Squalene ameliorates atherosclerotic lesions through the reduction of CD36 scavenger receptor expression in macrophages

Authors

  • Sergio Granados-Principal,

    1. Department of Biochemistry and Molecular Biology II, University of Granada, Granada, Spain
    2. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
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  • Jose L. Quiles,

    1. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
    2. Department of Physiology, University of Granada, Granada, Spain
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  • Cesar L. Ramirez-Tortosa,

    1. Service of Anatomy Pathological, Complejo Hospitalario Ciudad de Jaen, Jaen, Spain
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  • Julio Ochoa-Herrera,

    1. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
    2. Department of Physiology, University of Granada, Granada, Spain
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  • Patricia Perez-Lopez,

    1. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
    2. Department of Physiology, University of Granada, Granada, Spain
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  • Mario Pulido-Moran,

    1. Department of Biochemistry and Molecular Biology II, University of Granada, Granada, Spain
    2. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
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  • MCarmen Ramirez-Tortosa

    Corresponding author
    1. “José Mataix” Institute of Nutrition and Food Technology. Biomedical Research Centre, University of Granada, Granada, Spain
    • Department of Biochemistry and Molecular Biology II, University of Granada, Granada, Spain
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Correspondence: Dr. MCarmen Ramirez-Tortosa, Instituto de Nutrición y Tecnología de Alimentos “José Mataix Verdú”, Universidad de Granada, Centro de Investigación Biomédica, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento s/n, 18100-Granada, Granada, Spain

E-mail: mramirez@ugr.es

Fax: +34-958819132

Abstract

Scope

Anti-atherogenic features of olive oil (OO) have been attributed, in part, to minor compounds, via diverse mechanisms, although its effects on the CD36 receptor have not been examined. We investigated the effects of minor compounds of OO (squalene (SQ), tyrosol (Tyr) and hydroxytyrosol (OH-Tyr)), on the expression of the CD36 receptor, as well as on monocyte/macrophage differentiation and proliferation.

Methods and results

U937 monocytic cells and macrophages (obtained with 10 nM phorbol-myristate-acetate) were exposed to Tyr, OH-Tyr or SQ at 0, 10, 75 and 200 μM with/without native or oxidised LDL(oxLDL). Flow cytometry was used to achieve the expression of CD36 in both cell types exposed to oxLDL plus antioxidants, as well as the inhibition of monocyte/macrophage differentiation after oxLDL and apoptosis. SQ caused a dose-dependent reduction of CD36 in the presence of native and moderate LDL in monocytes and macrophages. Phenotype-dependent cytotoxic and antiproliferative effects were found for OH-Tyr (p < 0.05), while SQ affected neither monocytes nor macrophages (p < 0.01).

Conclusion

SQ does not prevent monocyte migration and activation into macrophages, but it would inhibit oxLDL uptake by macrophages, by reducing CD36 expression. This study provides new data about the role of the components of OO in the prevention of atherosclerosis.

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