Asbestos-induced pulmonary fibrosis is augmented in 8-oxoguanine DNA glycosylase knockout mice

Paul Cheresh, Luisa Morales-Nebreda, Seok Jo Kim, Anjana Yeldandi, David B. Williams, Yuan Cheng, Gökhan M. Mutlu, G. R. Scott Budinger, Karen Ridge, Paul T. Schumacker, Vilhelm A. Bohr, David W. Kamp*

*Corresponding author for this work

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Asbestos causes asbestosis and malignancies by mechanisms that are not fully established. Alveolar epithelial cell (AEC) injury and repair are crucial determinants of the fibrogenic potential of noxious agents such as asbestos. We previously showed that mitochondrial reactive oxygen species mediate asbestos-induced AEC intrinsic apoptosis and that mitochondrial human 8-oxoguanine-DNA glycosylase 1 (OGG1), a DNA repair enzyme, prevents oxidant-induced AEC apoptosis.We reasoned that OGG1 deficiency augments asbestos-induced pulmonary fibrosis. Compared with intratracheal instillation of PBS (50 μ1) or titanium dioxide (100 μg/50 μ1), crocidolite or Libby amphibole asbestos (100 μg/50 μ1) each augmented pulmonary fibrosis in wild-type C57BL/6J (WT) mice after 3 weeks as assessed by histology, fibrosis score, lung collagen via Sircol, and type 1 collagen expression; these effects persisted at 2 months. Compared with WT mice, Ogg1 homozygous knockout (Ogg1-/-) mice exhibit increased pulmonary fibrosis after crocidolite exposure and apoptosis in cells at the bronchoalveolar duct junctions as assessed via cleaved caspase-3 immunostaining. AEC involvement was verified by colocalization studies using surfactant protein C. Asbestos increased endoplasmic reticulum stress in the lungs of WT and Ogg1-/- mice. Compared with WT, alveolar type 2 cells isolated from Ogg1-/- mice have increased mtDNA damage, reduced mitochondrial aconitase expression, and increased P53 and cleaved caspase-9 expression, and these changes were enhanced 3 weeks after crocidolite exposure. These findings suggest an important role forAECmtDNAintegrity maintained byOGG1in the pathogenesis of pulmonary fibrosis that may represent a novel therapeutic target.

Original languageEnglish (US)
Pages (from-to)25-36
Number of pages12
JournalAmerican journal of respiratory cell and molecular biology
Volume52
Issue number1
DOIs
StatePublished - Jan 1 2015

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Keywords

  • 8-oxyguanosine DNA glycosylase
  • Asbestosis
  • Mitochondria
  • Pulmonary fibrosis

ASJC Scopus subject areas

  • Molecular Biology
  • Pulmonary and Respiratory Medicine
  • Clinical Biochemistry
  • Cell Biology

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