title: Ultrastructural maturation of human bone marrow mesenchymal stem cells-derived cardiomyocytes under alternative induction of 5-azacytidine.
abstract: Adult cardiomyocytes lack the ability to proliferate and are unable to repair damaged heart tissue, therefore differentiation of stem cells to cardiomyocytes represents an exceptional opportunity to study cardiomyocytes in vitro and potentially provides a valuable source for replacing damaged tissue. However, characteristic maturity of the in vitro differentiated cardiomyocytes and methods to achieve it are yet to be optimized. In this study, differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs) into cardiomyocytes is accomplished and the process investigated ultrastructurally. The hBM-MSCs were alternatively treated with 5 μM of 5-azacytidine (5-aza) for 8 weeks resulting in differentiation to cardiomyocytes. Expressions of cardiomyocyte-specific genes [cardiac α-actinin, cardiac β-myosin heavy chain (MHC) and connexin-43] and proteins (cardiac α-actinin, cardiac troponin and connexin-43) were confirmed in a time-dependent manner from the first to the fifth weeks post-induction. Ultrastructural maturation of hBM-MSCs-derived cardiomyocyte (MSCs-CM) corresponded with increase in number and organization of myofilaments in cells over time. Starting from week five, organized myofibrils along with developing sarcomeres were detectable. Later on, MSCs-CM were characterized by the presence of sarcoplasmic reticulum, T-tubules and diads as cardiomyocytes connected to each other by intercalated disc-like structures. Here, we showed the potential of hBM-MSCs as a source for the production of cardiomyocytes and confirmed mature ultrastructural characteristics of these cells using our alternative incubation method.
authors.affiliation: Department of Biology and Anatomical Sciences, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Piryaei
authors.forename: Masoud
authors.initials: M
authors.lastname: Soleimani
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Heidari
authors.forename: Mona
authors.initials: M
authors.lastname: Saheli
authors.forename: Razieh
authors.initials: R
authors.lastname: Rohani
authors.forename: Mohammadali
authors.initials: M
authors.lastname: Almasieh
mesh_terms: D000185:Actinin / Q000378:metabolism; D000328:Adult; D001374:Azacitidine / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D024722:Cardiac Myosins / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D018995:Myosin Heavy Chains / Q000378:metabolism; D014336:Troponin / Q000378:metabolism
chemical_list: D018031:Connexin 43; C500216:GJA1 protein, human; C501641:MYH7 protein, human; D014336:Troponin; D000185:Actinin; D024722:Cardiac Myosins; D018995:Myosin Heavy Chains; D001374:Azacitidine
keywords: 5-azacytidine; bone marrow mesenchymal stem cells; cardiomyocytes; differentiation; ultrastructure