{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T15:20:57Z","timestamp":1787239257689,"version":"build-2736575974"},"reference-count":51,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T00:00:00Z","timestamp":1761523200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan","doi-asserted-by":"crossref","award":["21K08261 (AUH)"],"award-info":[{"award-number":["21K08261 (AUH)"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan","doi-asserted-by":"crossref","award":["23K05094 (SS)"],"award-info":[{"award-number":["23K05094 (SS)"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Keiryokai Research Foundation, Iwate Medical University, Japan","award":["136 (AUH)"],"award-info":[{"award-number":["136 (AUH)"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicines"],"abstract":"<jats:p>Background\/Objectives: Dilated cardiomyopathy (DCM) is a prevalent and life-threatening heart muscle disease often caused by titin (TTN) truncating variants (TTNtv). While TTNtvs are the most common genetic cause of heritable DCM, the precise downstream regulatory mechanisms linking TTN deficiency to cardiac dysfunction and maladaptive fibrotic remodeling remain incompletely understood. This study aimed to identify key epigenetic regulators of TTN-mediated gene expression and explore their potential as therapeutic targets, utilizing human patient data and in vitro models. Methods: We analyzed RNA sequencing (RNA-seq) data from left ventricles of non-failing donors and cardiomyopathy patients (DCM, HCM, PPCM) (GSE141910). To model TTN deficiency, we silenced TTN in human iPSC-derived cardiomyocytes (iPSC-CMs) and evaluated changes in cardiac function genes (MYH6, NPPA) and fibrosis-associated genes (COL1A1, COL3A1, COL14A1). We further tested the effects of TMP-195, a class IIa histone deacetylase (HDAC) inhibitor, and individual knockdowns of HDAC4\/5\/7\/9. Results: In both human patient data and the TTN knockdown iPSC-CM model, TTN deficiency suppressed MYH6 and NPPA while upregulating fibrosis-associated genes. Treatment with TMP-195 restored NPPA and MYH6 expression and suppressed collagen genes, without altering TTN expression. Among the HDACs tested, HDAC5 knockdown was most consistently associated with improved cardiac markers and reduced fibrotic gene expression. Co-silencing TTN and HDAC5 replicated these beneficial effects. Furthermore, the administration of TMP-195 enhanced the modulation of NPPA and COL1A1, though its impact on COL3A1 and COL14A1 was not similarly enhanced. Conclusions: Our findings identify HDAC5 as a key epigenetic regulator of maladaptive gene expression in TTN deficiency. Although the precise mechanisms remain to be clarified, the ability of pharmacological HDAC5 inhibition with TMP-195 to reverse TTN-deficiency-induced gene dysregulation highlights its promising translational potential for TTN-related cardiomyopathies.<\/jats:p>","DOI":"10.3390\/medicines12040026","type":"journal-article","created":{"date-parts":[[2025,10,28]],"date-time":"2025-10-28T11:47:19Z","timestamp":1761652039000},"page":"26","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["HDAC5 Inhibition as a Therapeutic Strategy for Titin Deficiency-Induced Cardiac Remodeling: Insights from Human iPSC Models"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6491-347X","authenticated-orcid":false,"given":"Arif Ul","family":"Hasan","sequence":"first","affiliation":[{"name":"Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachiko","family":"Sato","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mami","family":"Obara","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yukiko","family":"Kondo","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eiichi","family":"Taira","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Liu, T., Song, D., Dong, J., Zhu, P., Liu, J., Liu, W., Ma, X., Zhao, L., and Ling, S. (2017). Current Understanding of the Pathophysiology of Myocardial Fibrosis and Its Quantitative Assessment in Heart Failure. Front. Physiol., 8.","DOI":"10.3389\/fphys.2017.00238"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1097\/GIM.0b013e3181f2481f","article-title":"Clinical and Genetic Issues in Dilated Cardiomyopathy: A Review for Genetics Professionals","volume":"12","author":"Hershberger","year":"2010","journal-title":"Genet. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"36280","DOI":"10.31083\/RCM36280","article-title":"Classification, Diagnosis, and Prognosis of Cardiomyopathy: A Comprehensive Narrative Review","volume":"26","author":"Jin","year":"2025","journal-title":"Rev. Cardiovasc. Med."