天麻钩藤饮通过调节TNF-α/STAT3/α1ACT信号通路抑制A1型星型胶质细胞激活减轻血管性痴呆模型大鼠神经元损伤作用机制OA

Objective:To investigate the effects of Tianma Goutengyin on the tumor necrosis factor-α(TNF-α)/signal transducer and activator of transcription 3(STAT3)/α1-antichymotrypsin C-terminal tail fragment(α1ACT)signaling pathway and A1-type astrocytes in a rat model of vascular dementia.Methods:Seventy-two male Sprague-Dawley rats were randomly divided into six groups(n=12 per group):Sham-operated group,model group,Tianma Goutengyin high-,medium-,and low-dose groups(5.13,10.26,and 20.52 g·kg-1),and a nimodipine group(8.1 mg·kg-1).The vascular dementia model was established by permanent bilateral common carotid artery occlusion,followed by 4 weeks of intervention.Learning and memory ability were evaluated using the novel object recognition test,and behavioral performance was assessed using the forced swimming test.Levels of interleukin-6(IL-6)and C-C motif chemokine ligand 2(CCL2)in hippocampal tissue were measured by enzyme-linked immunosorbent assay(ELISA).Hippocampal neuronal morphology was observed by Nissl staining,and apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL).Immunohistochemistry was used to detect positive expression of brain-derived neurotrophic factor(BDNF),glial fibrillary acidic protein(GFAP),and myelin basic protein(MBP).Western blot analysis was performed to measure the protein expression levels of TNF-α,TNF receptor 1(TNFR1),phosphorylated STAT3(p-STAT3),α1 ACT,IL-6,complement component 3(C3),BDNF,S1 00 calcium-binding protein A10(S100A10),and GFAP in hippocampal tissue.Results:Compared with the sham-operated group,the model group showed a significantly reduced relative recognition index in the novel object recognition test(P＜0.01),prolonged immobility time and increased immobility frequency in the forced swimming test(P＜0.01).Hippocampal IL-6 and CCL2 levels were significantly increased(P＜0.01).Nissl staining revealed a marked reduction in neuronal number and loss of Nissl bodies(P＜0.01).MBP-positive expression was significantly decreased(P＜0.01),apoptosis was significantly increased(P＜0.01),BDNF-positive expression was significantly reduced(P＜0.05),and GFAP-positive expression was significantly increased(P＜0.01).In addition,the protein expression levels of TNF-α,TNFR1,p-STAT3,α1ACT,IL-6,and C3 were significantly elevated(P＜0.01),while BDNF and S100A10 expression levels were significantly decreased(P＜0.01).Compared with the model group,all Tianma Gouteng yin dose groups exhibited a significant increase in the relative recognition index(P＜0.05),shortened immobility time and reduced immobility frequency(P＜0.05,P＜0.01).IL-6 and CCL2 levels were significantly decreased(P＜0.01),neuronal number was significantly increased(P＜0.05,P＜0.01),and MBP-positive expression was significantly enhanced(P＜0.01).Apoptosis was significantly reduced(P＜0.01),BDNF-positive expression was significantly increased(P＜0.05),and GFAP-positive expression was significantly decreased(P＜0.01).Moreover,the protein expression levels of TNF-α,TNFR1,p-STAT3,α1ACT,IL-6,and C3 were significantly decreased(P＜0.01),while BDNF and S10OA10 protein expression levels were significantly increased(P＜0.01).Conclusion:Tianma Goutengyin may inhibit A1-type astrocyte activation in rats with vascular dementia through the TNF-α/STAT3/α1ACT signaling pathway,thereby reducing neuronal apoptosis and improving learning and memory function.