Chronic alcohol abuse is a leading cause of chronic pancreatitis; a serious inflammatory disorder of exocrine pancreas resulting into permanent loss of pancreatic functions and multiple co-morbidities including diabetes and pancreatic cancer. However, metabolic basis and mechanism(s) of alcoholic chronic pancreatitis (ACP) are not well understood due to a lack of suitable animal model. Alcohol dehydrogenase (ADH), which metabolizes majority (~90%) of ingested alcohol (ethanol) in the liver, is commonly impaired due to chronic alcohol abuse. Such metabolic state of the liver facilitates formation of fatty pancreas and excessive production of fatty acid ethyl esters (FAEEs), nonoxidative metabolites of ethanol) in the pancreas frequently damaged in chronic alcoholic patients. FAEEs injure pancreatic acinar cells in vitro and cause pancreatitis-like injury in vivo. Using hepatic ADH-deficient (ADH-) and hepatic ADH normal (ADH+) deer mice after chronic ethanol feeding, we found remarkable pancreatic injury, formation of fatty pancreas and several fold increases for pancreatic FAEEs, and endoplasmic reticulum (ER) stress in ethanol-fed ADH- deer mice. The pancreata of ADH- deer mice showed deactivation of AMP-activated protein kinase (AMPK), which regulates lipid homeostasis via controlling lipid synthesis and ?-oxidation of fatty acids. Our preliminary data from primary human pancreatic acinar cells incubated with ethanol shows a dose-dependent formation of FAEEs, and deactivation of AMPK and related downstream signaling. This led our central hypothesis that chronic ingestion of ethanol and its metabolism under hepatic ADH inhibition deactivates AMPK resulting into formation of fatty pancreas and FAEEs contributing to pathogenesis of ACP. This hypothesis will be tested by establishing that pancreatic injury by chronic ethanol ingestion is associated with formation of fatty pancreas and FAEEs in ADH- deer mouse model via deactivation of AMPK. We will also confirm in vivo findings in primary human acinar cells treated with ethanol AMPK activator/inhibitor.
In aim 1, hepatic ADH- and ADH+ deer mice will be fed ethanol daily for 3 months with or without daily injection of AICAR (pharmacological AMPK agonist) in the last 7 days of ethanol feeding. Pancreatic acinar cell injury, AMPK signaling, lipogenesis and fatty acid ?-oxidation, and lipid phenotype including formation of FAEEs will be evaluated.
In aim 2, we will confirm our in vivo findings in primary human pancreatic acinar cells treated with ethanol AICAR and AMPK inhibitor (Compound C). We expect attenuation of fatty pancreas and FAEE formation, and pancreatic injury by AMPK activator. Our project is innovative because we are using a hepatic ADH- deer mouse model (a natural variant of hepatic ADH deficiency) and primary human pancreatic acinar cells for mechanistic approach. This project will be benefited by a strong team of investigators and their experience with deer mouse and pancreatic acinar cell culture models. Overall, findings of this project should lead to a translational project to identify markers and therapeutic targets needed for early intervention of ACP.
Alcoholic pancreatitis is a painful inflammatory disorder of exocrine pancreas and a devastating disease associated with multiple co-morbidities including diabetes and pancreatic cancer. In this project, we will establish metabolic basis and mechanism of alcoholic pancreatitis and evaluate an interventional role of AMPK activation in ethanol-induced pancreatic injury.
|Amer, Samir M; Bhopale, Kamlesh K; Kakumanu, Ramu D et al. (2018) Hepatic alcohol dehydrogenase deficiency induces pancreatic injury in chronic ethanol feeding model of deer mice. Exp Mol Pathol 104:89-97|
|Bhopale, Kamlesh K; Amer, Samir M; Kaphalia, Lata et al. (2017) Proteins Differentially Expressed in the Pancreas of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice Fed Ethanol For 3 Months. Pancreas 46:806-812|
|Bhopale, Kamlesh K; Amer, Samir M; Kaphalia, Lata et al. (2017) Proteomic Profiling of Liver and Plasma in Chronic Ethanol Feeding Model of Hepatic Alcohol Dehydrogenase-Deficient Deer Mice. Alcohol Clin Exp Res 41:1675-1685|
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