The stem cell niche

Definition

The stem cell niche constitute the local tissue cells and biochemical microenvironment in which stem cells reside, proliferate, and differentiate into mature cells. Stem cells, their daughter cells, and their microenvironment compose an anatomical structure that coordinates processes of normal tissue homeostasis. An appropriate mutual dialog occurs between stem and niche cells in order to accomplish lifelong requirements for differentiated cells. Niche cells create a protecting environment that provides nutrient delivery and sequesters stem cells from a variety of stimuli, including differentiation or apoptotic, that could compromise stem cell reserves. The niche also defenses against excessive stem cell production that could lead to neoplastic cells development. The functional cell niche, through biological and physical signals between the cells that form the niche and the stem cells residing in the niche, guarantee the interaction of cells that control the quiescence of stem cells, symmetric and asymmetric cell division and their differentiation .