News of Note—A genetic approach to diabetes; brain signals and obesity; boosting the immune response to TB

Studying a single family with two insulin-related disorders uncovered a gene defect that could lead to new diabetes treatments.

Newly discovered gene defect could point to diabetes treatments

Scientists at Queen Mary University of London, University of Exeter and Vanderbilt University have uncovered a defect in a gene called MAFA, which governs the production of insulin. They found it by studying a single family that has experienced two types of insulin-related disorders: Some family members have diabetes, while others have insulin-producing tumors in their pancreases that cause low blood sugar. Although genetic diabetes is rare, the researchers believe their discovery could lead to new ways of regenerating insulin-producing beta cells. That, in turn, could spark ideas for new treatments for the much more common Type 1 and Type 2 diabetes. Their research is published in the journal PNAS. (Release)

How brain cell signaling affects obesity

Antennalike structures emanating from neurons emit signals that control the brain’s ability to regulate body weight, according to a new study from the University of California at San Francisco. The structures, called primary cilia, are known to play some role in hormone signaling, but the UCSF scientists were able to prove they also collect a protein called MC4R. The gene that produces this protein is involved in the brain’s hunger circuit, and mutations in it are a common driver of obesity. The UCSF researchers determined that if a genetic mutation prevents MC4R from reaching the cilia, the brain fails to detect signals that would normally cause it to tamp down appetite. The study was published in the journal Nature Genetics. (Release)

Reprogramming immune cells to fight infectious diseases

Scientists at the Research Institute of the McGill University Health Centre and the University of Montreal have figured out how to enhance genetic pathways that trigger an innate immune response to tuberculosis. They worked with the currently available vaccine against the disease, BCG, which has limited effectiveness. But when they gave the vaccine to mice in a way that allowed the bone marrow to access it, BCG reprogrammed the stem cells that generate immune cells. The vaccine “educated” the stem cells so they would generate macrophages, white blood cells that kill TB. They believe their findings, published in the journal Cell, can be used to generate more effective vaccines for TB and other infectious diseases. (Release)