Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden;
Ortho Center Stockholm, Löwenströmska Hospital, 194 89 Upplands Väsby, Sweden.
J Immunol. 2018 Oct 1;201(7):1918-1927. doi: 10.4049/jimmunol.1800486. Epub 2018 Aug 22.
The aim was to assess the activation and association of the NF-κB system across synovial membrane (SM) and articular cartilage (AC) in patients with knee osteoarthritis (OA) and ascertain its potential effects on catabolic mediator expression in advanced OA. SM and AC were obtained from 40 OA patients undergoing total knee arthroplasty and from 19 postmortem control subjects. NF-κB subunit RelA in nuclear and cytosolic fractions and NF-κB1-DNA binding in nuclear extracts was assessed by ELISA, whereas , , , , and gene expression were analyzed by reverse transcriptase-quantitative PCR in tissues. We observed higher SM nuclear RelA protein levels and upregulated NF-κB1-DNA binding in OA patients compared with postmortem controls. However, in AC, lower nuclear RelA levels were observed compared with cytosolic extracts in patients. Nuclear RelA levels correlated positively with NF-κB1-DNA binding in SM and AC in patients. SM and mRNA levels were upregulated, whereas and as well as AC were downregulated in patients compared with controls. In SM, nuclear RelA levels correlated positively with gene expression in patients. A negative correlation was observed between SM nuclear RelA levels and AC NF-κB1-DNA binding, and SM nuclear NF-κB1-DNA binding correlated negatively with AC and mRNA levels in patients. These findings highlight NF-κB-triggered cross-talk and feedback mechanisms between SM and AC in OA. Further, our findings strongly support a role for an activated NF-κB system in the transcriptional mechanism of inflammatory processes, especially in SM of patients with advanced OA.
目的是评估 NF-κB 系统在膝关节骨关节炎 (OA) 患者的滑膜 (SM) 和关节软骨 (AC) 中的激活和关联，并确定其对晚期 OA 中分解代谢介质表达的潜在影响。从接受全膝关节置换术的 40 例 OA 患者和 19 例尸检对照中获得 SM 和 AC。通过 ELISA 评估核和胞质部分的 NF-κB 亚基 RelA 和核提取物中的 NF-κB1-DNA 结合，同时通过逆转录定量 PCR 分析组织中的 、 、 、 和 基因表达。与尸检对照组相比，我们观察到 OA 患者的 SM 核 RelA 蛋白水平升高且 NF-κB1-DNA 结合上调。然而，与患者的胞质提取物相比，AC 中的核 RelA 水平较低。患者的 SM 和 AC 中核 RelA 水平与 NF-κB1-DNA 结合呈正相关。与对照组相比，患者的 SM 和 mRNA 水平上调，而 和 以及 AC 下调。在 SM 中，患者的核 RelA 水平与 基因表达呈正相关。SM 核 RelA 水平与 AC NF-κB1-DNA 结合呈负相关，患者的 SM 核 NF-κB1-DNA 结合与 AC 和 mRNA 水平呈负相关。这些发现突出了 NF-κB 触发的 OA 中 SM 和 AC 之间的串扰和反馈机制。此外，我们的研究结果强烈支持激活的 NF-κB 系统在炎症过程的转录机制中发挥作用，尤其是在晚期 OA 患者的 SM 中。
