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Shi X, Yao J, Huang Y, Wang Y, Jiang X, Wang Z, Zhang M, Zhang Y, Liu X. Hhatl ameliorates endoplasmic reticulum stress through autophagy by associating with LC3. J Biol Chem 2024; 300:107335. [PMID: 38705394 PMCID: PMC11143907 DOI: 10.1016/j.jbc.2024.107335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 04/24/2024] [Indexed: 05/07/2024] Open
Abstract
Endoplasmic reticulum (ER) stress, a common cellular stress response induced by various factors that interfere with cellular homeostasis, may trigger cell apoptosis. Autophagy is an important and conserved mechanism for eliminating aggregated proteins and maintaining protein stability of cells, which is closely associated with ER stress and ER stress-induced apoptosis. In this paper, we report for the first time that Hhatl, an ER-resident protein, is downregulated in response to ER stress. Hhatl overexpression alleviated ER stress and ER stress induced apoptosis in cells treated with tunicamycin or thapsigargin, whereas Hhatl knockdown exacerbated ER stress and apoptosis. Further study showed that Hhatl attenuates ER stress by promoting autophagic flux. Mechanistically, we found that Hhatl promotes autophagy by associating with autophagic protein LC3 (microtubule-associated protein 1A/1B-light chain 3) via the conserved LC3-interacting region motif. Noticeably, the LC3-interacting region motif was essential for Hhatl-regulated promotion of autophagy and reduction of ER stress. These findings demonstrate that Hhatl ameliorates ER stress via autophagy activation by interacting with LC3, thereby alleviating cellular pressure. The study indicates that pharmacological or genetic regulation of Hhatl-autophagy signaling might be potential for mediating ER stress and related diseases.
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Affiliation(s)
- Xingjuan Shi
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China.
| | - Jiayu Yao
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Yexi Huang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Yushan Wang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Xuan Jiang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Ziwen Wang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Mingming Zhang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Yu Zhang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Xiangdong Liu
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
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2
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Cala SE, Carruthers NJ, Stemmer PM, Chen Z, Chen X. Activation of Ca 2+ transport in cardiac microsomes enriches functional sets of ER and SR proteins. Mol Cell Biochem 2024; 479:85-98. [PMID: 37036634 PMCID: PMC10786961 DOI: 10.1007/s11010-023-04708-0] [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: 02/07/2023] [Accepted: 03/12/2023] [Indexed: 04/11/2023]
Abstract
The importance of sarcoplasmic reticulum (SR) Ca2+-handling in heart has led to detailed understanding of Ca2+-release and re-uptake protein complexes, while less is known about other endoplasmic reticulum (ER) functions in the heart. To more fully understand cardiac SR and ER functions, we analyzed cardiac microsomes based on their increased density through the actions of the SR Ca2+-ATPase (SERCA) and the ryanodine receptor that are highly active in cardiomyocytes. Crude cardiac microsomal vesicles loaded with Ca oxalate produced two higher density subfractions, MedSR and HighSR. Proteins from 20.0 μg of MV, MedSR, and HighSR protein were fractionated using SDS-PAGE, then trypsinized from 20 separate gel pieces, and analyzed by LC-MS/MS to determine protein content. From 62,000 individual peptide spectra obtained, we identified 1105 different proteins, of which 354 were enriched ≥ 2.0-fold in SR fractions compared to the crude membrane preparation. Previously studied SR proteins were all enriched, as were proteins associated with canonical ER functions. Contractile, mitochondrial, and sarcolemmal proteins were not enriched. Comparing the levels of SERCA-positive SR proteins in MedSR versus HighSR vesicles produced a range of SR subfraction enrichments signifying differing levels of Ca2+ leak co-localized in the same membrane patch. All known junctional SR proteins were more enriched in MedSR, while canonical ER proteins were more enriched in HighSR membrane. Proteins constituting other putative ER/SR subdomains also exhibited average Esub enrichment values (mean ± S.D.) that spanned the range of possible Esub values, suggesting that functional sets of proteins are localized to the same areas of the ER/SR membrane. We conclude that active Ca2+ loading of cardiac microsomes, reflecting the combined activities of Ca2+ uptake by SERCA, and Ca2+ leak by RyR, permits evaluation of multiple functional ER/SR subdomains. Sets of proteins from these subdomains exhibited similar enrichment patterns across membrane subfractions, reflecting the relative levels of SERCA and RyR present within individual patches of cardiac ER and SR.
