关键词: 骨髓间充质干细胞, 心肌细胞, GATA-4, 共培养

Abstract: Objective To investigate whether overexpression of GATA-4 increases adult mesenchymal stromal cell (MSC) transdifferentiation into a cardiac phenotype in vitro. Methods MSCs and cardiomyocytes (CMs) were isolated and cultured. MSCs were transduced with GATA-4 (MSCGATA-4) at the third passage. Gene expression in MSCGATA-4 was analyzed using real-time quantitative polymerase chain reaction (real-time PCR) and Western blot and immunohistochemistry. After co-cultured with CM for one week, the expression of cardiac genes of MSCGATA-4, including brain natriuretic peptide (BNP), Islet-1 and α -sarcomeric actinin, was determined by real-time PCR and Western blot. After mixed coculture with CM for one week, the beating of MSC was observed. MSC were examined α-actinin by for immunohistochemistry and the transdifferentiation rate of MSC was calculated directly from ?ow cytometery. Results Compared with control cells that were transfected with Green Fluorescent Protein (GFP) only (MSCNull), MSCGATA-4 were shown by immuno?uorescence, real-time PCR, and Western blot to have higher expression of GATA-4. After cocultured for one week, the mRNA and protein expression of cardiac genes, including BNP, Islet-1 and α -sarcomeric actinin, was up-regulated in MSCGATA-4 compared with MSCNull (P<0.05). After mixed coculture for one week, some MSCs beated and some MSCs were positive for α-actinin staining. The transdifferentiation rate was signi?cantly higher in MSCGATA-4 than MSCNul (P<0.05). Conclusions Overexpression of GATA-4 signi?cantly increases MSC differentiation into a myocardial phenotype and expressing BNP, Islet-1 and α-actinin.

Key words: bone marrow mesenchymal stem cells, cardiomyocytes, GATA-4, coculture