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Netrin‐1 induces angiogenesis via a DCC dependent ERK1/2‐eNOS feed‐forward mechanism
Author(s) -
Cai Hua “Linda”,
Nguyen Andrew
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a715-a
Subject(s) - enos , netrin , angiogenesis , phosphorylation , microbiology and biotechnology , small interfering rna , chemistry , biology , cancer research , nitric oxide , axon guidance , endocrinology , biochemistry , nitric oxide synthase , transfection , axon , gene
Netrin‐1 is an axon guiding molecule that is critical for neuronal development. Because formation of vascular network shares many similarities with neuronal pathfinding, the present study examined whether and how netrin‐1 stimulates angiogenic response of endothelial cells. Exposure of aortic endothelial cells to netrin‐1 produced a potent, dose‐dependent increase in nitric oxide (NO) production, detected using an electron spin resonance spectrophotometer. Netrin‐1‐dependent angiogenic response, assessed by wound repair and aortic capillary outgrowth assays, was completely attenuated by scavenging NO with PTIO. Furthermore, netrin‐1 stimulated NO production was inhibited by antibody neutralizing the receptor deleted in colorectal cancer (DCC). Western blotting and antibody clearance experiment confirmed existence of DCC in endothelial cells. In addition, blockade of MEK1/2 pathway with PD98059, U0126 or specific siRNAs abolished netrin‐1 induced NO production and endothelial cell proliferation and migration, implying a critical role of ERK1/2 in eNOS activation by netrin‐1. Interestingly, scavenging NO with PTIO inhibited ERK1/2 phosphorylation, indicating a feed‐forward mechanism. Netrin‐1 induced a time‐dependent phosphorylation of eNOS at serine 1179 and 116 residues, and a rapid dephosphorylation of eNOS at threonine 495. However only serine 1179 phosphorylation was attenuated by U0126 and PTIO. These data for the first time characterized a novel mechanism whereby netrin‐1 promotes angiogenic response of endothelial cells. It is a DCC‐dependent ERK1/2‐eNOS feed‐forward cycle enabling sustained increase in endothelial NO production. This work is supported by an American Heart Association Grant (0435189N), an American Diabetes Association grant (7‐04‐RA‐16) and NIH Grants HL077440 and HL081571 (all to H Cai).