黄芩苷对单侧输尿管梗阻肾间质纤维化大鼠模型的治疗作用及机制研究

Therapeutic effect of baicalin in treatment of renal interstitial fibrosis in rats with unliateral ureteral obstruction and related mechanisms

目的探讨不同剂量黄芩苷在不同时间对单侧输尿管梗阻(UUO)肾间质纤维化模型大鼠的治疗作用及机制。方法将64只Sprague Dawley大鼠随机分为假手术组、模型组、黄芩苷小剂量治疗组(小剂量组)和黄芩苷大剂量治疗组(大剂量组),每组再随机分为7 d组和14 d组,每组8只。采用左侧输尿管结扎的方法制作大鼠UUO模型。苏木精-伊红染色观察各组肾脏病理改变;ELISA法检测各组血清TGF-β1、Notch1和Jagged1的含量;免疫组化法检测各组TGF-β1和Notch1的表达。Pearson法对各检测指标间行相关分析。结果苏木精-伊红染色结果显示7 d和14 d模型组肾间质炎性细胞浸润、水肿,肾小管扩张、结构紊乱,肾小管上皮细胞变性、坏死,肾小球结构基本正常;大、小剂量组病变程度均较模型组减轻。7 d和14 d模型组大鼠血清TGF-β1含量及肾组织TGF-β1阳性细胞数均较假手术组明显增高(P<0.05);7 d和14 d大、小剂量组血清TGF-β1含量及肾组织TGF-β1阳性细胞数均较同时间点模型组下降(P<0.05)。7 d和14 d各组血清Notch1含量差异无统计学意义(P>0.05);但模型组肾组织Notch1阳性细胞数较假手术组增加,而大、小剂量组均较同时间点模型组下降(P<0.05)。7 d和14 d各组血清Jagged1含量差异无统计学意义(P>0.05)。大鼠血清TGF-β1与Notch1含量变化呈正相关(r=0.650,P<0.01);血清Notch1与Jagged1含量变化呈正相关(r=0.727,P<0.01);大鼠肾组织TGF-β1与Notch1的阳性细胞数亦呈正相关(r=0.743,P<0.01)。结论黄芩苷治疗可减轻UUO大鼠肾间质纤维化,其机制可能与通过抑制Notch1信号通路从而抑制TGF-β1的表达有关。

Objective To investigate the therapeutic effect of baicalin at different doses administered for different periods of time in the treatment of renal interstitial fibrosis in rats with unliateral ureteral obstruction（UUO） and related mechanisms. Methods Sixty-four Sprague-Dawley rats were randomly divided into sham-operation, model, low-dose baicalin, and high-dose baicalin groups, and each group was further randomly divided into 7-day and 14-day groups（n=8 each）. Left ureteral ligation was used to establish the rat model of UUO. Hematoxylin and eosin staining was used to observe the pathological changes in the kidney. ELISA was used to measure the serum levels of transforming growth factor-β1（TGF-β1）, Notch1, and Jagged1. Immunohistochemistry was used to measure the expression of TGF-β1 and Notch1. The Pearson correlation analysis was used for correlation analysis. Results Hematoxylin and eosin staining showed inflammatory cell infiltration and edema in renal interstitium, tubular dilation and structure disorder, degeneration and necrosis of renal tubular epithelial cells, and a basically normal structure of the glomeruli on days 7 and 14 in the model group, and these lesions were alleviated in the low- and high-dose baicalin groups. Compared withthe sham-operation group, the model group had a significantly higher serum level of TGF-β1 and a significantly higher number of TGF-β1-positive cells in renal tissues on days 7 and 14（P〈0.05）. Compared with the model group at the same time points, the high- and low-dose baicalin groups had a significantly lower serum level of TGF-β1 and a significantly lower number of TGF-β1-positive cells in renal tissues on days 7 and 14（P〈0.05）. The serum level of Jagged1 showed no significant differences between any two groups on days 7 and 14（P〉0.05）. The serum level of TGF-β1 was positively correlated with that of Notch1（r=0.650, P〈0.01）, and the serum level of Notch1 was positively correlated with that of Jagged1（r=0.727, P〈0.01）. TGF-β1 level in renal tissues was also positively correlated with the number of Notch1-positive cells（r=0.743, P〈0.01）. Conclusions Baicalin can alleviate renal interstitial fibrosis in UUO rats, probably by inhibiting Notch1 signaling pathway and the expression of TGF-β1.