Abnormal prostaglandin E2 production blocks myogenic differentiation in myotonic dystrophy

► We purify a factor that inhibits the differentiation of myoblasts in DM1 patients. ► We identify this factor as prostaglandin E2 (PGE2). ► Expression of genes in the PGE2 signaling cascade is increased in DM1 myoblasts. ► PGE2 inhibits myogenic differentiation by decreasing intracellular levels of calcium. ► An altered autocrine mechanism may explain the delay in muscle maturation in cDM1.