Release of blood stem cells from bone marrow is regulated by brain
through human biological clock
Published: Thursday, 7-Feb-2008
Mount Sinai researchers have discovered that the release of blood
stem cells from bone marrow is regulated by the brain through the
cyclical human biological clock, via adrenergic signals transmitted
by the sympathetic nervous system.
These new findings, published online on the website of the journal
Nature, point out that the harvest of stem cells for transplantation
may be improved by timing it at the peak of their release.
The study describes the mechanisms at the molecular levels in which
signals from the biological clock in the brain are sent via the
sympathetic-
directly to bone marrow stem cell niches. Researchers, using mice as
a model, were able to show the rhythmic release and peak of stem
cells in circulation during the mouse's resting period, and that
changes in the light cycle or an experimental "jet lag" altered the
release patterns. This is the first time a study has demonstrated
that the brain regulates a stem cell niche.
"We don't know why stem cells circulate in the blood but the maximal
release of stem cells in the circulation occurs when the animal is
resting. This argues for a role in regeneration,
Frenette, M.D., Professor in the Department of Medicine at Mount
Sinai School of Medicine. "More practically, the rhythmic
oscillations of circulating stem cells suggest that harvest could be
optimized by simply timing the collection of stem cells at the peak
of release."
The vast majority of bone marrow transplantation procedures are
currently done using stem cells harvested in the peripheral blood.
The current harvesting procedure, however, may not be adequate in
some patients, particularly in those that have received prior
treatments for cancer.
"What is really amazing to us is that the brain-through the
autonomous branch of the nervous system-directly controls stem cells
in their microenvironment,
implication in today's busy world is that changes in normal
biological rhythms, for example by working night shifts or a jet lag,
could affect the number of stem cells harvested from donors,"
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StemCells subscribers may also be interested in these sites:
Children's Neurobiological Solutions
http://www.CNSfoundation.org/
Cord Blood Registry
http://www.CordBlood.com/at.cgi?a=150123
The CNS Healing Group
http://groups.yahoo.com/group/CNS_Healing
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