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Affiliation(s)
- Steven E Cala
- Department of Physiology, Wayne State University, Detroit, MI, 48201, USA.
| | | | - Paul M Stemmer
- Institute of Environmental Health Sciences, Wayne State University, Detroit, USA
| | - Zhenhui Chen
- Krannert Institute of Cardiology, Indiana University, Indianapolis, IN, USA
| | - Xuequn Chen
- Department of Physiology, Wayne State University, Detroit, MI, 48201, USA
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3
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Cala SE, Carruthers NJ, Stemmer PM, Chen Z, Chen X. Activation of Ca transport in cardiac microsomes enriches functional sets of ER and SR proteins. RESEARCH SQUARE 2023:rs.3.rs-2557992. [PMID: 36798315 PMCID: PMC9934757 DOI: 10.21203/rs.3.rs-2557992/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The importance of sarcoplasmic reticulum (SR) Ca-handling in heart has led to detailed understanding of Ca-release and re-uptake protein complexes, while less is known about other endoplasmic reticulum (ER) functions in the heart. To more fully understand cardiac SR and ER functions, we analyzed cardiac microsomes based on their increased density through the actions of the SR Ca-ATPase (SERCA) and the ryanodine receptor that are highly active in cardiomyocytes. Crude cardiac microsomal vesicles loaded with Ca oxalate produced two higher density subfractions, MedSR and HighSR. Analyses of protein enrichments from the 3 membrane preparations (crude microsomes, MedSR, and HighSR), showed that only a third of microsomal proteins in heart, or 354 proteins, were enriched ≥2.0-fold in SR. Previously studied SR proteins were all enriched, as were proteins associated with canonical ER functions. Contractile, mitochondrial, and sarcolemmal proteins were not enriched. Comparing the levels of SERCA-positive SR proteins in MedSR versus HighSR vesicles produced a range of SR subfraction enrichments signifying differing levels of Ca leak (ryanodine receptor) co-localized in the same membrane patch. All known junctional SR proteins were more enriched in MedSR, while canonical ER proteins were more enriched in HighSR membrane. Proteins from other putative ER/SR subdomains also showed characteristic distributions among SR subpopulations. We conclude that active Ca loading of cardiac microsomes, reflecting the combined activities of Ca uptake by SERCA, and Ca leak by RyR, permits evaluation of multiple functional ER/SR subdomains. Sets of proteins from these subdomains exhibited similar enrichment patterns across membrane subfractions, reflecting the relative levels of SERCA and RyR present within individual patches of cardiac ER and SR.
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4
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Liu C, Li R, Li Y, Lin X, Zhao K, Liu Q, Wang S, Yang X, Shi X, Ma Y, Pei C, Wang H, Bao W, Hui J, Yang T, Xu Z, Lai T, Berberoglu MA, Sahu SK, Esteban MA, Ma K, Fan G, Li Y, Liu S, Chen A, Xu X, Dong Z, Liu L. Spatiotemporal mapping of gene expression landscapes and developmental trajectories during zebrafish embryogenesis. Dev Cell 2022; 57:1284-1298.e5. [PMID: 35512701 DOI: 10.1016/j.devcel.2022.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 02/06/2022] [Accepted: 04/05/2022] [Indexed: 01/01/2023]
Abstract
A major challenge in understanding vertebrate embryogenesis is the lack of topographical transcriptomic information that can help correlate microenvironmental cues within the hierarchy of cell-fate decisions. Here, we employed Stereo-seq to profile 91 zebrafish embryo sections covering six critical time points during the first 24 h of development, obtaining a total of 152,977 spots at a resolution of 10 × 10 × 15 μm3 (close to cellular size) with spatial coordinates. Meanwhile, we identified spatial modules and co-varying genes for specific tissue organizations. By performing the integrated analysis of the Stereo-seq and scRNA-seq data from each time point, we reconstructed the spatially resolved developmental trajectories of cell-fate transitions and molecular changes during zebrafish embryogenesis. We further investigated the spatial distribution of ligand-receptor pairs and identified potentially important interactions during zebrafish embryo development. Our study constitutes a fundamental reference for further studies aiming to understand vertebrate development.
