The overall purpose of this proposal is to better understand the molecular mechanisms by which ethanol alters the homeostasis of hepatic GSH and its localization in the liver acinus.
The specific aims are: 1) Effect of ethanol on the GSH homeostasis in periportal (PP) and perivenous (PV) hepatocytes. We will determine the zonation f the changes in the homeostasis of GSH by chronic ethanol feeding previously observed in mixed population of isolated hepatocytes as to whether these are predominant in a specific cell population of the acinus. With enriched population of PP and PV cells we will determine the kinetics of GSH efflux and the compartmentation of GSH in pair and ethanol-fed PP and PV cells. Alternatively, we will study the effect of ethanol feeding on the GSH content in different mitochondrial populations fractionated by flow cytometry. 2) Effect of lipid composition and fluidity on the transport of GSH in sinusoidal membrane vesicles (bLPM). Chronic ethanol feeding increases the fluidity of the sinusoidal plasma membrane which may subsequently affect the hepatic transport of GSH. Therefore, we will determine the effect of changing the lipid composition of the bLPM lipids on the transport of GSH by fusing liposomes of defined lipid composition and cholesterol content to pair- and ethanol- bLPM. Also, we will determine the changing of fluidity independent of lipid composition on the transport of GSH by using agents that intercalate into the plasma membrane increasing its fluidity. 3) Characterization of the kinetics, driving forces of GSH transport in mitochondria from chronic ethanol-fed rats. We will determine in permeabilized rat hepatocytes the kinetics and driving forces of GSH transport in mitochondria and the effects of ethanol feeding on the features of the mitochondrial transport of GSH by reconstituting the extracted mitochondrial inner membrane proteins in artificial or native lipids from both groups.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA009526-02
Application #
2045759
Study Section
Biochemistry, Physiology and Medicine Subcommittee (ALCB)
Project Start
1993-04-01
Project End
1996-03-31
Budget Start
1994-04-01
Budget End
1995-03-31
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Southern California
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Feng, Guoping; Kaplowitz, Neil (2002) Mechanism of staurosporine-induced apoptosis in murine hepatocytes. Am J Physiol Gastrointest Liver Physiol 282:G825-34
Ardite, E; Sans, M; Panes, J et al. (2000) Replenishment of glutathione levels improves mucosal function in experimental acute colitis. Lab Invest 80:735-44
Roman, J; Gimenez, A; Lluis, J M et al. (2000) Enhanced DNA binding and activation of transcription factors NF-kappa B and AP-1 by acetaldehyde in HEPG2 cells. J Biol Chem 275:14684-90
Garcia-Ruiz, C; Colell, A; Paris, R et al. (2000) Direct interaction of GD3 ganglioside with mitochondria generates reactive oxygen species followed by mitochondrial permeability transition, cytochrome c release, and caspase activation. FASEB J 14:847-58
Feng, G; Kaplowitz, N (2000) Colchicine protects mice from the lethal effect of an agonistic anti-Fas antibody. J Clin Invest 105:329-39
Ardite, E; Ramos, C; Rimola, A et al. (1999) Hepatocellular oxidative stress and initial graft injury in human liver transplantation. J Hepatol 31:921-7
Bosch-Morell, F; Martinez-Soriano, F; Colell, A et al. (1998) Chronic ethanol feeding induces cellular antioxidants decrease and oxidative stress in rat peripheral nerves. Effect of S-adenosyl-L-methionine and N-acetyl-L-cysteine. Free Radic Biol Med 25:365-8
Colell, A; Garcia-Ruiz, C; Miranda, M et al. (1998) Selective glutathione depletion of mitochondria by ethanol sensitizes hepatocytes to tumor necrosis factor. Gastroenterology 115:1541-51
Fernandez-Checa, J C; Garcia-Ruiz, C; Colell, A et al. (1998) Oxidative stress: role of mitochondria and protection by glutathione. Biofactors 8:7-11
Ardite, E; Panes, J; Miranda, M et al. (1998) Effects of steroid treatment on activation of nuclear factor kappaB in patients with inflammatory bowel disease. Br J Pharmacol 124:431-3

Showing the most recent 10 out of 26 publications