2023-02-14 スウェーデン王国・カロリンスカ研究所(KI)
◆生物学的プロセスは細胞の概日リズムに依存するため、異なる時間帯に身体を動かすと、身体にさまざまな影響を与える可能性があります。カロリンスカ研究所とコペンハーゲン大学の研究者らは、運動を行う時間帯が脂肪の燃焼にどのような影響を及ぼすかを確かめるため、1日のサイクルの2つのポイント、早期活動期と早期休息期(ヒトではそれぞれ深夜と夕方に相当する)で高強度の運動を行った後のマウスの脂肪組織を調査しました。研究チームは、脂肪代謝に関するさまざまなマーカーを調べ、運動後に脂肪組織で活性化する遺伝子を分析した。
◆研究チームは、早期活動期における運動が、脂肪組織の分解、熱産生(熱を作ること)、脂肪組織のミトコンドリアに関わる遺伝子の発現を増加させ、代謝率が高いことを発見した。これらの効果は、早期活動期に運動したマウスにのみ認められ、食物摂取量とは無関係であった。
◆カロリンスカ研究所分子医学・外科学部門および生理学・薬学部門のJuleen R. Zierath教授は、「この結果は、代謝および脂肪燃焼を高めるという点で、夜遅くの運動よりも朝遅くの運動の方が効果的である可能性を示唆しており、そうであれば、肥満気味の人々にとって価値があることを証明できるかもしれません」と述べています。
<関連情報>
- https://news.ki.se/time-of-day-may-determine-the-amount-of-fat-burned-by-exercise
- https://www.pnas.org/doi/10.1073/pnas.2218510120
マウス脂肪組織における運動後の代謝は時間帯によって左右される Time of day determines postexercise metabolism in mouse adipose tissue
Logan A. Pendergrast,Leonidas S. Lundell,Amy M. Ehrlich,Stephen P. Ashcroft,Milena Schönke,Astrid L. Basse,Anna Krook,Jonas T. Treebak,Lucile Dollet,Juleen R. Zierath
Proceedings of the National Academy of Sciences Published:February 13, 2023
DOI:https://doi.org/10.1073/pnas.2218510120
Significance
Nearly all cells in the body have an internal biological circadian clock that is synchronized by external cues. This machinery forms a transcription–translation feedback loop that anticipates and adapts organismal physiology throughout the 24-h day–night cycle. We tested the hypothesis that timing of energetic stressors that affect glucose and energy homeostasis, namely exercise and feeding status, can differentially influence metabolism in adipose tissue. We found that acute exercise elicits a timing-specific effect on adipose tissue, which is independent of feeding status. Adipose tissue sensitivity to exercise is timing-dependent and modulated in a cell-autonomous fashion, as evidenced by enhanced transcription of metabolic genes in early active phase. Thus, exercise timing may fine-tune adipose metabolism to improve energy homeostasis in cardiometabolic disease.
Abstract
The circadian clock is a cell-autonomous transcription–translation feedback mechanism that anticipates and adapts physiology and behavior to different phases of the day. A variety of factors including hormones, temperature, food-intake, and exercise can act on tissue-specific peripheral clocks to alter the expression of genes that influence metabolism, all in a time-of-day dependent manner. The aim of this study was to elucidate the effects of exercise timing on adipose tissue metabolism. We performed RNA sequencing on inguinal adipose tissue of mice immediately following maximal exercise or sham treatment at the early rest or early active phase. Only during the early active phase did exercise elicit an immediate increase in serum nonesterified fatty acids. Furthermore, early active phase exercise increased expression of markers of thermogenesis and mitochondrial proliferation in inguinal adipose tissue. In vitro, synchronized 3T3-L1 adipocytes showed a timing-dependent difference in Adrb2 expression, as well as a greater lipolytic activity. Thus, the response of adipose tissue to exercise is time-of-day sensitive and may be partly driven by the circadian clock. To determine the influence of feeding state on the time-of-day response to exercise, we replicated the experiment in 10-h-fasted early rest phase mice to mimic the early active phase metabolic status. A 10-h fast led to a similar lipolytic response as observed after active phase exercise but did not replicate the transcriptomic response, suggesting that the observed changes in gene expression are not driven by feeding status. In conclusion, acute exercise elicits timing-specific effects on adipose tissue to maintain metabolic homeostasis.
