ABSTRACT
BACKGROUND: There is few studies addressing the long-playing dynamic observation of cysteinyl aspartate specific protease 3 (Caspase-3) expression following cerebral ischemia/reperfusion.OBJECTIVE: To investigate the effect of transplantation of the neural stem cells (NSCs) modified with gene of glial cell line-derived neurotrophic factor (GDNF) on expression of Caspase-3 in adult Sprague Dawley rats with transient cerebral ischemia.DESING: Randomized controlled animal study.MATERIALS: Sixty Sprague Dawley rats were divided randomly into normal control group (N, n =5), ischemia/reperfusion group (IR, n=5), neural stem cell group (NSCs, n=25) and NSCs modified with gene of GDNF group (GDNF/NSCs, n =25). Several clean neonatal Sprague-Dawley rats were selected to harvest NSCs.METHODS: With the exception of normal control group, models of transient cerebral ischemia were created by modified suture method in other groups. At day 3 following reperfusion, 20 μL NSC suspension containing (4.0-5.0)×10~5 NSCs was infused into rats of the NSC group via right lateral ventricle. An equal volume of GDNF-modified NSC suspension was injected into rats of the GDNF/NSC group. 20 μL saline was infused into the rats of the ischemia/reperfusion group. Animals were anesthetized and sacrificed at week 1 following ischemia/reperfusion in the normal control and ischemia/reperfusion groups. Animals were anesthetized and sacrificed at weeks 1, 2, 3, 5, 7 following ischemia/reperfusion in the NSC and GDNF/NSC groups, 5 rats in each time point.MAIN OUTCOME MEASURES: The strept avidin-biotin immunostaining method was used to observe the distributive characteristics of Caspase-3 in the hippocampus and frontal parietal cortex.RESULTS: Immunohistochemical method (SP) showed that positive capase-3 products expressed in nucleus, cytoplasm and partial neurite. In hippocampus, number of Caspase-3-positive cells was decreased in NSC and GDNF/NSC groups. With the exception of at 1-week reperfusion, number of Caspase-3-positive cells was significantly lessened in the GDNF/NSC group compared with the NSC group at other time points (P < 0.05). In frontoparietal cortex, number of Caspase-3-positive cells was reduced in the NSC and GDNF/NSC groups over time. Except 1 and 2 weeks following ischemia/reperfusion, number of Caspase-3-positive cells was significantly lessened in the GDNF/NSC group compared with the NSC group (P < 0.05).CONCLUSION: Transplanting NSCs modified with gene of GDNF can improve remarkably neural function by deceasing Caspase-3 expression and reducing the nervous cell apoptosis. The transplantation of NSCs modified with gene of GDNF obtained better outcomes compared with NSC transplantation.