Atherosclerosis is the major cause of morbidity and mortality in America. This disease process is defined by the formation of vascular lesions that contain activated macrophages (MO) and dysfunctional endothelial (EC) and smooth muscle cells (SMC). The unfolded protein response (UPR) has been implicated as a cellular process that is induced in atherosclerotic lesions, and in cultured cells (MO, EC and SMC) treated with known pro-atherogenic inducers. The primary aim of this grant will be to explore the function of a novel gene, CHAC1. This protein is specifically induced by UPR activation and is downstream ofthe ATF4-ATF3- CHOP cascade, an important pro-apoptotic pathway ofthe UPR. CHAC1 is a soluble cytosolic peptide, which induces apoptosis when over-expressed, and siRNA knockdown confirms a pro-apoptotic role for this gene. CHAC1 activates TNFRSF6B, a FASL decoy receptor, which functions to antagonize FASL-FAS induced apoptosis signaling. This pathway is of importance because FASL expressing cells can induce apoptosis of MO, EC or SMC, and this my exacerbate the progression of vascular disease. The proposal herein will define the function of CHAC1 at the molecular level, and characterize its contribution to apoptosis and the atherosclerotic disease process in MO, EC and SMC. The contribution of CHAC1 in CHOP and UPR induced apoptosis will be defined using established over-expression plasmids and siRNAs, generation of knockout cells, and assaying different components of putative signaling cascades. Direct binding partners of CHAC1 will also be explored using the TAP method, to define the molecular'^function ofthis gene. Candidates from TAP screening will be validated using co-immuno-precipitation. Based on candidates identified, pijtative functions ofthe chaC domain will be assayed, and targeted deletion and site directed mutagenesis used to define important regions of the protein. Finally, the use of mice that have the CHAC1 gene knocked out will be generated to explore the effects of CHAC1 genetic ablation in the development of atherosclerosis in a mouse disease model.

Agency
National Institute of Health (NIH)
Type
Research Transition Award (R00)
Project #
5R00HL094709-05
Application #
8656736
Study Section
No Study Section (in-house review) (NSS)
Program Officer
Olive, Michelle
Project Start
Project End
Budget Start
Budget End
Support Year
5
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Louisiana State Univ Hsc New Orleans
Department
Pharmacology
Type
Schools of Medicine
DUNS #
City
New Orleans
State
LA
Country
United States
Zip Code
70112
Delgado-Peraza, Francheska; Ahn, Kwang H; Nogueras-Ortiz, Carlos et al. (2016) Mechanisms of Biased β-Arrestin-Mediated Signaling Downstream from the Cannabinoid 1 Receptor. Mol Pharmacol 89:618-29
Xia, Huijing; de Queiroz, Thyago Moreira; Sriramula, Srinivas et al. (2015) Brain ACE2 overexpression reduces DOCA-salt hypertension independently of endoplasmic reticulum stress. Am J Physiol Regul Integr Comp Physiol 308:R370-8
Crawford, Rebecca R; Higdon, Ashlee N; Casey, David B et al. (2015) Multiple lithium-dependent Brugada syndrome unmasking events in a bipolar patient. Clin Case Rep 3:14-8
Crawford, Rebecca R; Prescott, Eugenia T; Sylvester, Charity F et al. (2015) Human CHAC1 Protein Degrades Glutathione, and mRNA Induction Is Regulated by the Transcription Factors ATF4 and ATF3 and a Bipartite ATF/CRE Regulatory Element. J Biol Chem 290:15878-91
Prescott, Eugenia T; Mungrue, Imran N (2014) ABCC6 Out From the Cold: Identification of the ABCC6 Substrate as a Therapy for Pseudoxanthoma Elasticum and Cardiovascular Disease. Austin J Pharmacol Ther 2:
Mao, Hui Z; Ehrhardt, Nicole; Bedoya, Candy et al. (2014) Lipase maturation factor 1 (lmf1) is induced by endoplasmic reticulum stress through activating transcription factor 6α (Atf6α) signaling. J Biol Chem 289:24417-27
Martin, Lisa J; Lau, Edward; Singh, Harpreet et al. (2013) Response to Pomozi et al's research commentary. Circ Res 112:e152-3
Martin, Lisa J; Lau, Edward; Singh, Harpreet et al. (2012) ABCC6 localizes to the mitochondria-associated membrane. Circ Res 111:516-20
Kim, Juyong Brian; Deluna, Andres; Mungrue, Imran N et al. (2012) Effect of 9p21.3 coronary artery disease locus neighboring genes on atherosclerosis in mice. Circulation 126:1896-906
Ghazalpour, Anatole; Bennett, Brian; Petyuk, Vladislav A et al. (2011) Comparative analysis of proteome and transcriptome variation in mouse. PLoS Genet 7:e1001393