Figure 8.

Metalloproteinase-mediated shedding of VE-cadherin in apoptotic HUVEC. HUVEC were cultured without growth factors for 8 h in the presence or absence of 50 mM of a metalloproteinase inhibitor, TAPI, and viable (V) and apoptotic (A) cells and supernatants (sup) were harvested separately and analyzed by SDS-PAGE and Western blotting with an antibody to (a) VE-cadherin or (b) β-catenin (^571–781 C). The relative levels of native VE-cadherin and fragment A increase in TAPI-treated cells, but TAPI does not prevent formation of fragment A. However, the soluble VE-cadherin fragment (B) is only detectable in the absence of TAPI but not in its presence, consistent with VE-cadherin shedding during HUVEC apoptosis mediated by a metalloproteinase.