Atherosclerosis is a process of imbalanced lipid metabolism in the vascular walls. The underlying pathology mainly involves the deposition of oxidized lipids in the endothelium and the accumulation of cholesterol in macrophages. Macrophages export excessive cholesterol (cholesterol efflux) through ATP-binding cassette transporter A1 (ABCA1) to counter the progression of atherosclerosis. We synthesized novel chalcone derivatives and assessed their effects and the underlying mechanisms on ABCA1 expression in macrophages. Human THP-1 macrophages were treated with synthetic chalcone derivatives for 24 h. In Western blot and flow cytometry analyses, a chalcone derivative, (E)-1-(3,4-diisopropoxyphenyl)-3-(4-isopropoxy-3-methoxyphenyl)prop- 2-en-1-one (1m), was observed to significantly enhance ABCA1 protein expression in THP-1 cells (10 µM, 24 h). Levels of mRNA of ABCA1 and liver X receptor alpha (LXRα) were quantified using a real-time quantitative polymerase chain reaction technique and were found to be significantly increased after treatment with the novel chalcone derivative 1m. Several microRNAs, including miR155, miR758, miR10b, miR145, miR33, and miR106b, which functionally inhibit ABCA1 expression were suppressed after treatment with 1m. Collectively, 1m increases ABCA1 expression in human THP-1 macrophages. The mechanisms involve the activation of the LXRα-ABCA1 pathway and suppression of certain microRNAs that regulate ABCA1 expression.

Statins inhibiting 3-hydroxy-3-methylglutaryl-CoA reductase are the standard treatment for hypercholesterolemia in atherosclerotic cardiovascular disease (ASCVD), mediated by inflammatory reactions within vessel walls. Several studies highlighted the pleiotropic effects of statins beyond their lipid-lowering properties. However, few studies investigated the effects of statins on T cell activation. This study evaluated the immunomodulatory capacities of three common statins, pitavastatin, atorvastatin, and rosuvastatin, in activated human T cells. The enzyme-linked immunosorbent assay (ELISA) and quantitative real time polymerase chain reaction (qRT-PCR) results demonstrated stronger inhibitory effects of pitavastatin on the cytokine production of T cells activated by phorbol 12-myristate 13-acetate (PMA) plus ionomycin, including interleukin (IL)-2, interferon (IFN)-γ, IL-6, and tumor necrosis factor α (TNF-α). Molecular investigations revealed that pitavastatin reduced both activating protein-1 (AP-1) DNA binding and transcriptional activities. Further exploration showed the selectively inhibitory effect of pitavastatin on the signaling pathways of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK), but not c-Jun N-terminal kinase (JNK). Our findings suggested that pitavastatin might provide additional benefits for treating hypercholesterolemia and ASCVD through its potent immunomodulatory effects on the suppression of ERK/p38/AP-1 signaling in human T cells.