Trypanosoma cruzi epimastigotes store cholesteryl esters in lipid droplets after cholesterol endocytosis
| Autor: | Georgia C. Atella, Gonzalo Visbal, Miria G. Pereira, Susana Frasés, Tatiana F. R. Costa, Wanderley de Souza, Narcisa Cunha-e-Silva |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Trypanosoma cruzi Endocytic cycle Biology Endocytosis Gas Chromatography-Mass Spectrometry 03 medical and health sciences chemistry.chemical_compound Microscopy Electron Transmission Lipid droplet Lysosome Organelle medicine Molecular Biology Diacylglycerol kinase 030102 biochemistry & molecular biology Endoplasmic reticulum Lipid Droplets 030104 developmental biology medicine.anatomical_structure Cholesterol chemistry Biochemistry Microscopy Fluorescence Cholesteryl ester lipids (amino acids peptides and proteins) Parasitology Cholesterol Esters Chromatography Thin Layer |
| Zdroj: | Molecular and biochemical parasitology. 224 |
| ISSN: | 1872-9428 |
| Popis: | The Chagas disease agent Trypanosoma cruzi proliferates in the insect vector as highly endocytic epimastigotes that store nutrients, including lipids in reservosomes (lysosome related compartments). Although nutrient storage is important for epimastigote transformation into infective metacyclics, the epimastigote lipid droplets (LDs) remain uncharacterized. Here, we characterized the epimastigote LDs and examined their relationship with the endocytic pathway. Fluorescence microscopy using BODIPY showed that LDs have high neutral lipid content and harbor Rab18, differently from other lipid-rich organelles (such as reservosomes). Using transmission electron microscopy (TEM), we observed a close relationship between LDs and the endoplasmic reticulum, mitochondria and glycosomes. We developed a reproducible protocol to isolate LDs, and showed (by HTPLC and GC/MS analyses) that they have 89% neutral lipids and 11% phospholipids, which are likely to form the LD monolayer seen by TEM. The LD neutral lipids were mostly sterols, although triacylglycerol, diacylglycerol, monoacylglycerol and free fatty acids (FFA) were also found. Endocytosis of 3H-labeled cholesterol-BSA showed that internalized cholesterol is stored in LDs mostly in the cholesteryl ester form. Together, these results suggest that exogenous cholesterol internalized by endocytosis reaches the reservosomes and is then stored into LDs after esterification. |
| Databáze: | OpenAIRE |
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