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Affiliation(s)
- Chang Liu
- BGI-Shenzhen, Shenzhen 518083, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Rui Li
- BGI-Shenzhen, Shenzhen 518083, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Young Li
- BGI-Shenzhen, Shenzhen 518083, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Xiumei Lin
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Kaichen Zhao
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qun Liu
- BGI-Shenzhen, Shenzhen 518083, China; BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | - Shuowen Wang
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Brain Research Institute, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, China
| | - Xueqian Yang
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xuyang Shi
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Yuting Ma
- BGI-Shenzhen, Shenzhen 518083, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenyu Pei
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Hui Wang
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Wendai Bao
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | | | - Tao Yang
- China National GeneBank, Shenzhen, Guangdong 518120, China
| | - Zhicheng Xu
- China National GeneBank, Shenzhen, Guangdong 518120, China
| | - Tingting Lai
- China National GeneBank, Shenzhen, Guangdong 518120, China
| | - Michael Arman Berberoglu
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | | | - Miguel A Esteban
- BGI-Shenzhen, Shenzhen 518083, China; Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; CAS Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cells and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Guangzhou 510530, China; Institute of Stem Cells and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
| | | | - Guangyi Fan
- BGI-Shenzhen, Shenzhen 518083, China; BGI-Qingdao, BGI-Shenzhen, Qingdao 266555, China
| | | | - Shiping Liu
- BGI-Shenzhen, Shenzhen 518083, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China
| | - Ao Chen
- BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen 2200, Denmark
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China; Guangdong Provincial Key Laboratory of Genome Read and Write, Shenzhen 518120, China.
| | - Zhiqiang Dong
- College of Biomedicine and Health, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; Brain Research Institute, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei 442000, China.
| | - Longqi Liu
- BGI-Shenzhen, Shenzhen 518083, China; Shenzhen Key Laboratory of Single-Cell Omics, Shenzhen 518083, China.
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Narumanchi S, Wang H, Perttunen S, Tikkanen I, Lakkisto P, Paavola J. Zebrafish Heart Failure Models. Front Cell Dev Biol 2021; 9:662583. [PMID: 34095129 PMCID: PMC8173159 DOI: 10.3389/fcell.2021.662583] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/06/2021] [Indexed: 01/02/2023] Open
Abstract
Heart failure causes significant morbidity and mortality worldwide. The understanding of heart failure pathomechanisms and options for treatment remain incomplete. Zebrafish has proven useful for modeling human heart diseases due to similarity of zebrafish and mammalian hearts, fast easily tractable development, and readily available genetic methods. Embryonic cardiac development is rapid and cardiac function is easy to observe and quantify. Reverse genetics, by using morpholinos and CRISPR-Cas9 to modulate gene function, make zebrafish a primary animal model for in vivo studies of candidate genes. Zebrafish are able to effectively regenerate their hearts following injury. However, less attention has been given to using zebrafish models to increase understanding of heart failure and cardiac remodeling, including cardiac hypertrophy and hyperplasia. Here we discuss using zebrafish to study heart failure and cardiac remodeling, and review zebrafish genetic, drug-induced and other heart failure models, discussing the advantages and weaknesses of using zebrafish to model human heart disease. Using zebrafish models will lead to insights on the pathomechanisms of heart failure, with the aim to ultimately provide novel therapies for the prevention and treatment of heart failure.
