摘要
目的:探讨下调AlkB同源物5(ALKBH5)在肺纤维化(pulmonary fibrosis,PF)大鼠中的作用,并基于转化生长因子β1(TGF-β1)/Smad信号通路探讨其潜在的作用机制。方法:采用气管内滴注博来霉素制备PF大鼠模型。将造模成功的SD大鼠分为模型组(PF+不给予任何药物处理)、si-NC组(PF+转染si-NC,尾静脉注射)、si-ALKBH5组(PF+转染si-ALKBH5,尾静脉注射)和通路激活剂组(PF+转染si-ALKBH5+30mg/kg的TGF-β1通路激活剂SRI-011381,尾静脉注射)。另选12只正常大鼠作为对照组。采用RT-qPCR方法检测肺组织中ALKBH5 mRNA、诱导型一氧化氮合酶(iNOS)mRNA、白细胞分化抗原86(CD86)mRNA、A精氨酸酶-1(Arg-1)mRNA、甘露糖受体(CD206)mRNA水平;肺功能检测仪检测各组大鼠组织衰减(G)、呼吸系统阻力(Rrs)、呼吸系统顺应性(Crs)和组织弹性(H);采用HE、Masson染色进行肺脏病理组织学分析;采用Western Blot法检测ALKBH5、I型胶原蛋白(Col I)、纤连蛋白(FN)、α-平滑肌肌动蛋白(α-SMA)和TGF-β1/Smad通路相关蛋白表达水平。结果:相较于对照组,模型组大鼠肺结构被破坏,肺泡间隔增厚,肺泡上皮细胞坏死,G、Crs、Arg-1 mRNA、CD206 mRNA水平显著降低(P<0.05),ALKBH5 mRNA及蛋白、Rrs、H、胶原纤维沉积、Col I、FN、α-SMA、iNOS mRNA、CD86 mRNA、TGF-β1、p-Smad2、p-Smad3水平显著升高(P<0.05);相较于模型组和si-NC组,si-ALKBH5组和通路激活剂组肺泡隔轻度增厚,肺组织结构较为完整,G、Crs、Arg-1 mRNA、CD206 mRNA水平显著增加(P<0.05),ALKBH5 mRNA及蛋白、Rrs、H、胶原纤维沉积、Col I、FN、α-SMA、iNOS mRNA、CD86 mRNA、TGF-β1、p-Smad2、p-Smad3水平显著降低(P<0.05);相较于通路激活剂组,si-ALKBH5组大鼠肺组织损伤程度有所改善,G、Crs、Arg-1 mRNA、CD206 mRNA水平显著增加(P<0.05),ALKBH5 mRNA及蛋白、Rrs、H、胶原纤维沉积、Col I、FN、α-SMA、iNOS mRNA、CD86 mRNA、TGF-β1、p-Smad2、p-Smad3水平显著降低(P<0.05)。结论:下调ALKBH5能够缓解肺组织病理损伤和胶原沉积,减轻肺功能损伤,抑制大鼠PF,抑制巨噬细胞向M2型极化,其机制可能与抑制TGF-β1/Smad信号通路有关。
Objective:To explore the role of downregulating AlkB homolog 5(ALKBH5)in rats with pulmonary fibrosis(PF)and its potential mechanism based on the transforming growth factor-β1(TGF-β1)/Smad signaling pathway.Methods:A rat model of PF was established by intratracheal instillation of bleomycin.Successfully modeled Sprague-Dawley(SD)rats were divided into the model group(PF+no drug treatment),si-NC group(PF+transfection with si-NC via tail vein injection),si-ALKBH5 group(PF+transfection with si-ALKBH5 via tail vein injection),and pathway activator group(PF+transfection with si-ALKBH5+30 mg/kg TGF-β1 pathway activator SRI-011381 via tail vein injection).Another 12 normal rats were selected as the control group.RT-qPCR was used to detect the mRNA levels of ALKBH5,inducible nitric oxide synthase(iNOS),cluster of differentiation 86(CD86),arginase-1(Arg-1),and mannose receptor(CD206)in lung tissues.A pulmonary function detector was used to measure tissue damping(G),respiratory system resistance(Rrs),respiratory system compliance(Crs),and tissue elastance(H)in rats of each group.Hematoxylin-Eosin(HE)staining and Masson staining were performed for histopathological analysis of the lungs.Western Blot was used to detect the expression levels of ALKBH5,type I collagen(Col I),fibronectin(FN),α-smooth muscle actin(α-SMA),and proteins related to the TGF-β1/Smad pathway.Results:Compared with the control group,the lung structure of rats in the model group was damaged,with thickened alveolar septa and necrosis of alveolar epithelial cells;the levels of G,Crs,Arg-1 mRNA,and CD206 mRNA were significantly decreased(P<0.05);while the levels of ALKBH5 mRNA and protein,Rrs,H,collagen fiber deposition,Col I,FN,α-SMA,iNOS mRNA,CD86 mRNA,TGF-β1,p-Smad2,and p-Smad3 were significantly increased(P<0.05).Compared with the model group and si-NC group,the alveolar septa in the si-ALKBH5 group and pathway activator group were slightly thickened,and the lung tissue structure was relatively intact;the levels of G,Crs,Arg-1 mRNA,and CD206 mRNA were significantly increased(P<0.05);while the levels of ALKBH5 mRNA and protein,Rrs,H,collagen fiber deposition,Col I,FN,α-SMA,iNOS mRNA,CD86 mRNA,TGF-β1,p-Smad2,and p-Smad3 were significantly decreased(P<0.05).Compared with the pathway activator group,the degree of lung tissue injury in the si-ALKBH5 group was improved;the levels of G,Crs,Arg-1 mRNA,and CD206 mRNA were significantly increased(P<0.05);while the levels of ALKBH5 mRNA and protein,Rrs,H,collagen fiber deposition,Col I,FN,α-SMA,iNOS mRNA,CD86 mRNA,TGF-β1,p-Smad2,and p-Smad3 were significantly decreased(P<0.05).Conclusion:Downregulating ALKBH5 can alleviate pathological damage and collagen deposition in lung tissue,reduce lung function impairment,inhibit PF in rats,and suppress the polarization of macrophages to the M2 type.The mechanism may be related to the inhibition of the TGF-β1/Smad signaling pathway.
作者
岱德羽
党慧
王雪
王春雨
侯冬华
DAI Deyu;DANG Hui;WANG Xue(The First Affiliated Hospital of Harbin Medical University,Heilongjiang Harbin 150001,China)
出处
《河北医学》
2025年第10期1625-1632,共8页
Hebei Medicine
基金
哈尔滨医科大学附属第一医院科研创新基金,(编号:2023B16)。
