Pap T, van der Laan W H, Aupperle K R, Gay R E, Verheijen J H, Firestein G S, Gay S, Neidhart M
WHO Collaborating Center for Molecular Biology and Novel Therapeutic Strategies for Rheumatic Diseases, University Hospital, Zurich, Switzerland.
Arthritis Rheum. 2000 Nov;43(11):2531-6. doi: 10.1002/1529-0131(200011)43:11<2531::AID-ANR21>3.0.CO;2-V.
To determine the role of chondrocytes and factors released from chondrocytes in cartilage destruction by fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA).
RA FLS from 2 patients were implanted into SCID mice, together with fresh articular cartilage or with cartilage that had been stored for 24 hours at 4 degrees C or at 37 degrees C. The invasion of the same RA FLS into the fresh and stored cartilage was compared histologically using a semiquantitative scoring system. In addition, we investigated whether protein synthesis in chondrocytes affects the invasion of RA FLS in vitro. A 3-dimensional cartilage-like matrix formed by cultured chondrocytes was labeled with 35S. After formation of the cartilage-like matrix, protein synthesis was blocked with cycloheximide. The invasion of RA FLS from 6 patients into cycloheximide-treated and untreated matrix was assessed by measuring the released radioactivity in coculture with and without interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha).
The SCID mouse experiments showed a significant invasion of RA FLS into the cartilage (overall mean score 3.2) but revealed significant differences when the invasion of the same RA FLS into fresh and stored cartilage was compared. RA FLS that were implanted with fresh articular cartilage showed a significantly higher invasiveness than those implanted with pieces of cartilage that had been stored for 24 hours (overall mean score 2.3). Storage at 37 degrees C and 4 degrees C resulted in the same reduction of invasion (35% and 37%, respectively). In the in vitro experiments, RA FLS rapidly destroyed the cartilage-like matrix. Blocking of chondrocyte protein biosynthesis significantly decreased the invasion of RA FLS, as shown by a decreased release of radioactivity. Addition of IL-1beta, but not TNFalpha, to the cocultures partially restored the invasiveness of RA FLS.
These data underline the value of the SCID mouse in vivo model of rheumatoid cartilage destruction and demonstrate that chondrocytes contribute significantly to the degradation of cartilage by releasing factors that stimulate RA FLS. Among those, IL-1beta-mediated mechanisms might be of particular importance.
确定软骨细胞以及软骨细胞释放的因子在类风湿关节炎（RA）患者来源的成纤维样滑膜细胞（FLS）所致软骨破坏中的作用。
将2例患者的RA FLS与新鲜关节软骨或在4℃或37℃保存24小时的软骨一起植入重症联合免疫缺陷（SCID）小鼠体内。使用半定量评分系统对相同的RA FLS在新鲜软骨和保存软骨中的浸润情况进行组织学比较。此外，我们在体外研究了软骨细胞中的蛋白质合成是否会影响RA FLS的浸润。用35S标记由培养的软骨细胞形成的三维软骨样基质。在软骨样基质形成后，用放线菌酮阻断蛋白质合成。通过测量在有和没有白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNFα）的共培养中释放的放射性，评估6例患者的RA FLS对经放线菌酮处理和未处理的基质的浸润情况。
SCID小鼠实验显示RA FLS对软骨有明显浸润（总体平均评分为3.2），但比较相同的RA FLS在新鲜软骨和保存软骨中的浸润情况时发现有显著差异。植入新鲜关节软骨的RA FLS的侵袭性明显高于植入保存24小时软骨片的RA FLS（总体平均评分为2.3）。在37℃和4℃保存导致浸润减少程度相同（分别为35%和37%）。在体外实验中，RA FLS迅速破坏软骨样基质。如放射性释放减少所示，阻断软骨细胞蛋白质生物合成显著降低了RA FLS的浸润。在共培养物中添加IL-1β而非TNFα可部分恢复RA FLS的侵袭性。
这些数据强调了类风湿性软骨破坏的SCID小鼠体内模型的价值，并表明软骨细胞通过释放刺激RA FLS的因子对软骨降解有显著贡献。其中，IL-1β介导的机制可能尤为重要。
