小鼠AAN激活Wnt/β-Catenin信号通路及诱导肾脏纤维化的观察性研究

Observational Study of Wnt/β-Catenin Signaling Pathway Activation and Induction of Renal Fibrosis in Mice by AAN

目的:观察慢性AAN的肾损伤病理改变以及β-catenin和α-SMA蛋白的表达改变,探索Wnt/β-catenin信号通路与AAN纤维化之间的关系。方法:雄性KM小鼠随机分为3组,对照组灌胃给药0.4% CMC 0.2 mL/kg/2d,AAI组小鼠灌胃给药AAI 5 mg/kg/2d,青木香组灌胃给药青木香悬浊液5 mg/kg/2d。分别于4周和8周处死,HE染色观察肾组织病理变化,Masson染色观察纤维化情况,免疫组化染色观察β-catenin和α-SMA两种蛋白的组织定位和蛋白表达量。结果:AAI和青木香对小鼠的肾脏有毒性作用,小鼠长期暴露于AAI和青木香后肾小管上皮细胞出现水肿、坏死和脱落。β-catenin免疫组化结果显示,与对照组相比,肾小管上皮细胞中的β-catenin表达增高,免疫组化平均光密度值明显增高(P < 0.05)。Masson染色结果显示小鼠暴露于AAI后肾脏出现纤维化,与对照组相比,胶原纤维溶剂分数明显增加(P < 0.05)。α-SMA的免疫组化结果显示,与对照组相比,α-SMA的表达也明显升高,免疫组化平均光密度值显著增加(P < 0.05)。结论:慢性AAN主要损伤肾脏近曲小管上皮细胞,表现为细胞水肿、坏死和脱落;β-catenin的表达增加,胶原纤维和α-SMA的表达增多。AAN肾脏纤维化的发生可能与Wnt/β-catenin信号通路有关。

Objective: The pathological changes of kidney injury and the expression of β-catenin and α-SMA protein in mice poisoned with AAN were observed to explore the relationship between Wnt/β-catenin signaling pathway and AAN fibrosis. Methods: Male KM mice were randomly divided into three groups: the control group was given 0.4% CMC 0.2 mL/kg/2d by gavage, the AAI group was given AAI 5 mg/kg/2d by gavage, and the Aristolochia debilis Sieb. et Zucc group was given Aristolochia debilis Sieb. et Zucc suspension 5 mg/kg/2d by gavage. Mice were executed at 4 and 8 weeks, respectively. HE staining was used to observe the histopathological changes of kidney, Mas-son staining was used to observe the fibrosis, and immunohistochemical staining was used to ob-serve the tissue localization and protein expression of both β-catenin and α-SMA proteins. Results: AAI and cyanophyllum had toxic effects on the kidneys of mice. Mice showed edema, necrosis and detachment of renal tubular epithelial cells after long-term exposure to AAI and cyanophyllum. The results of β-catenin immunohistochemistry showed an increased expression of β-catenin in renal tubular epithelial cells and significantly higher immunohistochemical mean optical density values compared with the control group (P < 0.05). Masson staining results showed increased renal fibrosis in mice exposed to AAI, with a significant increase in the collagen fibril solvent fraction compared to controls (P < 0.05). The immunohistochemical results of α-SMA showed that the expression of α-SMA was also significantly higher compared with the control group, and the mean optical density value of immunohistochemistry was significantly increased (P < 0.05). Conclusion: Chronic AAN mainly damages the epithelial cells of the proximal tubule of the kidney, manifesting as cell edema, necrosis and detachment. The expression of β-catenin protein was increased, as was the number of collagen fibers and the expression of α-SMA protein.