Actin骨架偶联IRAK-NF-κB信号通路参与细菌脂蛋白诱导的交叉耐受  

Coupling of actin with IRAK-NF-κB in bacterial lipoprotein induced cross tolerance in monocytes

作　　者：周荣[1] 刘建仓[1] 刘良明[1] 刘韧[1] 肖南[1] 

机构地区：[1]第三军医大学大坪医院野战外科研究所第二研究室,创伤、烧伤及复合伤国家重点实验室,重庆400042

出　　处：《中国病理生理杂志》2008年第8期1604-1609,共6页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30471791)

摘　　要：目的:采用人单核细胞株(THP-1),建立小剂量BLP诱导THP-1细胞对BLP耐受的细胞模型,观察BLP诱导THP-1细胞对BLP耐受及对LPS交叉耐受时细胞actin骨架的变化情况,并探讨细胞actin骨架在BLP耐受及交叉耐受形成中的作用。方法:采用人单核细胞株THP-1,建立小剂量BLP预处理诱导的BLP耐受细胞模型;采用ELISA法测定炎症因子TNF-α、IL-1β及IL-6浓度;采用FITC标记的鬼笔环肽进行actin骨架染色;采用EMSA法检测NF-κB转录活性。结果:大剂量BLP(100μg/L)及大剂量LPS(100μg/L)孵育6h可诱导THP-1细胞的炎症反应激活,TNF-α、IL-1β及IL-6的释放显著增加,白细胞介素-1受体相关激酶-1(IRAK-1)活性显著增强,NF-κB转录活性明显上调,细胞actin骨架收缩成团块状,细胞形态改变并形成伪足;而用小剂量BLP(10μg/L)预处理12h后,THP-1细胞对大剂量BLP(100μg/L)及大剂量LPS(100μg/L)孵育6h的耐受性均明显增强,炎症因子(TNF-α、IL-1β及IL-6的释放明显减少,IRAK-1激酶活性被显著抑制,NF-κB转录活性明显降低,细胞伪足形成明显减少且形态明显改善,但仍有肌动蛋白聚集呈"团块"样;此外,actin骨架聚集抑制剂鬼笔环肽可取消由小剂量BLP诱导的耐受及交叉耐受,TNF-α、IL-1β、IL-6释放明显升高,IRAK-1激酶活性明显提高,NF-κB转录活性明显上调。结论:细胞骨架actin参与THP-1细胞BLP耐受及BLP交叉耐受的形成,其机制与actin骨架偶联的IRAK-NF-κB信号通路有关。AIM： Tolerance to bacterial wall components, such as bacterial lipoprotein （BLP） and lipopolysaccharide （LPS）, is an adaptive host response. The current study was aimed to explore the role of actin cytoskeleton in BLP - tolerance and BLP cross - tolerance in monocytes. METHODS： Cellular model of BLP - tolerance induced by pre - exposed to low dose BLP was established in human monocyte cell line （ THP - 1 ）. The concentration of proinflananatory cytokines （TNF-α, IL- 1β, IL -6） was measured by ELISA. Actin was stained with FITC -phalladin. The NF - κB DNA binding activity was tested by EMSA. RESULTS ： When THP - 1 cells were insulted with LPS （ 100 μg/L） or BLP （ 100 μg/L）, the cellular morphology changed significantly with the formation of pseudopod and the actin reorganized to form the actin - band, interleukin 1 receptor - associated kinase - 1 （ IRAK - 1 ） activity and NF - κB DNA binding activity upregulated, and the concentration of cytokins （TNF -α, IL - 1 β and IL -6） in supornatant increased. Pretreatment with BLP （ 10 μg/L） improved the morphologic changes and decreased pseudopod formation. IRAK - 1 activity and NF - κB DNA binding activity were downregulated, and the release of cytokins （ TNF - α, IL - 1β and IL - 6） decreased after insuited with BLP （100 μg/L） or LPS （100 μg/L）. Phalladin, a specific actin cytoskeleton reorganization inhibitor, partly abolished the BLP tolerance and BLP cross - tolerance in THP - 1 cells induced by 10 μg/L BLP, reflected by the upregu- lation of IRAK - 1 activity and NF - KB DNA binding activity and the increase in cytokins （ TNF - α, IL - 1β and IL - 6） release. CONCLUSION： Coupled with IRAK - NF - κB signal cascade, actin cytoskeleton plays an important role in BLP tolerance and BLP cross tolerance in THP - 1 cells induced by pretreatment of BLP.

关 键 词：细菌脂蛋白类 交叉耐受 肌动蛋白细胞骨架 THP-1细胞 

分 类 号：R364.5[医药卫生—病理学]