骨癌痛大鼠脊髓神经元Piezo2表达的变化

Changes in expression of Piezo2 in spinal cord neurons in a rat model of bone cancer pain

目的 评价骨癌痛大鼠脊髓神经元Piezo2表达的变化.方法 清洁级健康成年雌性未交配SD大鼠64只,体重160～ 200 g.采用随机数字表法分为2组（n=32）：假手术组（S组）和骨癌痛组（BP组）.BP组制备大鼠骨癌痛模型,于接种肿瘤细胞前1d、接种后7、14和21 d（T0-3）时测定机械缩足反应阈（MWT）后,随机取8只大鼠处死取脊髓腰膨大节段,采用Western blot法及免疫荧光法检测Piezo2的表达.免疫荧光双标法检测T2时脊髓腰膨大Piezo2与神经元标志物NeuN、小胶质细胞标志物Iba-1、星形胶质细胞标志物GFAP的共表达.结果 与S组比较,BP组大鼠T1.3时MWT降低,脊髓腰膨大节段Piezo2表达上调（P＜0.05）.Piezo2主要表达在脊髓背角第Ⅰ、Ⅱ板层,且Piezo2几乎与NeuN共表达,而很少与GFAP和Iba-1共表达.结论 大鼠骨癌痛的形成和维持与脊髓腰膨大节段神经元Piezo2表达上调有关.

Objective To evaluate the changes in the expression of Piezo2 in spinal cord neurons in a rat model of bone cancer pain.Methods Sixty-four pathogen-free healthy adult female unmated Sprague-Dawley rats,weighing 160-200 g,were divided into 2 groups （n=32 each） using a random number table：sham operation group （group S） and bone cancer pain group （group BP）.Bone cancer pain was induced by injecting breast cancer cells into the abdominal cavity.The mechanical paw withdrawal threshold （MWT） was measured at 1 day before inoculating breast cancer cells and 7,14 and 21 days after inoculation （T0-3）.Eight rats were sacrificed after measurement of MWT,and their lumbar enlargement segments of the spinal cord were removed for determination of Piezo2 expression by Western blot and immunofluorescence.The coexpression of Piezo2 with the neuronal marker NeuN,microglial marker Iba-1 and astrocyte marker GFAP was detected at T2 using double immunofluorescent staining.Results Compared with group S,the MWT was significandy decreased at T1-3,and the Piezo2 expression in the lumbar enlargement segment of the spinal cord was up-regulated in group BP （P 〈 0.05）.Piezo2 was mainly expressed in the spinal lamina Ⅰ and Ⅱ and co-expressed with NeuN and rarely co-expressed with GFAP or Iba-1.Conclusion The development and maintenance of bone cancer pain are related to up-regulated expression of Piezo2 in the lumbar enlargement segment of the spinal cord in rats.