Cardiac Niche Influences the Direct Reprogramming of Canine Fibroblasts into Cardiomyocyte-Like Cells

Figure 2

Viral transduction and exogenous gene expressions. (a) Schematic representation of the lentiviral vectors carrying the human sequence of the transcription factor genes (GATA4-MEF2C-TBX5-HAND2), the microdystrophin gene, and the GFP reporter gene. (b) The GFP reporter gene under the control of the α-MyHC promoter was already expressed 48 hours after transduction. (c) Fibroblasts underwent morphology changes 7 days after transduction and become flattened and binucleated cells expressing GFP. (d) Immunofluorescence analysis on GHMT CF alone (top left panel) and in coculture with neonatal rat cardiomyocytes (bottom left panel), with antibodies against GFP (green) and myosin heavy chain (red), shows double positive cells and single positive cells for GFP (right panel). (e) Cell growth curve after transduction shows a decrease of cell proliferation (/cell type). (f) Fold induction of microdystrophin (μdys) mRNA expression in transduced cells compared to the control; , CF and SF versus controls (CF and SF transduced with empty vector). (g) Exogenous transcription factors expression () after transduction shows high induction levels during the 28 days of differentiation.