Figure 1.

Upregulation of heme oxygenase-1 (HO-1) by mevastatin (MVS) attenuated tumor necrosis factor (TNF)-α-induced intercellular adhesion molecule (ICAM)-1 expression associated with monocyte adhesion. (A) human pulmonary alveolar epithelial cells (HPAEpiCs) were incubated with different concentrations of TNF-α (15, 5, 1, or 0.3 ng/mL) for the indicated time intervals. The levels of ICAM-1 and β-actin expression were determined by Western blot. (B–D) Cells were pretreated MVS for 1 h, then incubated with or without tin protoporphyrin (SnPP)IX for 1 h, and finally stimulated with TNF-α for 24 h (protein and cell adhesion) or 4 h (messenger (m)RNA). (E) Cells were transfected with scrambled (Scrb) or HO-1 small interfering RNA (siRNA), incubated with MVS (30 μM) for 1 or 6 h, and then incubated with TNF-α (15 ng/mL) for 24 h. (B) The adhesion of THP-1 cells (a human monocytic leukemia cell line) was measured. (C–E) The levels of ICAM-1, HO-1, and β-actin protein and mRNA were determined by Western blot and real-time PCR, respectively. (F) Cells were incubated with 0.5% dimethyl sulfoxide (DMSO) (control), or MVS (3, 10, and 30 μM) for 24 h and cell viability was determined using a 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay kit. Data are expressed as mean ± standard error of the mean (SEM) from five independent experiments (n = 5). ^#P < 0.01 as compared to (A) cells exposed to vehicle alone, or (B–E) significantly different as indicated.