白藜芦醇对腰神经根周围自体髓核移植大鼠背根神经节TNF-α和IL-1表达的影响

Effect of resveratrol on the expression of TNF-α and IL-1 in dorsal root ganglion neuron after auto-transplantation of nucleus pulposus in rat model

目的:观察白藜芦醇对腰神经根周围自体髓核移植大鼠脊髓背根神经节(DRG)中肿瘤坏死因子(TNF-α)和白介素-1(IL-1)表达的影响。方法:SD大鼠48只,随机分为脂肪+生理盐水组(A组)、髓核+生理盐水组(B组)、髓核+地塞米松组(C组)、髓核+白藜芦醇组(D组),每组12只。所有大鼠行椎板切除开窗,暴露左侧的硬脊膜及L4、L5背侧神经根,其中B、C、D组制作腰神经根周围自体髓核组织移植动物模型,A组制作腰神经根周围自体脂肪组织移植动物模型。术后第7天各组随机处死6只大鼠并取材,剩余大鼠D组给予腹腔注射白藜芦醇,C组腹腔注射地塞米松,A、B组则给予等量生理盐水腹腔注射,1次/d,连续5d,术后第14天取材。对两个时间点各组大鼠的L4、L5脊髓DRG行HE染色、TNF-α和IL-1免疫组化染色,光镜下观察并计算阳性细胞数,所得数据用SPSS 17.0统计软件进行分析。结果:A组无明显炎性反应,B、C、D组术后7d时DRG内细胞间组织增宽,呈明显充血和水肿,神经节细胞尼氏小体消失,空泡变性,核消失,炎性细胞大量浸润,微血管扩张,部分髓鞘呈空泡样变;术后14d时B组炎性表现仍较明显,C组和D组相对B组神经根节内的病理变化较轻,尼氏小体略有减少,少量空泡变性及炎性细胞浸润,髓鞘变化也较轻。B、C、D组与A组相比,术后7d、14d时背根神经节细胞TNF-α和IL-1表达均显著增加(P<0.01);14d时,C、D组与B组相比,TNF-α和IL-1表达显著降低(P<0.01),C组与D组相比无统计意义(P>0.05)。结论:髓核自体移植至脊髓DRG周围可造成神经根局部炎症反应,白藜芦醇可以降低其背根神经节细胞TNF-α和IL-1的表达,从而减轻炎症反应。

Objectives： To observe the effect of resveratrol on the expression of TNF-α and IL-1 in dorsal root ganglion（DRG） neuron after auto-transplantation of nuclear pulposus in rat model. Methods： Forty-eight Sprague-Dawley rats were divided randomly into 4 groups： fat＋normal saline group（group A）, nucleus pulposus＋normal saline group（group B）, nucleus pulposus＋dexamethasone（group C） and nucleus pulposus＋resveratrol group（group D）, with 12 rats in each group. All rats underwent laminectomy, which exposed the dorsal nerve root of left L4 and L5, and then in group B, C and D, autologous nucleus pulposus was transplanted around the nerve root, while in group A, autologous adipose tissue was transplanted instead. Sevens days after operation, six rats in each group were killed randomly and the left dorsal nerve roots were obtained, while the other rats in group D, resveratrol was given by intraperitoneal injection once a day and lasted for 5 days. In group C dexamethason was given, and in group A and B, saline was given in the same way. Then, at the 14th day, dorsal nerve roots of left L4 and L5 obtained from the other rats experienced HE staining, immunohistochemical staining（IHC） for TNF-α and IL-1, the TNF-α positive cells and the IL-1 apoptosis cells were measured under light microscope. The experimental data were analyzed by SPSS 17.0 statistical software. Results： There was no significant inflammatory reaction in group A. At 7 days, in group B, C, D, the arrangement between cells in DRG were loose and presented hyperemia and edema, ganglion cells Nissl bodies disappeared, vacuolar degeneration, nucleus disappearance, inflammatory cells infiltration, capillary dilatation, vacuolar degeneration in some myelin were evidenced. At 14 days, the inflammatory reaction was still evidenced in group B, while the pathological changes in the DRG were lighter in group C and D compared with group B, which included fewer disappearance of nissl bodies, just fewer vacuoles degeneration in nissl bodies and fewer inflammatory cell infiltration, and also the myelin vacuolar degeneration was lighter. The expressions of TNF- α and IL-1 in group B, C and D were apparently higher than group A at 7 and 14 days（P〈0.01）. The expressions of TNF-α and IL-1 in group C and D were apparently lower compared with group B（P〈0.01） at 14 days, but there was no difference between group C and D（P〉0.05）. Conclusions： Autologous nucleus pulposus can induce inflammatory reaction in the DRGs. Resveratrol can alleviate the reaction through reducing the expression of TNF-α and IL-1 in DRGs.