human JP2. Finally, we show that CAPN1 has higher Ca2+ sensitivity and cleavage efficacy than CAPN2 on JP2 and other cardiac substrates including cTnT, cTnI and β2-spectrin. We conclude that CAPN2 cleaves JP2 at the same functionally conserved R565/T566 site as CAPN1 but with less efficacy and suggest heart failure may be targeted through specific inhibition of CAPN1.
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36
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Setterberg IE, Le C, Frisk M, Li J, Louch WE. The Physiology and Pathophysiology of T-Tubules in the Heart. Front Physiol 2021; 12:718404. [PMID: 34566684 PMCID: PMC8458775 DOI: 10.3389/fphys.2021.718404] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/07/2021] [Indexed: 12/18/2022] Open
Abstract
In cardiomyocytes, invaginations of the sarcolemmal membrane called t-tubules are critically important for triggering contraction by excitation-contraction (EC) coupling. These structures form functional junctions with the sarcoplasmic reticulum (SR), and thereby enable close contact between L-type Ca2+ channels (LTCCs) and Ryanodine Receptors (RyRs). This arrangement in turn ensures efficient triggering of Ca2+ release, and contraction. While new data indicate that t-tubules are capable of exhibiting compensatory remodeling, they are also widely reported to be structurally and functionally compromised during disease, resulting in disrupted Ca2+ homeostasis, impaired systolic and/or diastolic function, and arrhythmogenesis. This review summarizes these findings, while highlighting an emerging appreciation of the distinct roles of t-tubules in the pathophysiology of heart failure with reduced and preserved ejection fraction (HFrEF and HFpEF). In this context, we review current understanding of the processes underlying t-tubule growth, maintenance, and degradation, underscoring the involvement of a variety of regulatory proteins, including junctophilin-2 (JPH2), amphiphysin-2 (BIN1), caveolin-3 (Cav3), and newer candidate proteins. Upstream regulation of t-tubule structure/function by cardiac workload and specifically ventricular wall stress is also discussed, alongside perspectives for novel strategies which may therapeutically target these mechanisms.
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Affiliation(s)
- Ingunn E Setterberg
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Christopher Le
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Michael Frisk
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - Jia Li
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway.,KG Jebsen Centre for Cardiac Research, University of Oslo, Oslo, Norway
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37
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Wright PT, Gorelik J, Harding SE. Electrophysiological Remodeling: Cardiac T-Tubules and ß-Adrenoceptors. Cells 2021; 10:cells10092456. [PMID: 34572106 PMCID: PMC8468945 DOI: 10.3390/cells10092456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 01/09/2023] Open
Abstract
Beta-adrenoceptors (βAR) are often viewed as archetypal G-protein coupled receptors. Over the past fifteen years, investigations in cardiovascular biology have provided remarkable insights into this receptor family. These studies have shifted pharmacological dogma, from one which centralized the receptor to a new focus on structural micro-domains such as caveolae and t-tubules. Important studies have examined, separately, the structural compartmentation of ion channels and βAR. Despite links being assumed, relatively few studies have specifically examined the direct link between structural remodeling and electrical remodeling with a focus on βAR. In this review, we will examine the nature of receptor and ion channel dysfunction on a substrate of cardiomyocyte microdomain remodeling, as well as the likely ramifications for cardiac electrophysiology. We will then discuss the advances in methodologies in this area with a specific focus on super-resolution microscopy, fluorescent imaging, and new approaches involving microdomain specific, polymer-based agonists. The advent of powerful computational modelling approaches has allowed the science to shift from purely empirical work, and may allow future investigations based on prediction. Issues such as the cross-reactivity of receptors and cellular heterogeneity will also be discussed. Finally, we will speculate as to the potential developments within this field over the next ten years.
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Affiliation(s)
- Peter T. Wright
- School of Life & Health Sciences, University of Roehampton, Holybourne Avenue, London SW15 4JD, UK;
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Julia Gorelik
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
| | - Sian E. Harding
- Cardiac Section, National Heart and Lung Institute (NHLI), Faculty of Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK;
- Correspondence:
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38
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Hamilton S, Terentyev D. RyR2 Gain-of-Function and Not So Sudden Cardiac Death. Circ Res 2021; 129:417-419. [PMID: 34292783 DOI: 10.1161/circresaha.121.319651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Shanna Hamilton
- Department of Physiology and Cell Biology, The Ohio State University, Columbus. Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus
| | - Dmitry Terentyev
- Department of Physiology and Cell Biology, The Ohio State University, Columbus. Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus
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39
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Gilani N, Wang K, Muncan A, Peter J, An S, Bhatti S, Pandya K, Zhang Y, Tang YD, Gerdes AM, Stout RF, Ojamaa K. Triiodothyronine maintains cardiac transverse-tubule structure and function. J Mol Cell Cardiol 2021; 160:1-14. [PMID: 34175303 DOI: 10.1016/j.yjmcc.2021.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 06/03/2021] [Accepted: 06/18/2021] [Indexed: 12/29/2022]
Abstract
Subclinical hypothyroidism and low T3 syndrome are commonly associated with an increased risk of cardiovascular disease (CVD) and mortality. We examined effects of T3 on T-tubule (TT) structures, Ca2+ mobilization and contractility, and clustering of dyadic proteins. Thyroid hormone (TH) deficiency was induced in adult female rats by propyl-thiouracil (PTU; 0.025%) treatment for 8 weeks. Rats were then randomized to continued PTU or triiodo-L-thyronine (T3; 10 μg/kg/d) treatment for 2 weeks (PTU + T3). After in vivo echocardiographic and hemodynamic recordings, cardiomyocytes (CM) were isolated to record Ca2+ transients and contractility. TT organization was assessed by confocal microscopy, and STORM images were captured to measure ryanodine receptor (RyR2) cluster number and size, and L-type Ca2+ channel (LTCC, Cav1.2) co-localization. Expressed genes including two integral TT proteins, junctophilin-2 (Jph-2) and bridging integrator-1 (BIN1), were analyzed in left ventricular (LV) tissues and cultured CM using qPCR and RNA sequencing. The T3 dosage used normalized serum T3, and reversed adverse effects of TH deficiency on in vivo measures of cardiac function. Recordings of isolated CM indicated that T3 increased rates of Ca2+ release and re-uptake, resulting in increased velocities of sarcomere shortening and re-lengthening. TT periodicity was significantly decreased, with reduced transverse tubules but increased longitudinal tubules in TH-deficient CMs and LV tissue, and these structures were normalized by T3 treatment. Analysis of STORM data of PTU myocytes showed decreased RyR2 cluster numbers and RyR localizations within each cluster without significant changes in Cav1.2 localizations within RyR clusters. T3 treatment normalized RyR2 cluster size and number. qPCR and RNAseq analyses of LV and cultured CM showed that Jph2 expression was T3-responsive, and its increase with treatment may explain improved TT organization and RyR-LTCC coupling.
