Satellite Glial Cells in Sensory Nervous System Health, Injury and Disease

Dr. Cavalli will introduce sensory neurons in dorsal root ganglia (DRG). They send a single axon which bifurcates within the ganglion; one axon proceeds centrally along the dorsal root into the spinal cord and the other proceeds along peripheral nerves. Whereas regeneration and functional recovery can occur after peripheral nerve injury, dorsal root injury or spinal cord injury is not followed by regenerative outcomes. Regeneration of sensory axons in peripheral nerves is not entirely cell autonomous. Whether the DRG microenvironment influences the different regenerative capacities after injury to peripheral or central axons remains largely unknown. To answer this question, Dr. Cavalli performed a single cell transcriptional profiling of mouse DRG in response to peripheral (sciatic nerve crush) and central axon injuries (dorsal root crush and spinal cord injury). Activation of the PPARalpha signaling pathway in satellite glial cells (SGC), which promotes axon regeneration after peripheral nerve injury, fails to occur after central axon injuries. Using the PPAR-alpha agonist fenofibrate, an FDA-approved compound used to treat dyslipidemia, axon regeneration after dorsal root crush was increased. Our findings that the repair pathways we identified in mouse models of SGC are present in human SGC holds great promise for potential therapy in humans.