GSE139103
scRNAseq analysis of mouse  L4  whole dorsal root ganglions with and without sciatic nerve crush injury
Peripheral sensory neurons with cell body in dorsal root ganglia (DRG) switch to a regenerative state after nerve injury to enable axon regeneration and functional recovery. Studies of nerve injury responses in sensory neurons have revealed signaling and transcriptional mechanisms that increase their intrinsic regenerative capacity. However, the extent to which satellite glial cells (SGC), which completely surround the neuronal soma contribute to these responses remains unexplored. Using single cell RNA-seq, we defined the transcriptional profile of SGC in naïve and injured conditions and identified Fabp7, also known as BLBP, as a novel marker of SGC. We report that nerve injury elicits gene expression changes in SGC, which are mostly related to lipid metabolism, specifically fatty acid synthesis and the peroxisome proliferator-activated receptor (PPAR) signaling. Conditional deletion of Fatty acid synthase (Fasn), the key enzyme in de novo fatty acid synthesis, specifically in SGC, impairs axon regeneration. Treatment with fenofibrate, a PPARa agonist, rescues the impaired regeneration, suggesting that PPRAa, which belongs to a family of lipid regulated transcription factors, functions downstream of fatty acid synthesis in SGC to promote axon regeneration. These results unravel fatty acid synthesis in SGC as a fundamental novel mechanism mediating axon regeneration in mature peripheral nerves. Overall design: We have applied the high-throughput single-cell mRNA sequencing technique, using the Chromium Single Cell Gene Expression Solution (10x Genomics) to mouse L4 DRG in naïve and injured conditions (3 days post sciatic nerve crush injury), 2 biological replicates for each sample.