Meng Lihong, Zhang Xiaomei, Wang Hong, Dong Huan, Gu Xiaofeng, Yu Xiaolin, Liu Yushan
Beijing University of Chinese Medicine, No. 11 on North 3rd Ring Road, Beijing 100029, China.
Department of Respiratory Medicine, Dongfang Hospital Affiliated to Beijing University of Chinese Medicine, No. 6 on 1st District of Fangxingyuan, Beijing 100078, China.
Evid Based Complement Alternat Med. 2019 Jan 3;2019:2710509. doi: 10.1155/2019/2710509. eCollection 2019.
The aim of the current study was to investigate the protective effect of Yangyin Yiqi Mixture (YYYQ) on Bleomycin-induced pulmonary fibrosis in rats based on TGF-1/Smad signal pathway and epithelial to mesenchymal transition (EMT).
120 Wistar rats were randomly divided into six groups: control group, BLM group, BLM + Pred group, BLM+YYYQ-L group, BLM+YYYQ-M group, and BLM+YYYQ-H group. Rats were given an intratracheal instillation of 3 mg/kg BLM to establish the pulmonary fibrosis model and followed by different dosages of YYYQ (11, 22, 44g/kg, via intragastric gavage) or prednisone soluble (4.2mg/kg, via intragastric gavage) or water. After 14 days and 28 days, tissue sections were stained with hematoxylin-eosin and Masson's trichrome to observe histopathological changes. Protein levels of TGF-1, CTGF, Interleukin 18, and hydroxyproline were detected by ELISA method, and mRNA expressions of TGF-1, TRI, TRII, Smad3, Smad7, -SMA, E-cadherin, laminin, and collagen I were detected by RT-PCR.
TGF-1, CTGF, Interleukin 18, and hydroxyproline levels and mRNA expression of TGF-1, TRI, TRII, Smad3, -SMA, laminin, and collagen I were significantly increased ( <0.01), while Smad7 and E-cadherin levels were significantly decreased in BLM group ( <0.01). YYYQ-M and YYYQ-H group had downregulated the TGF-1, CTGF, hydroxyproline contents, and mRNA expression of TGF-1, TRI, TRII, Smad3, -SMA, laminin, and collagen I and upregulated mRNA levels of Smad7 and E-cadherin significantly ( <0.01 or <0.05). The result from the present study, which was also supported by histological evidence, suggested that YYYQ-M group and YYYQ-H group exhibited better treatment effect on Bleomycin-induced pulmonary fibrotic rats when compared to that of BLM + Pred group ( <0.01). Meanwhile, the effect of YYYQ, in three different dosages, on the level of interleukin 18 was not significant.
These results showed that YYYQ has the potential of ameliorating the progression of pulmonary fibrosis, and the mechanism may be related to suppressing TGF-1/Smad signal pathway and EMT in BLM-induced pulmonary fibrosis of rats.
本研究旨在基于转化生长因子 -1（TGF -1）/Smad信号通路和上皮 - 间充质转化（EMT），探讨养阴益气合剂（YYYQ）对博来霉素诱导的大鼠肺纤维化的保护作用。
将120只Wistar大鼠随机分为六组：对照组、博来霉素（BLM）组、BLM + 泼尼松（Pred）组、BLM+YYYQ - 低剂量（L）组、BLM+YYYQ - 中剂量（M）组和BLM+YYYQ - 高剂量（H）组。通过气管内滴注3mg/kg博来霉素建立肺纤维化模型，随后分别给予不同剂量的YYYQ（11、22、44g/kg，灌胃）或泼尼松龙（4.2mg/kg，灌胃）或水。14天和28天后，取组织切片进行苏木精 - 伊红染色和Masson三色染色，观察组织病理学变化。采用酶联免疫吸附测定（ELISA）法检测TGF -1、结缔组织生长因子（CTGF）、白细胞介素18和羟脯氨酸的蛋白水平，采用逆转录 - 聚合酶链反应（RT - PCR）法检测TGF -1、I型转化生长因子受体（TRI）、II型转化生长因子受体（TRII）、Smad3、Smad7、α - 平滑肌肌动蛋白（α - SMA）、E - 钙黏蛋白、层粘连蛋白和I型胶原蛋白的mRNA表达。
BLM组中，TGF -1、CTGF、白细胞介素18和羟脯氨酸水平以及TGF -1、TRI、TRII、Smad3、α - SMA、层粘连蛋白和I型胶原蛋白的mRNA表达显著升高（P <0.01），而Smad7和E - 钙黏蛋白水平显著降低（P <0.01）。YYYQ - M组和YYYQ - H组显著下调了TGF -1、CTGF、羟脯氨酸含量以及TGF -1、TRI、TRII、Smad3、α - SMA、层粘连蛋白和I型胶原蛋白的mRNA表达，并显著上调了Smad7和E - 钙黏蛋白的mRNA水平（P <0.01或P <0.05）。本研究结果也得到组织学证据的支持，表明与BLM + Pred组相比，YYYQ - M组和YYYQ - H组对博来霉素诱导的肺纤维化大鼠表现出更好的治疗效果（P <0.01）。同时，三种不同剂量的YYYQ对白细胞介素18水平的影响不显著。
这些结果表明，YYYQ具有改善肺纤维化进展的潜力，其机制可能与抑制TGF -1/Smad信号通路和大鼠博来霉素诱导的肺纤维化中的EMT有关。
