Leni and Peter W. May Department of Orthopaedics, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy, Place, Box 1188, New York, NY, 10029-6574, USA.
Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Sci Rep. 2020 Sep 15;10(1):15120. doi: 10.1038/s41598-020-72081-9.
Back pain is linked to intervertebral disc (IVD) degeneration, but clinical studies show the relationship is complex. This study assessed whether males and females have distinct relationships between IVD degeneration and pain using an in vivo rat model. Forty-eight male and female Sprague-Dawley rats had lumbar IVD puncture or sham surgery. Six weeks after surgery, IVDs were evaluated by radiologic IVD height, histological grading, and biomechanical testing. Pain was assessed by von Frey assay and dorsal root ganglia (DRG) expression of Calca and Tac1 genes. Network analysis visualized which measures of IVD degeneration most related to pain by sex. In both females and males, annular puncture induced structural IVD degeneration, but functional biomechanical properties were similar to sham. Females and males had distinct differences in mechanical allodynia and DRG gene expression, even though sex differences in IVD measurements were limited. Network analysis also differed by sex, with more associations between annular puncture injury and pain in the male network. Sex differences exist in the interactions between IVD degeneration and pain. Limited correlation between measures of pain and IVD degeneration highlights the need to evaluate pain or nociception in IVD degeneration models to better understand nervous system involvement in discogenic pain.
背痛与椎间盘（IVD）退变有关，但临床研究表明两者之间的关系很复杂。本研究使用体内大鼠模型评估了男性和女性的 IVD 退变与疼痛之间是否存在独特的关系。48 只雄性和雌性 Sprague-Dawley 大鼠进行了腰椎 IVD 穿刺或假手术。手术后 6 周，通过放射学 IVD 高度、组织学分级和生物力学测试评估 IVD。通过 von Frey 测定法和背根神经节（DRG）中 Calca 和 Tac1 基因的表达评估疼痛。网络分析可视化了 IVD 退变的哪些指标与性别相关的疼痛最相关。在女性和男性中，环形穿刺都会导致 IVD 结构退变，但功能生物力学特性与假手术相似。尽管 IVD 测量值的性别差异有限，但女性和男性在机械性痛觉过敏和 DRG 基因表达方面存在明显差异。网络分析也因性别而异，男性网络中环形穿刺损伤与疼痛之间的关联更多。IVD 退变与疼痛之间的相互作用存在性别差异。疼痛和 IVD 退变测量值之间的相关性有限，这突出表明需要在 IVD 退变模型中评估疼痛或伤害感受，以更好地了解椎间盘源性疼痛中神经系统的参与。
