Effects of cholecystokinin octapeptide on TNF- α- induced IL- 6 expression and its possible molecular mechanismin rat synovial cell strain RSC-364 / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effect of sulfated cholecystokinin octapeptide (CCK -8 ) on TNF -α induced IL - 6 mRNA expression, NF - κB activation in the rat fibroblast - like synovial cell strain RSC - 364 and its possible receptor mechanisms. METHODS: RSC -364 cells were stimulated with TNF - α( 10 μg/L) in the presence or absence of sCCK- 8( 10-8 - 10-6 mol/L) or/and CCK receptor antagonist proglumide(2 mg/L). IL -6 and CCK receptor A/B (CCK- AR/CCK/BR) mRNA expression were assayed by reverse transcription polymerase chain reaction (RT- PCR) at 3 h after stimulation, and nuclear factor - κB (NF - κB) binding activity was analyzed by electrophoretic mobility shift assay (EMSA) at lh after stimulation. At 30 min of stimulation the IκB protein level in cytoplasma was measured by Western blotting. RESULTS: Both CCK - AR and CCK - BR were constitutively expressed on RSC - 364. sCCK - 8, at concentrations from 10-8 mol/L to 10 -6 mol/L, significantly increased IL - 6 mRNA expression, CCK - AR and CCK - BR mRNA expression, NF - κB binding activity and IκB protein degradation. The effects of sCCK - 8 on NF - κB activity and IκB degradation level were attenuated by CCK receptor antagonist proglumide. CONCLUSION: sCCK - 8 upregulats TNF - α- induced IL - 6 mRNA expression by NF - κB pathway through its receptor on rat synoviocytes, suggesting its possible regulatory role in the pathogenesis of rheumatoid arthritis.