title: Nitric-oxide synthase trafficking inducer is a pleiotropic regulator of endothelial cell function and signaling.
abstract: Endothelial nitric-oxide synthase (eNOS) and its bioactive product, nitric oxide (NO), mediate many endothelial cell functions, including angiogenesis and vascular permeability. For example, vascular endothelial growth factor (VEGF)-mediated angiogenesis is inhibited upon reduction of NO bioactivity bothin vitroandin vivoMoreover, genetic disruption or pharmacological inhibition of eNOS attenuates angiogenesis during tissue repair, resulting in delayed wound closure. These observations emphasize that eNOS-derived NO can promote angiogenesis. Intriguingly, eNOS activity is regulated by nitric-oxide synthase trafficking inducer (NOSTRIN), which sequesters eNOS, thereby attenuating NO production. This has prompted significant interest in NOSTRIN's function in endothelial cells. We show here that NOSTRIN affects the functional transcriptome of endothelial cells by down-regulating several genes important for invasion and angiogenesis. Interestingly, the effects of NOSTRIN on endothelial gene expression were independent of eNOS activity. NOSTRIN also affected the expression of secreted cytokines involved in inflammatory responses, and ectopic NOSTRIN overexpression functionally restricted endothelial cell proliferation, invasion, adhesion, and VEGF-induced capillary tube formation. Furthermore, NOSTRIN interacted directly with TNF receptor-associated factor 6 (TRAF6), leading to the suppression of NFκB activity and inhibition of AKT activation via phosphorylation. Interestingly, TNF-α-induced NFκB pathway activation was reversed by NOSTRIN. We found that the SH3 domain of NOSTRIN is involved in the NOSTRIN-TRAF6 interaction and is required for NOSTRIN-induced down-regulation of endothelial cell proteins. These results have broad biological implications, as aberrant NOSTRIN expression leading to deactivation of the NFκB pathway, in turn triggering an anti-angiogenic cascade, might inhibit tumorigenesis and cancer progression.
authors.affiliation: From the Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, Kolkata 700032, West Bengal, India.
authors.forename: Shreeta
authors.identifier: 0000-0003-0911-2466
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: From the Division of Cell Biology and Physiology, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Chemical Biology, Kolkata 700032, West Bengal, India rupasri@iicb.res.in.
authors.forename: Rupasri
authors.identifier: 0000-0002-6016-6278
authors.initials: R
authors.lastname: Ain
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D020533:Angiogenesis Inhibitors / Q000737:chemistry; D000818:Animals; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018450:Disease Progression; D015536:Down-Regulation; D015971:Gene Expression Regulation, Enzymologic; D007249:Inflammation; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000378:metabolism; D009389:Neovascularization, Pathologic; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D000067996:RAW 264.7 Cells; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D020533:Angiogenesis Inhibitors; D016207:Cytokines; D004268:DNA-Binding Proteins; D016328:NF-kappa B; C495611:Nostrin protein, mouse; D034741:RNA, Small Interfering; D048029:TNF Receptor-Associated Factor 6; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496315:Nos3 protein, mouse
keywords: TNF receptor-associated factor (TRAF); angiogenesis; endothelial cell; invasion; nitric-oxide synthase