ABSTRACT
BACKGROUND: How to enhance the proliferative activity of bone marrow mesenchymal stem cells and make their proper effects after transplantation is an urgent problem to be solved. OBJECTIVE: To investigate the effects of different negative pressures on the proliferation of rat bone mesenchymal stem cells and vascular endothelial growth factor secretion level. METHODS: Passage 3 bone marrow mesenchymal stem cells were cultured under normal conditions (control group) or under intermittent negative pressures (-6.65, -13.3, -26.6 kPa), once for 2 hours, with an interval of 12 hours. At 12, 24, 36, 48, and 60 hours of culture, cell proliferation was detected using cell counting kit-8, and mRNA expression of vascular endothelial growth factor receptor was detected by RT-PCR. Based on the above results, we selected the optimal negative pressure condition and time (-26.6 kPa, 24 hours). Bone marrow mesenchymal stem cells were treated normally, under -26.6 kPa or treated with Axitinib under -26.6 kPa. We detected the cell proliferation by cell counting kit-8, EDU cell positive rate by EDU kit, and cell colony forming unit by crystal violet staining thereafter. RESULTS AND CONCLUSION: Compared with the control group, the negative pressure groups had significantly increased cell proliferation, significantly increased vascular endothelial growth factor levels, and significantly up-regulated mRNA expression of vascular endothelial growth factor receptor (all P < 0.05). After being treated with Axitinib, the absorbance value of cell proliferation, the number of clone forming units and the rate of EDU positive cells in the negative pressure groups were markedly decreased. To conclude, in vitro negative pressure culture may promote the proliferation of mesenchymal stem cells through upregulation of vascular endothelial growth factor expression.