The long-term goal of Project 2 is to elucidate the post-transcriptional mechanisms that modulate gene expression in inflammation of the vasculature. Interferon (IFN)-v is the classic activator of monocyte/macro- phages, and it induces rapid transcription of inflammatory growth factors, proteases, chemokines, and gen- erators 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. The termination of inflammation is not a passive process that begins after elimination of the initial insult;in contrast, intrinsic mechanisms actively limit expression of potentially injurious proteins. Recently, investigat- ors have recognized the important role of post-transcriptional processes in limiting or resolving inflammation. We have discovered a novel translational control pathway that acts as an endogenous regulator of the inflammatory response. In myeloid cells, IFN-y induces assembly of the heterotetrameric, IFN-Gamma- Activated inhibitor of Translation (GAIT) complex, which binds an RNA element in the 3'untranslated region of certain pro-inflammatory target mRNAs, e.g., vascular endothelial growth factor-A, and inhibits their translation. In Preliminary Studies we show that one GAIT protein, glutamyl-prolyl-tRNA synthetase (EPRS), is central to the GAIT system because it is responsible for target mRNA recognition, and its function is regu- lated by phosphorylation and binding of the other 3 GAIT proteins. We suggest EPRS is not an inert, protein- binding scaffold, but rather a dynamic system subject to stimulus-inducible modifications that regulate GAIT complex assembly and function. Based on these results, we propose the following hypothesis: Phosphoryl- ation of EPRS by IFN-y-dependent kinases causes conformational changes in EPRS that regulate assembly of the GAIT complex, which silences translation of inflammatory mRNA targets and contributes to the resolu- tion of chronic inflammation. We will test this hypothesis by pursuit of three Specific Aims.
In Aim 1 we will determine the EPRS domains required for GAIT complex assembly and GAIT element-binding.
In Aim 2 we will determine the role of EPRS phosphorylation in GAIT complex assembly and function.
In Aim 3 we will investigate the anti-inflammatory function of EPRS and the GAIT complex in vivo.

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 #
5P01HL029582-29
Application #
8378185
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2012-04-01
Budget End
2013-03-31
Support Year
29
Fiscal Year
2012
Total Cost
$261,118
Indirect Cost
$94,222
Name
Cleveland Clinic Lerner
Department
Type
DUNS #
135781701
City
Cleveland
State
OH
Country
United States
Zip Code
44195
Liu, Caini; Zhu, Liang; Fukuda, Koichi et al. (2017) The flavonoid cyanidin blocks binding of the cytokine interleukin-17A to the IL-17RA subunit to alleviate inflammation in vivo. Sci Signal 10:
Aziz, Moammir H; Cui, Kui; Das, Mitali et al. (2017) The Upregulation of Integrin ?D?2 (CD11d/CD18) on Inflammatory Macrophages Promotes Macrophage Retention in Vascular Lesions and Development of Atherosclerosis. J Immunol 198:4855-4867
Arif, Abul; Terenzi, Fulvia; Potdar, Alka A et al. (2017) EPRS is a critical mTORC1-S6K1 effector that influences adiposity in mice. Nature 542:357-361
Shao, Xinrui; Chen, Siyuan; Yang, Daping et al. (2017) FGF2 cooperates with IL-17 to promote autoimmune inflammation. Sci Rep 7:7024
Arif, Abul; Jia, Jie; Halawani, Dalia et al. (2017) Experimental approaches for investigation of aminoacyl tRNA synthetase phosphorylation. Methods 113:72-82
Israel, Laura; Wang, Ying; Bulek, Katarzyna et al. (2017) Human Adaptive Immunity Rescues an Inborn Error of Innate Immunity. Cell 168:789-800.e10
Zhou, Hao; Yu, Minja; Roychowdhury, Sanjoy et al. (2017) Myeloid-MyD88 Contributes to Ethanol-Induced Liver Injury in Mice Linking Hepatocellular Death to Inflammation. Alcohol Clin Exp Res 41:719-726
Zhou, Hao; Bulek, Katarzyna; Li, Xiao et al. (2017) IRAK2 directs stimulus-dependent nuclear export of inflammatory mRNAs. Elife 6:
Arif, Abul; Yao, Peng; Terenzi, Fulvia et al. (2017) The GAIT translational control system. Wiley Interdiscip Rev RNA :
Wang, Chenhui; Zhang, Cun-Jin; Martin, Bradley N et al. (2017) IL-17 induced NOTCH1 activation in oligodendrocyte progenitor cells enhances proliferation and inflammatory gene expression. Nat Commun 8:15508

Showing the most recent 10 out of 261 publications