Fig 1: SMAD2 degradation under hypoxia is facilitated by calpain. a-f Macrophages were stimulated with TGFß under normoxia vs. hypoxia for 8 h in the presence of bafilomycin a, b, MG132 c, d, or lactacystin e, f. 2 h after TGFß, inhibitors were added and incubations went on for 6 h. Western blot analysis and statistical evaluation is presented. g mRNA expression of the calpain regulatory subunit (CAPNS1) was analyzed by quantitative PCR in macrophages exposed for 8 h to TGFß under normoxia (nor) vs. hypoxia (hy). h Western blot analysis of the calpain regulatory subunit after exposure to TGFß and/or hypoxia for 8 h. i mRNA expression of the calpain 1 catalytic subunit (CAPN1) was analyzed by quantitative PCR in macrophages exposed for 8 h to TGFß under normoxia (nor) vs. hypoxia (hy). j Proteolytic cleavage of CAPN1 under TGFß/hypoxia was followed in macrophages by Western blot analysis after 8 h. k Macrophages were exposed to the calpain inhibitor 1 (CPI) to follow SMAD2 degradation after stimulating cells for 8 h with TGFß under normoxia vs. hypoxia