The Effect Of Nerve Growth Factor On The Expression Of Fas Protein And Cell Apoptosis In The Hippocampus Following Cerebral Ischemia And Reperfusion In Rats

ObjectiveThe necrosis and cell apoptosis in neurons is an important pathological process following cerebral ischemia/reperfusion. The importance of the effect of apoptosis has been paid more attention to. It is a reversible course, which is distinguished from necrosis. It is assumed that the volume of infarction can be reduced by inhabiting apoptosis. The route of Fas/FasL is of importance in apoptosis. The binding of Fas and FasL promotes the process of apoptosis of nerve cells after cerebral ischemia. The gene, fas, is one of the most important genes promoting apoptosis. Nerve Growth Factor (NGF) is a kind of modulating factor nutrient to nerve . Delayed neuronal death (DND) can be reduced by providing NGF, which can protect neurons. There are few reports on whether NGF can reduce apoptosis by down-regulating the expression of Fas protein.In this study, we will examine the expression of Fas protein in hippocampus CA1 region by immunohistochemistry staining, and detect apoptosis by TUNEL method. We will analyze the result in order to supply theoretic basis for comprehensive treatment.Method1 Experimental subjects: 30 Wistar rats ,weighing 160-220 grams, is divided into 2 groups randomly, 15 for each group, which are NS controlled group and NGF group after cerebral ischemia/reperfusion. There are 3 subgroups in each group according to the time of reperfusion.2 Agents: Fas and TUNEL agent, NGF.3 Model: The ischemia/reperfusion model is established by clipping bilateral cervical arteries for 30 minutes, and then removing the clips to achieve reperfusion .4 Method: The expression of Fas protein in hippocampus CA1 region is examined by immunohistochemistry staining. Apoptosis is detected by TUNEL method. The difference of the expression of Fas protein between groups is compared by the method of t-test. The difference of the percentage of apoptosis is compared by the method of x~2-test.Results1 The average optical density (AOD) of Fas protein in hippocampus CA1 region is lower in NGF group than in NS group at 6h and 24h after reperfusion(P<0. 001, P<0. 05, respectively ). It showed no difference of the AOD at 48h after reperfusion (P>0.5).2 The percentage of apoptosis in hippocampus CA1 region is lower in NGF group than in NS group at 6h ,24h and 48h after reperfusion(P<0.005).Conclusion1 NGF can down-regulate the expression of Fas protein in hippocampus CA1 region after reperfusion.2 NGF can reduce the rate of apoptosis in hippocampus CA1 region after reperfusion to achieve the protective effect.