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A number of studies have shown that it is possible to lengthen theaverage life of individuals of many species, including mammals, byacting on specific genes. To date, however, this has meant alteringthe animals' genes permanently from the embryonic stage -- anapproach impracticable in humans. Researchers at the SpanishNational Cancer Research Centre (CNIO), led by its directorMaría Blasco, have demonstrated that the mouse lifespan canbe extended by the application in adult life of a single treatmentacting directly on the animal's genes. And they have done so usinggene therapy, a strategy never before employed to combat aging. Thetherapy has been found to be safe and effective in mice. The results were recently published in the journal EMBO Molecular Medicine. The CNIO team, in collaboration with Eduard Ayuso and FátimaBosch of the Centre of Animal Biotechnology and Gene Therapy at theUniversitat Autònoma de Barcelona (UAB), treated adult(one-‐year-‐old) and aged(two-‐year-‐old) mice, with the gene therapydelivering a "rejuvenating" effect in both cases,according to the authors. Mice treated at the age of one lived longer by 24% on average, andthose treated at the age of two, by 13%. The therapy, furthermore,produced an appreciable improvement in the animals' health,delaying the onset of age-‐related diseases -- likeosteoporosis and insulin resistance -- and achieving improvedreadings on aging indicators like neuromuscular coordination. The gene therapy consisted of treating the animals with aDNA-modified virus, the viral genes having been replaced bythose of the telomerase enzyme, with a key role in aging.Telomerase repairs the extreme ends or tips of chromosomes, knownas telomeres, and in doing so slows the cell's and therefore thebody's biological clock. When the animal is infected, the virusacts as a vehicle depositing the telomerase gene in the cells. This study "shows that it is possible to develop atelomerase-based anti-aging gene therapy withoutincreasing the incidence of cancer," the authors affirm."Aged organisms accumulate damage in their DNA due to telomereshortening, [this study] finds that a gene therapy based ontelomerase production can repair or delay this kind ofdamage," they add. 'Resetting' the biological clock Telomeres are the caps that protect the end of chromosomes, butthey cannot do so indefinitely: each time the cell divides thetelomeres get shorter, until they are so short that they lose allfunctionality. The cell, as a result, stops dividing and ages ordies. Telomerase gets around this by preventing telomeres fromshortening or even rebuilding them. What it does, in essence, isstop or reset the cell's biological clock. But in most cells the telomerase gene is only active before birth;the cells of an adult organism, with few exceptions, have notelomerase. The exceptions in question are adult stem cells andcancer cells, which divide limitlessly and are therefore immortal-- in fact several studies have shown that telomerase expression isthe key to the immortality of tumour cells. It is precisely this risk of promoting tumour development that hasset back the investigation of telomerase-‐basedanti-‐aging therapies. In 2007, Blasco's group demonstrated that it was feasible toprolong the lives of transgenic mice, whose genome had beenpermanently altered at the embryonic stage, by causing their cellsto express telomerase and, also, extra copies ofcancer-‐resistant genes. These animals live 40% longerthan is normal and do not develop cancer. The mice subjected to the gene therapy now under test are likewisefree of cancer. Researchers believe this is because the therapybegins when the animals are adult so do not have time to accumulatesufficient number of aberrant divisions for tumours to appear. Also important is the kind of virus employed to carry thetelomerase gene to the cells. The authors selected demonstrablysafe viruses that have been successfully used in gene therapytreatment of hemophilia and eye disease. Specifically, they arenon-‐replicating viruses derived from others that arenon-‐pathogenic in humans. This study is viewed primarily as "aproof-‐of-‐principle that telomerase genetherapy is a feasible and generally safe approach to improvehealthspan and treat disorders associated with shorttelomeres," state Virginia Boccardi (Second University ofNaples) and Utz Herbig (New Jersey MedicalSchool-‐University Hospital Cancer Centre) in acommentary published in the same journal. Although this therapy may not find application as ananti-‐aging treatment in humans, in the short term atleast, it could open up a new treatment option for ailments linkedwith the presence in tissue of abnormally short telomeres, as insome cases of human pulmonary fibrosis. More healthy years As Blasco says, "aging is not currently regarded as a disease,but researchers tend increasingly to view it as the common originof conditions like insulin resistance or cardiovascular disease,whose incidence rises with age. In treating cell aging, we couldprevent these diseases." With regard to the therapy under testing, Bosch explains:"Because the vector we use expresses the target gene(telomerase) over a long period, we were able to apply a singletreatment. This might be the only practical solution for ananti-‐aging therapy, since other strategies wouldrequire the drug to be administered over the patient's lifetime,multiplying the risk of adverse effects.". We are high quality suppliers, our products such as Ipad Protection Cover , Universal Power Adaptor For Laptops for oversee buyer. To know more, please visits 12v AC DC Adaptor.
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