环境与职业医学2024，Vol.41Issue(8)：861-866,6.DOI:10.11836/JEOM24031
外泌体源性miRNA-21-5p/Smad7在石英粉尘致大鼠肺纤维化中的作用
Role of exosome-derived miRNA-21-5p/Smad7 in quartz dust-induced pulmonary fibrosis in rats
摘要
Abstract
[Background]Quartz dust cannot be degraded in the lungs,and inhalation of a large amount of quartz dust in the occupational production process will lead to the occurrence of pulmonary fi-brosis,and then develop into silicosis.In recent years,studies have found that exosomes may be involved in the pathogenesis of fibrotic diseases by carrying microribonucleic acid(miRNA),but the mechanism of their actions in silicosis still needs to be studied. [Objective]To investigate the role of exosome-derived miRNA-21-5p/mothers against decapen-taplegic homolog 7(Smad7)in quartz dust-induced pulmonary fibrosis in rats. [Methods]Twenty-four healthy male SD rats were randomly divided into four groups(six rats in each group):control 4-week group,control 16-week group,quartz 4-week group,and quartz 16-week group.At the beginning of the experiment,1 mL of quartz suspension(50 mg·mL-1)and 1 mL of normal saline were injected into the trachea of rats in the quartz group and the control group,respectively,by means of one-time non-exposure intratracheal dust staining.Alveolar lavage was performed at the 4th and 16th weeks after dust staining,the exosomes in lavage solution were extracted by polyethylene glycol(PEG)precipitation,morphological identification was conducted by transmission electron microscopy(TEM),particle size of exosomes was detected by nano-tracking analysis(NTA),and the marker proteins CD9 and CD63 of exosomes were detected by Western blotting(WB).The expression of miRNA-21-5p in exosomes was determined by reverse transcription polymerase chain reaction(RT-PCR).The de-gree of lung tissue injury and fibrosis was observed by hematoxylin-eosin staining(HE)and Masson staining.The collagen content of lung tissue was detected by hydroxyproline(HYP)method.The expression of Smad7 protein in lung tissue was detected by WB. [Results]The results of pathological staining showed that compared with the control group,lung inflammatory cell infiltration,alveolar wall thickening,and collagen increase were observed after 4 weeks of dusting,and collagen deposition and silicon nodules appeared after 16 weeks of dusting.Compared with the control group,the expression level of HYP in the lung tissue of the quartz group was increased after 4 weeks and 16 weeks of dust staining(P<0.05).Transmission electron microscopy showed that exosomes were saucer-shaped,and the average particle size of exosomes was 95.8 nm by NTA.Positive expression of exosome marker proteins CD9 and CD81 was found by WB.Compared with the control group,the expression of exosome-derived miRNA-21-5p in alveolar lavage fluid in the quartz group increased in the 4th week and the 16th week(P<0.05),and the expression of Smad7 protein in lung tissue decreased(P<0.05). [Conclusion]Exosome-derived miRNA-21-5p and Smad7 may be involved in the mechanism of quartz dust-induced pulmonary fibrosis in rats.关键词
石英粉尘/外泌体/miRNA-21-5p/Smad7/肺纤维化Key words
quartz dust/exosome/miRNA-21-5p/Smad7/pulmonary fibrosis分类
预防医学引用本文复制引用
卢炀,丁晓慧,王甜甜,徐萌彤,郝嘉瑞,李文静,宋静..外泌体源性miRNA-21-5p/Smad7在石英粉尘致大鼠肺纤维化中的作用[J].环境与职业医学,2024,41(8):861-866,6.基金项目
国家卫生健康委员会尘肺重点实验室项目(2020-PT320-005) （2020-PT320-005）
山西省自然科学基金面上项目(202303021211123) （202303021211123）
