Ischemic cardiac tissue conditioned media induced differentiation of human mesenchymal stem cells into early stage cardiomyocytes

Abstract

Mesenchymal stem cells (MSCs) are multipotent, can be easily expanded in culture and hence are an attractive therapeutic tool for cardiac repair. MSCs have tremendous potential to transdifferentiate to cardiac lineage both in vitro and in vivo. The present study examined the differentiation capacity of conditioned media derived from ischemic cardiac tissue on human MSCs. Human Bone marrow-derived MSCs after due characterization by immunocytochemistry and flow cytometry for MSC specific markers were induced by culture media derived from ischemic (n = 13) and non-ischemic (n = 18) human cardiac tissue. Parallel cultures were treated with 5-azacytidine (5-azaC), a potent cardiomyogen. MSCs induced with ischemic conditioned media formed myotube like structures, expressed sarcomeric Troponin I, alpha myosin heavy chain proteins and were positive for cardiac specific markers (Nkx2.5, human atrial natriuretic peptide, myosin light chain-2a, GATA-4) as was observed in 5-azaC treated cells. However, uninduced MSCs as well as those induced with non-ischemic cardiac conditioned media still maintained the fibroblast morphology even after 3 weeks post-induction. Transmission electron microscopic studies of cardiomyocyte-like cells derived from MSCs revealed presence of sarcomeric bands but failed to show gap junctions and intercalated discs as of adult cardiomyocytes. These findings demonstrate that ischemic cardiac conditioned media induces morphological and molecular changes in MSCs with cardiac features, but at a primitive stage. Proteomics analysis of the ischemic conditioned media revealed differential expression of three relevant proteins (C-type lectin superfamily member 13, Testis-specific chromodomain protein Y2 and ADP/ATP translocase 1), whose exact role in cardiac regeneration needs further analysis.

5-azacytidine promotes terminal differentiation of hepatic progenitor cells

“…Concomitantly, it was found that hepatic-associated markers of HP14.5 cells treated with 5-azaC alone, did not increase significantly, suggesting that DNA hypomethylation is not the only factor that determines gene expression during the hepatic cell differentiation process; the appropriate induced culture conditions and the microenvironment also have an effect on transcriptional control. Similarly, MSCs may be induced to differentiate into cardiomyocytes by 5-azaC, although it is difficult to to obtain functional beating myocardial cells (51). DLK and AFP proteins are markers of hepatic stem cells (52,53).…”

Mesenchymal stem cells in cardiac regeneration: a detailed progress report of the last 6 years (2010–2015)

“…MSCs induced with ischaemic cardiac conditioned media showed positive reaction for GATA-4 , Nkx 2.5 and MLC-2a , suggesting cardiomyogenic differentiation of MSCs, as compared with the negligible effect by a non-ischaemic environment exerted on the MSCs [ 247 ]. Cardiomyogenic media-primed MSCs enhanced expressions of sarcomeric α-actinin and Cx-43 , establishing themselves as better therapeutic agents than direct MSC transplantation [ 248 ].…”

Innate immunity and cardiomyocytes in ischemic heart disease

“…Thus, this study demonstrated the function of cardiomyocyte LOX-1 in immune responses. In the conditioned media derived from ischemic human cardiac tissue, which induced differentiation of human mesenchymal stem cells into early stage cardiomyocytes, C-type lectin superfamily member 13 (Clecsf13) was identified by a proteomics analysis as one of the three differentially expressed proteins (Ramesh et al, 2012). Although the exact role of Clecsf13 in cardiac regeneration needs further analysis, its differential expression in ischemic media at least suggests a role of Clecsf13 in myocardial ischemia.…”