Adjuvant-induced arthritis: IL-1 beta, IL-6 and TNF-alpha are up-regulated in the spinal cord

Abstract

Adjuvant-induced arthritis (AIA) is a widely used animal model of human rheumatoid arthritis (RA). We have previously shown that increased neuropeptide expression is observed in the spinal cord of AIA rats. To study the potential role of cytokines in the spinal cord of AIA, we wanted to determine whether there are changes of glial and cytokine expression (IL-1 beta, IL-6, TNF-alpha and IFN-gamma) in the spinal cord of AIA rats. Our data indicated that macroglia and MHC class II immunostaining were enhanced, astrocytes expressing GFAP were increased in number and immunostaining intensity. Using in situ hybridization and immunohistochemical methods, both mRNA and protein levels of IL-1 beta, IL-6 and TNF-alpha were significantly increased in the spinal cord of arthritic rats. Increased cytokine expression was presented in the reactive astrocytes and microglia.