Alcohol abuse directly affects 15-30 million Americans and is a major risk factor for several devastating lung diseases including pneumonia. Experimentally, alcohol ingestion causes oxidant stress within the alveolar space and severely compromises alveolar macrophage immune function by dampening GM-CSF signaling and priming of these cells. Clinical studies have verified that chronic alcohol abuse, even in otherwise healthy humans, causes severe oxidant stress and alveolar macrophage dysfunction that parallel the experimental models. Although it has long been recognized that alcohol abuse is associated with zinc deficiency, and that zinc deficiency is particularly damaging to immune cell functions, the role of zinc bioavailability in mediating the alcoholic lung phenotype has not been investigated. Preliminary and published data in this application implicate zinc deficiency in the previously observed defects in GM-CSF signaling to the alveolar macrophage through its master transcription factor, PU.1, but also reveal new evidence that zinc deficiency suppresses activation of the antioxidant response element by inhibiting expression of its master transcription factor, Nrf2. To unify these findings into a single pathophysiological scheme, we hypothesize that alcohol inhibits zinc transport by the alveolar epithelium into the alveolar space, and that the consequent zinc deficiency within the alveolar macrophage impairs both GM-CSF signaling and activation of the antioxidant response element by coordinately interfering with their master transcription factors. Further, we hypothesize that zinc supplementation can mitigate if not reverse the alveolar macrophage dysfunction that causes so much morbidity and mortality in these vulnerable individuals. This research proposal includes three integrated aims that test the overarching hypothesis;specifically, that chronic alcohol ingestion impairs zinc transport across the alveolar epithelium into the alveolar space (Aim 1), which leads to zinc deficiency within the alveolar macrophage that interferes with critical signaling through the antioxidant response element and GM-CSF (Aim 2), and that dietary zinc supplementation can prevent and/or reverse the alcoholic macrophage phenotype in the long-term, whereas GM-CSF and/or thiol antioxidants can rescue the alcoholic macrophage in the acute setting (Aim 3). This project has important implications not only for our understanding of the fundamental mechanisms by which alcohol abuse renders the lung susceptible to a range of acute illnesses, but also for our ability to identify and test novel therapeutic strategies in clinical trials targeted to this highly vulnerable population. Further, the results of this project could change our recommendations for treatment of chronic alcohol abuse;specifically, dietary zinc supplementation could potentially prevent the development of alcohol- mediated susceptibility to lung diseases (and perhaps protect other target organs as well), and thereby prevent or at least limit alcohol-related organ damage while these individuals undergo chronic treatment for their alcohol use disorders.
Alcohol abuse causes many health problems. In particular, even otherwise healthy individuals who consume excessive amounts of alcohol are susceptible to serious lung infections and other causes of respiratory failure, leading to tens of thousands of death in the U.S. alone each year. This project is designed to test the hypothesis that deficiency of the important nutrient zinc is a primary cause of alcohol-related lung injury, and that dietary zinc supplementation could prove to be an effective means of improving lung health in the 15-30 million Americans who suffer from alcohol abuse or dependence.
|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|
|Staitieh, Bashar S; Fan, Xian; Neveu, Wendy et al. (2015) Nrf2 regulates PU.1 expression and activity in the alveolar macrophage. Am J Physiol Lung Cell Mol Physiol 308:L1086-93|
|Overgaard, Christian E; Schlingmann, Barbara; Dorsainvil White, StevenClaude et al. (2015) The relative balance of GM-CSF and TGF-Î²1 regulates lung epithelial barrier function. Am J Physiol Lung Cell Mol Physiol 308:L1212-23|
|Staitieh, Bashar S; Egea, Eduardo E; Fan, Xian et al. (2015) Activation of Alveolar Macrophages with Interferon-Î³ Promotes Antioxidant Defenses via the Nrf2-ARE Pathway. J Clin Cell Immunol 6:|
|Sueblinvong, Viranuj; Tseng, Victor; Smith, Tierra et al. (2014) TGFÎ²1 mediates alcohol-induced Nrf2 suppression in lung fibroblasts. Alcohol Clin Exp Res 38:2731-42|
|Sueblinvong, Viranuj; Neveu, Wendy A; Neujahr, David C et al. (2014) Aging promotes pro-fibrotic matrix production and increases fibrocyte recruitment during acute lung injury. Adv Biosci Biotechnol 5:19-30|
|Sueblinvong, Viranuj; Kerchberger, Vern E; Saghafi, Ramin et al. (2014) Chronic alcohol ingestion primes the lung for bleomycin-induced fibrosis in mice. Alcohol Clin Exp Res 38:336-43|
|Staitieh, Bashar; Guidot, David M (2014) Noninfectious pulmonary complications of human immunodeficiency virus infection. Am J Med Sci 348:502-11|
|Curry-McCoy, Tiana V; Venado, Aida; Guidot, David M et al. (2013) Alcohol ingestion disrupts alveolar epithelial barrier function by activation of macrophage-derived transforming growth factor beta1. Respir Res 14:39|
|Fan, Xian; Staitieh, Bashar S; Jensen, J Spencer et al. (2013) Activating the Nrf2-mediated antioxidant response element restores barrier function in the alveolar epithelium of HIV-1 transgenic rats. Am J Physiol Lung Cell Mol Physiol 305:L267-77|
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