Lim N H, Meinjohanns E, Meldal M, Bou-Gharios G, Nagase H
Arthritis Research UK Centre for Osteoarthritis Pathogenesis, Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford University, UK.
Carlsberg Laboratory, Denmark.
Osteoarthritis Cartilage. 2014 Jun;22(6):862-8. doi: 10.1016/j.joca.2014.04.006. Epub 2014 Apr 18.
To detect and determine disease severity of osteoarthritis (OA) using a probe activated by matrix metalloproteinase-13 (MMP-13) in vivo in the murine destabilised medial meniscus (DMM) surgical model of OA.
We have previously described MMP12ap and MMP13ap, internally quenched fluorescent peptide substrate probes that are activated respectively by MMP-12 and MMP-13. Here we used these probes to follow enzyme activity in vivo in mice knees 4, 6 and 8 weeks following DMM surgery. After in vivo optical imaging, disease severity was determined through traditional histological analysis. The amount of probe activation was analysed for discrimination between DMM, contralateral and sham operated knees, as well as for congruence between activity and histological damage.
There was no specific activation of MMP12ap at the time points observed between sham operated and DMM operated, or their respective contralateral joints. The activation of the MMP13ap in the DMM model was highest 6 weeks after surgery, but was only specific compared against sham surgery 8 weeks after surgery (1.5-fold increase). The activation of MMP13ap correlated with histological damage 6 and 8 weeks after surgery, with correlations of 0.484 (P = 0.0032) and 0.478 respectively (P = 0.0049). This correlation dropped to 0.218 (P = 0.011) if all data were considered.
The current MMP-13 activity probe is suitable for the discrimination between DMM and sham or contralateral knees 8 weeks after surgery, when cartilage loss is typified by the appearance of small fissures up to the tidemark, but not earlier. This activity correlates with the histological damage observed.
在骨关节炎（OA）的小鼠内侧半月板不稳定（DMM）手术模型中，使用基质金属蛋白酶-13（MMP-13）激活的探针在体内检测并确定骨关节炎的疾病严重程度。
我们之前描述了MMP12ap和MMP13ap，这两种内部淬灭的荧光肽底物探针分别由MMP-12和MMP-13激活。在此，我们使用这些探针追踪DMM手术后4周、6周和8周小鼠膝关节内的酶活性。在进行体内光学成像后，通过传统组织学分析确定疾病严重程度。分析探针激活量以区分DMM、对侧和假手术膝关节，以及活性与组织学损伤之间的一致性。
在假手术和DMM手术组及其各自对侧关节之间观察的时间点，MMP12ap没有特异性激活。DMM模型中MMP13ap的激活在手术后6周最高，但仅在手术后8周与假手术相比具有特异性（增加1.5倍）。MMP13ap的激活与手术后6周和8周的组织学损伤相关，相关性分别为0.484（P = 0.0032）和0.478（P = 0.0049）。如果考虑所有数据，这种相关性降至0.218（P = 0.011）。
当前的MMP-13活性探针适用于在手术后8周区分DMM与假手术或对侧膝关节，此时软骨损失表现为直至潮线的小裂缝出现，但更早时则不适用。这种活性与观察到的组织学损伤相关。
