Grapefruit Flavonoid Naringenin Regulates the Expression of LXRα in THP-1 Macrophages by Modulating AMP-Activated Protein Kinase.
Javier SaenzConsuelo Santa-MaríaMaría Edith Reyes-QuirozIsabel GenizJuan JiménezFrancisco SobrinoGonzalo AlbaPublished in: Molecular pharmaceutics (2018)
The present work investigates the modulation of grapefruit flavonoid naringenin over liver X receptor alpha (LXRα) and its target genes in THP-1 macrophages, focusing on AMP-activated protein kinase (AMPK) implication. Naringenin induced LXRα at mRNA and protein levels besides influencing the expression of LXRα target genes ABCA1, ABCG1 (ATP-binding cassette A1 and G1), and SREBP1c (sterol response element binding protein 1c) in THP-1 macrophages. The increased LXRα mRNA and protein expression was reverted when AMPK was inhibited by its chemical inhibitor, compound C or by transfection with AMPK α1 and α2 siRNA. Naringenin treatments were also able to promote reverse cholesterol transport in THP-1 cells, which is in line with the increase in the ABCA1 and ABCG1 expression found. Treatments with this flavonoid also inhibited cell migration in THP-1 cells. In conclusion, LXRα and its target genes are up-regulated by naringenin in an AMPK dependent manner in human macrophages. The enhancement in the expression of genes involved in cholesterol efflux may reveal a new mechanism by which this polyphenol can prevent atherosclerosis and foam cell progression.
Keyphrases
- protein kinase
- binding protein
- poor prognosis
- induced apoptosis
- cell migration
- skeletal muscle
- cell cycle arrest
- endothelial cells
- cardiovascular disease
- stem cells
- cell death
- small molecule
- endoplasmic reticulum stress
- oxidative stress
- cell therapy
- mesenchymal stem cells
- cancer therapy
- pi k akt
- dna binding
- cancer stem cells