Figure 6.

RNAi-mediated gene silencing of SNAI1 protects against loss of the CIPs CD46 and CD55 in SAECs. A) SAECs were treated with or without TGF-β1 (10 ng/ml) for the indicated times. RNA lysates were used to synthesize cDNA, which was then subjected to quantitative reverse transcriptase PCR (qRT-PCR) for SNAI1 and normalized with GAPDH. Values represent means ± sem (n=3). *P < 0.05 vs. baseline; unpaired t test. B) SAECs were pretreated with p38MAPK inhibitor (p38 In; SB203580; 6 μM) for1 h and then treated with TGF-β1 (10 ng/ml) for 6 h or were not treated. SNAI1 was analyzed by qRT-PCR (endogenous control, GAPDH). Values represent means ± sem (n=3). *P < 0.05, **P < 0.01 vs. TGF-β1; 1-way ANOVA with Bonferroni post hoc test. C) SAECs were transfected with nontargeting or SNAI1-specific siRNA sequences for 24 h, followed by treatment with TGF-β1 (10 ng/ml) for 6 h, or were not treated. SNAI1 was analyzed by qRT-PCR (endogenous control, GAPDH). Values represent means ± sem (n=3–4). *P < 0.05, **P < 0.01 vs. TGF-β1; 1-way ANOVA with Bonferroni post hoc test. D) SAECs were transfected as in C, followed by treatment with TGF-β1 (10 ng/ml) for 48 h, or were not treated. Protein lysates were immunoblotted against Snail, CD46, CD55, and total/cleaved PARP (β-actin, loading control). Data are representative of analyses of cells from 3 independent donors.