TNTs参与网络式力学调控在BMSCs成骨向分化中的模型验证及机制探讨

The newly direction of bone regenerative medcine is osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) regulated by mechanical stress. In micro strain analysis of autograft reconstruction previously, our group found that the stress in the fillarea of BMSCs was diverted and the long term differentiate efficiency would be affected. Aim to solve the problem above, the mechanical loading device in heterogeneous and high gradient magnetic field in vitro had been prepared in preliminary experiment. We directly regulated the BMSCs differentiation with the magnetic beads' loading contorlled technique., and we concluded that the efficiency of osteogenic differentiation was greatly increased. Next, combined with the mechanical structure and geometry features of tunneling nanotubes (TNTs), a structural ideal will be assumed as a structural model of biomechanical network. This experiment is designed as following: firstly, parts of BMSCs will be combined with the immuno-magnetic beads bingding anti-β1 integrin antibody, then RNAi technique will be applied to interfere the formation of TNTs and cadherin. Subsequently, all of BMSCs will be loaded with magnetic force. Finally, the variation of unloaded celluar morphology will be observed by scanning electron microscopy, the expression of osteogenic differentiate markers will be identified. The aim of the validation aboved is to clarify the TNTs involved in the model mechanism of network-based synergism. Thereby, a new idea in bone regenerative medcine of BMSCs’ osteogenic differentiation regulated by mechanics will be provided.

机械力调控骨髓间充质细胞（BMSCs）成骨向诱导分化是骨再生医学领域的新方向。本课题组前期在对自体移植骨重建的微应变分析中发现BMSCs填充区的应力刺激被分流，这将成为影响其远期分化效率的因素。本研究为解决该问题，前期实验已制备出非均匀高梯度离体细胞磁场力学加载装置，依托磁珠接触式可控加载的技术手段直接对BMSCs的分化进行机械力调控，发现其成骨向分化的效率被大大提高。下一步拟结合隧道纳米管（TNTs）的力学结构及几何学特性，依照不同尺度设想并构建出力学网络调控的结构模型。用含抗β1整合素抗体的免疫磁珠与部分BMSCs结合，并利用RNAi技术分别影响TNTs与钙粘蛋白的形成，再通过磁力加载与普通BMSCs混合生长后的细胞群，依据未加载细胞形态结构的改变、成骨分化标志物作为验证手段，以期阐明TNTs参与网络式力学调控的模型机理，为骨再生医学中BMSCs力学诱导成骨向分化的研究提供新思路。

机械力调控骨髓间充质细胞（BMSCs）成骨向诱导分化是骨再生医学领域的新方向。本课题组前期在对自体移植骨重建的微应变分析中发现BMSCs填充区的应力刺激被分流，这将成为影响其远期分化效率的因素。本研究为解决该问题，前期进行了BMSCS体系建设与磁力加载干预，但是效果不佳，故改用C2C12细胞系，直接对机械力影响的基因进行研究。在本期研究中，我们通过检索筛选出肌肉系统受机械力刺激影响的基因，然后检测这些受到机械力影响的基因在肌肉分化中的表达变化，发现ALDH2和Hsc70可能介导机械力促进的肌肉再生，通过对这两个基因的敲减后再刺激分化后，最终发现了机械力刺激可以通过促进ALDH2和Hsc70的表达，进一步促进YY1的表达，而达到肌肉再生的目的。