Nitric oxide modulates hepatocyte growth factor/scatter factor-induced angiogenesis.
OBJECTIVE
There is limited knowledge about potential therapeutic targets in Hepatocyte growth factor/scatter factor (HGF)-induced pathophysiological angiogenesis. Recent candidates have included phosphatidylinositol-3-kinase, which is an upstream activator for endothelial nitric oxide (NO) synthase (NOS III). The current study is the first to evaluate the possible involvement of NOS-NO cascade in HGF-induced angiogenesis.


RESULTS
NOS III inhibitors blocked the HGF-induced functional neovascularization in vivo, as quantified using vessel counts, 133Xe-clearance, and immunohistology. This was reversed by L-arginine. Western blot analysis of HGF-treated cells also revealed a temporal increase in HGF-induced phosphorylation. In a deconstructional approach, HGF induced the proliferation and chemokinesis of human endothelial cells. These phenotypic effects were inhibited by NOS inhibitors, L-NAME and L-NIO, and the NO scavenger, carboxy PTIO, but unaltered by 1400W, a NOS II inhibitor. This inhibition was reversed by spermine NONOate, a NO donor, which independently exerted a biphasic effect on endothelial cell proliferation. The modulation of NO did not alter HGF-induced chemoinvasion of endothelial cells, while spermine-NONOate destabilized HGF-induced tubulogenesis, suggesting that a single assay is not sufficient for predicting the final phenotypic outcome on angiogenesis.


CONCLUSIONS
The study is the first to demonstrate that the NOS III nitric oxide is a key signal cascade in HGF-induced angiogenesis, and represents a promising target for the clinical management of pathological conditions characterized by overt HGF signaling.
Sengupta
Shiladitya
S
Department of Pharmacology, Angiogenesis Laboratory, Babraham Institute, Cambridge, UK. shiladit@MIT.edu
Sellers
Lynda A
LA
Gherardi
Ermanno
E
Sasisekharan
Ram
R
Fan
Tai-Ping D
TP
D000818:Animals; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D017228:Hepatocyte Growth Factor / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D017228:Hepatocyte Growth Factor; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D019331:NG-Nitroarginine Methyl Ester