Recovery from paralysis in adult rats using embryonic stem cells

TLDR

We explored the potential of embryonic stem cell–derived motor neurons to functionally replace those destroyed in paralyzed adult rats. We used a phosphodiesterase type 4 inhibitor, dibutyryl cAMP, and glial cell–derived neurotrophic factor in the sciatic nerve to promote axon growth past myelin barriers and guide transplanted embryonic stem cell–derived motor neurons toward muscle. These strategies significantly increased axon extension into ventral roots, enabled axons to reach muscle, form neuromuscular junctions, become physiologically active, and mediate partial recovery from paralysis, demonstrating the first anatomical and functional replacement of a motor neuron circuit in adult mammals. Ann Neurol 2006;60:32–44.

Abstract

Abstract Objective We explored the potential of embryonic stem cell–derived motor neurons to functionally replace those cells destroyed in paralyzed adult rats. Methods We administered a phosphodiesterase type 4 inhibitor and dibutyryl cyclic adenosine monophosphate to overcome myelin‐mediated repulsion and provided glial cell–derived neurotrophic factor within the sciatic nerve to attract transplanted embryonic stem cell–derived axons toward skeletal muscle targets. Results We found that these strategies significantly increased the success of transplanted axons extending out of the spinal cord into ventral roots. Furthermore, transplant‐derived axons reached muscle, formed neuromuscular junctions, were physiologically active, and mediated partial recovery from paralysis. Interpretation We conclude that restoration of functional motor units by embryonic stem cells is possible and represents a potential therapeutic strategy for patients with paralysis. To our knowledge, this is the first report of the anatomical and functional replacement of a motor neuron circuit within the adult mammalian host. Ann Neurol 2006;60:32–44