Protective effects of bone marrow mesenchymal stem cells with stable expression of Bcl-2 on ischemia- hypoxia of hippocampal neurons

Abstract

The protective effect of bone marrow mesenchymal stem cells (MSCs) with stable expression of Bcl-2 on the in vitro ischemia-hypoxia of hippocampal neurons was investigated in the present study. Mouse Bcl-2 cDNA was amplified by RT-PCR followed by Lentivirus-mediated gene transfection into MSCs. Puromycin resistance was detected to screen MSCs undergoing successful transfection, and the mRNA expression of Bcl-2 was determined by RT-PCR. Serum and oxygen deprivation was performed in normal MSCs and those undergoing transfection aiming to mimic ischemia injury in vitro, and flow cytometry was used to detect the apoptosis rate of these cells. Neurogenic induction of Bcl-2 expressing MSCs was carried out followed by detection of neuron markers. The rat hippocampal neurons were isolated from neonate rats. The Bcl-2 expressing MSCs and hippocampal neurons were cocultured, and the protective effect of Bcl-2 expressing MSCs on the ischemia-hypoxia of hippocampal neurons was observed. Following transfection, MSCs had stable and efficient expression of Bcl-2 after screening. When compared with normal MSCs, the number of apoptotic Bcl-2 expressing cells was significantly decreased and that of survival cells markedly increased after serum and oxygen deprivation. In addition, the Bcl-2 expressing MSCs had the potent differentiation into neurons. In the coculture system, Bcl-2 expressing MSCs could remarkably reduce the apoptosis rate of hippocampal neurons after ischemia-hypoxia (P < 0.01). The MSCs undergoing Bcl-2 transfection had stable Bcl-2 expression, which can protect them from serum and oxygen deprivation induced apoptosis and protect hippocampal neuron against ischemia-hypoxia induced apoptosis in vitro. Furthermore, the Bcl-2 transfecion does not affect the differentiation of MSCs into neurons.