The stem-like Stat3-responsive cells of zebrafish intestine are Wnt/β-catenin dependent

Development. 2020 Jun 19;147(12):dev188987. doi: 10.1242/dev.188987.

Abstract

The transcription factor Stat3 is required for proliferation and pluripotency of embryonic stem cells; we have prepared and characterized fluorescent Stat3-reporter zebrafish based on repeats of minimal responsive elements. These transgenic lines mimic in vivo Stat3 expression patterns and are responsive to exogenous Stat3; notably, fluorescence is inhibited by both stat3 knockout and IL6/Jak/STAT inhibitors. At larval stages, Stat3 reporter activity correlates with proliferating regions of the brain, haematopoietic tissue and intestine. In the adult gut, the reporter is active in sparse proliferating cells, located at the base of intestinal folds, expressing the stemness marker sox9b and having the morphology of mammalian crypt base columnar cells; noteworthy, zebrafish stat3 mutants show defects in intestinal folding. Stat3 reporter activity in the gut is abolished with mutation of T cell factor 4 (Tcf7l2), the intestinal mediator of Wnt/β-catenin-dependent transcription. The Wnt/β-catenin dependence of Stat3 activity in the gut is confirmed by abrupt expansion of Stat3-positive cells in intestinal adenomas of apc heterozygotes. Our findings indicate that Jak/Stat3 signalling is needed for intestinal stem cell maintenance and possibly crucial in controlling Wnt/β-catenin-dependent colorectal cancer cell proliferation.

Keywords: Intestine; Stat3; Stem cells; Wnt/β-catenin; Zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified / growth & development
  • Animals, Genetically Modified / metabolism
  • Intestinal Mucosa / metabolism*
  • Intestines / growth & development
  • Intestines / physiology
  • Janus Kinase 1
  • Larva / growth & development
  • Larva / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • SOX9 Transcription Factor / metabolism
  • STAT3 Transcription Factor / antagonists & inhibitors
  • STAT3 Transcription Factor / deficiency
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism*
  • Transcription Factor 7-Like 2 Protein / deficiency
  • Transcription Factor 7-Like 2 Protein / genetics
  • Transcription Factor 7-Like 2 Protein / metabolism
  • Transcription, Genetic / drug effects
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism
  • Wnt Proteins / metabolism
  • Wnt Signaling Pathway* / drug effects
  • Zebrafish / growth & development
  • Zebrafish / metabolism*
  • Zebrafish Proteins / antagonists & inhibitors
  • Zebrafish Proteins / deficiency
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*
  • beta Catenin / metabolism

Substances

  • Protein Kinase Inhibitors
  • SOX9 Transcription Factor
  • STAT3 Transcription Factor
  • Sox9b protein, zebrafish
  • TCF7L2 protein, zebrafish
  • Transcription Factor 7-Like 2 Protein
  • Tumor Suppressor Proteins
  • Wnt Proteins
  • Zebrafish Proteins
  • apc protein, zebrafish
  • beta Catenin
  • stat3 protein, zebrafish
  • Janus Kinase 1