Director
of Glenn Laboratories
for the Biology of Aging and Deputy Director
of the Stanford Centre on Longevity at
Stanford Univer sity, Prof. Thomas Rando
obtained his MD and PhD in cell biology
from Harvard University and completed his
residency in Neurology at The University of
California San Francisco.
Prof. Rando’s team studies a whole host
of topics related primarily to muscle biology,
in par ticular muscle stem cell biology, the
intersection between muscle stem cell biology
and aging, muscular dystrophy as well as tissue
engineering. The topic of aging cropped up
a decade ago during the study of stem cells.
They questioned, “Why is it that when people or
mice get older and older, their stem cells don’t
work as well as they do when they’re young?”
Stem cells function in two main ways. Stem
cells in muscle tissue activate in response to
injury and divide until the tissue is repaired.
Their other function is a normal, stem cell-
mediated mechanism, where stem cells in
the skin or in the gut continuously make new
cells to replace old ones. These processes
seem to deteriorate as a person ages – for
example, wounds in young chi ldren heal
much quicker than they do in older adults.
“ It’s real l y a decl i ni ng funct ion over the
whole life course”, Prof. Rando explained.
Their studies in this area involves whether
the deterioration is reversible. “If it’s genomic
– mean i ng i f i t i s re l ated to damage o r
mutat i ons i n DNA, then i t un l i kel y to be
reversible”. But if it’s anything else, then it
The Possibility of
Age
Reversal -
Prof. Thomas A. Rando
By Cherry Chow
周卓瑩
is probably reversible to some extent”. The
approach to studying age reversibility in the
per spective of stem cel l s is analogous to
genetic switching. During cell development,
dif ferentiation of the cel ls takes place to
dete rmi ne the funct i on of the ce l l and
por tions of the DNA to become inactive.
The idea of age reversibility is analogous to
turning one kind of cell to a different kind of
cell, for example a liver cell to a brain cell, by
controlling the genes expressed and masked.
“In theory, if that is partly what aging is, you
could take an old cell and make it a young
cell”. Prof. Rando’s group has already made
aged s tem cel l s funct ion l i ke a younger
cell by intervention. “At this point, we can’t
conclusively say that we’ve reversed aging
as opposed to enhancing the function of
these old cells. But we have ideas on how
to study that”. However, he explains that
no molecular definition for aging currently
exists, and is a fundamental difficulty that
needs to be addressed.
Another cha l l enge i s l imi ted t ime.
Science i s a s low proces s and s tudies
on aging i s par t icular l y dif f icult s ince
exper iments cannot commence until a
batch of test subjects (such as mice) age.
Clinical tr ials in humans would naturally
be even more challenging in length and
complexity, not to mention the ethical issues
that would accompany such experiments.
Studies on aging are, nevertheless, ongoing
and significant progress is cur rently being
made in understanding the fundamentals of
age reversal.
逆轉年齡的可行性
－
托馬斯．蘭度教授
