[Frontiers in Bioscience E2, 78-86, January 1, 2010]

Electronegative LDL induces Fas and modifies gene expression in mononuclear cells

Cristina Bancells1,3, Jose Luis Sanchez-Quesada1, Ragnhild Birkelund1, Jordi Ordonez-Llanos2,3, Sonia Benitez1

1Institut de Recerca, Hospital de la Santa Creu i Sant Pau, 2 Servei de Bioquimica, Hospital de la Santa Creu i Sant Pau, 3Departament de Bioquimica i Biologia Molecular, Universitat Autonoma de Barcelona

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Material and methods
3.1. Lipoproteins and cell isolation
3.2. CodeLinkTM microarrays for gene expression profile analysis
3.3. Real-time RT-PCR
3.4. ELISA experiments
3.5. Statistical analysis
4. Results
4.1. Human whole genome array
4.2. Real-time RT-PCR
4.3. ELISA experiments
5. Discussion
6. Acknowledgments
7. References

1. ABSTRACT

Electronegative LDL (LDL(-)) is a minor modified LDL subfraction that promotes cytokine release by human mononuclear cells. The aim of the current study was to evaluate changes in gene expression induced by LDL(-) versus native LDL in lymphocytes and monocytes. Therefore, mononuclear cells were incubated with these LDL subfractions and their effects on expression in human whole genome were analyzed by gene array. Differential expression of the genes was quantified by real-time RT-PCR. LDL(-) altered the gene expression pattern, particularly of inflammatory genes. LDL(-) down-regulated CD36 and colony-stimulating factor 1 receptor (CSF1R) genes and up-regulated Fas expression and Fas protein on cellular membrane. LDL(-) seemed to promote the alterations in these genes by activation of NF-kB and inhibition of AP1 and PPARG. In conclusion, LDL(-) induced changes in gene expression in monocytes and lymphocytes. Fas up-regulation suggests a proinflammatory action; however, CSF1R and CD36 down-regulation could decrease monocyte differentiation and activation. Therefore, LDL(-) promoted not only inflammatory effects but also counteracting actions in circulating mononuclear cells.