Current drug discovery efforts focus on identifying lead compounds acting on a molecular target associated with an established pathological state. Concerted molecular changes that occur in specific cell types during disease progression have generally not been identified. Here, we used constellation pharmacology to investigate rat dorsal root ganglion neurons using two models of peripheral nerve injury: chronic constriction injury (CCI) and spinal nerve ligation (SNL). In these well-established models of neuropathic pain, we show that the onset of chronic pain is accompanied by a dramatic, previously unreported increase in the number of bradykinin-responsive neurons, with larger increases observed after SNL relative to CCI. To define the neurons with altered expression, we charted the temporal course of molecular changes following 1, 3, 6, and 14 d after SNL injury and demonstrated that specific molecular changes have different time courses during the progression to a pain state. In particular, ATP receptors up-regulated on day 1 postinjury, whereas the increase in bradykinin receptors was gradual after day 3 postinjury. We specifically tracked changes in two subsets of neurons: peptidergic and nonpeptidergic nociceptors. Significant increases occurred in ATP responses in nAChR-expressing isolectin B4+ nonpeptidergic neurons 1 d postinjury, whereas peptidergic neurons did not display any significant change. We propose that remodeling of ion channels and receptors occurs in a concerted and cell-specific manner, resulting in the appearance of bradykinin-responsive neuronal subclasses that are relevant to chronic pain.

当前的药物发现工作集中于鉴定作用于与既定病理状态相关的分子靶标的先导化合物。通常还没有确定在疾病进展过程中特定细胞类型中发生的协同分子变化。在这里，我们使用星座药理学，使用两种周围神经损伤模型研究大鼠背根神经节神经元：慢性收缩损伤（CCI）和脊髓神经结扎（SNL）。在这些公认的神经性疼痛模型中，我们显示，慢性疼痛的发作伴随着缓激肽反应性神经元数量的急剧增加，以前未报道，而SNL后相对于CCI观察到的增加更大。为了定义表达改变的神经元，我们绘制了1、3、6之后分子变化的时间过程图 和SNL损伤后14 d，证明特定的分子变化在发展为疼痛状态期间具有不同的时程。特别是，ATP受体在损伤后第1天上调，而缓激肽受体的增加在损伤后第3天逐渐升高。我们专门跟踪了神经元的两个子集的变化：肽能和非肽能感受器。损伤后1 d，表达nAChR的isolectin B4 +非肽能神经元的ATP反应显着增加，而肽能神经元未显示任何显着变化。我们提出离子通道和受体的重塑以协同和细胞特异性的方式发生，导致出现与慢性疼痛有关的缓激肽反应性神经元亚类。