Analysis of COMP fragments and MMP activities of arthritis

【研究1】马血清和滑液中软骨寡聚基质蛋白（COMP）的夹心ELISA检测体系。本研究制备了抗马软骨COMP的单克隆抗体，测定了其抗原表位，并建立了双抗体夹心ELISA方法。通过新的夹心ELISA以及先前的抑制ELISA测量OA病例的滑液和血清中COMP的浓度，并与正常关节和马中的浓度进行比较。与正常动物的水平相比，使用未标记的2A 11 ×生物素化11 F10 mAb组合的夹心ELISA检测到OA病例血清和SF中的COMP水平显著升高。用双抗体夹心ELISA法测定血清COMP可用于鉴别马OA。[研究2]慢性自身免疫性关节炎对SKG小鼠血液生物标志物水平的影响。6周龄SKG和BALB/c小鼠腹腔注射海带多糖。每周一次，持续17周，对关节炎的严重程度进行评分，并将血液收集在肝素化管中。SKG小鼠在接种海带多糖后3周表现出关节炎评分增加，18周时的组织学分析证实了滑膜炎和软骨和软骨下骨的破坏。SKG小鼠稀释血浆中的MMP-3浓度在接种后8周开始增加，并与关节炎评分增加呈正相关。MMP-3浓度在BALB/c小鼠中没有变化。与BALB/c小鼠相比，SKG小鼠在接种后18周获得的血清中COMP和MMP-3浓度更高。血清中COMP和MMP-3的浓度增加可能是SKG小鼠关节炎的潜在标志物。血浆中MMP-3浓度也可作为SKG小鼠慢性关节炎的指标。

[Study 1] Sandwich ELISA system for cartilage oligomeric matrix protein (COMP) in equine synovial fluid and serum._New monoclonal antibodies (mAbs) were elicited against equine cartilage COMP, their epitopes were determined, and a sandwich ELISA was developed. The concentrations of COMP in synovial fluid and sera from OA cases were measured by the new sandwich ELISA as well as by the previous inhibition ELISA and compared with concentrations in normal joints and horses. Sandwich ELISA with the combination of unlabeled 2A11×biotinylated 11F10 mAbs detected a significant increase in COMP levels in both serum and SF from OA cases compared with levels in normal animals. Measurement of serum COMP with sandwich ELISA could be useful in identifying horses with OA.[Study 2] Effect of chronic autoimmune arthritis on the blood level of biomarkers in SKG mice._Six-week-old SKG and BALB/c mice were intraperitoneally injected with laminarin. Once weekly for 17 weeks, the severity of arthritis was scored and blood was collected in heparinized tubes. SKG mice exhibited increased arthritis scores 3 weeks after inoculation with laminarin, and histological analysis at 18 weeks confirmed synovitis and destruction of cartilage and subchondral bone. MMP-3 concentrations in diluted plasma from SKG mice increased starting at 8 weeks after inoculation and were positively correlated with increased arthritis scores. MMP-3 concentrations did not change in BALB/c mice. COMP and MMP-3 concentrations in serum obtained at 18 weeks after inoculation were higher in SKG mice compared to BALB/c mice. Increased concentrations of both COMP and MMP-3 in serum could be potential markers of arthritis in SKG mice. MMP-3 concentrations in plasma could be also an indicator of chronic arthritis in SKG mice.