Members of the Emory Alcohol and Lung Biology Center unveiled a strong association between ethanol abuse and susceptibility to acute lung injury. We hypothesized that one mechanism by which ethanol promotes acute lung injury relates to the activation of tissue remodeling characterized by both increased expression and degradation of lung extracellular matrices. We set out to investigate this during the prior funding period and showed that chronic exposure to ethanol in rodents leads to the activation in lung of matrix metalloproteinases and increased collagen fragmentation, increased expression of Transforming Growth Factor-pi (TGFp), and increased expression of fibronectin, a matrix glycoprotein implicated in injury and repair. We also showed evidence of activation of lung tissue remodeling in otherwise 'healthy' alcoholics. More importantly, these studies unveiled the lung fibroblast as a target for ethanol. Thus, we now propose to explore the mechanisms by which ethanol affects fibroblast functions, the signaling pathways triggered, and the potential role of extracellular matrices as modulators of these events. Interestingly, we found that ethanol-induced oxidative stress via oxidation of thiol disulfide couples activates non-neuronal nicotinic acetylcholine receptors (nAChRs) and triggers TGF|31/Smad3 signaling followed by the induction of genes involved in control of matrix expression and myofibroblast transdifferentiation. We also found that this pathway results in the deposition of fibronectin-rich matrices that help sustain the 'alcoholic phenotype', whereas peroxisome proliferator activated receptors-gamma (PPARy) downregulate these responses. These novel observations led us to postulate that in lung fibroblasts, ethanol-induced oxidative stress triggers redox signaling via nAChRs that leads to TGFp1/Smad3 signaling. In turn, TGFp1/Smad3 signaling promotes alterations in fibroblast phenotype and the production of fibronectin-rich extracellular matrices that render the lung susceptible to fibroproliferation in the setting of acute lung injury. These events are counterbalanced by PPARy. This hypothesis will be tested in aims designed to: 1) Identify the nAChRs responsible for mediating the effects of ethanol in lung fibroblasts. 2) Examine the role of TGFp1/Smad3 signaling in ethanol-induced susceptibility to acute lung injury. 3) Explore the mechanisms by which fibroblast-derived fibronectin-rich matrices contribute to the ethanol-induced effects. 4) Determine the role of PPARy in downregulating ethanol-induced fibroblast activation and matrix expression, and examine how manipulation of this pathway in vivo affects ethanolrelated consequences. Lav summary: This project will examine how chronic exposure to alcohol activates lung fibroblasts and promotes acute lung injury.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Specialized Center (P50)
Project #
5P50AA013757-10
Application #
8426097
Study Section
Special Emphasis Panel (ZAA1-BB)
Project Start
Project End
2014-12-31
Budget Start
2013-01-01
Budget End
2013-12-31
Support Year
10
Fiscal Year
2013
Total Cost
$234,314
Indirect Cost
$52,815
Name
Emory University
Department
Type
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Gauthier, Theresa W; Guidot, David M; Kelleman, Michael S et al. (2016) Maternal Alcohol Use During Pregnancy and Associated Morbidities in Very Low Birth Weight Newborns. Am J Med Sci 352:368-375
Gauthier, Theresa W; Brown, Lou Ann S (2016) In utero alcohol effects on foetal, neonatal and childhood lung disease. Paediatr Respir Rev :
Margoles, Lindsay M; Mittal, Rohit; Klingensmith, Nathan J et al. (2016) Chronic Alcohol Ingestion Delays T Cell Activation and Effector Function in Sepsis. PLoS One 11:e0165886
Kempker, Jordan A; Magee, Matthew J; Cegielski, J Peter et al. (2016) Associations Between Vitamin D Level and Hospitalizations With and Without an Infection in a National Cohort of Medicare Beneficiaries. Am J Epidemiol 183:920-9
Yeligar, Samantha M; Mehta, Ashish J; Harris, Frank L et al. (2016) Peroxisome Proliferator-Activated Receptor γ Regulates Chronic Alcohol-Induced Alveolar Macrophage Dysfunction. Am J Respir Cell Mol Biol 55:35-46
Sueblinvong, Viranuj; Mills, Stephen T; Neujahr, David C et al. (2016) Nuclear Thioredoxin-1 Overexpression Attenuates Alcohol-Mediated Nrf2 Signaling and Lung Fibrosis. Alcohol Clin Exp Res 40:1846-56
Cochi, Shea E; Kempker, Jordan A; Annangi, Srinadh et al. (2016) Mortality Trends of Acute Respiratory Distress Syndrome in the United States from 1999 to 2013. Ann Am Thorac Soc 13:1742-1751
Schlingmann, Barbara; Overgaard, Christian E; Molina, Samuel A et al. (2016) Regulation of claudin/zonula occludens-1 complexes by hetero-claudin interactions. Nat Commun 7:12276
Alford, Lea M; Stoddard, Daniel; Li, Jennifer H et al. (2016) The nexin link and B-tubule glutamylation maintain the alignment of outer doublets in the ciliary axoneme. Cytoskeleton (Hoboken) 73:331-40
Klingensmith, Nathan J; Yoseph, Benyam P; Liang, Zhe et al. (2016) Epidermal Growth Factor Improves Intestinal Integrity and Survival in Murine Sepsis Following Chronic Alcohol Ingestion. Shock :

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