Chronic alcohol abuse and alcoholism are associated with high morbidity and mortality and known to cause major health problems such as alcoholic liver disease. Altered protein trafficking and glycosylation, and increased apoptosis have been reported in ethanol-exposed liver cells. But the mechanism remains unresolved. Recently, we found that non-muscle myosin IIA (NMIIA), a motor protein, interacts with the cytoplasmic tail of Golgi glycosyltransferases (GT) to induce Golgi fragmentation in cells under stress. The Golgi fragmentation was detected in hepatocytes exposed to alcohol in vitro and in vivo. Alcohol metabolites are responsible for this effect. Alcohol treatment also increases Rab6A GTPase, NMIIA, caspase-3 activity, NMIIA-GT complexes but decreases Golgi matrix protein, Giantin, and GT. In control cells, knockdown of Giantin retains GT in the endoplasmic reticulum. Knockdown of NMIIA or Rab6A prevents alcohol treatment- induced Golgi fragmentation. The results suggest that NMIIA and Rab6A are intimately involved in Golgi fragmentation induced by alcohol treatment. Further, the reduction of GT induced by alcohol treatment could be explained by (a) its elevated Golgi-to-endoplasmic reticulum retrograde transport forced by increased NMIIA-GT complexes coupled with (b) its impaired Golgi targeting resulted from elevated degradation of Giantin caused by activated caspase-3 activity. We propose to test the hypothesis that alcohol treatment- induced Golgi fragmentation is responsible for reduced glycosylation and function of asialoglycoprotein receptors as well as induction of apoptosis. The four specific aims of the proposed study are to: 1. Examine how during alcohol-specific Golgi fragmentation Rab6A regulates the interaction of NMIIA with GT followed by increased NMIIA-GT complexes; 2. Examine how elevated caspases-3 activity induced by alcohol treatment impairs ER-to-Golgi transport of GT; 3. Determine how the alcohol treatment-induced Golgi fragmentation affects glycan structure and function of asialoglycoprotein receptors including apoptosis; and 4. Validate the results of specific aims 1-3 obtained in VA-13 cells in the hepatocytes of alcohol-treated mice with and without functional asialoglycoprotein receptors. Accomplishment of the goal of the proposed study would expand our understanding of the regulation of cell death caused by ethanol abuse and help identify potential targets for developing therapy to treat alcoholic liver disease.

Public Health Relevance

Chronic alcohol abuse can increase apoptosis of hepatocytes, which leads to liver injury and alcohol liver disease. Current application will elucidate how alcohol treatment-induced Golgi fragmentation results in elevated apoptosis of hepatocytes. The results could help identify the molecules/events that are responsible for the development of alcoholic liver apoptosis, which could lead to development of mechanism-based therapy to treat alcohol liver disease.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
5K01AA022979-03
Application #
9127886
Study Section
Neuroscience Review Subcommittee (AA)
Program Officer
Gao, Peter
Project Start
2014-09-01
Project End
2019-08-31
Budget Start
2016-09-01
Budget End
2017-08-31
Support Year
3
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Nebraska Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
168559177
City
Omaha
State
NE
Country
United States
Zip Code
68198
Casey, Carol A; Thomes, Paul; Manca, Sonia et al. (2018) Giantin Is Required for Post-Alcohol Recovery of Golgi in Liver Cells. Biomolecules 8:
Petrosyan, Armen; Casey, Carol A; Cheng, Pi-Wan (2016) The role of Rab6a and phosphorylation of non-muscle myosin IIA tailpiece in alcohol-induced Golgi disorganization. Sci Rep 6:31962
Casey, Carol A; Bhat, Ganapati; Holzapfel, Melissa S et al. (2016) Study of Ethanol-Induced Golgi Disorganization Reveals the Potential Mechanism of Alcohol-Impaired N-Glycosylation. Alcohol Clin Exp Res 40:2573-2590
Kubyshkin, Anatoliy; Chegodar, Denis; Katsev, Andrew et al. (2016) Antimicrobial Effects of Silver Nanoparticles Stabilized in Solution by Sodium Alginate. Biochem Mol Biol J 2:
Petrosyan, Armen (2015) Onco-Golgi: Is Fragmentation a Gate to Cancer Progression? Biochem Mol Biol J 1:
Petrosyan, Armen; Cheng, Pi-Wan; Clemens, Dahn L et al. (2015) Downregulation of the small GTPase SAR1A: a key event underlying alcohol-induced Golgi fragmentation in hepatocytes. Sci Rep 5:17127
Petrosyan, Armen; Ali, Mohamed F; Cheng, Pi-Wan (2015) Keratin 1 plays a critical role in golgi localization of core 2 N-acetylglucosaminyltransferase M via interaction with its cytoplasmic tail. J Biol Chem 290:6256-69
Petrosyan, Armen; Holzapfel, Melissa S; Muirhead, David E et al. (2014) Restoration of compact Golgi morphology in advanced prostate cancer enhances susceptibility to galectin-1-induced apoptosis by modifying mucin O-glycan synthesis. Mol Cancer Res 12:1704-16
Seo, Song Yi; Lee, Ga Hyun; Lee, Se Guen et al. (2012) Alginate-based composite sponge containing silver nanoparticles synthesized in situ. Carbohydr Polym 90:109-15