Nihon University Graduate School of Dentistry, 1-8-13, Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
Cytokine. 2011 Nov;56(2):376-86. doi: 10.1016/j.cyto.2011.08.015. Epub 2011 Aug 31.
Interleukin (IL)-17, a proinflammatory cytokine, is produced primarily by activated Th17 cells. IL-17 consists of six ligands that signal through five receptors (IL-17Rs); IL-17A and IL-17F share the highest homology in the family. Matrix metalloproteinases (MMPs) degrade the extracellular matrix during cartilage remodeling whereas tissue inhibitor of metalloproteinases (TIMPs) inhibit the action of MMPs. In the present study, we examined the effect of IL-17F on the degradation and synthesis of the extracellular matrix in cartilage using human articular chondrocytes. We examined the effect of IL-17F on the expression of IL-17Rs, MMPs, TIMPs, type II collagen, aggrecan, link protein, and cyclooxygenases (COXs), as well as on prostaglandin E2 (PGE2) production. We also examined the indirect effect of PGE2 on the above IL-17F-induced/reduced components using NS-398, a specific inhibitor of COX-2. Cells were cultured with or without IL-17F in the presence or absence of either an IL-17R antibody or NS-398 for up to 28 days. Expression of IL-17Rs, MMPs, TIMPs, type II collagen, aggrecan, link protein, and COXs at mRNA and protein levels was determined using real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. PGE2 production was determined by ELISA. The expression of all types of IL-17Rs was detected in chondrocytes. However, IL-17RE expression was extremely low, compared with other IL-17Rs. The expression of MMP-1, MMP-3, MMP-13, and COX-2 as well as PGE2 production were increased by addition of IL-17F, whereas the expression of IL-17RD, TIMP-2, TIMP-4, type II collagen, aggrecan, link protein, and COX-1 was decreased. The expression of IL-17RA, IL-17RB, IL-17RC, MMP-2, MMP-14, TIMP-1, and TIMP-3 was unaffected by addition of IL-17F. The IL-17R antibody blocked the stimulating/reducing effect of IL-17F on the expression of MMP-1, MMP-3, MMP-13, TIMP-2, TIMP-4, type II collagen, aggrecan, and link protein. NS-398 blocked the reducing effect of IL-17F on aggrecan expression, whereas it did not completely block the stimulating/reducing effects of IL-17F on the expression of MMP-1, MMP-3, MMP-13, TIMP-2, TIMP-4, type II collagen, and link protein. Our results suggest that IL-17F stimulates cartilage degradation by increasing the expression of collagenases (MMP-1 and -13) and stromelysin-1 (MMP-3) and by decreasing expression of their inhibitors (TIMP-2 and -4), type II collagen, aggrecan, and link protein in chondrocytes. Furthermore, our results suggest that the expression of aggrecan, link protein, and TIMP-4 decrease through the autocrine action of PGE2 in chondrocytes.
白细胞介素 (IL)-17 是一种促炎细胞因子，主要由激活的 Th17 细胞产生。IL-17 由六个通过五个受体 (IL-17R) 信号传递的配体组成；IL-17A 和 IL-17F 在家族中具有最高的同源性。基质金属蛋白酶 (MMPs) 在软骨重塑过程中降解细胞外基质，而组织金属蛋白酶抑制剂 (TIMP) 则抑制 MMP 的作用。在本研究中，我们使用人关节软骨细胞研究了 IL-17F 对软骨细胞外基质降解和合成的影响。我们研究了 IL-17F 对 IL-17R、MMPs、TIMP、II 型胶原、聚集蛋白聚糖、连接蛋白和环氧化酶 (COXs) 的表达以及前列腺素 E2 (PGE2) 产生的影响。我们还使用 COX-2 的特异性抑制剂 NS-398，研究了 PGE2 对上述 IL-17F 诱导/减少成分的间接影响。细胞在存在或不存在 IL-17R 抗体或 NS-398 的情况下，与或不与 IL-17F 一起培养，长达 28 天。使用实时聚合酶链反应和酶联免疫吸附测定 (ELISA) 分别测定 II 型胶原、聚集蛋白聚糖、连接蛋白和 COXs 的 mRNA 和蛋白质水平的表达。通过 ELISA 测定 PGE2 的产生。在软骨细胞中检测到所有类型的 IL-17R 的表达。然而，与其他 IL-17R 相比，IL-17RE 的表达极低。添加 IL-17F 后，MMP-1、MMP-3、MMP-13 和 COX-2 的表达以及 PGE2 的产生增加，而 IL-17RD、TIMP-2、TIMP-4、II 型胶原、聚集蛋白聚糖、连接蛋白和 COX-1 的表达减少。添加 IL-17F 对 IL-17RA、IL-17RB、IL-17RC、MMP-2、MMP-14、TIMP-1 和 TIMP-3 的表达没有影响。IL-17R 抗体阻断了 IL-17F 对 MMP-1、MMP-3、MMP-13、TIMP-2、TIMP-4、II 型胶原、聚集蛋白聚糖和连接蛋白表达的刺激/减少作用。NS-398 阻断了 IL-17F 对聚集蛋白聚糖表达的减少作用，但并没有完全阻断 IL-17F 对 MMP-1、MMP-3、MMP-13、TIMP-2、TIMP-4、II 型胶原和连接蛋白表达的刺激/减少作用。我们的结果表明，IL-17F 通过增加胶原酶 (MMP-1 和 -13) 和基质金属蛋白酶 1 (MMP-3) 的表达，减少其抑制剂 (TIMP-2 和 -4)、II 型胶原、聚集蛋白聚糖和连接蛋白的表达，从而刺激软骨降解。此外，我们的结果表明，软骨细胞中聚集蛋白聚糖、连接蛋白和 TIMP-4 的表达通过 PGE2 的自分泌作用减少。
