title: Aging of hematopoietic stem cells: Intrinsic changes or micro-environmental effects?
abstract: During development hematopoietic stem cells (HSCs) expand in number and persist throughout life by undergoing self-renewing divisions. Nevertheless, the hematopoietic system does not escape the negative effects of aging, suggesting that self-renewal is not complete. A fundamental issue in stem cell biology relates to such age-dependent loss of stem cell activity. Both stem cell intrinsic factors and extrinsic factors associated with an aging micro-environment could contribute to aging of the hematopoietic system. Recently, changes in the clonal composition of the HSC compartment during aging have been put forward as a key factor. Here, we discuss these recent developments and speculate how they may be of clinical relevance.
authors.affiliation: Department of Hematology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Carolien M
authors.initials: CM
authors.lastname: Woolthuis
authors.forename: Gerald
authors.initials: G
authors.lastname: de Haan
authors.forename: Gerwin
authors.initials: G
authors.lastname: Huls
mesh_terms: D017668:Age of Onset; D000368:Aged; D000375:Aging / Q000097:blood / Q000276:immunology*; D000818:Animals; D001853:Bone Marrow / Q000254:growth & development; D019070:Cell Lineage; D002999:Clone Cells / Q000166:cytology; D018507:Gene Expression Regulation, Developmental; D006410:Hematopoiesis / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006413:Hematopoietic System / Q000166:cytology / Q000254:growth & development*; D006801:Humans; D007951:Leukemia, Myeloid / Q000453:epidemiology / Q000473:pathology; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D018448:Models, Immunological; D022423:Myeloid Cells / Q000166:cytology; D055153:Stem Cell Niche / Q000502:physiology*; D017154:Stromal Cells / Q000502:physiology