Cell and matrix response of temporomandibular cartilage to mechanical loading.
Cell and matrix response of temporomandibular cartilage to mechanical loading.
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颞下颌软骨对机械负荷的细胞和基质响应。
DOI：
10.1016/j.joca.2015.08.010
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发表时间：
2016-02
影响因子：
7
通讯作者：
Rowe DW
中科院分区：
文献类型：
--
作者：
Utreja A;Dyment NA;Yadav S;Villa MM;Li Y;Jiang X;Nanda R;Rowe DW
表达绿色荧光蛋白（GFP）的转基因小鼠的产生极大地帮助了我们了解骨和软骨等结缔组织的发育。生物系统（例如颞下颌关节（TMJ））在其适应性重塑能力范围内的扰动对于分析细胞谱系进展特别有用。本研究的目的是确定：(i) TMJ 中表达的 GFP 报告基因是否表明纤维软骨细胞成熟的不同阶段，以及 (ii) 机械负荷如何影响软骨不同区域的细胞反应。使用携带荧光报告基因组合（Dkk3-eGFP、Col1a1(3.6kb)-GFPcyan、Col1a1(3.6kb)-GFPtpz、Col2a1-GFPcyan 和 Col10a1-RFPcherry）的 4 周大转基因小鼠来分析下颌髁软骨中转基因的表达模式。为了研究颞下颌关节负荷的影响，使用定制弹簧对动物强制张口，每天施加 50 克力，持续 1 小时，持续 5 天。在负荷小鼠与对照小鼠中评估动态矿化和细胞增殖（EdU 标记）。下颌髁软骨浅表区表达Dkk3，软骨区Col1表达，肥大前期Col2表达，潮线及以下肥大区Col10表达。 TMJ 负载增加了软骨中 GFP 报告基因的表达和 EdU 标记的细胞，导致软骨所有层的厚度增加。此外，矿物质并置增加，导致潮位线以上未矿化细胞表达 Col10。颞下颌关节通过适应性重塑形成更厚的软骨来响应静态载荷。
The generation of transgenic mice expressing green fluorescent proteins (GFPs) has greatly aided our understanding of the development of connective tissues such as bone and cartilage. Perturbation of a biological system such as the temporomandibular joint (TMJ) within its adaptive remodeling capacity is particularly useful in analyzing cellular lineage progression. The objectives of this study were to determine: (i) if GFP reporters expressed in the TMJ indicate the different stages of cell maturation in fibrocartilage and (ii) how mechanical loading affects cellular response in different regions of the cartilage. Four-week-old transgenic mice harboring combinations of fluorescent reporters (Dkk3-eGFP, Col1a1(3.6kb)-GFPcyan, Col1a1(3.6kb)-GFPtpz, Col2a1-GFPcyan, and Col10a1-RFPcherry) were used to analyze the expression pattern of transgenes in the mandibular condylar cartilage. To study the effect of TMJ loading, animals were subjected to forced mouth opening with custom springs exerting 50 grams force for 1 hour/day for 5 days. Dynamic mineralization and cellular proliferation (EdU-labeling) were assessed in loaded vs control mice. Dkk3 expression was seen in the superficial zone of the mandibular condylar cartilage, followed by Col1 in the cartilage zone, Col2 in the prehypertrophic zone, and Col10 expression hypertrophic zone at and below the tidemark. TMJ loading increased expression of the GFP reporters and EdU-labeling of cells in the cartilage, resulting in a thickness increase of all layers of the cartilage. In addition, mineral apposition increased resulting in Col10 expression by unmineralized cells above the tidemark. The TMJ responded to static loading by forming thicker cartilage through adaptive remodeling.