“Clues To Reversing Aging Of Human Muscle Discovered - Science Daily” plus 4 more |
- Clues To Reversing Aging Of Human Muscle Discovered - Science Daily
- The genetic mutation that ruins orange-coloured fish sex lives - Newstrack India
- New species of leech has roots in South Jersey - Courier-Post
- Clarksville Teacher Pleads Guilty - WTVF
- Americans want to be better informed about developments in cutting ... - News-Medical.Net
| Clues To Reversing Aging Of Human Muscle Discovered - Science Daily Posted: 30 Sep 2009 11:15 AM PDT ScienceDaily (Sep. 30, 2009) — A study led by researchers at the University of California, Berkeley, has identified critical biochemical pathways linked to the aging of human muscle. By manipulating these pathways, the researchers were able to turn back the clock on old human muscle, restoring its ability to repair and rebuild itself. The findings will be reported in the Sept. 30 issue of the journal EMBO Molecular Medicine, a peer-reviewed, scientific publication of the European Molecular Biology Organization. "Our study shows that the ability of old human muscle to be maintained and repaired by muscle stem cells can be restored to youthful vigor given the right mix of biochemical signals," said Professor Irina Conboy, a faculty member in the graduate bioengineering program that is run jointly by UC Berkeley and UC San Francisco, and head of the research team conducting the study. "This provides promising new targets for forestalling the debilitating muscle atrophy that accompanies aging, and perhaps other tissue degenerative disorders as well." Previous research in animal models led by Conboy, who is also an investigator at the Berkeley Stem Cell Center and at the California Institute for Quantitative Biosciences (QB3), revealed that the ability of adult stem cells to do their job of repairing and replacing damaged tissue is governed by the molecular signals they get from surrounding muscle tissue, and that those signals change with age in ways that preclude productive tissue repair. Those studies have also shown that the regenerative function in old stem cells can be revived given the appropriate biochemical signals. What was not clear until this new study was whether similar rules applied for humans. Unlike humans, laboratory animals are bred to have identical genes and are raised in similar environments, noted Conboy, who received a New Faculty Award from the California Institute of Regenerative Medicine (CIRM) that helped fund this research. Moreover, the typical human lifespan lasts seven to eight decades, while lab mice are reaching the end of their lives by age 2. Working in collaboration with Dr. Michael Kjaer and his research group at the Institute of Sports Medicine and Centre of Healthy Aging at the University of Copenhagen in Denmark, the UC Berkeley researchers compared samples of muscle tissue from nearly 30 healthy men who participated in an exercise physiology study. The young subjects ranged from age 21 to 24 and averaged 22.6 years of age, while the old study participants averaged 71.3 years, with a span of 68 to 74 years of age. In experiments conducted by Dr. Charlotte Suetta, a post-doctoral researcher in Kjaer's lab, muscle biopsies were taken from the quadriceps of all the subjects at the beginning of the study. The men then had the leg from which the muscle tissue was taken immobilized in a cast for two weeks to simulate muscle atrophy. After the cast was removed, the study participants exercised with weights to regain muscle mass in their newly freed legs. Additional samples of muscle tissue for each subject were taken at three days and again at four weeks after cast removal, and then sent to UC Berkeley for analysis. Morgan Carlson and Michael Conboy, researchers at UC Berkeley, found that before the legs were immobilized, the adult stem cells responsible for muscle repair and regeneration were only half as numerous in the old muscle as they were in young tissue. That difference increased even more during the exercise phase, with younger tissue having four times more regenerative cells that were actively repairing worn tissue compared with the old muscle, in which muscle stem cells remained inactive. The researchers also observed that old muscle showed signs of inflammatory response and scar formation during immobility and again four weeks after the cast was removed. "Two weeks of immobilization only mildly affected young muscle, in terms of tissue maintenance and functionality, whereas old muscle began to atrophy and manifest signs of rapid tissue deterioration," said Carlson, the study's first author and a UC Berkeley post-doctoral scholar funded in part by CIRM. "The old muscle also didn't recover as well with exercise. This emphasizes the importance of older populations staying active because the evidence is that for their muscle, long periods of disuse may irrevocably worsen the stem cells' regenerative environment." At the same time, the researchers warned that in the elderly, too rigorous an exercise program after immobility may also cause replacement of functional muscle by scarring and inflammation. "It's like a Catch-22," said Conboy. The researchers further examined the response of the human muscle to biochemical signals. They learned from previous studies that