摘要

The purpose of this study was to investigate whether autologous transplantation of adipose-derived mesenchymal stem cells (ADMSCs) has a neuroprotective effect against cerebral ischemia/reperfusion (I/R) injury in rats and to explore the possible underlying mechanisms. Adult male Sprague-Dawley rats were randomly assigned into the sham, I/R injury model (I/R), and model plus autologous transplantation of ADMSCs (ADMSC) groups. Cerebral I/R injury was induced by 2 h middle cerebral artery occlusion (MCAO) followed by reperfusion for 24 h. Rats in the I/R and ADMSC groups were intravenously injected with culture medium and ADMSCs (2.0x10(6)), respectively, at the onset of reperfusion and 12 h after reperfusion. Cerebral infarct volume was detected by triphenyltetrazolium chloride (TTC) staining. The histopathological changes and neuronal apoptosis in the ischemic penumbra were evaluated with H&E staining and the TUNEL assay, respectively. The nitric oxide (NO) content, caspase-3 activity and the Bax/Bcl-2 protein ratio were also measured. Moreover, the inducible nitric oxide synthase (iNOS) expression in the ischemic regions of rats was determined by immunohistochemical staining, quantitative real-time RT-PCR and western blot analysis. We found that autologous transplantation of ADMSCs significantly reduced the cerebral infarct volume, improved the I/R injury-induced brain damages and inhibited the neuronal apoptosis. ADMSC implantation also decreased caspase-3 activity and the Bax/Bcl-2 protein ratio, and markedly downregulated the expression of iNOS and thus prevented NO release in response to cerebral I/R injury. Taken together, our results demonstrated that autologous transplantation of ADMSCs can protect the brain against cerebral I/R injury via the inhibition of neuronal apoptosis and iNOS expression.