Neidlinger-Wilke Cornelia, Liedert Astrid, Wuertz Karin, Buser Zorica, Rinkler Christina, Käfer Wolfram, Ignatius Anita, Claes Lutz, Roberts Sally, Johnson W Eustace B
Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, Ulm, Germany.
Spine (Phila Pa 1976). 2009 Apr 1;34(7):663-9. doi: 10.1097/BRS.0b013e318194e20c.
The influence of mechanical load on pleiotrophin (PTM) and aggrecan expression by intervertebral disc (IVD) cells, and the effects of disc cell conditioned medium on endothelial cell migration was investigated.
To examine possible interactions of mechanical loads and known pro- and antiangiogenic factors, which may regulate disc angiogenesis during degeneration.
Pleiotrophin expression can be influenced by mechanical stimulation and has been associated with disc vascularization. Disc aggrecan inhibits endothelial cell migration, suggesting an antiangiogenic role. A possible interplay between these factors is unknown.
The influence of the respective predominant load (cyclic strain for anulus fibrosus and hydrostatic pressure for nucleus pulposus cells) on PTN and aggrecan expression by IVD cells was determined by real-time RT-PCR and Western blotting (PTN only). The effects of IVD cell conditioned medium on endothelial cell migration were analyzed in a bioassay using human microvascular endothelial (HMEC-1) cells.
Application of both mechanical loads resulted in significant alterations of gene expression of PTN (+67%, P = 0.004 in anulus cells; +29%, P = 0.03 in nucleus cells) and aggrecan (+42%, P = 0.03 in anulus cells, -25%, P = 0.03 in nucleus cells). These effects depended on the cell type, the applied load, and timescale. Conditioned media of nucleus pulposus cells enhanced HMEC-1 migration, but this effect was diminished after 2.5 MPa hydrostatic pressure, when aggrecan expression was diminished, but not 0.25 MPa, when expression levels were unchanged.
Mechanical loading influences PTN expression by human IVD cells. Conditioned media from nucleus pulposus cell cultures stimulated HMEC-1 endothelial cell migration. This study demonstrates that the influence of mechanical loads on vascularization of the human IVD is likely to be complex and does not correlate simply with altered expression of known pro- and antiangiogenic factors.
研究机械负荷对椎间盘（IVD）细胞中多效生长因子（PTM）和聚集蛋白聚糖表达的影响，以及椎间盘细胞条件培养基对内皮细胞迁移的作用。
探讨机械负荷与已知的促血管生成和抗血管生成因子之间可能存在的相互作用，这些因子可能在椎间盘退变过程中调节椎间盘血管生成。
多效生长因子的表达可受机械刺激影响，且与椎间盘血管化有关。椎间盘聚集蛋白聚糖可抑制内皮细胞迁移，提示其具有抗血管生成作用。这些因子之间可能存在的相互作用尚不清楚。
通过实时逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹法（仅检测PTN），确定各自主要负荷（纤维环的循环应变和髓核细胞的静水压力）对IVD细胞中PTN和聚集蛋白聚糖表达的影响。使用人微血管内皮（HMEC-1）细胞，通过生物测定法分析IVD细胞条件培养基对内皮细胞迁移的作用。
两种机械负荷的施加均导致PTN基因表达发生显著变化（纤维环细胞中增加67%，P = 0.004；髓核细胞中增加29%，P = 0.03）以及聚集蛋白聚糖表达发生显著变化（纤维环细胞中增加42%，P = 0.03；髓核细胞中减少25%，P = 0.03）。这些效应取决于细胞类型、施加的负荷和时间尺度。髓核细胞的条件培养基可增强HMEC-1迁移，但在2.5MPa静水压力下，当聚集蛋白聚糖表达减少时，这种作用减弱，而在0.25MPa时，表达水平未改变，作用未减弱。
机械负荷影响人IVD细胞中PTN的表达。髓核细胞培养的条件培养基可刺激HMEC-1内皮细胞迁移。本研究表明，机械负荷对人IVD血管化的影响可能很复杂，且与已知的促血管生成和抗血管生成因子表达的改变并非简单相关。
