Genomes and Genes
Perinatal regulation of endothelial NOS
Principal Investigator: Stephen Black
Abstract: The overall goal of these continuing studies is to understand how endothelial nitric oxide synthase (eNOS) signaling is regulated in the pulmonary system with emphasis on its role in the perinatal period. We have recently demonstrated in vivo, that endothelin-1 (ET-1) acutely decreases nitric oxide (NO) generation in a mechanism that involves alterations in endothelial NO synthase (eNOS) activity, and that these interactions mediate dynamic changes in vascular tone following acute, surgically-induced, changes in PBF. Acute changes in pulmonary blood flow (PBF) in the perinatal period are an integral part of surgical repair of many congenital heart defects (CHD). In patients with single ventricle anatomy and physiology, the post-operative balance of blood flow to the lungs and body is often dictated by the resistances of the respective vascular beds. In fact, post-operatively the dynamic changes in vascular resistance can lead to significant morbidity and mortality, and much of our therapies are focused on altering pulmonary vascular resistance in attempt to optimize cardiac output while maintaining enough pulmonary blood flow to ensure adequate systemic oxygenation. Our new in vitro data indicate that ET-1-mediated activation of PKCd activity blocks the shear mediated increase in NO generation. Our preliminary data have also identified a previously undescribed mechanism by which ET-1 inhibits eNOS activity: decreasing ser1177 phosphorylation secondary to a catalase-mediated decrease in hydrogen peroxide (H2O2) that is regulated by PKCd activation. Based on these data, we hypothesize that alterations in NO-ET-1 interactions mediate the dynamic changes in pulmonary vascular resistance immediately following surgically induced changes in PBF in children with CHD. Further, we hypothesize that ET-1, via ETB receptor signaling, decreases NO signaling secondary to increased PKCd activity, thereby limiting the increases in PBF following surgery. Thus, in this competitive renewal, we will utilize an integrated physiologic, biochemical, cellular, and molecular approach, to investigate this hypothesis and its mechanisms. A better understanding of these mechanisms may improve peri- operative treatment strategies and reduce both short and long-term morbidity and mortality in children with CHD. PUBLIC HEALTH RELEVANCE: Acute changes in pulmonary blood flow (PBF) are an integral part of surgical repair of many congenital heart defects and in patients with single ventricle anatomy and physiology, the resistances of the respective vascular beds often dictate the post- operative balance of blood flow to the lungs and body. Normal pulmonary vascular tone is regulated by a complex interaction of vasoactive substances, such as NO and ET-1, that are produced locally by the vascular endothelium and we propose to investigate the role of NO, ET-1, and their interactions, in mediated the dynamic changes in vascular tone associated with acute changes in PBF. A better understanding of these mechanisms may improve peri-operative treatment strategies for children with congenital heart disease and have important clinical implications for thoracic surgery, transplantation, as well as systemic vascular biological disorders.
Funding Period: ----------------1998 - ---------------2011-
more information: NIH RePORT
- Identification of the tyrosine nitration sites in human endothelial nitric oxide synthase by liquid chromatography-mass spectrometryMichael A Zickus
Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, USA
Eur J Mass Spectrom (Chichester, Eng) 14:239-47. 2008....
- Endothelin-1 stimulates catalase activity through the PKCδ-mediated phosphorylation of serine 167Ruslan Rafikov
Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA
Free Radic Biol Med 67:255-64. 2014..In conclusion, this is the first report indicating that the phosphorylation of catalase regulates its multimeric structure and activity. ..
- Reactive oxygen species in pulmonary vascular remodelingSaurabh Aggarwal
Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia, USA
Compr Physiol 3:1011-34. 2013..This review will focus on the ROS generation systems, scavenger antioxidants, and oxidative stress associated alterations in vascular remodeling in pulmonary hypertension...
- Chronic inhibition of PPAR-γ signaling induces endothelial dysfunction in the juvenile lambShruti Sharma
Vascular Biology Center, Georgia Health Sciences University, 1459 Laney Walker Blvd, CB3210B, Augusta, GA 30912, USA
Pulm Pharmacol Ther 26:271-80. 2013..We conclude that loss of PPAR-γ signaling is sufficient to induce endothelial dysfunction confirming its important role in maintaining a healthy vasculature...
