Hyperlipidemia induces endothelial-derived foam cells in culture

Abstract

Endothelial cells (ECs) play a major role in the pathophysiology of various diseases, conditions in which stress proteins are most probably involved. Both in humans and in experimental models, hyperlipidemia induces early alterations of plasma components that in turn have a profound effect on EC. Activated ECs change their basal characteristics becoming more permeable to lipoproteins, increasing the synthesis of their basal lamina, and express new adhesion molecules; the cells are “activated”. In lesion-prone areas, the ECs are the first cells to experience the impact of hyperlipidemia. In this study, human ECs were activated by exposure to serum from hyperlipidemic human subjects. In this condition, the EC gradually become loaded with lipid droplets and turn into endothelial-derived foam cells. The EC-derived foam cells express adhesion molecules (VCAM-1, VLA-4), show enhanced intracellular Ca²⁺ release, and demonstrate high level of heat shock proteins (Hsp27, Hsp70, and Hsp90). In this study, we bring evidence that the EC-derived foam cells in culture proved to be an useful model to identify the multiple changes induced in activated ECs under hyperlipidemic stress. On the basis of these considerations, future studies using this model system will help to elucidate the molecular basis of the modulator role of molecular chaperones (Hsp) in atherosclerosis under various environmental conditions.

Keywords::

• Atherosclerosis
• endothelial cells
• foam cells
• heat shock proteins
• hyperlipidemic stress

Acknowledgments

The excellent technical assistance of Mariana Pascu and Daniela Rogoz (biochemical techniques) were gratefully acknowledged.

Declaration of interest

The work was supported by the Romanian Academy and grand 346/2007 PN-II-PCE. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.