RESUMO
Objective To investigate the effect and mechanism of astragalusⅣ (AS-Ⅳ) on the expression of CCL18in U937macrophages.Methods The expression of CCL18mRNA was detected by real time PCR.The expression of CCL18protein was assessed by Elisa.The expression of IL-4receptor was measured by flow cytometry.The STAT 6phosphorylation was measured by Elisa.The activity of JAK kinase was detected by Z″-LYTETMkinase assay.Results AS-Ⅳsignificantly down-regulated the expression of CCL18in U937macrophages stimulated by IL-4with a dose-dependent manner.However, AS-Ⅳhad no significant effect on IL-4receptor subunit expression.The STAT6phosphorylation was inhibited by AS-Ⅳ, but the effect was less than AS1517499;the activity of JAK1, JAK3and TYK2kinase were inhibited by AS-Ⅳ.Conclusion AS-Ⅳcould inhibit the expression of CCL18in U937macrophages stimulated by IL-4.One of the suggested mechanisms was due to inhibition of JAK kinase activity, which caused STAT6transcriptional activity down and inhibited CCL18gene expression.