Role of TNFalpha in discogenic pain progression and as a treatment target

摘要 背痛是导致全球残疾的主要原因，而腰椎间盘(IVD)疾病在特定和 非特定的疼痛和残疾。虽然脊柱手术可以有效地解决疼痛的特定原因，但导致椎间变性的 疼痛，或轴性背痛，以IVD变性为最常见的诊断，是非特异性的，缺乏有效性 治疗策略。椎间盘源性疼痛的原因很难确定，因为放射学上的IVD变性是 在有症状的患者和无疼痛的对照组中都很常见，治疗策略也是非特异性的。 因此，迫切需要有针对性的和新的干预措施来治疗椎间盘源性疼痛，但目前的科学研究是有限的。 由于缺乏关于IVD损伤如何发展为神经炎性病理以及如何发展为神经炎性病理的基本信息 这是可以调节的。事实上，令人惊讶的是，关于静脉畸形和背根节(DRGs)是如何相互作用的，人们知之甚少 对IVD损伤和变性的反应，尽管涉及肿瘤坏死因子α的慢性炎症 肿瘤坏死因子α起着关键作用。此外，几乎没有关于间盘源性疼痛的性别差异的研究，尽管 已知的疼痛传递的性别差异。这个项目解决了IVD损伤如何发展为慢性 间盘性疼痛涉及IVD变性和DRG神经炎症，以及如何调节这一点。我们的 前提是血管内皮细胞损伤通过肿瘤坏死因子α调节的血管内皮细胞变性进展为慢性间盘源性疼痛，并且 DRG的敏化和重塑；长期的间盘性疼痛的治疗是难治性的，简单的 治疗，需要针对IVD和神经病理的干预措施。我们开发了一个强大的 描述了活体大鼠的间盘源性疼痛模型和新的跨学科合作。试点结果 表明肿瘤坏死因子α是血管内皮细胞变性和疼痛发生的重要因素，而肿瘤坏死因子α受体 1(TNFR1)和TNFR2在IVD和DRG之间的炎性串扰中扮演着不同的角色，需要进一步 了解病理生理学和确定治疗方法的调查。目标1确定肿瘤坏死因子α的作用及其 受体在从IVD损伤到慢性间盘源性疼痛的进展中的作用 人IVD细胞。AIM 2使用单细胞RNAseq(ScRNAseq)来鉴定IVD和DRG细胞和分子 肿瘤坏死因子α介导并受新药阿特林影响的长期间盘性疼痛的重要通路 这阻止了与TNFR1相关的分解代谢，促进了与TNFR2相关的合成代谢。AIM 3治疗慢性颈椎病 使用阿特林、度洛西汀(一种对神经病理性疼痛有效的抗抑郁药)和联合治疗的疼痛 以解决IVD变性和神经病理学问题。AIMS使用大鼠体内模型和人类体外细胞 培养模型系统，包括行为、基因和蛋白质测量，以及下一代测序。 该项目的成果包括确定肿瘤坏死因子α及其受体在血管内皮细胞瘤发生和发展中的作用。 识别肿瘤坏死因子α调节的细胞和分子通路在IVD-DRG的串音中的关键作用 在长期间盘性疼痛中；开发慢性间盘性疼痛的新治疗策略；以及确定 潜在的性别差异在间盘性疼痛的病理生理和治疗。

Summary Back pain is a leading cause of global disability and intervertebral disc (IVD) disorders play a role in specific and non-specific pain and disability. While spinal surgery can effectively address specific causes of pain, discogenic pain, or axial back pain with IVD degeneration as the most common diagnosis, is non-specific and lacks effective treatment strategies. Causes of discogenic pain are hard to identify since radiographic IVD degeneration is common in both symptomatic patients and pain-free controls, and treatment strategies are also non-specific. Hence, a critical need exists for targeted and novel interventions for discogenic pain, yet current science is limited by a lack of fundamental information on how IVD injury progresses to neuroinflammatory pathologies, and how this can be modulated. In fact, surprisingly little is known about how IVDs and dorsal root ganglia (DRGs) interact in response to IVD injury and degeneration, although chronic inflammation involving tumor necrosis factor alpha (TNFα) plays a key role. Furthermore, almost no studies on sex differences in discogenic pain exist despite known sex differences in pain transmission. This project addresses how IVD injury progresses to chronic discogenic pain involving IVD degeneration and DRG neuroinflammation, and how this can be modulated. Our premise is that IVD injuries progress to chronic discogenic pain via TNFα-modulated IVD degeneration, and DRG sensitization and remodeling; and that the treatment of long-term discogenic pain is refractory with simple treatments and requires interventions that target both IVD and neural pathologies. We developed a robustly characterized in vivo rat discogenic pain model and novel interdisciplinary collaborations. Pilot results demonstrate that TNFα is an essential factor in the onset of IVD degeneration and pain, and that TNFα receptor 1 (TNFR1) and TNFR2 have distinct roles in the inflammatory cross-talk between IVDs and DRGs needing further investigation to understand pathophysiology and identify treatments. Aim 1 determines the role of TNFα and its receptors in the progression from IVD injury to chronic discogenic pain using a rat discogenic pain model and human IVD cells. Aim 2 uses single cell RNAseq (scRNAseq) to identify IVD and DRG cells and molecular pathways important in long-term discogenic pain that are TNFα-mediated and affected by Atsttrin, a novel drug that blocks TNFR1-related catabolism and promotes TNFR2-related anabolism. Aim 3 treats chronic discogenic pain using Atsttrin, Duloxetine (an anti-depressant with efficacy for neuropathic pain), and combined treatments to address both IVD degeneration and neuropathology. Aims use rat in vivo models and human in vitro cell culture model systems with behavioral, gene and protein measurements, as well as next generation sequencing. Outcomes of this project include determining the role of TNFα and its receptors in onset and progression of discogenic pain; identifying TNFα-modulated cells and molecular pathways critical in the IVD-DRG of cross-talk in long-term discogenic pain; developing novel treatment strategies for chronic discogenic pain; and identifying potential sex differences in discogenic pain pathophysiology and treatment.