JCI Insight (Oct 2022)

Macrophage TGF-β signaling is critical for wound healing with heterotopic ossification after trauma

  • Nicole K. Patel,
  • Johanna H. Nunez,
  • Michael Sorkin,
  • Simone Marini,
  • Chase A. Pagani,
  • Amy L. Strong,
  • Charles D. Hwang,
  • Shuli Li,
  • Karthik R. Padmanabhan,
  • Ravi Kumar,
  • Alec C. Bancroft,
  • Joey A. Greenstein,
  • Reagan Nelson,
  • Husain A. Rasheed,
  • Nicholas Livingston,
  • Kaetlin Vasquez,
  • Amanda K. Huber,
  • Benjamin Levi

Journal volume & issue
Vol. 7, no. 20

Abstract

Read online

Transforming growth factor–β1 (TGF-β1) plays a central role in normal and aberrant wound healing, but the precise mechanism in the local environment remains elusive. Here, using a mouse model of aberrant wound healing resulting in heterotopic ossification (HO) after traumatic injury, we find autocrine TGF-β1 signaling in macrophages, and not mesenchymal stem/progenitor cells, is critical in HO formation. In-depth single-cell transcriptomic and epigenomic analyses in combination with immunostaining of cells from the injury site demonstrated increased TGF-β1 signaling in early infiltrating macrophages, with open chromatin regions in TGF-β1–stimulated genes at binding sites specific for transcription factors of activated TGF-β1 (SMAD2/3). Genetic deletion of TGF-β1 receptor type 1 (Tgfbr1; Alk5), in macrophages, resulted in increased HO, with a trend toward decreased tendinous HO. To bypass the effect seen by altering the receptor, we administered a systemic treatment with TGF-β1/3 ligand trap TGF-βRII-Fc, which resulted in decreased HO formation and a delay in macrophage infiltration to the injury site. Overall, our data support the role of the TGF-β1/ALK5 signaling pathway in HO.

Keywords