Effects of different arginine concentrations on angiogenic protein production induced by HeLa cells

This in vitro study investigated the effects of different arginine (Arg) concentrations on angiogenic protein expressions of HeLa cells and endothelial cells (ECs) after stimulation. In addition, an inducible nitric oxide (iNO) synthase inhibitor (1400W) was used to investigate the possible role of iNO in angiogenesis.

Endothelial cells and HeLa cells were treated with different concentrations of Arg and 1400W: Arg 0, 50, 100, and 1000 micromol/L; Arg 100 micromol/L+1400W 10 micromol/L; and Arg 1000 micromol/L+1400W 10 micromol/L for 24 h. Then, ECs and HeLa cells were cocultured for 2 h, and the supernatant in the transwell was collected for analysis of angiogenic protein secreted. The expression of CD51/CD61 by ECs was also analyzed.

The productions of vascular endothelial growth factor, basic fibroblast growth factor, prostaglandin E(2), and matrix metalloproteinase-2 were higher with Arg 100 and 1000 micromol/L than with Arg 0 and 50 micromol/L Arg, and this was consistent with the expression of CD51/CD61 by ECs. Inhibition of iNO production resulted in lower angiogenic protein expressions comparable with groups with low Arg administration.

The findings of this study suggest that Arg administration at levels similar to or higher than physiologic concentrations enhance the production of angiogenic protein and iNO may partly play a role in promoting angiogenesis in the presence of HeLa cells.