Mechanism of intrathecal Contulakin-G induced analgesia without motor block

有效治疗高冲击性疼痛患者是国家疼痛战略的主要目标之一。尽管利用脊髓疼痛处理机制的鞘内植入式给药系统在大多数难治性疼痛患者中非常有效，但其使用受到限制，主要是因为其使用的药物（阿片类药物、齐iconotide、局部麻醉剂）相关的副作用，如耐受性、精神病和运动阻滞。利用脊柱疼痛处理的新型镇痛药在人体中安全使用，并且具有最小的运动阻滞和耐受性，在治疗高冲击性疼痛方面可能是革命性的。Contulakin-G （CGX）是一种源自蜗牛毒液的肽，与哺乳动物神经紧张素具有同源性，已被证明在人类中是安全的，一项小型的1a期中导研究证实了它的镇痛作用。先前发表的研究和我们的初步数据表明，鞘内CGX对各种顽固性疼痛具有最小耐受性和运动阻滞的镇痛作用。然而，CGX引发的无运动阻滞镇痛的机制和受体信号通路尚不清楚。我们的初步数据表明，CGX激活神经紧张素受体2 (NT2)，抑制r型电压门控钙通道（VGCC）。有趣的是，虽然NT2存在于感觉神经元和运动神经元中，但r型VGCC表达在疼痛神经元和一些运动神经元中更具选择性。在这个项目中，我们提出验证一个创新的假设，即脊髓CGX产生无运动阻滞的镇痛是继发于CGX激活神经紧张素受体2 (NT2)，导致r型VGCC在感觉神经元而不是运动神经元中受到抑制。我们建议在体外（SA1）和体内（SA2）研究中心假设。我们结合尖端的科学工具，如CRISPR-Cas9编辑和接近连接试验，以及高度验证的体外和体内试验来解决这些问题。这些建议的研究验证了一个具有高度翻译意义的新假设，它们也为受过高度训练的介入性疼痛医生和药理学家提供了职业发展机制，这些医生和药理学家由具有强大成功学员谱系的成功疼痛科学家指导。这些研究的数据不仅将构成后续R01申请的基础，并允许申请人成为独立资助的临床医生科学家，而且有可能在迫切需要缓解的患者群体中导致非阿片类药物的临床进展。

Effective treatment of high-impact pain patients is one the major stated goals of the National Pain Strategy. Although implanted intrathecal drug delivery system that takes advantage of spinal pain processing mechanisms is highly effective in most intractable pain patients, their use is limited primarily because of the side effects such as tolerance, psychosis and motor block associated with drugs used in them (opioids, ziconotide, local anesthetics). Novel analgesics that take advantage of spinal pain processing, are safe to use in humans and have minimal motor block and tolerance can be revolutionary in the management of high-impact pain. Contulakin-G (CGX) is a snail venom derived peptide that has homology with mammalian neurotensin has been shown to be safe in humans and a small, pilot Phase1A study demonstrated its analgesic effect. Prior published studies and our preliminary data demonstrate that intrathecal CGX is analgesic in various intractable pain conditions with minimal tolerance and motor block. However, the mechanism behind the analgesia without motor block and the receptor signaling pathway elicited by CGX is not known. Our preliminary data suggest that CGX activates neurotensin receptor 2 (NT2) to inhibit the R-type voltage gated calcium channels (VGCC). Interestingly, although NT2 is present in both sensory and motor neurons, R-type VGCC expression is more selective in pain neurons and possibly some motor neurons. In this project, we propose to test an innovative hypothesis that spinal CGX produces analgesia without motor block is secondary to CGX activation of neurotensin receptor 2 (NT2) leading to inhibition of R-type VGCC in sensory but not motor neurons. We propose to study the central hypothesis both in vitro (SA1) and in vivo (SA2). We incorporate cutting edge scientific tools such as CRISPR-Cas9 editing and proximity ligation assay coupled with highly validated in vitro and in vivo assays to address these questions. The proposed studies test a novel hypothesis with high translational significance and they also serve as a career development mechanism for a highly trained, interventional pain physician and pharmacologist who is mentored by accomplished pain scientists with a strong pedigree of successful mentees. Data from these studies will not only form the basis of a subsequent R01 application and allow the applicant to be an independently funded clinician scientist but have the potential to lead to clinical advancement of a nonopioid drug in a patient population that desperately needs relief.