Inhibition of Histone Methyltransferase, Histone Deacetylase, and β-Catenin Synergistically Enhance the Cardiac Potential of Bone Marrow Cells

Figure 5

Cardiac differentiation of MSCs following treatment with BIX01294±TSA. (a), (b) MSCs were immunostained for titin (green) and DAPI counterstained (blue), after 7 day incubation with Wnt11, following pretreatment with (a) BIX01294 or (b) BIX01294+TSA. (c)–(f) Coculture of CFSE vital dye-labeled MSCs (red) with neonatal rat cardiomyocytes that were immunostained for α-actinin (green) and DAPI counterstained (blue). (c) MSCs that were nontreated prior to coincubation with rat myocytes did not display cardiac phenotypes, as indicated by cells that exhibited only the red vital dye (arrowheads). (d)–(f) In contrast, MSCs pretreated with BIX01294 label showed evidence of cardiac differentiation when in proximity to the rat myocytes. (d) While the majority of MSCs in these later cultures remained nondifferentiated, as indicated by the sole display of the red vital dye (arrowheads), individual BIX01294-treated MSCs were observed that exhibited dual red and green fluorescence (arrow). (e), (f) Higher-magnification view of this coculture shown in the successive panels for both the vital dye fluorescence and actinin immunostaining or vital dye-label only indicates that the red and green colabeled MSC-derived cell (arrow) exhibits α-actinin in a striated pattern. Scale bar = 25 μm.

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