Telomeres acquire embryonic stem cell characteristics in induced pluripotent stem cells

2015-01-13

"C:\Users\kurtw_000\Box Sync\DocDR\2014\01-31-2014d1002\Telomeres acquire embryonic stem cell characteristics in induced pluripotent stem cells.pdf"

Abstract
Telomere shortening is associated with organismal
aging. iPS cells have been recently derived from old
patients; however, it is not known whether telomere
chromatin acquires the same characteristics as in
ES cells. We show here that telomeres are elongated
in iPS cells compared to the parental differentiated
cells both when using four (Oct3/4, Sox2, Klf4,
cMyc) or three (Oct3/4, Sox2, Klf4) reprogramming
factors and both from young and aged individuals.
We demonstrate genetically that, during reprogram-
ming, telomere elongation is usually mediated by
telomerase and that iPS telomeres acquire the epige-
netic marks of ES cells, including a low density of tri-
methylated histones H3K9 and H4K20 and increased
abundance of telomere transcripts. Finally, reprog-
ramming ef?ciency of cells derived from increasing
generations of telomerase-de?cient mice shows
a dramatic decrease in iPS cell ef?ciency, a defect
that is restored by telomerase reintroduction.
Together, these results highlight the importance of
telomere biology for iPS cell generation and function-
ality.

some notes
q
-We show here that telomeres are elongated
in iPS cells compared to the parental differentiated
cells both when using four (Oct3/4, Sox2, Klf4,
cMyc) or three (Oct3/4, Sox2, Klf4) reprogramming
factors and both from young and aged individuals.
^wow quite surprising and important
-cMyc Is Dispensable for Telomerase Activation in Mouse
iPS Cells
-Telomere Elongation by Telomerase in iPS Cells
-Impaired iPS Cell Generation from Late-Generation
Terc
/
MEF with Critically Short Telomeres
-Telomeric Heterochromatin in iPS Cells Acquires ES
Cell Features
-Increased Telomere Transcription in iPS Cells
-Telomere Elongation in iPS Cells Derived from Old
Donors
-Generation of mouse iPS cells
-TRF analysis
-MEF: mouse embryonic fibroblast
-Q-FISH analysis
-B1-SINE Cobra Analysis for Global DNA Methylation
-Analysis of Genomic Subtelomeric DNA Methylation
-ChIP Assay

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