外源性抗转化生长因子-β_1抗体对新生大鼠高浓度氧致肺纤维化的影响

The effects of anti-TGF-β_1 on hyperoxic lung fibrosis in neonatal rats

目的观察不同剂量的外源性抗转化生长因子-β1(TGF-β1)抗体作用下,TGF-β1在新生SD大鼠高浓度氧(高氧,>95%O2)致肺纤维化中的表达,了解不同剂量的外源性抗TGF-β1抗体在高氧致肺纤维化中的作用。方法将120只足月新生SD大鼠随机分为6组:空气对照组(Ⅰ组),高氧组(Ⅱ组),高氧+抗TGF-β1抗体0.1mg.kg-1组(Ⅲ组),高氧+抗TGF-β1抗体0.2mg.kg-1组(Ⅳ组),高氧+抗TGF-β1抗体0.4mg.kg-1组(Ⅴ组),高氧+抗TGF-β1抗体0.8mg.kg-1组(Ⅵ组),每组20只。观察及检测高氧暴露3、7、14和28d各组大鼠肺组织病理改变以及TGF-β1免疫组化染色。结果Ⅱ、Ⅲ、Ⅳ组3和7d时表现为明显的急性炎症改变,肺组织水肿、渗出、出血和肺泡间隔轻度增厚,14d时急性炎症减轻而肺组织中TGF-β1表达呈强阳性;28d时出现明显的胶原沉积,形成纤维化。Ⅴ、Ⅵ组3、7、14和28d时相点TGF-β1的表达明显减弱,与Ⅰ组差异无统计学意义;病理改变示早期有轻度炎症反应,14和28d无明显成纤维细胞增生及胶原生成未形成肺纤维化。结论新生SD大鼠连续吸入高氧后可导致急、慢性肺损伤。高氧暴露可刺激肺部产生过量的TGF-β1TGF-β1是与纤维化关系最密切的TGF-β亚型,可促进成纤维细胞分化、生长和增殖。高氧暴露时给予适当剂量外源性抗TGF-β1抗体可减轻新生SD大鼠急性肺损伤,从而减轻肺纤维化。应用外源性抗TGF-β1抗体干预对高氧致肺纤维化损伤有保护作用。

Objeotive To explore： （1） Role of various dosage ectogenic anti-TGF-β1 in hyperoxic lung fibrosis in neonatal rats. （2） Effect of the expression level of TGF-β1 on hyperoxic lung fibrosis of rats treated with various dosage ectogenic anti- TGF-β1. Methods 120 Sprague-Dawley（SD） rats younger than 12 hours old were enrolled in this study. The neonatal rats were divided into 6 groups randomly： normal concentration O2 control group（ group Ⅰ ） ; 〉 95% O2 control group（ group Ⅱ ） ; 〉 95% O2 ＋ anti-TGF-β1 0.1mg.kg^-1 （groupⅢ） ; 〉95%O2 ＋ anti-TGF-β1 0.2 mg-kg^-1（group Ⅳ） ; 〉95%O2 ＋ anti-TGF-β1 0. 4 mg·kg^-1 （ group Ⅴ ） ; 〉 95% O2 ＋ anti-TGF-β1 0. 8mg·kg^-1 （ group Ⅵ ）. Group Ⅰ was placed in the common room. Group Ⅱ , Ⅲ, Ⅳ, Ⅴand Ⅵ were placed into oxygen cabins and exposed to 〉 95% O2 for 3 days, at same time, neonatal rats received nebulization therapy with various dosage anti-TGF-β1 once a day. 3 days,7 days,14 days and 28 days after exposure to high concentration oxygen（ O2 〉 95% ）, the changes of the pathologic alteration in lung were measured, and the expression levels of TGF-β1 were measured by immunohistochemistry. Results On day 3 and day 7, the lungs of group Ⅱ , Ⅲ, Ⅳ, Ⅴ and Ⅵ neonatal rats showed acute inflammations. Microvessel hyperemia, edema,inflammatory cell infiltration, hemorrhage were found by using light microscope and transmission electron microscope, but the expression levels of TGF-β1 were obviously increased in the lungs of group Ⅱ , Ⅲand Ⅳ rats. On day 14, edema,inflammatory cell infiltration,hemorrhage were reduced while marked fibrosis changes were seen in lung, the expression levels of TGF-β1 were hightest; On day 28 there were obvious inflammations and expanded alveolus alternations and strong express of TGF-β1 in group Ⅱ, Ⅲ and Ⅳ than other groups. There was no obviously inflammation and expression of TGF-β1 in group Ⅰ ,There was no significant fibrosis on day 14 and day 28 in group Ⅴ and Ⅵ comparing with the control,the expression level of TGF-β1 was not increased on day 14 and day 28 in group Ⅴ, and no ECM and lung fibrosis were found by using light microscope and transmission electron microscope. Conclusions Hyperoxia could cause acute or chronic lung injury. Hyperoxia could obviously increase the expression level of TGF-β1 and cause lung fibrosis, which suggested TGF-β1 has a key role in fibrosis. Anti-TGF-β1 could inhibit the ALI and lung fibrosis. Anti-TGF-β1 could protect against lung fibrosis and exceptional alveolus development, which suggested Anti-TGF-β1 may have a key role in hyperoxic-induced lung fiborsis.