慢性颈脊髓压迫症大鼠髓内基膜超微结构变化及其与MMP-9表达的相关性

发布时间：2018-03-28 01:32

本文选题：基膜　切入点：慢性脊髓压迫　出处：《中国脊柱脊髓杂志》2016年02期

【摘要】：目的 :观察慢性颈脊髓压迫症大鼠模型髓内基膜(basement membrane,BM)、基膜与星形细胞接触面(basement membrane-astrocyte contacts,BM-AC)的超微结构变化,并探讨其与基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)表达的相关性。方法 :72只雄性SD大鼠随机分为对照组(n=36)和实验组(n=36),对照组仅切除C5左侧椎板;实验组在切除C5左侧椎板后将吸水可膨胀聚氨酯薄板置入C6水平左侧椎板下硬膜外,建立慢性颈脊髓压迫模型,应用BBB(Basso Beattie Bresnahan)评分评价大鼠脊髓神经功能,并分别于造模后1d、14d、21d、28d、42d、70d取C5~C6段脊髓组织制备标本,用HE染色观察脊髓形态学变化、用MMP-9免疫组化染色检测脊髓MMP-9表达量,用透射电镜观察脊髓BM及BM-AC的变化。结果:对照组各时间点间BBB评分和实验组造模后1d的BBB评分无显著性差异,实验组造模后14d~70d的5个时间点BBB评分均显著性低于同时间点对照组(P0.05)。HE染色显示对照组各时间点及实验组造模后1d的脊髓未见受压,脊髓形态结构正常;实验组造模后1d可见脊髓白质区轻度水肿;造模后14d脊髓受压变形,灰质区血管增生,灰质、白质水肿,神经元细胞核碎裂;造模后21d和28d损伤逐渐加重;造模后42d脊髓水肿减轻,髓内空泡化,前角大运动神经元数目减少、胞浆稀少、胞核萎缩,突触减少,神经纤维稀疏,髓鞘层变薄;造模后70d仍见白质区水肿、神经元细胞核碎裂,灶性胶质细胞增生等退行性变,神经元数目增多。MMP-9免疫组化显示对照组各时间点及实验组造模后1d、70d脊髓MMP-9均呈弱表达,实验组造模后14d呈较强表达,21d呈强表达,28d呈较强表达,42d呈中度表达。对照组各时间点及实验组压迫后1d的BM电子密度及BM-AC均正常,实验组造模后14d~28d BM电子密度、BM-AC比率与对照组比较显著性降低(P0.05);实验组造模后42d、70d两者较前升高(P0.05),但仍显著低于对照组水平(P0.05)。MMP-9表达与BM电子密度及BM-AC变化呈负相关,相关系数分别为-0.892(P0.001)和-0.664(P0.001)。结论:慢性颈脊髓压迫性损伤后早期髓内BM降解、BMAC分离,后期部分修复。MMP-9可能通过降解BM及BM-AC影响脊髓压迫后血脊髓屏障的完整性。
[Abstract]:Objective: to observe the ultrastructural changes of the intramedullary basement membrane membrane-astrocyte (BM-AC) in rats with chronic cervical spinal cord compression. Methods Seventy-two male Sprague-Dawley rats were randomly divided into control group (n = 36) and experimental group (n = 36). In the experimental group, the water-absorbing expandable polyurethane thin plate was placed into the subdural space of the C6 level, and the chronic cervical spinal cord compression model was established. The spinal cord nerve function was evaluated by BBB(Basso Beattie Bresnahan score. The spinal cord tissue of the C5~C6 segment was taken from the spinal cord on the 1st day, 14d, 21d, 28d and 42d, respectively. The morphological changes of the spinal cord were observed by HE staining, and the expression of MMP-9 in the spinal cord was detected by MMP-9 immunohistochemical staining. The changes of BM and BM-AC in spinal cord were observed by transmission electron microscope. Results: there was no significant difference in BBB score between the control group and the BBB score of the experimental group at 1 day after modeling. The BBB scores of 14d~70d at 5 time points in the experimental group were significantly lower than those in the control group at the same time point (P 0.05). He staining showed that the spinal cord of the control group and the experimental group had no compression at each time point and 1 day after the model making, and the morphology and structure of the spinal cord were normal. Mild edema in the white matter area of the spinal cord was observed in the experimental group on the 1st day after modeling, compression deformation of the spinal cord was observed on the 14th day after modeling, vascular proliferation, gray matter, white matter edema and nuclear fragmentation of the neurons in the gray matter area, and the injury increased gradually on the 21st and 28th days after the establishment of the model. The edema of spinal cord was alleviated 42 days later, the intramedullary vacuolation, the number of major motor neurons in the anterior horn decreased, the cytoplasm was scarce, the nucleus atrophy, the synapse decreased, the nerve fibers were sparse, the myelin sheath became thinner, and the edema of the white matter area was still observed 70 days after the model. The neuronal nucleus fragmentation, focal glial cell proliferation and other degenerative changes. The number of neurons increased. MMP-9 immunohistochemical staining showed that the spinal cord MMP-9 was weakly expressed at each time point in the control group and on the 70th day after modeling in the experimental group. The experimental group showed strong expression on the 14th day and the middle expression on the 28th day, and the BM electron density and BM-AC of the control group and the experimental group were normal at each time point and 1 day after compression. The BM-AC ratio of 14d~28d BM in the experimental group was significantly lower than that in the control group (P 0.05A), and the expression of BM-AC in the experimental group was significantly lower than that in the control group (P 0.05), but the expression of MMP-9 was negatively correlated with the changes of BM electron density and BM-AC. The correlation coefficients were -0.892g / P0.001) and -0.664m / P0.001respectively. Conclusion: BMAC separation of BM degradation in early stage after chronic cervical spinal cord compression injury, partial repair of MMP-9 may affect the integrity of blood-spinal cord barrier after spinal cord compression by degradation of BM and BM-AC.
【作者单位】：中山大学附属第一医院东院脊柱外科;中山大学附属第一医院东院神经外科;
【基金】：国家自然科学基金项目(编号:81450020) 广东省自然科学基金项目(编号:S2013010015778)
【分类号】：R744

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