出 处:《天津医药》2022年第9期921-926,共6页Tianjin Medical Journal
基 金:贵州省科技计划项目(黔科合基础[2017]1101)。
摘 要:目的探讨抑制miR-33表达对急性呼吸窘迫综合征(ARDS)大鼠肺纤维化的影响及其机制。方法将60只SD大鼠按随机数字表法分成假手术组(Sham组)、ARDS模型组(Model组)、antagomir阴性对照组(antagomir-NC组)和miR-33 antagomir组(antagomir组),每组15只。除Sham组外,其他各组大鼠均通过颈部气管滴注脂多糖(LPS)建立ARDS模型。造模成功后给予miR-33 antagomir或antagomir-NC尾静脉注射。测定动脉血氧分压[p(O_(2))]及氧合指数(OI);HE和Masson染色观察肺组织病理学变化;碱性水解法检测肺组织中羟脯氨酸(Hyp)含量;酶联免疫吸附试验(ELISA)检测肺泡灌洗液中炎性因子白细胞介素(IL)-1β、IL-6和肿瘤坏死因子(TNF)-α水平;实时荧光定量PCR检测肺组织中miR-33表达水平及转化生长因子β1(TGF-β1)、胶原蛋白(Collagen)Ⅰ和CollagenⅢmRNA表达水平;Western blot检测肺组织中TGF-β1、Smad2、p-Smad2、Smad3、p-Smad3和α-平滑肌肌动蛋白(α-SMA)蛋白表达水平。结果与Sham组比较,Model组大鼠中p(O_(2))和OI均降低(P<0.05),肺组织损伤严重,且有明显的胶原纤维沉积,肺组织中Hyp含量及肺泡灌洗液中IL-1β、IL-6和TNF-α水平均升高(P<0.05),肺组织中miR-33和TGF-β1、CollagenⅠ、CollagenⅢmRNA表达水平及TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3和α-SMA蛋白表达水平均增加(P<0.05)。与Model组和antagomir-NC组比较,antagomir组大鼠中p(O_(2))和OI均升高(P<0.05),肺组织损伤明显改善,胶原纤维沉积减少,肺组织中Hyp含量及肺泡灌洗液中IL-1β、IL-6和TNF-α水平均降低(P<0.05),miR-33和TGF-β1、CollagenⅠ、CollagenⅢmRNA表达水平及TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3、α-SMA蛋白表达水平均降低(P<0.05)。结论抑制miR-33表达可能通过抑制TGF-β1/Smad信号通路从而改善ARDS大鼠肺纤维化。Objective To investigate the effect and mechanism of inhibiting miR-33 expression on pulmonary fibrosis in rats with acute respiratory distress syndrome(ARDS).Methods A total of 60 SD rats were divided into the Sham group,the ARDS model group(Model group),the antagomir negative control group(antagomir-NC group)and the miR-33 antagomir group(antagomir group)according to random number table method,with 15 rats in each group.Except for the Sham group,ARDS model was established by endotracheal drop of lipopolysaccharide(LPS)in other groups.After the model was successfully established,miR-33 antagomir or antagomir-NC were injected through tail vein.Arterial partial pressure of oxygen[p(O_(2))]and oxygenation index(OI)were measured.HE staining and Masson staining were used to observe the histopathological changes and the degree of pulmonary fibrosis of lung.The content of hydroxyproline(Hyp)in lung tissue was detected by alkaline hydrolysis method.The levels of interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)in alveolar lavage fluid were detected by ELISA.The mRNA expression levels of miR-33 and TGF-β1,CollagenⅠand CollagenⅢin lung tissues were detected by qPCR.The protein expression levels of TGF-β1,Smad2,p Smad2,Smad3,p-Smad3 andα-smooth muscle actin(α-SMA)were detected by Western blot assay.Results Compared with the Sham group,the level of p(O_(2))and OI were significantly decreased in the Model group(P<0.05).Lung tissue was severely damaged and there were obvious collagen fiber deposition.The Hyp content in lung tissue and levels of IL-1β,IL-6 and TNF-αin alveolar lavage fluid were significantly increased in the Model group(P<0.05).The expression levels of miR33,the mRNA expression levels of TGF-β1,CollagenⅠand CollagenⅢand the protein expression levels of TGF-β1,p Smad2/Smad2,p-Smad3/Smad3 andα-SMA in lung tissue were significantly increased(P<0.05).Compared with the Model group and the antagomir-NC group,the levels of p(O_(2))and OI were significantly increased in the
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