Inhibition of G9a Histone Methyltransferase Converts Bone Marrow Mesenchymal Stem Cells to Cardiac Competent Progenitors

Figure 3

BIX01294 promotes responsiveness to the cardiogenic stimulating protein Wnt11. MSCs were cultured nontreated or with 8 μM BIX01294 for 48 hrs prior to seven-day culture in fresh media with or without Wnt11. (a) Real-time qPCR analysis indicated that MSCs displayed significant upregulation of the primary cardiac transcription factors Nkx2.5, GATA4, and myocardin in response to Wnt11 when pretreated with BIX01294, as compared to cultures that were unexposed to BIX01294. In contrast, genes encoding for cardiac α-actin (Actc1), titin, muscle α-actinin (Actn2), and cTnI showed minimal to nondetectable increases in expression in response to BIX01294 plus Wnt11 treatments. . (b–d) However, immunofluorescent analysis did demonstrate that BIX01294 plus Wnt11 treatments promoted expression of muscle proteins (gray staining), as shown for (b) desmin and (c, d) α-actinin. Low magnification view of α-actinin in panel (c) illustrates that expression of muscle proteins was only displayed within small patches of cells as indicated by nuclear counterstaining with DAPI (blue). Scale bar = 20 μm.

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