The cellular response to nutritional and environmental stress has been associated with the pathology of many diseases. Major contributors to cell fate decisions in response to stress are: (i) cell-type specific factors, (ii) time and (iii) intensity of stress. Chronic and high intensity stress conditions attenuate survival signals and favor apoptotic signals. This proposal will explore the molecular mechanisms of cell fate decisions during hypertonic stress. Hypertonic stress causes loss of intracellular water, cell shrinkage and macromolecular crowding. Disease-related examples are hyperglycemia in diabetes (HHS, Hyperglycemic Hyperosmolar State), macrophage cell death in inflammatory sites, dehydration of the ocular surface in dry eye syndrome and increased susceptibility to infections and retinal cell apoptosis in diabetic retinopathy. During the previous grant cycle we were the first to identify a novel pathway that promotes cell death during hypertonic stress. We showed that a specific signaling pathway (eIF21-P), the master regulator of survival and apoptotic signals in all stress responses, mediates the cytoplasmic localization of a nuclear protein that represses synthesis of proteins that promote cell survival. This cellular response shifts the balance to cell death (apoptosis) by weakening the survival mechanisms of the stressed cells. Regulation of the subcellular localization of nuclear proteins by extracellular signaling is an understudied and emerging area of research. We propose to identify some of the critical factors which are involved in the switch of balance from survival to apoptosis during hypertonic stress. We will determine (i) the signaling pathways that affect translation of mRNAs coding for proteins that determine cell fate during hypertonic stress. (ii) specific signaling molecules (cleaved tRNAs) involved in inhibition of protein synthesis during hypertonic stress and (iii) the effect of inflammation in hypertonic stress-induced cell death in a model of human disease. These studies will increase our understanding of stress-induced human diseases and generate biological markers that can be used for drug development.

Public Health Relevance

A recently recognized pathology is the increased extracellular osmolarity at sites of inflammation. Increased extracellular osmolarity causes osmotic stress, which leads to loss of intracellular water, cell shrinkage, macromolecular crowding and death. Diseases such as diabetic retinopathy, Hyperglycemic Hyperosmolar State (HHS) in diabetes, macrophage cell death at inflammatory sites, and dehydration of the ocular surface in dry eye syndrome are some examples that involve increased systemic or local extracellular osmolarity. The studies in this proposal will bring new insights into the molecular events that determine cell fate when osmolarities increase above normal and will assist in the development of drugs to attenuate undesirable apoptosis of healthy cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37DK060596-11
Application #
8247712
Study Section
Special Emphasis Panel (ZRG1-EMNR-K (02))
Program Officer
Maruvada, Padma
Project Start
2002-03-15
Project End
2016-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
11
Fiscal Year
2012
Total Cost
$489,740
Indirect Cost
$177,804
Name
Case Western Reserve University
Department
Nutrition
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Dasarathy, Srinivasan; Hatzoglou, Maria (2018) Hyperammonemia and proteostasis in cirrhosis. Curr Opin Clin Nutr Metab Care 21:30-36
Ko, Chih-Wei; Counihan, Daniel; Wu, Jing et al. (2018) Macrophages with a deletion of the phosphoenolpyruvate carboxykinase 1 (Pck1) gene have a more proinflammatory phenotype. J Biol Chem 293:3399-3409
Dery?o, Kamil; Michalec-WawiĆ³rka, Barbara; Krokowski, Dawid et al. (2018) The uL10 protein, a component of the ribosomal P-stalk, is released from the ribosome in nucleolar stress. Biochim Biophys Acta Mol Cell Res 1865:34-47
Krishnamoorthy, Jothilatha; Tenkerian, Clara; Gupta, Jyotsana et al. (2018) Downregulation of PERK activity and eIF2? serine 51 phosphorylation by mTOR complex 1 elicits pro-oxidant and pro-death effects in tuberous sclerosis-deficient cells. Cell Death Dis 9:254
Yadav, Vinita; Gao, Xing-Huang; Willard, Belinda et al. (2017) Hydrogen sulfide modulates eukaryotic translation initiation factor 2? (eIF2?) phosphorylation status in the integrated stress-response pathway. J Biol Chem 292:13143-13153
Roy, Debasish; Farabaugh, Kenneth T; Wu, Jing et al. (2017) Coordinated transcriptional control of adipocyte triglyceride lipase (Atgl) by transcription factors Sp1 and peroxisome proliferator-activated receptor ? (PPAR?) during adipocyte differentiation. J Biol Chem 292:14827-14835
Krokowski, Dawid; Guan, Bo-Jhih; Wu, Jing et al. (2017) GADD34 Function in Protein Trafficking Promotes Adaptation to Hyperosmotic Stress in Human Corneal Cells. Cell Rep 21:2895-2910
Choi, Woo-Gyun; Han, Jaeseok; Kim, Ji-Hyeon et al. (2017) eIF2? phosphorylation is required to prevent hepatocyte death and liver fibrosis in mice challenged with a high fructose diet. Nutr Metab (Lond) 14:48
Ziosi, Marcello; Di Meo, Ivano; Kleiner, Giulio et al. (2017) Coenzyme Q deficiency causes impairment of the sulfide oxidation pathway. EMBO Mol Med 9:96-111
Guan, Bo-Jhih; van Hoef, Vincent; Jobava, Raul et al. (2017) A Unique ISR Program Determines Cellular Responses to Chronic Stress. Mol Cell 68:885-900.e6

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