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Affiliation(s)
- Suneeta Narumanchi
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
| | - Hong Wang
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
| | - Sanni Perttunen
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
| | - Ilkka Tikkanen
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland.,Abdominal Center Nephrology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Päivi Lakkisto
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland.,Department of Clinical Chemistry and Hematology, University of Helsinki, Helsinki University Hospital, Helsinki, Finland
| | - Jere Paavola
- Unit of Cardiovascular Research, Minerva Foundation Institute for Medical Research, Biomedicum Helsinki, Helsinki, Finland
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6
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Shi X, Zhang Y, Gong Y, Chen M, Brand-Arzamendi K, Liu X, Wen XY. Zebrafish hhatla is involved in cardiac hypertrophy. J Cell Physiol 2021; 236:3700-3709. [PMID: 33052609 DOI: 10.1002/jcp.30106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 01/26/2023]
Abstract
Cardiac hypertrophy is a compensatory response to pathological stimuli, ultimately progresses to cardiomyopathy, heart failure, or sudden death. Although many signaling pathways have been reported to be involved in the hypertrophic process, it is still not fully clear about the underlying molecular mechanisms for cardiac hypertrophy. Hedgehog acyltransferase-like (Hhatl), a sarcoplasmic reticulum-resident protein, exhibits high expression in the heart and muscle. However, the biological role of Hhatl in the heart remains unknown. In this study, we first found that the expression level of Hhatl is markedly decreased in cardiac hypertrophy. We further studied the role of hhatla, homolog of Hhatl with the zebrafish model. The depletion of hhatla in zebrafish leads to cardiac defects, as well as an enhanced level of hypertrophic markers. Besides, we found that calcineurin signaling participates in hhatla depletion-induced cardiac hypertrophy. Together, these results demonstrate a critical role for hhatla in cardiac hypertrophy.
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Affiliation(s)
- Xingjuan Shi
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Yu Zhang
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Yijie Gong
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Mengying Chen
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Koroboshka Brand-Arzamendi
- Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Li Ka Shing Knowledge Institute, Toronto, Ontario, Canada
- Department of Medicine, Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - Xiangdong Liu
- School of Life Science and Technology, Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, China
| | - Xiao-Yan Wen
- Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Li Ka Shing Knowledge Institute, Toronto, Ontario, Canada
- Department of Medicine, Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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7
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Ehrlich KC, Baribault C, Ehrlich M. Epigenetics of Muscle- and Brain-Specific Expression of KLHL Family Genes. Int J Mol Sci 2020; 21:E8394. [PMID: 33182325 PMCID: PMC7672584 DOI: 10.3390/ijms21218394] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/02/2020] [Accepted: 11/06/2020] [Indexed: 02/07/2023] Open
Abstract
KLHL and the related KBTBD genes encode components of the Cullin-E3 ubiquitin ligase complex and typically target tissue-specific proteins for degradation, thereby affecting differentiation, homeostasis, metabolism, cell signaling, and the oxidative stress response. Despite their importance in cell function and disease (especially, KLHL40, KLHL41, KBTBD13, KEAP1, and ENC1), previous studies of epigenetic factors that affect transcription were predominantly limited to promoter DNA methylation. Using diverse tissue and cell culture whole-genome profiles, we examined 17 KLHL or KBTBD genes preferentially expressed in skeletal muscle or brain to identify tissue-specific enhancer and promoter chromatin, open chromatin (DNaseI hypersensitivity), and DNA hypomethylation. Sixteen of the 17 genes displayed muscle- or brain-specific enhancer chromatin in their gene bodies, and most exhibited specific intergenic enhancer chromatin as well. Seven genes were embedded in super-enhancers (particularly strong, tissue-specific clusters of enhancers). The enhancer chromatin regions typically displayed foci of DNA hypomethylation at peaks of open chromatin. In addition, we found evidence for an intragenic enhancer in one gene upregulating expression of its neighboring gene, specifically for KLHL40/HHATL and KLHL38/FBXO32 gene pairs. Many KLHL/KBTBD genes had tissue-specific promoter chromatin at their 5' ends, but surprisingly, two (KBTBD11 and KLHL31) had constitutively unmethylated promoter chromatin in their 3' exons that overlaps a retrotransposed KLHL gene. Our findings demonstrate the importance of expanding epigenetic analyses beyond the 5' ends of genes in studies of normal and abnormal gene regulation.
