Pain and Endometriosis: Effects on Ectopic Cyst Innervation and Axons

描述(由申请人提供)：患有子宫内膜异位症的女性通常会有很大的疼痛。现代研究表明，子宫内膜囊肿的新生神经支配是疼痛的主要来源。然而，神经纤维的存在并不一定说明它们的功能，也不能确定它们是否或在哪些情况下是活跃的。目前还没有关于子宫内膜病变对神经或轴突的影响的功能特征的研究。我们的实验室一直专注于炎症对轴突的影响。我们已经证明，神经炎症诱导了伤害性感受器轴突的异位机械敏感性，而伤害性感受器轴突通常不敏感。我们的数据还表明，神经炎症诱导发炎部位和/或细胞体的持续活动，交感神经元活动在神经炎症期间减少。最近，我们改进了大鼠子宫内膜异位症的模型，使其牵涉到坐骨神经。这种模型非常类似于大鼠子宫内膜异位症模型，即将一段子宫移植到腹膜内。在初步数据中，子宫部分被移植到坐骨神经上。提出了三种互补的电生理学方法来确定子宫、子宫内膜和子宫肌层对坐骨神经的影响特征。首先，将确定贯穿传导性轴突的比例。然后，在一些实验中，将从背根进行梳理纤维记录，在其他实验中，将从周围神经的远端进行梳理。这种方法的结合提供了一个优势，即可以研究穿过囊肿的感觉轴突和交感轴突，以及那些支配囊肿的轴突。我们将确定轴突是否靠近囊肿或直接支配囊肿会产生持续的活动和/或机械敏感性。记录将在手术后3个月，囊变稳定后，并将结果与子宫肌层或脂肪移植，以及未手术的神经进行比较。由于初步结果显示神经内存在免疫细胞，我们将确定子宫内膜异位症的病变是否损害轴突。重要的是，我们将不仅使用全层子宫，还将使用分离的子宫内膜和子宫肌层，并评估这些特定组织形成囊肿的生存能力。利用免疫组织学方法，我们将确定神经-子宫复合体中性粒细胞和巨噬细胞的侵袭程度。我们还将使用忍者宁和氟玉石来确定轴突是否受损，评估轴突和背根神经节细胞的存在。这些研究将确定子宫内膜囊肿异位神经支配的功能和重要性，以及病变对传导性轴突的影响。本研究的结果将影响对子宫内膜异位症疼痛的认识，并为进一步研究子宫内膜异位症的疼痛机制奠定基础。 公共卫生相关性：在这些研究中，我们计划发展我们最近开发的坐骨神经子宫内膜异位症模型，以对子宫内膜异位症相关疼痛的病因进行新的探讨。这项研究将提供的信息将有助于提高对子宫内膜异位症症状的诊断意识和机制理解，从而提高治疗方法。作为这项研究的结果，在消融性腹腔镜技术中考虑和特殊检查盆腔内的神经可能成为子宫内膜异位症妇女的一个重要的附加诊断程序。

DESCRIPTION (provided by applicant): Women with endometriosis often have significant pain. Modern studies have implicated the neo-innervation of endometrial cysts as a primary source of this pain. However, the presence of nerve fibers does not necessarily specify their function and cannot determine whether, or in which situations, they are active. There has been no investigation to functionally characterize the effect of endometrial lesions on nerves or on axons. Our laboratory has focused on the effects of inflammation on axons. We have shown that nerve inflammation induces ectopic mechanical sensitivity of nociceptor axons, which are not normally sensitive. Our data also indicate that nerve inflammation induces ongoing activity that arises from both the inflamed site and / or the cell body, and that sympathetic neuronal activity is decreased during nerve inflammation. Recently we adapted the model of rat endometriosis to involve the sciatic nerve. This model is very similar to the rat endometriosis model where a section of uterus is transplanted to a intraperitoneal site. In preliminary data, a uterine section was transplanted to the sciatic nerve. Three complimentary electrophysiological methods are proposed to determine the characteristics of the effect of uterus, endometrium, and myometrium on the sciatic nerve. First, the proportion of through-conducting axons will be determined. Then, teased fiber recordings will be made from the dorsal roots in some experiments and from the distal end of peripheral nerves in other experiments. This combination of methods offers the advantage that sensory and sympathetic axons that pass through the cyst, as well as those innervating the cyst, can be studied. We will determine if the axons passing in close proximity to the cyst or directly innervating the cyst develop ongoing activity and / or mechanical sensitivity. Recordings will be made 3 months post surgically, after the cysts become stable, and the results compared to myometrium or fat transplant, and unoperated nerves. Because preliminary results revealed the presence of intraneural immune cells, we will determine whether the lesions of endometriosis damage axons. Importantly, we will use not only full thickness uterus, but also isolated endometrium and myometrium, and evaluate the viability of these specific tissues to form cysts. Using immunohistological methods, we will determine the extent of neutrophil and macrophage invasion of the nerve-uterus complex. We will also determine if axons are damaged using ninjurin and fluoro-jade, assessing the presence in both axons and dorsal root ganglion cells. These studies will determine the function and thus the importance of the ectopic innervation of endometrial cysts, as well as the effects of the lesions on through-conducting axons. The results of this study will impacts the understanding of endometriosis pain and seed further research into the pain mechanisms of endometriosis. PUBLIC HEALTH RELEVANCE: In these studies we plan to develop our recently developed model of sciatic endometriosis to make novel inquiries regarding the etiology of endometriosis-related pain. The information that this study will yield stands to improve diagnostic awareness and mechanistic understanding, and thus therapeutic approaches, of the treatment of the symptoms of endometriosis. As a result of this research, consideration and specific examination of nerves within the pelvis during ablative laparoscopic techniques may become an important additional diagnostic procedure for women with endometriosis.