The Xist Factor, Black Lung Epidemic (Abstract Science: Feb. 19-23)
A spike in black lung disease hits Central Appalachia, an innovative treatment for the rare Rett disease, and mapping our massive overfishing
(GEN, 2/20/18, Monique Brouillette)
You might say women have the advantage when it comes to sex chromosomes, because instead of one X, they have two. Scientists have recently been looking to this extra genetic material to advance the treatment of genetic diseases originating on the X. The idea is that if one chromosome has a defective gene, the healthy one can step up and take over. The only problem is that in females, about half of the X’s are unavailable due to a mysterious process called X inactivation. How this happens has long been a mystery, but recent discoveries have revealed that RNA plays a central role. A molecule of RNA called the X-inactive-specific transcript or Xist (pronounced “exist”) recruits epigenetic factors, including those that methylate DNA, to the chromosome to render it inactive. In a paper recently published in PNAS, a group of scientists at Harvard Medical School show that by blocking Xist RNA and adding a small-molecule drug that de-methylates DNA, they can reactivate genes on the X chromosome, including one central to Rett syndrome, a devastating neurodevelopmental disease caused by a mutation on the X chromosome.
(New York Times, 2/22/18, Nadja Popovich)
A new black lung epidemic appears to be emerging in central Appalachia, driven by miners breathing in more silica dust, the likely result of a decades-long shift toward mining thinner coal seams that require cutting into the surrounding rock. Silica dust from pulverized rock can damage lungs faster than coal dust alone. Federal investigators identified the cluster earlier this month in a letter appearing in the Journal of the American Medical Association. The scientists from the National Institute for Occupational Safety and Health said that more than 400 coal miners frequenting three clinics in southwestern Virginia between 2013 and 2017 were found to have complicated black lung disease, an extreme form characterized by dense masses of scar tissue in the lungs. The severity of the disease among miners at the Virginia clinics “knocked us back on our heels,” said David J. Blackley, an epidemiologist at the Institute.
(Washington Post, 2/22/18, Chris Moony and Brady Dennis)
We’ve all heard stories about overfishing in the world’s oceans. A mapping effort led by Global Fishing Watch, and published this week in Science, shows that humans are now fishing at least 55 percent of the world’s oceans — an area four times larger than the area occupied by humanity’s onshore agriculture. “Fishing is happening almost everywhere and all the time,” said Jackie Savitz, chief policy officer for the advocacy group Oceana. “I think people don’t really have a sense of how heavily fished our oceans are and how intensely they are fished.”
—Compiled by Senior Scientific Writer Regina McEnery