In the August 2002 issue of Reason science writer Ron Bailey has written an excellent article surveying the prospects for various anti-aging techniques to slow and even reverse aging. He covers everything from the efficacy of antioxidants to the future prospects for gene therapy, artificial chromosomes, organ replacements, cell therapy, and nanotechnology.
I'm including a couple of excerpts to whet your appetites for the full article. In the first excerpt the discussion is about cell therapy to reseed cell populations. Note that there are adult stem cell reservoirs throughout the body used for everything from new memory formation, tissue repair, to immune cell generation. The stem cells in all those reservoirs age. Replacement of those aged cells with rejuvenated cells would partially restore youthfulness of the body:
Stem cells have been found in adult tissues, in umbilical cord blood from newborns, and in embryos. All have shown some promise. William Haseltine, the CEO of Human Genome Sciences, recently predicted in The Washington Post that it will one day be possible to "reseed the body with our own cells that are made more potent and younger, so we can repopulate the body." But stem cell transplants are at least 10 years away -- or even longer, if Leon Kass and his allies succeed in banning therapeutic cloning. Since the chorus calling for a ban includes President Bush, the prospects for research in this area are not as bright as they ought to be.
Aubrey de Grey's suggestion here is to use some form of gene therapy to move the mitochondrial DNA (mtDNA) genes into the nucleus where they are no longer close to the pathways that produce ATP energy molecules. Those pathways are responsible for a large fraction of the total number of free radicals generated in the body (by throwing off superoxide) and are a major cause of aging.
The Cambridge gerontologist Aubrey de Grey wants to genetically engineer mitochondrial genes into the nuclei of cells, where they would be better protected from the ravages of free radicals. He believes that once those genes are better protected they will not be so quickly mutated into the free radical death spiral. Once the vicious circle of mitochondrial mutations producing ever more free radicals is broken, longer life should result, he argues.
Aubrey's suggestion can be combined with the idea of reseeding adult stem cell reservoirs. Some day it will be possible to take some tired old adult stem cells from the body, do gene therapy to repair and rejuvenate them and also perform the gene therapy that also moves the mtDNA genes into the nucleus. Then reintroduce the rejuvenated adult stem into the body, The advantage of this approach is that as the adult stem cells gradually reproduced and differentiated into other cell types various portions of the body would gradually become the improved younger and more slowing aging cell types. Other genetic improvements besides the mtDNA-to-nucleus improvement could be introduced using this approach.
One of the lessons here is that while it will certainly become possible to genetically engineer progeny to be more resistant to aging those of us already alive with our own flawed genomes are not stuck with the hand that nature initially dealt us. Most of the genetic improvements that will be doable to progeny will also be doable to us if we can only live long enough to be around when the techniques become available. Gene therapy to make youthful replacement adult stem cells is not the only way this will be done. Another way would be thru organ replacement. It will some day be possible to take a cell sample from a person, apply rejuvenating and repair gene therapies and gene therapies that make the cells more resistant to aging. Then grow a new liver, stomach, or other organ from the rejuvenated cells and surgically put in the newer and longer lasting organ.
If you want to read even more then a great place to start is Aubrey de Grey's book The Mitochondrial Free Radical Theory of Aging.
P.S. I'm not going to post any more FuturePundit articles today because your time would be better spent reading Ron's full article if you haven't already read it. ;)
|Share |||Randall Parker, 2002 September 30 11:22 AM Aging Reversal|