Localization of juxtacrine factor ephrin-B2 in pituitary stem/progenitor cell niches throughout life

Cell Tissue Res. 2015 Mar;359(3):755-66. doi: 10.1007/s00441-014-2054-y. Epub 2014 Dec 6.

Abstract

We have recently reported that Sox2-expressing pituitary stem/progenitor cells contact each other via a tight-junction protein CAR to form stem/progenitor cell niches in the marginal cell layer facing the lumen and in the clusters scattered in the parenchyma of the anterior lobe. However, the microenvironment of the niche for the maintenance of stem cell function in the pituitary remains obscure. In this study of pituitary stem/progenitor cell niches, we have attempted to identify the expression of juxtacrine factor ephrin and its receptor. We have found that ephrin-B2 is expressed in the pituitary throughout development but changes its localization pattern. Notably, in the adult pituitary, ephrin-B2 immuno-signals occur in SOX2-, E-cadherin-, and CAR-triple-positive stem/progenitor cells in the niches. Our data suggest that ephrin-B2 signaling has an important role in the formation of pituitary stem/progenitor cell niches and in pituitary organogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism
  • Animals
  • Biomarkers / metabolism
  • Cadherins / metabolism
  • Coxsackie and Adenovirus Receptor-Like Membrane Protein
  • Ephrin-B2 / genetics
  • Ephrin-B2 / metabolism*
  • Gene Expression Regulation, Developmental
  • Green Fluorescent Proteins / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Hormones / metabolism
  • Male
  • Pituitary Gland / cytology*
  • Pituitary Gland / embryology
  • Pituitary Gland / growth & development
  • Protein Transport
  • Rats
  • S100 Calcium Binding Protein beta Subunit / genetics
  • S100 Calcium Binding Protein beta Subunit / metabolism
  • SOXB1 Transcription Factors / metabolism
  • Stem Cell Niche*
  • Stem Cells / cytology
  • Stem Cells / metabolism*

Substances

  • Biomarkers
  • Cadherins
  • Coxsackie and Adenovirus Receptor-Like Membrane Protein
  • Ephrin-B2
  • Homeodomain Proteins
  • Hormones
  • Prophet of Pit-1 protein
  • S100 Calcium Binding Protein beta Subunit
  • SOXB1 Transcription Factors
  • Green Fluorescent Proteins