UNSW researchers unveil “leap in anti-ageing”
In a study published in Science, researchers from the University of New South Wales (UNSW) say they have identified a critical step in the molecular process that allows cells to repair damaged DNA, which could potentially lead to a new drug that reverses ageing. The experiments in mice suggest a treatment for DNA damage from ageing and radiation that is so promising, it has attracted the attention of NASA, the authors wrote. The UNSW team identified that nicotinamide adenine dinucleotide (NAD+) – a coenzyme found in all living cells – plays a key role as a regulator in protein-to-protein interactions that control DNA repair. Treating mice with a NAD+ precursor, or “booster,” called nicotinamide mononucleotide (NMN) improved their cells’ ability to repair DNA damage caused by radiation exposure or old age, the authors found. “The cells of the old mice were indistinguishable from the young mice, after just 1 week of treatment,” said lead author Professor David Sinclair of UNSW School of Medical Sciences and Harvard Medical School, Boston. Human trials of NMN therapy will begin within 6 months. “This is the closest we are to a safe and effective anti-ageing drug that’s perhaps only 3–5 years away from being on the market if the trials go well,” he says. NASA’s interest stems from the challenge of keeping astronauts healthy during the 4-year mission to Mars. Even on short missions, astronauts experience accelerated ageing from cosmic radiation, suffering from muscle weakness, memory loss and other symptoms when they return. On a trip to Mars, the situation will be far worse: 5% of the astronauts’ cells will die and their chances of cancer will approach 100%. The other group that could benefit from this work is survivors of childhood cancers. Ninety-six percent of childhood cancer survivors develop a chronic illness by the age of 45 years, including cardiovascular disease, type 2 diabetes, Alzheimer’s disease, and cancers unrelated to the original cancer.
Limited benefit of mosquito monitoring for dengue
In a study, published in PLOS Neglected Tropical Diseases, US scientists have found that mosquito monitoring surveys, traditionally used to predict dengue outbreaks, are largely ineffective. Every year, an estimated 100 million people around the world contract dengue fever, which can be fatal. Dengue is caused by any of four genetically distinct dengue viruses, all spread to humans through the bites of infected mosquitoes — most commonly Aedes aegypti, which is found in northern Queensland. To pinpoint which areas to target with disease intervention programs, researchers and policymakers have traditionally turned to entomological monitoring surveys that offer snapshots of mosquito abundance in communities. The US researchers analysed data collected during two longitudinal studies in Iquitos, Peru. The datasets included both Aedes aegypti mosquito abundance and dengue virus seroconversion among humans. One study spanned the period from 1999 to 2003, the other from 2008 through 2010. In total, entomological observations from 1377 households that contributed data on mosquitos were linked with blood samples taken approximately 6 months apart from 3824 individuals. The researchers found no association between cross-sectional measures of Aedes aegypti abundance and the risk of infection with dengue virus, as measured by the blood tests. Longitudinal indicators fared better, with individuals residing in households with evidence of adult mosquito abundance over time being between 1% and 30% more likely to have seroconverted to dengue virus.
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