Tcf3 expression marks both stem and progenitor cells in multiple epithelia

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Molecular Biology

Background:

• The Lef/Tcf-family transcription factor Tcf3 is crucial for development, stem cell function, and malignancy.
• Previous studies suggested Tcf3 mediates self-renewal and maintains an undifferentiated state in skin stem and progenitor cells.

Purpose of the Study:

• To investigate the distribution and behavior of Tcf3-expressing cells in various adult tissues.
• To elucidate the role of Tcf3 in stem cell dynamics and differentiation in postnatal epithelia.

Main Methods:

• Utilized a novel Tcf3-CreER knock-in mouse model for lineage tracing.
• Examined Tcf3-expressing cell populations in dorsal skin, paw skin, tongue, and esophagus.

Main Results:

• Confirmed Tcf3-expressing cells in the hair follicle bulge are self-renewing stem cells with multilineage potential.
• Identified Tcf3-expressing cells in the basal layer of stratified epithelia, including paw skin, tongue, and esophagus.
• Demonstrated that Tcf3-expressing populations comprise stem cells, transient progenitors, and differentiating cells.

Conclusions:

• Tcf3 plays a role in maintaining stem cell populations in multiple adult epithelial tissues.
• The function of Tcf3 in cell-fate determination is more intricate than previously understood and is influenced by the cellular environment.