Nesprin-1 plays an important role in the proliferation and apoptosis of mesenchymal stem cells

The aim of this study was to investigate the expression of nesprin-1 protein and its effects on rat bone marrow mesenchymal stem cells (MSCs). MSCs were cultured in DMEM and surface-associated antigens of MSCs were detected by flow cytometry. The protein expression of nesprin-1 was detected by immunofluorescence and western blot analysis. A lentiviral vector expressing small interfering RNA (siRNA) targeting nesprin-1 was constructed (LV-siNesprin-1) and the MSCs were subsequently transfected with this vector. Another group of MSCs was transfected with the LV-GFP vector and another group of untransfected cells was used as the controls (normal group). The protein expression level of nesprin-1 in the 3 groups of MSCs (LV-siNesprin-1, LV-GFP and normal group) was measured by western blot analysis. Cell proliferation was assessed by MTT assay, and the cell cycle and apoptosis were detected by flow cytometry. DAPI was used to stain the nucleus of the MSCs. The MSCs appeared spindle-shaped with irregular processes and were positive for CD90, CD29 and negative for CD45. Nesprin-1 protein was found in the nuclear membrane. The protein expression of nesprin-1 in the LV-siNesprin-1 group was lower than that in the LV-GFP (P=0.03) and normal group (P=0.028); this difference was significant (P<0.05). The cell proliferation of the MSCs transfected with LV-siNesprin-1 was reduced; the apoptotic rate was higher in the LV-siNesprin-1 group compared with the other 2 groups (LV-GFP and normal group) (P=0.032, P=0.025, respectively; P<0.05). The changes in the morphology of the nucleus in the LV-siNesprin-1 group included fusion and fragmentation. In conclusion, the data presented in this study indicate that nesprin-1 regulates the proliferation and apoptosis of MSCs; our results are consistent with those from previous studies. Thus, nesprin-1 protein plays an important role in the proliferation and apoptosis of MSCs.