骨癌痛大鼠脊髓背角趋化因子受体5的表达变化

EXPRESSION OF CCR5 IN SPINAL DORSAL HORN IN A RAT MODEL OF BONE CANCER PAIN

目的：探讨骨癌痛大鼠脊髓背角趋化因子受体5（CC chemokine receptor 5,CCR5）表达的变化。方法：雌性SD大鼠32只,体重150～180 g,采用随机数字表法,将其分为2组（n=16）：对照组（C组）和骨癌痛组（BCP组）。采用左胫骨骨髓腔内注入Walker 256细胞的方法制备胫骨癌痛模型。行为学（n=8）：于术前1 d和术后1、3、6、9、12、15 d测定各组大鼠左后肢压爪缩爪阈值（paw withdrawal pressure threshold,PWPT）;于术前1 d及术后15 d,行大鼠左胫骨X线摄片检查。Real-time PCR（n=4）：术前1 d和术后15 d,测定各组大鼠左侧脊髓背角CCR5 m RNA的表达。Western blot（n=4）：术前1 d和术后15 d,测定各组大鼠左侧脊髓背角CCR5蛋白的表达。结果：行为学：与C组相比,术后6～15 d BCP组PWPT明显降低;与术前1 d比较,BCP组术后6～15 d PWPT呈进行性降低。与术前1 d比较,术后15 d BCP大鼠左胫骨X线检查显示有明显的骨皮质破坏及骨小梁缺损。Real-time PCR：与术前1 d及C组比较,BCP组术后15 d左侧脊髓背角CCR5 m RNA表达明显增加。Western blot：与术前1 d及C组比较,BCP组术后15 d左侧脊髓背角CCR5蛋白的表达也显著增加。结论：骨癌痛大鼠脊髓背角CCR5 m RNA及蛋白的表达上调,该变化可能参与了骨癌痛的形成和维持。

Objective： To investigate the changes of the expression of CC chemokine receptor 5（CCR5） in spinal dorsal horn in a rat model of bone cancer pain（BCP）. Methods： Thirty-two female SD rats, weighing 150～180 g, were randomly divided into 2 groups（n = 16）： control（C） group and BCP group. A BCP model was made by inoculation of Walker 256 cells into the intramedullary space of rat tibia. The paw withdrawal pressure threshold（PWPT） was measured at 1d before operation（baseline） and 1, 3, 6, 9, 12, 15 d after operation（n = 8）, and radiology was used to observe bone destruction. The expression of CCR5 m RNA in the ipsilateral spinal dorsal horn（L4 and L5） was measured by real-time PCR（n = 4）1d before operation and 15 d after operation. The expression of CCR5 protein level in ipsilateral spinal dorsal horn was measured by western blot analysis（n = 4）1 d before operation and 15 d after operation. Results： Compared with C group, the PWPT in BCP rats were significantly lower than that of control rats from day 6 to 15. Compared with 1 d before operation, the PWPT progressively decreased in the BCP rats from day 6 to 15. Radiographs of the left tibia of BCP rats showed that signs of cortical bone destruction and radiolucent lesion at day 15 after operation. At 15 d after operation, ipsilateral spinal CCR5 m RNA was markedly increased in BCP group compared with that of control group or baseline. Compared with control group or baseline, the expression of CCR5 at protein level was significantly increased in BCP group. Conclusion： The expression of ipsilateral spinal CCR5 at m RNA and protein levels was upregulated in BCP rats, and these changes may contribute to the development of bone cancer pain.