Our previous observations suggest that one of the major physiologic effects of alcohol on the mammalian liver is to inhibit the capacity of the liver to repair itself following a surgical deficit or cellular injury. Indeed, in vitro studies with short term hepatocyte cultures suggest that ethanol inhibits hormone stimulated DNA synthesis and that metabolism of ethanol may be required. There appears to be a critical time in the cell cycle, namely G1, where the hepatocyte may be most susceptible to the action of ethanol. We wish to consolidate and extend these gains and perform studies designed to explore the effect of ethanol at the physiologic, cellular and molecular level. We plan to do the following; 1) perform additional in vitro studies of ethanol on hormone stimulated hepatocyte DNA synthesis. In this regard, we will initiate hepatocyte cultures from animals chronically fed ethanol and determine its long term effect on the hepatocyte proliferative response. We will dispense hepatocyte cultures from rats under the influence of acute ethanol administration in the presence and absence of 4MP. Hepatocyte cultures will be prepared at various times after 2/3 hepatectomy in the setting of acute and chronic ethanol feeding. We are particularly committed to evaluate cells isolated 4 - 12 hours after surgery. 2) Pursue the effect of acute and chronic ethanol feeding on liver regeneration in vivo. We plan to assess the role of alcohol metabolism in relationship to the stage of the cell cycle. We will measure alcohol metabolism in hepatocytes at various intervals following 213 hepatectomy in concord with DNA sythesis and mitosis. Studies are planned to assess ethanol metabolism by hepatocytes in late G1 since these cells appear to be the most susceptible to the inhibitory actions of ethanol. We will use multiparameter flow cytometric analysis for determination of hepatocyte nuclear RNA and DNA content. 3) Examine the possible cellular molecular mechanisms of ethanol on hepatocyte proliferation both in vitro and in vivo. We wish to explore, therefore, ethanol effects on some of earlier events associated with hepatocyte proliferation such as oncogene activation and expression. We will evaluate rat ADH gene expression during various stages of the cell cycle and comparisons will be made to functional studies of alcohol metabolism. Finally, we will measure EGF receptor binding and subsequent autophosphorylation of its receptor and other membrane proteins. We suspect that ethanol may effect the binding and number of EGF receptors particularly prior to and during the G 0 and G 1 transition of the hepatocyte cell cycle. A clinical question to be addressed in this grant proposal. is with ongoing liver injury, the capacity of the liver to repair itself may become important and ethanol consumption may adversely effect this process. For example, continuous cellular injury in the liver that has a diminished capacity to regenerate because of ethanol exposure could promote the development of hepatic failure. Thus, a better understanding of ethanol effects on the hepatic repair process at an experimental level may have important implications with respect to the progression of clinical liver injury induced by acute and chronic alcohol abuse.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AA002666-16
Application #
2042973
Study Section
Biochemistry, Physiology and Medicine Subcommittee (ALCB)
Project Start
1979-07-01
Project End
1994-08-31
Budget Start
1992-09-01
Budget End
1993-08-31
Support Year
16
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02199
Derdak, Zoltan; Villegas, Kristine A; Wands, Jack R (2012) Early growth response-1 transcription factor promotes hepatic fibrosis and steatosis in long-term ethanol-fed Long-Evans rats. Liver Int 32:761-70
de la Monte, Suzanne; Derdak, Zoltan; Wands, Jack R (2012) Alcohol, insulin resistance and the liver-brain axis. J Gastroenterol Hepatol 27 Suppl 2:33-41
de la Monte, Suzanne M; Pang, Maoyin; Chaudhry, Rajeev et al. (2011) Peroxisome proliferator-activated receptor agonist treatment of alcohol-induced hepatic insulin resistance. Hepatol Res 41:386-98
Derdak, Zoltan; Lang, Charles H; Villegas, Kristine A et al. (2011) Activation of p53 enhances apoptosis and insulin resistance in a rat model of alcoholic liver disease. J Hepatol 54:164-72
de la Monte, Suzanne M; Wands, Jack R (2010) Role of central nervous system insulin resistance in fetal alcohol spectrum disorders. J Popul Ther Clin Pharmacol 17:e390-404
He, Jiman; de la Monte, Suzanne; Wands, Jack R (2010) The p85beta regulatory subunit of PI3K serves as a substrate for PTEN protein phosphatase activity during insulin mediated signaling. Biochem Biophys Res Commun 397:513-9
Szabo, Gyongyi; Wands, Jack R; Eken, Ahmet et al. (2010) Alcohol and hepatitis C virus--interactions in immune dysfunctions and liver damage. Alcohol Clin Exp Res 34:1675-86
de la Monte, Suzanne M; Longato, Lisa; Tong, Ming et al. (2009) Insulin resistance and neurodegeneration: roles of obesity, type 2 diabetes mellitus and non-alcoholic steatohepatitis. Curr Opin Investig Drugs 10:1049-60
de la Monte, Suzanne M; Tong, Ming (2009) Mechanisms of nitrosamine-mediated neurodegeneration: potential relevance to sporadic Alzheimer's disease. J Alzheimers Dis 17:817-25
Tong, Ming; Neusner, Alexander; Longato, Lisa et al. (2009) Nitrosamine exposure causes insulin resistance diseases: relevance to type 2 diabetes mellitus, non-alcoholic steatohepatitis, and Alzheimer's disease. J Alzheimers Dis 17:827-44

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