People with type 2 diabetes have lower levels of the microRNA miR-155 in the blood.
Higher levels of a short strand of RNA called miR-155 lower blood sugar levels in mice, suggesting that the microRNA may be useful in treating type 2 diabetes in humans, report Xiaolin Lin of Southern Medical University, Guangzhou, China, and colleagues in a study published in PLOS Genetics.
Despite the rising number of cases of type 2 diabetes worldwide, the underlying mechanisms of the disease, including the role of microRNAs, are poorly understood. A pilot experiment showed that the serum of people with type 2 diabetes had lower levels of miR-155 than healthy subjects, suggesting that miR-155 might be involved in blood sugar control and diabetes. To further explore this observation, the scientists used genetically engineered mice that express too much or too little miR-155. Excess miR-155 leads to low blood sugar levels, improved glucose tolerance and cells that are sensitive to insulin, while an miR-155 deficiency causes high blood sugar, impaired glucose tolerance and insulin resistance. They went on to show that miR-155 produced these effects, at least in part, by dampening the effects of molecules that reduce insulin’s ability to signal cells to take up glucose.
The study shows that miR-155 regulates several aspects of glucose metabolism and is necessary for normal blood sugar levels in mice. This novel discovery increases our understanding of glucose uptake in type 2 diabetes, which is an increasingly common and potentially debilitating disease. Taken together, the findings demonstrate, for the first time, that miR-155 increases insulin sensitivity and that the microRNA may yield potential therapies for diabetes treatment.
Article: MiR-155 Enhances Insulin Sensitivity by Coordinated Regulation of Multiple Genes in Mice, Lin X, Qin Y, Jia J, Lin T, Lin X, Chen L, et al., PLOS Genetics, doi:10.1371/journal.pgen.1006308, published 6 October 2016.