Department of Orthopedics and Trauma Surgery, University Medical Center Freiburg, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany.
AO Research Institute Davos, Davos, Switzerland.
J Tissue Eng Regen Med. 2018 Apr;12(4):e2051-e2061. doi: 10.1002/term.2636. Epub 2018 Feb 6.
The aim of this study was to compare the effect of different disease initiators of degenerative disc disease (DDD) within an intervertebral disc (IVD) organ culture system and to understand the interplay between inflammation and degeneration in the early stage of DDD. Bovine caudal IVDs were cultured within a bioreactor for up to 11 days. Control group was cultured under physiological loading (0.02-0.2 MPa; 0.2 Hz; 2 hr/day) and high glucose (4.5 g/L) medium. Detrimental loading (0.32-0.5 MPa, 5 Hz; 2 hr/day) and low glucose (2 g/L) medium were applied to mimic the condition of abnormal mechanical stress and limited nutrition supply. Tumour necrosis factor alpha (TNF-α) was injected into the nucleus pulposus (100 ng per IVD) as a proinflammatory trigger. TNF-α combined with detrimental loading and low glucose medium up-regulated interleukin 1β (IL-1β), IL-6, and IL-8 gene expression in disc tissue, nitric oxide, and IL-8 release from IVD, which indicate a proinflammatory effect. The combined initiators up-regulated matrix metalloproteinase 1 gene expression, down-regulated gene expression of Type I collagen in annulus fibrosus and Type II collagen in nucleus pulposus, and reduced the cell viability. Furthermore, the combined initiators induced a degradative effect, as indicated by markedly higher glycosaminoglycan release into conditioned medium. The combination of detrimental dynamic loading, nutrient deficiency, and TNF-α intradiscal injection can synergistically simulate the proinflammatory and degenerative disease condition within DDD. This model will be of high interest to screen therapeutic agents in further preclinical studies for early intervention and treatment of DDD.
本研究旨在比较不同退行性椎间盘疾病（DDD）启动因子在椎间盘（IVD）器官培养系统中的作用，并了解 DDD 早期炎症和退变之间的相互作用。牛尾状 IVD 在生物反应器中培养长达 11 天。对照组在生理负荷（0.02-0.2 MPa；0.2 Hz；每天 2 小时）和高葡萄糖（4.5 g/L）培养基中培养。施加有害载荷（0.32-0.5 MPa，5 Hz；每天 2 小时）和低糖（2 g/L）培养基模拟异常机械应力和有限营养供应的条件。肿瘤坏死因子-α（TNF-α）被注入髓核（每个 IVD 100ng）作为促炎触发物。TNF-α与有害载荷和低葡萄糖培养基联合上调椎间盘组织中白细胞介素 1β（IL-1β）、IL-6 和 IL-8 的基因表达，从 IVD 中释放一氧化氮和 IL-8，表明具有促炎作用。联合启动子上调基质金属蛋白酶 1 基因表达，下调纤维环中 I 型胶原和核髓中 II 型胶原的基因表达，并降低细胞活力。此外，联合启动子诱导了降解作用，表现为糖胺聚糖明显更多地释放到条件培养基中。有害动态载荷、营养缺乏和 TNF-α 椎间盘内注射的组合可以协同模拟 DDD 中的促炎和退行性疾病状态。该模型将对筛选早期干预和治疗 DDD 的治疗剂具有重要意义。
