SP, CGRP对骨质疏松性疼痛和骨代谢的影响及相关机制研究

Substance P (SP) and calcitonin gene-related peptide (CGRP) are important regulatory neuropeptides released by sensory nerves, and involved with the bone metabolism at the same time. Our previous works showed that SP, CGRP may play an essential role in osteoporotic pain, which were closely related to the lost content of bone mass and the aggressive degree of pain in patients with bone and joint degenerative disease. While the exact effect and mechanism of SP, CGRP for the osteoporotic pain is still poorly understood. The present study we will investigate the relationships between the neuropeptides and pain, bone metabolism, bone mineral density, bone quality in the serum and the bone tissue of osteoporotic patients. And the changes of neuropeptides and cytokines IL-1β, IL-6, TNF-α were also detected with its effect on pain, bone metabolism, bone mineral density and bone quality index in the nervous system, the serum and the bone tissue of osteoporotic rat model by using morphology, microCT and molecular biology methods. The neuropeptide antagonists were used to clarify the efficiency on the above index. The purpose of this study is to further expose the role of neuropeptide on bone metabolism and osteoporotic pain, and shed a new light on our understanding of the pathogenesis and mechanism. This study will provide new experimental evidence for the osteoporosis prevention and treatment of osteoporotic pain.

神经肽P物质(SP)和降钙素基因相关肽(CGRP)是感觉神经末梢释放的重要疼痛介质，同时参与机体的骨代谢活动。我们前期工作证实SP,CGRP在退行性骨关节疾病患者松质骨内的表达和疼痛程度有密切关系，提示神经肽可能在骨质疏松性疼痛中发挥了作用，但SP,CGRP对于骨质疏松及所致疼痛的确切影响和作用机制尚不明确。本课题拟采用组织形态学、microCT和分子生物学等方法，观察骨质疏松患者血清和骨组织中神经肽与疼痛、骨代谢、骨量和骨质量的关系；骨质疏松模型大鼠的神经系统，血清和骨组织中神经肽及相关细胞因子IL-1β,IL-6,TNF-α表达的变化，明确其对疼痛、骨代谢、骨量和骨质量指标的影响，以及神经肽拮抗剂对上述指标的影响效能，分析神经肽参与骨质疏松性疼痛和骨代谢的方式与途径，进一步阐明神经肽对骨代谢异常及骨质疏松性疼痛的作用和相关机制，从而为骨质疏松防治及疼痛治疗提供新的研究基础和理论依据。

通过本课题的实施，我们初步阐明神经肽对骨代谢异常及骨质疏松性疼痛的作用和相关机制，从而为骨质疏松防治及疼痛治疗提供新的研究基础和理论依据。人体实验研究发现：骨关节炎和骨质疏松患者的视觉模拟评分法(VAS)分别为5.6±1.1分和1.4±0.9分，差异有显著性(P<0.05)。Micro-CT检测：OA组的表观密度、BV/TV、Tb.Th、和OP组比较有显著性升高，OA组的SMI和OP组比较有显著性下降。免疫组化分析：OA组SP，CGRP和VIP的平均光密度值比OP组有显著性升高，OA组NPY的平均光密度值比OP组有显著性下降。相关关系研究发现患者微结构参数中的骨体积分数(BV/TV)与VIP的平均光密度值呈正相关关系，与 NPY的平均光密度值呈负相关关系；结构模型指数(SMI) 与VIP的平均光密度值呈负相关关系，与 NPY的平均光密度值呈正相关关系。SP，CGRP和VIP的平均光密度值与疼痛VAS评分成正相关，NPY成负相关。动物实验研究发现，OVX组大鼠机械痛阈明显高于假手术组，而温痛阈两组之间没有差异。OVX组的极限应力比对照组有显著性下降。OVX组大鼠胫骨骨小梁纳米硬度和弹性模量明显低于对照组。免疫组化分析显示大鼠骨硬组织切片和背根神经节内SP，CGRP成功染色，骨硬组织切片中OVX组SP平均光密度值低于对照组，而DRG内OVX组SP平均光密度值明显高于对照组。在相关关系研究发现骨硬组织切片中SP平均光密度值与大鼠机械痛阈呈正相关关系。