Hepatic subcellular distribution of squalene changes according to the experimental setting
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Squalene is the main unsaponifiable component of virgin olive oil, the main source of dietary fat in Mediterranean diet, traditionally associated with a less frequency of cardiovascular diseases. In this study, two experimental approaches were used. In the first, New Zealand rabbits fed for 4 weeks with a chow diet enriched in 1% sunflower oil for the control group, and in 1% of sunflower oil and 0.5% squalene for the squalene group. In the second, APOE KO mice received either Western diet or Western diet enriched in 0.5% squalene for 11 weeks. In both studies, liver samples were obtained and analyzed for their squalene content by gas chromatography-mass spectrometry. Hepatic distribution of squalene was also characterized in isolated subcellular organelles. Our results show that dietary squalene accumulates in the liver and a differential distribution according to studied model. In this regard, rabbits accumulated in cytoplasm within small size vesicles, whose size was not big enough to be considered lipid droplets, rough endoplasmic reticulum, and nuclear and plasma membranes. On the contrary, mice accumulated in large lipid droplets, and smooth reticulum fractions in addition to nuclear and plasma membranes. These results show that the squalene cellular localization may change according to experimental setting and be a starting point to characterize the mechanisms involved in the protective action of dietary squalene in several pathologies.
KeywordsSqualene The liver Subcellular fractions Steatosis
This research was supported by grants from the Spanish Ministerio de Economía y Competitividad, Agencia Estatal de Investigación—European Regional Development Fund (SAF2013-41651-R and SAF2016-75441-R) and the European Social Fund—Gobierno de Aragón (B-69). CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN, CB06/03/1012) is an initiative of ISCIII.
Compliance with ethical standards
Animals were handled and killed observing guidelines (Directive 2010/63/UE) from the European Union for care and use of laboratory animals in research, and the protocols were approved by the Ethics Committee for Animal Research of the University of Zaragoza.
Conflicts of interest
The authors declare that they have no conflict of interest.
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