Objective

There is a need to incorporate multiple tissues into in vitro OA models to evaluate novel therapeutics. This approach is limited by inherent donor variability. We present an optimized research tool: a human OA cartilage-synovium explant co-culture model (OA-EXM) that employs donor-matched lower and upper limit response controls combined with statistical approaches to address variability. Multiple rapid read-outs allow for evaluation of therapeutics while cataloguing cartilage-synovium interactions.

Design

48-h human explant cultures were sourced from OA knee arthroplasties. An OA-like cartilage-synovium co-culture baseline was established relative to donor-matched upper limit supraphysiological pro-inflammatory cytokine and lower limit OA cartilage or synovium alone controls. 100 nM dexamethasone treatment validated possible “rescue effects” within the OA-EXM dual tissue environment. Gene expression, proteoglycan loss, MMP activity, and soluble protein concentrations were analyzed using blocking and clustering methods.

Results

The OA-EXM demonstrates the value of the co-culture approach as the addition of OA synovium increases OA cartilage proteoglycan loss and expression of MMP1, MMP3, MMP13, CXCL8, CCL2, IL6, and PTGS2, but not to the extent of supraphysiological stimulation. Conversely, OA cartilage does not affect gene expression or MMP activity of OA synovium. Dexamethasone shows dual treatment effects on synovium (pro-resolving macrophage upregulation, protease downregulation) and cartilage (pro-inflammatory, catabolic, and anabolic downregulation), and decreases soluble CCL2 levels in co-culture, thereby validating OA-EXM utility.

Conclusions

The OA-EXM is representative of late-stage OA pathology, captures dual interactions between cartilage and synovium, and combined with statistical strategies provides a rapid, sensitive research tool for evaluating OA therapeutics.

中文翻译：

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使用人软骨-滑膜外植体共培养的多变量分析评估新型骨关节炎疗法的工具

客观的

需要将多种组织纳入体外OA 模型以评估新的治疗方法。这种方法受到固有供体可变性的限制。我们提出了一种优化的研究工具：人类 OA 软骨-滑膜外植体共培养模型 (OA-EXM)，该模型采用供体匹配的下限和上限响应控制结合统计方法来解决变异性问题。多个快速读数允许在对软骨-滑膜相互作用进行分类的同时评估治疗方法。

设计

48 小时人类外植体培养物来自 OA 膝关节置换术。相对于供体匹配的上限超生理促炎细胞因子和下限 OA 软骨或滑膜单独对照，建立了 OA 样软骨-滑膜共培养基线。100 nM 地塞米松治疗在 OA-EXM 双组织环境中验证了可能的“救援效果”。使用阻断和聚类方法分析基因表达、蛋白多糖损失、MMP 活性和可溶性蛋白浓度。

结果

OA-EXM 证明了共培养方法的价值，因为添加 OA 滑膜会增加 OA 软骨蛋白聚糖的损失和MMP1、MMP3、MMP13、CXCL8、CCL2、IL6和PTGS2的表达，但不会达到超生理刺激的程度. 相反，OA 软骨不影响 OA 滑膜的基因表达或 MMP 活性。地塞米松对滑膜（促分解巨噬细胞上调、蛋白酶下调）和软骨（促炎、分解代谢和合成代谢下调）显示双重治疗作用，并降低共培养中的可溶性 CCL2 水平，从而验证 OA-EXM 的效用。

结论

OA-EXM 是晚期 OA 病理学的代表，捕捉软骨和滑膜之间的双重相互作用，并结合统计策略为评估 OA 治疗提供了一种快速、敏感的研究工具。