Exosomal cargo including microRNA regulates sensory neuron to macrophage communication after nerve trauma

• DOI: 10.1038/s41467-017-01841-5
• Publication Date: 2017-11-20T18:36:23Z
• Authors: Raffaele Simeoli; Karli Montague; Hefin R. Jones; Laura Castaldi; David Chambers; Jayne H. Kelleher; Valentina Vacca; Thomas Pitcher; John Grist; Hadil Al-Ahdal; Liang-Fong Wong; Mauro Perretti; Johnathan Lai; Peter Mouritzen; Paul Heppenstall; Marzia Malcangio
• Keywords: Sensory neuron; Dorsal root ganglion; Nerve Injury; Capsaicin

Following peripheral axon injury, dysregulation of non-coding microRNAs (miRs) occurs in dorsal root ganglia (DRG) sensory neurons. Here we show that DRG neuron cell bodies release extracellular vesicles, including exosomes containing miRs, upon activity. We demonstrate miR-21-5p is released the exosomal fraction cultured following capsaicin activation TRPV1 receptors. Pure neuron-derived by are readily phagocytosed macrophages which an increase expression promotes a pro-inflammatory phenotype. After nerve injury mice, upregulated neurons and both intrathecal delivery antagomir conditional deletion miR-21 reduce neuropathic hypersensitivity as well extent inflammatory macrophage recruitment DRG. suggest upregulation contribute to neuron-macrophage communication after damage nerve.