通俗演講

2018/12/18(Tue)     14:00 -15:30    一樓演講廳1st Floor(auditorium)

Title

How to coordinate topology in living systems: a new biophysics perspective

Speaker

Dr. Chin-Lin Guo

Institute of Physics, Academia Sinica

Abstract

In our bodies, the topology of cells and tissues, i.e., how they are spatially distributed and how they partition signaling activity in the three-dimensional space, links tightly to biological functions. Failure of proper topology control leads to diseases such as organ degeneration and tumor progression. For decades, the dogma for topology control in living systems has been the interactions of diffusive chemicals. It is suggested that the dynamic instability of interacting chemicals can form spatiotemporal patterns to guide the assembly of intracellular cytoskeleton, the mechanical output of which, shapes cell and tissue topology, thereby determining cell fate and functional performance. Conversely, little is known about whether the topology can spontaneously emerge through the mechanical instability of cytoskeleton, and in turn patterns chemical signals. Here, we present two studies to show that multicellular coordination of topology can spontaneously emerge through steric hindrance of cytoskeleton in epithelial-mesenchymal transition (an important step in organogenesis, healing, and tumor invasion), and that apicobasal polarity (an essential element for organ development and tumor suppression) can de novo form from mechanical self-partitioning of cytoskeletal components before the onset of chemical patterning. Our results highlight not only a new biophysics perspective to organ homeostasis and regeneration, but also a potential paradigm-shifting strategy to suppress aberrant cell behavior such as malignancy.
在我們的身體中,細胞和組織的拓撲結構,即它們如何在三維空間上分佈以及形成化學信號,與生物功能緊密相關。拓撲結構控制的失敗會導致器官退化和腫瘤等各種疾病。一直以來,人們認為化學訊號是控制生命系統拓撲結構的主要機制,即化學反應指導細胞內細胞骨架的組裝及力學輸出,從而建立拓撲結構以及功能。而是否拓撲結構可以反向通過細胞骨架的力學不穩定性自發地出現,從而控制化學信號,則知之甚少。這裡,我們提出兩項研究,闡明多細胞協調的拓撲結構是可以通過細胞骨架在上皮 - 間質轉化中(一個在器官癒合和腫瘤侵襲的重要步驟)自發地出現,以及基頂極性(一種器官發育和腫瘤抑制的必要元素)是可以在化學訊號開始之前從細胞骨架的力學自分配中重新形成。我們的研究結果不僅指出了在器官功能和再生上一個新的生物物理學觀點,同時還指出抑制惡性腫瘤等異常細胞行為的一種可能性新方針。 (Poster) Download: http://real.sinica.edu.tw:8080/ramgen/phys/20181218-Chin-LinGuo.mp4