Neuroprotective Effect Of Resveratrol Via Attenuates Neuronal Autophagy And Neuroinflammation In A Rat Model Of Traumatic Brain Injury

Obiectives This study was applied with electronic controlled cortical impact injury method to reproduced TBI model in male SD rats.And we detect the change of expression of LC3,Beclin1,P62,TNF-α and IL-1β by Wstern blot in the injured side of hippocampus.The aim of our study is to research the mechanism underlying neuroprotective effect of resveratrol after TBI,and we hope to provide a new drug for the TBI patients to improve nerve function.Methods We divided 200 male SD rats into three groups randomly: 1 Sham group;2 TBI group;3 RV group.TBI models were reproduced according to the e CCI injury method.The TBI model was built with CCI method.Furthermore,we killed the rats at 12 h,24 h and 48 h following TBI,and we detect the following indexes: 1 The pathological histology and morphological changes of brain tissue were observed by H﹠E stains.2The expression of LC3,Beclin1,P62,TNF-α,and IL-1β were evaluated by Western blotting.3 Immunofluorescence method was used to observed the cellular localization of LC3.4 Wet/dry method was used to measure brain water content.5 We trained another20 rats to swim before morris water maze testing,and at 7,8,9,10 days after TBI.It is the statistically significant that the value of P was less than 0.05.Results 1 H﹠E staining: Sham group: the histomorphology of brain tissue was normal,number of neurons cells was much,and no obvious pathological changes were found.TBI group: there was obvious tissue edema and loose arranged,neurons swelling,vasodilation,reduced number of neuron,nucleolus shrinkage and hyperchromatic significantly and neuronal degeneration and necrosis in hippocampal area.RV group,the tissue was slightly edema and arranged in good order compared with TBI.And there were more complete structures and more number of neurons in hippocampal area in RV group,and nucleolus shrinkage was improved in hippocampus(P<0.05).2 Expression of LC3 II by western blot: Sham group: the expression of LC3 II protein was weak and there were no changes in each point.TBI group: the expression of LC3 II protein began to increase significantly at 12 h with peaking at 24 h after TBI,and still higher than the basic level till to 48 h in TBI group(P<0.05).RV group: compared with TBI group,the expression of LC3 II protein was lower at corresponding time points(P<0.05).3Expression of Beclin1 by western blot: Sham group: the expression of Beclin1 protein was weak and there were no changes in each point.TBI group: the expression of Beclin1 protein began to increase significantly at 12 h with peaking at 24 h after TBI,and still higher than the basic level till to 48 h in TBI group(P<0.05).RV group: compared with TBI group,the expression of Beclin1 protein was lower at corresponding time points (P<0.05).4 Expression of P62 by western blot: Sham group: the expression of P62 protein was strong and there were no changes in each point.TBI group: the expression of P62 protein began to decrease significantly at 12 h with peaking at 24 h after TBI,and still lower than the basic level till to 48 h in TBI group(P<0.05).RV group: compared with TBI group,the expression of P62 protein was higher at corresponding time points(P<0.05).5 Expression of TNF-α by western blot: Sham group: the expression of TNF-αprotein was weak and there were no changes in each point.TBI group: the expression of TNF-α protein began to increase significantly at 12 h with peaking at 24 h after TBI,and still higher than the basic level till to 48 h in TBI group(P<0.05).RV group: compared with TBI group,the expression of TNF-α protein was lower at corresponding time points6 Expression of IL-1β by western blot: Sham group: the expression of IL-1β protein was weak and there were no changes in each point.TBI group: the expression of IL-1βprotein began to increase significantly at 12 h with peaking at 24 h after TBI,and still higher than the basic level till to 48 h in TBI group(P<0.05).RV group: compared with TBI group,the expression of IL-1β protein was lower at corresponding time points.7Result of LC3 and Neu N by immunofluorescence: We marked LC3 in red fluorescent in cytoplasm,the specific marker of neuron,Neu N,in green fluorescent.And we found that red(LC3)and green(Neu N)were merged together at 24 h following TBI in the injured side of hippocampus.8 Brain water content measurements: Sham group: there was no difference in each point on brain tissue water content.TBI group: the brain water content was significantly increased compared with sham group(P<0.05).RV group: the brain water content in RV group was less than TBI group(P<0.05).9 Results of morris water maze test: Morris water maze test was performed at 7-10 days following TBI.In TBI groups,the average latency in searching safety island was significantly increase compared with the sham group(P<0.05).In RV group,search moving average latency and tracks was improved significantly at 7-10 days after TBI than TBI group(P<0.05).Conclusions ECCI method has been applied successfully to establish the rat model of focal TBI.RV could affect the expression of LC3,Beclin1,P62,TNF-α,and IL-1β in hippocampal area after TBI in rats,thereby reducing neurons autophagy and inflammatory.Treatment with RV which can not only alleviate brain water content but also ameliorate the ability of learning and memory play a neuroprotective effect.