周縁組織における昼夜時間のリセットは,グルココルチコイドシグナル伝達によって行われます
A Balsalobre1, S A Brown, L Marcacci
1Département de Biologie Moléculaire, Sciences II, Université de Genève, 30 Quai Ernest Ansermet, CH-1211 Genève, Switzerland.
まとめ
デキサメタゾンは,グルココルチコイドのアナログであり,哺乳類の周周周日時計をリセットしますが,中央脳のペースメーカーはリセットされません. 周辺の時計は,中央時計とは異なり,一日中フェーズリセットに反応します.
科学分野:
- クロノバイオロジーはクロノバイオロジーを用います.
- エンドクリノロジー エンドクリノロジー
- 分子生物学は分子生物学である.
背景:
- 哺乳類の昼夜リズムは,上下神経核 (SCN) にある中央ペースメーカーと,様々な組織に存在する外周振動器によって調節される.
- 中央時計と外周時計の異なる調節を理解することは,全体的な昼間ホメオスタシスを理解するために不可欠です.
研究 の 目的:
- 周辺組織と中央SCNにおける昼間遺伝子発現に対するグルココルチコイドアナログデキサメタゾンの効果を調査する.
- デキサメタゾンへの反応として,周辺時計のフェーズリセット特性を特徴づける.
主な方法:
- 培養されたラット-1線維芽細胞は,昼間の遺伝子発現に対するデキサメタゾンの影響を評価するために使用されました.
- 健全な動物は,肝臓,腎臓,心臓組織,SCNニューロンにおける相変化を評価するためにデキサメタゾンで治療した.
- 外部時計のフェーズシフト応答曲線が生成されました.
主要な成果:
- デキサメタゾンは,培養された線維芽細胞における昼夜間の遺伝子発現を誘導した.
- デキサメタゾンは,外周組織 (肝臓,腎臓,心臓) で一時的な相変化を引き起こしたが,SCNニューロンではそうではない.
- 周辺日経振動器は,一日中フェーズリセットに対する持続的な反応を示した.
結論:
- デキサメタゾンのようなグルココルチコイドホルモンは,中央および周辺の昼間の時計を差異的に調節することができます.
- 周辺の時計は,中央SCNの時計と比較して,フェーズリセット刺激に対するより広範な感受性を示す.
- これらの発見は,周辺日経振動器の独特の可塑性を強調しています.
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