IL-1受体相关激酶1和2协同调控IL-1诱导的NF-κB活化

Interleukin-1 receptor associated kinase-1 and -2 synergetically activate NF-κB

目的 研究白细胞介素 1受体相关激酶 1(IRAK 1)和IRAK 2在白细胞介素 1(IL 1)诱导核因子 κB(NF κB)活化中的作用。方法 Lipofectin介导反义IRAK 1寡核苷酸和反义IRAK 2寡核苷酸转染HepG2细胞。用逆转录PCR法检测IRAK 1mRNA和IRAK 2mRNA表达水平 ,以夹心ELISA法检测NF κB的活化。结果 (1)反义IRAK 1寡核苷酸和反义IRAK 2寡核苷酸分别抑制IRAK 1mRNA和IRAK 2mRNA表达。 (2 )反义IRAK 1寡核苷酸或反义IRAK 2寡核苷酸部分抑制NF κB活化 ,最高抑制率分别为 (34 6± 0 9) %和 (5 4 5± 0 2 ) %。 (3)反义IRAK 1寡核苷酸与反义IRAK 2寡核苷酸共转染HepG2细胞对NF κB的抑制作用明显增强 ,抑制率达 (77 5± 0 9) %。结论 IRAK 1或IRAK 2调控NF κB活化 ,但不能完全激活NF κB ;IRAK 1和IRAK 2协同调控IL 1诱导的NF κB活化。

Objective To investigate whether interleukin-1 receptor associated kinase-1 (IRAK-1) and IRAK-2 are functionally synergetic or redundant but differentially expressed in interleukin-1 (IL-1)-induced nuclear factor-κB(NF-κB) activation. Methods Phosphorothioate oligonucleotides (ODN) were designed antisense to sequences of IRAK-1 or IRAK-2. Antisense IRAK-1 ODN or antisense IRAK-2 ODN was delivered by lipofectin encapsulation into cultured HepG2 cells. IRAK-1 mRNA and IRAK-2 mRNA expression were assayed by semiquantitative reverse transcription-PCR. The levels of NF-κB were measured by sandwich ELISA. Results Antisense IRAK-1 ODN and antisense IRAK-2 ODN blocked IRAK-1 and IRAK-2 expression, respectively. As a result, antisense IRAK-1 ODN or antisense IRAK-2 ODN inhibited IL-1-induced NF-κB activation in a dose (1-8μg ) and time (5-24 h) dependent fashion. When the cells were treated with antisense IRAK-1 ODN (4μg) or antisense IRAK-2 ODN (4μg) for 8 h, maximum inhibition rates of 34.6%±0.9% and 54.5%±0.2%, respectively, were observed. Cotransfection of antisense IRAK-1 ODN with antisense IRAK-2 ODN resulted in an additive inhibition of NF-κB-activation by 77.5%±0.9%. Conclusion These data suggest that either IRAK-1 or IRAK-2 is necessary but not sufficient to activate NF-κB and that IRAK-1 regulate IL-1-stimulated NF-κB activation in cooperation with IRAK-2.