Alcohol effect on Golgi morphology and function

酒精对高尔基体形态和功能的影响

基本信息

批准号：
9127886
负责人：
Armen Petrosyan
金额：
$ 11.32万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2019-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9127886
关键词：
Affect Alcohol abuse Alcohol dehydrogenase Alcoholic Hepatitis Alcoholic Liver Cirrhosis Alcoholic Liver Diseases Alcoholic liver damage Alcoholism Alcohols Animal Feed Apoptosis Apoptotic Asialoglycoprotein Receptor Asialoglycoproteins Binding CASP3 gene Cell Death Cell Line Cell physiology Cells Cessation of life Chronic Clinical Complex Coupled Cytochrome P450 Cytoplasmic Tail Development Disease Docking Endoplasmic Reticulum Enzymes Ethanol Event Excision Goals Golgi Apparatus Golgi Targeting Guanosine Triphosphate Phosphohydrolases Health HepG2 Hepatocyte Hepatomegaly Impairment In Vitro Induction of Apoptosis Injury to Liver Lead Ligand Binding Liver Liver diseases Mediating Membrane Morbidity - disease rate Morphology Motor Mus Nonmuscle Myosin Type IIA Polysaccharides Post-Translational Protein Processing Process Property Protein Glycosylation Proteins Regulation Reporting Role Stress Structure Testing alcohol abuse therapy alcohol effect alcohol exposure base chronic alcohol ingestion feeding glycosylation glycosyltransferase in vivo knock-down liver injury macrogolgin mortality new therapeutic target non-muscle myosin prevent problem drinker protein transport retrograde transport therapy development trafficking

项目摘要

DESCRIPTION (provided by applicant): 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.

描述（由申请人提供）：长期酗酒和酗酒与高发病率和死亡率相关，并已知会导致酒精性肝病等重大健康问题。据报道，暴露于乙醇的肝细胞中蛋白质运输和糖基化发生改变，细胞凋亡增加。但其机制仍未解决。最近，我们发现非肌肉肌球蛋白IIA（NMIIA）是一种运动蛋白，与高尔基体糖基转移酶（GT）的细胞质尾部相互作用，诱导细胞在应激下高尔基体断裂。在体外和体内暴露于酒精的肝细胞中检测到高尔基体碎片。酒精代谢物是造成这种效应的原因。酒精治疗还会增加 Rab6A GTPase、NMIIA、caspase-3 活性、NMIIA-GT 复合物，但会降低高尔基体基质蛋白、Giantin 和 GT。在对照细胞中，Giantin 的敲低使 GT 保留在内质网中。 NMIIA 或 Rab6A 的敲低可防止酒精治疗引起的高尔基体断裂。结果表明，NMIIA 和 Rab6A 与酒精处理诱导的高尔基体断裂密切相关。此外，酒精治疗引起的 GT 减少可以解释为：(a) NMIIA-GT 复合物增加迫使高尔基体到内质网逆行运输升高，加上 (b) 由于巨人汀降解增加导致高尔基体靶向受损通过激活 caspase-3 活性。我们建议检验以下假设：酒精治疗诱导的高尔基体断裂是导致脱唾液酸糖蛋白受体糖基化和功能减少以及细胞凋亡诱导的原因。拟议研究的四个具体目标是： 1. 检查在酒精特异性高尔基体断裂过程中 Rab6A 如何调节 NMIIA 与 GT 的相互作用，从而增加 NMIIA-GT 复合物； 2. 检查酒精处理引起的 caspase-3 活性升高如何损害 GT 的 ER 至高尔基体转运； 3. 确定酒精治疗引起的高尔基体断裂如何影响脱唾液酸糖蛋白受体的聚糖结构和功能，包括细胞凋亡； 4.验证在具有或不具有功能性脱唾液酸糖蛋白受体的酒精处理小鼠的肝细胞中的VA-13细胞中获得的特定目标1-3的结果。完成拟议研究的目标将扩大我们对乙醇滥用引起的细胞死亡调节的理解，并有助于确定开发治疗酒精性肝病的潜在靶点。