Figure 1.

Electroporation-mediated SP-B gene transfer in compound SP-B mice 4 days after gene transfer and removal of doxycycline. (a) Western blots of SP-B protein expression. Compound SP-B transgenic mice (n = 5) were either maintained on doxycycline (+Dox) or were taken off doxycycline and 100 µg of each plasmid in 50 µl of 10 mM Tris, pH 8/1 mM EDTA/140 mM NaCl were delivered to the lungs by aspiration and electroporation using eight square wave pulses of 10 ms duration at a field strength of 200 V/cm as described in Materials and Methods. Four days later, lungs were removed from animals and a portion of the lungs was used for preparation of lysates for protein analysis by SDS-PAGE and Western blot using antibodies against mature SP-B. Blots were also reacted with antibodies against GAPDH to ensure appropriate loading. (b) Normalized densitometry of Western blot data. Intensities (mean ± st. dev.) of 18 kdal SP-B reactive bands from A were normalized to GAPDH expression. a, P < 0.005 compared to all other groups; b, P < 0.05 compared to No DNA group; c, P < 0.005 compared to No DNA group; and d, P < 0.005 compared to pcDNA3, by one-way ANOVA and post hoc Tukey multiple comparisons test