adult muscle stem cells have a receptor called Notch, which triggers growth when activated. Those stem cells also have a receptor for the protein TGF-beta that, when excessively activated, sets off a chain reaction that ultimately inhibits a cell's ability to divide. The researchers said that aging in mice is associated in part with the progressive decline of Notch and increased levels of TGF-beta, ultimately blocking the stem cells' capacity to effectively rebuild the body. This study revealed that the same pathways are at play in human muscle, but also showed for the first time that mitogen-activated protein (MAP) kinase was an important positive regulator of Notch activity essential for human muscle repair, and that it was rendered inactive in old tissue. MAP kinase (MAPK) is familiar to developmental biologists since it is an important enzyme for organ formation in such diverse species as nematodes, fruit flies and mice. For old human muscle, MAPK levels are low, so the Notch pathway is not activated and the stem cells no longer perform their muscle regeneration jobs properly, the researchers said. When levels of MAPK were experimentally inhibited, young human muscle was no longer able to regenerate. The reverse was true when the researchers cultured old human muscle in a solution where activation of MAPK had been forced. In that case, the regenerative ability of the old muscle was significantly enhanced. "The fact that this MAPK pathway has been conserved throughout evolution, from worms to flies to humans, shows that it is important," said Conboy. "Now we know that it plays a key role in regulation and aging of human tissue regeneration. In practical terms, we now know that to enhance regeneration of old human muscle and restore tissue health, we can either target the MAPK or the Notch pathways. The ultimate goal, of course, is to move this research toward clinical trials." Other co-authors of the EMBO Molecular Medicine paper include Abigail Mackey at the University of Copenhagen in Denmark, and Per Aagaard at the University of Southern Denmark. The National Institutes of Health, the California Institute of Regenerative Medicine, the Danish Medical Research Council and the Glenn Foundation for Medical Research helped support this research. Journal reference:
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| The genetic mutation that ruins orange-coloured fish sex lives - Newstrack India Posted: 28 Sep 2009 10:23 PM PDT
Washington, Sept 29 (ANI): Researchers from University of Konstanz, Germany and the University of Tokyo have found a genetic mutation that gives medaka fish its grey colour, rendering them less attractive to the colourful members of the opposite sex. The Japanese Killifish is commonly found in Southeast Asia in wide range of colours like brown, orange and grey.
The research team led by Shoji Fukamachi studied the effects of alterations in a colour-determining gene on mating preferences of the fish. The greys, however, need not be completely despondent at these findings, as the study also showed that they were preferentially selective for each other. "We observed that the grey medaka were often rejected in favour of their brown or orange rivals," said Fukamachi. "This is the first demonstration of a single gene that can change both secondary sexual characteristics and mating preferences," the expert added. Orange colour in medaka is determined by the presence of pigmented structures known as xanthophores, and these are reduced in the grey fish carrying the mutant gene. By over-expressing this same gene, the researchers created super attractive bright orange medaka that induced hyperactivity in similarly engineered members of the opposite sex while other potential mates were ignored almost completely. "Thus, the present finding of the xanthophore-dependent mate choice enables many ingenious experiments to be designed in this and other fish species," said Fukamachi. "This discovery should further facilitate molecular dissection/manipulation of visual-based mate choice," Fukamachi added. The study appears in open access journal BMC Biology. (ANI) |
| New species of leech has roots in South Jersey - Courier-Post Posted: 30 Sep 2009 04:56 AM PDT CAMDEN — An inky black, worm-eating leech discovered in a Salem County yard has been declared a new species, according to Rutgers-Camden researchers. Haemopis ottorum was named after the Ott family of Alloway, which first brought the creature to Daniel Shain, one of the nation's few leech experts and an associate professor of biology at Rutgers-Camden. Their find is documented in a recent edition of the journal Molecular Phylogenetics and Evolution. The majority of the world's terrestrial leeches are found in tropical areas, but Haemopis ottorum lives in the swampy, wooded areas and cedar bogs of South Jersey. It is one of only three known North American terrestrial leeches. And compared with most of the world's leeches, it's a monster. The first specimen was more than a foot long and grew to about 17 inches. It has a sucker on one end. On the other end, its pointy head has a mouth that stretches wide to swallow its prey whole. Bill Ott found that first specimen while mowing the lawn on a hot July day in 2003. His wife, Carol, kept the creature alive for months in an