激素敏感型单纯性肾病病毒基因反式激活过程中核因子κB活化及IκBα表达研究

STUDY ON THE ACTIVATION OF NUCLEAR FACTOR-KAPPA B AND EXPRESSION OF INHIBITORY-KAPPA B ALPHA DURING VIRAL TRANSACTIVATION OF TRANSCRIPTION IN STEROID RESPONSIVE SIMPLE NEPHROTIC SYNDROME

[目的]研究核因子κB(nuclear factor-kappa B alpha,NF-κB)及抑制子κBα(inhibitory kappaB alpha,IκB)α在激素敏感型单纯性肾病(responsive simple nephrotic syndrome,SRSNS)病毒基因反式激活中的作用。[方法]采用电泳迁移率改变实验、RT-PCR和ELISA分别测定SRSNS、肾炎性肾病、继发性肾小球疾病、毛细支气管炎和正常儿童外周血单个核细胞(peripheral blood mononuclear cells PBMCs)中NF-κB活性、呼吸道病毒基因和血浆病毒抗体;实时定量RT-PCR、Western blot和ELISA分别检测SRSNS和正常儿童IκBα基因表达、蛋白质表达和血浆IL-8水平。[结果]与SRSNS缓解期和其他组比较,SRSNS活动期NF-κB活性明显增加。NF-κB活性与呼吸道病毒检出阳性率呈正相关趋势。SRSNS活动期血浆IL-8水平增高,并且与NF-κB活性呈直线正相关关系。SRSNS活动期IκBα蛋白质低于SRSNS缓解期患儿和正常儿童,与NF-κB活性呈直线负相关。而SRSNS活动期IκBαmRNA水平高于正常儿童,但仍低于SRSNS缓解期患儿。[结论]病毒基因反式激活过程中NF-κB活化及IκBα蛋白质表达降低可能是呼吸道病毒触发SRSNS主要机制之一。

Objective] To investigate the role of nuclear factor-kappa B （NF-κB） and inhibitory kappaB alpha （ IκBα） during viral transactivation of transcription in steroid responsive simple nephrotic syndrome （SRSNS） . [Methods] Children with SRSNS （including active stage and remissive stage） were examined, and were compared to children with nephritic nephrosis, secondary glomerular diseases, bronchiohtis and healthy children. Electro-mobility shift assays, RT-PCR and ELISA were used to detect the activity of NF-κB. the gene expression of respiratory tract viruses （including respiratory syncytial virus and influenza virus） in peripheral blood mononuclear cells （PBMCs） and the level of viral antibody in plasma, respectively. The mRNA and protein level of IκBα and the level of IL-8 were measured through real-time RT-PCR, Western blot and ELISA in SRSNS at active stage and healthy children. [ Results] Compared with that from SRSNS at remissive stage and other groups, the activity of NF-κB from SRSNS at active stage was much higher statistically. And there was a positive correlation trend between the activity of NF-κB and the gene expression of respiratory tract viruses in SRSNS at actkive stage. Compared with that from healthy children., the level of IL-8 from SRSNS at active stage was significantly increased. There was a positave correlation between the activity of NF-kB and the level of IL-8. The protein level of IκBα from SRSNS at active stage was much lower than that from healthy children and that from SRSNS at remissive stage. There was a linear negative correlation between the activity of NF-κB and the protein level of IκBα. On the other hand, the mRNA level of IκBα from SRSNS at active stage was much higher than that from healthy children, but much lower than that from SRSNS at remissive stage. [Conclusion] The activation of NF- κB and decreased protein level of IκBα during viral transactivation of transcription may play a key role in the pathogenesis of SRSNS triggered by respiratory tract viruses.