4-Hydroxynonenal Contributes to Angiogenesis through a Redox-Dependent Sphingolipid Pathway: Prevention by Hydralazine Derivatives

Figure 2

Dual effect of 4-HNE on neocapillary formation by HMEC-1. (a) Dose-response effect of 4-HNE on capillary tubes formed by HMEC-1. Cells were grown on Matrigel in MCDB131 culture medium supplemented with 0.1% FBS and PBS (negative control) or 4-HNE (in PBS) varying from 0.1 to 20 µM. After 18 h incubation, the cells were stained with calcein (1 μmol/1, 30 min) and photographed (Nikon Coolpix 995 camera) under a fluorescence microscope. Tube formation was expressed as linked cells per 100 cells. Results are means ± SEM of 6 to 8 experiments. Right panel, representative pictures of the experiments. ; ns: not significant. (b) Live-dead experiment on HMEC-1 stimulated by increasing 4-HNE concentrations and performed using the fluorescent DNA probes, permeant green Syto13 (0.6 µM) and nonpermeant red propidium iodide (1 µM). The results are expressed as the number (%) of living, apoptotic, or necrotic cells versus total cells. Right panels, representative pictures of fluorescence microscopy of HMEC-1, incubated for 18 h without (control) or with 4-HNE 1 µM or 20 µM. Means ± SEM of 3 experiments. ; ns: not significant.

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