FGF-21和Nrf2对博莱霉素诱导的小鼠肺纤维化的影响

Effects of FGF-21 and Nrf2 on BLM-induced pulmonary fibrosis in mice

目的:研究成纤维细胞生长因子21(FGF-21)对博莱霉素(BLM)诱导的小鼠肺纤维化炎症应答及氧化应激的影响,并探讨其抗肺纤维化的作用机制。方法:建立BLM诱导的小鼠肺纤维化的模型,40只小鼠随机分为对照组、BLM组及FGF-21(1、2及5 mg/kg)+BLM组。Western blot检测I型胶原蛋白(collagen I)、纤连蛋白(fibronectin)和核因子E2相关因子2(Nrf2)蛋白表达水平。DCFH-DA染色检测活性氧簇(ROS)的生成。ELISA用于测定肺组织炎症因子的表达。试剂盒检测各组小鼠肺组织中的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GPx)活性和羟脯氨酸(HYP)含量。结果:FGF-21处理显著降低BLM诱导的肺组织炎症介质肿瘤坏死因子α、白细胞介素1β和白细胞介素6的表达水平,减少ROS及MDA的含量,并增加抗氧化酶系统SOD和GPx的活性(P <0. 05)。同时,FGF-21下调BLM诱导的collagen I和fibronectin,并减少TGF-β1及HYP的含量。Nrf2沉默能够逆转FGF-21的抗纤维化作用。结论:FGF-21通过激活Nrf2信号抑制炎症应答进程,减轻氧化损伤,减少细胞外基质沉积,从而缓解BLM诱导的肺纤维化。这可能为肺间质纤维化治疗提供新的靶点。

AIM:To investigate the effect of fibroblast growth factor-21(FGF-21)on bleomycin(BLM)-induced inflammatory response and oxidative stress in the lung,and to further explore the molecular mechanism of FGF-21against pulmonary fibrosis.METHODS:The lung fibrosis model was induced by BLM intratracheal instillation.A total of40mice were randomly divided into control group,BLM group,FGF-21(1,2and5mg/kg)+BLM groups.Western blot was used to detected the protein expression of collagen I,fibronectin and nuclear factor E2-related factor2(Nrf2).The reactive oxygen species(ROS)production was measured by DCFH-DA staining.The levels of inflammatory cytokines were measured by ELISA.The content of malondialdehyde(MDA),the activity of superoxide dismutase(SOD)and glutathione peroxidase(GPx),and the content of hydroxyproline(HYP)were detected by commercially available assay kits.RESULTS:Treatment with FGF-21notably attenuated BLM-induced the expression levels of inflammatory mediators tumor necrosis factor-α,interleukin-1βand interleukin-6in the lung tissue.In addition,FGF-21treatment remarkably reduced the generation of ROS and the content of MDA trigged by BLM,accompanied with the enhanced activity of anti-oxidative enzymes SOD and GPx(P<0.05).Furthermore,treatment with FGF-21obviously reduced the extracellular matrix(ECM)accumulation by suppressing the expression of collagen I and fibronectin induced by BLM,accompanied with the decreases in the levels of TGF-β1and HYP.Silencing of Nrf2expression abolished the protective effect of FGF-21.CONCLUSION:FGF-21relieves BLM-induced pulmonary fibrosis by reducing the inflammatory response,mitigating oxidative damage and decreasing the ECM deposition via Nrf2activation,thus providing the basis for the therapeutic effect of FGF-21on the lung fibrosis.