Papers of the Week

Neuropathic pain is a common, debilitating clinical issue. Here, the weighted gene co-expression network analysis (WGCNA) was used to identify the specific modules and hub genes that are related to neuropathic pain. The microarray data set of a neuropathic rat model induced by tibial nerve transection (TNT), including dorsal root ganglion (DRG) tissues from TNT model (n = 7) and sham (n = 8) rats, was downloaded from the ArrayExpress database (E-MTAB-2260). The co-expression network modules were identified by the WGCNA package. The protein-protein interaction (PPI) network was constructed, and the node with highest level of connectivity in the network were identified as the hub gene. A total of 1,739 genes and seven modules were identified. The most significant module was the brown module, which contained 215 genes that were primarily associated with the biological process of the defense response and molecular function of calcium ion binding. Furthermore, Ccl2, Fos and Timp1 which were identified as the hub genes in the PPI network and two subnetworks separately. The in vivo studies validated that mRNA and protein levels of Ccl2, Fos and Timp1 were upregulated in DRG and spinal cord tissues after TNT. This study offers novel insights into the molecular mechanisms of neuropathic pain in the context of peripheral nerve injury.