脊髓IKK2/NF-κB信号通路在大鼠骨癌痛维持中的作用

Role of spinal IKK2/NF-κB signaling pathway in maintenance of bone cancer pain in rats

目的 评价脊髓IκB激酶2（IKK2）/NF-κB信号通路在大鼠骨癌痛维持中的作用.方法 清洁级成年雌性未交配SD大鼠28只,体重160 ～ 200 g,采用随机数字表法分为4组（n=7）：假手术组（S组）、骨癌痛组（BP组）、骨癌痛＋生理盐水组（BN组）和骨癌痛＋BMS345541组（BB组）.BP组、BN组和BB组右侧胫骨骨髓腔注射Walker 256乳腺癌细胞5 μl（4× 105个/ml）,S组注射5μl生理盐水;于术后第10、11和12天,BB组鞘内注射IKK2选择性抑制剂BMS345541 （50 μg/10μl,1次/d）,BN组注射生理盐水（10 μl,1次/d）;于乳腺癌细胞注射前（T0）、注射后7d、第10天注药前1h及注药后1、2、4、12、24h及第12天注药后4 h（T1-8）时测定机械痛阈.于T8时机械痛阈测定后取L4-6脊髓节段,采用Western blot法检测磷酸化NF-κB（p-NF-κB）表达.结果 与S组比较,BP组、BN组和BB组T1-8时MWT降低,脊髓p-NF-κB表达上调（P＜0.05）;与BP组比较,BB组T4-6时MWT升高,脊髓p-NF-κB表达下调（P＜0.01）.结论 脊髓IKK2/NF-κB信号通路参与了大鼠骨癌痛的维持.

Objective To evaluate the role of spinal IKK2/NF-κB pathway in the maintenance of bone cancer pain （BCP） in rats.Methods Twenty-eight unmated adult female Sprague-Dawley rats,weighing 160-200 g,were randomly divided into 4 groups （n =7 each） using a random number table：sham operation group （group S）,BCP group （group BP）,BCP ＋ normal saline group （group BN）,and BCP ＋ BMS345541 group （group BB）.BCP was induced by injecting Walker 256 mammary gland cancer cell suspension 5 μl （4 × 105 cells/ml） into the bone marrow of the right tibia of rats anesthetized with chloral hydrate in BP,BN and BB groups,while the equal volume of normal saline was injected in group S.On 10-12 days after operation,selective IKK2 inhibitor BMS345541 （50 μg/10 μl） was intrathecally injected once a day in group BB,and the equal volume of normal saline （10μl） was given once a day in group BN.The mechanical paw withdrawal threshold （MWT） was measured before intra-tibia injection （T0）,on 7 days after intra-tibia injection （T1）,at 1 h before drug administration and 1,2,4,12 and 24 h after drug administration on day 10 after operation,and at 4 h after drug administration on day 12 after operation （T2-8）.The rats were sacrificed after MWT was measured at Ts and L4-6 segments of the spinal cord were removed for determination of phosphorylated NF-κB （p-NF-κB） expression （using Western blot analysis）.Results Compared with group S,MWT was significantly decreased at T1-2,and the expression of p-NF-κB was up-regulated in BP,BN,and BB groups.Compared with group BP,MWT was significantly increased at T4-6,and the expression of p-NF-κB in the spinal cord was down-regulated in group BB.Conclusion Spinal IKK2/NF-κB signaling pathway is involved in the maintenance of bone cancer pain in rats.