阻断Notch信号通路延缓尿酸诱导大鼠肾脏损伤的机制

    Blocking Notch signal pathway delayed uric acid-induced renal injury in rats

    • 摘要: 目的 探讨γ-分泌酶抑制剂DAPT对尿酸诱导大鼠肾脏损伤中的作用及其机制。方法 21只雄性SD大鼠随机分为正常对照组(control,n=7)、高尿酸模型组(OA+UA,n=7)、DAPT治疗组(OA+UA+DAPT,n=7)。OA+UA组予2%氧嗪酸2.5mL/100g灌胃,3次/d,同时予0.1mmol/L尿酸饮水,OA+UA+DAPT组在造模的同时每天予γ-分泌酶抑制剂DAPT500μg/100g腹腔注射。对照组给予正常食物,腹腔注射等量生理盐水,模型建立8周时处死大鼠。用HE、Masson染色分析肾脏病理形态学变化,qRT-PCR、Western blot检测Notch信号通路Notch1/Jagged1/Hes1、转化生长因子-β(transforming growth factor-β,TGF-β)和a平滑肌肌动蛋白(a-smooth muscle actin,a-SMA)的mRNA和蛋白表达水平,并用免疫组化观察上述指标在大鼠肾脏的定位。结果 与对照组相比,OA+UA组HE染色发现部分肾小管上皮细胞肿胀、脂肪变性、部分肾小管上皮细胞脱落,管腔扩张变形,部分肾小管萎缩,可见褐色针状放射状尿酸盐结晶。Masson染色肾小管间质可见明显波浪状的胶原纤维呈亮绿色沉积。Notch1/Jagged1/Hes1、TGF-β1和α-SMA表达水平明显增加。DAPT治疗后大鼠肾脏病理损伤较模型组的改变减轻,肾脏间质纤维化减少,Notch1/Jagged1/Hes1表达水平下调,同时TGF-β1和α-SMA表达减少。结论 Notch信号通路抑制剂DAPT可以延缓高尿酸引起的大鼠慢性肾病损伤。

       

      Abstract: Objective To investigate the effect and mechanism of γ-secretase inhibitor DAPT on uric acid-induced renal injury in rats. Methods Twenty-one male SD rats were randomly divided into normal control group(control, n=7), hyperuricemia model group(OA+UA, n=7), and DAPT treatment group(OA+UA+DAPT, n=7). The OA+UA group was given 2.5 mL/100g of 2% oxazine by gavage, 3 times a day, and 0.1 mmol/L uric acid was given to drink water at the same time. OA+ UA+DAPT was given Notch signaling pathway specific inhibitor every day while modeling. γ-secretase inhibitor DAPT 500 μg/100g intraperitoneal injection. The control group was given normal food and intraperitoneally injected with the same volume of normal saline. Seven rats in each group were sacrificed at 8 weeks after model establishment. The histopathological changes of the kidney were determined by hematoxylin-eosin staining(HE)and Masson staining. qRT-PCR and Western blot were used to detect the level of Notch signaling pathway receptor Notch1, ligand Jagged1 and hair division-related enhancer 1 (Hes1), TGF-β1 and α-SMA. The location of the above indicators in the kidneys of rats was observed by immunohistochemistry. Results Compared with the control group, HE staining in the OA+UA group showed that some renal tubular epithelial cells were swollen and shed. The lumens were expanded and deformed. Part of renal tubules were atrophied and widening. With inflammatory infiltration, the brown needle-like radial urate crystals can be seen in the renal interstitium at 8 weeks. Masson staining showed obvious wavy collagen fibers in the tubulointerstitium, which were bright green staining. While the morphological changes were milder in OA+UA+DAPT group. Compared with the control group, the expression levels of Notch1/Jagged1/Hes1, TGF-β1 and α-SMA were significantly increased in the OA+ UA group. Compared with the model group, the damage of renal in the rats after DAPT treatment were significantly alleviated. The renal interstitial fibrosis was reduced, As same as the expression levels of Notch1/Jagged1/Hes1, the expression of TGF-β1 and α -SMA decreased in OA+UA+DAPT group. Conclusions The Notch signaling pathway is activated during uric acid-induced renal injury in rats. DAPT, the Notch signaling pathway inhibitor, would delay the renal injury in rats induced by uric acid.

       

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