REVIEW Pericytes Act as Key Players in Spinal Cord Injury

Spinal cord injury results in locomotor impairment attributable to the formation of an inhibitory fi brous scar, which prevents axonal regeneration after trauma. The scarcity of knowledge about the molecular and cellular mechanisms involved in scar formation after spinal cord lesion impede the design of effective therapies. Recent studies, by using state-of-the-art technologies, including genetic tracking and blockage of pericytes in combination with optogenetics, reveal that pericyte blockage facilitates axonal regeneration and neuronal integration into the local neural circuitry. Strikingly, a pericyte subset is essential during scarring after spinal cord injury, and its arrest results in motor performance improvement. The arising knowledge from current research will contribute to novel approaches to develop therapies for spinal cord injury. We review novel advances in our understanding of pericyte biology in the spinal cord. (Am J Pathol 2019, 189: 1327 e 1337; https:// doi.org/10.1016/j.ajpath.2019.03.008)