高芳瑜, 周倩文, 田娣, 刘煊, 陈溪渊, 王发选. TGF-β受体阻断剂SB431542对SiO2粉尘诱导矽肺纤维化大鼠相关转录因子表达的影响[J]. 环境与职业医学, 2020, 37(7): 706-711. DOI: 10.13213/j.cnki.jeom.2020.19883
引用本文: 高芳瑜, 周倩文, 田娣, 刘煊, 陈溪渊, 王发选. TGF-β受体阻断剂SB431542对SiO2粉尘诱导矽肺纤维化大鼠相关转录因子表达的影响[J]. 环境与职业医学, 2020, 37(7): 706-711. DOI: 10.13213/j.cnki.jeom.2020.19883
GAO Fang-yu, ZHOU Qian-wen, TIAN Di, LIU Xuan, CHEN Xiyuan, WANG Fa-xuan. Effect of TGF-β receptor blocker SB431542 on expression of related transcription factors in rats with silicosis induced by SiO2 dust[J]. Journal of Environmental and Occupational Medicine, 2020, 37(7): 706-711. DOI: 10.13213/j.cnki.jeom.2020.19883
Citation: GAO Fang-yu, ZHOU Qian-wen, TIAN Di, LIU Xuan, CHEN Xiyuan, WANG Fa-xuan. Effect of TGF-β receptor blocker SB431542 on expression of related transcription factors in rats with silicosis induced by SiO2 dust[J]. Journal of Environmental and Occupational Medicine, 2020, 37(7): 706-711. DOI: 10.13213/j.cnki.jeom.2020.19883

TGF-β受体阻断剂SB431542对SiO2粉尘诱导矽肺纤维化大鼠相关转录因子表达的影响

Effect of TGF-β receptor blocker SB431542 on expression of related transcription factors in rats with silicosis induced by SiO2 dust

  • 摘要: 背景

    矽肺的发病机制尚不明确,且治疗手段有限,较为公认的机制是通过转化生长因子-β(TGF-β)诱导上皮间质转化(EMT)过程。SB431542作为TGF-β特异性受体阻断剂,在多种疾病中可阻断TGF-β/Smad3信号通路及下游的EMT通路,但其在SiO2粉尘诱导矽肺纤维化作用中尚未阐明。

    目的

    探讨TGF-β受体阻断剂SB431542对经SiO2粉尘诱导的矽肺纤维化大鼠转录因子表达的影响。

    方法

    40只SD雄性大鼠随机均分为四组:生理盐水对照组、矽肺模型组、SB431542抑制剂组和抑制剂对照组。对后三组大鼠和生理盐水对照组大鼠采用非暴露式气管注入的方法分别注入游离性SiO2粉尘悬浊液1 mL(50 g·L-1)和等量生理盐水(5 mg·kg-1)。染尘后第7、30天,SB431542抑制剂组腹腔注射SB431542(5 mg·kg-1),抑制剂对照组腹腔注射SB431542助溶剂(5 mg·kg-1)。染尘60 d后取材,取右肺上叶行HE及Masson染色,镜下进行病理观察;取左肺上叶,使用实时定量PCR法检测肺组织中神经型钙黏着蛋白(N-cadherin)、锌指转录因子1(Snail1)、E盒结合锌指蛋白1(ZEB1)、扭曲基因(Twist)的mRNA表达水平,取右肺下叶使用蛋白质印记法检测肺组织中N-cadherin、Snail1、ZEB1、Twist的蛋白表达水平。

