ABSTRACT
AIM:To investigate the inhibitory effect of corticosterone(CORT)on lipopolysaccharide(LPS)-induced expression of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)and its relation with xan-thine oxidase(XO).METHODS:An inflammatory model of mouse macrophage RAW 264.7 was established by stimula-ting with LPS.Total cellular protein was extracted after the macrophages were treated with CORT at different concentrations (0~900 μg/L).The protein levels of NLRP3 and caspase-1 were determined by Western blot.According to the treat-ments,the macrophages were divided into control group,LPS group,LPS+CORT group and LPS+allopurinol group.Cell components were extracted at 0,0.5,1,1.5 and 2 h.The protein levels of NLRP3 and XO were determined by Western blot,and the mRNA expression of NLRP3 and XO was detected by real-time PCR.RESULTS: CORT at 700 μg/L and above significantly inhibited the expression of NLRP 3 and the activation of caspase-1 in the macrophages induced by LPS (P<0.05).Compared with LPS group, the expression of NLRP3 and XO in LPS +CORT group was inhibited(P <0.05),and the expression of NLRP3 in LPS+allopurinol group was also reduced(P<0.05).CONCLUSION: High concentration of CORT inhibits the expression of NLRP 3 in LPS-induced mouse macrophages,which is associated with XO. The inhibitory effect of CORT may be related to the reduction of XO expression.