Neural Mechanisms of Gynecological Pain

描述(由申请人提供)：该项目的长期目标是促进对女性慢性盆腔疼痛的神经机制的理解。目前的研究集中在子宫内膜异位症，这是一种由子宫内膜组织外生长定义的疾病。症状包括生育不足和严重的慢性疼痛，包括性交困难(阴道痛觉过敏)、痛经(月经疼痛)和其他盆腔和腹部内脏和肌肉疼痛。这些痛苦是出了名的难以缓解。阻碍开发更好的治疗方法的一个主要因素是，人们对异位生长和疼痛之间的潜在机制知之甚少。存在子宫内膜异位症大鼠模型(Endo)，涉及子宫碎片腹主动脉的自体移植。移植后形成的包囊具有与女性异位生长相似的特征。像女性一样，大鼠生育能力低下，表现出阴道和腹部肌肉的痛觉过敏。拟议的研究将使用这个大鼠模型来测试关于内源性阴道痛敏潜在机制的假说。最近发现，异位生长通过迷走神经和迷走神经在大鼠模型中吸引神经供应，这为研究异位生长与疼痛之间难以捉摸的联系提供了新的方向。目标1中的三项研究将检验这一假设，即内源性阴道高血压症的发生是由于包囊发育中的神经供应活动产生的中枢神经效应所致。研究1-2将比较以下发育时间进程：(I)包囊的神经供应(通过神经元标记物的免疫染色显示)，(Ii)神经供应的活动(通过蛋白质外渗评估)，(Iii)脊髓和脑干处理阴道信息的变化(通过c-Fos和磷酸化N-甲基-D-天冬氨酸受体NR1[pNR1]蛋白的神经元表达评估)，以及(Iv)腹膜细胞因子的含量(使用蛋白质阵列)。通过对阴道伤害性行为的评估，研究3将检验这样的预测：如果假想正确，在神经活动发展之前清除囊肿应该可以防止内源性痛觉过敏的发展。Aim#2中的三项研究将检验这一假设，即维持内源性阴道痛觉过敏需要通过包囊的脊髓、脑干、节段间和/或脊柱上效应的神经供应来维持。通过行为学方法，研究1将验证这一假设的预测，即去神经完全生长的囊肿应该会减少痛觉过敏。研究2将以不同的方式检验这一假说，通过评估完全发育的囊肿失神经如何影响阴道刺激诱导的脊髓和脑干神经元中c-Fos和pNR1的表达。研究3将通过评估脊髓横断如何影响阴道刺激诱导的脊髓和脑干神经元中c-Fos和pNR1的表达，来检验节段间和棘上效应的假说。这些研究的结果有可能提高对导致子宫内膜异位症疼痛的机制的理解，从而导致新的治疗策略。公共卫生相关性：子宫内膜异位症是育龄妇女的常见疾病，在子宫外发现子宫组织异常生长，并伴有严重疼痛，极大地降低生活质量。部分原因是人们对这些异常生长是如何引起这些疼痛知之甚少，众所周知，如果不求助于激素或手术，这些疼痛很难缓解，因为这些激素或手术要么产生无法忍受的副作用，要么无济于事。这项申请中提出的研究将使用经过验证的啮齿动物模型来调查新发现的提供异常生长的神经发芽如何影响中枢神经系统过程以引发疼痛，从而提高知识，从而改进治疗策略。

Description (provided by applicant): The long-term goal of this program is to advance understanding of neural mechanisms of chronic pelvic pain in females. Current studies focus on endometriosis, a disorder defined by extrauteral growths of endometrial tissue. Symptoms include subfertility and severe chronic pains, including dyspareunia (vaginal hyperalgesia), dysmenorrhea (menstrual pain) and other pelvic and abdominal visceral and muscle pains. These pains are notoriously difficult to alleviate. A major factor impeding development of better treatments is that mechanisms underlying the relationship between the ectopic growths and pain are poorly understood. A rat model of endometriosis exists (ENDO) that involves autotransplantion on abdominal arteries of pieces of uterus. The transplants form cysts with characteristics similar to the ectopic growths in women. Like women, the rats are subfertile and exhibit vaginal and abdominal muscle hyperalgesia. The proposed studies will use this rat model to test hypotheses concerning mechanisms underlying ENDO-induced vaginal hyperalgesia. The recent discovery that the ectopic growths attract a nerve supply, via spanchnic and vagus nerves in the rat model, provides a new direction to study the elusive association between the ectopic growths and pain. Three studies in Aim #1 will test the hypothesis that development of ENDO-induced vaginal hyperalge- sia results from central neural effects produced by activity in the cysts' developing nerve supply. Studies 1-2 will compare developmental time courses of: (i) the cysts' nerve supply (visualized by immunostaining with neuronal markers), (ii) activity in the nerve supply (assessed by protein extravasation), (iii) changes in spinal and brainstem processing of vaginal information (assessed by neuronal expression of c-Fos and phosphory- lated N-methyl-D-aspartic acid receptor NR1 [pNR1] proteins), and (iv) peritoneal content of cytokines (using protein arrays). By assessing vaginal nociception behaviorally, Study 3 will test the prediction that, if the hy- pothesis is correct, removing cysts before nerve activity develops should prevent the development of ENDO- induced hyperalgesia. Three studies in Aim #2 will test the hypothesis that maintenance of ENDO-induced vaginal hyperalgesia requires maintenance by the cysts' nerve supply of spinal, brainstem, intersegmental and/or supraspinal effects. With behavioral methods, Study 1 will test the prediction from this hypothesis that denervating fully-grown cysts should reduce the hyperalgesia. Study 2 will test the hypothesis differently, by assessing how denervations of fully-grown cysts affect vaginal-stimulation induced c-Fos and pNR1 express- ion in spinal and brainstem neurons. Study 3 will test hypotheses concerning intersegmental and supraspinal effects by assessing how spinal transections affect vaginal-stimulation-induced c-Fos and pNR1 expression in spinal and brainstem neurons. Results of the studies have the potential for improving understanding of mechanisms that contribute to the pains of endometriosis, thereby leading to new treatment strategies. PUBLIC HEALTH RELEVANCE: Endometriosis is common disorder suffered by women of childbearing age in whom abnormal growths of uterine tissue found outside the uterus are associated with severe pains that greatly reduce quality of life. In part because so little is known about how the abnormal growths give rise to these pains, they are notoriously difficult to alleviate without resorting to hormones or surgery that either produce intolerable side effects or fail to help. Studies proposed in this application will use a validated rodent model to investigate how the newly- discovered nerves that sprout to supply the abnormal growths might influence central nervous system processes to induce the pains, thereby improving knowledge that can lead to improved treatment strategies.