Regional differences in cell shape and gap junction expression in rat Achilles tendon: relation to fibrocartilage differentiation
Regional differences in cell shape and gap junction expression in rat Achilles tendon: relation to fibrocartilage differentiation
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DOI：
10.1046/j.1469-7580.1998.19320215.x
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发表时间：
1998-08-01
影响因子：
2.4
通讯作者：
Gao, J
中科院分区：
文献类型：
--
作者：
Ralphs, JR;Benjamin, M;Gao, J
肌腱细胞具有复杂的形状，具有许多细胞突起，并与其细胞外基质中的胶原纤维束密切相关。当细胞和它们的突起彼此接触时，它们形成间隙连接。在本研究中，我们研究了大鼠跟腱表型不同区域的间隙连接成分的分布。该肌腱在其跟骨附着处包含一个突出的附着点纤维软骨和一个籽骨纤维软骨，籽骨纤维软骨紧靠附着点的近端压在跟骨上。使用DiI染色的研究表明，在纯肌腱的横切面上，典型的星状细胞形状，细胞撤回其细胞突起，并在纤维软骨区变圆。与形状的变化相一致，细胞停止表达差距连接蛋白连接蛋白32和43，连接蛋白43在过渡中比连接蛋白32更早消失。因此，在肌腱的表型不同的区域中，细胞相互交流的能力存在重大差异。单个纤维软骨细胞必须通过细胞/基质相互作用来感知细胞外基质的变化，但只能通过间接的细胞因子和生长因子信号传导来协调它们的行为。肌腱细胞有额外的可能性，除了上述，他们有可能通过间隙连接直接沟通细胞质信号。肌腱中纤维软骨的形成是由于压缩力和拉伸力的存在。可能是不同的系统被用于感知和响应纤维和软骨组织中的这种力。
Tendon cells have complex shapes, with many cell processes and an intimate association with collagen fibre bundles in their extracellular matrix. Where cells and their processes contact one another, they form gap junctions. In the present study, we have examined the distribution of gap junction components in phenotypically different regions of rat Achilles tendon. This tendon contains a prominent enthesial fibrocartilage at its calcaneal attachment and a sesamoid fibrocartilage where it is pressed against the calcaneus just proximal to the attachment. Studies using DiI staining demonstrated typical stellate cell shape in transverse sections of pure tendon, with cells withdrawing their cell processes and rounding up in the fibrocartilaginous zones. Coincident with change in shape, cells stopped expressing the gap junction proteins connexins 32 and 43, with connexin 43 disappearing earlier in the transition than connexin 32. Thus, there are major differences in the ability of cells to communicate with one another in the phenotypically distinct regions of tendon. Individual fibrocartilage cells must sense alterations in the extracellular matrix by cell/matrix interactions, but can only coordinate their behaviour via indirect cytokine and growth factor signalling. The tendon cells have additional possibilities-in addition to the above, they have the potential to communicate direct cytoplasmic signals via gap junctions. The formation of fibrocartilage in tendons occurs because of the presence of compressive as well as tensile forces. It may be that different systems are used to sense and respond to such forces in fibrous and cartilaginous tissues.