生物医学工程系学术报告6.2(报告人：Dr. Chia-Ching (Josh) Wu )
发布时间: 2010-06-01 02:59:00
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北京大学工学院 生物医学工程系学术报告
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报告一题目：Cross interaction of adhesion force and FAK signal on different substrate rigidity
报告二题目：Numerical simulation of 3D intracellular force distribution
报告人 Dr. Chia-Ching (Josh) Wu
Department of Cell Biology and Anatomy,
National Cheng Kung University, Taiwan
报告一内容摘要
Mechanical property of the microenvironment is important for cell growth and functional expression. Focal adhesion kinase, FAK, plays a key regulatory function for initiation of intracellular signals that trigger by cell adhesion between cell and extracellular matrix. To investigate the role of FAK in cell adhesion force on different rigidity of substrate, we plated Madin-Darby Canine Kidney (MDCK) epithelial cell on glass surface, 1kPa, and 30kPa polyacrylamide gels, respectively. Different expression levels of FAK by gene overexpression (FAK-WT), knock-out (FRNK), and as well as control vector are constitutively expressed to probe the function of FAK in rigidity sensing. The adhesion force management regulated by FAK expressions and rigidity sensing are measured by cytodetachment device. The results indicate that cell spreading area, adhesion force, and work for cell detachment are increased as MDCK cells growth on higher rigidity of substrate. Increase FAK expression can enhance cell spreading and normalized adhesion force on 30kPa and 1kPa gels in FAK-WT cells, but cannot override the effect provided by substrate rigidity. However, the affecting index analysis showed that FAK have bigger influence on soft substrate than stiff matrix. Therefore, the mechanical roles of FAK on softer substrate are revealed.
报告二内容摘要
Cytoskeleton, the major mechanical component of cells, supports cell body and dominates cell motility to assist cells in performing their biological functions. Previous researches have proposed various two-dimensional and three-dimensional “initial-round” cytoskeleton models to investigate the mechanical properties of cells. However, most cells in vivo behave after attachment with a spread state instead of in initial-round state without any interacting forces with surrounding environment during suspending situation. These spreading-related behaviors, such as transmigration and cancer metastasis, are difficult to simulate in computer modeling by an initial-round cytoskeleton model due to the limitations of boundary condition. Establishing an applicable cytoskeleton model with a certain degree of attachment is essential for the further studies. We have summarized several proposed cytoskeleton models, including the pre-stressed cable net, semi-flexible network, open-cell foam model, tensegrity and granular cell model, to evaluate their pros and cons as well as their potential for developing an efficient cytoskeleton model for the next step of cell spreading behaviors.
主持人：熊春阳 副教授
时间：6月2日（周三）上午9:30
地点：廖凯原楼2-401会议室
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