Dun et al. show that after peripheral nerve injury, macrophages form the outermost layer of the nerve bridge and secrete Slit3. Migrating Schwann cells inside the nerve bridge express the Robo1 receptor. The Slit3-Robo1 repulsive signaling between macrophages and Schwann cells plays a critical role in adult peripheral nerve regeneration.
Dun, X. peng, Carr, L., Woodley, P. K., Barry, R. W., Drake, L. K., Mindos, T., … Parkinson, D. B. (2019). Macrophage-Derived Slit3 Controls Cell Migration and Axon Pathfinding in the Peripheral Nerve Bridge. Cell Reports, 26(6), 1458-1472.e4. https://doi.org/10.1016/j.celrep.2018.12.081