基于SOCS对JAK/STAT的负调控探讨镰形棘豆总黄酮对肺纤维化 TGF-β1/Smads信号转导的作用

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fatal and unidentified lung disease. In recent years, studies have shown that the inflammatory response is crucial in the process of IPF. In the complex inflammatory signaling pathway, JAK/STAT mediates intracellular signal transduction of multiple cytokines, which is the main signaling pathway for the development of IPF. It has been found that SOCS protein has a negative regulation on the JAK/STAT pathway. Therefore, the negative regulation of the JAK/STAT pathway by SOCS is used to inhibit the intracellular signal transduction of inflammatory factors and alleviate the IPF process. In recent years, studies have found that Tibetan medicine has achieved good results in the treatment of IPF, and its side effects are relatively few. Therefore, it is of great significance to actively seek and prevent and postpone IPF's Tibetan medicine. The subject of choice with the anti-inflammatory effect of total flavonoids of Oxytropis falcata Bunge as the research object, through the bleomycin induced pulmonary fibrosis rat model and TGF- beta 1 in vitro lung fibroblast cell line, around the "SOCS/JAK/STAT" and "TGF- beta signaling pathway 1/Smads signaling pathway by the experimental technology of fibrosis. Modern molecular biology, from the overall level, cell level, total flavonoids of Oxytropis falcata on inflammation mediated IPF targets and molecular mechanisms, and provide scientific basis for its clinical application, provides a new research idea for the prevention and treatment of IPF by tcm.

特发性肺纤维化（IPF）是一种慢性、进展性、致死性且病因不明的肺部疾病。研究发现,炎症反应在IPF过程中至关重要。在炎症信号通路中，JAK/STAT介导的胞内信号转导，是IPF发生发展的主要信号通路。有研究发现，SOCS蛋白可负调控JAK/STAT通路。因此，通过SOCS对JAK/STAT通路的负调控来阻抑炎症因子的胞内信号转导，可缓解IPF进程。研究表明藏药在治疗IPF方面疗效较好，副作用少。本课题选择具有“抗炎”作用的藏药镰形棘豆总黄酮为研究对象，通过博来霉素所致肺纤维化大鼠模型及TGF-β1诱导体外培养的肺成纤维细胞株，围绕“SOCS/JAK/STAT”炎症信号通路和“TGF-β1/Smads”纤维化信号通路，利用现代分子生物学实验技术，从整体和细胞水平，探讨镰形棘豆总黄酮抗炎症介导的IPF的作用靶点和分子机制，为其临床应用提供科学依据，为防治IPF的研究提供一条新思路。

本课题将特发性肺纤维化“炎症反应”机制和“火热内生，灼伤肺络”中医病机理论相结合，选择具有“清热解毒”、“抗炎”作用的镰形棘豆总黄酮为研究对象。采用博来霉素诱导的肺纤维化大鼠模型，以及TGF-β1诱导体外培养的人肺成纤维细胞，围绕“SOCS/JAK/STAT”炎症信号通路及“TGF-β1/Smads”纤维化信号通路，在体内实验中，观察肺纤维化大鼠肺功能、BALF细胞分类计数，HE染色观察肺组织肺泡炎程度、Masson染色观察肺组织胶原纤维沉积情况，透射电镜观察肺组织超微结构变化；在体外实验中，倒置显微镜观察细胞形态变化，流式检测细胞凋亡情况，CCK8法检测细胞活力；并通过免疫组化、PCR、Western blot等实验技术检测炎症因子：MCP-1、TNF-α、IL-1β、ICAM-1，炎症通路：SOCS3、JAK1、STAT1、p-JAK1、p-STAT1，胶原蛋白：α-SMA、Ⅰ型胶原、Ⅲ型胶原、MMP-1，MMP-9以及纤维化通路：TGF-RⅠ、Smad2、Smad3、p-Smad2、p-Smad3、Smad7的表达。通过体内外实验共同证实了镰形棘豆总黄酮可通过影响SOCS3的表达负调控JAK1/STAT1信号通路抑制相关炎症因子的表达，同时可抑制TGF-β1/Smads纤维化信号通路的激活，延缓特发性肺纤维化进展，对防治特发性肺纤维化有一定的意义。