Effect Of Bdnf And Bfgf On Endogenous Nscs In Rats With Global Cerebral Ischemia-reperfusion

OBJECTIVEStudy the effect of BDNF and bFGF on endogenous neural stem cell proliferation, migration and differentiation in rats with global brain ischemia-reperfusion.MethodsMale Sprague-Dawley rats (250 g～300 g) were divided into five groups:sham operation group (A, n=12), operation group (B, n=24), BDNF group (C, n=24), bFGF group (D, n=24), BDNF and bFGF group (E, n=24). The global brain ischemia-reperfusion models were established, and then the BDNF, bFGF, BDNF and bFGF mixed liquor was injected into the lateral ventricle in group C, D, E, respectively. The doses of 5μl (0.1μg/μl) was administrated before the model operation, and once every two days after operation. The saline was used in group A. The rat brains were acquired at 3rd d,7th d,11th d,15th d with intraperitoneal injection of BrdU 1 d before animal sacrifice. HE and immunohistochemistry were used to observe the pathological changes and the expression of BrdU and Nestin in cerebral hippocampus and cortex. RT-PCR was used to measure the NSE mRNA in brain tissue. SPSS 13.0 software was used in this study. The analysis of variance and student's t test were used to analyze the measurement date. All date were expressed as Mean±SD, and P<0.05 was considered as significant difference.Results(1) HE staining:In sham group, the neurons had a regular arrangement and normal shape. In model group, the neurons were sparse with larger intercellular space. There were a lot of degenerated and necrotic neurons and the bodies were shrunken with karyopycnosis and chromatospherite vanished. In group C, D and E, the number of survival neurons was increased.(2) Immunohistochemistry:In group A, there were few positive cells in hippocampus and cerebral cortex. Compared with group A, the expression of BrdU and Nestin was increased significantly at 3rd day in B, C, D, E group, peaked at 7th day in B group and at 11th day in C, D, E group, then began to decrease. Compared with model group, the number of BrdU-positive and Nestin-positive cells were increased significantly at each time point in group C, D, E (P<0.05). There was no significant difference between group C and D (P<0.05). Compared with group C and D, the BrdU and Nestin-positive cells were increased apparently significantly in group E (P<0.05).(3) RT-PCR:The content of NSE mRNA in group B, C, D, E was study before the 11th day, but increased at 15th day. Only group D and E were increased significantly (P<0.05).Conclusions(1) The proliferation of endogenous neural stem cells in situ can be induced by global cerebral ischemia and reperfusion.(2) The proliferation of endogenous neural stem cells in situ can be promoted and extended by Global cerebral ischemia and reperfusion of rat. Combination of BDNF and bFGF expressed a synergistic interaction with promoting the neurogenesis of hippocampus and cerebral cortex in the global cerebral ischemia and reperfusion of rats. (3) bFGF has better effect than BDNF on promoting endogenous neural stem cells differentiated into neurons. Combination of BDNF and bFGF has more significant effect.