Abstract:

BACKGROUND: Previous studies have confirmed that RhoA gene plays an important role in nerve damages. To decrease its expression by gene silencing can effectively block secondary nerve damages. RhoA protein mediated neurite growth inhibitory effect is an important reason for affecting repair effect following bone marrow mesenchymal stem cells (BMSCs) transplantation.
OBJECTIVE: To determine whether the RhoA gene silencing in BMSCs can enhance curative effects of transplantation by vein of BMSCs on cerebral infarction in rats.
METHODS: BMSCs were cultured by the suspension culture in vitro, and were transfected by siRNA to knock down the expression of RhoA gene. Western blot assay was used to assess the knockdown efficiency. The models of cerebral infarction were made by middle cerebral artery occlusion and randomly divided into three groups. RhoA gene silencing of BMSCs suspension, BMSCs suspension and medium without stem cells (control group) were respectively injected via caudal vein. The neurological defect scores were determined at 24 hours, 3 days and 1, 2 weeks after injection. The rats were sacrificed at 2 weeks following model induction. Histological changes in infarct regions were observed using immunohistochemistry and hematoxylin-eosin staining.
RESULTS AND CONCLUSION: The expression of RhoA was markedly knocked down by transfection of siRNA at 24 hours after the transfection (P=0.002). Therapeutic effects of BMSCs transplantation following RhoA gene silencing were significantly increased in histology and function. These suggest that RhoA gene in BMSCs can be silenced by RNA interference. BMSCs of RhoA gene silencing transplanted by caudal vein into the cerebral infarction tissues can survive, proliferation, differentiate and migrate in damage sites, and significantly improve the neurological function in rats with cerebral infarction.