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CREBは,核ホルモン受容体PPAR-ガンマを通して,肝臓の脂質代謝を制御する
Stephan Herzig1, Susan Hedrick, Ianessa Morantte
1Peptide Biology Laboratories Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037-1002, USA.
Nature
|November 14, 2003
まとめ
断食は,HES-1経由でPPAR-gammaを抑制するCREBを活性化することによって脂肪合成を抑制します. このメカニズムは,断食中の肝臓脂肪の調節を説明し,インスリン感受性の治療目標を示唆しています.
科学分野:
- メタボリック・レギュレーション
- 分子内分泌学分子内分泌学
- ホルモンのシグナル伝達
背景:
- 禁食は,ホルモンによるヒントによって,肝臓のグルコース排出と脂質分解を誘発する.
- cAMP反応性元素結合タンパク質 (CREB) は,グルコネ原性および脂肪酸酸化経路を活性化します.
- 断食中に肝臓の脂質生成経路を抑制するメカニズムは,ほとんど不明のままである.
研究 の 目的:
- 断食が肝臓の脂質生成を抑制する分子メカニズムを解明する.
- 断食中の脂質代謝の調節におけるCREBとその下流標的の役割を調査する.
主な方法:
- 肝臓のフェノタイプを研究するために,CREB欠乏したマウスを利用しました.
- 核ホルモン受容体 (例:PPAR-gamma) と転写抑制体 (例:HES-1) の遺伝子発現を分析した.
- 断食誘発の脂質代謝におけるHES-1のインビボの役割を調査した.
主要な成果:
- CREB欠乏マウスは,脂肪肝のフェノタイプを示し,PPAR-ガンマ発現が上昇した.
- CREBは,HES-1を刺激することによって,断食中の肝臓PPAR-ガンマ発現を抑制することが判明しました.
- HES-1は,空腹中の脂質代謝の媒介者として,in vivoで作用する.
結論:
- CREBは,断食中のPGC-1誘導とPPAR-ガンマ抑制を調整する.
- これは,インスリンと逆調節ホルモン間の相互作用のための分子基盤を提供します.
- CREBアンタゴニストは,肝臓のインスリン感受性を改善するための治療戦略を表す可能性があります.
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