title: Lack of telomerase activity in human mesenchymal stem cells.
abstract: Telomerase activity and telomere maintenance have been associated with immortality in tumor and embryonic stem cells. Whereas most normal somatic cells are telomerase negative, low levels of this enzyme have been found in adult stem cells from the skin, gut and the hematopoietic system. Here, we show that telomerase activity is not detectable in human mesenchymal stem cells (hMSCs), which have the phenotype SH2+, SH3+, SH4+, CD29+, CD44+, CD14-, CD34- and CD45-, and have the capacity to differentiate into adipocytes, chondrocytes and osteoblasts. These data suggest that hMSCs have a different telomere biology compared to other adult stem cells. Alternatively, true mesenchymal stem cells might be a very rare subpopulation that have a detection level that is below the sensitivity of the TRAP assay.
authors.affiliation: Department of Hematology/Oncology, Freiburg University Medical Center, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zimmermann
authors.forename: M
authors.initials: M
authors.lastname: Voss
authors.forename: S
authors.initials: S
authors.lastname: Kaiser
authors.forename: U
authors.initials: U
authors.lastname: Kapp
authors.forename: C F
authors.initials: CF
authors.lastname: Waller
authors.forename: U M
authors.initials: UM
authors.lastname: Martens
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D001854:Bone Marrow Cells / Q000201:enzymology; D002454:Cell Differentiation; D006801:Humans; D016130:Immunophenotyping; D008648:Mesoderm / Q000166:cytology*; D013234:Stem Cells / Q000201:enzymology*; D019098:Telomerase / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D019098:Telomerase