The effects of TGF-β1 and IGF-I on the biomechanics and cytoskeleton of single chondrocytes
The effects of TGF-β1 and IGF-I on the biomechanics and cytoskeleton of single chondrocytes
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DOI：
10.1016/j.joca.2006.05.013
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发表时间：
2006-12-01
影响因子：
7
通讯作者：
Athanasiou, K. A.
中科院分区：
文献类型：
--
作者：
Leipzig, N. D.;Eleswarapu, S. V.;Athanasiou, K. A.
目的：确定机械力和生长因子如何介导单个软骨细胞的正常和病理过程，可以帮助制定修复和替换因损伤或疾病而破坏的关节软骨的策略。本研究检测了转化生长因子β 1方法将牛浅、中、深关节软骨细胞接种于组织块培养的塑料上，分别用TGF-β 1（5 ng/mL）、IGF-Ⅰ（5 ng/mL）、IGF（100 ng/mL），或TGF-β 1（5 ng/mL）+ IGF-I（100 ng/mL）的组合。单个软骨细胞从所有的治疗进行了单独的研究，使用粘弹性蠕变测试和染色罗丹明鬼笔环肽的F-肌动蛋白细胞骨架。最后，实时RT-PCR进行β-actin.Results：蠕变试验表明，所有的生长因子治疗硬化细胞。罗丹明鬼笔环肽染色的软骨细胞的图像分析显示，来自所有生长因子组的细胞具有比对照组显著更高的荧光，反映了蠕变测试结果。生长因子改变了细胞形态，因为暴露于生长因子的软骨细胞保持更圆，表现出更大的细胞高度，并且较少扩散。最后，实时RT-PCR显示生长因子暴露对β-肌动蛋白mRNA丰度没有显著影响。然而，β-肌动蛋白的表达不同地带，这表明该基因将是不适合作为PCR管家gene.Conclusions：这些结果表明，TGF-β 1和IGF-I增加F-肌动蛋白水平在单个软骨细胞导致硬化的细胞，但是，似乎没有直接的转录调节未聚合的β-肌动蛋白。这表明观察到的反应最有可能是由于生长因子受体和整合素/粘着斑复合物之间的信号传导串扰。(C)2006年国际骨关节炎研究学会。由爱思唯尔有限公司出版。保留所有权利。
Objective: Ascertaining how mechanical forces and growth factors mediate normal and pathologic processes in single chondrocytes can aid in developing strategies for the repair and replacement of articular cartilage destroyed by injury or disease. This study examined effects of transforming growth factor-beta 1 (TGF-beta 1) and insulin-like growth factor-I (IGF-I) on the biomechanics and cytoskeleton of single zonal chondrocytes.Method Superficial and middle/deep bovine articular chondrocytes were seeded on tissue culture treated plastic for 3 and 18 h and treated with TGF-beta 1 (5 ng/mL), IGF-I (100 ng/mL), or a combination of TGF-beta 1 (5 ng/mL) + IGF-I (100 ng/mL). Single chondrocytes from all treatments were individually studied using viscoelastic creep testing and stained with rhodamine phalloidin for the F-actin cytoskeleton. Lastly, real-time RT-PCR was performed for beta-actin.Results: Creep testing demonstrated that all growth factor treatments stiffened cells. Image analysis of rhodamine phalloidin stained chondrocytes showed that cells from all growth factor groups had significantly higher fluorescence than controls, mirroring creep testing results. Growth factors altered cell morphology, since chondrocytes exposed to growth factors remained more rounded, exhibited greater cell heights, and were less spread. Finally, real-time RT-PCR revealed no significant effect of growth factor exposure on beta-actin mRNA abundance. However, beta-actin expression varied zonally, suggesting that this gene would be unsuitable as a PCR housekeeping gene.Conclusions: These results indicate that TGF-beta 1 and IGF-I increase F-actin levels in single chondrocytes leading to stiffening of cells; however, there does not appear to be direct transcriptional regulation of unpolymerized beta-actin. This suggests that the observed response is most likely due to signaling cross-talk between growth factor receptors and integrin/focal adhesion complexes. (C) 2006 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.