Related Experiment Video
Updated: Aug 15, 2026
Simultaneous Study of the Recruitment of Monocyte Subpopulations Under Flow In Vitro
Published on: November 26, 2018
Lovastatin reduces expression of the combined adhesion and scavenger receptor CD36 in human monocytic cells
1Institut für Prophylaxe Der Kreislaufkrankheiten, Ludwig-Maximilians-Universität München, Germany.
Insights
Lovastatin reduces CD36 expression in monocytes, decreasing oxidized LDL uptake and foam cell formation. This cholesterol synthesis inhibition offers a new therapeutic avenue for atherosclerosis by impacting monocyte adhesion.
Area of Science:
- Biochemistry
- Immunology
- Cardiovascular Research
Background:
- CD36 acts as a scavenger receptor for oxidized low-density lipoproteins (oxLDL), potentially mediating monocyte adhesion and foam cell formation.
- Understanding CD36 regulation in monocytes is crucial for developing therapies against atherosclerosis.
Purpose of the Study:
- To investigate the regulation of CD36 expression in monocytic cells under conditions of cholesterol depletion and overload.
- To compare CD36 regulation with the native low-density lipoprotein receptor (LDL-R) under similar conditions.
Main Methods:
- Human monocytic U937 cells were treated with lovastatin, native LDL, and oxLDL.
- Gene and protein expression of lipoprotein receptors were quantified using quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS).
Main Results:
- Lovastatin significantly reduced CD36 RNA and protein levels in a dose-dependent manner, decreasing oxLDL binding.
- Unlike LDL-R, CD36 transcription was not affected by native or oxLDL, though protein levels decreased due to oxLDL-induced internalization.
- Mevalonate reversed lovastatin's effects, indicating a link to cholesterol synthesis.
Conclusions:
- Monocyte CD36 expression is downregulated by cholesterol synthesis inhibition (lovastatin) but not by substrate overexposure, contrasting with LDL-R regulation.
- Lovastatin's suppression of CD36 represents a novel pharmacological action that may reduce monocyte adhesion and foam cell formation, contributing to its anti-atherosclerotic benefits.
Abstract:
The thrombospondin and collagen receptor CD36 was recently found to function, also, as a dominating scavenger receptor for oxidized low-density lipoproteins (oxLDL). Thus, CD36 might be a key factor in monocyte adhesion and foam cell formation. We, therefore, studied CD36 expression in monocytic cells under conditions of cholesterol depletion and overload. Human monocytic U937 cells were cultured under control conditions and in the presence of lovastatin, native, and oxLDL. The expression of lipoprotein receptors was measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS). In sharp contrast to the feedback-controlled ApoB100 specific receptor for native low-density lipoprotein (LDL-R), CD36 expression was significantly reduced by lovastatin in a dose-dependent manner, both at the RNA and protein level, resulting in decreased cellular oxLDL binding. The addition of mevalonate completely reversed lovastatin effects, whereas excess LDL was only partially effective. Similarly to native LDL, oxLDL reduced LDL-R transcription, but did not affect CD36 transcription. CD36 protein surface expression fell, however, due to internalization of CD36 loaded with oxLDL. In summary, monocytic expression of CD36, in contrast to the native LDL-R, is reduced by cholesterol synthesis inhibition and not by feedback inhibition from substrate overexposure. CD36 suppression is a new pharmacological action of lovastatin that may contribute to its clinical benefit by attenuating monocyte adhesion and foam cell formation, key steps in atherosclerosis.
