血必净对百草枯中毒所致肺纤维化过程中Smads信号蛋白的影响

The effects of Xuebijing on Smads signaling protein expression in paraquat-induced pulmonary fibrosis

目的:观察血必净对百草枯(PQ)所致肺纤维化过程中Smads蛋白的影响,初探血必净对肺纤维化的干预机制。方法:将SPF级C57BL/6J小鼠分为1正常对照组:予以腹腔注射等量生理盐水;2模型组(PQ组):腹腔一次注射18mg/kg剂量PQ;3血必净干预组:腹腔一次注射18mg/kg剂量PQ;0.5h后小鼠尾静脉注射50ml/kg血必净注射液(以后1次/d)。分别于第3、7、14天处死小鼠采集标本进行检测。苏木精-伊红染色观察肺组织病理改变;Western blot检测肺组织Smad2/3、p-smad2/3、Smad7蛋白的表达;RT-PCR检测Smad7mRNA表达。结果:1正常组小鼠肺组织苏木精-伊红染色肺泡结构正常,肺泡及间质区域无充血或炎性细胞浸润;模型组肺泡闭塞,肺泡腔面积减少,存在片状实变区域;血必净干预3d组肺组织弥漫性出血减少,有少量胶原沉积在细支气管周围;血必净干预7d组肺组织充血及出血较严重,部分闭塞,肺泡壁增厚明显,可见纤维细胞增殖、胶原沉积于血管及支气管周围;血必净干预14d组肺结构破坏明显,形成纤维块或纤维束,说明血必净早期干预对肺组织改善的效果明显;2模型组Samds信号蛋白p-smad2/3、Smad7表达上调,血必净干预后可不同程度地下调p-smad2/3高表达,增强Samd7的表达,血必净干预3d组作用较为显著。结论:成功构建百草枯所致小鼠肺纤维化模型,血必净可作用于Smads信号转导通路正、负反馈环路中的Smad2/3、Smad7关键信号蛋白,早期部分阻抑百草枯所致肺纤维化的进展。

Objective：To observe the effects of Xuebijing on the expression of Smads signaling protein in paraquat-induced pulmonary fibrosis and investigate the treatment of Xuebijing in pulmonary fibrosis.Method：We divided SPF grade of C57BL/6Jmouse into five groups：The control group：intraperitoneal injection of saline solution;Model group：intraperitoneal injection of PQ 18mg/kg;Xuebijing Intervention group：after intraperitoneal injection of PQ 18mg/kg for 30 min,the tail intravenous injection of Xuebijing 50 mg/kg（Once a day in the future）.After 3,7,14 days,mice were sacrificed and lung tissues were collected.Using HE staining to observe pathological changes in the lung tissue.Western blot was used to detect the expression of Smad2/3,p-smad2/3and Smad7.Smad7 mRNA expression was detected by RT-PCR.Result：1Lung tissue sections from control rats showed no evidence of inflammation,edema or epithelial damage.As expected,lung tissue sections from PQ mice showed extensive cellular thickening of interalveolar septa,interstitial edema,increased interstitial cells with a fibroblastic appearance,and alveolar space area reduction.After treatment with Xuebijing for 3days,we found that Xuebijing could attenuate diffuse hemorrhage;injury areas and collagen deposition were dramatically reduced.In Xuebijing intervention 7days group and 14 days group,still showed extensive cellular thickening,increased interstitial fibrosis and excessive collagen deposition.The results of HE staining indicated that Xuebijing could attenuate lung injury induced by paraquat in the early intervention phase.2The expressions of p-smad2/3 were up-regulated in PQ group,but Xuebijing induced the expressions of p-smad2/3decreased and promoted the expression of Samd7.Xuebijing intervention for 3days group significantly affected the expressions of p-smad2/3and samd7.Conclusion：Xuebijing could affect the exressions of key signaling protein Smad2/3,Smad7 in the positive and negative feedback loops of Smads signal transduction pathway,and it could inhibit paraquat-induced pulmonary fibrogenesis in early phase.