Study On Neuroprotection Of RhG-CSF By Regulating Chaperone-mediated Autophagy In Ischemia-induced Neural Injury

BackgroundWith our country entering an aging society,the incidence of cerebrovascular disease has increased. Being the major disease of middle-aged and aged people, cerebrovascular disease has high morbidity, mortality and recurrence rate, which becomes a heavy burden to our society. In the cerebrovascular disease, cerebral infarction is also called ischemic stroke and accounts for60%-80%of cerebrovascular disease. The research of cerebral ischemia injury mechanisms and how to find effective methods of protection including related drug to reduce ischemia injury is the focus of clinical and scientific research. Now a lot of experiments demenstrate that restructuring human granulocyte colony stimulating factor(rhG-CSF) can protect brain in cerebral infarction, but its mechanism has not yet fully understood. Its protective effect is related to anti-apoptosis, anti-inflammation and promoting the mobilization of bone marrow stem cell into the damaged area of brain to differentiate into nerve cells. And it can promote angiogenesis and release neurotrophic factor. Autophagy is self-eating and it can degradate some virus, pathogen, error folded protein and damaged organelles,which plays a great important role in maintaining the normal function of human body. The research of blood and myocardial system has confirmed that rhG-CSF is related to autophagy. Autophagy plays a great role in differentiaion of blood cell and protection of myocardium. But the relations between autophagy and cerebral ischemic injury will be the focus of our research.AimIt is reported that rhG-CSF has protective effect in cerebral ischemia, but its mechanism has not yet fully understood. This experiment will discuss the relations between rhG-CSF and autophagy in both cell and animal experiment so as to detect the mechanisms of rhG-CSF. The relationship between rhG-CSF and autophagy will provide more theoretical basis for clinical application of rhG-CSF. MethodsPrepare SH-SY5Y cell hypoxia ischemia model and cells were cultured with rhG-CSF. Western blot was used to detect the expression of LAMP-2a and HSC-70. The expression of HSC-70was tested by Immunofluence. SD rats in good health were randomly divided into3groups:the sham operation group, MCAO operation group and experimental group. The line switch method was used to establish focal cerebral ischemia model (MCAO). Experimental group was given the rhG-CSF injection5days (50ug/kg-d). MCAO operation group was given equivalent physiological saline injection5days. The expression of LAMP-2a,HSC-70and MAP-2in brain tissue was tested by western blot and immunohistochemical method respectively. And use the NSS intelligent table to detect the neural function score of the three groups.ResultsHSC-70and LAMP-2a were obviously up-regulated dose-dependently in ischemia model cell cultured with rhG-CSF and the difference was statistically significant (p<0.05). In rats, the expression of LAMP-2a and HSC-70of MCAO operation group and experimental group were higher than sham operating group and the difference was statistically significant (p<0.05). Compared with MCAO operation group, experimental group had higher expression of LAMP-2a and HSC-70, the difference was statistically significant (p<0.05). Compared with sham operation group,MCAO operation group and experimental group had higher expression of MAP-2. Experimental group had higher expression of MAP-2than MCAO operation group. Nerve function score of experimental group and MCAO operation group was significantly higher than sham operation group and the difference was statistically significant (p<0.05).Nerve function score of experimental group was significantly lower than MCAO operation group and the difference was statistically significant (p <0.05).ConclusionRhG-CSF may play a protective role in ischemia-induced neural injury and its protective effect may be by increasing CMA.