Recent studies have indicated that ceramide, a sphingolipid contributes to the detrimental effects of different factors such as TNF-alpha, Fas L and endostatin to produce endothelial dysfunction. However, the mechanisms responsible for the production and actions of ceramide in endothelial cells are still poorly understood. Recently, a novel mechanism involving membrane lipid rafts and their aggregation has been reported to participate in ceramide-mediated transmembrane and intracellular signaling. In this proposal, we hypothesize that ceramide production and lipid raft clustering aggregate different signaling molecules such as NADPH oxidase subunits to form a membrane signaling amplification platform and thereby contributes to the reduction of NO bioavailability and endothelial dysfunction induced by different injury factors. We will first demonstrate the formation of lipid raft platforms and associated aggregation of the receptors in response to Fas L or TNF-alpha in bovine coronary arterial endothelial cells using fluorescent and confocal microscopy and flotation of detergent resistant membranes. We will also determine the association of ceramide with lipid raft clustering and explore the mechanisms of ceramide production by selective inhibition of related enzymes or by silencing the genes coding these enzymes such as sphingomyelinases using siRNA. Then, we will determine whether lipid raft clustering co-aggregates and activates endothelial NADPH oxidase by confocal microscopy, enzyme kinetic analysis and subunit translocation detection. Finally, we will determine whether lipid raft clustering stimulates 02- production and thereby contributes to endothelial dysfunction associated with NO using fluorescence imaging analysis of NO or 02- in the intact endothelium of bovine coronary arteries. The results of these studies will clarify the role of lipid raft clustering and ceramide production in mediating the actions of Fas L and TNF-alpha and provide new insights into the mechanisms contributing to endothelial dysfunction under different pathological conditions such as ischemia/reperfusion, atherosclerosis and hypertension.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Cardiovascular and Renal Study Section (CVB)
Program Officer
Srinivas, Pothur R
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Virginia Commonwealth University
Schools of Medicine
United States
Zip Code
Li, Guangbi; Chen, Zhida; Bhat, Owais M et al. (2017) NLRP3 inflammasome as a novel target for docosahexaenoic acid metabolites to abrogate glomerular injury. J Lipid Res 58:1080-1090
Conley, Sabena M; Abais-Battad, Justine M; Yuan, Xinxu et al. (2017) Contribution of guanine nucleotide exchange factor Vav2 to NLRP3 inflammasome activation in mouse podocytes during hyperhomocysteinemia. Free Radic Biol Med 106:236-244
Koka, Saisudha; Xia, Min; Chen, Yang et al. (2017) Endothelial NLRP3 inflammasome activation and arterial neointima formation associated with acid sphingomyelinase during hypercholesterolemia. Redox Biol 13:336-344
Bao, Jun-Xiang; Zhang, Qin-Fang; Wang, Mi et al. (2017) Implication of CD38 gene in autophagic degradation of collagen I in mouse coronary arterial myocytes. Front Biosci (Landmark Ed) 22:558-569
Chen, Yang; Yuan, Ming; Xia, Min et al. (2016) Instant membrane resealing in nlrp3 inflammmasome activation of endothelial cells. Front Biosci (Landmark Ed) 21:635-50
Xia, Min; Abais, Justine M; Koka, Saisudha et al. (2016) Characterization and Activation of NLRP3 Inflammasomes in the Renal Medulla in Mice. Kidney Blood Press Res 41:208-21
Xu, Xiaoyang; Yuan, Xinxu; Li, Ningjun et al. (2016) Lysosomal cholesterol accumulation in macrophages leading to coronary atherosclerosis in CD38(-/-) mice. J Cell Mol Med 20:1001-13
Boini, Krishna M; Xia, Min; Koka, Saisudha et al. (2016) Instigation of NLRP3 inflammasome activation and glomerular injury in mice on the high fat diet: role of acid sphingomyelinase gene. Oncotarget 7:19031-44
Li, Guangbi; Xia, Min; Abais, Justine M et al. (2016) Protective Action of Anandamide and Its COX-2 Metabolite against l-Homocysteine-Induced NLRP3 Inflammasome Activation and Injury in Podocytes. J Pharmacol Exp Ther 358:61-70
Meng, Nan; Xia, Min; Lu, Ya-Qi et al. (2016) Activation of NLRP3 inflammasomes in mouse hepatic stellate cells during Schistosoma J. infection. Oncotarget 7:39316-39331

Showing the most recent 10 out of 83 publications