Nat. Neurosci. https://doi.org/10.1038/s41593-018-0324-9 (2018)

Clearance of myelin debris at the site of spinal cord injury (SCI) is critical for axon regeneration, remyelination and resolution of inflammation. In Nature Neuroscience, Ren and colleagues use mouse models of SCI to show that endothelial cells in the lining of microvessels, which form early in the epicenter of the lesion, engulf and degrade myelin debris. Brain microvascular endothelial cells (BMECs) engulf myelin much more slowly than do macrophages, require opsonization of myelin via immunoglobulin IgG and use the autophagy–lysosomal pathway for the degradation of myelin. Engulfment of myelin increases the expression of genes encoding inflammatory cytokines and chemokines (Il4, Il6, Ccl2 and Nos2) and those encoding molecules involved in autophagy (Atg3, Atg5 and Gabarap12) and downregulates the expression of genes encoding molecules involved in angiogenesis (Notch, adhesion and cell junction). Injection of myelin-fed BMECs at the site of SCI promotes angiogenesis, the recruitment and activation of macrophages and the deposition of collagen I and fibronectin.