Intercellular Communications in Hepatic Function

肝功能中的细胞间通讯

• 批准号: 7126093
• 负责人: SANGEETA N. BHATIA
• 金额: $ 28.94万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-20 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7126093
• 关键词: bioengineering /biomedical engineering; biomedical equipment development; biomimetics; bioreactors; biotechnology; cadherins; cell cell interaction; cell differentiation; fibroblasts; fluid flow; gap junctions; gene expression; high throughput technology; laboratory rat; liver cells; liver function; mixed tissue /cell culture; model design /development; physical model; tissue engineering

DESCRIPTION (provided by applicant): This project focuses on development and characterization of an in vitro model of hepatic tissue by control of cell-cell interactions. The difficulty in sustaining differentiated hepatocyte functions in vitro has negatively impacted progress towards cell-based therapies for liver disease as well as in vitro experimentation (e.g. drug toxicity studies). It is proposed that an integrated 'biomimetic' platform incorporating key hepatic features (differentiated hepatocytes, compartmentalized metabolism, oriented cell-cell interactions, and directional fluid flow) will serve as a better predictive platform than existing models for Xenobiotic metabolism and physiological experimentation. Preliminary data suggest that co-cultivation of hepatocytes with non-parenchymal cells (fibroblasts) results in long-term differentiated functions, though neither the molecular basis for the 'co-culture effect' nor the dynamics of the process are well understood. In the proposed research, we aim to characterize the dynamics of the co-culture response, uncover the mechanisms that underlie the co-culture response, and incorporate the required elements in a microfabricated array of bioreactors that mimics features of the liver in a high-throughput platform. Specific Aim 1 will be to investigate the dynamic role of homotypic hepatocyte/hepatocyte) gap junction communication and heterotypic (hepatocyte/fibroblast) contact on differentiated functions. The investigator has developed a micropatterning tool that enables control of cell-cell interactions. Electroactive micropatterned surfaces will be utilized to dynamically release fibroblasts from co-culture and study the impact on hepatic function. The mechanism of the 'co-culture effect' was investigated previously using gene expression profiling of various fibroblast strains. Preliminary results indicate that cadherins may play a role in heterotypic signaling. Specific Aim 2 will be to investigate the role of cadherins in coculture, in particular T-cadherin, a candidate that was differentially expressed by over 30-fold. Preliminary results indicate that compartmentalized functions of the liver can be recreated in vitro using controlled oxygen gradients. Specific Aim 3 will be to combine oxygen gradients and directional fluid flow with differentiated hepatocytes (as determined in SA1 & 2) into an array of miniaturized bioreactors that can be used as predictive models of the liver. The engineered tissue will be assessed by examining the responses to well-characterized stimuli. This project will lead to an integrated understanding of how cell-cell interactions produce coordinated organ function and will establish a robust predictive model of liver function for pharmaceutical drug development and fundamental hepatic studies.

描述(由申请人提供)： 本项目致力于通过控制细胞与细胞之间的相互作用来开发和表征肝组织的体外模型。在体外维持分化的肝细胞功能的困难已经对肝病的基于细胞的治疗以及体外实验(例如药物毒性研究)的进展产生了负面影响。有人提出，一个整合了肝脏关键特征(分化的肝细胞、分区的新陈代谢、定向的细胞-细胞相互作用和定向的液体流动)的综合仿生平台将成为比现有的异种生物代谢和生理实验模型更好的预测平台。初步数据表明，肝细胞与非实质细胞(成纤维细胞)共培养会导致长期的分化功能，尽管这种共培养效应的分子基础和过程的动力学都不是很清楚。在拟议的研究中，我们的目标是表征共培养反应的动力学，揭示共培养反应背后的机制，并在高通量平台上模拟肝脏特征的微型制造的生物反应器阵列中整合所需的元素。具体目标1将研究同型肝细胞/肝细胞缝隙连接通讯和异型(肝细胞/成纤维细胞)接触在分化功能中的动态作用。这位研究人员已经开发出一种微图案化工具，可以控制细胞与细胞的相互作用。电活性微图案化表面将被用来动态释放共培养的成纤维细胞，并研究其对肝功能的影响。在此之前，我们曾用不同的成纤维细胞株的基因表达谱来研究这种“共培养效应”的机制。初步结果表明，钙粘附素可能在异型信号转导中发挥作用。具体目标2将是研究钙粘附素在共培养中的作用，特别是T-钙粘附素，一个差异表达超过30倍的候选基因。初步结果表明，使用可控的氧气梯度，可以在体外重建肝脏的分区功能。具体目标3将是将氧气梯度和定向液体流动与分化的肝细胞(如SA1和2中所确定的)结合在一起，形成一系列可用作肝脏预测模型的微型生物反应器。工程组织将通过检测对特征明确的刺激的反应来进行评估。该项目将导致对细胞-细胞相互作用如何产生协调的器官功能的综合理解，并将为药物开发和基础肝脏研究建立一个强大的肝功能预测模型。