1. Academic Validation
  2. Pitavastatin inhibits remnant lipoprotein-induced macrophage foam cell formation through ApoB48 receptor-dependent mechanism

Pitavastatin inhibits remnant lipoprotein-induced macrophage foam cell formation through ApoB48 receptor-dependent mechanism

  • Arterioscler Thromb Vasc Biol. 2005 Feb;25(2):424-9. doi: 10.1161/01.ATV.0000152632.48937.2d.
Akio Kawakami 1 Mariko Tani Tsuyoshi Chiba Katsumasa Yui Shohei Shinozaki Katsuyuki Nakajima Akira Tanaka Kentaro Shimokado Masayuki Yoshida
Affiliations

Affiliation

  • 1 Department of Geriatrics and Vascular Medicine, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
Abstract

Objective: Atherogenic remnant lipoproteins (RLPs) are known to induce foam cell formation in macrophages in vitro and in vivo. We examined the involvement of apoB48 receptor (apoB48R), a novel receptor for RLPs, in that process in vitro and its potential regulation by pitavastatin.

Methods and results: THP-1 macrophages were incubated in the presence of RLPs (20 mg Cholesterol/dL, 24 hours) isolated from hypertriglyceridemic subjects. RLPs significantly increased intracellular Cholesterol ester (CE) and triglyceride (TG) contents (4.8-fold and 5.8-fold, respectively) in the macrophages. Transfection of THP-1 macrophages with short interfering RNA (siRNA) against apoB48R significantly inhibited RLP-induced TG accumulation by 44%. When THP-1 macrophages were pretreated with pitavastatin (5 micromol/L, 24 hours), the expression of apoB48R was significantly decreased and RLP-induced TG accumulation was reduced by 56%. ApoB48R siRNA also inhibited TG accumulation in THP-1 macrophage induced by beta-very-low-density lipoprotein derived from apoE-/- mice by 58%, supporting the notion that apoB48R recognizes and takes-up RLPs in an apoE-independent manner.

Conclusions: RLPs induce macrophage foam cell formation via apoB48R. Pitavastatin inhibits RLP-induced macrophage foam cell formation. The underlying mechanism involves, at least in part, inhibition of apoB48R-dependent mechanism. Our findings indicate a potential role of apoB48R in atherosclerosis. RLPs induced macrophage foam cell formation via apoB48R. Pitavastatin inhibited RLP-induced macrophage foam cell formation, at least in part, via inhibition of apoB48R expression. Our findings indicate a potential role of apoB48R in atherosclerosis.

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