Deletion of Opg Leads to Increased Neovascularization and Expression of Inflammatory Cytokines in the Lumbar Intervertebral Disc of Mice
Deletion of Opg Leads to Increased Neovascularization and Expression of Inflammatory Cytokines in the Lumbar Intervertebral Disc of Mice
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Opg 缺失导致小鼠腰椎间盘新血管形成和炎症细胞因子表达增加
DOI：
10.1097/brs.0000000000001701
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发表时间：
2017-01-01
期刊：
影响因子：
3
通讯作者：
Shu, Bing
中科院分区：
文献类型：
--
作者：
Li, Xiao-Feng;Xue, Chun-Chun;Shu, Bing
研究设计。在显示椎间盘（IVD）退变的骨保护素（Opg）敲除（KO）小鼠中检查新血管形成和炎性细胞因子的表达。 目的。本研究的目的是阐明Opg KO小鼠腰椎IVD变性的病理变化。背景数据摘要。骨质疏松症是 IVD 退化的一个有争议的危险因素。 Opg 的缺失导致小鼠 IVD 变性。新血管形成和炎症细胞因子是IVD变性的关键因素。方法。 Opg KO 小鼠及其野生型（WT）同窝小鼠被安乐死。收获腰椎 IVD。番红O/固绿染色观察病理变化。进行显微计算机断层扫描 (micro-CT) 分析以确定腰椎 IVD 软骨和椎骨交界处的结构变化。进行抗酒石酸酸性磷酸酶（TRAP）染色以评估破骨细胞的形成。通过免疫组织化学 (IHC) 检测分析血管内皮生长因子 A (VEGF-A)、CD31、VE-钙粘蛋白、CD 34、白细胞介素 1 β (IL-1 β) 和肿瘤坏死因子 α (TNF-α) 的蛋白表达。通过实时聚合酶链反应（RT-PCR）分析IL-1β、IL-6和TNF-α的基因表达。结果。在12周龄的Opg KO小鼠中，腰椎IVD的终板软骨中形成了新骨，这在24周龄的Opg KO小鼠中变得更加明显。三维 (3D) mu CT 重建分析显示，L4 和 L5 椎骨的边缘凹凸不平，其中有骨髓腔。 Opg KO 小鼠腰椎 IVD 终板和生长板中 VEGF-A、CD31、VE-cadherin 和 CD34 的蛋白表达增加。 Opg KO小鼠腰椎IVD中IL-1β、IL-6和TNF-α的基因表达以及IL-1β和TNF-α的蛋白表达均呈高表达。结论。 Opg 敲除导致 Opg KO 小鼠腰椎间盘新生血管形成和炎性细胞因子表达增加，这可能在 IVD 变性中发挥重要作用。
Study Design. Neovascularization and expression of inflammatory cytokines were examined in Osteoprotegerin (Opg) knockout (KO) mice that show intervertebral disc (IVD) degeneration.Objective. The aim of this study was to clarify the pathological changes in lumbar IVD degeneration in Opg KO mice.Summary of Background Data. Osteoporosis is a controversial risk factor for IVD degeneration. Deletion of Opg resulted in IVD degeneration in mice. Neovascularization and inflammatory cytokines are key factors in IVD degeneration.Methods. Opg KO mice and their wild-type (WT) littermates were euthanized. Lumbar IVDs were harvested. Safranin O/Fast Green staining was performed to examine the pathological changes. Microcomputed tomographic (micro-CT) analysis was performed to determine the structural changes at the junction of lumbar IVD cartilage and vertebrae. Tartrate-resistant acid phosphatase (TRAP) staining was performed to evaluate osteoclast formation. Protein expression of vascular endothelial growth factor A (VEGF-A), CD31, VE-cadherin, CD 34, interleukin-1 beta (IL-1 beta), and tumor necrosis factors alpha (TNF-alpha) were analyzed by immunohistochemistry (IHC) assays. Gene expressions of IL-1 beta, IL-6, and TNF-alpha were analyzed by real-time polymerase chain reaction (RT-PCR).Results. In 12-week-old Opg KO mice, new bone was formed in the endplate cartilage of lumbar IVDs and this became more obvious in 24-week-old Opg KO mice. Three-dimensional (3D) mu CT reconstruction analyses showed that the edges of the L4 and L5 vertebrae were rugged with bone marrow cavities in it. Protein expression of VEGF-A, CD31, VE-cadherin, and CD34 was increased in the endplate and growth plate of lumbar IVDs of Opg KO mice. Gene expression of IL-1 beta, IL-6, and TNF-alpha as well as protein expression of IL-1 beta and TNF-alpha were highly expressed in the lumbar IVDs of Opg KO mice.Conclusion. Deletion of Opg leads to increased neovascularization and expression of inflammatory cytokines in the lumbar disc in Opg KO mice, which may play important roles in IVD degeneration.