白介素18髓核内注射对兔椎间盘作用的实验研究

Effects of Interleukin-18 on the Degeneration of Rabbit Lumbar Intervertebral Disc

为探讨白介素18（IL-18）髓核内注射对兔椎间盘蛋白多聚糖和基质金属蛋白酶-3（MMP-3）的影响。方法采用健康大白兔72只,体重2.5~3 kg。随机分为实验组48只,阴性对照组16只,空白对照组8只。实验组（IL-18组）：随机分为3组,每组16只。选择L4~L5椎间盘,分别注射浓度为10 ng/μL2、0 ng/μL、40 ng/μL的IL-18各1μL。阴性对照组（生理盐水组）：椎间盘内注射1μL的生理盐水。空白对照组：不作任何处理。分别于第3、6周取相应椎间盘作HE染色、免疫组织化学法检测MMP-3的表达及蛋白多聚糖含量测定。结果显示：①HE染色显示,随着IL-18浓度加大,髓核中细胞数量减少,正常组织结构破坏越严重,空泡状结构减少,细胞核的形态由椭圆形变为多种形态。②3周时阴性对照组及空白对照组髓核蛋白多聚糖没有明显变化,实验组蛋白多聚糖下降明显（15.72%~43.78%,P〈0.001）。6周时阴性对照组及实验组与空白对照组髓核蛋白多聚糖比较差异有统计学意义（P〈0.05）,并且实验组蛋白多聚糖下降程度与IL-18注射剂量呈正相关（P〈0.05））。③实验组均发现表达MMP-3的阳性细胞,随时间延长阳性细胞数量逐渐增多,并且阳性率与IL-18注射剂量及时间呈正相关（P〈0.05）。3周时阴性对照组及空白对照组很少发现表达MMP-3的阳性细胞,而6周时阴性对照组MMP-3的阳性细胞表达增多,与空白对照组比较差异有统计学意义（P〈0.05）。结论：椎间盘内注射IL-18能够导致椎间盘内蛋白多聚糖含量降低,促进腰椎间盘内基质金属蛋白酶-3（MMP-3）的表达,可能加速椎间盘的退变,并且有量效关系。

To investigate the in vivo effects of IL-18 on the content of aggrecan and the expression of MMP-3 on the intervertebral disc.Seventy-two healthy rabbits were randomly divided into three groups,including control group（no intervention of the disc）,IL-18 group（IL-18 injectde into the intervertebral discs）and NaCl group（NaCl injectde into the intervertebral discs）.L4/5 intervertebral discs were exposed surgically,0.9% NaCl（1 μL）and various concentrations（10 ng/μL,20 ng/μL and 40 ng/μL） of IL-18（1 μL） were respectiyely injected into L4/5 intervertebral discs.Aggrecan content neasuring and expression of MMP-3 on intervertebral disc were done when the animals were killed in the third and sixth weeks.Results Showed①The HE-staining showed that with the increase of IL-18 the amount of nucleus pulposus cells decreased,reticular framework was broken down,vacuole shape disappeared and oval nucleolus of cells became multishape.②In the third week,content of aggrecan had not changed apparently in control and NaCl groups,but in the experiment groups rapid decline（15.72%～43.78%,P0.001）was evidenced.In the sixth week,content of aggrecan in Nacl group and experiment groups decline（P0.05）,and experiment groups decline were more correlative with the dose of IL-18（P0.05）.③In IL-18 groups the MMP-3 mascuLine cells had homogeneous distribution puncti form moth patch and were increase with the concentrations and the time（P0.05）.ln the third week,there was little expression of MMP-3 in control and NaCl group,but in the sixth week the expression of MMP-3 in NaCl group increased（P0.05）.IL-18 injected into the intervertebral discs can lead to decline of aggrecan and morphologicaL changes in the nucleus pulposus,which were related with dose of IL-18 adminstration.