TenBroek Erica M, Yunker Laurie, Nies Mae Foster, Bendele Alison M
Medtronic Inc., 710 Medtronic Parkway, Minneapolis, MN, 55432, USA.
Bolder BioPATH, Inc., 5541 Central Avenue, Suite 160, Boulder, CO, 80301, USA.
Arthritis Res Ther. 2016 Jan 21;18:24. doi: 10.1186/s13075-016-0921-5.
As an initial step in the development of a local therapeutic to treat osteoarthritis (OA), a number of agents were tested for their ability to block activation of inflammation through nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), subchondral bone changes through receptor activator of nuclear factor κB ligand (RANKL)-mediated osteoclastogenesis, and proteolytic degradation through matrix metalloproteinase (MMP)-13 activity. Candidates with low toxicity and predicted efficacy were further examined using either of two widely accepted models of OA joint degeneration in the rat: the monoiodoacetic acid (MIA) model or the medial meniscal tear/medial collateral ligament tear (MMT/MCLT) model.
Potential therapeutics were assessed for their effects on the activation of nuclear factor (NF)-κB, RANKL-mediated osteoclastogenesis, and MMP-13 activity in vitro using previously established assays. Toxicity was measured using HeLa cells, a synovial cell line, or primary human chondrocytes. Drugs predicted to perform well in vivo were tested either systemically or via intraarticular injection in the MIA or the MMT/MCLT model of OA. Pain behavior was measured by mechanical hyperalgesia using the digital Randall-Selitto test (dRS) or by incapacitance with weight bearing (WB). Joint degeneration was evaluated using micro computed tomography and a comprehensive semiquantitative scoring of cartilage, subchondral bone, and synovial histopathology.
Several agents were effective both in vitro and in vivo. With regard to pain behavior, systemically delivered clonidine was superior in treating MIA-induced changes in WB or dRS, while systemic clonidine, curcumin, tacrolimus, and fluocinolone were all somewhat effective in modifying MMT/MCLT-induced changes in WB. Systemic tacrolimus was the most effective in slowing disease progression as measured by histopathology in the MMT/MCLT model.
All of the agents that demonstrated highest benefit in vivo, excepting clonidine, were found to inhibit MMP-13, NF-κB, and bone matrix remodeling in vitro. The MIA and MMT/MCLT models of OA, previously shown to possess inflammatory characteristics and to display associated pain behavior, were affected to different degrees by the same drugs. Although no therapeutic was remarkable across all measures, the several which showed the most promise in either model merit continued study with alternative dosing and therapeutic strategies.
作为开发用于治疗骨关节炎（OA）的局部治疗药物的第一步，测试了多种药物阻断炎症激活（通过活化B细胞核因子κ轻链增强子（NF-κB））、软骨下骨改变（通过核因子κB受体活化因子配体（RANKL）介导的破骨细胞生成）以及蛋白水解降解（通过基质金属蛋白酶（MMP）-13活性）的能力。使用大鼠OA关节退变的两种广泛接受的模型之一，即单碘乙酸（MIA）模型或内侧半月板撕裂/内侧副韧带撕裂（MMT/MCLT）模型，对低毒性且预测有疗效的候选药物进行了进一步研究。
使用先前建立的检测方法，在体外评估潜在治疗药物对核因子（NF）-κB激活、RANKL介导的破骨细胞生成以及MMP-13活性的影响。使用HeLa细胞、滑膜细胞系或原代人软骨细胞测量毒性。预测在体内表现良好的药物在OA的MIA或MMT/MCLT模型中进行全身给药或关节内注射测试。使用数字Randall-Selitto试验（dRS）通过机械性痛觉过敏或通过负重（WB）失能来测量疼痛行为。使用微型计算机断层扫描以及对软骨、软骨下骨和滑膜组织病理学进行全面的半定量评分来评估关节退变。
几种药物在体外和体内均有效。关于疼痛行为，全身给药的可乐定在治疗MIA诱导的WB或dRS变化方面更具优势，而全身给药的可乐定、姜黄素、他克莫司和氟轻松在改善MMT/MCLT诱导的WB变化方面均有一定效果。在MMT/MCLT模型中，通过组织病理学测量，全身给药的他克莫司在减缓疾病进展方面最有效。
除可乐定外，所有在体内显示出最大益处的药物在体外均被发现可抑制MMP-13、NF-κB和骨基质重塑。OA的MIA和MMT/MCLT模型先前已显示具有炎症特征并表现出相关的疼痛行为，受到相同药物的不同程度影响。尽管没有一种治疗方法在所有指标上都表现出色，但在任一模型中显示出最有前景的几种药物值得继续研究替代给药方式和治疗策略。