    结果

    由肺组织的病理结果中可见,与生理盐水对照组相比,矽肺模型组的肺组织有明显的灰白色矽结节,肺气肿样改变,肺间隔中有部分断裂,肺间质纤维化;SB431542抑制剂组肺组织比抑制剂对照组的肺泡结构稍完整,未见明显矽结节。与生理盐水对照组相比,矽肺模型组N-cadherin和各转录因子(Snail1ZEB1Twist)基因和蛋白水平均升高,mRMA的相对表达水平分别是生理盐水对照组的6.88倍、4.71倍、3.41倍和3.80倍;蛋白的相对表达水平是生理盐水对照组的1.48倍、1.94倍、1.49倍和1.45倍(P < 0.05)。与抑制剂对照组相比,SB431542抑制剂组N-cadherin和各转录因子(Snail1ZEB1Twist)的基因和蛋白水平均降低(P < 0.05)。与抑制剂对照组相比,矽肺模型组各基因和蛋白水平表达水平差异均无统计学意义(P>0.05)。

    结论

    SB431542通过阻断TGF-β与受体结合,使转录因子下调,抑制转录因子诱导的EMT过程,具有抑制矽肺纤维化进展的潜在作用。

     

    Abstract: Background

    The pathogenesis of silicosis is not clear, and the relevant treatment is limited. A recognized mechanism is epithelial-mesenchymal transition (EMT) induced by transforming growth factor-β (TGF-β). SB431542, as a specific receptor blocker of TGF-β, can block TGF-β/Smad3 signaling pathway and downstream EMT pathway in many diseases. However, its role in silicosis induced by SiO2 dust has not been elucidated.

    Objective

    This experiment investigates the effect of SB431542, a specific receptor blocker of TGF-β, on the expression of transcription factors in rats with silicotic fibrosis induced by SiO2 dust.

    Methods

    Forty male SD rats were randomly divided into four groups:a normal saline control group, a silicosis model group, a SB431542 inhibitor group, and an inhibitor control group. Non-exposed intratracheal instillation was used to inject 1 mL (50 g·L-1) of free SiO2 dust suspension into the trachea of rats in all groups except the first group, and the same amount of normal saline (5 mg·kg-1) was injected into the normal saline control group. On the 7th and 30th days after the dust exposure, the SB431542 inhibitor group was injected intraperitoneally with SB431542 (5 mg·kg-1), and the inhibitor control group was injected intraperitoneally with cosolvent of SB431542 (5 mg·kg-1). After 60 d of the dust exposure, the lung tissue samples were isolated, and the upper lobe of the right lung was stained with HE and Masson to observe the pathological changes under microscope. The mRNA expression levels of neuronal cadherin (N-cadherin), zinc finger transcription factor 1 (Snail1), E-box binding zinc finger protein 1 (ZEB1), and twisted gene (Twist) in the upper lobe of the left lung samples were detected by quantitative real-time PCR, and the protein expression levels of N-cadherin, Snail1, ZEB1, and Twist in the lower lobe of the right lung samples were detected by Western blotting.

    Results

    The pathological results showed that compared with the normal saline control group, there were obvious gray-white silicotic nodules, emphysema-like changes, partial rupture of the pulmonary septum, and fibrosis in the pulmonary interstitium in the lung tissues of the silicosis model group; compared with the inhibitor control group, no obvious silicotic nodules were found in the lung tissues of the SB431542 inhibitor group, and the alveolar structure was basically intact. Compared with the normal saline control group, the gene and protein expression levels of N-cadherin and transcription factors (Snail1, ZEB1, and Twist) in the silicosis model group were increased:the relative mRNA expression levels were 6.88, 4.71, 3.41, and 3.80 times higher respectively, and the relative protein expression levels were 1.48, 1.94, 1.49, and 1.45 times higher respectively (P < 0.05). Compared with the inhibitor control group, the gene and protein expression levels of N-cadherin and transcription factors (Snail1, ZEB1, and Twist) were decreased in the SB431542 inhibitor group (P < 0.05). Compared with the inhibitor control group, there were no significant difference in the expression levels of genes or proteins in the silicosis model group (P>0.05).

    Conclusion

    SB431542 can down-regulate the transcription factors and inhibit the EMT induced by the transcription factors by blocking the binding of TGF-β to the receptor, which can potentially inhibit the progression of silicosis.

     

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