基于TGF-β通路探讨瓜蒌薤白汤对肺纤维化的作用机制

Effect of Gualou Xiebai Decoction(瓜蒌薤白汤)on Idiopathic Pulmonary Fibrosis Based on TGF-βSignaling Pathway

目的探索瓜蒌薤白汤对肺纤维化的作用机制。方法将SPF级SD大鼠分为空白组(Control)、模型组(Mod⁃el)、吡非尼酮组(Pirfenidone 0.15 g·kg^(-1))、瓜蒌薤白汤低剂量组(GLXB-L 2.4 g·kg^(-1))、瓜蒌薤白汤高剂量组(GLXB-H 4.8 g·kg^(-1))。除空白组外,其余各组大鼠采用一次性向气管内滴注博来霉素复制特发性肺纤维化模型。造模第2天,开始灌胃给予各组大鼠相应药物,连续14、28 d。末次给药后,取材。酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)检测血清和肺泡灌洗液白细胞介素-4(interleukin-4,IL-4)、IL-6、IL-8水平;Masson染色检测大鼠肺组织中胶原纤维和肌纤维;免疫荧光法检测大鼠肺组织TGF-β、α-SMA蛋白表达;实时荧光定量PCR(quantitative real-time PCR,RT-PCR)检测大鼠肺脏TNF-αmRNA、IL-4 mRNA、IL-6 mRNA表达。结果博来霉素致大鼠肺纤维化模型制备成功,瓜蒌薤白汤可降低肺纤维化模型大鼠血清和肺泡灌洗液IL-4、IL-6、IL-8水平,下调肺组织TGF-β、α-SMA蛋白表达,降低TNF-αmRNA、IL-4 mRNA、IL-6 mRNA表达水平,缓解肺组织纤维化病变,且以瓜蒌薤白汤高剂量组效果明显。结论瓜蒌薤白汤可以通过抑制TGF-β信号通路,干预气道炎症反应,减少胶原沉积,从而干预肺纤维化进程。

Objective This study aims to explore the mechanism of Gualou Xiebai Decoction(瓜蒌薤白汤)against idiopathic pulmonary fibrosis.Methods The SD rats of SPF grade were divided into control group,model group,pirfenidone group(0.15 g·kg^(-1)),Gualou Xiebai Decoction low-dose group(GLXB-L,2.4 g·kg^(-1))and high-dose group(GLXB-H,4.8 g·kg^(-1)).The model of pulmonary fibrosis was established by intratracheal instillation of bleomycin in all groups except the control group.Since the second day of modeling,the corresponding drugs were administered separately by intragastric administration,once a day for 14 days and 28 days.After the last administration,the rats were sacrificed for sample collection.Enzyme-linked immunosor⁃bent assay(ELISA)was employed to detect the levels of interleukin-4(IL-4),interleukin-6(IL-6)and interleukin-8(IL-8)in serum and bronchoalveolar lavage fluid(BALF).Masson staining was performed to detect collagen fibers and muscle fibers in lung tissue.The protein expressions of transforming growth factor-β(TGF-β)andα-smooth muscle actin(α-SMA)in lung tissue was detected by immunofluorescence method.The expressions of TNF-αmRNA,IL-4mRNA and IL-6mRNA in the lung of rats were detected by quantitative real-time PCR(RT-PCR).Results These results indicated that the model of bleomycin-induced pulmonary fibrosis in rats was successfully established.Gualou Xiebai Decoction can reduced the levels of IL-4,IL-6 and IL-8 in serum and BALF,down-regulated the protein levels of TGF-βandα-SMA in lung tis⁃sue,and alleviated fibrotic lesions in lung tissue,and the GLXB-H had obvious effect.Conclusion These results indicated that Gualou Xiebai Decoction could restrain the progression of pulmonary fibrosis by inhibiting TGF-βsignaling pathway,interfering with airway inflammation and reducing collagen deposition.