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In April 2007 Prof Nayernia and colleagues, from the Northeast England
Stem Cell Institute (NESCI), isolated human "mesenchymal" stem cells
from bone marrow they had extracted from male volunteers and stimulated
them using a type of vitamin A to develop into male reproductive cells
or "germ cells".
The presence of genetic markers showed that the germ cells also
contained "spermatagonial stem cells", an early stage version of male
sperm cells.
In an earlier study Prof Nayernia's scientists were able to make
spermatagonial cells from the bone marrow of mice, insert them in the
testes of live mice, watch them divide (go through meiosis) and develop
into mature sperm cells.
To those familiar with TCM (Traditional Chinese Medicine) this is interesting but not particularly surprising.
TCM has always taught that the Kidneys (Shen Zang) are closely
related to bone, brain and reproductive functions. They claim that the
functions of the Kidney are:
1. to store the essence (Jing) and that the essence
a. Rules birth, growth, development, and reproduction.
b. Rules the bones.
2. Is the foundation of Yin Yang (the balance of opposites, the interaction of which produces change and gives form)
3. Rules water
4. Rules reception of QI (vital energy)
5. Opens into the ears; Manifests in the hair.
In TCM the Kidney Yin aspect of Jing is the material basis for
tissues such as the Marrow, Bones, Brain, Blood and Sperm. While the
Yang aspect of Jing is responsible for warming, moving and activating
the Jing related tissues. Hence it is not surprising to find Jing in
present in the bones.
That the human cells failed to reach maturity indicates that
correct Kidney Yang and probably the Liver Qi was not present. In TCM
it is recognized that the Liver acupuncture channel has a connection to
and control over the testes. This could explain the fact that the early
stage mice sperm cells when implanted in the testes continues to
develop.
The researchers working on sperm cell production hope their work
will one day lead to new treatments to help infertile men, for example
after going through chemotherapy. However some scientists, while
welcoming the breakthrough say that there is still a long way to go
before sperm cells produced in this way can be shown to fertilize a
human egg.
Others are saying that a raft of difficult ethical questions have
to be addressed before applications to human fertility can be
considered, for example should this open the door to female only sperm
cells, where a woman could make a baby with another woman?
And there are also questions about the long term genetic effects
that creating sperm in this way might have on the health and
development of embryos and the children and adults they eventually
become.
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