Effect Of Cytokine Response Modifier A On The Expression Of Interleukin-1? Converting Enzyme In Chondrocytes

Object:To investigate the effects of chitosan/pCDNA3.1(+)CrmA on the expression of interleukin-1? converting enzyme(ICE)and interleukin-1?(IL-1?)in chondrocytes.Methods:Rabbit chondrocytes were isolated and cultured.Chondrocytes were treated with PBS,10?g/ml chitosan(CS)and CS/pCDNA3.1(+)CrmA respectively for 6 hours.Then 10ng/ml IL-1? was added into the culture medium.After 48 hours,the messenger RNA and protein expression of ICE and IL-1? in chondrocytes were detected by using real time polymerase chain reaction and western blot analysis.Results:In CS/pCDNA3.1(+)CrmA treated group(0.52±0.09),the mRNA expression of ICE in chondrocytes was significantly inhibited compared with corresponding samples of CS treated group(0.84±0.11,P<0.01)and PBS treated group(1.00± 0.10,P<0.01).ICE protein expression in CS/pCDNA3.1(+)CrmA treated group(0.20±0.03)was markedly lower than CS(0.37±0.05,P<0.01)and PBS treated group(0.44± 0.07,P<0.01)of chondrocytes.There was no significant difference of ICE mRNA and protein expressions in chondrocytes between CS and PBS treated group.Significant difference of IL-1? mRNA expression was found in the three groups.IL-1? mRNA expression level was significantly lower in CS/pCDNA3.1(+)CrmA treated group(0.55± 0.08)than CS(0.69±0.06,P<0.01)and PBS treated group(0.99 ± 0.04,P<0.01)of chondrocytes.IL-1? protein expression level of chondrocytes in CS/pCDNA3.1(+)CrmA treated group(0.23±0.02)was significantly lower than CS(0.45±0.06,P<0.01)and PBS treated group(0.61±0.09,P<0.01)of cells.Significant difference of IL-1? mRNA and protein expression between CS and PBS treated group was also observed(P<0.01).Conclusion:CrmA mediated by chitosan could significantly suppress the mRNA and protein expression of ICE,thus downregulating the expression of IL-1?,which may be one of the mechanisms of CS/pCDNA3.1(+)CrmA in the treatment of osteoarthritic cartilage degeneration.