Anatomic, Physiologic and Transcriptomic Mechanisms of Neuropathic Pain in Human DRG

我们发起了MD安德森癌症中心和密歇根大学的合作 德克萨斯州达拉斯的一家使用背根节(DRG)从疼痛表型患者身上移除的组织 在神经外科手术期间。背根节在脊柱稳定时取自胸椎水平。 手术，然后切成三份。三分之一用于免疫组织化学(IHC)或原位检测 杂交(ISH)，三分之一用于培养和电生理，三分之一用于 RNA测序。我们已经开发了一个具有患者疼痛表型的广泛数据集 信息、DRG神经元电生理特性和RNA测序。在许多 我们有来自同一患者的成对DRG，其中患者有一个疼痛 而不是在另一种皮肤病患者中，因此可以进行精确的病例对照分析。我们的电生理学 结果清楚地表明，慢性疼痛与自发性活动(SA)有关 DRG伤害性感受器。这是第一次证明这一点。我们的RNA测序 结果发现DRG中与慢性疼痛和SA相关的转录变化 显示出性二型的迹象。在男性身上，我们发现了明显的免疫渗透迹象 神经免疫相互作用以及一些成员表达的增加 Fos/Jun转录因子家族。在女性身上，我们看到一些G蛋白上调 偶联受体(GPCRs)和其他神经元兴奋性内在变化的迹象。这些 研究结果为不同人群中DRG慢性疼痛的驱动因素提供了独特的见解 对慢性疼痛治疗发展有重要影响的患者，包括 可能需要针对性别的治疗。我们的主要假设是人类背根神经节中的SA 神经元是患者产生疼痛的关键因素，它是由根本驱动的 男性和女性患者发病机制不同。我们将用人类来检验这一假设 DRG样本和电生理学(目标1)和RNA-SEQ(目标2)的组合。在AIM 3中 IHC和ISH以及以初步发现和数据为指导的药理学干预 在该项目期间产生的数据将用于确定新的潜在治疗途径。总而言之， 该项目中的实验将为慢性病的发病机制提供新的基本见解。 疼痛将使治疗性和生物标记物的发现成为可能 对临床护理的直接影响。

We have launched a collaborative effort between MD Anderson Cancer Center and University of Texas at Dallas that uses dorsal root ganglion (DRG) removed from pain phenotyped patients during neurological surgery. DRGs are taken from thoracic levels during a spine stabilization surgery and then cut in thirds. One third is saved for immunohistochemistry (IHC) or in situ hybridization (ISH), one third goes for culturing and electrophysiology, and one third is used for RNA sequencing. We have developed an extensive dataset with patient pain phenotype information, DRG neuron electrophysiological characterization and RNA sequencing. In many cases we have pairs of DRGs from the same patient where the patient had pain in one dermatome and not in another, allowing for precise case-control analysis. Our electrophysiology results clearly demonstrate that chronic pain is associated with spontaneous activity (SA) in DRG nociceptors. This is the first time that this has been demonstrated. Our RNA sequencing results identify transcriptional changes associated with chronic pain and SA in the DRG that show indications of sexual dimorphism. In males we find clear signs of immune infiltration and neuro-immune interactions as well as an increase in expression for some members of the FOS/JUN transcription factor family. In females we see an upregulation of some G-protein coupled receptors (GPCRs) and other signs of intrinsic changes in neuronal excitability. These findings give unique insights into drivers of chronic pain in the DRG in a diverse cohort of patients with important implications for chronic pain therapeutic development, including the potential need for sex-specific treatment. Our overarching hypothesis is that SA in human DRG neurons, which is a critical factor for pain generation in patients, is driven by fundamentally different mechanisms in male and female patients. We will test this hypothesis using human DRG samples and a combination of electrophysiology (Aim 1) and RNA-seq (Aim 2). In Aim 3 IHC and ISH along with pharmacological interventions guided by preliminary findings and data generated during this project will be used to define new potential therapeutic avenues. In sum, the experiments in this project will give fundamental new insight into mechanisms of chronic pain that will enable therapeutic and biomarker discovery with the opportunity for an almost immediate impact on clinical care.