The long-term goal of Project 2 is to elucidate the role of ribosomal protein L13a in post-transcriptional regulation of inflammatory gene expression in monocyte/macrophages. Interferon (IFN)-gamma is the classic activator of monocyte/macrophages;it induces rapid transcription of inflammatory growth factors, proteases, chemokines, and generators of radical species. If unregulated, this process becomes chronic and monocyte/macrophage products accumulate, damage host tissue, and contribute to chronic disorders of blood vessels, e.g., atherosclerosis. We have discovered a novel translational control pathway that acts as an endogenous regulator of the inflammatory response. In myeloid cells, IFN-gamma induces assembly of the IFN-Gamma-Activated Inhibitor of Translation (GAIT) complex, which binds an RNA element in the 3?untranslated region of pro-inflammatory target mRNAs, and inhibits their translation. In Preliminary Studies we show that one GAIT protein, L13a, has a critical role in the GAIT system: its function is regulated by phosphorylation, it induces conformational changes in other GAIT proteins to regulate target mRNA recognition, and by interaction with eIF4G it is responsible for the observed translational silencing. Recently, we have shown that stress can alter GAIT system activity and influence inflammatory gene expression. Based on these results, we propose the following hypothesis: IFN-gamma-dependent phosphorylation of L13a induces a conformational change that facilitates its release from the 60S ribosomal subunit, formation of the GAIT complex, and binding to eIF4G to cause translational silencing of inflammatory transcripts;moreover, physiological stress can alter GAIT system function and inflammatory gene expression. We will test this hypothesis by pursuit of three Specific Aims.
In Aim 1 we will determine the mechanism of inducible release of L13a from ribosome in the response to inflammatory stimulus.
In Aim 2 we will determine L13a interactions required for GAIT complex assembly and silencing of inflammatory gene expression.
In Aim 3 we will determine the mechanisms by which stress alters GAIT complex function and inflammatory gene expression.

Public Health Relevance

Our studies will elucidate a new pathway that regulates the synthesis of inflammatory proteins by macrophages, an important process in the development of vascular diseases such as atherosclerosis. The pathway under investigation contributes to the limitation and resolution of chronic inflammation, an important causative factor in disease progression. A deeper understanding of inflammatory stop pathways is important because defects in these pathways can contribute to vascular disorders, and because the pathway itself may present alternative targets for development of novel anti-inflammatory therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL076491-10
Application #
8605052
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
10
Fiscal Year
2014
Total Cost
$235,599
Indirect Cost
$80,439
Name
Cleveland Clinic Lerner
Department
Type
DUNS #
135781701
City
Cleveland
State
OH
Country
United States
Zip Code
44195
Wang, Zeneng; DiDonato, Joseph A; Buffa, Jennifer et al. (2016) Eosinophil Peroxidase Catalyzed Protein Carbamylation Participates in Asthma. J Biol Chem 291:22118-22135
Zhu, Weifei; Gregory, Jill C; Org, Elin et al. (2016) Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk. Cell 165:111-24
Grodin, Justin L; Verbrugge, Frederik H; Ellis, Stephen G et al. (2016) Importance of Abnormal Chloride Homeostasis in Stable Chronic Heart Failure. Circ Heart Fail 9:e002453
Hartiala, Jaana A; Tang, W H Wilson; Wang, Zeneng et al. (2016) Genome-wide association study and targeted metabolomics identifies sex-specific association of CPS1 with coronary artery disease. Nat Commun 7:10558
Gu, Xiaodong; Wu, Zhiping; Huang, Ying et al. (2016) A Systematic Investigation of Structure/Function Requirements for the Apolipoprotein A-I/Lecithin Cholesterol Acyltransferase Interaction Loop of High-density Lipoprotein. J Biol Chem 291:6386-95
Senthong, Vichai; Wu, Yuping; Hazen, Stanley L et al. (2016) Predicting long-term prognosis in stable peripheral artery disease with baseline functional capacity estimated by the Duke Activity Status Index. Am Heart J 184:17-25
Hammadah, Muhammad; Brennan, Marie-Luise; Wu, Yuping et al. (2016) Usefulness of Relative Hypochromia in Risk Stratification for Nonanemic Patients With Chronic Heart Failure. Am J Cardiol 117:1299-304
Senthong, Vichai; Li, Xinmin S; Hudec, Timothy et al. (2016) Plasma Trimethylamine N-Oxide, a Gut Microbe-Generated Phosphatidylcholine Metabolite, Is Associated With Atherosclerotic Burden. J Am Coll Cardiol 67:2620-8
Loley, Christina; Alver, Maris; Assimes, Themistocles L et al. (2016) No Association of Coronary Artery Disease with X-Chromosomal Variants in Comprehensive International Meta-Analysis. Sci Rep 6:35278
Paz Y Mar, Hugo L; Hazen, Stanley L; Tracy, Russell P et al. (2016) Effect of Continuous Positive Airway Pressure on Cardiovascular Biomarkers: The Sleep Apnea Stress Randomized Controlled Trial. Chest 150:80-90

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