{"70083":{"#nid":"70083","#data":{"type":"news","title":"Scientists Turn Back the Clock on Adult Stem Cells Aging","body":[{"value":"\u003Cp\u003EResearchers have shown they can reverse the aging process for\nhuman adult stem cells, which are responsible for helping old or damaged\ntissues regenerate. The findings could lead to medical treatments that may\nrepair a host of ailments that occur because of tissue damage as people age. A\nresearch group led by the Buck Institute for Research on Aging and the Georgia\nInstitute of Technology conducted the study in cell culture, which appears in\nthe September 1, 2011 edition of the journal Cell Cycle.\u003C\/p\u003E\n\n\u003Cp\u003EThe\nregenerative power of tissues and organs declines as we age. The modern day\nstem cell hypothesis of aging suggests that living organisms are as old as are its\ntissue specific or adult stem cells. Therefore, an understanding of the\nmolecules and processes that enable human adult stem cells to initiate\nself-renewal and to divide, proliferate and then differentiate in order to\nrejuvenate damaged tissue might be the key to regenerative medicine and an eventual\ncure for many age-related diseases. A research group\nled by the Buck Institute for Research on Aging in collaboration with the Georgia Institute of Technology, conducted the study that\npinpoints what is going wrong with the biological clock underlying the limited division of\nhuman adult stem cells as they age.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cWe\ndemonstrated that we were able to reverse the process of aging for human adult\nstem cells by intervening with the activity of non-protein coding RNAs originated from\ngenomic regions once dismissed as non-functional\u0026nbsp; \u2018genomic junk\u2019,\u201d said Victoria Lunyak, associate professor at the Buck Institute\nfor Research on Aging.\u003C\/p\u003E\n\n\u003Cp\u003EAdult\nstem cells are important because they help keep human tissues healthy by\nreplacing cells that have gotten old or damaged. They\u2019re also multipotent,\nwhich means that an adult stem cell can grow and replace any number of body\ncells in the tissue or organ they belong to. However, just as the cells in\nthe liver, or any other\norgan, can get damaged over time, adult stem cells undergo age-related damage. And when this happens, the body\ncan\u2019t replace damaged tissue as well as it once could, leading to a host of diseases\nand conditions. But if scientists can find a way to keep these adult stem cells\nyoung, they could possibly use these cells to repair damaged heart tissue after\na heart attack; heal wounds; correct metabolic syndromes; produce insulin for\npatients with type 1 diabetes; cure arthritis and osteoporosis and regenerate\nbone.\u003C\/p\u003E\n\n\u003Cp\u003EThe\nteam began by hypothesizing that DNA damage in the genome of adult stem cells would\nlook very different from age-related damage occurring in regular body cells. They thought\nso because body cells are known to experience a shortening of the caps found at\nthe ends of chromosomes, known as telomeres. But adult stem cells are known to\nmaintain their telomeres. Much of the damage in aging is widely thought to be a\nresult of losing telomeres. So there must be different mechanisms\nat play that are\nkey to explaining how aging occurs in these adult stem cells, they thought.\u003C\/p\u003E\n\n\u003Cp\u003EResearchers\nused adult stem cells from humans and combined experimental techniques with\ncomputational approaches to study the changes in the genome associated with\naging.\u0026nbsp; They compared freshly isolated human adult stem cells from young individuals, which can\nself-renew, to cells\nfrom the same individuals that were subjected to prolonged passaging in\nculture. This accelerated model of adult stem cell aging exhausts the regenerative\ncapacity of the adult stem cells. Researchers looked at the changes in genomic sites that accumulate\nDNA damage in both groups.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cWe\nfound the majority of DNA damage and associated chromatin changes that occurred\nwith adult stem cell aging were due to parts of the genome known as retrotransposons,\u201d\nsaid King Jordan, associate professor in the School of Biology at Georgia Tech.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cRetroransposons\nwere previously thought to be non-functional and were even labeled as \u2018junk DNA\u2019, but accumulating evidence\nindicates these elements play an important role in genome regulation,\u201d he\nadded.\u003C\/p\u003E\n\n\u003Cp\u003EWhile\nthe young adult stem cells were able to suppress transcriptional activity of\nthese genomic elements and deal with the damage to the DNA, older adult stem cells were\nnot able to scavenge this transcription. New discovery suggests that this event is deleterious\nfor the regenerative\nability of stem cells and triggers a process known as cellular senescence.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cBy\nsuppressing the accumulation of toxic transcripts from retrotransposons, we\nwere able to reverse the process of human adult stem cell aging in culture,\u201d\nsaid Lunyak.\u003C\/p\u003E\n\n\u003Cp\u003E\u201cFurthermore,\nby rewinding the cellular clock in this way, we were not only able to\nrejuvenate \u2019aged\u2019 human stem cells, but to our surprise we were able to reset\nthem to an earlier developmental stage, by up-regulating the \u201cpluripotency factors\u201d \u2013 the proteins\nthat are critically involved in the self-renewal of undifferentiated embryonic\nstem cells.\u201d she said.\u003C\/p\u003E\n\n\u003Cp\u003ENext\nthe team plans to use further analysis to validate the extent to which the\nrejuvenated stem cells may be suitable for clinical tissue regenerative\napplications.\u003C\/p\u003E\n\n\u003Cp\u003E\u003Cem\u003EThe\nstudy was conducted by a team with members from the Buck Institute for Research\non Aging, the Georgia Institute of Technology, the University of California,\nSan Diego, Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer\nCenter, International Computer Science Institute, Applied Biosystems and\nTel-Aviv University.\u003C\/em\u003E\u003C\/p\u003E\n\n\u003Cp\u003E\u003Cstrong\u003ECitation:\u003C\/strong\u003E\u003Cbr \/\u003E\n\u003Ca href=\u0022http:\/\/www.landesbioscience.com\/journals\/cc\/article\/17543\/\u0022\u003EInhibition\nof activated pericentromeric SINE\/Alu repeat transcription in senescent human\u003Cbr \/\u003E\nadult stem cells reinstates self-renewal.\u003C\/a\u003E\u0026nbsp; Cell Cycle, Volume 10, Issue 17, September 1, 2011\u003C\/p\u003E\u003Cp\u003EWritten by\nDavid Terraso, Georgia Tech\/Kris Rebillot, Buck Institute\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EResearchers have shown they can reverse the aging process for human\nadult stem cells, which are responsible for helping old or damaged tissues regenerate.\nThe findings could lead to medical treatments that may repair a host of\nailments that occur because of tissue damage as people age.\u0026nbsp;\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Reversing the aging process could lead to medical treatments  for many chronic conditions ."}],"uid":"27310","created_gmt":"2011-09-20 08:39:42","changed_gmt":"2016-10-08 03:10:09","author":"David Terraso","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2011-09-20T00:00:00-04:00","iso_date":"2011-09-20T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"groups":[{"id":"1214","name":"News Room"}],"categories":[{"id":"146","name":"Life Sciences and Biology"}],"keywords":[{"id":"176","name":"aging"},{"id":"14349","name":"Buck Institute for Research on Aging"},{"id":"4896","name":"College of Sciences"},{"id":"5268","name":"King Jordan"},{"id":"167130","name":"Stem Cells"},{"id":"14350","name":"Victoria Lunyak"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJason Maderer, 404-385-2966\u003C\/p\u003E","format":"limited_html"}],"email":["jason.maderer@comm.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}