Investigation of the apoptotic mechanism in hippocampal and retinal neurons of db/db mice induced by Dihuangyinzi decoction

In the present study,we utilized db/db mice to investigate the mechanisms of apoptosis in brain and retinal neurons.A total of 30 male db/db mice aged 8–9 weeks were randomly assigned to the model group,Dihuangyinzi decoction(DHYZ)group(30.03 g/kg),and metformin(MET)group(0.58 g/kg),with 10 mice in each group.The control group comprised 10 db/m mice of the same background and age.Paired-associate learning(PAL)tests were conducted to evaluate the learning and memory functions of the mice.Histological assessments,including Hematoxylin-Eosin(H&E)and Nissl staining,were employed to observe changes in nerve cells in the hippocampus and retina.Immunohistochemistry and real-time fluorescence quantitative PCR were employed to detect the positive expression of anti-apoptotic factor Bcl-2 and pro-apoptotic factor Bax at the protein and mRNA levels in the hippocampus and retina.Western blotting analysis was adopted to assess protein expression levels of JNK,p-JNK,p38 MAPK,and p-p38 MAPK.Results revealed a significant decline in the correct rate of PAL test results in the model group(P<0.001),accompanied by increased reaction and delay times(P<0.001)and higher blood glucose levels(P<0.001).H&E and Nissl staining indicated a reduction in the number of nerve cells in the CA1 area of the hippocampus in the model group,with scattered arrangement and decreased Nissl corpuscles.Positive expression and mRNA expression of Bax in the hippocampus and retina increased significantly(P<0.001),while positive expression and mRNA expression of Bcl-2 decreased(P<0.001).Protein expression levels of p-JNK/JNK and p-p38 MAPK/p38 MAPK showed a significant increase(P<0.001).The DHYZ and MET groups exhibited enhanced accuracy in PAL experiments(P<0.05),decreased reaction time and delay time(P<0.05),and reduced blood glucose levels(P<0.05).The number of neurons in the CA1 region of the hippocampus increased,morphological structure improved,and the arrangement of the hippocampal structure became more orderly.Additionally,no obvious vacuolization was observed in the neuronal cell layer.The number of Nissl bodies increased,and the layers of the retina were closely arranged,with an increase in the number of Nissl bodies.Positive expressions of Bax in the hippocampus and retina,both at the protein and mRNA levels,decreased significantly(P<0.001),while positive expressions of Bcl-2 and its mRNA increased(P<0.01,P<0.001).Furthermore,the protein expressions of p-JNK/JNK and p-p38 MAPK/p38 MAPK decreased significantly(P<0.01).This study suggested that DHYZ decoction could inhibit the JNK/p38 MAPK signaling pathway,thereby increasing the anti-apoptotic factor Bcl-2 and reducing the expression of the pro-apoptotic factor Bax,consequently inhibiting apoptosis in the hippocampal CA1 region and retinal neurons of db/db mice.

基于网络药理学及实验验证探究当归补血汤治疗糖尿病性视网膜病变的作用机制

本研究使用网络药理学、分子对接结合实验验证探究当归补血汤在糖尿病视网膜病变(Diabetic retinopathy,DR)中的作用机制。从TCMSP、TCMID、Swiss Target Prediction数据库筛选当归补血汤活性成分及其靶点,通过Gene Cards、Dis Ge NET收集DR靶点,利用Venny 2.1获得二者交集靶点。使用Cytoscape构建“疾病-药物-成分-靶点”、蛋白互作(PPI)网络;DAVID数据库对关键靶点进行基因本体论(GO)和京都基因与基因组百科全书(KEGG)富集分析;Auto Dock Vina对主要活性成分与关键靶点进行分子对接验证。最后,通过动物实验验证网络药理学结果。收集到当归补血汤与DR共同靶点84个。GO分析显示220个条目;KEGG富集分析得到113条信号通路。分子对接结果显示关键靶点与槲皮素、豆甾醇等有效成分均具有较好的对接活性。动物实验表明当归补血汤可改善DR大鼠视网膜组织形态,降低血糖,增加胰岛素分泌,降低DR大鼠视网膜组织VEGF、TNF-α蛋白表达水平、提高PI3K、Akt1表达水平(P<0.05,P<0.01)。当归补血汤治疗DR具有多活性成分、多靶点、多通路的特点,可通过调节TNF-α、VEGFA、PI3K、AKT等核心靶点,影响PI3K/AKT、TNF等信号通路发挥对DR的治疗作用。