As the inhibition of sirtuin-1 induces MMP-9 expression via increased binding of acetylated NF-κB to the MMP-9 promoter (17), as well as regulating of CXCL8 and IL-6 expression via histone deacetylation (48), the down-regulation of sirtuin-1 by miR-570-3p may explain elevation of these proteins in COPD. Here, SIRT1 is linked to chronic obstructive pulmonary disease.