Lentivirus-mediated p75 neurotrophin receptor silencing combined with nerve growth factor overexpression promotes proliferation of rat bone marrow mesenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND: P75 Neurotrophin receptor (P75NTR) is one of the receptors for nerve growth factor (NGF). P75NTR plays a dual role in promoting proliferation or apoptosis in various cell tissues, and is highly expressed at fracture nonunion sites. However, excessive NGF can shut down P75NTR receptor, thereby saving damaged cells. Therefore, the study regarding co-transfection of silenced P75NTR and NGF overexpression is of great significance for the proliferation of bone marrow mesenchymal stem cells and provides new ideas for clinical treatment of fracture nonunion. OBJECTIVE: To observe the effect of lentivirus-mediated silencing of P75NTR combined with NGF overexpression on the proliferation of bone marrow mesenchymal stem cells in Sprague-Dawely rats. METHODS: Bone marrow mesenchymal stem cells from Sprague-Dawley rats were cultured to the third generation in vitro and were divided into blank control group, negative control group, silent p75NTR group, NGF overexpression group, and silent p75NTR combined with NGF overexpression group. Lentivirus-mediated silencing of P75NTR and overexpression of NGF were transfected into rat bone marrow mesenchymal stem cells to induce P75NTR silencing and NGF overexpression. Inverted fluorescence microscopy was used to observe changes in cell morphology on day 3 after transfection. Flow cytometry was used to detect transfection efficiency and western blot method was applied to detect the expression of P75NTR and NGF. Finally, the cell proliferation activity was detected by MTT method and cell counting kit-8 method. RESULTS AND CONCLUSION: Cell growth and distribution were good after co-transfection of lentivirus. The transfection efficiency of the double-gene lentiviral vector exceeded 70%. Compared with the blank control and negative control groups, the expression of P75NTR protein was significantly down-regulated, and the expression of NGF was profoundly up-regulated in the silent p75NTR combined with NGF overexpression group. Compared with the blank control and negative control groups, cell proliferation was significantly increased in the other three groups (P < 0.05), and the fastest proliferation was observed in the silent p75NTR combined with NGF overexpression group. To conclude, silencing P75NTR combined with NGF overexpression co-transfection can promote the proliferation of bone marrow mesenchymal stem cells from Sprague-Dawley rats.