终板下骨注射平阳霉素建立恒河猴缺血性椎间盘退变模型

Animal models of intervertebral disc degeneration play important roles in investigating the mechanism and treatment of this disease. Nowadays, many animal models had been constructed, however, the degenerations induced in these models were the consequence of an intermediate force exerted by outer factors, which were quite different to that happed in natural pathological process in human. In a previous study from our group, a lumbar intervertebral disc degenerative model of rabbit was constructed, which had some drawbacks in model establishment such as lack axial load. In this study, we inject pingyangmycin into vertebral bodies under cartilage endplate of Rhesus monkey to destroy its microcirculation and induce degeneration of cartilage endplate. Finally, the lumbar intervertebral disc degeneration appears. The feasibility and stability of this model are verified by hispathological and biochemical evidences. Magnetic resonance molecular imaging (T2 map value and T1ρ map value) were used to establishing early non-invasive diagnosis standard for intervertebral disc degenerations. In this model, the degeneration of lumbar intervertebral disk and cartilage endplate can be ascribed to malnutrition and axial load instead of effects from outer forces in other models, which are similar to that happed in human. The establishment of this model can lay a foundation to further study the mechanism of intervertebral disc degeneration and provide a good test platform for preclinical study of biomaterials. It supposed that this model are vital important for basic and clinical researches.

椎间盘退变动物模型在疾病发病机制和诊治研究中发挥了重要作用，目前报道的椎间盘退变动物模型主要是通过破坏椎间盘正常生物力学环境或椎间盘自身结构获得，与人类椎间盘退变的病程存在较大差异。我们曾制作兔椎间盘终板下骨缺血诱导椎间盘退变模型，因缺乏椎体轴向载荷作用力，该模型与人类发病过程有一定差距。本课题拟经皮穿刺恒河猴腰椎间盘终板下骨并注射平阳霉素，破坏终板下微循环，与轴向自然载荷力的共同作用下诱导腰椎间盘退变。采用MR分子成像技术动态量化评价其退变过程，并筛选恒河猴腰椎间盘自然退变的数据验证动物模型的相似度，采用组织病理学、生化检测验证动物模型的可靠性和稳定性以及胶原蛋白和蛋白聚糖变化与MR分子成像参数的关系，建立早期椎间盘退变的MR量化诊断标准。本项目将建立与人类椎间盘退变发展过程相接近的模型，为椎间盘退变的发病机制、分子治疗和再生修复研究提供理想的实验平台，具有重要的临床和科学意义。

随着分子生物学和材料医学的发展，椎间盘再生技术可达到恢复脊柱结构和生理功能的完整性，为椎间盘退变的早期防治带来了希望，然而，缺乏理想的临床前试验动物模型及其无创评价体系是阻碍其向临床过度的主要原因之一。本项目将首创一种新的恒河猴营养障碍腰椎间盘退变模型，这种模型比较接近人类椎间盘退变的病程，为椎间盘退变机制和再生修复的研究提供一种理想的动物模型。.项目研究内容包括：⑴恒河猴腰椎间盘自然退变的筛选及其椎间盘退变的相关数据建立；⑵构建恒河猴缺血性腰椎间盘退变动物模型；⑶恒河猴腰椎间盘早中期退变的磁共振T1ρ和T2-mapping评价体系构建。.项目研究结果包括：⑴恒河猴腰椎间盘髓核组织T1ρ驰豫时间值、T2-map驰豫时间值与Pfirrmann分级呈高度负相关，磁共振T1ρ和T2-mapping成像技术可以用于量化评价恒河猴腰椎间盘退变，T1ρ成像对恒河猴腰椎间盘早中期退变评价优于中晚期退变，T2-mapping成像对中晚期退变评价优于早中期退变。⑵恒河猴L1~3椎间盘较L6~S1椎间盘更容易发生退变。⑶年龄是恒河猴腰椎间盘自然退变的主要影响因素。⑷恒河猴腰椎间盘髓核组织蛋白聚糖含量与T1ρ值和T2-map值均呈高度正相关，但T1ρ值与蛋白聚糖含量的关系更为密切。T1ρ值预测恒河猴早中期腰椎间盘退变髓核组织蛋白聚糖含量的方程为：Y=1.247+5.523X(X>40.3ms)。⑸恒河猴腰椎间盘髓核组织胶原蛋白含量与T1ρ值和T2-map值均呈负相关，但T2-map值与胶原蛋白含量关系更加密切。T2-map值预测恒河猴中晚期腰椎间盘退变髓核组织胶原蛋白含量的方程为：Y=178.892-1.282X(X<76.8ms)。⑹组织病理学的HE形态学、CD34和MMP-1检测结果证实终板下骨注射平阳霉素可引起椎骨缺血和退变。⑺组织病理学的HE形态学和PAS检测结果证实终板下骨注射平阳霉素可引起软骨终板的退变。⑻磁共振T1ρ和T2-mapping成像随访结果结合软骨终板和终板下骨的检测结果，证明终板下骨注射平阳霉素可成功构建恒河猴营养障碍腰椎间盘退变模型，多次干预可使椎间盘退变进一步加重。.本项目研究结果证实了营养障碍可引起腰椎间盘退变的假说，为椎间盘再生技术的临床前试验提供一种理想的动物模型，建立了一套无创精确量化评价腰椎间盘退变的体系，具有十分重要的科学意义和临床价值。