Qiu Fang, Wei Xiaoli, Zhang Shuzhuo, Yuan Weixiu, Mi Weidong
aAnesthesia and Operation Center, Chinese PLA General Hospital bInstitute of Pharmacology and Toxicology, Academy of Military Medical Sciences, Beijing, China.
Neuroreport. 2014 Aug 20;25(12):887-93. doi: 10.1097/WNR.0000000000000182.
In an attempt to investigate the underlying mechanisms of cancer-induced bone pain, we investigated the presence of acid-sensing ion channel 3 (ASIC3) in dorsal root ganglia (DRG) neurons in an animal model of bone cancer pain. Forty-five female Sprague-Dawley rats were randomized into three groups: sham-operation group (sham), cancer-bearing animals killed after 7 days (C7), and cancer-bearing animals killed after 14 days (C14). After establishment of the bone cancer pain model, pain-related behavioral tests were performed to determine the paw withdrawal threshold of mechanical allodynia and thermal hyperalgesia, respectively. Reverse transcription-PCR, western blot, and immunofluorescence were used to determine mRNA and protein expression of ASIC3 in ipsilateral and contralateral lumbar 4-5 DRG neurons. Compared with the sham group, paw withdrawal threshold of mechanical allodynia and thermal hyperalgesia in the C14 group showed a significant decrease (P<0.01) from postoperation day 7 to the termination of the experiment. Compared with the sham group, the ipsilateral but not contralateral mRNA of ASIC3 was upregulated in the C14 group. Meanwhile, the ipsilateral protein expression of ASIC3 was increased in the C7 and C14 group compared with the sham group. Double-labeled immunofluorescence showed that ASIC3 and isolectin-B4 (IB4)-colocalized small DRG neurons in the C14 group were more than that in the sham group. Furthermore, we also found that there were more ASIC3 and neurofilament 200 (NF200)-colocalized DRG neurons in the C14 group than in the sham group. The upregulation of mRNA and protein levels of ASIC3 suggested its potential involvement in the development and maintenance of cancer-induced bone pain.
为了探究癌症诱发骨痛的潜在机制，我们在骨癌痛动物模型中研究了背根神经节（DRG）神经元中酸敏感离子通道3（ASIC3）的存在情况。45只雌性Sprague-Dawley大鼠被随机分为三组：假手术组（sham）、7天后处死的荷瘤动物组（C7）和14天后处死的荷瘤动物组（C14）。建立骨癌痛模型后，分别进行疼痛相关行为测试以确定机械性异常性疼痛和热痛觉过敏的爪退缩阈值。采用逆转录聚合酶链反应（RT-PCR）、蛋白质免疫印迹法（western blot）和免疫荧光法来测定同侧和对侧腰4-5 DRG神经元中ASIC3的mRNA和蛋白表达。与假手术组相比，C14组从术后第7天至实验结束时，机械性异常性疼痛和热痛觉过敏的爪退缩阈值显著降低（P<0.01）。与假手术组相比，C14组同侧而非对侧的ASIC3 mRNA上调。同时，与假手术组相比，C7组和C14组同侧ASIC3蛋白表达增加。双标免疫荧光显示，C14组中ASIC3与异凝集素B4（IB4）共定位的小DRG神经元比假手术组更多。此外，我们还发现，C14组中ASIC3与神经丝200（NF200）共定位的DRG神经元比假手术组更多。ASIC3 mRNA和蛋白水平的上调表明其可能参与癌症诱发骨痛的发生和维持。
