Differential protein expression in rat trigeminal ganglia during inflammation

A proteomics approach was used to investigate global protein changes in rat sensory ganglia exposed to pro-inflammatory stimuli. Inflammation was prov oked in vivo by injecting selected facial areas with Freunds Complete Adjuv ant (FCA), or by stimulating freshly isolated trigeminal ganglia ex vivo wi th pro-inflammatory mediators (interleukin-1 beta, tumor necrosis factor-al pha, interferon-gamma). Following two-dimensional gel electrophoresis, silv er staining and mass spectrometry, a protein reference map and database was generated for rat trigeminal ganglia, which to our knowledge is the first to be reported. Sixty-seven out of 85 selected protein spots were successfu lly identified using matrix-assisted laser desorption/ionization mass spect rometry. This reference map was used to monitor changes in the ganglia prot eome induced during inflammation in vivo and ex vivo. In vivo we found that FCA treatment specifically induced differential protein expression of two unidentified protein spots and, to a lower extent, of P-tubulin. Image anal ysis of ganglia treated ex vivo with the cocktail of cytokines indicated th at some of the changes in the protein population were also observed in vivo after FCA treatment. If the cytokine stimulation was performed in the pres ence of acetaminophen (paracetamol), the drug seemed to reverse the effects of cytokine treatment for at least some protein spots, restoring the same protein pattern observed in control samples.