Bioengineering approaches to map mechanotransduction in the living cell

项目总结/摘要 越来越明显的是，可溶性因子介导的化学信号传导和物理力介导的 机械传导在活细胞和组织中起关键作用。但我们对力如何作用 调节基因表达和重要的生物功能。位于或靠近细胞表面的机械传感器， 整合素、talin或黏着斑蛋白已经被报道，但是细胞核本身及其染色质是否可以作为一种整合素， 机械传感器是机械生物学领域的一个未回答的问题。然而，基因表达的调控， 正常细胞和癌细胞之间的相互作用是控制细胞功能和行为的最关键过程之一。 该研究项目旨在了解力和机械微环境如何直接影响基因 表达，并确定核内蛋白，负责介导力转移从核 活细胞中染色质的层与层相关区域。我们的初步结果强烈表明， 通过整合素的局部生理相关力可以通过拉伸 活细胞中的染色质。基于这些结果，我们提出了3个具体的目标，以阐明机械转导 活细胞中的机制。目的1：检验染色质拉伸是直接的细胞分裂所必需的假设。 通过整合素的强制转录上调;目的2：检验强制通过整合素直接上调转录的假设。 激活机械敏感基因多于持家基因DHFR;目的3：剖析机械敏感基因的机制 在高强度的外力和坚硬的基质上基因的抑制。我们的实验设计是严格的， 产生有洞察力的发现的可能性非常高。长期目标是制定新的战略， 干预调节动物和人类受试者活细胞中基因表达的过程， 治疗恶性肿瘤等疾病。

Project Summary/Abstract It is increasingly evident that both soluble factor-mediated chemical signaling and physical force-mediated mechanotransduction play critical roles in living cells and tissues. Yet we know relatively little about how force regulates gene expression and vital biological functions. Mechanosensors at or near the cell surface such as integrin, talin, or vinculin have been reported, but whether the nucleus itself and its chromatin can act as a mechanosensor is an unanswered question in the field of mechanobiology. Yet regulation of gene expression in normal cells and cancer cells is one of the most critical processes that control cellular functions and behaviors. This research project aims to understand how forces and mechanical microenvironment directly influence gene expression and to identify intra-nuclear proteins that are responsible for mediating force transfer from nuclear lamina to lamina-associated domains of chromatin in living cells. Our preliminary results strongly suggest that a local physiologically-relevant force via integrins can directly upregulation transcription via stretching the chromatin in living cells. Built on these results, we propose 3 specific aims to elucidate mechanotransduction mechanisms in the living cells. Aim 1: to test the hypothesis that chromatin stretching is required for direct transcription upregulation by force via integrins; Aim 2: to test the hypothesis that force via integrins directly activates mechanosensitive genes more than housekeeping gene DHFR; Aim 3: to dissect out the mechanism of gene repression in response to high forces and on stiff matrices. Our experimental designs are rigorous and the likelihood of generating insightful discovery is very high. The long-term goal is to develop novel strategies to intervene the processes that regulate gene expression in living cells in animals and human subjects to treat and cure diseases like malignant tumors.