Figure 3.

Phospho-Smad2 is induced in TSP-1^−/− animals treated with bleomycin, which is accompanied by increased expression of connective tissue growth factor (CTGF). (A) Real-time PCR for CTGF expression. RNA was isolated from lung tissue and subjected to real-time PCR analysis, using SYBR Green. The relative copy number ± SEM, compared with GAPDH for CTGF, is shown. CTGF mRNA expression is increased in TSP-1–deficient mice. (B) Western blot for endogenous Smad activity after bleomycin challenge in TSP-1^−/− or WT murine lungs after bleomycin challenge. Lungs were homogenized to obtain protein from WT or TSP-1^−/− mice treated with either PBS or bleomycin. Equal concentrations of protein were subjected to Western blot analysis for phospho-Smad2, or total Smad2/3. (C) Densitometry for Smad activity. Western blots for phospho-Smad2 and Smad2/3 were quantitated by densitometry to average numbers of pixels for untreated WT mice. Shown is the average ratio ± SD. For the overall F-test, the P value was 0.031. All comparison P values were greater than the F-test P value.