肾上腺髓质素参与骨癌痛和神经病理性痛的发生及其机制

发布时间：2018-08-19 15:24

【摘要】：肾上腺髓质素(adrenomedullin, AM)属于降钙素基因相关肽(calcitonin gene-related peptide, CGRP)家族,广泛存在于脊髓背角浅层与背根神经节(DRG)的肽能和非肽能神经元。研究指出,AM是一种痛介导质,但其参与慢性神经痛的机制尚未清晰。为探索AM在神经病理性痛发生和维持过程的作用机制,以及与CGRP、白细胞介素-1β(interleukin 1β, IL-1β)、NO之问的关系,本研究建立在骨癌痛、L5脊神经结扎SNL基础上,采用影像学、行为学、免疫组织化学和实时荧光定量PCR (quantitative real-time polymerase chain reaction, qRT-PCR)等实验技术探讨：(1)骨癌引起大鼠组织学、行为学的变化；(2)骨癌痛诱发大鼠脊髓背角和DRG中AM、CGRP和nNOS的表达情况；(3)AM特异性受体拮抗剂AM22-52对骨癌诱发大鼠痛觉过敏和AM、CGRP、NOS表达的影响；(4)SNL大鼠机械痛阈值的变化以及AM、CGRP、IL-1β的表达情况；(5)鞘内注射AM22-52对SNL大鼠行为学的影响；(6)鞘内注射AM22-52 对 SNL诱发大鼠脊髓和DRG中AM、CGRP、IL-1β表达的影响。实验结果如下：(1)骨癌大鼠第7天出现体重下降、明显的骨破坏现象,并产生机械痛觉过敏和热痛觉过敏。(2)骨癌痛引起AM及其受体、CGRP和nNOS在脊髓背角和DRG中表达增加,染色显示AM主要分布于DRG中、小型神经元。(3)鞘内注射AM22-52,翻转了骨癌痛诱发的痛觉过敏及脊髓背角和DRG内AM、CGRP、NOS的表达增加。(4)大鼠脊神经结扎处理后第10天机械阈值下降50%左右,产生痛觉过敏。DRG和脊髓背角中AM、CGRP、IL-1β的表达明显增加。(5)鞘内注射AM22-52可缓解SNL引发的痛觉过敏。(6)鞘内注射AM22-52可明显缓解脊髓和L4中CGRP表达增加,而AM和IL-1p表达量反而升高。以上研究结果表明,骨痛和神经损伤能诱导AM合成增加,阻断AM受体可明显缓解疼痛；神经病理性痛诱导的细胞信号级联反应中,AM可能是使促痫介质CGRP和促炎性细胞因子IL-1β、nNOS等表达增加的上游因子。与此同时,除AM、CGRP通路以外,可能存在免疫机制或其他潜在的信号通路诱导促炎因子IL-1β的表达,参与疼痛的发生。
[Abstract]:Adrenomedullin (AM) belongs to the calcitonin gene-related peptide (CGRP) family and widely exists in peptidergic and non-peptidergic neurons in the superficial layer of spinal dorsal horn and dorsal root ganglion (DRG). This study was based on bone cancer pain, L5 spinal nerve ligation SNL, using imaging, behavioral, immunohistochemical and quantitative real-time polymerase chain reaction (quantitative real-time polymerase chain reaction). Experimental techniques such as ain reaction and qRT-PCR were used to investigate: (1) histological and behavioral changes induced by bone cancer in rats; (2) expression of AM, CGRP and nNOS in spinal dorsal horn and DRG induced by bone cancer pain in rats; (3) effect of AM22-52 on hyperalgesia and expression of AM, CGRP and NOS induced by bone cancer in rats; (4) mechanical pain in SNL rats The changes of the threshold and the expression of AM, CGRP and IL-1 beta were observed; (5) the effect of intrathecal injection of AM22-52 on the behavior of SNL rats; (6) the effect of intrathecal injection of AM22-52 on the expression of AM, CGRP and IL-1 beta in spinal cord and DRG of rats induced by SNL. (3) Intrathecal injection of AM22-52 reversed the hyperalgesia induced by bone cancer pain and increased the expression of AM, CGRP and NOS in spinal dorsal horn and DRG in rats. (4) The expression of AM, CGRP and NOS in spinal nerve node was increased in rats. On the 10th day after ligation, the mechanical threshold decreased by about 50%, resulting in hyperalgesia. The expression of AM, CGRP and IL-1 beta in DRG and dorsal horn of spinal cord increased significantly. (5) Intrathecal injection of AM22-52 could alleviate the hyperalgesia induced by SNL. (6) Intrathecal injection of AM22-52 could significantly alleviate the increase of CGRP expression in spinal cord and L4, while the expression of AM and IL-1p increased. The results showed that bone pain and nerve injury could induce the increase of AM synthesis and blockade of AM receptor could alleviate pain. AM may be an upstream factor in the signal cascade reaction induced by neuropathic pain, which may increase the expression of CGRP, IL-1beta, nNOS and other inflammatory cytokines. The mechanism or other potential signaling pathways induce the expression of proinflammatory cytokines IL-1 beta and participate in the occurrence of pain.
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R402

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