Disassembly of the vimentin cytoskeleton disrupts articular cartilage chondrocyte homeostasis
Disassembly of the vimentin cytoskeleton disrupts articular cartilage chondrocyte homeostasis
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DOI：
10.1016/j.matbio.2006.06.002
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发表时间：
2006-09-01
期刊：
影响因子：
6.9
通讯作者：
Duance, Victor C.
中科院分区：
文献类型：
--
作者：
Blain, Emma J.;Gilbert, Sophie J.;Duance, Victor C.
关节软骨的功能是分散施加在关节上的力。它包括主要含有胶原蛋白、蛋白聚糖和水的细胞外基质，以维持其功能特性，并散布有软骨细胞。软骨细胞骨架包括肌动蛋白微丝、微管蛋白微管和波形蛋白中间丝。先前的研究已经确定了肌动蛋白和微管蛋白在调节细胞外基质成分聚集蛋白聚糖和II型胶原蛋白的合成中的贡献。波形蛋白在任何细胞类型中对细胞外基质生物合成的贡献以前都没有得到解决。因此，本研究的目的是评估波形蛋白在软骨细胞代谢中的作用。波形蛋白中间丝在高密度单层关节软骨细胞培养物中使用丙烯酰胺破坏7天。通过向培养物中加入[H-3]-脯氨酸测量从头蛋白质和胶原合成，并通过向培养物中加入[S-35]-硫酸盐测量硫酸化糖胺聚糖（sGAG）合成。波形蛋白破坏导致胶原蛋白合成减少，而sGAG合成不受影响。此外，H型胶原蛋白和聚集蛋白聚糖基因转录显着减少，表明观察到的影响发生在转录和翻译水平。3天的冷追踪证明了对胶原和sGAG降解的显著抑制;胶原降解的减少通过观察到的pro-MMP 2表达和活化的减少来证实。我们已经证明，一个完整的波形蛋白中间丝网络有助于维持软骨细胞表型，因此有利于细丝分解的不平衡可能会干扰关节软骨的完整性，并可能最终导致病理学的发展，如骨关节炎。(c)2006年Elsevier B. V./国际矩阵生物学会。All rights reserved.
Articular cartilage functions in dissipating forces applied across joints. It comprises an extracellular matrix containing primarily collagens, proteoglycans and water to maintain its functional properties, and is interspersed with chondrocytes. The chondrocyte cytoskeleton comprises actin microfilaments, tubulin microtubules and vimentin intermediate filaments. Previous studies have determined the contribution of actin and tubulin in regulating the synthesis of the extracellular matrix components aggrecan and type II collagen. The contribution of vimentin to extracellular matrix biosynthesis in any cell type has not previously been addressed. Therefore the aim of this study was to assess the role of vimentin in cartilage chondrocyte metabolism. Vimentin intermediate filaments were disrupted in high-density monolayer articular chondrocyte cultures using acrylamide for 7 days. De novo protein and collagen synthesis were measured by adding [H-3]-proline, and sulphated glycosaminoglycan (sGAG) synthesis measured by adding [S-35]-sulphate to cultures. Vimentin disruption resulted in decreased collagen synthesis, whilst sGAG synthesis was unaffected. In addition, there was a significant reduction in type H collagen and aggrecan gene transcription suggesting that the effects observed occur at both the transcriptional and translational levels. A 3-day cold chase demonstrated a significant inhibition of collagen and sGAG degradation; the reduction in collagen degradation was corroborated by the observed reduction in both pro-MMP 2 expression and activation. We have demonstrated that an intact vimentin intermediate filament network contributes to the maintenance of the chondrocyte phenotype and thus an imbalance favouring filament disassembly can disturb the integrity of the articular cartilage, and may ultimately lead to the development of pathologies such as osteoarthritis. (c) 2006 Elsevier B.V./Intemational Society of Matrix Biology. All rights reserved.