Distinct populations of crypt-associated fibroblasts act as signaling hubs to control colon homeostasis

PLoS Biol. 2020 Dec 11;18(12):e3001032. doi: 10.1371/journal.pbio.3001032. eCollection 2020 Dec.

Abstract

Despite recent progress in recognizing the importance of mesenchymal cells for the homeostasis of the intestinal system, the current picture of how these cells communicate with the associated epithelial layer remains unclear. To describe the relevant cell populations in an unbiased manner, we carried out a single-cell transcriptome analysis of the adult murine colon, producing a high-quality atlas of matched colonic epithelium and mesenchyme. We identify two crypt-associated colonic fibroblast populations that are demarcated by different strengths of platelet-derived growth factor receptor A (Pdgfra) expression. Crypt-bottom fibroblasts (CBFs), close to the intestinal stem cells, express low levels of Pdgfra and secrete canonical Wnt ligands, Wnt potentiators, and bone morphogenetic protein (Bmp) inhibitors. Crypt-top fibroblasts (CTFs) exhibit high Pdgfra levels and secrete noncanonical Wnts and Bmp ligands. While the Pdgfralow cells maintain intestinal stem cell proliferation, the Pdgfrahigh cells induce differentiation of the epithelial cells. Our findings enhance our understanding of the crosstalk between various colonic epithelial cells and their associated mesenchymal signaling hubs along the crypt axis-placing differential Pdgfra expression levels in the spotlight of intestinal fibroblast identity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Morphogenetic Proteins / metabolism
  • Cell Differentiation / physiology
  • Cell Proliferation / physiology
  • Colon / metabolism*
  • Colon / physiology
  • Epithelial Cells / metabolism
  • Female
  • Fibroblasts / classification*
  • Fibroblasts / metabolism*
  • Gene Expression Profiling / methods
  • Homeostasis
  • Intestinal Mucosa / metabolism
  • Intestines / physiology
  • Mesoderm / cytology
  • Mesoderm / physiology
  • Mice
  • Mice, Inbred C57BL
  • Signal Transduction
  • Single-Cell Analysis / methods
  • Stem Cells / cytology
  • Transcriptome / genetics

Substances

  • Bone Morphogenetic Proteins

Grants and funding

This work was supported by the Swiss National Science Foundation (http://www.snf.ch/de/Seiten/default.aspx), the University of Zurich Research Priority Program (URPP) “Translational Cancer Research” (https://www.cancer.uzh.ch/en.html) and the Kanton of Zürich (https://www.zh.ch/de.html). MDB is supported by the University of Zürich Forschungskredit Candoc grant Nr. FK-19-074 (https://www.research.uzh.ch/en/funding/phd/fkcandoc.html). TV is supported by Czech Science Foundation grant 18-21466S (https://gacr.cz/en/) and is a fellow of the URPP Translational Cancer Research (https://www.cancer.uzh.ch/en.html). HF is a fellow of the Cancer Research Center Zurich (CRC) (http://www.cancercenter.usz.ch/forschung/cancer-research-center/Seiten/default.aspx). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.