Common Research Facilities
Contact
Medical Institute of Bioregulation, Kyushu University
3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, JAPAN
TEL +81-92-642-6814
FAX +81-92-642-6246

The 801st MIB Seminar
(Joint Usage/Research Center for the Multi-stratified Host Defense System)

[Seminar in English]

Title

Regulation of muscle stem cells quiescence and activation.

Speaker

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

Date

Oct. 28 (Mon), 2019
17:00~18:00

Venue

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)

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.

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

Contact

Division of Transcriptomics, Medical Institute of Bioregulation
Yasuyuki Ohkawa
TEL: 092(642)4534