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VEGF Regulation of Endothelial Nitric Oxide Synthase in Glomerular Endothelial Cells       
Yazarlar (6)
Denis Feliers
Xiaoyan Chen
Prof. Dr. Neşe SANSA Prof. Dr. Neşe SANSA
Goutam Ghosh Choudhury
Michael Madaio
Balakuntalam S. Kasinath
Joe R. & Teresa Lozano Long School Of Medicine, Amerika Birleşik Devletleri
Devamını Göster
Özet
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. © 2005 by the International Society of Nephrology.
Anahtar Kelimeler
eNOS | Glomerular endothelial cells | Signal transduction | VEGF
Makale Türü Açık Erişim Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale
Dergi Adı Kidney International
Dergi ISSN 0085-2538 Wos Dergi Scopus Dergi
Dergi Tarandığı Indeksler SCI-Expanded
Dergi Grubu Q4
Makale Dili İngilizce
Basım Tarihi 01-2005
Cilt No 68
Sayı 4
Sayfalar 1648 / 1659
Doi Numarası 10.1111/j.1523-1755.2005.00575.x