摘要
目的探讨铜绿假单胞菌(Pseudomonas aeruginosa,Pa)活菌对不同分化状态的U937细胞表达IL-8的诱导作用及通过蛋白激酶C(PKC)和核因子κB(NF-κB)的调控机理。方法采用ELISA和RT-PCR法,分别对Pa诱导不同分化状态的人单核白血病细胞系U937细胞分泌IL-8及U937细胞IL-8 mRNA表达进行研究,应用Western blot检验IκB及NF-κB的蛋白表达,观察PKC和NF-κB活化抑制剂对IL-8表达的影响。结果Pa可促进U937细胞及佛波酯(PMA)分化的U937细胞IL-8 mRNA的表达及IL-8的分泌,而且具有明显的量效和时效关系。Pa能直接诱导并迅速活化NF-κB,1h达到高峰,以后逐渐下降。PKC阻断剂calphostin C及NF-κB阻断剂PDTC均能显著抑制NF-κB的活化及IL-8的表达(P<0.01)。结论IL-8的产生可能与U937细胞的分化状态有关;Pa可能通过PKC信号通路促进NF-κB的活化,从而启动IL-8的高效表达和分泌。
Objective To study IL-8 expression of human monecytic leukemia cell lines （ U937 cells） directly induced by Pseudomonas aeruginosa （Pα） and its mechanism through protein kinase C （PKC） and nuclear factor-kappa B （NF-κB）. Methods RT-PCR and ELISA were performed to test the expression of IL-8 in differently differentiated U937 cells infected by Pα. Western blot was employed to examine the expression of NF-κB protein. In addition, U937 cells or PMA（phorbol 12-myristate 13-acetate）-differentiated U937 cells were cultured together with PKC inhibitor, calphostin C, or NF-κB inhibitor, PDTC（ pyrrolidine dithiocarbamate）, respectively before Pa infection, then the expression of IL-8 and NF-κB were assayed using above methods. Results Pa was able to induce IL-8 mRNA expression and IL-8 protein secretion both in U937 cells and in PMA-differentiated U937 cells in marked time and concentration-dependent manner. Pa could also significantly promote the activation of NF-κB, which peaked at 1 h and then went down. PDTC and calphostin C could significantly decrease the activation of NF-κB and the expression of IL-8. Conclusion IL-8 production induced by Pa might relate to the differendated state of U937 cells. The directly induction of Pa could promote the activation of NF-κB by PKC signal pathway, leading to the expression and secretion of IL-8.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
2007年第12期1122-1126,共5页
Chinese Journal of Microbiology and Immunology
