ABSTRACT
BACKGROUND: Our previous study demonstrated that bone marrow mesenchymal stem cells (MSCs) presented with a low survival rate and newly formed vascular-like structures was sparsely distributed in the local infarct tissues after cell transplantation, which certainly impaired the therapeutic efficacy. Long non-coding RNA-H19 (lncRNA-H19) has been confirmed to be associated with MSCs differentiation and mediate vascularization. OBJECTIVE:To observe the influence of lncRNA-H19 on the survival and vascularization potential of MSCs in vitro and to explore the possible mechanism. METHODS:MSCs were obtained and cultured in vitro.Cells were divided into five groups:MSCs+H19,MSCs+H19 negative control (MSCs+H19 NC), MSCs+si-H19, MSCs+si-H19 negative control (MSCs+si-H19 NC) and MSCs groups. MSCs+H19 and MSCs+H19 NC groups were transfected with lncRNA-H19 and lncRNA-H19 scramble RNA respectively, while MSCs+siH19 and MSCs+si-H19 NC groups were transfected with lncRNA-H19 siRNA and lncRNA-H19 siRNA scramble respectively. Cells were cultured under hypoxic-ischemic condition (serum-free medium, 1% O2) for 24 hours. Then, cell proliferation and apoptosis were evaluated using MTS and TUNEL, respectively. Cell supernatant from each experimental group was further co-cultured with human umbilical vein endothelial cells to induce vascularization. The expression of vascular endothelial growth factor A (VEGFA) was thereafter detected using western blot assay. RESULTS AND CONCLUSION: Compared with MSCs+H19 NC and MSCs groups, MSCs+H19 group presented with significantly higher proliferation rate, lower apoptosis percentage and a larger number of vascular branches on matrigel (P < 0.01). There was a significantly higher expression of VEGFA in the MSCs+H19 group than MSCs+H19 NC and MSCs groups. Compared with the MSCs and MSCs+si-H19 NC groups, MSCs+H19 group presented with significantly lower proliferation rate, higher apoptosis percentage and a less number of vascular branches on matrigel (P < 0.01). In addition, VEGFA expression was distinctly downregulated in the MSCs+si-H19 group in comparison with the MSCs+si-H19 NC and MSCs groups. These findings indicate that lncRNA-H19 effectively promotes MSCs survival and vascularization under hypoxic-ischemic condition in vitro,and this effect may be associated with the upregulation of VEGFA.
ABSTRACT
BACKGROUND:Our previous work demonstrated that bone marrow mesenchymal stem cells (BMSCs) transplantation could improve cardiac function in rats with myocardial infarction.However,the overall efficacy was unsatisfactory,and there was a low efficiency of BMSCs differentiating into cardiomyocytes in the local infarct myocardium.OBJECTIVE:To transfect long non-coding RNA-Braveheart (IncRNA-Bvht) into BMSCs in order to observe whether it could promote cardiomyocyte differentiation of BMSCs in vitro.METHODS:pLVX-IRES-ZsGreen1-IncRNA-Bvht vector was constructed and applied to transfect IncRNA-Bvht into bMSCs,and then,the transfection efficiency was detected.BMSCs were obtained from C57BL/6 mice and cultured ir vitro.Passage 3 cells were divided into three groups:BMSCs group,null vector group and IncRNA-Bvht group.All cells in the three groups were cultured in the normal condition for 48 hours and cardiomyocytes differentiation was induced by 5-azacytidine for another 24 hours followed by 2-week culture under normal conditions.Cardiomyocyte differentiation of BMSCs was observed under fluorescence microscopy and expression of cardiac specific cell markers including troponin T and myosin were examined using immunofluorescent staining,western blot assay,and qRT-PCR.RESULTS AND CONCLUSION:Cell morphological changes could be observed in all the groups 2 weeks after the induction.Interconnected cells arranged consistently in all the three groups.Immunofiuorescent staining results showed that the expression of troponin T and myosin was notably positive,and the proportion of troponin T positive cells was significantly increased.qRT-PCR and western blot assay results indicated that there were significantly increased levels of troponin T and myosin in the IncRNA-Bvht group as compared with the BMSCs and null vector groups (P ＜ 0.01),suggesting that IncRNA-Bvht could efficiently promote cardiomyocyte differentiation of BMSCs in vitro.