Schwann cells are axo-protective after injury irrespective of myelination status in mouse Schwann cell–neuron cocultures

Peer reviewed: TrueAcknowledgements: We thank Karin Müller, Martin Lenz, and Filomena Gallo at the Cambridge Centre for Advanced Imaging for assistance with microscopy. We thank Aviva Tolkovsky and Alex Clark for technical suggestions. We thank Peter Brophy for the gift of the periaxin antibody. We thank Claire Jacob for helpful suggestions.Funder: Belgian National Fund for Scientific Research F.R.S. - FNRS; doi: http://dx.doi.org/10.13039/501100002661Funder: University of Cambridge; doi: http://dx.doi.org/10.13039/501100000735Myelinating Schwann cell (SC)–dorsal root ganglion (DRG) neuron cocultures are an important technique for understanding cell–cell signalling and interactions during peripheral nervous system (PNS) myelination, injury, and regeneration. Although methods using rat SCs and neurons or mouse DRG explants are commonplace, there are no established protocols for compartmentalised myelinating cocultures with dissociated mouse cells. There consequently is a need for a coculture protocol that allows separate genetic manipulation of mouse SCs or neurons, or use of cells from different transgenic animals to complement in vivo mouse experiments. However, inducing myelination of dissociated mouse SCs in culture is challenging. Here, we describe a new method to coculture dissociated mouse SCs and DRG neurons in microfluidic chambers and induce robust myelination. Cocultures can be axotomised to study injury and used for drug treatments, and cells can be lentivirally transduced for live imaging. We used this model to investigate axon degeneration after traumatic axotomy and find that SCs, irrespective of myelination status, are axo-protective. At later timepoints after injury, live imaging of cocultures shows that SCs break up, ingest and clear axonal debris