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1038\/s41572-019-0084-1","article-title":"Dilated Cardiomyopathy","volume":"5","author":"Schultheiss","year":"2019","journal-title":"Nat. Rev. Dis. Prim."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Micaglio, E., Monasky, M.M., Bernardini, A., Mecarocci, V., Borrelli, V., Ciconte, G., Locati, E.T., Piccoli, M., Ghiroldi, A., and Anastasia, L. (2021). Clinical Considerations for a Family with Dilated Cardiomyopathy, Sudden Cardiac Death, and a Novel TTN Frameshift Mutation. Int. J. Mol. Sci., 22.","DOI":"10.3390\/ijms22020670"},{"key":"ref_6","first-page":"e67489","article-title":"Titin As the Culprit Behind Dilated Cardiomyopathy: A Case Series of Three Cases and a Comprehensive Literature Review","volume":"16","author":"Panjiyar","year":"2024","journal-title":"Cureus"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1514","DOI":"10.1161\/CIRCRESAHA.121.318157","article-title":"The Complex and Diverse Genetic Architecture of Dilated Cardiomyopathy","volume":"128","author":"Hershberger","year":"2021","journal-title":"Circ. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e002436","DOI":"10.1161\/CIRCGEN.118.002436","article-title":"Mortality Risk Associated With Truncating Founder Mutations in Titin","volume":"12","author":"Jansen","year":"2019","journal-title":"Circ. Genom. Precis. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e175206","DOI":"10.1172\/JCI175206","article-title":"TTN Truncation Variants Produce Sarcomere-Integrating Proteins of Uncertain Functional Significance","volume":"134","author":"Hinson","year":"2024","journal-title":"J. Clin. Investig."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"e169753","DOI":"10.1172\/JCI169753","article-title":"Truncated Titin Is Structurally Integrated into the Human Dilated Cardiomyopathic Sarcomere","volume":"134","author":"Kellermayer","year":"2024","journal-title":"J. Clin. Investig."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Schlittler, M., Pramstaller, P.P., Rossini, A., and De Bortoli, M. (2023). Myocardial Fibrosis in Hypertrophic Cardiomyopathy: A Perspective from Fibroblasts. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms241914845"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1852","DOI":"10.1161\/CIRCULATIONAHA.120.052395","article-title":"Genetic and Phenotypic Landscape of Peripartum Cardiomyopathy","volume":"143","author":"Goli","year":"2021","journal-title":"Circulation"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Jolfayi, A.G., Kohansal, E., Ghasemi, S., Naderi, N., Hesami, M., MozafaryBazargany, M.H., Moghadam, M.H., Fazelifar, A.F., Maleki, M., and Kalayinia, S. (2024). Exploring TTN Variants as Genetic Insights into Cardiomyopathy Pathogenesis and Potential Emerging Clues to Molecular Mechanisms in Cardiomyopathies. Sci. Rep., 14.","DOI":"10.1038\/s41598-024-56154-7"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.yjmcc.2021.05.018","article-title":"The Role of Demethylases in Cardiac Development and Disease","volume":"158","author":"Davis","year":"2021","journal-title":"J. Mol. Cell. Cardiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1038\/s41467-017-02467-3","article-title":"Integrated Omics Dissection of Proteome Dynamics during Cardiac Remodeling","volume":"9","author":"Lau","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_16","first-page":"e81264","article-title":"Causes, Diagnosis, Treatment, and Prognosis of Cardiac Fibrosis: A Systematic Review","volume":"17","author":"BaniHani","year":"2025","journal-title":"Cureus"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"119186","DOI":"10.1016\/j.lfs.2021.119186","article-title":"Epigenetics-Based Therapeutics for Myocardial Fibrosis","volume":"271","author":"Li","year":"2021","journal-title":"Life Sci."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Pozo, M.R., Meredith, G.W., and Entcheva, E. (2022). Human IPSC-Cardiomyocytes as an Experimental Model to Study Epigenetic Modifiers of Electrophysiology. Cells, 11.","DOI":"10.3390\/cells11020200"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.jjcc.2016.10.004","article-title":"Evidence of Epigenetic Tags in Cardiac Fibrosis","volume":"69","author":"Grimaldi","year":"2017","journal-title":"J. Cardiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1016\/S0092-8674(02)00861-9","article-title":"Class II Histone Deacetylases Act as Signal-Responsive Repressors of Cardiac Hypertrophy","volume":"110","author":"Zhang","year":"2002","journal-title":"Cell"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1186\/s13023-023-02896-y","article-title":"HDAC5 Inhibition Attenuates Ventricular Remodeling and Cardiac Dysfunction","volume":"18","author":"Zhu","year":"2023","journal-title":"Orphanet J. Rare Dis."