Fig. 6
From: CCL5 is essential for axonogenesis and neuronal restoration after brain injury
CCL5 treatment enhanced synaptogenesis and myelination by activating the mTOR signaling pathway and the NGR-ERBB signaling pathway after mTBI. Golgi staining of cortical neurons in sham, TBI, TBI with CCL5 pretreatment (PreL5), and TBI with CCL5 post-treatment (PostL5) groups of mice. A The representative images of neurites and dendritic spines in different groups of mice. Black arrows point to swollen spines. Scale bar = 10 µm. The spine density (B) and the number of swollen spines (C) were quantified in different groups of mice (n = 10 in each group). (B: sham vs TBI, p < 0.0001; TBI vs Pre-L5, p = 0.0447; TBI vs Post-L5, p < 0.0001). (C: sham vs TBI, p < 0.0001; TBI vs Pre-L5, p < 0.0001; TBI vs Post-L5, p < 0.0001) D The expression of synaptic proteins – PSD95 and synaptophysin in KO mice cortex after mTBI with/without CCL5 administration. (D’: PSD95: TBI vs Pre-L5, p = 0.0169; TBI vs Post-L5, p = 0.0008; Synaptophysin: sham vs TBI, p = 0.004; TBI vs Pre-L5, p = 0.0032; TBI vs Post-L5, p = 0.0013; GAP43: TBI vs Pre-L5, p = 0.0079; TBI vs Post-L5, p = 0.0177). Western blot analyzed the expression of E axon-related signaling proteins - Sema3, EIF2, and mTOR phosphorylation. (E’: SEMA3a: TBI vs Pre-L5, p = 0.0193; TBI vs Post-L5, p = 0.0483; p-p70S6T421: TBI vs Pre-L5, p = 0.0121; TBI vs Post-L5, p = 0.0238; p-mTOR: TBI vs Pre-L5, p = 0.0121). F myelination-related proteins - Neuregulin, Erk, and SMI32 (F’: NRG-1: TBI vs Pre-L5, p = 0.0420; TBI vs Post-L5, p = 0.0127; p-ERK1/2: TBI vs Pre-L5, p = 0.0317; TBI vs Post-L5, p = 0.0303); and G FGF signaling - FAK phosphorylation (G’: p-FAK: sham vs TBI, p = 0.0476; TBI vs Pre-L5, p = 0.0476; TBI vs Post-L5, p = 0.0238) in injured cortex in different groups. (n = 4 ~ 5 in each group) H The immunostaining of unmyelinated axon - SMI-32 and oligo-2 in 4 groups of CCL5-KO mouse cortex; arrows point to the Oligo-2 positive cells under the pial surface around the injured cortex. The quantification results were in (J) SMI-32 and (K) oligodendrocytes. (J: sham vs TBI, p < 0.0001; TBI vs Pre-L5, p < 0.0001; TBI vs Post-L5, p < 0.0001). (K: TBI vs Pre-L5, p = 0.0004; TBI vs Post-L5, p = 0.0008). I The immunostaining of Reelin (red, arrows) and CXCR4 (Cyan) in mouse cortex in different groups of mice; the q-PCR quantitative result of CXCR4 in mouse cortex L (L: sham vs TBI, p = 0.0075; TBI vs Pre-L5, p = 0.0047; TBI vs Post-L5, p < 0.0001). Data were analyzed by unpaired t-test. See also Supplementary Fig. 6