Science Concentrates DRUG DEVELOPMENT
Enlisting the brain to treat diabetes Some patients with diabetes inject themselves with insulin multiple times each day to keep their blood sugar at healthy levels. Researchers now report that a single injection of a protein called fibroblast growth factor 1 (FGF1) into the brains of diabetic rodents normalizes the animals’ blood glucose levels for at least 18 weeks (Nat. Med. 2016, DOI: 10.1038/nm.4101). The findings, the scientists say, suggest the brain plays a role in regulating how the liver and muscle handle glucose, and they point to the brain as a possible target for a diabetes therapy with sustained effects. Previous studies have shown that FGF1 plays a role in metabolism. Levels of FGF1 in the blood “go up when you eat and go down when you’re starving,” says Ronald Evans of the Salk Institute for Biological Studies, who was not involved in the new work. In 2014, Evans and colleagues showed that injecting FGF1 into diabetic mice—though not into their brains—restored healthy blood glucose levels for about two days. Michael W. Schwartz of the University of Washington and colleagues wondered if the protein was acting, in part, through About 6 million people circuits in the brain. There are in the U.S. use insulin to receptors for FGF proteins in maintain healthy blood the hypothalamus, a part of the glucose levels, according brain known to regulate hunger to the Centers for Disease and metabolism, says WashingControl & Prevention. ton’s Jarrad M. Scarlett, the new study’s lead author. To find out, the team injected the protein into the brains of rats and mice with type 2 diabetes. Although the exact mechanism is unknown, FGF1 in the brain increases the uptake of glucose by the liver and muscle. But this FGF1 mechanism doesn’t seem to cause hypoglycemia—a condition in which glucose levels drop too low. Diabetic patients have to worry about hypoglycemia when they use insulin because the hormone can push glucose levels below a healthy range. Evans says these results and those from his lab point to a previously unknown mechanism involved in blood glucose regulation that could be exploited for new diabetes therapies. In addition to further studying FGF1’s actions in the brain, Scarlett says, his team is also looking into ways to deliver FGF1 in patients without invasive brain injections. One possibility could be a nasal spray containing the protein.—MICHAEL TORRICE
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C&EN | CEN.ACS.ORG | MAY 30, 2016
Toxic chemicals from fracking wastewater spills can persist in the environment for years at sites such as this one near Bear Den Bay, N.D.
ENVIRONMENT
Fracking waste can persist for years Researchers track toxic elements released from spills in North Dakota In North Dakota’s Bakken region, a boom of hydraulic fracturing, or fracking, has generated nearly 10,000 wells for unconventional oil and gas production. This increased production also has resulted in almost 4,000 reported spills of fracking wastewater. According to a new study, these spills have left soil and surface water in the area contaminated with water carrying radium, selenium, thallium, lead, and other toxic chemicals that can persist for years at unsafe levels (Environ. Sci. Technol. 2016, DOI: 10.1021/acs.est.5b06349). Using fracking in oil and gas production brings up a brine that carries naturally occurring toxic or radioactive elements such as radium and selenium from rock formations. To understand the impact of fracking wastewater spills on the environment, Avner Vengosh of Duke University and his colleagues sampled water, sediment, and soil at sites of reported brine spills, which had occurred months to years earlier. To trace the source of contaminants at those sites, they also analyzed wastewater from shale gas wells in North Dakota and combined it with government data on fracking wastewater. The ratio of strontium-87 to strontium-86 in fracking wastewater carries a distinctive signature of the rock formation where it was produced. By measuring strontium isotopes in the water produced by fracking wells and in water samples taken from spill sites, the researchers could identify brine residue from a spill. At confirmed spill sites, radium, selenium, and thallium exceeded maximum contaminant levels for drinking water in some water samples, and ammonium and selenium concentrations were above recommended levels for aquatic life. In soil and sediment samples downstream from the largest spill site, radium concentrations were up to 100 times as great as concentrations in samples upstream. Brian W. Stewart, a geochemist at the University of Pittsburgh who studies fracking wastewater, says this is the first time, to his knowledge, that systematic sampling has been done downstream of known brine spills to detect the impact of wastewater from fracking. “I was surprised that it persists that long,” he says, pointing to two cases in which the group found elevated levels of contaminants four years after a spill.—DEIRDRE LOCKWOOD, special to C&EN
CREDIT: SHUTTERSTOCK (INSULIN); AVNER VENGOSH (SPILL SITE)
Injection of growth factor into rodent brains normalizes blood sugar for four months