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Affiliation(s)
- Nimra Gilani
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Kaihao Wang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA; Department of Cardiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Adam Muncan
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Jerrin Peter
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Shimin An
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA; Department of Cardiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Simran Bhatti
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Khushbu Pandya
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Youhua Zhang
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Yi-Da Tang
- Department of Cardiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - A Martin Gerdes
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Randy F Stout
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA; NYIT Imaging Center, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
| | - Kaie Ojamaa
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Northern Blvd., Old Westbury, New York 11568, USA.
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40
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Striated Preferentially Expressed Protein Kinase (SPEG) in Muscle Development, Function, and Disease. Int J Mol Sci 2021; 22:ijms22115732. [PMID: 34072258 PMCID: PMC8199188 DOI: 10.3390/ijms22115732] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/23/2021] [Accepted: 05/25/2021] [Indexed: 02/06/2023] Open
Abstract
Mutations in striated preferentially expressed protein kinase (SPEG), a member of the myosin light chain kinase protein family, are associated with centronuclear myopathy (CNM), cardiomyopathy, or a combination of both. Burgeoning evidence suggests that SPEG plays critical roles in the development, maintenance, and function of skeletal and cardiac muscles. Here we review the genotype-phenotype relationships and the molecular mechanisms of SPEG-related diseases. This review will focus on the progress made toward characterizing SPEG and its interacting partners, and its multifaceted functions in muscle regeneration, triad development and maintenance, and excitation-contraction coupling. We will also discuss future directions that are yet to be investigated including understanding of its tissue-specific roles, finding additional interacting proteins and their relationships. Understanding the basic mechanisms by which SPEG regulates muscle development and function will provide critical insights into these essential processes and help identify therapeutic targets in SPEG-related disorders.
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41
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Yang L, Li RC, Xiang B, Li YC, Wang LP, Guo YB, Liang JH, Wang XT, Hou T, Xing X, Zhou ZQ, Ye H, Feng RQ, Lakatta EG, Chai Z, Wang SQ. Transcriptional regulation of intermolecular Ca 2+ signaling in hibernating ground squirrel cardiomyocytes: The myocardin-junctophilin axis. Proc Natl Acad Sci U S A 2021; 118:e2025333118. [PMID: 33785600 PMCID: PMC8040632 DOI: 10.1073/pnas.2025333118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The contraction of heart cells is controlled by the intermolecular signaling between L-type Ca2+ channels (LCCs) and ryanodine receptors (RyRs), and the nanodistance between them depends on the interaction between junctophilin-2 (JPH2) in the sarcoplasmic reticulum (SR) and caveolin-3 (CAV3) in the transversal tubule (TT). In heart failure, decreased expression of JPH2 compromises LCC-RyR communication leading to deficient blood-pumping power. In the present study, we found that JPH2 and CAV3 transcription was concurrently regulated by serum response factor (SRF) and myocardin. In cardiomyocytes from torpid ground squirrels, compared with those from euthermic counterparts, myocardin expression was up-regulated, which boosted both JPH2 and CAV3 expression. Transmission electron microscopic imaging showed that the physical coupling between TTs and SRs was tightened during hibernation and after myocardin overexpression. Confocal Ca2+ imaging under the whole-cell patch clamp condition revealed that these changes enhanced the efficiency of LCC-RyR intermolecular signaling and fully compensated the adaptive down-regulation of LCCs, maintaining the power of heart contraction while avoiding the risk of calcium overload during hibernation. Our finding not only revealed an essential molecular mechanism underlying the survival of hibernating mammals, but also demonstrated a "reverse model of heart failure" at the molecular level, suggesting a strategy for treating heart diseases.
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Affiliation(s)
- Lei Yang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Rong-Chang Li
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Bin Xiang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yi-Chen Li
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Li-Peng Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yun-Bo Guo
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Jing-Hui Liang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Xiao-Ting Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Tingting Hou
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Xin Xing
- College of Life Science, Shenyang Normal University, Shenyang 110034, China
| | - Zeng-Quan Zhou
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Haihong Ye
- Beijing Key Laboratory of Neural Regeneration and Repair, Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Ren-Qing Feng
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, Baltimore, MD 21224
| | - Zhen Chai
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China
| | - Shi-Qiang Wang
- State Key Laboratory of Membrane Biology, College of Life Sciences, Peking University, Beijing 100871, China;
- Chinese Institute for Brain Research, Beijing 102206, China
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