Localization of extracellular matrix receptors on the chondrocyte primary cilium
Localization of extracellular matrix receptors on the chondrocyte primary cilium
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DOI：
10.1369/jhc.5a6866.2006
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发表时间：
2006-09-01
影响因子：
3.2
通讯作者：
Poole, C. Anthony
中科院分区：
文献类型：
--
作者：
McGlashan, Susan R.;Jensen, Cynthia G.;Poole, C. Anthony
在软骨细胞和其他结缔组织细胞中发现单个初级纤毛。我们以前已经表明，细胞外基质（ECM）大分子，如胶原纤维与软骨细胞初级纤毛密切相关，其接触点的特征在于电子不透明斑块，表明ECM和纤毛之间的直接联系。本研究检测软骨细胞初级纤毛上ECM分子受体的表达。用抗α和β整联蛋白、NG 2、CD 44和膜联蛋白V的抗体荧光标记鸡胚胸骨。用乙酰化α-微管蛋白抗体标记初级纤毛。ECM受体的表达进行了检查软骨细胞质膜和他们的初级纤毛使用免疫荧光和共聚焦显微镜。所有的受体检查表明，点状分布在质膜上。α 2、α 3和β 1整联蛋白和NG 2也存在于初级纤毛上，而膜联蛋白V和CD 44被排除在外。受体阳性纤毛的数量从NG 2的8/50到β 1整联蛋白的43/50不等。这是第一个研究，以证明表达的整合素和NG 2的软骨细胞初级纤毛。这些数据强烈表明，软骨细胞的初级纤毛有必要的机械作为mechanosensors，连接ECM细胞质细胞器负责基质的生产和分泌。
A single primary cilium is found in chondrocytes and other connective tissue cells. We have previously shown that extracellular matrix (ECM) macromolecules such as collagen fibers closely associate with chondrocyte primary cilia, and their points of contact are characterized by electron-opaque plaques suggesting a direct link between the ECM and the cilium. This study examines the expression of receptors for ECM molecules on chondrocyte primary cilia. Embryonic chick sterna were fluorescently labeled with antibodies against a and P integrins, NG2, CD44, and annexin V. Primary cilia were labeled using acetylated a-tubulin antibody. Expression of ECM receptors was examined on chondrocyte plasma membranes and their primary cilia using immunofluorescence and confocal microscopy. All receptors examined showed a punctate distribution on the plasma membrane. alpha 2, alpha 3, and beta 1 integrins and NG2 were also present on primary cilia, whereas annexin V and CD44 were excluded. The number of receptor-positive cilia varied from 8/50 for NG2 to 43/50 for beta 1 integrin. This is the first study to demonstrate the expression of integrins and NG2 on chondrocyte primary cilia. The data strongly suggest that chondrocyte primary cilia have the necessary machinery to act as mechanosensors, linking the ECM to cytoplasmic organelles responsible for matrix production and secretion.