LONGEVITY MEME NEWSLETTER
November 24 2008
The Longevity Meme Newsletter is a weekly e-mail containing news, opinions and happenings for people interested in healthy life extension: making use of diet, lifestyle choices, technology and proven medical advances to live healthy, longer lives.
- Meetings Scientific and Speculative
- Another Win For Recellularization
- Latest Healthy Life Extension Headlines
MEETINGS SPECULATIVE AND SCIENTIFIC
Bloggers from the transhumanist and aging research communities were kind enough to report on conferences they attended recently. Firstly, the Convergence 08 unconference:
"Convergence08 examines the world-changing possibilities of nanotech and the life-changing promises of biotech. ... A number of well known names from the healthy life extension community were there to present and exchange views."
Secondly, the annual meeting of the Larry L. Hillblom Foundation, one of a number of non-profit organizations to fund research into the biochemistry of aging:
"Bob Hughes, Pankaj Kapahi, Simon Melov and Gordon Lithgow (Buck Institute) gave a group talk under the umbrella topic 'Chemical biology of aging' (we heard a bit about this at last year's meeting). Bob introduced a screen for small molecules that extend lifespan in simple model system; the goal is to screen 100,000 compounds, identify drugs that increase longevity in both yeast and worms, and then test these molecules in mice."
ANOTHER WIN FOR RECELLULARIZATION
The technology of recellularization has been attracting more mainstream press attention of late - as well it should, given its potential for bringing forward the first wave of replacement organs grown to order and transplanted to replace damaged tissue:
"An article on a successful transplant of a recellularized organ is doing the rounds in the mainstream press: First a section of trachea was taken from a donor and stripped of cells that could cause an immune reaction, leaving a grey trunk of connective tissue. Stem cells were then taken from Ms Castillo's bone marrow and grown in Professor Birchall's laboratory. Stem cells can develop into different kinds of tissue, given the right chemical instructions, enabling researchers to cultivate cartilage and epithelial cells to cover the 7cm graft. It was then "seeded" with the new cells using a process developed in Milan. Finally the trachea, covered in cartilage and lined with epithelial cells, was cut to shape and fitted. Professor Macchiarini said: 'The probability that this lady will have rejection is almost zero. She is enjoying a normal life, which for us clinicians is the most beautiful gift.'"
Based on other recent research in this field, recellularized heart transplants will soon follow:
The highlights and headlines from the past week follow below.
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LATEST HEALTHY LIFE EXTENSION HEADLINES
To view commentary on the latest news headlines complete with links and references, please visit the daily news section of the Longevity Meme: http://www.longevitymeme.org/news/
Cryonics as Emergency Medicine (November 21 2008)
From Depressed Metabolism: "One of the most neglected aspects of cryonics is that its procedures, and the research to support them, can have important practical applications in mainstream fields such as organ preservation and emergency medicine. Contrary to popular opinion, cryonics does not just involve an optimistic extrapolation of existing science but can set the standard for these disciplines. As a matter of fact, that is exactly what cryonics, and cryonics associated research, has been doing over the last 25 years. ... it is encouraging to observe that some of the procedures that are routine in cryonics stabilization protocol are starting to catch on in mainstream emergency medicine practice as well. For example, contemporary cryonics stabilization protocol has been strongly shaped by the idea that the best strategy to limit brain injury after cardiac arrest is to combine a number of different interventions: cardiopulmonary support, induction of hypothermia, and administration of circulation-supporting and neuroprotective medications. It is therefore very encouraging to learn that the Wake County EMS group in North Carolina has achieved impressive results in treating out-of-hospital cardiac arrest victims using a protocol that closely follows elements of current cryonics stabilization protocol."