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Bai, L., Kee, H.J., Choi, S.Y., Seok, Y.M., Kim, G.R., Kee, S.J., Kook, H., and Jeong, M.H. (2021). HDAC5 Inhibition Reduces Angiotensin II-Induced Vascular Contraction, Hypertrophy, and Oxidative Stress in a Mouse Model. Biomed. Pharmacother., 134.","DOI":"10.1016\/j.biopha.2020.111162"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Desjardins, C.A., and Naya, F.J. (2016). The Function of the MEF2 Family of Transcription Factors in Cardiac Development, Cardiogenomics, and Direct Reprogramming. J. Cardiovasc. Dev. Dis., 3.","DOI":"10.3390\/jcdd3030026"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Materna, S.C., Sinha, T., Barnes, R.M., Lammerts van Bueren, K., and Black, B.L. (2018). Cardiovascular Development and Survival Require Mef2c Function in the Myocardial but Not the Endothelial Lineage. Dev. Biol., 445.","DOI":"10.1016\/j.ydbio.2018.12.002"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Muncie-Vasic, J.M., Sinha, T., Clark, A.P., Brower, E.F., Saucerman, J.J., Black, B.L., and Bruneau, B.G. (2025). MEF2C Controls Segment-Specific Gene Regulatory Networks That Direct Heart Tube Morphogenesis. Genes Dev.","DOI":"10.1101\/gad.352889.125"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1161\/CIRCRESAHA.120.317254","article-title":"Epigenomes of Human Hearts Reveal New Genetic Variants Relevant for Cardiac Disease and Phenotype","volume":"127","author":"Tan","year":"2020","journal-title":"Circ. Res."},{"key":"ref_27","first-page":"817","article-title":"Integrated Landscape of Cardiac Metabolism in End-Stage Human Nonischemic Dilated Cardiomyopathy","volume":"1","author":"Flam","year":"2022","journal-title":"Nat. Cardiovasc. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1260419","DOI":"10.1126\/science.1260419","article-title":"Tissue-Based Map of the Human Proteome","volume":"347","author":"Fagerberg","year":"2015","journal-title":"Science"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Hasan, A.U., Serada, S., Sato, S., Obara, M., Hirata, S., Nagase, Y., Kondo, Y., and Taira, E. (2024). KDM4B Histone Demethylase Inhibition Attenuates Tumorigenicity of Malignant Melanoma Cells by Overriding the P53-Mediated Tumor Suppressor Pathway. J. Cell. Biochem., 126.","DOI":"10.1002\/jcb.30643"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.bbrc.2017.03.001","article-title":"GPR120 in Adipocytes Has Differential Roles in the Production of Pro-Inflammatory Adipocytokines","volume":"486","author":"Hasan","year":"2017","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Hasan, A.U., Obara, M., Sato, S., Kondo, Y., and Taira, E. (2024). CD146\/MCAM Links Doxorubicin-Induced Epigenetic Dysregulation to the Impaired Fatty Acid Transportation in H9c2 Cardiomyoblasts. Biochem. Biophys. Res. Commun., 693.","DOI":"10.1016\/j.bbrc.2023.149370"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"e006832","DOI":"10.1161\/CIRCHEARTFAILURE.119.006832","article-title":"Clinical Phenotypes and Prognosis of Dilated Cardiomyopathy Caused by Truncating Variants in the TTN Gene","volume":"13","author":"Akhtar","year":"2020","journal-title":"Circ. Heart Fail."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Gi, W.T., Haas, J., Sedaghat-Hamedani, F., Kayvanpour, E., Tappu, R., Lehmann, D.H., Samani, O.S., Wisdom, M., Keller, A., and Katus, H.A. (2020). Epigenetic Regulation of Alternative MRNA Splicing in Dilated Cardiomyopathy. J. Clin. Med., 9.","DOI":"10.3390\/jcm9051499"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Tharp, C.A., Haywood, M.E., Sbaizero, O., Taylor, M.R.G., and Mestroni, L. (2019). The Giant Protein Titin\u2019s Role in Cardiomyopathy: Genetic, Transcriptional, and Post-Translational Modifications of TTN and Their Contribution to Cardiac Disease. Front. Physiol., 10.","DOI":"10.3389\/fphys.2019.01436"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e189335","DOI":"10.1172\/JCI189335","article-title":"Regulation of TTN as a Mechanism of and Treatment for Heart Failure","volume":"135","author":"Fullenkamp","year":"2025","journal-title":"J. Clin. Investig."