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From Jerry Zhu's post: Scientists shed new light on aging process - Yahoo! News http://news.yahoo.com/s/nm/20050630/hl_nm/hongkong_ageing_dc_4 An Excerpt... In 2003, a team of scientists in the United States found that progeria was caused by mutation in a protein called Lamin A, which lines the nucleus in human cells. A team at the University of Hong Kong, led by Zhou Zhongjun, took the research a step further in 2004 and found that mutated Lamin A actually disrupted the repair process in cells, thus resulting in accelerated aging. The study was published in the July issue of the Nature Medicine journal. Zhou said the team came by their findings after comparing skin cells taken from two progeria sufferers, normal humans, progeria mice and normal mice. While damaged DNA was quickly repaired in the healthy human and mice cell samples, the samples taken from the progeria humans and mice had difficulty repairing damaged DNA. "Mutation in this protein (Lamin A) can cause defects in repair and thus lead to progeria," Zhou, a research assistant professor with the biochemistry department at the University of Hong Kong, said in an interview. "DNA damage is not effectively repaired in cells with defective Lamin A but very efficiently repaired in normal cells." The study highlights the importance of Lamin A to the repair process, and any mutation to Lamin A that disrupts repair will bring about aging, Zhou said. Jerry, Thanks for posting the link to that article. Aging
(senescence) was one of Robert Rosen's areas of interest, after he was
asked to participate in a special research commission during the Carter
presidency (I have a picture of him with Roslynn Carter). I find this
study very interesting. But, like you, I don't think they have "discovered" what
causes aging. Instead, I think they have discovered one of the peculiarities in
a disease process that mimics aging. Once again, the entailments are what need
to be looked into, not merely the symptoms. They apparently think
similar symptoms (normal aging vs. progeria) are automatically due to similar
underlying causes. But that's like saying that cocaine actually IS
happiness.
In order to say that the mutation of the gene which creates "Lamin
A" is involved in normal aging, I would want to see what sorts of environmental
factors can impact the gene and cause it to mutate. I find it hard to believe
that the gene will spontaneously mutate in exactly that way, in all body cells,
over time... and is somehow induced to mutate early in progeria
sufferers.
On the other hand, this study does demonstrate that the
inter-cellular immune system (part of the organism repair function) can be
extremely important to overall health. Most people, when the immune system
is mentioned, think of the general, bodily system, not the inter-cellular
component.
I've been fascinated by this aspect of immune system function ever
since high school, when we learned about mitochondrial DNA. It's only been
recently that I've been able to find much on the internet in the way of new
studies into how the mitochondria are able to co-exist with the inter-cellular
immune system, when they are basically a foreign protein. We have to logically
assume that the body's "self" proteins are nuclear proteins, because there are
large numbers of mitochondria in most body cells and they are not always the
same, genetically. Many baffling afflictions may be attributable to auto-immune
attack on mitochondria; I've seen both fibromyalgia and chronic
fatigue syndrome mentioned in connection with this. I wonder if other
auto-immune syndromes may also be triggered by the mitochondria being "outed" to
the extra-cellular component of the immune system, somehow.
There's also the phenomenon of "programmed cell death" which is a
normal, necessary feature of many aspects of living physiology. For
example, in a developing embryo the hands develop from a flipper-like appendage,
with the fingers initially all attached to each other with "webbing" in between.
The tissue then dies and is resorbed in the appropriate areas to create
separate, articulating fingers. (Occasionally babies are born with this tissue
still present and it freaks people out.) Women experience programmed cell death
of the lining of the uterus every month, if pregnancy doesn't occur. This is
what causes menstruation. (Such a joy!) My father speculated that programmed
cell death may be involved in aging, in some aspect. He thought we should study
the phenomenon to learn what triggers it and how it is carried out. Now THAT
would be a useful cancer tumor treatment!
Well, it's getting late. When the brain gets tired, the brainwaves
begin to ramble....
Judith
----- Original Message ----- From: Jerry Zhu To: *** Sent: Saturday, July 02, 2005 11:56 AM Subject: [ROSEN] Material reductionists Today's biologists are material reductionists. Everything in life is reducible to substance i.e. the ability of cell's self repare that controls aging process is reducible to segment of protein. The idea of cell self repare is not a primitive term and cannot be used as basic statements to derive conclusions. |