aquarium while searching for more information about it online but she couldn't find anything. She did find Shain, and hand-delivered it to his Pennsville home. "I just was so curious and I knew it was something so different and so cool," said Ott. "We're very inquisitive people anyway. We love nature and anything like that." Certain they had a new species on their hands, Shain and his students dubbed the leech "Piwi" after a stem cell gene they were studying. Research stalled, however, when the hermaphroditic creature did not reproduce in the lab. More specimens were needed, but it turned out the leech was hard to find. Beth Wirchansky, then a graduate student, took up the project. Working with other students, she spent three years hunting for more "Piwi" leeches around South Jersey, studying topographical maps to find possible sites. "Leeches are really fascinating creatures when you start to look at them," said Wirchansky, co-author of the paper with Shain and a May graduate with a master's in biology. "They're extremely complex. They're very diverse and have very interesting life strategies. There's not a lot known about them." |
| Clarksville Teacher Pleads Guilty - WTVF Posted: 22 Sep 2009 07:21 AM PDT CLARKSVILLE, Tenn. - A former Clarksville teacher pleaded guilty to misdemeanor charges of showing harmful material to a minor. Jessica Percifull was a biology teacher at Northeast High School last fall when she allegedly sent a nude picture to a 17-year-old student. Percifull was originally charged with sexual exploitation of a minor, but instead she pleaded guilty to the misdemeanor charges. The former teacher was sentenced to nearly two years diversion and probation. She was fired from her job in February. |
| Americans want to be better informed about developments in cutting ... - News-Medical.Net Posted: 01 Oct 2009 04:26 AM PDT Landmark poll shows that 9 in 10 Americans want to know more about the development of emerging technologies Nanotechnology and synthetic biology continue to develop as two of the most exciting areas of scientific discovery, but research has shown that the public is almost completely unaware of the science and its applications. A groundbreaking poll of 1,001 American adults conducted by Peter D. Hart Research Associates and the Project on Emerging Nanotechnologies (PEN) found that 90 percent of Americans think the public should be better informed about the development of cutting-edge technologies. "Historically, government and industry have done a poor job of informing and engaging the public about scientific developments that could have transformative impacts on society," said David Rejeski, director of PEN. "The poll showed that better communication is needed and could be beneficial in securing the promise of our investments in science." The poll, which was conducted by the same firm that produces the well-known NBC News/Wall Street Journal polls, revealed that the proportion of adults who say they have heard a lot or some about synthetic biology more than doubled in the past year (from 9 percent to 22 percent). Awareness of nanotechnology (30 percent have heard a lot or some) increased slightly since last year, putting it back at the same level measured in 2006. A report which summarizes the findings of the poll can be found at http://www.nanotechproject.org/news/archive/hart4/. "Public awareness of nanotechnology has barely moved in over four years of our project's polling, despite billions of dollars of investment in research and a growing number of nano-enabled products in the marketplace," said Andrew Maynard, chief science advisor for PEN. "Clearly, the message about this new and important technology is not reaching the public." The survey showed that the area of application is a decisive factor in shaping public attitudes towards synthetic biology. Over half the respondents supported research in synthetic biology aimed at the development of more efficient biofuels even after being informed of the potential risks and benefits of this application. However, poll respondents harbored concerns about potential risks associated with the development of synthetic biology. Two-thirds of the participants supported regulation of this emerging technology. "Regardless of their awareness of synthetic biology, or where they come down on the risk-benefit tradeoff, a strong majority of adults think this research should be regulated by the federal government," said Geoff Garin, president of Peter D. Hart Research Associates. About Nanotechnology: Nanotechnology is the ability to measure, see, manipulate and manufacture things usually between 1 and 100 nanometers. A nanometer is one billionth of a meter; a human hair is roughly 100,000 nanometers wide. In 2007, the global market for goods incorporating nanotechnology totaled $147 billion. Lux Research projects that figure will grow to $3.1 trillion by 2015. About Synthetic Biology: Synthetic biology is the use of advanced science and engineering to make or re-design living organisms, such as bacteria, so that they can carry out specific functions. Synthetic biology involves making new genetic code, also known as DNA, that does not already exist in nature. SOURCE The Project on Emerging Nanotechnologies |
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