Figure 7.

Fibronectin proteolytic peptides in conditioned media do not induce fibroblast apoptosis. IMR-90 fibroblasts were treated with/without plasminogen (50 μg/ml) or TGF-β1 (2 ng/ml) for 18 hours. (A) Cell culture supernatants were assessed for fibronectin degradation peptides by Western immunoblotting. (B and C) α2-antiplasmin was added to the culture supernatants to neutralize residual plasmin activity. This conditioned media was then used to treat growth-arrested IMR-90 fibroblasts pre-treated with suramin (300 μM). After 18 hours, apoptosis was assessed by (B) Western immunoblotting for cleaved caspase 3 or by (C) ELISA for ssDNA.