Deletion of SA β-Gal+ cells using senolytics improves muscle regeneration in old mice

Cory M. Dungan, Kevin A. Murach, Christopher J. Zdunek, Zuo Jian Tang, Georgia L. Nolt, Camille R. Brightwell, Zachary Hettinger, Davis A Englund, Zheng Liu, Christopher S. Fry, Antonio Filareto, Michael Franti, Charlotte A. Peterson

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

Systemic deletion of senescent cells leads to robust improvements in cognitive, cardiovascular, and whole-body metabolism, but their role in tissue reparative processes is incompletely understood. We hypothesized that senolytic drugs would enhance regeneration in aged skeletal muscle. Young (3 months) and old (20 months) male C57Bl/6J mice were administered the senolytics dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi-weekly for 4 months. Tibialis anterior (TA) was then injected with 1.2% BaCl2 or PBS 7- or 28 days prior to euthanization. Senescence-associated β-Galactosidase positive (SA β-Gal+) cell abundance was low in muscle from both young and old mice and increased similarly 7 days following injury in both age groups, with no effect of D+Q. Most SA β-Gal+ cells were also CD11b+ in young and old mice 7- and 14 days following injury, suggesting they are infiltrating immune cells. By 14 days, SA β-Gal+/CD11b+ cells from old mice expressed senescence genes, whereas those from young mice expressed higher levels of genes characteristic of anti-inflammatory macrophages. SA β-Gal+ cells remained elevated in old compared to young mice 28 days following injury, which were reduced by D+Q only in the old mice. In D+Q-treated old mice, muscle regenerated following injury to a greater extent compared to vehicle-treated old mice, having larger fiber cross-sectional area after 28 days. Conversely, D+Q blunted regeneration in young mice. In vitro experiments suggested D+Q directly improve myogenic progenitor cell proliferation. Enhanced physical function and improved muscle regeneration demonstrate that senolytics have beneficial effects only in old mice.

Original languageEnglish
Article numbere13528
JournalAging Cell
Volume21
Issue number1
DOIs
StatePublished - Jan 2022

Bibliographical note

Funding Information:
The authors would like to thank Jennifer Strange, Kaitlyn Frick, and Savannah Jones for their assistance on this project. This research was supported by NIH grants AG049806 and AG069909 to C.A.P and AG063944 to K.A.M. The Glenn Foundation for Medical Research also provided support for this project.

Funding Information:
The authors would like to thank Jennifer Strange, Kaitlyn Frick, and Savannah Jones for their assistance on this project. This research was supported by NIH grants AG049806 and AG069909 to C.A.P and AG063944 to K.A.M. The Glenn Foundation for Medical Research also provided support for this project.

Publisher Copyright:
© 2021 The Authors. Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.

ASJC Scopus subject areas

  • Aging
  • Cell Biology

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