Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1998 May 1;91(9):3255-62.

Telomerase activity in candidate stem cells from fetal liver and adult bone marrow

J Yui  1 , C P Chiu, P M Lansdorp
Affiliations
  • PMID: 9558381
Free article

Telomerase activity in candidate stem cells from fetal liver and adult bone marrow

J Yui et al. Blood. .
Free article

Abstract

Telomerase is a ribonucleoprotein polymerase that synthesizes telomeric repeats onto the 3' ends of eukaryotic chromosomes. Activation of telomerase may prevent telomeric shortening and correlates with cell immortality in the germline and certain tumor cells. Candidate hematopoietic stem cells (HSC) from adult bone marrow express low levels of telomerase, which is upregulated with proliferation and/or differentiation. To address this issue, we stimulated purified candidate HSC from human adult bone marrow with stem cell factor (SCF), interleukin-3 (IL-3), and Flt3-ligand (FL). After 5 days in culture, activity was detected in total cell extracts from IL-3-, SCF + FL-, SCF + IL-3-, FL + IL-3-, and SCF + IL-3 + FL-stimulated cultures, but not from cells cultured in SCF or FL alone. Within the CD34(+) fraction of the cultured cells, significant activity was found in the CD34(+)CD71(+) fraction. In addition, PKH26 staining confirmed that detectable telomerase activity was present in dividing PKH26(lo) cells, whereas nondividing PKH26(hi) cells were telomerase negative. Because in these experiments no distinction could be made between cycling "candidate" stem cells that had retained or had lost self-renewal properties, fetal liver cells with a CD34(+)CD38(-) phenotype, highly enriched for cycling stem cells, were also examined and found to express readily detectable levels of telomerase activity. Given the replication-dependent loss of telomeric DNA in hematopoietic cells, these observations suggest that the observed telomerase activity in candidate stem cells is either expressed in a minor subset of stem cells or, more likely, is not sufficient to prevent telomere shortening.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

LinkOut - more resources