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Stroik, D., Gregorich, Z.R., Raza, F., Ge, Y., and Guo, W. (2024). Titin: Roles in Cardiac Function and Diseases. Front. Physiol., 15.","DOI":"10.3389\/fphys.2024.1385821"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1161\/CIRCULATIONAHA.120.049997","article-title":"Reading Frame Repair of TTN Truncation Variants Restores Titin Quantity and Functions","volume":"145","author":"Romano","year":"2021","journal-title":"Circulation"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e170196","DOI":"10.1172\/JCI170196","article-title":"Truncated Titin Protein in Dilated Cardiomyopathy Incorporates into the Sarcomere and Transmits Force","volume":"134","author":"McAfee","year":"2024","journal-title":"J. Clin. Investig."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Han, Y., Nie, J., Wang, D.W., and Ni, L. (2022). Mechanism of Histone Deacetylases in Cardiac Hypertrophy and Its Therapeutic Inhibitors. Front. Cardiovasc. Med., 9.","DOI":"10.3389\/fcvm.2022.931475"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.1007\/s00018-017-2737-0","article-title":"Structure and Function of the Nppa\u2013Nppb Cluster Locus during Heart Development and Disease","volume":"75","author":"Man","year":"2018","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1038\/nature21409","article-title":"Class IIa HDAC Inhibition Reduces Breast Tumors and Metastases via Anti-Tumor Macrophages","volume":"543","author":"Guerriero","year":"2017","journal-title":"Nature"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Hu, T., Schreiter, F.C., Bagchi, R.A., Tatman, P.D., Hannink, M., and McKinsey, T.A. (2019). HDAC5 Catalytic Activity Suppresses Cardiomyocyte Oxidative Stress and NRF2 Target Gene Expression. J. Biol. Chem., 294.","DOI":"10.1074\/jbc.RA118.007006"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Wu, C.P., Lusvarghi, S., Wang, J.C., Hsiao, S.H., Huang, Y.H., Hung, T.H., and Ambudkar, S.V. (2019). The Selective Class IIa Histone Deacetylase Inhibitor TMP195 Resensitizes ABCB1- and ABCG2-Overexpressing Multidrug-Resistant Cancer Cells to Cytotoxic Anticancer Drugs. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21010238"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"F1015","DOI":"10.1152\/ajprenal.00405.2020","article-title":"Class IIa HDAC Inhibitor TMP195 Alleviates Lipopolysaccharide-Induced Acute Kidney Injury","volume":"319","author":"Zhang","year":"2020","journal-title":"Am. J. Physiol. Ren. Physiol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"3007","DOI":"10.1038\/s41467-023-38771-4","article-title":"HDAC9-Mediated Epithelial Cell Cycle Arrest in G2\/M Contributes to Kidney Fibrosis in Male Mice","volume":"14","author":"Zhang","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"e91068","DOI":"10.1172\/jci.insight.91068","article-title":"Reversal of Pathological Cardiac Hypertrophy via the MEF2-Coregulator Interface","volume":"2","author":"Wei","year":"2017","journal-title":"JCI Insight."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"952","DOI":"10.1161\/CIRCRESAHA.109.209007","article-title":"Modulation of Angiotensin II\u2013Mediated Cardiac Remodeling by the MEF2A Target Gene Xirp2","volume":"106","author":"McCalmon","year":"2010","journal-title":"Circ. Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4127","DOI":"10.1002\/ehf2.15009","article-title":"Genotype Is Associated with Left Ventricular Reverse Remodelling and Early Events in Recent-Onset Dilated Cardiomyopathy","volume":"11","author":"Kubanek","year":"2024","journal-title":"ESC Heart Fail."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"9152","DOI":"10.1074\/jbc.M510217200","article-title":"Myocyte Enhancer Factors 2A and 2C Induce Dilated Cardiomyopathy in Transgenic Mice","volume":"281","author":"Xu","year":"2006","journal-title":"J. Biol. Chem."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"e183353","DOI":"10.1172\/JCI183353","article-title":"Regulation of Sarcomere Formation and Function in the Healthy Heart Requires a Titin Intronic Enhancer","volume":"135","author":"Kim","year":"2024","journal-title":"J. Clin. Investig."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1016\/j.avsg.2023.04.008","article-title":"Vascular Biology of Arterial Aneurysms","volume":"94","author":"Costa","year":"2023","journal-title":"Ann. Vasc. Surg."}],"container-title":["Medicines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2305-6320\/12\/4\/26\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T05:34:11Z","timestamp":1761716051000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2305-6320\/12\/4\/26"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,27]]},"references-count":51,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["medicines12040026"],"URL":"https:\/\/doi.org\/10.3390\/medicines12040026","relation":{},"ISSN":["2305-6320"],"issn-type":[{"value":"2305-6320","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,27]]}}}