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

Figure 7

Sarcomeric protein expression of bone marrow-derived PBCs. (a) MSCs cultured with CCM but unexposed to BIX01294 or (b–f) PBCs collected from BIX01294 plus CCM-treated MSCs were subsequently treated with dexamethasone and aggregated as a hanging drop prior to dual fluorescent staining with antibody (gray) and DAPI (blue). (a) Individual control culture showing titin and DAPI staining. Note the absence of gray signal indicating that non-BIX01294-treated control cultures were not labeled with the titin antibody. (b) In contrast, BIX01294 induced PBCs showed widespread titin expression when placed under differentiation conditions. (c) High magnification view of aggregated PBC cultures stained for titin, which on close-up view of the boxed region (d) indicated that titin protein was becoming organized within the cells (arrows). (e) Muscle α-actinin was also broadly distributed in MSC-derived PBC cultures, (f) which at higher magnification showed evidence of becoming organized (arrows). Scale bar = 20 μm.

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