An important new research article appeared yesterday, in the
online edition of Future Medicine: Spontaneous reversal of the
developmental aging of normal human cells following
transcriptional reprogramming. The study is important because it
contradicts an important earlier assumption about induced
pluripotent stem cells (iPSCs). It contradicts the assumption
that reverting a cell to iPSC status restores the expression of
telomerase and telomere length to equivalent embryonic stem cell
length. (Note: hiPSCs stands for human iPSCs, hESCs stands for
human embryonic stem cells) In my February 2010 blog post IPSCs,
telomerase, and closing the loop in the stem cell supply chain I
related “The 2009 study Telomeres Acquire Embryonic Stem Cell
Characteristics in Induced Pluripotent Stem Cells was important
in that it showed that reversion of cells to iPSC status fully
restores telomerase activity to iPSCs, equivalent to that in
embryonic stem cells (ESCs). “We show here that telomeres are
elongated in iPS cells compar