WNT-dependent interaction between inflammatory fibroblasts and FOLR2+ macrophages promotes fibrosis in chronic kidney disease

Nat Commun. 2024 Jan 25;15(1):743. doi: 10.1038/s41467-024-44886-z.

Abstract

Chronic kidney disease (CKD) is a public health problem driven by myofibroblast accumulation, leading to interstitial fibrosis. Heterogeneity is a recently recognized characteristic in kidney fibroblasts in CKD, but the role of different populations is still unclear. Here, we characterize a proinflammatory fibroblast population (named CXCL-iFibro), which corresponds to an early state of myofibroblast differentiation in CKD. We demonstrate that CXCL-iFibro co-localize with macrophages in the kidney and participate in their attraction, accumulation, and switch into FOLR2+ macrophages from early CKD stages on. In vitro, macrophages promote the switch of CXCL-iFibro into ECM-secreting myofibroblasts through a WNT/β-catenin-dependent pathway, thereby suggesting a reciprocal crosstalk between these populations of fibroblasts and macrophages. Finally, the detection of CXCL-iFibro at early stages of CKD is predictive of poor patient prognosis, which shows that the CXCL-iFibro population is an early player in CKD progression and demonstrates the clinical relevance of our findings.

MeSH terms

  • Fibroblasts / metabolism
  • Fibrosis
  • Folate Receptor 2* / metabolism
  • Humans
  • Kidney / pathology
  • Macrophages / metabolism
  • Myofibroblasts / metabolism
  • Renal Insufficiency, Chronic* / pathology

Substances

  • FOLR2 protein, human
  • Folate Receptor 2