- Increased NADPH oxidase-derived superoxide is involved in the neuronal cell death induced by hypoxia-ischemia in neonatal hippocampal slice culturesQing Lu
Vascular Biology Center, Georgia Health Sciences University, Augusta, GA 30912, USA
Free Radic Biol Med 53:1139-51. 2012....
- Preserving mitochondrial function prevents the proteasomal degradation of GTP cyclohydrolase IShruti Sharma
Program in Pulmonary Vascular Disease, Vascular Biology Center, Georgia Health Sciences University, Augusta, GA 30912, USA
Free Radic Biol Med 53:216-29. 2012..Thus, we conclude that L-carnitine may have a therapeutic potential in the treatment of pulmonary hypertension in children with CHD with increased pulmonary blood flow...
- Oxidative stress and the development of endothelial dysfunction in congenital heart disease with increased pulmonary blood flow: lessons from the neonatal lambSaurabh Aggarwal
Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, GA 30912, USA
Trends Cardiovasc Med 20:238-46. 2010....
- Purification and functional analysis of protein kinase G-1α using a bacterial expression systemSaurabh Aggarwal
Pulmonary Disease Program, Vascular Biology Center, Medical College of Georgia, Augusta, GA, United States
Protein Expr Purif 79:271-6. 2011....
- Attenuated vasodilatation in lambs with endogenous and exogenous activation of cGMP signaling: role of protein kinase G nitrationSaurabh Aggarwal
Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia 30912, USA
J Cell Physiol 226:3104-13. 2011..Together our data reveal that vascular dysfunction can occur, despite elevated levels of cGMP, due to PKG-1α nitration and subsequent attenuation of activity...
- Mechanisms of nitric oxide synthase uncoupling in endotoxin-induced acute lung injury: role of asymmetric dimethylarginineShruti Sharma
Medical College of Georgia, Augusta, GA 30912, USA
Vascul Pharmacol 52:182-90. 2010..In conclusion, this is the first study that suggests a role of the ADMA/DDAH pathway during the development of ALI in mice and that ADMA may be a novel therapeutic biomarker to ascertain the risk for development of ALI...
- Alterations in lung arginine metabolism in lambs with pulmonary hypertension associated with increased pulmonary blood flowShruti Sharma
Vascular Biology Center, 1459 Laney Walker Boulevard, CB3201B, Medical College of Georgia, Augusta, GA 30912, USA
Vascul Pharmacol 51:359-64. 2009....
- Elevated zinc induces endothelial apoptosis via disruption of glutathione metabolism: role of the ADP translocatorDean A Wiseman
Vascular Biology Center, Medical College of Georgia, 1459 Laney Walker Blvd CB 3210, Augusta, GA 30912 2500, USA
Biometals 23:19-30. 2010..These pathways could represent novel therapeutic targets during acute oxidative or nitrosative stress in cells and tissues...
- Sox18 preserves the pulmonary endothelial barrier under conditions of increased shear stressChristine M Gross
Pulmonary Disease Program Vascular Biology Center, Georgia Regents University, Augusta, Georgia
J Cell Physiol 229:1802-16. 2014..In conclusion, these novel findings suggest that increased laminar flow protects endothelial barrier function via Sox18 dependent up-regulation of Claudin-5 expression...
- Endothelin-1 impairs nitric oxide signaling in endothelial cells through a protein kinase Cdelta-dependent activation of STAT3 and decreased endothelial nitric oxide synthase expressionNeetu Sud
Program in Pulmonary Vascular Disease, Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912, USA
DNA Cell Biol 28:543-53. 2009..This in turn decreases eNOS promoter activity, protein levels, and NO production. Thus, ET-1 can reduce eNOS expression and NO generation in fetal pulmonary artery endothelial cells through PKCdelta-mediated activation of STAT3...
- Hydrogen peroxide decreases endothelial nitric oxide synthase promoter activity through the inhibition of Sp1 activitySanjiv Kumar
Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912, USA
DNA Cell Biol 28:119-29. 2009..Together, these data suggest that the inhibition of Sp1 activity, possibly through loss of zinc in the protein, plays a role in the H(2)O(2)-induced inhibition of eNOS promoter activity...