A family business: stem cell progeny join the niche to regulate homeostasis

Abstract

Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.

FOXC1 maintains the hair follicle stem cell niche and governs stem cell quiescence to preserve long-term tissue-regenerating potential

“…Termed the "niche," it not only provides a residence for SCs, but also interacts with SCs to regulate their behavior and properties (3,4). Niche signals can take the form of short-range cues from the immediate neighbors of the SCs, or longer-range signals from the macroenvironment of the organ (5)(6)(7)(8).…”

Tuning of Protein Kinase Circuitry by p38α Is Vital for Epithelial Tissue Homeostasis

“…To replenish cells lost due to normal shedding and injury, intestinal and skin stem cells cycle to produce transit-amplifying cells, which rapidly proliferate and then differentiate into specialized and functionally competent epithelial cells (4). Cells at distinct stages in this process are located in different areas along the villus-crypt axis and in different layers of the stratified epidermis (5). Perturbed epithelial tissue homeostasis leads to a functional deterioration such as disruption of permeability barrier and impaired immune surveillance.…”

Sara endosomes and the asymmetric division of intestinal stem cells

“…The formation of daughter cells with distinct developmental potentials depends on two major mechanisms: the regulation by a stem cell niche and/or the asymmetric distribution of cell fate determinants (Morrison and Spradling, 2008;Hsu and Fuchs, 2012). The unequal segregation of cell fate determinants is achieved by several processes: (1) the polarization of the mother cell; (2) the orientation of the mitotic spindle with respect to the polarity axes of the mother cell; and (3) the asymmetric partitioning of signalling molecules (reviewed by Fürthauer and González-Gaitán, 2009a).…”