| Objective:The study was aimed to investigate the effects of Shenqi Yizhi Granule on the learning and memory abilities,the hippocampus pathological changes,the brain astrocytes abnormality and JAK2/STAT3 signal pathway in A?1-42-42 bilateral hippocampal injection AD rats.Investigate the molecular mechanisms of Shenqi Yizhi Granule?SYG?through regulating brain astrocytes abnormality via JAK2/STAT3signaling pathway in order to provide a scientific basis for clinical application of Shenqi Yizhi Granule.Methods:1.Model construction and group interventionThe AD rat model was established by A?1-42-42 bilateral hippocampal injection,and the rats with cognitive impairment were selected for follow-up study after directional navigation test.After randomly grouping,the model rats were given the model Shenqi Yizhi Granule for continuous 60 days.2.Effects of Shenqi Yizhi Granule on learning and memory function in A?1-42 bilateral hippocampal injection AD ratsThe effect of Shenqi Yizhi Granule on learning and memory function in A?1-42 bilateral hippocampal injection AD rats was investigated by Morris water maze test,and the effect of Shenqi Yizhi Granule on the pathological morphology of hippocampus in A?1-42-42 bilateral hippocampal injection AD rats was investigated by using HE staining method.3.Effects of Shenqi Yizhi Granule on brain astrocytes in A?1-42-42 bilateral hippocampal injection AD ratsThe effects of Shenqi Yizhi Granule on the number of astrocyte and cell protuberance in A?1-42-42 bilateral hippocampal injection AD rats were examined by immunohistochemistry.The effects of Shenqi Yizhi Granule on the glutamic acid concentration and glutamine synthetase activity in the brain tissue in A?1-42-42 bilateral hippocampal injection AD rats were examined by chemical assay kit.4.Study on the mechanisms of Shenqi Yizhi Granule through brain JAK2/STAT3 signaling pathway in A?1-42-42 bilateral hippocampal injection AD ratsThe Elisa kit was used to detect the expression of IL-6 in the brain in A?1-42 bilateral hippocampal injection AD rats.The qRT-PCR method was used to detect the expression of JAK2 mRNA and STAT3 mRNA in A?1-42-42 bilateral hippocampal injection AD rats.Western blot method was used to detect the phosphorylation level of JAK2 an STAT3 in A?1-42-42 bilateral hippocampal injection AD rats.Results:1.Effects of Shenqi Yizhi Granule on learning and memory abilities in A?1-42bilateral hippocampal injection AD ratsThe experimental results showed that the escape latency of the model group was significantly increased?P<0.05?compared with the sham group,and the escape latency of the Shenqi Yizi granule groups was significantly lower than that of the model group?P<0.05?.The results of space exploration experiment showed that compared with the sham group,the times of crossing platform of the model group decreased significantly?P<0.05?,the time percentage of the model group in the platform quadrant significantly decreased?P<0.01?and the time percentage of the model group in the diagonal platform quadrant significantly increased?P<0.01?.Compared with the model group,the times of cross platform in the Shenqi Yizi granule groups increased significantly,the time percentage in the platform quadrant increased significantly?P<0.05?and the time percentage in the diagonal platform quadrant decreased significantly?P<0.05?.2.Effect of Shenqi Yizhi Granule on the pathomorphology of hippocampus in A?1-42-42 bilateral hippocampal injection AD ratsCompared with the sham group,the cells in the CA3 area of the hippocampus of the model group were obviously disturbed?P<0.05?,and the neurons showed obvious necrosis,vacuolization and glial cell proliferation?P<0.01?.Compared with the model group,the above pathological phenomena in the hippocampus CA3 area of Shenqi Yizhi Granule groups were all improved?P<0.05?.3.Effects of Shenqi Yizhi Granule on brain astrocytes abnormality in A?1-42bilateral hippocampal injection AD ratsCompared with the sham group,the astrocytes in the hippocampal CA3 region of the model group were obviously hyperplastic,and the specific marker GFAP expression increased significantly?P<0.01?,and the cell process increased significantly and became longer?P<0.01?.Compared with the model group,the expression of astrocytes in the hippocampus CA3 region of Shenqi Yizhi Granule groups was significantly decreased?P<0.05?,and the cell process was significantly shortened?P<0.01?.Compared with the sham group,the glutamate concentration in the brain of the model group increased significantly?P<0.01?,and the activity of glutamine synthetase decreased,but there was no significant difference.Compared with the model group,the concentration of glutamate concentration in the rats of Shenqi Yizi Granule groups decreased significantly?P<0.01?,the activity of glutamine synthetase increased,and the difference between the middle dosage group and the low dose group of Shenqi Yizhi Granule were statistically significant?P<0.05?.4.Effects of Shenqi Yizhi Granule on JAK2/STAT3 signaling pathway in A?1-42bilateral hippocampal injection AD ratsCompared with sham group,the expression of IL-6 in brain tissue of model group increased slightly,but the difference was not statistically significant.Compared with the model group,the expression of IL-6 in brain tissue of Shenqi Yizhi Granule groups was decreased,but the difference was not statistically significant.At the gene level,compared with the sham group,the expression of JAK2 mRNA and STAT3 mRNA in hippocampus of model group were increased significantly?P<0.01?.The expression of JAK2 mRNA and STAT3 mRNA in hippocampus of rats in Shenqi Yizhi Granule groups was significantly reduced compared with the model group?P<0.01?.At the protein level,compared with the sham group,the level of phosphorylation of JAK2 and STAT3 protein was significantly increased,and the difference was statistically significant?P<0.05?.The phosphorylation level of JAK2 and STAT3protein in the hippocampus of Shenqi Yizhi Granule groups decreased significantly compared with the model group,and the difference was statistically significant?P<0.05?.Conclusion:Shenqi Yizhi Granule can improve the learning and memory function and hippocampal pathological changes in A?1-42-42 bilateral hippocampal injection AD rats,inhibit the abnormal astrocyte and inhibit the expression of genes and proteins related to the JAK2/STAT3 signaling pathway,suggesting that the reversal of astrocyte abnormalities by antagonizing the JAK2/STAT3 signaling pathway may be the mechanism of Shenqi Yizhi Granule in treating Alzheimer's disease. |
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