Department of Physics, Imperial College London, London, SW7 2AZ, UK.
Kennedy Institute of Rheumatology, University of Oxford, Oxford, OX3 7FY, UK.
Sci Rep. 2020 Feb 7;10(1):2154. doi: 10.1038/s41598-020-59219-5.
Osteoarthritis (OA) is the most common arthritis and its hallmark is degradation of articular cartilage by proteolytic enzymes leading to loss of joint function. It is challenging to monitor the status of cartilage in vivo and this study explores the use of autofluorescence lifetime (AFL) measurements to provide a label-free optical readout of cartilage degradation that could enable earlier detection and evaluation of potential therapies. We previously reported that treatment of ex vivo porcine cartilage with proteolytic enzymes resulted in decreased AFL. Here we report changes in AFL of ex vivo mouse knee joints, porcine metacarpophalangeal joints, normal human metatarsophalangeal articular tissue and human OA tibial plateau tissues measured with or without treatment using a compact single-point time resolved spectrofluorometer. Our data show that proteolytically damaged areas in porcine metacarpophalangeal joints present a reduced AFL and that inducing aggrecanases in mouse and human joints also significantly reduces AFL. Further, human cartilage from OA patients presents a significantly lower AFL compared to normal human cartilage. Our data suggest that AFL can detect areas of cartilage erosion and may potentially be utilised as a minimally-invasive diagnostic readout for early stage OA in combination with arthroscopy devices.
骨关节炎（OA）是最常见的关节炎，其标志是蛋白水解酶对关节软骨的降解，导致关节功能丧失。监测软骨在体内的状态具有挑战性，本研究探讨了使用自发荧光寿命（AFL）测量来提供软骨降解的无标记光学读数的可能性，这可能使早期检测和评估潜在的治疗方法成为可能。我们之前报道过，用蛋白水解酶处理离体猪软骨会导致 AFL 降低。在这里，我们报告了使用紧凑型单点时间分辨荧光光谱仪测量离体小鼠膝关节、猪掌指关节、正常人类跖趾关节组织和人类 OA 胫骨平台组织的 AFL 变化，无论是否进行治疗。我们的数据表明，猪掌指关节中蛋白水解损伤区域的 AFL 降低，并且在小鼠和人类关节中诱导聚集酶也显著降低 AFL。此外，来自 OA 患者的人类软骨的 AFL 明显低于正常人类软骨。我们的数据表明，AFL 可以检测软骨侵蚀区域，并且可能与关节镜设备结合，作为早期 OA 的微创诊断读数。