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Affiliation(s)
- Kenneth C. Ehrlich
- Center for Biomedical Informatics and Genomics, Tulane University Health Sciences Center, New Orleans, LA 70112, USA;
| | - Carl Baribault
- Center for Research and Scientific Computing (CRSC), Tulane University Information Technology, Tulane University, New Orleans, LA 70112, USA;
| | - Melanie Ehrlich
- Center for Biomedical Informatics and Genomics, Tulane Cancer Center, Hayward Genetics Program, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
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Bachmann C, Jungbluth H, Muntoni F, Manzur AY, Zorzato F, Treves S. Cellular, biochemical and molecular changes in muscles from patients with X-linked myotubular myopathy due to MTM1 mutations. Hum Mol Genet 2017; 26:320-332. [PMID: 28007904 DOI: 10.1093/hmg/ddw388] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/07/2016] [Indexed: 01/07/2023] Open
Abstract
Centronuclear myopathies are early-onset muscle diseases caused by mutations in several genes including MTM1, DNM2, BIN1, RYR1 and TTN. The most severe and often fatal X-linked form of myotubular myopathy (XLMTM) is caused by mutations in the gene encoding the ubiquitous lipid phosphatase myotubularin, an enzyme specifically dephosphorylating phosphatidylinositol-3-phosphate and phosphatidylinositol-3,5-bisphosphate. Because XLMTM patients have a predominantly muscle-specific phenotype a number of pathogenic mechanisms have been proposed, including a direct effect of the accumulated lipid on the skeletal muscle calcium channel ryanodine receptor 1, a negative effect on the structure of intracellular organelles and defective autophagy. Animal models knocked out for MTM1 show severe reduction of ryanodine receptor 1 mediated calcium release but, since knocking out genes in animal models does not necessarily replicate the human phenotype, we considered it important to study directly the effect of MTM1 mutations on patient muscle cells. The results of the present study show that at the level of myotubes MTM1 mutations do not dramatically affect calcium homeostasis and calcium release mediated through the ryanodine receptor 1, though they do affect myotube size and nuclear content. On the other hand, mature muscles such as those obtained from patient muscle biopsies exhibit a significant decrease in expression of the ryanodine receptor 1, a decrease in muscle-specific microRNAs and a considerable up-regulation of histone deacetylase-4. We hypothesize that the latter events consequent to the primary genetic mutation, are the cause of the severe decrease in muscle strength that characterizes these patients.
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Affiliation(s)
- Christoph Bachmann
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Basel University, Basel, Switzerland
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina Children's Hospital, St Thomas' Hospital, London, UK.,Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, UK.,Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King's College, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, Institute of Child Health, London, UK
| | - Adnan Y Manzur
- Dubowitz Neuromuscular Centre and MRC Centre for Neuromuscular Diseases, Institute of Child Health, London, UK
| | - Francesco Zorzato
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Basel University, Basel, Switzerland.,Department of Life Sciences, General Pathology section, University of Ferrara, Ferrara, Italy
| | - Susan Treves
- Departments of Biomedicine and Anesthesia, Basel University Hospital, Basel University, Basel, Switzerland.,Department of Life Sciences, General Pathology section, University of Ferrara, Ferrara, Italy
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9
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Organization of junctional sarcoplasmic reticulum proteins in skeletal muscle fibers. J Muscle Res Cell Motil 2015; 36:501-15. [DOI: 10.1007/s10974-015-9421-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/08/2015] [Indexed: 01/24/2023]
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