Objective

Cellular and molecular events occurring in cartilage regions close to injury are poorly investigated, but can possibly compromise the outcome of cell-based cartilage repair. In this study, key functional properties were assessed for cartilage biopsies collected from the central part of traumatic joint lesions (central) and from regions surrounding the defect (peripheral). These properties were then correlated with the quality of the initial cartilage biopsy and the inflammatory state of the joint.

Design

Cartilage samples were collected from knee joints of 42 patients with traumatic knee injuries and analyzed for cell phenotype (by reverse transcriptas-polymerase chain reaction), histological quality, cellularity, cell viability, proliferation capacity, and post-expansion chondrogenic capacity of chondrocytes (in pellet culture). Synovium was also harvested and analyzed for the expression of inflammatory cytokines.

Results

Cartilage quality and post-expansion chondrogenic capacity were higher in peripheral versus central samples. Differences between these 2 parameters were more pronounced in joints with high inflammatory features characterized by >100-fold difference in the mRNA levels of IL6 and IL8 in the corresponding synovium. Peripheral chondrocytes isolated from good- versus bad-quality biopsies expressed higher levels of collagen II/I and aggrecan/versican and lower levels of MMP13 and ADAMTS5. They also exhibited reduced proliferation and enhanced cartilage-forming capacity.

Conclusions

Chondrocytes at the periphery of traumatic lesions better maintain properties of healthy cartilage compared to those isolated from the center, even when derived from bad-quality tissues harvested from highly inflamed joints. Future studies are necessary to investigate the change of functional properties of peripheral chondrocytes over time.

中文翻译：

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人关节软骨组织和从创伤性病变的外周与中部区域分离的软骨细胞的比较。

客观的

发生在接近损伤的软骨区域的细胞和分子事件的研究很少，但可能会影响基于细胞的软骨修复的结果。在这项研究中，评估了从创伤性关节病变的中央部分（中央）和缺损周围区域（外周）收集的软骨活检的关键功能特性。然后将这些特性与初始软骨活检的质量和关节的炎症状态相关联。

设计

从 42 名创伤性膝关节损伤患者的膝关节采集软骨样本，分析细胞表型（通过逆转录聚合酶链反应）、组织学质量、细胞结构、细胞活力、增殖能力和软骨细胞的扩张后成软骨能力（在颗粒培养）。还收获滑膜并分析炎性细胞因子的表达。

结果

外周与中央样本的软骨质量和扩张后软骨形成能力更高。这两个参数之间的差异在具有高炎症特征的关节中更为明显，其特征是相应滑膜中 IL6 和 IL8 的 mRNA 水平差异 > 100 倍。从优质与劣质活检中分离的外周软骨细胞表达较高水平的胶原蛋白 II/I 和蛋白聚糖/多功能蛋白聚糖以及较低水平的 MMP13 和 ADAMTS5。它们还表现出增殖减少和软骨形成能力增强。

结论

与从中心分离的软骨细胞相比，创伤性病变周围的软骨细胞更好地保持健康软骨的特性，即使来自从高度发炎的关节采集的劣质组织也是如此。未来的研究有必要研究外周软骨细胞功能特性随时间的变化。