Alcoholism remains the most common form of drug abuse in the United States. Alcohol abuse is associated with pancreas disease, and may predispose to many malignant disorders including pancreatic cancer. Alcohol is known to alter metabolism and function in distinct subcellular compartments. The exocrine pancreas has the most extensive endoplasmic reticulum (ER) system of any tissue, in order to maintain a high rate of production, processing and secretion of proteins. Although disorders of ER function are thought to underlie alcohol toxicity, there is little information on precise detrimental effects of alcohol that cause ER dysfunction and promote its propagation into pathophysiologic features of pancreatitis including aberrant digestive enzyme activation and acinar cell death. The overall goal of this project is to determine the pathologic biochemical events of alcohol abuse that impair ER function, protein folding and transit through the secretory pathway. Our recently developed mouse models of ER dysfunction in the exocrine pancreas combine chronic alcohol feeding with genetic attenuation of XBP1, a key element of the adaptive unfolded protein response that regulates ER homeostasis in pancreatic acinar cells. We envision that the disruption of the adaptive response in our mouse model of ER stress will reveal sensitizing pathologic effects of ethanol responsible for ER dysfunction, impaired protein synthesis and secretion that act as initial events triggering eventual widespread inflammation. Events downstream of ER dysfunction, including upregulation of homeostatic autophagy to degrade misfolded proteins, likely contribute to the further propagation of ethanol-induced oxidative damage into pancreatitis. The advantages of our models, together with our state-of-the art proteomic and metabolomic methodologies will facilitate identification of key proteins involved in maintaining ER function and cellular homeostasis in the exocrine pancreas during alcohol abuse. Our innovative techniques and approach will enable us to determine the effects of alcohol on redox cycle intermediates and the redox status, structure and turnover of key ER oxidoreductases involved in oxidative folding and endosomal/autophagolysosomal proteins in vivo. We anticipate that these techniques will help us to identify many novel early steps in alcohol-induced pancreatic injury. We will also examine the consequences of impaired protein processing on the pathological response in the exocrine pancreas. The completion of these aims as described in the research plan will yield significant findings to accelerate progress in understanding the complexity of alcohol-associated pancreatic diseases and other disorders associated with alcohol abuse.
Many toxic substances including alcohol induce damage to the pancreas and the integrity of the organ depends on its capacity to withstand and repair such damage. Disturbances in this capacity by genetic, nutritional or environmental factors lead to painful and potentially fatal disorders such as chronic pancreatitis and pancreatic cancer. Advancing new techniques will improve our understanding of the mechanisms of alcohol-induced pancreas damage and aid in the development of new therapeutic strategies to prevent and treat these disorders.
|Dawson, David W; Hertzer, Kathleen; Moro, Aune et al. (2013) High-fat, high-calorie diet promotes early pancreatic neoplasia in the conditional KrasG12D mouse model. Cancer Prev Res (Phila) 6:1064-73|
|Edderkaoui, Mouad; Lugea, Aurelia; Hui, Hongxiang et al. (2013) Ellagic acid and embelin affect key cellular components of pancreatic adenocarcinoma, cancer, and stellate cells. Nutr Cancer 65:1232-44|
|Apte, Minoti V; Wilson, Jeremy S; Lugea, Aurelia et al. (2013) A starring role for stellate cells in the pancreatic cancer microenvironment. Gastroenterology 144:1210-9|
|Pandol, Stephen; Gukovskaya, Anna; Edderkaoui, Mouad et al. (2012) Epidemiology, risk factors, and the promotion of pancreatic cancer: role of the stellate cell. J Gastroenterol Hepatol 27 Suppl 2:127-34|