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

我们已经启动了MD安德森癌症中心和密歇根大学之间的合作努力， 德克萨斯州达拉斯的一项研究，该研究使用从疼痛表型患者中取出的背根神经节（DRG） 在神经外科手术中。在脊柱稳定期间，从胸椎水平采集DRG 手术，然后切成三分之一。三分之一保存用于免疫组织化学（IHC）或原位 杂交（ISH），三分之一用于培养和电生理学，三分之一用于 RNA测序。我们已经开发了一个广泛的患者疼痛表型数据集 信息，DRG神经元电生理表征和RNA测序。在许多 在病例中，我们有来自同一患者的成对DRG，其中一个患者疼痛 而不是在另一个，允许精确的病例对照分析。我们的电生理 结果清楚地表明，慢性疼痛与自发活动（SA）有关， 背根神经节伤害感受器。这是第一次证明这一点。我们的RNA测序 结果确定了与背根神经节中慢性疼痛和SA相关的转录变化， 显示出两性异形的迹象在男性中，我们发现了免疫渗透的明显迹象， 神经免疫相互作用以及一些成员的表达增加， FOS/JUN转录因子家族。在女性中，我们看到一些G蛋白的上调 偶联受体（GPCR）和神经元兴奋性内在变化的其他迹象。这些 研究结果为DRG中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具有重要意义的患者，包括 可能需要性别特异性治疗。我们的总体假设是，人DRG中的SA 神经元是患者疼痛产生的关键因素， 男性和女性患者的不同机制。我们将使用人类来测试这一假设。 DRG样品以及电生理学（目标1）和RNA-seq（目标2）的组合。在目标3 IHC和ISH沿着以初步发现和数据为指导的药物干预 在这个项目中产生的将被用来定义新的潜在的治疗途径。总之， 该项目的实验将为慢性炎症的机制提供基本的新见解。 疼痛，这将使治疗和生物标志物的发现， 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.