Mechanism of action of mitochondrial DNA in alveolar epithelial type Ⅱ cells in silicotic fibrosis

QIN Yu-fan; XU Shang-cheng

doi:10.11659/jjssx.02E025099

您当前的位置：

首页 >

文章列表页 >

Mechanism of action of mitochondrial DNA in alveolar epithelial type Ⅱ cells in silicotic fibrosis

Basic Research | 更新时间：2025-07-31

- Mechanism of action of mitochondrial DNA in alveolar epithelial type Ⅱ cells in silicotic fibrosis
- JOURNAL OF REGIONAL ANATOMY AND OPERATIVE SURGERY Vol. 34, Issue 8, Pages: 657-662(2025)
- 作者机构：
  
  1.南京医科大学公共卫生学院，江苏南京 211100
  2.重庆市职业病防治院实验医学中心，重庆 400000
- 作者简介：
- 基金信息：
- DOI：10.11659/jjssx.02E025099
  CLC： R134
- Received：19 February 2025，
  
  Published：25 August 2025
- 稿件说明：
移动端阅览
覃宇帆,许商成.Ⅱ型肺泡上皮细胞线粒体DNA在矽肺纤维化中的作用机制[J].局解手术学杂志,2025,34(08):657-662.

QIN Yu-fan,XU Shang-cheng.Mechanism of action of mitochondrial DNA in alveolar epithelial type Ⅱ cells in silicotic fibrosis[J].JOURNAL OF REGIONAL ANATOMY AND OPERATIVE SURGERY,2025,34(08):657-662.
覃宇帆,许商成.Ⅱ型肺泡上皮细胞线粒体DNA在矽肺纤维化中的作用机制[J].局解手术学杂志,2025,34(08):657-662. DOI： 10.11659/jjssx.02E025099.

QIN Yu-fan,XU Shang-cheng.Mechanism of action of mitochondrial DNA in alveolar epithelial type Ⅱ cells in silicotic fibrosis[J].JOURNAL OF REGIONAL ANATOMY AND OPERATIVE SURGERY,2025,34(08):657-662. DOI： 10.11659/jjssx.02E025099.

摘要

目的

探讨Ⅱ型肺泡上皮细胞（AECⅡ）中线粒体DNA（mtDNA）在矽肺纤维化中的作用机制。

方法

本研究分为动物实验和细胞实验。动物实验：将28只C57BL/6小鼠分为生理盐水组（

=14）和矽肺模型组（

=14），采用气管灌注法分别给予50 μL无菌生理盐水和50 μL 50 mg/mL SiO

悬浮液，随后在暴露28 d和56 d后取材，HE染色和Masson染色观察小鼠肺组织病理改变，Western blot检测小鼠肺组织中功能蛋白肺表面活性蛋白-D（SP-D）、涎液化糖链抗原-6（KL-6）和促纤维化蛋白转化生长因子-β1（TGF-β1）表达水平。细胞实验：将AECⅡ细胞系A549暴露在不同浓度SiO

悬浮液中，CCK-8检测细胞活性，DAPI染色观察细胞凋亡情况，Western blot检测细胞相关蛋白表达，JC-1检测线粒体膜电位变化，RT-qPCR检测全细胞、线粒体、胞质和上清中mtDNA水平。采用DnaseⅠ清除mtDNA，并检测细胞相关蛋白表达。

结果

肺组织病理检查显示，SiO

暴露导致小鼠肺组织损伤，出现炎症细胞浸润、硅结节，胶原纤维明显增加；经SiO

暴露后，肺组织中SP-D、KL-6、TGF-β1蛋白表达上调（

0.05）。DAPI染色和CCK-8结果显示，400、800 μg/mL SiO

处理使AECⅡ活性降低，凋亡受损。JC-1检测结果显示，800 μg/mL SiO

暴露导致AECⅡ线粒体膜电位降低（

0.05）。RT-qPCR结果显示，800 μg/mL SiO

暴露导致AECⅡ胞质和上清中mtDNA水平增加（

0.05）。Western blot结果显示，800 μg/mL SiO

暴露导致SP-D、KL-6和TGF-β1蛋白水平增加（

0.05），而DnaseⅠ处理可改善这一现象。

结论

SiO

暴露导致AECⅡ mtDNA逃逸释放并引起AECⅡ功能障碍，从而导致肺纤维化的发生。

Abstract

Objective

To explore the mechanism of action of mitochondrial DNA （mtDNA） of alveolar epithelial type Ⅱ cells （AECⅡ） in silicotic fibrosis.

