黄芩苷调节HIF-1α/VEGF信号通路对腹膜透析大鼠腹膜纤维化和血管生成的影响

Effects of Baicalin on Peritoneal Fibrosis and Angiogenesis in Peritoneal Dialysis Rats by Regulating HIF-1α/VEGF Signaling Pathway

目的:探究黄芩苷调节低氧诱导因子1α/血管内皮生长因子(HIF-1α/VEGF)信号通路对腹膜透析大鼠腹膜纤维化和血管生成的影响。方法:将SD大鼠分为空白组、模型组、黄芩苷低剂量组(25 mg/kg)、黄芩苷高剂量组(100 mg/kg)、HIF-1α激活剂FG-4592组(10 mg/kg)、黄芩苷高剂量+FG-4592组(100 mg/kg黄芩苷+10 mg/kg FG-4592),每组10只。除空白组外,其余各组采用4.25%葡萄糖腹膜透析溶液腹腔注射,建立腹膜透析大鼠模型,各组大鼠建模同时给予相应药物处理,每天1次,共给予30 d,空白组、模型组给予等体积生理盐水;4 h腹膜平衡试验评估腹膜功能;HE和Masson染色观察大鼠腹膜组织病理损伤、厚度及纤维化程度;腹膜血管新生形态观察;免疫组化检测大鼠腹膜组织中α-平滑肌肌动蛋白(α-SMA)、VEGF和上皮钙黏素(E-cadherin)表达;实时荧光定量PCR(qRT-PCR)和Western Blot测定大鼠腹膜组织HIF-1α、VEGF表达水平。结果:与空白组相比,模型组大鼠超滤体积、E-cadherin表达水平显著降低,腹膜厚度、葡萄糖转运量、毛细血管密度、α-SMA水平及HIF-1α、VEGF表达显著升高,大鼠腹膜组织有大量炎性细胞浸润且出现蓝染的胶原沉积(P<0.05);与模型组相比,黄芩苷低剂量组、黄芩苷高剂量组大鼠超滤体积、E-cadherin表达水平显著升高,腹膜厚度、葡萄糖转运量、毛细血管密度、α-SMA水平及HIF-1α、VEGF表达显著降低,大鼠腹膜组织病理损伤及纤维化有所改善(P<0.05),FG-4592组对应指标变化趋势与上述相反(P<0.05);FG-4592减弱了高剂量黄芩苷抑制腹膜透析大鼠腹膜纤维化和血管生成的作用。结论:黄芩苷通过抑制HIF-1α/VEGF信号通路抑制腹膜透析大鼠腹膜纤维化和血管生成。

Objective:To explore the effect of Baicalin on peritoneal fibrosis and angiogenesis in peritoneal dialysis rats by regulating hypoxia inducible factor-1α/vascular endothelial growth factor(HIF-1α/VEGF)signaling pathway.Methods:SD rats were grouped into blank group,model group,low-dose Baicalin group(25 mg/kg),high-dose Baicalin group(100 mg/kg),HIF-1αactivator FG-4592 group(10 mg/kg),high-dose Baicalin+FG-4592 group(100 mg/kg Baicalin+10 mg/kg FG-4592),with 10 rats in each group.In addition to the blank group,4.25%glucose peritoneal dialysis solution was intraperitoneally injected into other groups to establish peritoneal dialysis rat models.The rats in each group were given corresponding drug treatment,once a day,for a total of 30 days.The blank group and the model group were given equal volumes of physiological saline.The 4-hour peritoneal balance test was applied to evaluate peritoneal function;HE and Masson staining were applied to observe the pathological damage,thickness,and degree of fibrosis in peritoneal tissue;the morphology of peritoneal angiogenesis was observed;immunohistochemistry was applied to detect the expression ofα-smooth muscle actin(α-SMA),VEGF and epithelial cadherin in peritoneal tissue;real-time fluorescence quantitative-PCR(qRT-PCR)and Western Blot were applied to measure the expression levels of HIF-1αand VEGF in peritoneal tissue.Results:Compared with the blank group,the ultrafiltration volume and the expression level of E-cadherin in the model group were obviously reduced,the peritoneal thickness,glucose transport capacity,capillary density,level ofα-SMA,and expression of HIF-1αand VEGF were obviously increased,there was a large amount of inflammatory cell infiltration and blue stained collagen deposition in the peritoneal tissue of rats(P<0.05);compared with the model group,the ultrafiltration volume and E-cadherin expression level of rats in the low-dose Baicalin group and the high-dose Baicalin group increased obviously,the ultrafiltration volume and the expression level of E-cadherin in the low-dose Baicalin group and the high-dose Baicalin group were obviously increased,the peritoneal thickness,glucose transport capacity,capillary density,level ofα-SMA,and expression of HIF-1αand VEGF were obviously reduced,the pathological damage and fibrosis of rat peritoneal tissue improved(P<0.05),the change trend of corresponding indicators in the FG-4592 group was opposite to the above(P<0.05);FG-4592 attenuated the effect of high-dose Baicalin in inhibiting peritoneal fibrosis and angiogenesis in peritoneal dialysis rats.Conclusion:Baicalin inhibits peritoneal fibrosis and angiogenesis in peritoneal dialysis rats by inhibiting HIF-1α/VEGF signaling pathway.