Ceramide is a lipid-derived second messenger that suppresses vascular smooth muscle (VSM) cell mitogenesis in vitro and in vivo. Multiple laboratories, including our own, have identified protein kinase C zeta (PKCzeta) as a target of ceramide. We have published data demonstrating that ceramide-activated PKCzeta is necessary for VSM cell growth arrest. Two signaling pathways have been identified that contribute to the anti-mitogenic actions of ceramide. Ceramide directly activates PKCzeta, to 1.) induce SAPK signal complex formation;and 2.) inhibit AKT1 signaling cascades. Elucidation of the biophysical and biochemical mechanisms by which ceramide activates PKCzeta is the focus of this new proposal. It is now hypothesized that ceramide stimulates PKCzeta;activity within discrete lipid microdomains or rafts. We will test this hypothesis in the following Specific Aims.
In Specific Aim 1, we will identify ceramide-enriched lipid rafts as the site at which PKCzeta, is phosphorylated and optimally activated by upstream kinases.
In Specific Aim 2, we will characterize and validate ceramide-binding domains or clefts on PKCzeta. These studies will elucidate the biophysical and biochemical mechanisms by which inflammatory cytokine receptor-induced ceramide formation limits cellular proliferation in models of inflammatory vascular diseases. The long-term innovation of these studies is the clinical potential of direct delivery of ceramide analogues to the site of dysregulated VSM growth observed after angioplasty and stent placement. Additionally, this proposal holds the promise of defining lipidomimetics suitable as therapeutics or screening tools for further drug discovery.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL076789-05
Application #
7842656
Study Section
Membrane Biology and Protein Processing (MBPP)
Program Officer
Hasan, Ahmed AK
Project Start
2006-08-01
Project End
2012-05-31
Budget Start
2010-06-01
Budget End
2012-05-31
Support Year
5
Fiscal Year
2010
Total Cost
$354,341
Indirect Cost
Name
Pennsylvania State University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Hankins, Jody L; Ward, Katherine E; Linton, Sam S et al. (2013) Ceramide 1-phosphate mediates endothelial cell invasion via the annexin a2-p11 heterotetrameric protein complex. J Biol Chem 288:19726-38
Ryland, Lindsay K; Doshi, Ushma A; Shanmugavelandy, Sriram S et al. (2013) C6-ceramide nanoliposomes target the Warburg effect in chronic lymphocytic leukemia. PLoS One 8:e84648
O'Neill, Sean M; Yun, Jong K; Fox, Todd E et al. (2011) Transcriptional regulation of the human neutral ceramidase gene. Arch Biochem Biophys 511:21-30
Jiang, Yixing; DiVittore, Nicole A; Kaiser, James M et al. (2011) Combinatorial therapies improve the therapeutic efficacy of nanoliposomal ceramide for pancreatic cancer. Cancer Biol Ther 12:574-85
Heakal, Yasser; Woll, Matthew P; Fox, Todd et al. (2011) Neurotensin receptor-1 inducible palmitoylation is required for efficient receptor-mediated mitogenic-signaling within structured membrane microdomains. Cancer Biol Ther 12:427-35
O'Neill, Sean M; Houck, Kristy L; Yun, Jong K et al. (2011) AP-1 binding transcriptionally regulates human neutral ceramidase. Arch Biochem Biophys 511:31-9
Hankins, Jody L; Fox, Todd E; Barth, Brian M et al. (2011) Exogenous ceramide-1-phosphate reduces lipopolysaccharide (LPS)-mediated cytokine expression. J Biol Chem 286:44357-66
Tagaram, Hephzibah Rani S; Divittore, Nicole A; Barth, Brian M et al. (2011) Nanoliposomal ceramide prevents in vivo growth of hepatocellular carcinoma. Gut 60:695-701
Ganapathi, Sindura B; Fox, Todd E; Kester, Mark et al. (2010) Ceramide modulates HERG potassium channel gating by translocation into lipid rafts. Am J Physiol Cell Physiol 299:C74-86
Winter, Jeremiah N; Fox, Todd E; Kester, Mark et al. (2010) Phosphatidic acid mediates activation of mTORC1 through the ERK signaling pathway. Am J Physiol Cell Physiol 299:C335-44

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