Lawrence J. Ellison Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of California Davis Health.
Lawrence J. Ellison Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of California Davis Health;
J Vis Exp. 2023 Sep 29(199). doi: 10.3791/65249.
Traumatic joint injuries such as anterior cruciate ligament (ACL) rupture or meniscus tears commonly lead to post-traumatic osteoarthritis (PTOA) within 10-20 years following injury. Understanding the early biological processes initiated by joint injuries (e.g., inflammation, matrix metalloproteinases (MMPs), cathepsin proteases, bone resorption) is crucial for understanding the etiology of PTOA. However, there are few options for in vivo measurement of these biological processes, and the early biological responses may be confounded if invasive surgical techniques or injections are used to initiate OA. In our studies of PTOA, we have used commercially available near-infrared protease activatable probes combined with fluorescence reflectance imaging (FRI) to quantify protease activity in vivo following non-invasive compression-induced ACL injury in mice. This non-invasive ACL injury method closely recapitulates clinically relevant injury conditions and is completely aseptic since it does not involve disrupting the skin or the joint capsule. The combination of these injury and imaging methods allows us to study the time course of protease activity at multiple time points following a traumatic joint injury.
创伤性关节损伤，如前交叉韧带（ACL）撕裂或半月板撕裂，通常会在受伤后 10-20 年内导致创伤后骨关节炎（PTOA）。了解关节损伤引发的早期生物学过程（如炎症、基质金属蛋白酶（MMPs）、组织蛋白酶蛋白酶、骨吸收）对于理解 PTOA 的病因至关重要。然而，能够对这些生物学过程进行体内测量的方法很少，如果使用侵入性手术技术或注射来引发 OA，则可能会混淆早期的生物学反应。在我们对 PTOA 的研究中，我们使用了市售的近红外蛋白酶激活探针，结合荧光反射成像（FRI），在非侵入性压缩诱导的 ACL 损伤后，在体内定量蛋白酶的活性。这种非侵入性 ACL 损伤方法非常接近临床相关的损伤情况，因为它完全是无菌的，不涉及破坏皮肤或关节囊。这些损伤和成像方法的结合使我们能够在创伤性关节损伤后多个时间点研究蛋白酶活性的时间进程。
