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A number of groups are working on gene therapies for aging and age-related disease based on manipulation of telomere length. Here is some insight into what that work looks like: "Degeneration of the intervertebral disc is an age-related condition in which cells responsible for the maintenance and health of the disc deteriorate with age. Telomerase can extend the cellular lifespan and function of other musculoskeletal tissues, such as the heart, bones, and connective tissues. Therefore, extension of the cellular lifespan and matrix production of intervertebral disc cells may have the potential to delay the degeneration process. ... nucleus pulposus cells were lipofectamine transfected in vitro with a human telomerase reverse transcriptase (hTERT) expression construct ... hTERT transfection enabled a 50% extension in mean cellular lifespan and prolonged matrix production of collagen 1 and 2 for more than 282 days. ... Telomerase can extend the cellular lifespan of nucleus pulposus cells and prolong the production of extracellular matrix. Safety is still unresolved, as karyotypic instability was detected but no loss of contact inhibition, mitogen dependency, or G1-cell cycle checkpoint control was evident." That last meaning it is unclear as to whether the risk of cancer is increased by this process.
View the Article Under Discussion: http://pmid.us/17495775
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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The NYAS looks at efforts to better understand our cells - this is key to the most important potential advances in medicine foreseen for the decades ahead, such as extending the healthy human life span. "Thinking of the cell as a factory and biologists as engineers, [a] geneticist might unscrew every pipe inside the factory, one at a time for controlled experiments, of course, and determine the effect that the change has on the factory's operation, or the cell's function. A structural biologist might focus on the shape and size of one particular valve and try to determine how it contributes to the cell-factory's overall functioning. A biochemist would grind up the whole factory and then try to purify and analyze each of its various parts. ... But as scientists and engineers well know, a strictly reductionist view limits one's ability to see the big picture. A zoom-in-zoom-out process is often necessary to make significant progress in the quest for knowledge. This is the perspective of a systems biologist, who seeks to model the mechanistic details of the inner workings of a cell without losing sight of the larger experimental picture. These are the factory's engineers who create blueprints of the building, annotated in excruciating detail with its key industrial processes, and then step back to admire the plans as a whole."
View the Article Under Discussion: http://www.nyas.org/ebriefreps/main.asp?intEBriefID=637
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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The research noted by Newswise here does not strike me as the future of longevity science: "Aspirin didn't pan out. Neither did two other potential anti-aging agents. But a synthetic derivative of a pungent desert shrub is now a front-runner in ongoing animal experiments to find out if certain chemicals, known to inhibit inflammation, cancer and other destructive processes, can boost the odds of living longer. ... scientist Richard A. Miller reports early results from a mouse study his lab and two others are conducting for the National Institute on Aging. The study, now in its fourth year, will test as many as two dozen possible anti-aging agents in animals in the next five years." Discovering potentially interesting mechanisms in metabolism by testing ingestion of various chemicals is an inefficient journey along an inefficient path. We can do better than this, both in our methodology for identifying interesting mechanisms, and in the methods by which we attempt to extend healthy life span. Crude manipulations with chemicals from the environment can never hold a candle to the directed use of biotechnology to identify and repair the damage of aging. Which would you prefer scientists worked on for the next couple of decades?
View the Article Under Discussion: http://www.newswise.com/articles/view/530544/
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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Picking their test cases carefully, researchers are making progress towards a technology base for repairing nerves and brain cells: "Rats paralyzed due to loss of blood flow to the spine returned to near normal ambulatory function six weeks after receiving grafts of human spinal stem cells (hSSCs) ... We demonstrated that when damage has occurred due to a loss of blood flow to the spine's neural cells, by grafting human neural stem cells directly into the spinal cord we can achieve a progressive recovery of motor function ... Three of the nine rats injected with hSSCs returned to walking at six weeks, and three others had improved mobility in all lower extremity joints. All nine animals grafted with hSSCs achieved significantly better motor scores than those in the control group, and showed a consistent presence of transplanted cells in the spinal area. In all the rats grafted with the stem cells, the majority of transplanted human spinal stem cells survived and became mature neurons ... Other human stem cell transplants in the spinal cord have focused on repairing the myelin-forming cells. In this study, we succeeded at reconstructing the neural circuitry, which had not been done before."
View the Article Under Discussion: http://health.ucsd.edu/news/2007/5-31-stemcell-marsala.htm
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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Continued signs of progress in regenerative science from EurekAlert!: "so-called satellite cells in muscle actually include a mix of cells already committed to their muscular fate and others that behave like more versatile stem cells. The cells had widely been considered by scientists as a homogeneous population of dedicated muscle progenitors. Moreover, [researchers] showed that injection of the 'satellite stem cells' into the muscles of mice successfully replenished the animals' regenerative reservoir of cells. ... We've found that there are two types of satellite cell - 90% that are already committed to becoming muscle and another 10% with characteristics normally attributed to stem cells. It's not been shown yet, but these muscle stem cells might even have the capacity to make other tissues, such as bone and fat ... We've also shown that these satellite stem cells, when transplanted into muscle, can repopulate the regenerative cell niche. This is a very significant advance in our understanding of satellite cell biology that will require us to rethink decades of research. It also opens new avenues for therapeutic treatment of muscular diseases."
