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.
|Marsboom, Glenn; Rehman, Jalees (2018) Hypoxia Signaling in Vascular Homeostasis. Physiology (Bethesda) 33:328-337|
|Lv, Yang; Kim, Kyungho; Sheng, Yue et al. (2018) YAP Controls Endothelial Activation and Vascular Inflammation Through TRAF6. Circ Res 123:43-56|
|Christoforidis, Theodore; Driver, Tom G; Rehman, Jalees et al. (2018) Generation of controllable gaseous H2S concentrations using microfluidics. RSC Adv 8:4078-4083|
|Di, Anke; Xiong, Shiqin; Ye, Zhiming et al. (2018) The TWIK2 Potassium Efflux Channel in Macrophages Mediates NLRP3 Inflammasome-Induced Inflammation. Immunity 49:56-65.e4|
|Chen, Zhenlong; D S Oliveira, Suellen; Zimnicka, Adriana M et al. (2018) Reciprocal regulation of eNOS and caveolin-1 functions in endothelial cells. Mol Biol Cell 29:1190-1202|
|Le Master, Elizabeth; Huang, Ru-Ting; Zhang, Chongxu et al. (2018) Proatherogenic Flow Increases Endothelial Stiffness via Enhanced CD36-Mediated Uptake of Oxidized Low-Density Lipoproteins. Arterioscler Thromb Vasc Biol 38:64-75|
|Komarova, Yulia; Kruse, Kevin J; Mehta, Dolly et al. (2017) Response by Komarova et al to Letter Regarding Article, ""Protein Interactions at Endothelial Junctions and Signaling Mechanisms Regulating Endothelial Permeability"". Circ Res 120:e28|
|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|
|Soni, Dheeraj; Regmi, Sushil C; Wang, Dong-Mei et al. (2017) Pyk2 phosphorylation of VE-PTP downstream of STIM1-induced Ca2+ entry regulates disassembly of adherens junctions. Am J Physiol Lung Cell Mol Physiol 312:L1003-L1017|
|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|
Showing the most recent 10 out of 200 publications