Slowing the aging process: It’s in your genes
An international team of scientists led by Takehiko Kobayashi at the National Institute of Genetics in Mishima, Japan, has found a new cause of aging, the instability of rDNA genes, which is controlled in yeast by the Sir2 gene. By improving the stability of rDNA, the team managed to extend the lifespan of baker’s yeast. “Although we know human rDNA genes are unstable, we don’t know if this instability affects lifespan,” says co-author Austen Ganley of Massey University in New Zealand. ”Finding this out is the next critical step, and the challenge lies in doing these experiments with human cells, which are more difficult to work with than yeast.” The work was published Aug. 29 in the journal Current Biology.
Bacteria from lean mice prevent obesity in peers
A research team led by Jeffrey Gordon at Washington University in St. Louis reported in the Sept. 6 issue of the journal Science that mice given gut bacteria from obese humans became fatter than mice given gut bacteria from lean humans. The gut bacteria samples were taken from human twins, one lean and the other obese. When the scientists gave these samples to mice that had been bred to be germ-free, they noticed that — even with identical food portions — the group receiving bacteria from lean twins kept their normal weight, whereas the ones given the obese sample quickly gained weight. In addition, when obese mice were housed with lean mice, which allowed them to exchange their microbiota through coprophagia, the obese mice slimmed down. “There’s an intricate relationship between our diet and how our gut bugs work,” says Gordon. “You have to have the right ingredients.”
Beyond CVs and impact factors: an employer’s manifesto
Sandra L. Schmid, who heads up the cell biology department at the University of Texas Southwestern Medical Center at Dallas, described Sept. 3 in Science Careers a new way her team is evaluating employment applications from assistant professors. In her essay, Schmid says she wants to use the recommendations of the San Francisco Declaration on Research Assessment and to help candidates prove their worth by methods other than journal impact factors, CVs or generic cover letters. Instead, Schmid says, she wants to give applicants the chance to present their most significant accomplishments, research visions and qualifications through brief and clear cover letters and video-conference interviews. “Our goal is to identify future colleagues who might otherwise have failed to pass through the singular artificial CV filter of high-impact journals, awards and pedigree,” Schmid writes.
Mini human ‘brains’ grown in the lab for the first time
Juergen Knoblich at the Institute of Molecular Biology in Vienna and his research team reported in August in the journal Nature that they had grown miniature organs containing parts of the cortex, hippocampus and retina. They did so using induced pluripotent stem cells and a mix of substances thought to be essential for brain development. “If you provide the right nutrients, they have amazing capacity to self-organize,” says team member Madeline Lancaster, also at the IMB. Using this method, the researchers were able to find that microcephaly is related to the lack of a protein called CDK5RAP2, which, when added to the nutrient mix, helps increase the number of neurons. Martin Coath of the Cognition Institute at Plymouth University in the U.K. says, “Any technique that gives us ‘something like a brain’ that we can modify, work on and watch as it develops has to be exciting. But just how exciting will depend on the results it produces.”
NIH scientists visualize translocation in living cells
While scientists have known for some time that translocation is an abnormal process that occurs when a segment of a chromosome breaks off and attaches correctly or incorrectly to another chromosome, this event only recently has been observed directly for the first time. “Our ability to see this fundamental process in cancer formation was possible only because of access to revolutionary imaging technology,” said the study’s senior author, Tom Misteli of the National Cancer Institute. The scientists managed to see this event by inhibiting one of the inherent DNA-repair mechanisms within cells, DNAPK-kinase, which increased the occurrence of translocations. The event apparently can take place within hours of DNA breaks and is unrelated to the moment in the cell division cycle. The results appeared Aug. 9 in the journal Science.
Cause of sunburn pain identified
A multi-institutional team of widely renowned researchers is studying the role of the TRPV4 molecule, an ion channel, in pain and tissue damage resulting from excessive ultraviolet B exposure. Writing in the Proceedings of the National Academy of Sciences, the team describes the series of events that take place once the hind paws of normal mice — which most resemble human skin — are exposed to UVB rays. TRVP becomes activated, causing the influx of calcium ions and in turn bringing endothelin, which closes the vicious circle by stimulating TRPV4 to release more calcium into the cells. This chain of events was altered when the researchers dissolved a selective inhibitor of TRPV4, a pharmaceutical compound called GSK205, in a solution of alcohol and glycerol and applied it to the hind paws of normal mice. This largely prevented the undesirable effects of sunburn by inhibiting the UVB-triggered influx of calcium ions into the cells. “The results position TRPV4 as a new target for preventing and treating sunburn,” said Martin Steinhoff, professor of dermatology and surgery at the University of California in San Francisco and a co-senior-author of the study. The other authors were Wolfgang Liedtke, associate professor of neurology and neurobiology at Duke University School of Medicine, and Elaine Fuchs, professor at the Rockefeller University and investigator with the Howard Hughes Medical Institute.
This news roundup was compiled by ASBMB Today contributor Teodora Donisan (email@example.com), a medical student at Carol Davila University in Bucharest, Romania. Send links of interest to firstname.lastname@example.org for possible inclusion in future issues.