The role of muscle LIM protein in the nervous system

Unlike the peripheral nervous system (PNS), the central nervous system (CNS) has a low intrinsic regenerative capacity and has mechanisms that actively suppress axon regrowth, for example, glial scarring and myelin inhibition (Fischer, 2012). Even in the PNS, which has the principle ability to regenerate injured axons, functional recovery remains limited, particularly in cases where the nerve target has become unreceptive to re-innervation over time due to an insufficient axonal growth rate (Diekmann and Fischer, 2015). Progress towards robust neuroregenerative therapies depends upon an understanding of the relevant signaling and cytoskeletal proteins that drive and control axon extension. Muscle LIM protein (MLP), also known as cysteine and glycine-rich protein 3, was recently discovered to be one such protein that is expressed in regenerating rat neurons and whose overexpression can promote the axon regeneration of adult central, and peripheral neurons of different species (Levin et al., 2019).