A role for fibroblast and mural cell subsets in models of neuropathic pain.
Neuropathic pain is a particularly intractable type of chronic pain that can result from physical nerve damage due to surgery or entrapment. Here, we present data which suggest that a particular subclass of fibroblast and mural cells may be implicated in the sensory neuron dysfunction that is characteristic of this pain state.

In a mouse model of traumatic painful neuropathy, we used RNA sequencing, cell sorting and nerve tissue clearing to study mesenchymal lineage cells. We show that Pdgfrb+ fibroblasts and mural cells are increased in number for at least two months post-nerve damage and express high levels of known and putative pro-algesic mediators, which are further upregulated in neuropathy.

We go on to demonstrate that a human nerve pericyte line releases a selection of these pro-algesic mediators at protein level. Moreover, conditioned media from stimulated human pericytes induces intra-cellular changes in human induced pluripotent stem cell derived sensory neurons; these changes (phosphorylation of the transcription factor STAT3) have been previously linked to sensory neuron activation.

In summary, our data indicate that mesenchymal cell abnormalities should be considered when developing novel strategies to tackle neuropathic pain.