Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Tissue Engineering Research, 639 Zhi Zao Ju Road, Shanghai 200011, PR China.
Biomaterials. 2011 Jun;32(17):4085-95. doi: 10.1016/j.biomaterials.2011.02.033. Epub 2011 Mar 12.
Previous studies have demonstrated the beneficial effect of mechanical loading on in vitro tendon engineering. To understand the mechanism, human tenocytes and polyglycolic acid long fibers were used for in vitro tendon engineering in a bioreactor system for 12 weeks with and without dynamic loading. The engineered neo-tendons were subjected to proteomic analysis using mass spectrometry along with shotgun strategy. As expected, mechanical loading resulted in a more mature tendon tissue characterized by a firmer tissue texture and densely deposited matrices which formed longitudinally aligned collagen fibers in a highly compact fashion. In contrast, non-loaded neo-tendon revealed loosely and less deposited matrices in a relatively less organized pattern. Proteins isolated from two groups of tissues exhibited similar distribution of isoeletric point and molecular weight indicating the similarity and comparability of the tissue specimens. Further, proteomic analysis showed that total 758 proteins were identified from both groups with 194 and 177 proteins uniquely presented in loaded and non-loaded tendons, respectively. Comparison of loaded and non-loaded tendons revealed 195 significantly up-regulated proteins and 189 significantly down-regulated proteins. The differentially expressed proteins could generally be classified into the categories of extracellular matrix, intra-cellular signaling, cytoskeleton and inflammatory response. Among them, significantly up-regulated collagens I and VI, MMP-14, WNT5A, microfilament molecules and some inflammatory factors suggest that the possible mechanism for this particular biological phenomenon may involve increased production of tendon specific matrices, enhanced cross-link of collagens and other matrix molecules, proper matrix remodeling for tissue maturation and mechanotransduction (including non-canonical Wnt signal pathway) mediated other biological processes.
先前的研究已经证明了机械加载对体外肌腱工程的有益效果。为了了解其机制，使用人肌腱细胞和聚乙二醇酸长纤维在生物反应器系统中进行了 12 周的体外肌腱工程，其中包括有和没有动态加载的情况。使用质谱法和鸟枪法对工程化的新肌腱进行了蛋白质组学分析。正如预期的那样，机械加载导致更成熟的肌腱组织，其特征是组织质地更坚硬，基质更密集，形成纵向排列的胶原纤维，排列非常紧密。相比之下，未加载的新肌腱显示出基质疏松、沉积较少，排列相对较不规整。从两组组织中分离出的蛋白质表现出相似的等电点和分子量分布，表明组织标本的相似性和可比较性。此外，蛋白质组学分析表明，从两组组织中总共鉴定出 758 种蛋白质，其中加载和未加载肌腱分别有 194 种和 177 种蛋白质是独特存在的。加载和未加载肌腱的比较显示，有 195 种蛋白质显著上调，189 种蛋白质显著下调。差异表达的蛋白质通常可以分为细胞外基质、细胞内信号转导、细胞骨架和炎症反应等类别。其中，显著上调的胶原蛋白 I 和 VI、MMP-14、WNT5A、微丝分子和一些炎症因子表明，这种特定生物学现象的可能机制可能涉及增加肌腱特异性基质的产生、增强胶原蛋白和其他基质分子的交联、适当的基质重塑以促进组织成熟和机械转导（包括非经典 Wnt 信号通路）介导的其他生物学过程。
