糖尿病大鼠脊髓内高迁移率族蛋白-1参与调节机械性痛敏的机制

The High-mobility Group Box 1 in Spinal Cord of a Rat Model of Diabetic Neuropathic Pain Contributes to Mechanical Allodynia

目的:观察高迁移率族蛋白-1(high mobility group box-1,HMGB1)在糖尿病大鼠脊髓内的表达变化,探索其参与糖尿病性机械性痛觉过敏的具体机制,进一步阐明糖尿病性痛的机制,为糖尿病疼痛的治疗提供新的思路。方法:(1)36只SD大鼠随机分成6组(n=6),分别为正常大鼠组、糖尿病大鼠对照组、糖尿病7 d组、14 d、21 d和28 d组。通过Real-time PCR法检测各组大鼠脊髓内HMGB1 m RNA的表达情况。(2)24只SD大鼠分成4组(n=6)制作糖尿病大鼠模型,在造模后第28 d鞘内给予生理盐水、HMGB1的中和抗体10、30和100μg,检测糖尿病大鼠模型在各时间点的机械性缩足阈值。(3)30只SD大鼠随机分成5组(n=6),其中4组给予链尿佐菌素制作糖尿病大鼠模型。模型制作28 d后鞘内给予生理盐水、HMGB1的中和抗体10、30和100μg。另一组大鼠腹腔给予生理盐水,作为糖尿病大鼠的对照组。检测各组大鼠脊髓的TNF-α、IL-1β和IL-6 m RNA的表达。结果:(1)糖尿病大鼠模型制作21 d和28 d,脊髓内HMGB1 m RNA的表达显著上调(P<0.05)。(2)糖尿病大鼠鞘内给予HMGB1中和抗体30和100μg后,可以在长达24 h的时间内扭转模型大鼠的机械性痛敏(P<0.05)。(3)糖尿病大鼠造模28 d后,鞘内给予HMGB1的中和抗体30和100μg可以明显逆转糖尿病大鼠脊髓内的TNF-α、IL-1β和IL-6 m RNA的表达(P<0.05)。结论:糖尿病大鼠脊髓内HMGB1显著上调,鞘内给予HMGB1的中和抗体可以通过抑制脊髓内TNF-α等细胞因子的表达而扭转糖尿病大鼠的机械性痛敏。以上结果提示,脊髓HMGB1可能参与了糖尿病机械性痛敏状态的维持过程。我们的研究对脊髓HMGB1参与糖尿病大鼠的疼痛的机制进行初步的探讨,为糖尿病性痛的治疗提供新的思路。

Objective： To observe the change of expression of high-mobility group box 1 （HMGB1） in spinal cord of a rat model of diabetic neuropathic pain. To explore the mechanisms involved in diabetic mechanical hyperalgesia. To further illuminate the mechanism of diabetic pain and provide new ideas to diabetes pain treatment. Methods： （1） Thirty-six rats were divided into naive group, sham group, diabetic 7 d group, diabetic 14 d group and diabetic 21 d group. The spinal HMGB1 was measured by Real-time PCR. （2） Twenty-four rats were injected with STZ to build the model of diabetic neuropathic pain. These rats were randomly divided into four groups （n = 6）. 28 days after STZ injection, the effect of spinal HMGB1 on paw withdrawal threshold of diabetic rat was detected by intrathecally injecting saline or the neutralizing antibody, which can go against the function of HMGB1. （3） Thirty rats were randomly divided into five groups （n = 6）. Four of these groups were injected with STZ. The remaining group was not performed any treatment as a normal group. After 28 d, these rats were intrathecally injected saline or neutralizing antibody of HMGB1 to detect the spinal mRNA expression of TNF-a, IL-l[3 and IL-6. Results： （1） The expression ofHMGB1 mRNA in the spinal cord was notable upregulated on 21 d and 28 d after STZ injection （P 〈 0.05）. （2） Intrathecal injection of 30 and 100 p,g neutralizing antibody of HMGB1 could notably inhibit the mechanical hyperalgesia on 28 d after STZ injection （P 〈 0.05）. Its effect could last for 24 h （P 〈 0.05）. （3） Intrathecal injection of 30 and 100 Ixg neutralizing antibody of HMGB could notably cause the spinal mRNA expression of cytokines （TNF-α, IL-1β, and IL-6） on 28 d after STZ injection （P 〈 0.05）. Conclusion： Our research found that the increase of HMGB1 in spinal cord was involved in the paw withdrawal threshold of diabetic rats. The expression of spinal HMGB 1 significantly increased in diabetic rats. Intrathecal administration of HMGB1 neutralizing antibody could inhibit the expression of TNF-a and other cytokines in the spinal cord and could reserve the mechanical hyperalgesia in diabetic rats. These results suggest that the increase of HMGB1 in spinal cord was involved in the paw withdrawal threshold of diabetic rats. Our research initially explored the mechanism of diabetic pain and could provide new ideas to diabetes pain treatment.