Methods

This study was divided into the animal experiment and cell experiment. Animal experiment： twenty-eight C57BL/6 mice were randomly divided into the saline group （

=14） and the silicosis model group （

=14），which were given 50 μL of sterile saline and 50 μL of 50 mg/mL of SiO

suspension by tracheal per

fusion respectively. HE staining and Masson staining were performed to observe the histopathological changes of mouse lung tissues after sampling with the exposure of 28 days and 56 days， and Western blot was used to detect the expression levels of functional proteins of pulmonary surfactant protein-D （SP-D）， and Krebs von den Lungen-6 （KL-6）， and fibrotic protein of transforming growth factor-β1 （TGF-β1） in mouse lung tissues. Cell experiment： AECⅡ cell line of A549 was exposed to different concentrations of SiO

suspension. CCK-8 was used to detect cell viability， DAPI staining was used to observe cell apoptosis， Western blot was used to detect related protein expression， JC-1 was used to detect the changes of mitochondrial membrane potential，and RT-qPCR was used to detect mtDNA levels in whole cells，mitochondria，cytoplasm and supernatant.The expression levels of related proteins in AECⅡ were detected by Western blot after cleared mtDNA by DnaseⅠ.

Results

Histopathological examination of lung tissues showed that SiO

exposure led to damage in mice lung tissues， with infiltration of inflammatory cell， silica nodules， and a significant increase of collagen fibers.After SiO

exposure， the protein expressions of SP-D，KL-6 and TGF-β1 in lung tissues were up-regulated （

0.05）.DAPI staining and CCK-8 results showed a reduced activity and impaired apoptosis of AECⅡ after treated with 400 and 800 μg/mL SiO

. JC-1 assay results demonstrated that exposure to 800 μg/mL SiO

caused a decrease of mitochondrial membrane potential in AECⅡ （

0.05）. RT-qPCR results showed that 800 μg/mL SiO

exposure led to increased mtDNA levels in the cytoplasm and supernatant of AECⅡ （

0.05）. Western blot results showed that 800 μg/mL SiO

exposure caused an increase in the levels of SP-D， KL-6， and TGF-β1 proteins，while which were ameliorated by DnaseⅠ treatment.

Conclusion

SiO

exposure results in the escape and release of AECⅡ mtDNA and dysfunction of AECⅡ， thereby leading to the development of pulmonary fibrosis.

关键词

Keywords

references

毛翎，彭莉君，王焕强 . 尘肺病治疗中国专家共识（2018年版）［J］. 环境与职业医学， 2018 ， 35 （ 8 ）： 677 - 689 . doi： 10.13213/j.cnki.jeom.2018.18437 http://dx.doi.org/10.13213/j.cnki.jeom.2018.18437 .

Xie T ， Lynn H ， Parks WC ， et al . Abnormal respiratory progenitors in fibrotic lung injury ［J］. Stem Cell Res Ther ， 2022 ， 13 （ 1 ）： 64 . doi： 10.1186/s13287-022-02737-y http://dx.doi.org/10.1186/s13287-022-02737-y .

Barnes PJ ， Baker J ， Donnelly LE . Cellular senescence as a mechanism and target in chronic lung diseases ［J］. Am J Respir Crit Care Med ， 2019 ， 200 （ 5 ）： 556 - 564 . doi： 10.1164/rccm.201810-1975TR http://dx.doi.org/10.1164/rccm.201810-1975TR .

