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Author Yamada, Hodaka ♦ Umemoto, Tomio ♦ Kawano, Mikihiko ♦ Kawakami, Masanobu ♦ Kakei, Masafumi ♦ Momomura, Shin-ichi ♦ Ishikawa, San-e. ♦ Hara, Kazuo
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ APOLIPOPROTEINS ♦ CARBOXYLIC ACIDS ♦ INFLAMMATION ♦ INHIBITION ♦ LYMPHOKINES ♦ METABOLIC DISEASES ♦ RECEPTORS ♦ TRANSLOCATION
Abstract Saturated fatty acids (SFAs) activate toll-like receptor 4 (TLR4) signal transduction in macrophages and are involved in the chronic inflammation accompanying obesity. High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) produce anti-inflammatory effects via reverse cholesterol transport. However, the underlying mechanisms by which HDL and apoA-I inhibit inflammatory responses in adipocytes remain to be determined. Here we examined whether palmitate increases the translocation of TLR4 into lipid rafts and whether HDL and apoA-I inhibit inflammation in adipocytes. Palmitate exposure (250 μM, 24 h) increased interleukin-6 and tumor necrosis factor-α gene expressions and translocation of TLR4 into lipid rafts in 3T3-L1 adipocytes. Pretreatment with HDL and apoA-I (50 μg/mL, 6 h) suppressed palmitate-induced inflammatory cytokine expression and TLR4 translocation into lipid rafts. Moreover, HDL and apoA-I inhibited palmitate-induced phosphorylation of nuclear factor-kappa B. HDL showed an anti-inflammatory effect via ATP-binding cassette transporter G1 and scavenger receptor class B, member 1, whereas apoA-I showed an effect via ATP-binding cassette transporter A1. These results demonstrated that HDL and apoA-I reduced palmitate-potentiated TLR4 trafficking into lipid rafts and its related inflammation in adipocytes via these specific transporters. - Highlights: • Palmitate induces TLR4 translocation into lipid rafts in 3T3-L1 adipocytes. • Raft disruption by MβCD inhibits lipid raft formation. • HDL and apoA-I inhibit palmitate-induced translocation of TLR4 into lipid rafts. • Anti-inflammatory effects of HDL and apoA-I occur via specific transporters.
ISSN 0006291X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-03-04
Publisher Place United States
Journal Biochemical and Biophysical Research Communications
Volume Number 484
Issue Number 2


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