Fig. 3

Illustration of possible ways in which the PNS can regulate bone regeneration following trauma. a Structure of peripheral nerves and nerve-resident cells involved in bone regeneration. b The PNS regulates bone regeneration in two main ways: neuropeptides or neurotransmitters and nerve-resident cells. Neuropeptides or neurotransmitters can be secreted by injured and activated nerve fibers. Nerve-resident cells, mainly SCs and endoneurial mesenchymal cells, alter their transcription and translation, changing their ordinary phenotype to a reparative one, which is similar to their precursor cells (these cells have a common origin from NCCs) after nerve injury. Repair SCs can secrete regulatory molecules, such as oncostatin M and PDGF-AA, to promote regeneration, and endoneurial mesenchymal cells in injured nerves differentiate into bone-lineage cells. The development of inflammation, the invasion of newly formed vessels, the differentiation of osteogenesis and osteoclastogenesis are all regulated by these responses of the PNS after bone trauma