Gong T ， Liu L ， Jiang W ， et al . DAMP-sensing receptors in sterile inflammation and inflammatory diseases ［J］. Nat Rev Immunol ， 2020 ， 20 （ 2 ）： 95 - 112 . doi： 10.1038/s41577-019-0215-7 http://dx.doi.org/10.1038/s41577-019-0215-7 .

Lyu Y ， Wang T ， Huang S ， et al . Mitochondrial damage-associated molecular patterns and metabolism in the regulation of innate immunity ［J］. J Innate Immun ， 2023 ， 15 （ 1 ）： 665 - 679 . doi： 10.1159/000533602 http://dx.doi.org/10.1159/000533602 .

Hu MM ， Shu HB . Mitochondrial DNA-triggered innate immune response： mechanisms and diseases ［J］. Cell Mol Immunol ， 2023 ， 20 （ 12 ）： 1403 - 1412 . doi： 10.1038/s41423-023-01086-x http://dx.doi.org/10.1038/s41423-023-01086-x .

Pan SW ， Syed RR ， Catanzaro DG ， et al . Circulating mitochondrial cell-free DNA dynamics in patients with mycobacterial pulmonary infections： potential for a novel biomarker of disease ［J］. Front Immunol ， 2022 ， 13 ： 1040947 . doi： 10.3389/fimmu.2022.1040947 http://dx.doi.org/10.3389/fimmu.2022.1040947 .

Giordano L ， Gregory AD ， Perez VM ， et al . Extracellular release of mitochondrial DNA： triggered by cigarette smoke and detected in COPD ［J］. Cells ， 2022 ， 11 （ 3 ）： 369 . doi： 10.3390/cells11030369 http://dx.doi.org/10.3390/cells11030369 .

Huang R ， Shi Q ， Zhang S ， et al . Inhibition of the cGAS-STING pathway attenuates lung ischemia/reperfusion injury via regulating endoplasmic reticulum stress in alveolar epithelial type Ⅱ cells of rats ［J］. J Inflamm Res ， 2022 ， 15 ： 5103 - 5119 . doi： 10.2147/JIR.S365970 http://dx.doi.org/10.2147/JIR.S365970 .

Malainou C ， Abdin SM ， Lachmann N ， et al . Alveolar macrophages in tissue homeostasis， inflammation， and infection： evolving concepts of therapeutic targeting ［J］. J Clin Invest ， 2023 ， 133 （ 19 ）： e170501 . doi： 10.1172/JCI170501 http://dx.doi.org/10.1172/JCI170501 .

Gonzalez R ， Leaffer D ， Chapin C ， et al . Cell fate analysis in fetal mouse lung reveals distinct pathways for TⅠand TⅡcell development ［J］. Am J Physiol Lung Cell Mol Physiol ， 2019 ， 317 （ 5 ）： L653 - L666 . doi： 10.1152/ajplung.00503.2018 http://dx.doi.org/10.1152/ajplung.00503.2018 .

Zhang T ， Zhang J ， Lv C ， et al . Senescent AECⅡ and the implication for idiopathic pulmonary fibrosis treatment ［J］. Front Pharmacol ， 2022 ， 13 ： 1059434 . doi： 10.3389/fphar.2022.1059434 http://dx.doi.org/10.3389/fphar.2022.1059434 .

Li X ， Liu Y ， Cheng L ， et al . Roles of biomarkers in anti-MDA5-positive dermatomyositis， associated interstitial lung disease， and rapidly progressive interstitial lung disease ［J］. J Clin Lab Anal ， 2022 ， 36 （ 11 ）： e24726 . doi： 10.1002/jcla.24726 http://dx.doi.org/10.1002/jcla.24726 .

Wakamatsu K ， Nagata N ， Kumazoe H ， et al . Prognostic value of serial serum KL-6 measurements in patients with idiopathic pulmonary fibrosis ［J］. Respir Investig ， 2017 ， 55 （ 1 ）： 16 - 23 . doi： 10.1016/j.resinv.2016.09.003 http://dx.doi.org/10.1016/j.resinv.2016.09.003 .

