People with schizophrenia and bipolar disorder have significantly decreased life expectancies. This can often be due to co-morbidities such as heart conditions or metabolic disorders like type 2 diabetes, which stem from problems with insulin signaling. A new study from the lab of Susan Tsunoda, a professor in the Department of Biomedical Sciences, found that a particular micro-RNA that is highly associated with neuropsychiatric disorders like schizophrenia and bipolar disorder, as well as some brain cancers, also plays a key role in insulin signaling and energy homeostasis in flies. Their results were published today in the Proceedings of the National Academy of Sciences. “Our results might help explain why many schizophrenia and bipolar patients also suffer from insulin-based problems as a co-morbidity,” said Tsunoda. Hana Saedi, the paper’s first author and a recent PhD graduate, began the study by looking at the role of the micro-RNA miR-137 in different stress conditions. Using Drosophila, a fruit fly model, she found that those who lacked the gene miR-137 lived for much longer than normal flies when experiencing nutrient stress. These starvation-resistant flies essentially had no insulin receptor activation, which resulted in increased body weight, high triglycerides, low motivation to eat even when starved, and sluggish movement. This abnormal state appears to be the result of too much of an enzyme called phosphatase PTP61F, which is likely regulated by miR-137 in normal conditions. Next, the team would like to identify all relevant targets of this gene in its regulation of insulin signaling and the tissues in which this regulation occurs. Other authors included Senior Research Associate Girma Waro and Fossil Ridge High School student Lea Giacchetta, the first high school student to gain authorship on a paper in the Tsunoda lab.