Central sensitization in osteoarthritis pain: Validation of rodent models, development of biomarkers for diagnosis and anti-inflammatory inhibitors for treatment.

骨关节炎（OA）是关节炎的最常见形式，也是老年人疼痛和残疾的主要原因。我们假设，先天免疫系统激活，最好的记录在病原体的反应，可能在诱导炎症介质和特定的细胞浸润在OA中看到的作用。我们先前将免疫系统激活与致敏过程联系起来，认为这是自发出现的关节炎疼痛（即休息时）、痛觉过敏（对伤害性刺激的疼痛反应增加）和异常性疼痛（对正常非疼痛刺激的疼痛反应）的基础。我们在实验大鼠和狗以及自然猫和狗的OA模型中证明了这一点。致敏作用还促进传出神经元过程，神经系统通过传出神经元过程影响炎症/免疫过程。这可能导致经常观察到的OA受试者临床疼痛严重程度与关节变化程度之间的差异。这些观察结果促使研究OA中枢疼痛感知机制的工作。通过研究不同物种的慢性疼痛综合征，我们已经验证了一种中枢致敏评估方法，包括特定的神经蛋白质组定量，神经力学测试，神经生理学致敏测试（机械时间总和）和功能性神经影像学。我们将应用这些来确定最适合研究致敏的实验大鼠OA模型，然后使用转基因小鼠模型确认炎症/免疫信号通路的作用。最后，为了研究促炎细胞因子在OA结构和疼痛发病机制中的中心作用，我们将使用各种药理学方法阻断白细胞介素-1受体结合。我们的假设是，由原始负变构调节剂产生的抑制将对关节改变和神经元致敏产生最大的影响，沿着最少的副作用。这将为早期OA的创新抗炎药理学方法开辟领域。

Osteoarthritis (OA) is the most common form of arthritis and a major cause of pain and disability in older adults. We hypothesized that innate immune system activation, best documented in response to pathogens, likely plays a role in the induction of inflammatory mediators and the specific cellular infiltrates seen in OA. We previously linked immune system activation to the processes of sensitization, thought to be the basis for arthritic pain that appears spontaneously (that is, at rest), and hyperalgesia (increased pain responses to noxious stimulation) and allodynia (pain in response to normally non-painful stimulation). We demonstrated this in both experimental rat and dog, as well as natural cat and dog, OA models. Sensitization also facilitates the efferent neuronal processes through which the nervous system influences the inflammatory/immune process. This could contribute to the frequently observed disparity between clinical pain severity and the extent of joint changes in subjects with OA. Such observations have prompted work to investigate the mechanisms of central pain perception in OA. By studying chronic pain syndromes in different species, we have validated a method of central sensitization assessment that includes specific neuroproteome quantification, neuromechanical testing, neurophysiological sensitization testing (mechanical temporal summation) and functional neuroimaging. We will apply these to the determination of the experimental rat OA model best suited to studying sensitization, before confirming the role of inflammatory/immune signalling pathways using genetically modified mouse models. Finally, to study the central role of pro-inflammatory cytokines in OA structure and pain pathogenesis, we will block interleukin-1 receptor binding using various pharmacological approaches. Our hypothesis is that the inhibition produced by an original negative allosteric modulator will have the greatest effects on joint alterations and neuronal sensitization, along with the fewest side effects. This will open the field for an innovative anti-inflammatory pharmacological approach to early OA.