BIN1 modulation in vivo rescues dynamin-related myopathy.

Abstract

The mechanoenzyme dynamin 2 (DNM2) is crucial for intracellular organization and trafficking. <i>DNM2</i> is mutated in dominant centronuclear myopathy (DNM2-CNM), a muscle disease characterized by defects in organelle positioning in myofibers. It remains unclear how the in vivo functions of DNM2 are regulated in muscle. Moreover, there is no therapy for DNM2-CNM to date. Here, we overexpressed human amphiphysin 2 (BIN1), a membrane remodeling protein mutated in other CNM forms, in <i>Dnm2</i>^RW/+ and <i>Dnm2</i>^RW/RW mice modeling mild and severe DNM2-CNM, through transgenesis or with adeno-associated virus (AAV). Increasing BIN1 improved muscle atrophy and main histopathological features of <i>Dnm2</i>^RW/+ mice and rescued the perinatal lethality and survival of <i>Dnm2</i>^RW/RW mice. In vitro experiments showed that BIN1 binds and recruits DNM2 to membrane tubules, and that the BIN1-DNM2 complex regulates tubules fission. Overall, BIN1 is a potential therapeutic target for dominant centronuclear myopathy linked to DNM2 mutations.