Apolipoprotein A-V association with intracellular lipid dropletss⃞

Journal of Lipid Research

Joanne Chan¹  Robert O. Ryan²  Trudy M. Forte²  Xiao Shu² 

[1] Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720;Center for Prevention of Obesity, Diabetes, and Cardiovascular Diseases, Children's Hospital Oakland Research Institute, Oakland, CA 94609;

关键词: Hep3B hepatoma cell line;    triglyceride;    very low density lipoprotein;    immunoprecipitation;    confocal fluorescence microscopy;    apolipoprotein B;   

DOI  :  

来源: DOAJ

【 摘 要 】

Apolipoprotein A-V (apoA-V) plays a key role in the regulation of triglyceride (TG) metabolism. Given the very low concentration of apoA-V in plasma, we hypothesized that apoA-V may influence plasma TG levels by affecting the assembly and/or secretion of apoB-containing lipoproteins. When apoA-V was overexpressed in cultured Hep3B cells, neither the amount of apoB secreted nor the density distribution of apoB-containing lipoproteins was affected. Fluorescence microscopy and cell lysate immunoprecipitation studies revealed that apoA-V is not associated with apoB intracellularly, yet immunoprecipitation of apoA-V from the cell culture medium resulted in coprecipitation of apoB. These data suggest that the apoA-V association with apoB-containing lipoproteins is a postsecretory event. Confocal fluorescence microscopy revealed the presence of apoA-V in distinct cellular structures. Based on Nile Red staining, we identified these structures to be intracellular lipid droplets. These data suggest that apoA-V has a unique association with cellular lipids and, therefore, may be involved in the storage or mobilization of intracellular lipids.

【 授权许可】

Unknown