Sensory neuron-derived TAFA4 promotes macrophage tissue repair functions

Nature. 2021 Jun;594(7861):94-99. doi: 10.1038/s41586-021-03563-7. Epub 2021 May 19.

Abstract

Inflammation is a defence response to tissue damage that requires tight regulation in order to prevent impaired healing. Tissue-resident macrophages have a key role in tissue repair1, but the precise molecular mechanisms that regulate the balance between inflammatory and pro-repair macrophage responses during healing remain poorly understood. Here we demonstrate a major role for sensory neurons in promoting the tissue-repair function of macrophages. In a sunburn-like model of skin damage in mice, the conditional ablation of sensory neurons expressing the Gαi-interacting protein (GINIP) results in defective tissue regeneration and in dermal fibrosis. Elucidation of the underlying molecular mechanisms revealed a crucial role for the neuropeptide TAFA4, which is produced in the skin by C-low threshold mechanoreceptors-a subset of GINIP+ neurons. TAFA4 modulates the inflammatory profile of macrophages directly in vitro. In vivo studies in Tafa4-deficient mice revealed that TAFA4 promotes the production of IL-10 by dermal macrophages after UV-induced skin damage. This TAFA4-IL-10 axis also ensures the survival and maintenance of IL-10+TIM4+ dermal macrophages, reducing skin inflammation and promoting tissue regeneration. These results reveal a neuroimmune regulatory pathway driven by the neuropeptide TAFA4 that promotes the anti-inflammatory functions of macrophages and prevents fibrosis after tissue damage, and could lead to new therapeutic perspectives for inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Survival
  • Cytokines / deficiency
  • Cytokines / metabolism*
  • Disease Models, Animal
  • Female
  • Fibrosis / etiology
  • Fibrosis / metabolism
  • Fibrosis / pathology
  • Fibrosis / prevention & control
  • Inflammation / etiology
  • Inflammation / metabolism
  • Inflammation / pathology
  • Inflammation / prevention & control
  • Interleukin-10 / biosynthesis
  • Interleukin-10 / metabolism
  • Macrophages / metabolism*
  • Macrophages / radiation effects
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Regeneration*
  • Sensory Receptor Cells / metabolism*
  • Sensory Receptor Cells / radiation effects
  • Skin / pathology
  • Skin / radiation effects
  • Sunburn / complications
  • Sunburn / etiology
  • Sunburn / metabolism
  • Sunburn / pathology
  • Ultraviolet Rays / adverse effects
  • Wound Healing*

Substances

  • Cytokines
  • Membrane Proteins
  • TAFA4 protein, mouse
  • TIM-4 protein, mouse
  • Interleukin-10