目的 觀察淫羊藿苷對5/6腎切除大鼠腎間質肌成纖維細胞增殖的影響，并探討其作用機制。方法 將大鼠分為假手術組、模型組及淫羊藿苷高、低劑量（100、50 mg·kg^-1）組。假手術組僅分離腎包膜，模型組及淫羊藿苷高、低劑量組進行5/6腎切術，每組7只。術后第3周開始給藥，每日1次。14周末留取大鼠血清，檢測肌酐（Scr）、尿素氮（BUN）；取部分腎臟，蘇木精-伊紅（HE）染色法常規(guī)病理檢查觀察組織學改變；天狼星紅染色檢測腎間質纖維化；免疫組織化學法檢測腎臟組織α-平滑肌肌動蛋白（α-SM?。?、轉化生長因子-β1（TGF-β1）、大鼠磷酸化信號轉導分子2/3（p-SMAD2/3）、DNA甲基轉移酶3A（Dnmt3a）的表達，另部分腎臟凍存，Western blotting檢測α-SMA、TGF-β1、和Dnmt3a蛋白表達。結果 HE染色及天狼星紅染色結果顯示模型組大鼠腎小管擴張或萎縮，有大量纖維組織增生及膠原沉積，并見散在炎癥細胞浸潤。免疫組化結果顯示模型組肌成纖維細胞標記物α-SMA表達明顯升高，促纖維化因子TGF-β1及其下游分子p-Smad2/3表達明顯增加；DNA甲基轉移酶Dnmt3a表達明顯升高。淫羊藿苷處理可以減輕腎臟病理損傷，抑制肌成纖維細胞異常增殖，改善腎間質纖維化，下調α-SMA、TGF-β1、p-Smad2/3和Dnmt3a表達。除淫羊藿苷高劑量組抑制Dnmt3a表達的效應強于淫羊藿苷低劑量組外，其余指標淫羊藿苷高劑量組和低劑量組效應差異不明顯。結論 淫羊藿苷在5/6腎切除誘導的慢性腎病（CKD）大鼠中表現(xiàn)出抗纖維化作用，其機制可能是通過調控TGF-β1誘導的DNA高甲基化抑制肌成纖維細胞增殖，改善腎間質纖維化。

Objective To observe the effect of icariin on proliferation of renal interstitial myofibroblasts in 5/6 nephrectomized rats and explore its mechanism. Methods The rats were divided into sham operation group, model group, icariin high-dose group and icariin low-dose group. In the sham operation group, only the renal envelope was separated without nephrectomy, and the model group and icariin group underwent 5/6 nephrectomy, with seven rats in each group. Icariin was given 50 mg·kg^-1 in low-dose icariin group and 100 mg·kg^-1 in high-dose icariin group, once a day. The serum of rats was collected at the end of the 14th week to detect creatinine (Scr) and urea nitrogen (BUN). Part of the kidney was taken and histological changes were observed by routine pathological examination. Sirian red staining was used to detect renal interstitial fibrosis. The expressions of α-smooth muscle actin (α-SMΑ), transforming growth factor-β1 (TGF-β1), phospho-small mothers against decapentaplegic homolog 2/3 (p-SMAD2/3) and DNA methyltransferase 3A (Dnmt3a) in kidney tissues were detected by immunohistochemistry. The expressions of α -SMA, TGF- β1 and Dnmt3a in other kidney tissues were detected by Western blotting. Results HE and Sirius red staining showed that renal tubules in the model group were dilated or atrophied, with a large amount of fibrous tissue hyperplasia and collagen deposition, and scattered inflammatory cell infiltration. Immunohistochemical results showed that the expression of α -SMA, TGF- β1 and its downstream molecule p-Smad2/3 were significantly increased in the model group. The expression of DNA methyltransferase Dnmt 3a was significantly increased. Icariin treatment can alleviate renal pathological injury, inhibit abnormal proliferation of myofibroblasts, improve renal interstitial fibrosis, and down-regulate the expression of α-SMA, TGF-β1, p-Smad2/3 and Dnmt3a. The inhibitory effect of icariin high-dose group on Dnmt 3a expression was stronger than that of icariin low-dose group, but there was no significant difference in the effect of other indicators between icariin high-dose group and low-dose group. Conclusion Icariin shows an antifibrotic effect in 5/6 nephrectomy induced CKD rats, the mechanism may be through regulating TGF-β1- induced DNA hypermethylation to inhibit myofibroblasts proliferation and attenuate renal interstitial fibrosis.

R572;R363

天津市衛(wèi)生健康科技項目（TJWJ2022MS050）