Gene interactions and pathways from curated databases and text-mining
Kidney Int 2005, PMID: 16164642

VEGF regulation of endothelial nitric oxide synthase in glomerular endothelial cells.

Feliers, Denis; Chen, Xiaoyan; Akis, Nese; Choudhury, Goutam Ghosh; Madaio, Michael; Kasinath, Balakuntalam S

BACKGROUND

Vascular endothelial growth factor (VEGF) regulation of endothelial nitric oxide synthase (eNOS) and signaling pathways involved have not been well studied in glomerular endothelial cells (GENCs).

METHODS

GENCs grown from tsA58 Immortomice were used. Immunoblotting and in-cell Western blot analysis were employed to assess changes in VEGF receptor signaling pathway and eNOS phosphorylation of ser1177. Immunokinase assay and immunoblotting with phosphospecific antibodies were performed to assess activity of kinases.

RESULTS

VEGF rapidly induced tyrosine phosphorylation of type 1 and type 2 VEGF receptors. Physical association between VEGF-receptor 2 (VEGF-R2) and insulin receptor substrate (IRS-1) and phosphatidylinositol 3'-kinase (PI3K) was induced by VEGF, which augmented PI3K activity in VEGF-R2 immunoprecipitates. VEGF stimulated Akt phosphorylation in a PI3K-dependent manner. VEGF increased eNOS phosphorylation on Ser1177. Activation of eNOS was associated with nitric oxide generation as measured by medium nitrite content. Signaling mechanisms involved in VEGF stimulation of eNOS were explored. VEGF-induced eNOS phosphorylation was abolished by SU1498, a VEGF-R2 inhibitor, LY294002, a PI3K inhibitor, and infection of cells with an adenovirus carrying a dominant negative-mutant of Akt, demonstrating the requirement of the VEGF-R2/IRS-1/PI3K/Akt axis for activation of eNOS. VEGF also activated extracellular signal-regulated protein kinase (ERK) in a time-dependent manner; and VEGF-stimulated eNOS phosphorylation on Ser1177 was prevented by PD098059, an upstream inhibitor of ERK, demonstrating that ERK was involved in VEGF regulation of eNOS. ERK phosphorylation was abolished by LY294002, suggesting ERK was downstream of PI3K in VEGF-treated GENC.

CONCLUSIONS

Our data demonstrate that in GENC, VEGF stimulates VEGF-R2/IRS-1/PI3K/Akt axis to regulate eNOS phosphorylation on Ser1177 in conjunction with the ERK signaling pathway.

Diseases/Pathways annotated by Medline MESH: MAP Kinase Signaling System
Document information provided by NCBI PubMed

Text Mining Data

nitric oxide synthase — VEGF: " VEGF regulation of endothelial nitric oxide synthase in glomerular endothelial cells "

Akt → VEGF: " VEGF stimulated Akt phosphorylation in a PI3K dependent manner "

Akt — PI3K: " VEGF stimulated Akt phosphorylation in a PI3K dependent manner "

eNOS → VEGF: " VEGF increased eNOS phosphorylation on Ser1177 "

eNOS → VEGF: " VEGF induced eNOS phosphorylation was abolished by SU1498, a VEGF-R2 inhibitor, LY294002, a PI3K inhibitor, and infection of cells with an adenovirus carrying a dominant negative-mutant of Akt, demonstrating the requirement of the VEGF-R2/IRS-1/PI3K/Akt axis for activation of eNOS "

eNOS ⊣ VEGF: " VEGF also activated extracellular signal regulated protein kinase ( ERK ) in a time dependent manner ; and VEGF stimulated eNOS phosphorylation on Ser1177 was prevented by PD098059, an upstream inhibitor of ERK, demonstrating that ERK was involved in VEGF regulation of eNOS "

VEGF → ERK: " VEGF also activated extracellular signal regulated protein kinase ( ERK ) in a time dependent manner ; and VEGF stimulated eNOS phosphorylation on Ser1177 was prevented by PD098059, an upstream inhibitor of ERK, demonstrating that ERK was involved in VEGF regulation of eNOS "

eNOS → ERK: " VEGF also activated extracellular signal regulated protein kinase ( ERK ) in a time dependent manner ; and VEGF stimulated eNOS phosphorylation on Ser1177 was prevented by PD098059, an upstream inhibitor of ERK, demonstrating that ERK was involved in VEGF regulation of eNOS "

Manually curated Databases

No curated data.