Fig. 5

ELISA showed that extracellular MMP-2 of HUVEC decreases with prolonged exposure to H₂O₂ (A); Gelatin zymography indicated that H₂O₂ caused diminished activity of MMP-2 (B); Electron microscopy observed that the caveolae-1 on the surface of HUVEC were more accessible to the intracellular compartment under the treatment of H₂O₂, the yellow arrows indicated the caveolae-1 (C). Western-blot showed that the expression of phosphorylated caveolin-1 within HUVEC was upregulated in response to H₂O₂ (D). The addition of filipin-III resulted in downregulation of SPARC protein within HUVECs compared to H₂O₂-treated group and control (E)

HUVECs: human umbilical vein endothelial cells; ELISA: enzyme-linked immunosorbent assay; MMP-2: matrix metalloproteinase 2; SPARC: secreted acidic and cysteine-rich protein