Figure 3-6929.
Integrin-mediated activation of TGF-β by fetal tracheal fragments, fetal tracheal epithelial cells, and fibroblasts. TGF-β bioassay of active TGF-β produced by fetal tracheal fragments (A), fetal tracheal epithelial cells (B), and fetal tracheal fibroblasts (C–E). Fetal tracheal fragments were co-cultured with TGF-β reporter cells (TMLC), which stably express a portion of the plasminogen activator inhibitor-1 promoter driving the luciferase minigene, in the presence of no inhibitor (filled bar), anti-pan-TGF-β (open bar), anti-β8 (horizontal hatched bars), or anti-β6 (vertical hatched bars). The results are expressed in arbitrary luciferase units with the TMLC background subtracted. *P < 0.05, **P < 0.001. D: αvβ8-dependent activation of TGF-β3 in fetal tracheal fibroblasts. The assay was performed in the presence of no inhibitor (filled bar), anti-β8 (horizontal hatched bar), anti-TGF-β1 (diagonal hatched bars), or anti-TGF-β3 (crosshatched bars). E: Inhibition of TGF-β activation by the metalloprotease inhibitor GM6001, a pan-metalloprotease inhibitor, in the TGF-β bioassay. The assay was performed in the presence of no inhibitor (filled bar), anti-pan-TGF-β (open bar), anti-β8 (horizontal hatched bars), or GM6001 (vertical hatched bars). The results are presented as the percent inhibition of total TGF-β activation. *P < 0.05, **P < 0.001.