Adult stem cell niches: cellular and molecular components.
As stem cells (SCs) in adult organs continue to be identified and characterized, it becomes clear that their survival, quiescence, and activation depend on specific signals in their microenvironment, or niche. Although adult SCs of diverse tissues differ by their developmental origin, cycling activity, and regenerative capacity, there appear to be conserved similarities regarding the cellular and molecular components of the SC niche. Interestingly, many organs house both slow-cycling and fast-cycling SC populations, which rely on the coexistence of quiescent and inductive niches for proper regulation. In this review we present a general definition of adult SC niches in the most studied mammalian systems. We further focus on dissecting their cellular organization and on highlighting recently identified key molecular regulators. Finally, we detail the potential involvement of the SC niche in tissue degeneration, with a particular emphasis on aging and cancer.
Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA.
Amélie
A
Rezza
Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA.
Rachel
R
Sennett
Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, USA; Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, USA. Electronic address: michael.rendl@mssm.edu.
Michael
M
Rendl
D000328:Adult; D053687:Adult Stem Cells / Q000502:physiology*; D000375:Aging / Q000502:physiology*; D019898:Autocrine Communication / Q000502:physiology*; D060833:Cellular Microenvironment / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D008954:Models, Biological; D009132:Muscles / Q000166:cytology; D009369:Neoplasms / Q000503:physiopathology*; D009417:Nerve Tissue / Q000166:cytology; D015398:Signal Transduction / Q000502:physiology*; D013093:Spermatogonia / Q000166:cytology
Activation; Adult stem cells; Quiescence; Self-renewal; Signaling; Stem cell niche