Title: SIRT1 redresses the imbalance of tissue inhibitor of matrix metalloproteinase-1 and matrix metalloproteinase-9 in the development of mouse emphysema and human COPD.

Authors: Yao, Hongwei; Hwang, Jae-woong; Sundar, Isaac K; Friedman, Alan E; McBurney, Michael W; Guarente, Leonard; Gu, Wei; Kinnula, Vuokko L; Rahman, Irfan

Published In Am J Physiol Lung Cell Mol Physiol, (2013 Nov 01)

Abstract: Sirtuin1 (SIRT1), a protein/histone deacetylase, protects against the development of pulmonary emphysema. However, the molecular mechanisms underlying this observation remain elusive. The imbalance of tissue inhibitor of matrix metalloproteinases (TIMPs)/matrix metalloproteinases (MMPs) plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD)/emphysema. We hypothesized that SIRT1 protects against emphysema by redressing the imbalance between MMPs and TIMPs. To test this hypothesis, SIRT1-deficient and overexpressing/transgenic mice were exposed to cigarette smoke (CS). The protein level and activity of MMP-9 were increased in lungs of SIRT1-deficient mice exposed to CS compared with wild-type (WT) littermates, and these effects were attenuated by SIRT1 overexpression. SIRT1 deficiency decreased the level of TIMP-1, which was augmented in SIRT1 transgenic mice compared with WT littermates by CS. However, the level of MMP-2, MMP-12, TIMP-2, TIMP-3, or TIMP-4 was not altered by SIRT1 in response to CS exposure. SIRT1 reduction was associated with imbalance of TIMP-1 and MMP-9 in lungs of smokers and COPD patients. Mass spectrometry and immunoprecipitation analyses revealed that TIMP-1 acetylation on specific lysine residues was increased, whereas its interaction with SIRT1 and MMP-9 was reduced in mouse lungs with emphysema, as well as in lungs of smokers and COPD patients. SIRT1 deficiency increased CS-induced TIMP-1 acetylation, and these effects were attenuated by SIRT1 overexpression. These results suggest that SIRT1 protects against COPD/emphysema, in part, via redressing the TIMP-1/MMP-9 imbalance involving TIMP-1 deacetylation. Thus redressing the TIMP-1/MMP-9 imbalance by pharmacological activation of SIRT1 is an attractive approach in the intervention of COPD.

PubMed ID: 24039251

MeSH Terms: Amino Acid Sequence; Animals; Emphysema/metabolism*; Emphysema/pathology; Emphysema/physiopathology; Humans; Lung/metabolism; Lung/pathology; Lung/physiopathology; Matrix Metalloproteinase 9/metabolism*; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Molecular Sequence Data; Pulmonary Disease, Chronic Obstructive/metabolism*; Pulmonary Disease, Chronic Obstructive/pathology; Pulmonary Disease, Chronic Obstructive/physiopathology; Sirtuin 1/genetics*; Sirtuin 1/metabolism*; Tissue Inhibitor of Metalloproteinase-1/genetics; Tissue Inhibitor of Metalloproteinase-1/metabolism*; Tobacco Smoke Pollution/adverse effects