Manipulation of stem cell differentiation by noninvasive electrical stimulus

描述（由申请人提供）：使用干细胞的潜在治疗需要阐明控制干细胞更新和分化的机制。诱导干细胞分化为组织特异性谱系的操作技术必须得到开发和测试。然后可以设想用于组织工程的基于干细胞的技术。然而，要实现这一目标，首先需要了解和应用工程原理，整合生物和物理信号，放大分子信号机制，以促进和增强干细胞的选择性增殖和分化。我们最近首次证明了使用非侵入性电刺激可以用于操纵间充质干细胞（MSC）分化。虽然电刺激在过去已被有效地用于诱导多种细胞和分子反应，但电刺激的使用既没有得到优化，也没有探索调节人间充质干细胞分化的电偶联机制。因此，我们建议结合独特的、新颖的物理和光学技术来：(1)优化促进hMSC成骨分化的电刺激参数；(2)阐明整合素介导的信号通路的作用，包括丝裂原激活的蛋白激酶信号传导机制。我们建议使用量子点共轭整合素来确定人间充质干细胞表面整合素动力学的变化，并将其与成骨分化不同阶段整合素的下调联系起来。假设和至少2种替代的电偶联机制提出了基于整合素重新分配和聚集响应电刺激。电刺激的最佳应用和电偶联机制的阐明将为一种新的生物技术方法来操纵干细胞分化奠定基础，为建立一个整合物理和分子技术的组织工程方法的新范例铺平道路。长期的研究目标将包括通过最佳使用物理刺激来操纵和控制干细胞的增殖和分化，从而调节干细胞衍生的工程组织结构的完整性和功能。

DESCRIPTION (provided by applicant): Potential therapeutic treatment using stem cells requires elucidation of mechanisms that control stem cell renewal and differentiation. Manipulation techniques to induce stem cell differentiation into tissue-specific lineages will have to be developed and tested. Stem cell-based technologies for tissue engineering can then be envisioned. However, achievement of such goals would first require the knowledge and application of engineering principles to integrate biological and physical signals and amplify the molecular signaling mechanism(s) in order to promote and enhance selective stem cell proliferation and differentiation. We have recently demonstrated for the first time that use of non-invasive electrical stimulus can be applied to manipulate mesenchymal stem cell (MSC) differentiation. Although electrical stimulus has been used beneficially in the past to induce diverse cellular and molecular responses, neither the use of electrical stimulus has been optimized nor have the electrocoupling mechanisms regulating human MSC differentiation have been explored. We therefore propose to combine unique, novel physical and optical techniques to (1) optimize the electrical stimulus parameters for facilitated hMSC osteogenic differentiation and (2) elucidate the role of integrin-mediated signaling pathways, including the mitogen-activated protein kinase signaling mechanisms. We propose to use quantum dot-conjugated integrins to determine changes in the integrin dynamics on the human MSC surface and correlate them with integrin down-regulation at the different stages of osteogenic differentiation. Hypotheses and at least 2 alternate electrocoupling mechanisms are proposed based on integrin redistribution and clustering in response to electrical stimulus. Optimal application of electrical stimulus and elucidation of electrocoupling mechanisms will lay the foundation for a novel biotechnology approach to manipulate stem cell differentiation, paving the way to establish a new paradigm for tissue engineering methodologies that integrates physical and molecular techniques. The long- term research objectives would include manipulation and control of stem cell proliferation and differentiation by the optimal use of physical stimuli and, thereby, regulate the integrity and functionality of stem cell-derived engineered tissue constructs.