Investigation Of The Relationship Between Cathepsin L-mediated Apoptosis And ERK1/2 Signaling Pathway After Cerebral Ischemia-reperfusion In Rat

ObjectiveA lot of research finds that Cathepsin L and ERK1/2 signal pathways participate in reperfusion injury. But about the mechanisms between them and their relationship has not been fully elucidated. This experiment to detect Apoptosis related proteins of brain ischemia model about Cathepsin L and p-ERK1/2 protein expression, at the same time observe the cerebral infarction volume. The purpose is to discuss relationship between Cathepsin L and ERK1/2 signal pathways.MethodsThe 72 rats rat ages 10 to 12 weeks, weight 260-300 g were randomly divided into the following three groups: no surgery group(n=12), model group(n=30), Z-FY-DMK intervention group(n=30), the model group and Z-FY-DMK intervention group were divided into 2h group(n=6),6h group(n=6),12 h group(n=6) and 24 h group(n=12). Choose modified Longa line plug method to make model of ischemia-reperfusion injury. Intervention group, no surgery group and model group,the former lateral ventricle puncture injection Z-FY-DMK(10 mu mol/L), he latter two are injected physiological of the same volume. Longa ’s standard evaluation method: TTC staining method, the Western blot method were Involved in the detection methods of the experiment.Results1. A total of 86 clean level and healthy male rats were used, 72 was successful.2. The scores of neurologic deficits : no surgery group 0, the scores of Z-FY-DMK intervention group was significantly lower than model group at the same time point(P < 0.05).3. Results of TTC:No surgery group did not find infarcts,relative infarction volume of Z-FY-DMK intervention group was significantly decreased compared with the model group(P <0.05).4. Test results of Western blot:expression of Cathepsin L and p- ERK1/2 protein in model group after cerebral ischemia reperfusion 2h、 6h、12h is on the rise, and 12 h reaches the peak, compared with no surgery group, there is significant difference(P< 0.05); Z-FY-DMK intervention group compared with model group, Cathepsin L expression is reduced, p-ERK1/2 expression increased(p < 0.05), relative grey value of caspase-3 expression in no surgery group, model group(24h), Z-FY-DMK intervention group(24h) had significant difference(P < 0.05).Conclusions1. Cathepsin L mediated and participated in cell apoptosis may be though inhibiting ERK1/2 pathways.2. Z-FY-DMK had nerve protective effect.