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2007-05/cp-eom052507.php
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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Why do the regenerative capacities of stem cells diminish with age, and what can be done about it? This paper looks at some of the specific mechanisms as they work to suppress young transplanted cells: "aged differentiated [stem cell] niches dominantly inhibit [certain important gene expression] in activated satellite cells, and reduce proliferation and myogenic differentiation of both embryonic [hESCs] and tissue-specific adult stem cells (ASCs). ... the ability of hESCs, and the more differentiated myogenic ASCs to contribute to tissue repair in the old will be greatly restricted due to the conserved inhibitory influence of aged differentiated niches. ... hESC-derived factors enhance the regenerative potential of both young and, importantly, aged muscle stem cells in vitro and in vivo; thus, suggesting that the regenerative outcome of stem cell-based replacement therapies will be determined by a balance between negative influences of aged tissues on transplanted cells and positive effects of embryonic cells on the endogenous regenerative capacity. Comprehensively, this work points toward novel venues for in situ restoration of tissue repair in the old and identifies critical determinants of successful cell-replacement therapies for aged degenerating organs."
View the Article Under Discussion: http://www.blackwell-synergy.com/doi/full/10.1111/j.1474-9726.2007.00286.x
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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"According to the disposable soma theory, a cost for reproduction could exist in human beings and other species and, thus, longevity could decrease when women have a higher number of children. The purpose of this article is to review the evidence in populations living or not living under natural fertility conditions, i.e. when fertility is near its biological maximum. The results indicate that in natural fertility conditions longevity does not decrease when the number of children increases but, in modern populations, mortality could slightly increase when women have more than 5 children. Complete data for these modern cohorts will tell us, one day, whether these results are still observed when the variable of interest is longevity and not only mortality." The disposable soma theory of aging, arising from evolutionary considerations, has moved through a number of interations to its present form. It is not highly regarded in comparison to other theories, largely because of this sort of evidence. The model of the body as a self-repairing machine subject to an accumulation of characteristic types of damage it cannot repair far better fits the observed facts.
View the Article Under Discussion: http://pmid.us/17532269
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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As noted at Ouroboros, there's still plenty to debate in calorie restriction science. Well-funded companies are developing therapies and human studies have been taking place for years, but discussions continue on the basic research in lesser species: "In the last decade, research into the molecular determinants of aging has progressed rapidly and much of this progress can be attributed to studies in invertebrate eukaryotic model organisms. Of these, single-celled yeast is the least complicated and most amenable to genetic and molecular manipulations. ... Activation of Sir2-family proteins in response to calorie restriction (CR) has been proposed as an evolutionarily conserved mechanism for life span extension. This idea has been called into question with the discovery that Sir2-family proteins are not required for life span extension from CR in yeast. ... Several specific cases where the Sir2 model of CR is inconsistent with experimental data are noted. These shortcomings must be considered along with evidence supporting a role for Sir2 in CR in order to fully evaluate the validity of this model." A number of other possible candidate genes and proteins have been put forward in the past year; as scientists continue to investigate, the situation will become more clear.
View the Article Under Discussion: http://ouroboros.wordpress.com/2007/05/30/skepticism-about-sir2s-role-in-yeast-cr/
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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(From EurekAlert!). Adding insult to injury: as if the destruction of your immune system over the years was not enough, cytomegalovirus also causes further direct harm to your body: " Atherosclerosis is the main cause of morbidity and mortality worldwide. ... Recently inflammation and infectious agents have been shown to play an important role in the onset of acute cardiovascular events. ... Cytomegalovirus infection can be responsible of the initial vascular lesions typical of the atherosclerotic process. The mechanism involved in the vascular lesion is of autoimmune origin: antibodies directed against particular proteins of the virus are able to bind molecules expressed on the surface of the cells that line the arterial walls ( endothelial cells) and to cause their death ( apoptosis) through a mechanism called 'molecular mimicry.' ... This new study therefore confirms that antibodies directed against Cytomegalovirus-derived proteins purified from patients with coronary artery disease induce endothelial cells damage and support the hypothesis that virus infection plays a crucial role in mediating the atherosclerotic process."
View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2007-05/plos-cea052907.php
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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Work on urinary incontinence is demonstrating that reconditioning and repairing even more subtle damage in muscle function is within the present bounds of regenerative medicine. Via Medical News Today: "Previous studies in animal models [demonstrated] that injecting stem cells into the urethral muscles increases leak point pressure, leading to the restoration of the deficient muscles. The results of these studies formed the basis for the clinical trial. [Researchers] took biopsies of skeletal muscle tissue from eight female patients and isolated and expanded the stem cells from the tissue in culture. In an outpatient setting, the patients then received injections of the muscle-derived stem cells into the area surrounding the urethra. ... Five of the eight women who participated in the study reported improvement in bladder control and quality of life with no serious short- or long-term adverse effects one year after the initial treatment. ... A multi-center study in Canada and a study in the United States are currently underway and will allow researchers to determine the optimal dose of muscle stem cells."
View the Article Under Discussion: http://www.medicalnewstoday.com/medicalnews.php?newsid=71735
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/
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