Next Generation Gene Therapy for Refractory Pain

项目摘要 慢性疼痛影响美国超过2500万成年人，是残疾的主要原因。目前 可用的疼痛治疗例如阿片类药物通常是无效的 包括呼吸抑制和成瘾。新的疼痛疗法的主要目标是抑制感觉疼痛， 选择性地传递疼痛信号的神经元（伤害感受器），而不影响参与疼痛的其他神经元。 无害的感觉或中枢神经系统。然而，伤害感受器特异性治疗方法 仍处于婴儿期基于病毒的基因疗法在治疗难治性疼痛方面提供了几个有吸引力的优势， 因为病毒可以被改造以递送广泛的分子，可以局部或全身施用， 并且最近已被食品和药物管理局批准用于多种适应症。然而，在这方面， 伤害感受器特异性的病毒工具目前并不存在，这在很大程度上是由于感觉神经元的异常异质性。 这使得识别这些细胞特有的分子特征变得困难。最新进展 在单细胞基因组学中，使我们能够生成一个细胞图谱，描述选择性地 在小鼠和人类伤害感受器中表达。该提案旨在揭示内源性基因调控 介导伤害感受器特异性基因表达模式的元件，并将这些元件工程化为条形码 腺相关病毒文库。为了实现这一点，我们提出了以下具体目标：1）映射 在小鼠和人中的伤害感受器特异性基因调控元件和2）产生伤害感受器特异性 AAV工具包。我们在这项提案中开发的伤害感受器特异性病毒将立即对科学有用。 在野生型小鼠和可能的其他物种中，此外，由于我们将 优先考虑在小鼠和人类伤害感受器之间保守的基因调控元件，我们乐观地认为， 我们在老鼠身上筛选的病毒也会驱动人类伤害感受器特异性基因的表达。接下来的 第二代伤害感受器特异性基因疗法将理想地适用于治疗某些难治性疼痛疾病 因为它们可以通过标准门诊程序局部施用到神经病感觉神经节 并且可以被工程化以驱动离子通道的表达，所述离子通道仅在 化学遗传学（chemogenetics）这种无阿片类药物的方法可能具有重要的转化应用 对于患有难治性慢性疼痛的患者，他们通常没有其他缓解选择。

Project Summary Chronic pain affects over 25 million adults in the United States and is a major cause of disability. Currently available pain treatments such as opioids are often ineffective and associated with unacceptable side effects including respiratory depression and addiction. A major goal for new pain therapeutics is to inhibit the sensory neurons which transmit pain signals (nociceptors) selectively without affecting other neurons involved in innocuous sensation or the central nervous system. However, nociceptor-specific therapeutic approaches remain in their infancy. Viral-based gene therapy offers several attractive advantages in treating refractory pain, as viruses can be engineered to deliver a wide range of molecules, can be administered locally or systemically, and have been recently approved by the Food and Drug Administration for a number of indications. However, nociceptor-specific viral tools do not presently exist in large part due to the extraordinary heterogeneity of sensory neurons that has made it difficult to identify molecular features that are unique to these cells. Recent advances in single-cell genomics have enabled us to generate a cell atlas that describes the genes that are selectively expressed in mouse and human nociceptors. This proposal aims to uncover the endogenous gene regulatory elements that mediate nociceptor-specific gene expression patterns and engineer these elements into barcoded adeno-associated viral libraries. To accomplish this, we propose the following specific aims: 1) Mapping nociceptor-specific gene regulatory elements in mouse and human and 2) Generation of a nociceptor-specific AAV toolkit. The nociceptor-specific viruses we develop in this proposal will be immediately useful to the scientific community for accessing nociceptors in wild-type mice and likely other species. In addition, because we will prioritize gene regulatory elements that are conserved between mouse and human nociceptors, we are optimistic that the viruses we screen in mice will also drive nociceptor-specific gene expression in humans. These next generation nociceptor-specific gene therapies would be ideally suited for treating certain refractory pain disorders because they can be administered locally to neuropathic sensory ganglia through standard outpatient procedures and can be engineered to drive expression of ion channels that silence nociceptor activity only in the presence of a specific drug (chemogenetics). This opioid-free approach could have significant translational applications for patients with refractory chronic pain who often have no other options for relief.