Screening antibiotics using NIR fluorescence imaging for osteoarthritis treatment

摘要 骨关节炎（OA）是美国残疾的主要原因;但尽管其患病率很高， 治疗这种疾病。OA是一种以关节软骨破坏为特征的全关节疾病， 骨赘形成以及滑膜炎。它与局部炎症有关， 软骨降解酶如基质金属蛋白酶（MMPs）的表达和细胞凋亡 介质如半胱天冬酶，导致基质降解和细胞死亡。最近，某些大环内酯类 通常用于治疗细菌感染的抗生素，例如红霉素和阿奇霉素， 据报道具有独立于抗生素功能的抗炎功能。但无论 这些抗生素对关节软骨保护和OA进展有任何作用尚不清楚。有效地 在几种剂量方案中评估多种大环内酯类药物，需要一种灵敏的筛选方法， 缩小目标范围以便进行更详细的组织学确认 我们的长期目标是研究和开发治疗OA的新策略。这项研究的目的是 使用近红外光谱技术筛选大环内酯类抗生素抑制OA关节破坏的潜力 荧光（NIRF）成像技术。这是基于我们最近的研究表明， 红霉素的软骨保护作用。此外，通过使用MMP-激活的荧光探针，我们发现， NIRF信号在小鼠关节OA发展过程中表现出逐渐的变化， 从组织学分析中总是显而易见的。这表明NIRF成像是一种敏感的方法， 在OA的各个阶段检测关节的变化，否则可能会被忽视。同样的动物 可以快速和重复成像，NIRF成像也是有效的，并允许关节的轨迹 在同一动物中进行评价。因此，我们假设其他成员的 大环内酯类抗生素也可以调节OA进展，如通过灵敏的NIRF所确定的 成像技术 为了验证这一假设，我们将评估大环内酯类抗生素对小鼠关节退行性变的影响。 实验OA在体内和人关节软骨细胞在体外使用NIRF成像。除了 通常使用的大环内酯类抗生素，我们还将研究这些大环内酯类的衍生物， 抗生素功能。我们的跨学科团队由具有丰富经验的研究人员组成， 病理学和成像，协同我们对这项新研究的努力。如果成功，这项工作将开启一个 探索OA治疗选择的新方向，利用已批准用于其他适应症的药物。它 还将进一步开发灵敏的代谢成像工具，用于OA治疗剂的体内筛选， 以深刻和互补的方式增强传统的评价方法。

Abstract Osteoarthritis (OA) is a leading cause of disability in the US; but despite its prevalence, there is no optimal treatment for this disease. OA is a whole joint disease characterized by articular cartilage destruction, osteophyte formation as well as synovitis. It is associated with local inflammation, which promotes the expression of cartilage-degrading enzymes such as matrix metalloproteinases (MMPs) and apoptosis mediators such as caspases, leading to matrix degradation and cell death. Recently, certain macrolide antibiotics that are typically used to treat bacterial infection, such as erythromycin and azithromycin, have been reported to have anti-inflammatory functions that are independent of the antibiotic function. However, whether these antibiotics have any effects on joint cartilage protection and OA progression is not known. To efficiently evaluate multiple macrolides across several dosage schemes, a sensitive screening method is necessary to narrow down targets for further detailed histological confirmation. Our long-term goal is to investigate and develop new strategies in treating OA. The goal of this research is to screen macrolide antibiotics for the potential to inhibit joint destruction in OA using the Near Infrared Fluorescence (NIRF) imaging technology. This is based on our recent studies demonstrating a chondroprotective role for erythromycin. In addition, by using an MMP-activatable fluorescent probe, we found NIRF signals exhibit gradual changes over the course of OA development in the murine joint that are not always evident from histological analysis. This demonstrates that NIRF imaging is a sensitive approach to detect changes in the joint in various stages of OA that may otherwise go unnoticed. As the same live animals can be imaged quickly and repeatedly, NIRF imaging is also efficient and allows the trajectory of joint destruction in the same animal to be evaluated. Therefore, we hypothesize that other members of the macrolide class of antibiotics can also regulate OA progression as identified through the sensitive NIRF imaging technology. To test this hypothesis, we will evaluate the effect of macrolide antibiotics on joint degeneration in murine experimental OA in vivo and human articular chondrocytes in vitro using NIRF imaging. In addition to commonly used macrolide antibiotics, we will also investigate a derivative of these macrolides that is devoid of its antibiotic function. Our interdisciplinary team consists of investigators with extensive experience in joint pathology and imaging, synergizing our efforts toward this novel research. If successful, this work will open a new direction to explore OA treatment options, capitalizing on drugs already approved for other indications. It will also further develop the sensitive metabolic imaging tool towards in vivo screening of OA therapeutics, thus augmenting traditional evaluation approaches in a profound and complementary way.