The long-term OBJECTIVE of the project is to determine the mechanism and consequences of ethanol effects on cell signaling mediated via tyrosine kinase (TK) and mitogen activated protein kinases (MAPK). Preliminary results suggest that ethanol modulated both kinases. In liver cells (BNLCL2) and rat hepatocytes, ethanol dramatically potentiates MAPK activation by serum. This is not due to upregulation of MAPK protein or physical interaction between ethanol and MAPK (p42 and p44) and therefore may be due to modulation on post-receptor signaling steps. The central hypothesis is that ethanol modulates serum-stimulated TK and Ras-Raf-MAPKK cascade leading to potentiation of MAPK and its translocation into the nucleus. Rat hepatocytes will be the major model of the proposal. There are three aims:
Aim 1. To determine pharmacology of serum stimulated tyrosine and MAP kinases in rat hepatocytes. Serum activated MAPK will be determined in ethanol (10-100 mM) treated (2-4 days) rat hepatocytes. Next these parameters will be tested in hepatocytes from control (CH) and ethanol-fed (EH) rats.
Aim II. To determine the mechanism of ethanol potentiation of serum stimulated MAPK. Involvement of Ras activation (active Ras GTP form) and Ras-Raf-interaction in this ethanol effect will be investigated.
Aim III. To determine nuclear translocation of MAPK by ethanol and its downstream relevance. MAPK levels in the nucleus of ethanol-treated hepatocytes (Aim1) will be determined. Next its level in the nuclei of CH and EH (+ serum stimulation) will be established. Consequences of the MAPK potentiation on c-PLA2 and of its nuclear translocation on the expression of acute phase proteins will be ascertained. Significance: This project will establish the mechanism and molecular target(s) involved in ethanol potentiation of serum stimulated MAPK. New knowledge on the nuclear effects of ethanol on MAPK will be gained. Ethanol potentiated MAP Kinase may emerge an as important link between cytosol and nucleus to elicit nuclear responses to ethanol. Such molecular elucidation of the ethanol actions offers the potential to design therapeutic tools to detect, treat, and prevent ethanol-induced liver injury.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
1R01AA011962-01
Application #
2679989
Study Section
Special Emphasis Panel (ZRG4-ALTX-4 (01))
Project Start
1998-09-30
Project End
2002-06-30
Budget Start
1998-09-30
Budget End
1999-06-30
Support Year
1
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Missouri-Columbia
Department
Pharmacology
Type
Schools of Medicine
DUNS #
112205955
City
Columbia
State
MO
Country
United States
Zip Code
65211
Aroor, Annayya R; Jackson, Daniel E; Shukla, Shivendra D (2012) Dysregulated phosphorylation and nuclear translocation of cyclic AMP response element binding protein (CREB) in rat liver after chronic ethanol binge. Eur J Pharmacol 679:101-8
Aroor, Annayya R; Jackson, Daniel E; Shukla, Shivendra D (2011) Elevated activation of ERK1 and ERK2 accompany enhanced liver injury following alcohol binge in chronically ethanol-fed rats. Alcohol Clin Exp Res 35:2128-38
Aroor, Annayya R; James, Taryn T; Jackson, Daniel E et al. (2010) Differential changes in MAP kinases, histone modifications, and liver injury in rats acutely treated with ethanol. Alcohol Clin Exp Res 34:1543-51
Aroor, Annayya R; Lee, Youn Ju; Shukla, Shivendra D (2009) Activation of MEK 1/2 and p42/44 MAPK by angiotensin II in hepatocyte nucleus and their potentiation by ethanol. Alcohol 43:315-22
Weng, Yu-I; Aroor, Annayya R; Shukla, Shivendra D (2008) Ethanol inhibition of angiotensin II-stimulated Tyr705 and Ser727 STAT3 phosphorylation in cultured rat hepatocytes: relevance to activation of p42/44 mitogen-activated protein kinase. Alcohol 42:397-406
Pal-Bhadra, Manika; Bhadra, Utpal; Jackson, Daniel E et al. (2007) Distinct methylation patterns in histone H3 at Lys-4 and Lys-9 correlate with up- &down-regulation of genes by ethanol in hepatocytes. Life Sci 81:979-87
Lee, Youn Ju; Shukla, Shivendra D (2007) Histone H3 phosphorylation at serine 10 and serine 28 is mediated by p38 MAPK in rat hepatocytes exposed to ethanol and acetaldehyde. Eur J Pharmacol 573:29-38
Shukla, Shivendra D; Lee, Youn Ju; Park, Pil-hoon et al. (2007) Acetaldehyde alters MAP kinase signalling and epigenetic histone modifications in hepatocytes. Novartis Found Symp 285:217-24;discussion 224-8
Park, Pil-Hoon; Aroor, Annayya R; Shukla, Shivendra D (2006) Role of Ras in ethanol modulation of angiotensin II activated p42/p44 MAP kinase in rat hepatocytes. Life Sci 79:2357-63
Shukla, Shivendra D; Aroor, Annayya R (2006) Epigenetic effects of ethanol on liver and gastrointestinal injury. World J Gastroenterol 12:5265-71

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