title: Reprogramming of human fibroblasts toward a cardiac fate.
abstract: Reprogramming of mouse fibroblasts toward a myocardial cell fate by forced expression of cardiac transcription factors or microRNAs has recently been demonstrated. The potential clinical applicability of these findings is based on the minimal regenerative potential of the adult human heart and the limited availability of human heart tissue. An initial but mandatory step toward clinical application of this approach is to establish conditions for conversion of adult human fibroblasts to a cardiac phenotype. Toward this goal, we sought to determine the optimal combination of factors necessary and sufficient for direct myocardial reprogramming of human fibroblasts. Here we show that four human cardiac transcription factors, including GATA binding protein 4, Hand2, T-box5, and myocardin, and two microRNAs, miR-1 and miR-133, activated cardiac marker expression in neonatal and adult human fibroblasts. After maintenance in culture for 4-11 wk, human fibroblasts reprogrammed with these proteins and microRNAs displayed sarcomere-like structures and calcium transients, and a small subset of such cells exhibited spontaneous contractility. These phenotypic changes were accompanied by expression of a broad range of cardiac genes and suppression of nonmyocyte genes. These findings indicate that human fibroblasts can be reprogrammed to cardiac-like myocytes by forced expression of cardiac transcription factors with muscle-specific microRNAs and represent a step toward possible therapeutic application of this reprogramming approach.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Nam
authors.forename: Kunhua
authors.initials: K
authors.lastname: Song
authors.forename: Xiang
authors.initials: X
authors.lastname: Luo
authors.forename: Edward
authors.initials: E
authors.lastname: Daniel
authors.forename: Kaleb
authors.initials: K
authors.lastname: Lambeth
authors.forename: Katherine
authors.initials: K
authors.lastname: West
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Hill
authors.forename: J Michael
authors.initials: JM
authors.lastname: DiMaio
authors.forename: Linda A
authors.initials: LA
authors.lastname: Baker
authors.forename: Rhonda
authors.initials: R
authors.lastname: Bassel-Duby
authors.forename: Eric N
authors.initials: EN
authors.lastname: Olson
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D054338:Cell Transdifferentiation / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology*; D005434:Flow Cytometry; D050991:GATA4 Transcription Factor / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D035683:MicroRNAs / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology*; D010641:Phenotype; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D050991:GATA4 Transcription Factor; D035683:MicroRNAs; C484170:GATA4 protein, human; C498765:HAND2 protein, human; C544547:MIRN1 microRNA, human; C548234:MIRN133 microRNA, human