Fig. 5.
Effects of caveolin-1 small interference RNA (siRNA) on ERK phosphorylation and SP-C mRNA expression. A: E19 type II cells were transfected by electroporation, as described in materials and methods, with nontargeted siRNA or caveolin-1 siRNA at different concentrations. Two days later, proteins were collected and processed by Western blotting to detect caveolin-1 abundance. Blots were reprobed with GAPDH to control for protein loading. Blots represent results from 3 independent experiments. *P < 0.05 vs. nontargeted (Dunnett's test). B: E19 cells were transfected with nontargeted or caveolin-1 siRNA (2 μM) and then exposed to 5% cyclic stretch for 15 min. Proteins were collected and processed to detect ERK phosphorylation by Western blotting. Blots represent results from 3 independent experiments. Values, expressed as percent change from controls normalized to 100, are from 3 independent experiments. *P < 0.05 vs. nontargeted control; **P < 0.001 vs. nontargeted stretch. C: E19 type II cells were transfected by electroporation with nothing (pulse only), nontargeted siRNA, or caveolin-1 siRNA (2 μM). Total RNA was reverse-transcribed, and the cDNA product for SP-C was analyzed by quantitative RT-PCR using the ΔΔCT method for relative quantification. *P < 0.001 vs. respective controls; **P < 0.01 vs. pulse or nontargeted siRNA stretch (n = 4).