The major source of """"""""high-output"""""""" nitric oxide (NO) during inflammation is inducible NO synthase (iNOS). Although iNOS is a transcriptionally-regulated generator of high NO, we have discovered a novel mode of post- translational, G protein coupled receptor (GPCR)-mediated activation of iNOS via ERK-dependent phosphorylation in endothelial cells. Post-translational activation of iNOS results in a further 3- to 5-fold increase in NO concentration over its already high basal amount. In Project 2, we will address the mechanisms by which iNOS phosphorylation leads to high output NO production and how this influences the lung endothelial barrier. We will test the hypotheses that (i) activation of the kinin GPCR, BI, induces ?-arrestin2 scaffolding of iNOS and ERK, which in turn phosphorylates and activates iNOS due to enhanced dimerization and isomerization by the prolyl isomerase Pin1, (ii) S-nitrosylation of ?-arrestin2 dissociates it from iNOS, resulting in dephosphorylation and inactivation ,and (iii) post-translationally activated iNOS-derived NO causes increased lung vascular permeability in the context of NADPH oxidase (NOX2) activation and peroxynitrite generation resulting in endocytosis of VE-cadherin and inactivation of p190RhoGAP. The signaling pathways mediating receptor-dependent post-translational activation of iNOS in pulmonary endothelial cells and its effects on pulmonary vascular permeability will be investigated using imaging, cell biology, biochemical, and physiological approaches. We will thereby establish the role of key signaling molecules ?-arrestin2 and Pin1 in mediating INOS activation and functions of ?-arrestin2, p190RhoGAP and VE-cadherin in mediating disruption of lung endothelial barrier function. The proposed studies we hope will provide novel therapeutic strategies to inhibit detrimental consequences of high concentrations of NO in inflammatory lung injury based on the deeper understanding of signaling pathways by which iNOS is activated secondary to its expression in the endothelium.
Nitric oxide is an important signaling molecule made by blood vessels and during infection or inflammation, high levels of this molecule can be generated to cause damage to the lung. The proposed studies will investigate mechanisms by which vascular endothelial cells generate high levels of nitric oxide and how this affects the permeability or leakiness of lung vessels. We hope our findings will provide novel therapeutic strategies to inhibit detrimental consequences of high nitric oxide in inflammatory lung injury.
|Jiang, Chunling; Liu, Zheng; Hu, Rong et al. (2017) Inactivation of Rab11a GTPase in Macrophages Facilitates Phagocytosis of Apoptotic Neutrophils. J Immunol 198:1660-1672|
|Mittal, Manish; Nepal, Saroj; Tsukasaki, Yoshikazu et al. (2017) Response by Mittal et al to Letter Regarding Article, ""Neutrophil Activation of Endothelial Cell-Expressed TRPM2 Mediates Transendothelial Neutrophil Migration and Vascular Injury"". Circ Res 121:e87|
|Oliveira, Suellen D S; Castellon, Maricela; Chen, Jiwang et al. (2017) Inflammation-induced caveolin-1 and BMPRII depletion promotes endothelial dysfunction and TGF-?-driven pulmonary vascular remodeling. Am J Physiol Lung Cell Mol Physiol 312:L760-L771|
|Potje, Simone R; Chen, Zhenlong; Oliveira, Suellen D'Arc S et al. (2017) Nitric oxide donor [Ru(terpy)(bdq)NO]3+ induces uncoupling and phosphorylation of endothelial nitric oxide synthase promoting oxidant production. Free Radic Biol Med 112:587-596|
|Gong, Haixia; Liu, Menglin; Klomp, Jeff et al. (2017) Method for Dual Viral Vector Mediated CRISPR-Cas9 Gene Disruption in Primary Human Endothelial Cells. Sci Rep 7:42127|
|Gu, Wei; Yao, Lun; Li, Lexing et al. (2017) ICAM-1 regulates macrophage polarization by suppressing MCP-1 expression via miR-124 upregulation. Oncotarget 8:111882-111901|
|Tsang, Kit Man; Hyun, James S; Cheng, Kwong Tai et al. (2017) Embryonic Stem Cell Differentiation to Functional Arterial Endothelial Cells through Sequential Activation of ETV2 and NOTCH1 Signaling by HIF1?. Stem Cell Reports 9:796-806|
|Park, Thomas J; Reznick, Jane; Peterson, Bethany L et al. (2017) Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat. Science 356:307-311|
|Yazbeck, Pascal; Tauseef, Mohammad; Kruse, Kevin et al. (2017) STIM1 Phosphorylation at Y361 Recruits Orai1 to STIM1 Puncta and Induces Ca2+ Entry. Sci Rep 7:42758|
|Marsboom, Glenn; Chen, Zhenlong; Yuan, Yang et al. (2017) Aberrant caveolin-1-mediated Smad signaling and proliferation identified by analysis of adenine 474 deletion mutation (c.474delA) in patient fibroblasts: a new perspective on the mechanism of pulmonary hypertension. Mol Biol Cell 28:1177-1185|
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