Building New Pancreatic Cells (November 21 2008)
Regenerative medicine advances, step by step: "researchers have developed an unlimited number of pure insulin-producing cells from mouse embryonic stem cells (ESCs). ... These pure insulin-producing cells, which according to electron microscopy studies, have the same sub-cellular structures as the insulin-producing cells naturally found in the pancreas, were highly effective in treating diabetes in the mouse model. The transplants of pure insulin-producing cells reduced the blood glucose levels of diabetic mice with high blood glucose levels. ... None of the diabetic mice involved in the transplant experiments developed teratoma, which are a type of tumour often associated with ESCs and which could complicate their use in human therapeutic treatment. Furthermore, the pure insulin-producing cells managed to retain their insulin-production and glucose-sensing capacity over time. ... Besides providing a tool to facilitate basic research in test tubes and animals, these insulin-producing cells may be also used to replace the isolated native pancreatic cells that are hard to obtain in a large amount, for pharmacological tests."
Calorie Restriction Versus Mitochondrial Damage (November 20 2008)
From Ouroboros: "In addition the 23 chromosome nuclear genome most of us are familiar with, mitochondria contain their own, distinct genome. Each mitochondrion contains several copies of this genome, and most cell types contain hundreds of mitochondria per cell. ... [Researchers] measured the number of abasic sites [or AP sites] in the mitochondrial genome of young and aged rat brain. AP sites are positions along the DNA backbone where no adenine, guanine, cytosine, or thymine is attached; they are among the most frequent damages to DNA. The authors showed that in normally feeding animals, the number of AP sites increases with age - but calorie restricted (CR) mice did not show such an increase." Since accumulating mitochondrial DNA damage is a root cause of much age-related biochemical damage throughout the body, and since calorie restriction extends healthy longevity in laboratory animals, it makes sense that CR reduces the rate at which this damage accumulates.
Towards Accurate Biomarkers of Aging (November 20 2008)
From EurekAlert!: researchers "have identified for the first time biomarkers of aging which are highly predictive of both chronological and physiological age. Biomarkers are biochemical features that can be used to measure the progress of disease or the effects of treatment. The research involves nematode worms, microarrays which measure changes in gene expression, and complex computer algorithms. This is the first step toward identifying similar biomarkers in humans which would provide a means of scientifically validating anti-aging therapies. ... This is the first evidence that physiological age can be predicted non-subjectively. This is a first step; our results were not perfect, but we were able to predict the ages of the animals 70% of the time, which is far better than anything that has been done before. ... Research into the biology of aging in humans has been hampered by the lack of irrefutable biomarkers that correlate with the aging process. I am confident that at some point there will be a non-subjective method of determining how old someone is with a high level of confidence."
Inflammation and Alzheimer's (November 19 2008)
A prodrome is an early set of non-specific symptoms that herald a particular disease. Here, researchers point to chronic inflammation as a prodrome of Alzheimer's (AD): "Recently, the term 'inflammaging' was coined [to] characterize a widely accepted paradigm that ageing is accompanied by a low-grade chronic up-regulation of certain pro-inflammatory responses. Inflammaging differs significantly the from [traditional] acute inflammation in that it is characterized by a relative decline in adaptive immunity ... While the over-active innate immunity characteristic of inflammaging may remain subclinical in many elderly individuals, a portion of individuals (postulated to have a "high responder inflammatory genotype") may shift from a state of "normal" or "subclinical" inflammaging to one or more of a number of age-associated diseases. ... Although conditions of enhanced innate immune response with overproduction of pro-inflammatory proteins are associated with both healthy aging and AD, it is suggested that those who age 'well' demonstrate anti-inflammaging mechanisms and biomarkers that likely counteract the adverse immunity of inflammaging. Thus, opposing the features of inflammaging may prevent or treat the symptoms of AD."
Regeneration Via Embryonic Stem Cells (November 19 2008)
From Reuters: "Stem cells from tiny embryos can be used to restore lost hearing and vision in animals, researchers said Tuesday in what they believe is a first step toward helping people. One team repaired hearing in guinea pigs using human bone marrow stem cells, while another grew functioning eyes in tadpoles using frog cells. ... They grew the stem cells into neuron-like cells in lab dishes and then transplanted them into the inner ears of the guinea pigs. Three months later, the animals appeared to have some hearing ... the goal was to regrow the tiny hair cells that are essential for mammals to hear, although she is not sure yet how the stem cells made this happen. They would eventually like to try something similar in humans." These are early stage proof-of-concept demonstrations. It is an illustration of progress that they do not stand out as exceptional amidst advances in the many other lines of regenerative research presently taking place.
