PMC

SR-AI/II^–/– mice were exposed to 0.3 ppm ozone for 48 hours, after which the AMs were isolated, labeled for MARCO, and analyzed by flow cytometry. Results shown are representative of 2 independent experiments.

. β-epoxide, but not ozone. SR-AI/II^–/– mice received aerosolized leachate from ROFA (100 mg/ml for 1 hour; A), 1 μg i.t. β-epoxide (B), or 0.3 ppm ozone (C) for 48 hours. Number of mice per group is shown for each bar. *P < 0.05 versus treated SR-AI/II^+/+ group; ^#P < 0.05 versus untreated control.

. BAL samples obtained from MARCO^–/– mice 7 hours after i.t. instillation of 1 μg β-epoxide (Exp) or PON-GPC (PON) showed higher levels of neutrophils (A), MIP-2 (B), and total protein (C) compared with controls. Number of mice per group is shown for each bar. *P < 0.05 versus respective treated MARCO^+/+ group; ^#P < 0.05 versus cholesterol (Chol) control.

(A–C) BAL samples obtained from MARCO^–/– mice after exposure to 0.3 ppm ozone for 48 hours showed higher levels of neutrophils (A), total protein (B), and 8-isoprostane (C) compared with controls. (D) BAL samples obtained from MARCO^–/– mice 18 hours after exposure to aerosolized leachate from ROFA (100 mg/ml, 1 hour) showed higher levels of neutrophils compared with controls. Number of mice per group is shown for each bar. *P < 0.05 versus treated MARCO^+/+ group; ^#P < 0.05 versus untreated.

HeJ or congenic ozone-sensitive OuJ mice were exposed to 0.3 ppm ozone for up to 48 hours. Microarray analysis (A) and RT-PCR (B) were performed on total RNA isolated from lung samples and showed increased MARCO mRNA expression in HeJ mice (filled symbols) compared with OuJ mice (open symbols). (C) Western blot analysis of lung tissue obtained after 48 hours of ozone exposure also showed increased MARCO protein expression. (D) Ozone upregulates MARCO on the surface of AMs of C57BL/6 mice exposed to 0.3 ppm ozone for 48 hours, as shown by increased fluorescence after flow cytometric analysis. Results shown are representative of 3 independent experiments. MFI, mean fluorescence intensity. *P < 0.05 versus ozone-treated OuJ; ^#P < 0.05 versus air-exposed control.