ABSTRACT
Adult stem cells are responsible for tissue integrity and are able to maintain tissue homeostasis by generating suffi cient numbers of functional mature cells. At the same time, stem cells maintain their own numbers to ensure tissue functionality for the lifetime of an organism. Proper functioning of tissue stem cells is of great relevance to prevent age-associated diseases, which will become more prevalent as the general population in many societies is rapidly aging. Tissue specifi c stem cells have been identifi ed and isolated on the basis of cell surface markers and are functionally characterized in numerous assays (Bhatia et al., 1997; Li et al., 1998; Shackleton et al., 2006; Spangrude et al., 1988). Most tissue stem cells were shown to lose functionality upon aging of the organism. The mechanism for age-dependent stem cell decline is largely unknown, although several potential reasons have been suggested. This chapter will summarize current knowledge on aging of hematopoietic stem cells and provide some possible
Laboratory of Ageing Biology and Stem Cells, European Research Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. *Corresponding author: r.p.van.os@umcg.nl
List of abbreviations after the text.
