第801回 生医研セミナー(多階層生体防御システム研究拠点)

今回のセミナーでは、フランス国立保健医学研究所のFrédéric Relaix教授をお招きしてセミナーを開催します。骨格筋分野のトップクラスの研究者です。分野のホットトピックを中心に現況を知る貴重な機会です。皆様、ぜひご来聴ください。

※セミナーは英語で行われます。(Seminar in English)

演題 / Title

Regulation of muscle stem cells quiescence and activation.

演者 / Speaker

Prof. Frédéric Relaix
INSERM U955-E10 IMRB, team “BIOLOGY OF THE NEUROMUSCULAR SYSTEM”, Paris East University, Creteil 94000 FRANCE

日時 / Date

2019年10月28日(月) Oct. 28 (Mon), 2019
17:00~18:00

場所 / Venue

病院キャンパス 総合研究棟 1階 講義室102
以下の地図の33番です。
(http://www.kyushu-u.ac.jp/f/35767/2019hospital_2.pdf)

Lecture Room 102, 1F, Biomedical Research Station, Hospital Campus
No.33 on the following linked map.
(http://www.kyushu-u.ac.jp/f/35768/2019hospital-en_2.pdf)

要 旨 / Abstract

Tissue resident stem cells are maintained quiescent in specialized niches and are capable to repair an organ following injury. Skeletal muscle stem cells, known as muscle satellite cells, are the indispensable cell population responsible of skeletal muscle homeostasis and regeneration in response to injury. In resting condition, the muscle satellite cells are quiescent, and upon niche disruption they rapidly exit quiescence towards an activated proliferative state. However, despite the identification of several molecular regulators of muscle stem cell quiescence and activation, the actual gene regulatory network regulating the initial transition between these cell states remains largely unknown. We implemented a fixation-based protocol to capture cells in their native state, and generated a high-resolution transcriptional map of muscle satellite cells early activation. By time-course analysis, we have captured the earliest transcriptional responses of in vivo quiescent stem cells, and uncovered kinetically co-regulated genetic modules that define a precise sequence of cellular processes that drive cells out of quiescence. Moreover, we found that in response to muscle injury, individual muscle stem cells react asynchronously yet follow a unique activation trajectory. Overall, our study proposes a mechanism of quiescence exit that obeys a precise series of biological function, whereby early proliferation signals act independently of the myogenic signals that occur later. In addition, we identified a muscle stem cell-specific function for the histone chaperone HIRA and Daxx that regulate the deposition of the histone H3 variant H3.3 during replication-independent nucleosome assembly that will be discussed during my presentation.

参考論文 / References

  1. PAX3 confers functional heterogeneity in skeletal muscle stem cell responses to environmental stress.
    Der Vartanian et al. Cell Stem Cell, 2019
  2. Notch/CollagenV/CalcR reciprocal signalling retains muscle stem cells in their niche.
    Baghdadi et al. Nature, 2018

連絡先 / Contact

生体防御医学研究所 トランスクリプトミクス分野
大川 恭行
092(642)4534