Objective To construct recombinant plasmid that can inhibit acetyltransferase Gcn5 expression through RNA interference

then transfect it into MSCs induced by 5-azacytidine (5-aza)

and analyze the role of acetylases in the process of MSCs differentiation.   Methods MSCs were isolated from bilateral thigh bones and tibias of Wistar rats

then treated with 5-aza. Gcn5 shRNA recombinant plasmid vector was transfected into MSCs via lipofectin. The expressions of Gcn5

myosin heavy chain (MHC) and Connexin 43 (Cx43) were investigated by Western blot.   Results Under electron microscope

MSCs transfected with Gcn5 shRNA recombinant plasmid displayed obvious heterochromatin

but MSCs and MSCs transfected HK plasmid showed euchromatin. The expressions of Gcn5

Cx43 and MHC decreased significantly after Gcn5 shRNA recombinant plasmid transfection. Taking β-actin as inner criterion

the silent ratio of Gcn5

MHC and Cx43 were 86%

58% and 67%

respectively.   Conclusion The Gcn5 shRNA plasmids we constructed block acetylation during the process of MSCs differentiation into cardiomyocytes. Acetylation plays a very important role in the regulation of MSCs differentiation.