三种腰椎间盘突出症大鼠模型制备方法的比较与评价

Comparison and evaluation of three different methods for preparing rat models of lumbar disc herniation

背景:目前实验中有多种腰椎间盘突出症大鼠模型,但各自存在一定的优缺点,其中最常见的造模方法包括自体髓核移植和纤维环穿刺模型。目的:建立自体髓核移植模型(剪除棘突+乳突/剪除侧突+乳突)以及纤维环穿刺模型,比较及评估3种模型的特点。方法:将40只成年雄性SD大鼠随机分为4组,每组10只,分别为假手术组、棘突组、侧突组及纤维环穿刺组,其中假手术组大鼠仅切开皮肤,暴露棘突后并缝合;棘突组大鼠剪除L5棘突和乳突并取2枚尾椎髓核放于椎间孔处;侧突组大鼠剪除L5侧突和乳突并取2枚尾椎髓核放于椎间孔处;纤维环穿刺组大鼠剪除乳突后,进行纤维环穿刺术,并行椎间盘注射白细胞介素1β。分别在造模前和造模后检测大鼠热缩足潜伏期,造模结束后2周进行腰椎MRI检测;苏木精-伊红染色和番红-固绿染色观察椎间盘病理改变;免疫荧光观察CD68阳性表达。结果与结论:①热痛阈检测结果显示:与假手术组相比,模型组大鼠在造模后痛觉敏感均降低,耐受时间均降低(P<0.05);②腰椎MRI影像显示:棘突组和纤维环穿刺组髓核组织突出明显,更符合常见腰椎间盘突出患者MRI影像;③苏木精-伊红染色观察:与假手术组比较,各模型组髓核组织存在不同程度退变,炎性细胞浸润和脊索细胞降解,出现空洞样改变,其中纤维环穿刺组病理改变最严重;④番红-固绿染色显示:与假手术组比较,3组模型的髓核组织边界模糊,存在广泛炎性反应,纤维环存在不同程度退变;⑤CD68+免疫荧光阳性结果显示:与假手术组相比,3组模型的CD68+表达更高、范围更广,其中纤维环穿刺组表达最高。结果说明3种方法均能有效建立腰椎间盘突出大鼠模型,其中剪除乳突后建立纤维环穿刺模型优于剪除棘突+乳突组自体髓核移植模型,前2种模型优于剪除侧突+乳突组自体髓核移植模型。

BACKGROUND:Currently,there are various rat models of lumbar disc herniation used in experiments,each with its own advantages and disadvantages.The most common modeling methods include autologous nucleus pulposus transplantation and annulus fibrosus puncture models.OBJECTIVE:To establish two autologous nucleus pulposus transplantation models(with spinous process and mastoid process excision and with transverse process and mastoid process excision)as well as an annulus fibrosus puncture model,and to compare and evaluate the characteristics of the three models.METHODS:Forty male adult Sprague-Dawley rats were randomly divided into four groups(n=10 per group):sham surgery group,spinous process group,transverse process group,and annulus fibrosus puncture group.In the sham surgery group,surgical preparation was performed,the skin was incised,and the spinous process was exposed,and then sutured.In the spinous process group,L5 spinous process and transverse process were excised,and two pieces of tail nucleus pulposus were placed in the intervertebral foramen.In the transverse process group,L5 transverse process and transverse process were excised,and two pieces of tail nucleus pulposus were placed in the intervertebral foramen.In the annulus fibrosus puncture group,the transverse process was excised and annulus fibrosus puncture and intervertebral disc injection of interleukin 1βwere then performed.Thermal paw withdrawal latencies were tested before and after modeling.Lumbar spine MRI was performed 2 weeks after modeling.Pathological changes in the intervertebral discs were observed using hematoxylineosin staining and safranin-O-fast green staining.Immunofluorescence was used to observe CD68+positive expression.RESULTS AND CONCLUSION:(1)Thermal withdrawal threshold testing results showed that compared with the sham surgery group,pain sensitivity and tolerance time of rats decreased significantly after modeling(P<0.05).(2)Lumbar spine MRI images showed that the spinous process and transverse process groups had obvious protrusion of nucleus pulposus tissue,which more closely resembled MRI images of patients with common lumbar disc herniation.(3)Hematoxylin-eosin staining revealed that compared with the sham surgery group,nucleus pulposus tissues in the model groups showed varying degrees of degeneration,inflammatory cell infiltration,and degradation of spinal cord cells,with the appearance of cystic changes,among which the annulus fibrosus puncture group had the most severe pathological changes.(4)Safranin-O-fast green staining showed that compared with the sham surgery group,the boundaries of nucleus pulposus tissues in the three model groups were blurred,with extensive inflammatory reactions and varying degrees of degeneration in the annulus fibrosus.(5)CD68+immunofluorescence staining results showed that compared with the sham surgery group,the expression of CD68+in the model groups was higher and more widespread,with the annulus fibrosus puncture model showing the highest expression.All the three methods could be used to effectively establish rat models of lumbar disc herniation,with the annulus fibrosus puncture model established after excision of the transverse process being superior to the autologous nucleus pulposus transplantation model(spinous process+mastoid process),and the first two models being superior to the autologous nucleus pulposus transplantation model(transverse process+mastoid process).