Personal Philosophies of Longevity (November 18 2008)
I think this post over at Pimm might be an example of the entrepreneurial mind ("why would anyone not want this product that I believe in and toil to build?") being confused by the scientific mind ("look at what can be achieved if we go about it the right way"): "How do you interpret the following situation: we have a life extension technologist whose all endeavors is about pushing this issue to its very limits and making things possible but on the other hand this very life extensionist himself is not driven by actually living as long as he can. It seems that SENS theorist Aubrey de Grey [is] taking roughly the above position [by saying] 'I'm actually not mainly driven by a desire to live a long time. I accept that when I'm even a hundred years old, let alone older, I may have less enthusiasm for life than I have today. Therefore, what drives me is to put myself (with luck) and others (lots and lots of others) in a position to make that choice, rather than having the choice progressively ripped away from me or them by declining health. Whether the choice to live longer is actually made is not.'" I've long said that the purpose of longevity science, like most other scientific progress, is to provide new freedoms and choices - the choice to live longer in good health, and the freedom to do so.
More on the Biochemical Value of Exercise (November 18 2008)
Exercise is good for you: "A new study confirms that exercise can reverse the age-related decline in the production of neural stem cells in the hippocampus of the mouse brain, and suggests that this happens because exercise restores a brain chemical which promotes the production and maturation of new stem cells. ... One hypothesis the researchers investigated is that the age-related decline in neurogenesis is tied to a rise in corticosterone in middle age. Elevation of corticosterone has been associated with a drop in the production of new stem cells in the hippocampus. The second hypothesis is that nerve growth factors -- which encourage new neural cell growth but which decrease with age -- account for the drop in neurogenesis. ... production of neural stem cells improved by approximately 200% compared to the middle-aged mice that did not exercise. In addition, the survival of new nerve cells increased by 170% and growth by 190% compared to the sedentary middle-aged mice. ... Based on these results, it appears that nerve growth factor has more to do with these findings than the corticosterone."
Tau Tangles Linked With Failing Memory (November 17 2008)
From ScienceDaily: "Scientists examined the brains of five deceased people considered super aged because of their high performance on memory tests when they were more than 80 years old and compared them to the brains of elderly, non-demented individuals. Researchers found the super aged brains had many fewer fiber-like tangles than the brains of those who had aged normally. The tangles consist of a protein called tau that accumulates inside brain cells and is thought to eventually kill the cells. Tangles are found in moderate numbers in the brains of elderly and increase substantially in the brains of Alzheimer's disease patients. ... It was always assumed that the accumulation of these tangles is a progressive phenomenon through the aging process. But we are seeing that some individuals are immune to tangle formation and that the presence of these tangles seems to influence cognitive performance." Another type of intracellular aggregate to add to the list for removal by bioremediation.
More on Telomerase and Mouse Longevity (November 17 2008)
Ouroboros weighs in on a recent demonstration of enhanced longevity via telomerase: "Telomerase is tightly repressed in most somatic cells, and for a very good reason: What do you call a cell with an unlimited division potential that's not a stem cell or germ cell? Usually 'cancer.' ... But what if cancer couldn't form for other reasons? In such a case, we could test the hypothesis that increased regenerative capacity [induced via telomerase] confers increased lifespan. ... why is the effect only on median lifespan? ...Mouse cells have really long telomeres, and telomerase expression is widespread in mouse tissues (though not usually at high enough levels to prevent some telomere shortening at every cell division) ... it makes me wonder what's going on. Could telomerase be doing something else - i.e., something other than lengthening telomeres - that is particularly important in determining median lifespan?" I'd wager on protection of mitochondria, a recently discovered secondary (but possibly more important) action of telomerase.