SIRT1 and chronic obstructive pulmonary disease: In the lungs of smokers and COPD patients, as well as in bronchial epithelial and monocyte-macrophages cell lines, modifications of SIRT1 (such as nitration of tyrosine residues and carbonylation, formation of 4-hydroxy-2-nonenal adducts with cysteine, lysine, and histidine) have been described [37].