Wang M ， Zhang Z ， Liu J ， et al . Gefitinib and fostamatinib target EGFR and SYK to attenuate silicosis： a multi-omics study with drug exploration ［J］. Signal Transduct Target Ther ， 2022 ，13， 7 （ 1 ）： 157 . doi： 10.1038/s41392-022-00959-3 http://dx.doi.org/10.1038/s41392-022-00959-3 .

Song MY ， Wang JX ， Sun YL ， et al . Tetrandrine alleviates silicosis by inhibiting canonical and non-canonical NLRP3 inflammasome activation in lung macrophages ［J］. Acta Pharmacol Sin ， 2022 ， 43 （ 5 ）： 1274 - 1284 . doi： 10.1038/s41401-021-00693-6 http://dx.doi.org/10.1038/s41401-021-00693-6 .

Xia L ， Yan X ， Zhang H . Mitochondrial DNA-activated cGAS-STING pathway in cancer： mechanisms and therapeutic implications ［J］. Biochim Biophys Acta Rev Cancer ， 2024 ， 1880 （ 1 ）： 189249 . doi： 10.1016/j.bbcan.2024.189249 http://dx.doi.org/10.1016/j.bbcan.2024.189249 .

Long G ， Gong R ， Wang Q ， et al . Role of released mitochondrial DNA in acute lung injury ［J］. Front Immunol ， 2022 ， 13 ： 973089 . doi： 10.3389/fimmu.2022.973089 http://dx.doi.org/10.3389/fimmu.2022.973089 .

Tan S ， Chen S . Macrophage autophagy and silicosis：current perspective and latest insights ［J］. Int J Mol Sci ， 2021 ， 22 （ 1 ）： 453 . doi： 10.3390/ijms22010453 http://dx.doi.org/10.3390/ijms22010453 .

Zhao H ， Wang Y ， Qiu T ， et al . Autophagy， an important therapeutic target for pulmonary fibrosis diseases ［J］. Clin Chim Acta ， 2020 ， 502 ： 139 - 147 . doi： 10.1016/j.cca.2019.12.016 http://dx.doi.org/10.1016/j.cca.2019.12.016 .

Ryu C ， Sun H ， Gulati M ， et al . Extracellular mitochondrial DNA is generated by fibroblasts and predicts death in idiopathic pulmonary fibrosis ［J］. Am J Respir Crit Care Med ， 2017 ， 196 （ 12 ）： 1571 - 1581 . doi： 10.1164/rccm.201612-2480OC http://dx.doi.org/10.1164/rccm.201612-2480OC .

Ji Y ， Lin Y ， He J ， et al . Research progress of mitochondria and cytoskeleton crosstalk in tumour development ［J］. Biochim Biophys Acta RevCancer ， 2024 ， 1880 （ 1 ）： 189254 . doi： 10.1016/j.bbcan. 2024.189254 http://dx.doi.org/10.1016/j.bbcan.2024.189254 .

Views

下载量

CSCD

Alert me when the article has been cited

提交

Tools

Publicity Resources

Paraquat promotes epithelial-mesenchymal transition of alveolar epithelial cells through regulating Wnt/β-catenin signaling pathway

Alleviating effect of atorvastatin combined with cyclosporine A on pulmonary fibrosis in paraquat poisoned rats

Related Author

ZHAO Chun-yan

LIU Chang

ZHU Zhong-li

WANG Xiao-fen

ZHU Guo-yun

LI Fu-xiang

SHI Jie

LIU Wei

Related Institution

Department of Critical Care Medicine，Chengdu Military General Hospital

Department of Pharmacy,Ministry of Western Medicine,Central Hospital of Enshi Tujia and Miao Autonomous Prefecture

Department of Radiology,China Resources WISCO General Hospital

Department of Pharmacy,Women and Children’s Hospital of Enshi Central Hospital

⁰