Longevity & AgingSensory nerves send the growth signals that tell broken bones to heal
Fracture pain travels through sensory nerves, and those same nerves appear to help start bone regeneration. Researchers used single-cell RNA sequencing to profile dorsal root ganglion neurons that innervate mouse bone, before and after a fracture. CGRP+ peptidergic neurons and Aβ-Field low-threshold mechanoreceptors were the most common bone-innervating types. After injury, these neurons shifted their gene expression in step with the phases of bone repair, turning on morphogens including Tgfb1, Fgf9, and Shh. Removing bone innervation impaired healing and was linked to poor proliferation and osteogenic differentiation of mesenchymal cells. The team then identified fibroblast growth factor 9 (FGF9) as a major regulator of fracture repair that might be harnessed therapeutically. The findings are preclinical, but they point to nerve-derived signals as potential targets for improving bone healing.
