Interference with Myostatin/ActRIIB Signaling as a Therapeutic Strategy for Duchenne Muscular Dystrophy

Since the discovery of the myostatin/ActRIIB signaling pathway 15 years ago, numerous strategies were developed to block its inhibitory function during skeletal muscle growth. Accumulating evidence demonstrates that abrogation of myostatin/ActRIIB signaling ameliorates pathology and function of dystrophic muscle in animal models for Duchenne muscular dystrophy (DMD). Therapeutic trials in healthy man and muscular dystrophy patients suggest feasibility of blockade strategies for potential clinical use. However, many key questions on the effect of myostatin/ActRIIB blockade remain unresolved; such as the underlying molecular mechanism that triggers muscle growth, the effect on muscle regeneration and adult muscle stem cell regulation and whether it causes long term metabolic alterations. Current therapeutic strategies aim to systemically abrogate myostatin/ActRIIB signaling. Although this ensures widespread effect on musculature, it also interferes with ActRIIB signaling in other tissues than skeletal muscle, thereby risking adverse effects. This review discusses current knowledge on myostatin/ActRIIB signaling and its potential value as a therapeutic target for DMD. Keywords: Activin receptor, duchenne muscular dystrophy, mdx mouse, myostatin, skeletal muscle, myostatin/ActRIIB, DMD, MSTN, mdx, Mstn