Therapeutic effect of erythropoietin gene-modified bone marrow mesenchymal stem cell transplantation on rat cerebral infarction / 中国组织工程研究

ABSTRACT

BACKGROUND:Previous studies have shown that erythropoietin can protect neurons and promote nerve regeneration. OBJECTIVE:To explore the therapeutic effect of erythropoietin gene-modified bone marrow mesenchymal stem celltransplantation via caudal vein on rat cerebral infarction. METHODS:Western blot assay was used to identify the expression of exogenous erythropoietin in bone marrow mesenchymal stem cells. A model of middle cerebral artery occlusion was established in Wistar rats using thread method. And then, model rats were randomly divided into model group (PBS injection via the caudal vein), transplantation group (transplantation of bone marrow mesenchymal stem cellsuspension), erythropoietin group (transplantation of erythropoietin-transfected bone marrow mesenchymal stem cellsuspension). Neurologic function was assessed at 3 days, 1, 2, 3, 4 weeks after celltransplantation. Four weeks after transplantation, the rats were decapitated after anesthesia to take brain tissues for RT-PCR detection of Bcl-2/Bax gene expression. cellapoptosis was measured by TUNEL. Hematoxylin-eosin staining and fluorescence microscopy were employed to observe the survival and distribution of PKH26-labeled bone marrow mesenchymal stem cells. RESULTS AND CONCLUSION:Western blot results showed that erythropoietin-transfected bone marrow mesenchymal stem cells could express the erythropoietin in vitro. At 1, 2, 3, 4 weeks after transplantation, the neurological defect scores in the transplantation group and erythropoietin group were significantly lower than those in the model group (P<0.05, P<0.01). The expression of bcl-2 gene in the infarct region was significantly higher in the erythropoietin group than the transplantation and model groups (P<0.05), but the expression of bax was significantly decreased (P<0.05). In the erythropoietin group, the number of apoptotic cells was reduced, and the number of PKH26 positive cells was increased as compared with the other two groups (P<0.05). These findings indicate that the transplantation of erythropoietin-modified bone marrow mesenchymal stem cells via caudal vein can significantly improve the neurological function in the rats with cerebral infarction.