Dietary cholesterol and apolipoprotein A-I are trafficked in endosomes and lysosomes in the live zebrafish intestine
| Autor: | Meng-Chieh Shen, Steven A. Farber, Oscar E. Reyes Gaido, Blake A. Caldwell, Jessica P. Otis |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Apolipoprotein B Physiology Endosome Endosomes Cholesterol analog Cholesterol Dietary 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Physiology (medical) polycyclic compounds Zebrafish larvae Intracellular cholesterol Animals Zebrafish Apolipoprotein A-I Hepatology biology Chemistry Cholesterol Gastroenterology Biological Transport biology.organism_classification Cell biology Intestines Protein Transport Enterocytes 030104 developmental biology biology.protein lipids (amino acids peptides and proteins) Lipoproteins HDL Lysosomes 030217 neurology & neurosurgery Dietary Cholesterol Research Article |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 316:G350-G365 |
| ISSN: | 1522-1547 0193-1857 |
| Popis: | Difficulty in imaging the vertebrate intestine in vivo has hindered our ability to model nutrient and protein trafficking from both the lumenal and basolateral aspects of enterocytes. Our goal was to use live confocal imaging to increase understanding of intestinal trafficking of dietary cholesterol and apolipoprotein A-I (APOA-I), the main structural component of high-density lipoproteins. We developed a novel assay to visualize live dietary cholesterol trafficking in the zebrafish intestine by feeding TopFluor-cholesterol (TF-cholesterol), a fluorescent cholesterol analog, in a lipid-rich, chicken egg yolk feed. Quantitative microscopy of transgenic zebrafish expressing fluorescently tagged protein markers of early, recycling, and late endosomes/lysosomes provided the first evidence, to our knowledge, of cholesterol transport in the intestinal endosomal-lysosomal trafficking system. To study APOA-I dynamics, transgenic zebrafish expressing an APOA-I fluorescent fusion protein (APOA-I-mCherry) from tissue-specific promoters were created. These zebrafish demonstrated that APOA-I-mCherry derived from the intestine accumulated in the liver and vice versa. Additionally, intracellular APOA-I-mCherry localized to endosomes and lysosomes in the intestine and liver. Moreover, live imaging demonstrated that APOA-I-mCherry colocalized with dietary TF-cholesterol in enterocytes, and this colocalization increased with feeding time. This study provides a new set of tools for the study of cellular lipid biology and elucidates a key role for endosomal-lysosomal trafficking of intestinal cholesterol and APOA-I.NEW & NOTEWORTHY A fluorescent cholesterol analog was fed to live, translucent larval zebrafish to visualize intracellular cholesterol and apolipoprotein A-I (APOA-I) trafficking. With this model intestinal endosomal-lysosomal cholesterol trafficking was observed for the first time. A new APOA-I fusion protein (APOA-I-mCherry) expressed from tissue-specific promoters was secreted into the circulation and revealed that liver-derived APOA-I-mCherry accumulates in the intestine and vice versa. Intestinal, intracellular APOA-I-mCherry was observed in endosomes and lysosomes and colocalized with dietary cholesterol. |
| Databáze: | OpenAIRE |
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