ABSTRACT
BACKGROUND: Stem cell factors are hypoxia-induced neural regeneration factors. They stimulate animals' neural regeneration.OBJECTIVE: To observe Nestin and stem cell factor mRNA expressions after ischemia/reperfusion injury in rat brain, and to analyze the time rule of the two.DESIGN: A randomized controlled animal experiment.SETTING: Department of Ultrasound Diagnosis, Affdiated Hospital of Qingdao University Medical College.MATERIALS: Thirty-six healthy female adult Sprague-Dawley (SD) rats were provided by the Shanghai Laboratory Animal Center, Chinese Academy of Science. Nestin and stem cell factor mRNA in situ hybridization kits and 3,3'-diaminobenzidine (DAB)kit were provided by Boster Bioengineering Co.,Ltd (Wuhan, China).METHODS: This study was performed at the Shangdong Key Laboratory for Prevention and Treatment of Encephalopathy from January to June 2005. Thirty-two rats were created into models of ischemia/reperfusion models by occluding left middle cerebral artery with suture. At ischemia 1.5 hours and reperfusion 2, 6, 12, 24 hours, 2, 3, 7, 14 days, 4 rats were separately used in order to observe the expressions of Nestin and stem cell factor mRNA. The other 4 rats were used for sham-operation,in which, suture insertion was omitted, and the other procedures were identical to experimental groups. The expressions of Nestin and stem cell factor mRNA were detected in the cortex, corpora striatum and paraventricular nucleus region in rat brain by in situ hybridization.MAIN OUTCOME MEASURES: Nestin and stem cell factor mRNA expressions in the cortex, corpora striatum and paraventricular nucleus region in rat brain.RESULTS: Thirty-six rats were included in the final analysis. Nestin mRNA and stem cell factor were weakly expressed in the cortex, corpora striatum and paraventricular nucleus region in rats of sham-operation group. After ischemia/reperfusion, Nestin mRNA expression at each time point was significandy higher in the experimental groups (except in the cortex at ischemia 1.5 hours and reperfusion 2 hours, in the corpora striatum at ischemia 1.5 hours and reperfusion 2 and 6 hours and in the paraventricular nucleus region at ischemia 1.5 hours and reperfusion 2, 6 hours and 14 days) than in the sham-operation group (P＜0.05). While stem cell factor mRNA expression at each time point was significandy higher in the experimental groups (except in the cortex at ischemia 1.5 hours and reperfusion 2,6 and 12 hours, in the corpora striatum at ischemia 1.5 hours and reperfusion 2 and 6 hours and in the paraventricular nucleus region at ischemia 1.5 hours and reperfusion 2 hours and 14 days) than in the sham-operation group (P＜0.05).CONCLUSION: The time rule of stem cell factor mRNA expression is basically the same as that of neural stem cell proliferation. It indicates that following cerebral ischemia/reperfusion, stem cell factor mRNA expression may promote the proliferation of neural stem cells.
ABSTRACT
Objective To observe the effects of expressions of neurocyte adhesion molecule (NCAM) and growth associated protein-43 (GAP-43) in neurological function recovery following cerebral ischemia-reperfusion in rats. Methods The model of focal ischemia-reperfusion in SD rat was induced by intraluminal middle cerebral artery (MCA) occlusion with a nylon monofilament suture. In situ hybridization (ISH) was performed to examine the expression of NCAM mRNA and GAP-43 mRNA at 2,12 h and 1,2,3,7,14 d after reperfusion and in sham-operated controls. Results There was no functional deficit and little expression of NCAM mRNA and GAP-43 mRNA in brain cells in rats of the sham-operated group. In the experimental group, NCAM mRNA expression was observed after reperfusion for 2 h in cortex and striatum and peaked at 12 h and was still higher at 7 d. The neurological function improved at reperfusion of 3 d~14 d compared to reperfusion 2 h. In the ischemic cortex and striatum, GAP-43 mRNA expression demonstrated "double-peak" at 12 h and 2 d after reperfusion, then decreased gradually to the level of sham-operated group at 14 d. Conclusion The increasing NCAM expression might be an important factor of the neural reparation and GAP-43 might enhance the neurological functional recovery with ischemic brain injury in rat.
ABSTRACT
Objective To study the gene expressions of nestin and stem cell factor(SCF)in neurons after ischemia-reperfusion injury in rat brain. Methods Thirty-six adult female rats were subject to left middle cerebral artery occlusion for 1.5h and different hours of reperfusion. In site hybridization was used to examine the expression of nestin and SCF mRNA in the rats subjected to 2h, 6h, 12h, 24h, 2d, 3d, 7d, 14d of reperfusion and sham-operation group (n=4). Results (1) Nestin expression in cortex, striatum and extraventricular zone was weak in the sham-operation group, and increased markedly in the ischemic hemisphere compared with sham-operation group except of reperfusion 2h in cortex, 2h, 6h in striatum, 2h, 6h and 14d in extraventricular zone. (2)SCF expression in cortex, striatum and extraventricular zone was weak in the sham-operation group, and increased markedly in the ischemic hemisphere compared with sham-operation group except of reperfusion 2h, 6h, 12h in cortex, 2h, 6h in striatum, 2h and 14d in extraventricular zone. Conclusion It is suggested that SCF expression might enhance the proliferation of neural stem cells following ischemia-reperfusion in rats.