血管内皮生长因子抗体缓解大鼠糖尿病周围神经痛

Vascular endothelial growth factor antibody attenuates diabetic peripheral neuropathic pain in rats

目的:探讨血管内皮生长因子(vascular endothelial growth factor,VEGF)在大鼠糖尿病周围神经痛(diabetic peripheral neuropathic pain,DPNP)发病机制中的作用。方法:24只8周Sprague-Dawley雄性大鼠,随机分为3组,每组8只:对照组(C组),单次腹腔注射柠檬酸钠溶液10 mL/kg;模型组(M组),单次腹腔注射链脲佐菌素(streptozotocin,STZ)65 mg/kg;干预组(T组),单次腹腔注射STZ 65mg/kg建立模型,且在造模后第1,3,7,10天分别单次腹腔注射抗VEGF抗体10 mg/kg。C组和M组分别在相同时间点腹腔注射等体积柠檬酸钠溶液。注射STZ前1 d(基础值)、注射STZ后第1,3,7,14天检测大鼠空腹血糖值;注射STZ前1 d、注射STZ后第1,3,5,7,10,14天分别测定大鼠体重及后足机械痛阈和热痛阈;应用Western印迹法测定腰段脊髓磷酸化蛋白激酶B(phospho protein kinase B,p-Akt)和瞬时受体电位香草酸亚型1(transient receptor potential vanilloid 1,TRPV1)的蛋白表达。结果:注射STZ后,M组及T组大鼠与C组大鼠各时间点体重差异有统计学意义,C组大鼠体重增加(P<0.01)。与C组大鼠相同时间点比较,M组及T组大鼠空腹血糖升高(P<0.01)。3组大鼠足底机械缩足反射阈值(paw withdraw mechanical threshold,PWMT)和足底皮肤热刺激缩足反射潜伏期(paw withdraw thermal latency,PWTL)随时间变化差异有统计学意义(P<0.01),与C组相同时间点比较,M组(第3,5,7,10,14天)及T组(第5,7,10,14天)PWMT和PWTL降低(P<0.01)。与M组比较,T组大鼠第10和14天PWMT和PWTL升高(P<0.01或P<0.05)。与C组比较,M组和T组大鼠脊髓p-Akt和TRPV1表达升高(P<0.01);与M组比较,T组大鼠p-Akt和TRPV1表达降低(P<0.01)。结论:VEGF可能通过磷脂酰肌醇-3-激酶/蛋白激酶B(phosphatidylinositol 3-kinase/protein kinase B,PI3K/Akt)信号通路调控TRPV1的表达参与大鼠DPNP,抗VEGF治疗可能成为DPNP治疗的靶点之一。

Objective： To explore the role of vascular endothelial growth factor （VEGF） in diabetic peripheral neuropathic pain in rats. Methods： Twenty-four adult male Sprague-Dawley rats aged 8 weeks were randomly divided into 3 groups （n=8 per group）. The control group （C group）： rats were intraperitoneally injected with sodium citrate solution at 10 mL/kg; the model group （M group）： rats were intraperitoneally injected with streptozotocin at 65 mg/kg; the treatment group （T group）： rats received intraperitoneal injection of anti-VEGF antibody （10 mg/kg） at the 1st, 3rd, 7th, 10th day after STZ treatment. Meanwhile, rats of C and M group were received with the same volume of sodium citrate solution. Blood glucose was measured before 1 day or at the 1st, 3rd, 7th or 14th day after receiving STZ. Body weight, paw withdrawal mechanical threshold （PWMT） and paw withdrawal thermal latency （PWTL） were measured before 1 day or at the 1st, 3rd, 5th, 7th, 10th or 14th day after receiving STZ. All lumbar spinal cords were dissected to examine the p-protein kinase B （p-Akt） and transient receptor potential vanilloid 1 （TRPV1） expression by Western blot. Results： After injection with STZ, the body weight showed significant differences at some time point between the M, T or C group （P〈0.01）; body weight of rat in the C group were increased gradually. Compared with the C group, the fast blood glucose in the M or the T Group at the same time points were increased significantly （P〈0.01）. The PWMT and PWTL of the M, T or C group were significant difference among various time points （P〈0.01）. The PWMT and PWTL in the M or T group were obviously reduced compared with those in the C group （P〈0.01）. Compared with the M group, the PWMT and PWTL in the T group were increased at the 10th or 14th day （P〈0.01 or P〈0.05）. Compared with the C group, the p-Akt and TRPV1 levels in the M and T group were increased （P〈0.01）. Compared with the M group, p-Akt and TRPV1 levels in T group were decreased （P〈0.01）. Conclusion： VEGF is able to regulate the expression of TRPV1 through PI3K/Akt pathway, which contributes to diabetic peripheral neuropathic pain in rats. Anti-VEGF treatment may be useful for alleviation of diabetic peripheral neuropathic pain.