Beta-cell maturation is associated with miRNA expression changes

We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fuel supply and to maintain glucose homeostasis by regulating insulin release and proliferation. Islets from 10-day-old rats (P10) (n=4) or 3-month-old male rat (n=4) were taken. Total RNA was extracted and microRNA profiling was performed with miRNA Agilent arrays.