Vimentin Promotes Astrocyte Activation After Chronic Constriction Injury.

Vimentin, among the family of the intermediate filament, plays as the organizer of some critical proteins involved in migration, attachment, and cell signaling. In this study, the role of vimentin in chronic constriction injury (CCI) was investigated. Western blot revealed increased protein level of vimentin following CCI, peaking at 7 days. Double immunofluorescent staining showed that vimentin was mostly co-localized with astrocytes, not with neurons or microglia. In vitro, sensory neuronal injury stimulated astrocytes to produce more pro-inflammation cytokines, p-ERK (phosphorylated extracellular signal-regulated protein kinase), and vimentin. However, vimentin knockdown by siRNA (small interfering RNA) reversed the upregulation of p-ERK and vimentin expression and reduced the release of pro-inflammatory cytokines. Overall, stimulated astrocytes might release pro-inflammatory cytokines to promote the development of neuropathic pain via vimentin/ERK signaling.