SIRT3 and chronic obstructive pulmonary disease: Consistent with this finding, Sirt3 and SOD protein expression is significantly decreased in the airway epithelia of CS-induced COPD rats and in the lungs of aged mice [81], while Sirt3 overexpression protects mitochondria from oxidative damage in CS extract-treated human airway epithelial cells by decreasing SOD acetylation [82].