Jablonski Renea P, Kim Seok-Jo, Cheresh Paul, Williams David B, Morales-Nebreda Luisa, Cheng Yuan, Yeldandi Anjana, Bhorade Sangeeta, Pardo Annie, Selman Moises, Ridge Karen, Gius David, Budinger G R Scott, Kamp David W
Department of Medicine, Division of Pulmonary and Critical Care Medicine, Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, USA.
Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
FASEB J. 2017 Jun;31(6):2520-2532. doi: 10.1096/fj.201601077R. Epub 2017 Mar 3.
Alveolar epithelial cell (AEC) mitochondrial dysfunction and apoptosis are important in idiopathic pulmonary fibrosis and asbestosis. Sirtuin 3 (SIRT3) detoxifies mitochondrial reactive oxygen species, in part, by deacetylating manganese superoxide dismutase (MnSOD) and mitochondrial 8-oxoguanine DNA glycosylase. We reasoned that SIRT3 deficiency occurs in fibrotic lungs and thereby augments AEC mtDNA damage and apoptosis. Human lungs were assessed by using immunohistochemistry for SIRT3 activity acetylated MnSOD Murine AEC SIRT3 and cleaved caspase-9 (CC-9) expression were assayed by immunoblotting with or without SIRT3 enforced expression or silencing. mtDNA damage was measured by using quantitative PCR and apoptosis ELISA. Pulmonary fibrosis after asbestos or bleomycin exposure was evaluated in 129SJ/wild-type and SIRT3-knockout mice ( ) by using fibrosis scoring and lung collagen levels. Idiopathic pulmonary fibrosis lung alveolar type II cells have increased MnSOD acetylation compared with controls. Asbestos and HO diminished AEC SIRT3 protein expression and increased mitochondrial protein acetylation, including MnSOD SIRT3 enforced expression reduced oxidant-induced AEC OGG1 acetylation, mtDNA damage, and apoptosis, whereas SIRT3 silencing promoted these effects. Asbestos- or bleomycin-induced lung fibrosis, AEC mtDNA damage, and apoptosis in wild-type mice were amplified in animals. These data suggest a novel role for SIRT3 deficiency in mediating AEC mtDNA damage, apoptosis, and lung fibrosis.-Jablonski, R. P., Kim, S.-J., Cheresh, P., Williams, D. B., Morales-Nebreda, L., Cheng, Y., Yeldandi, A., Bhorade, S., Pardo, A., Selman, M., Ridge, K., Gius, D., Budinger, G. R. S., Kamp, D. W. SIRT3 deficiency promotes lung fibrosis by augmenting alveolar epithelial cell mitochondrial DNA damage and apoptosis.
肺泡上皮细胞（AEC）的线粒体功能障碍和凋亡在特发性肺纤维化和石棉肺中具有重要意义。沉默调节蛋白3（SIRT3）部分通过使锰超氧化物歧化酶（MnSOD）和线粒体8-氧代鸟嘌呤DNA糖基化酶去乙酰化来清除线粒体活性氧。我们推测纤维化肺中存在SIRT3缺乏，从而加剧AEC线粒体DNA损伤和凋亡。通过免疫组织化学评估人肺组织中SIRT3活性、乙酰化MnSOD。通过免疫印迹法检测有无SIRT3强制表达或沉默情况下小鼠AEC中SIRT3和裂解的半胱天冬酶-9（CC-9）的表达。使用定量PCR测量线粒体DNA损伤，采用ELISA检测凋亡情况。通过纤维化评分和肺胶原蛋白水平评估129SJ/野生型和SIRT3基因敲除小鼠在接触石棉或博来霉素后的肺纤维化情况。与对照组相比，特发性肺纤维化肺的II型肺泡细胞中MnSOD乙酰化增加。石棉和过氧化氢减少AEC中SIRT3蛋白表达并增加线粒体蛋白乙酰化，包括MnSOD。SIRT3强制表达减少氧化剂诱导的AEC中OGG1乙酰化、线粒体DNA损伤和凋亡，而SIRT3沉默则促进这些效应。在野生型小鼠中，石棉或博来霉素诱导的肺纤维化、AEC线粒体DNA损伤和凋亡在基因敲除动物中加剧。这些数据表明SIRT3缺乏在介导AEC线粒体DNA损伤、凋亡和肺纤维化中具有新作用。-雅布隆斯基，R.P.，金，S.-J.，切雷什，P.，威廉姆斯，D.B.，莫拉莱斯-内夫雷达，L.，程，Y.，耶尔丹迪，A.，博拉代，S.，帕尔多，A.，塞尔曼，M.，里奇，K.，朱斯，D.，布丁格，G.R.S.，坎普，D.W. SIRT3缺乏通过加剧肺泡上皮细胞线粒体DNA损伤和凋亡促进肺纤维化。
