How the stem cell niche never dies
[NEWS 2010-12-03] Stem cells are enclosed by special protective cells in what is known as a stem cell niche in the surrounding tissue. A new paper from Karolinska Institutet, published in the scientific journal Cell Stem Cell, now demonstrates how the stem cell niche in the adult mouse brain can be maintained for life - in a way that is completely different from stem cells.
Stem cells give rise to new cells in many organs throughout a body's lifespan. Besides producing different types of specialised cell, stem cells also produce new stem cells. Without this property of duplication, the bodys store of stem cells would soon be depleted. This self-renewal capacity is the key to how stem cells can serve as a kind of cellular perpetual motion machine, constantly generating new cells.
The self-renewal capacity is attributable not only to the unique properties of stem cells but also to the unique characteristics of their environment. Stem cells are enclosed by special protective cells in what is known as a stem cell niche in the surrounding tissue. Although a great deal of research has been devoted to the unique properties of stem cells, nothing has been known about how the stem cell niche is maintained. Stem cells have a unique ability to divide an almost infinite number of times to produce new copies of themselves. This is not the case, however, for the stem cell niche cells, which, as the present study by Professor Jonas Frisén and his colleagues at Karolinska Institutet and the University of Texas Southwestern Medical Center shows, do not renew themselves; instead, different types of niche cell can be transformed here into the type that has been lost in order to maintain the structure. They also show how the transformation of different niche cells is regulated at a molecular level.
The study contributes to science's understanding of how stem cells in the adult body are able to perpetually produce new cells. Stem cells are used clinically in the treatment of numerous diseases, and the hope is that completely new types of therapy can be developed that exploit the ability of stem cells to replace lost cells.
EphB Signaling Controls Lineage Plasticity of Adult Neural Stem Cell Niche Cells
Cell Stem Cell, 3 December 2010; Volume 7; Issue 6