Fig. 4.

Effects of lipid raft inhibitors on ERK phosphorylation and SP-C mRNA expression. A: E19 monolayers were incubated (or not) with the lipid raft disruptor cyclodextrin (10 mmol/l) and then exposed to 5% cyclic stretch for 15 min. Proteins were collected and processed to detect ERK activation [phosphorylated ERK (p-ERK)] by Western blotting. Blots were stripped and reprobed with total ERK (t-ERK) to control for protein loading. Blots represent results from 3 separate experiments. B: E19 type II cells were plated on Silastic membranes and maintained in culture overnight. On the next day, monolayers were preincubated (or not) with a cholesterol-chelating agent [methyl-β-cyclodextrin (10 mmol/l) or nystatin (1 μg/ml)] for 1 h and then subjected to 5% cyclic strain for 16 h. SP-C mRNA expression was analyzed by Northern blotting. Top blot represents results from 2 independent experiments. Bottom blot shows 18S rRNA to control for sample loading and RNA integrity.