(A) Schematic of in vitro EC functional assays. (B) Representative images of the EC migration assay using cultured bEND cells with or without TAN-derived supernatant (1:1 PMN/EC ratio) or rOPN, rVEGF treatment with or without specific antibody inhibition. Scale bar: 75 μm. (C) Quantification of EC migration (relative to serum-free condition) following coincubation with TAN-conditioned media, with or without antibody-mediated inhibition of OPN (6 μg/mL) and MMP14 (10 μg/mL). (D) Representative images of EC tube formation assay using cultured bEND cells with or without TAN-derived supernatant treatment (1:3 PMN/EC ratio), or rMMP14 with the indicated antibody inhibition. Scale bar: 10μm. (E) Quantification of formed tube numbers per FOVs upon coincubation with TAN-conditioned media, with or without antibody-mediated inhibition of OPN (6 μg/mL) or MMP14 (10 μg/mL). (F) Dose-response curves of cultured murine bENDs treated with rMMP14 with or without MMP14 inhibition. (G) Dose-response curves of cultured HUVECs following stimulation with catalytic domain (CD) or full-length (FL) rMMP14 (0.01–20 μg/mL), with or without Ab-inhibition of MMP14 (10 μg/mL). For tube formation and EC migration, images are representative of n = 2 independent repeats with TAN supernatants isolated from 3 mice for each performed in duplicates. For recombinant protein, n = 3 independent repeats performed in triplicates. For all quantifications, 15–20 FOVs were analyzed for each condition. For EC transmigration assay, 2-sided student’s t test was performed to compare treatments with serum-free condition. ****P < 0.0001, ^####P < 0.0001, MMP14 blockade versus nonblocking conditions. For tube formation assays in bEND or HUVEC cells, 1-way ANOVA was performed comparing Ab-blockade versus control conditions and between different concentrations of recombinant proteins. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, between treatment conditions. ^§§P < 0.01, ^§§§§P < 0.0001, selected dose(s) relative to the minimal rMMP14 dose of 0.01 μg/mL.