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Spotlighted Research

In a review paper published in Nature, HSCI Scientific Co-Director David Scadden explores the interplay between stem cells and their niche, and how this relationship sustains tissues and its role in the design of stem cell therapies.

Title: The Stem-Cell Niche as an Entity of Action
Author: David T. Scadden, MD

Abstract:

Stem-cell populations are established in 'niches' - specific anatomic locations that regulate how they participate in tissue generation, maintenance and repair. The niche saves stem cells from depletion, while protecting the host from over-exuberant stem-cell proliferation. It constitutes a basic unit of tissue physiology, integrating signals that mediate the balanced response of stem cells to the needs of organisms. Yet the niche may also induce pathologies by imposing aberrant function on stem cells or other targets. The interplay between stem cells and their niche creates the dynamic system necessary for sustaining tissues, and for the ultimate design of stem-cell therapeutics.

Figure 1

Refining elements necessary for an adult stem-cell niche. (a) Early studies provided evidence that heterologous cell types created a three-dimensional structure in which stem cells reside. (b) Recent data raises the possibility that a regulatory microenvironment might include stem cells simply resident on the basement membrane with homologous cellÐcell interactions. Stem cells are shown in deep green and more mature offspring are represented by a lighter shade.

Figure 3

Inputs feeding back on stem-cell function in the niche. Elements of the local environment that participate in regulating the system of a stem cell in its tissue state are depicted. These include the constraints of the architectural space, physical engagement of the cell membrane with tethering molecules on neighbouring cells or surfaces, signalling interactions at the interface of stem cells and niche or descendent cells, paracrine and endocrine signals from local or distant sources, neural input and metabolic products of tissue activity.

Scadden DT. The stem-cell niche as an entity of action. Nature. 2006 Jun 29;441(7097):1075-9. Read Abstract.

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The Harvard Stem Cell Institute is a scientific collaborative established to fulfill the promise of stem cell biology as the basis for cures and treatments for a wide range of chronic medical conditions.

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