The Interaction of Nuclear Factor-Kappa B and Cytokines Is Associated with Schizophrenia

BackgroundMany reports suggest that schizophrenia is associated with the inflammatory response mediated by cytokines, and nuclear factor-kappa B (NF-κB) regulates the expression of cytokines. However, it remains unclear whether the interaction between NF-κB and cytokines is implicated in schizophrenia and whether the effect of neuroleptics treatment for 4 weeks is associated with the alteration of cytokines.MethodsSixty-five healthy subjects and 83 first-episode schizophrenic patients who met DSM-IV criteria and who were never treated with neuroleptics previously were included. Serum levels of cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were examined by using sandwich enzyme immunoassay (EIA). Peripheral blood mononuclear cell (PBMC) mRNA expressions of cytokines (IL-1β, TNF-α) and NF-κB were detected by using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). NF-κB activation was examined by using transcription factor assay kits.ResultsSchizophrenic patients showed significantly higher serum levels and PBMC mRNA expressions of IL-1β and TNF-α compared with healthy subjects. However, treatment with the neuroleptic risperidone for 4 weeks significantly decreased serum levels and PBMC mRNA expressions of IL-1β in schizophrenic patients. NF-κB activation and PBMC mRNA expression in patients were significantly higher than those in healthy subjects. Furthermore, PBMC mRNA expressions of IL-1β and TNF-α were positively correlated to NF-κB activation in both schizophrenic patients and healthy control subjects.ConclusionsSchizophrenic patients showed activation of the cytokine system and immune disturbance. NF-κB activation may play a pivotal role in schizophrenia through interaction with cytokines.