SIRT1 and chronic obstructive pulmonary disease: Most importantly, transfection of COPD small airway epithelial cells with an antagomiR against miR-34a or miR-570 not only restores expression of SIRT1 and SIRT6, but also reduces markers of cellular senescence (p16INK4, p21CIP1, SASP production, and SA-β-galactosidase).121