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有明显的疼痛。现代研究表明子宫内膜囊肿的新神经支配是这种疼痛的主要来源。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活跃，或者在什么情况下活跃。目前还没有研究表明子宫内膜病变对神经或轴突的功能影响。我们实验室主要研究炎症对轴突的影响。我们已经表明，神经炎症诱导伤害感受器轴突的异位机械敏感性，这是不敏感的。我们的数据还表明，神经炎症诱导炎症部位和/或细胞体的持续活动，并且在神经炎症期间交感神经元活动减少。最近我们将大鼠子宫内膜异位症的模型调整为累及坐骨神经。该模型与大鼠子宫内膜异位症模型非常相似，将子宫的一部分移植到腹腔内部位。在初步资料中，子宫部分被移植到坐骨神经。提出了三种互补的电生理方法来确定子宫、子宫内膜和肌层对坐骨神经影响的特点。首先，要确定通导轴突的比例。然后，在一些实验中，从背根进行梳理纤维记录，在其他实验中，从周围神经的远端进行梳理纤维记录。这种方法的结合提供了优势，可以研究通过囊肿的感觉和交感轴突，以及支配囊肿的轴突。我们将确定靠近囊肿或直接支配囊肿的轴突是否发展出持续的活动和/或机械敏感性。术后3个月，囊肿稳定后进行记录，并将结果与肌层或脂肪移植和未手术神经进行比较。由于初步结果显示神经内免疫细胞的存在，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肌层，并评估这些特定组织形成囊肿的可行性。利用免疫组织学方法，我们将确定中性粒细胞和巨噬细胞侵袭神经-子宫复合体的程度。我们还将使用忍者素和氟玉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，以及病变对传导轴突的影响。本研究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。

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.