Sirt1 regulation of TFPI, PAI-1 and TF expression in the lung. Sirt1^+/+ and Sirt1^−/− littermates were exposed to PBS or PM_2.5 (100 μg) by intranasal instillation. Twenty-four hours later, lungs were collected. TFPI (A) and TF (B) expression was examined by immunoblotting. The blots and normalized bar graphs show TFPI and TF expression. Data are presented as mean + SEM (n ≥ 10 mice/group; *P < .05). (C) Lung and plasma PAI-1 levels were assessed by ELISA. Data are presented as mean + SEM (n = 8 mice/group; *P < .05).