Smooth muscle cell-derived Cxcl12 directs macrophage accrual and sympathetic innervation to control thermogenic adipose tissue

Cell Rep. 2024 May 28;43(5):114169. doi: 10.1016/j.celrep.2024.114169. Epub 2024 Apr 27.

Abstract

Sympathetic innervation of brown adipose tissue (BAT) controls mammalian adaptative thermogenesis. However, the cellular and molecular underpinnings contributing to BAT innervation remain poorly defined. Here, we show that smooth muscle cells (SMCs) support BAT growth, lipid utilization, and thermogenic plasticity. Moreover, we find that BAT SMCs express and control the bioavailability of Cxcl12. SMC deletion of Cxcl12 fosters brown adipocyte lipid accumulation, reduces energy expenditure, and increases susceptibility to diet-induced metabolic dysfunction. Mechanistically, we find that Cxcl12 stimulates CD301+ macrophage recruitment and supports sympathetic neuronal maintenance. Administering recombinant Cxcl12 to obese mice or leptin-deficient (Ob/Ob) mice is sufficient to boost macrophage presence and drive sympathetic innervation to restore BAT morphology and thermogenic responses. Altogether, our data reveal an SMC chemokine-dependent pathway linking immunological infiltration and sympathetic innervation as a rheostat for BAT maintenance and thermogenesis.

Keywords: CP: Immunology; CP: Metabolism; Cxcl2; brown adipocytes; macrophage; smooth muscle cells; sympathetic innervation; thermogenesis.

MeSH terms

  • Adipose Tissue, Brown* / innervation
  • Adipose Tissue, Brown* / metabolism
  • Animals
  • Chemokine CXCL12* / metabolism
  • Energy Metabolism
  • Macrophages* / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Myocytes, Smooth Muscle* / metabolism
  • Obesity / metabolism
  • Obesity / pathology
  • Sympathetic Nervous System* / metabolism
  • Sympathetic Nervous System* / physiology
  • Thermogenesis*

Substances

  • Chemokine CXCL12
  • Cxcl12 protein, mouse