Monocyte/Macrophage-derived IGF-1 Orchestrates Murine Skeletal Muscle Regeneration and Modulates Autocrine Polarization

Joanne Tonkin*, Lieve Temmerman, Robert D. Sampson, Enrique Gallego-Colon, Laura Barberi, Daniel Bilbao, Michael D. Schneider, Antonio Musaro, Nadia Rosenthal

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

173 Citations (Web of Science)

Abstract

Insulin-like growth factor 1 (IGF-1) is a potent enhancer of tissue regeneration, and its overexpression in muscle injury leads to hastened resolution of the inflammatory phase. Here, we show that monocytes/macrophages constitute an important initial source of IGF-1 in muscle injury, as conditional deletion of the IGF-1 gene specifically in mouse myeloid cells (?IGF-1 CKO) blocked the normal surge of local IGF-1 in damaged muscle and significantly compromised regeneration. In injured muscle, Ly6C+ monocytes/macrophages and CD206+ macrophages expressed equivalent IGF-1 levels, which were transiently upregulated during transition from the inflammation to repair. In injured ?IGF-1 CKO mouse muscle, accumulation of CD206+ macrophages was impaired, while an increase in Ly6C+ monocytes/macrophages was favored. Transcriptional profiling uncovered inflammatory skewing in ?IGF-1 CKO macrophages, which failed to fully induce a reparative gene program in vitro or in vivo, revealing a novel autocrine role for IGF-1 in modulating murine macrophage phenotypes. These data establish local macrophage-derived IGF-1 as a key factor in inflammation resolution and macrophage polarization during muscle regeneration.
Original languageEnglish
Pages (from-to)1189-1200
JournalMolecular Therapy
Volume23
Issue number7
DOIs
Publication statusPublished - Jul 2015

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