Interleukin-17 Induces src/MAPK Cascades Activation in Human Renal Epithelial Cell

細胞間白素十七在人類腎臟上皮細胞活化src/MAPK訊息傳遞路徑的角色

林清淵(Ching-Yuang Lin) ； 謝現貴(Hsian-Guey Hsieh)

《Acta Nephrologica》 14卷4期 (2000/10) Pp. 249-249

並列摘要

Departments of Pediatrics、Medical Research and Education, Taipei Veterans General Hospital; Institute of Microbiology & Immunology, National Yang-Ming University, Taipei, Taiwan, R.O.C Interleukin-17 (IL-17) is a T cell derived pro-inflammatory cytokine exhibiting multiple biological activities in a variety of cells. In our previous study, we found that IL-17 expressed early on borderline change of renal allograft rejection by Banff classification either in rat renal allograft model or human renal specimens. Renal epithelial cells are the important targets in renal allograft rejection. The purpose of this study was to explore the signaling pathways by which human interleukin-17 contributed to renal allograft rejection by inducing IL-6,IL-8 and MCP-1 expression in human renal epithelial cells (hRECs). Using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoprecipitation and western blot analysis, we report that the early signaling events triggered by the IL-17 involved tyrosyl phosphorylation of proteins and increasement of the levels of IL-6, IL-8 and MCP-1 in a dose-dependent manner. Tyrosyl phosphorylation of proteins was induced by IL-17 in 1 min and peaked in 5 min. Further, IL-17 induced the phosphorylation of src kinase and mitogen-activated protein (MAP) kinase. Using a specific src kinase inihibitor, pp2, to treat the hRECs before hIL-17 stimulation, we found that pp2 not only inhibited the phosphorylation of src kinase but also inhibited IL-6, IL-8 and MCP-1 mRNA expression, in a dose-dependent manner. Since the transcription factor NF-κB had been reported to be activated by many kinds of cytokine and growth factor. We test whether IL-17 can activate NF-κB binding in hRECs by electrophoretic mobility shift assay (EMSA) assay. The results showed that IL-17 can enhance the binging of protein NF-κB in hRECs. The NF-κB binding complexes formation after IL-17 stimulation in hRECS are composed of P65/P65 homodimers. In order to examine whether activation of NF-κB by IL-17 is mediated through the src kinase, we pretreat the hRECs with src kinase inhibitor before IL-17 stimulation and then investigate the NF-κB activation by EMSA. We demonstrated that PP2 can inhibit NF-κB activation by IL-17 stimulation in hRECs. Furthermore, the inhibition effect was dose-dependent. These findings provide the first evidence that the mechanism of IL-17signaling involves src/MARK cascades activation.