From the Physics of the Epithelial-Mesenchymal Transition to Cartilage Formation

点击翻译按钮获取中文摘要

Tissues perform a broad range of essential tasks in our body.They are responsible for the functionality of organs, allow to lift weights, process and conduct electric signals, and give shape to the body and the organs.The later task is accomplished by the class of connective tissues, which includescartilage as an example. In an adult organism, a major endeavor is to maintain the proper functionality of the exiting tissues. However, these tissues have to develop first during embryogenesis before they can fulfill their final purpose. In an embryo there is a special cell phenotype, the mesenchymal cell, which is involved in mostly all developmental processes. Together with epithelial cells, mesenchymes constitute the major cellular component in embryonic tissues.Moreover, they can reversibly transform to epithelial cells and differentiate to other cell phenotypes such as chondrocytes. The later, together with the extracellular material, makes up cartilage.So far the physical mechanisms are unknown, which govern the transition between epithelial and mesenchymal cells and the formation of cartilage from a mixture of both cell types.Additionally, related research mostly focuses on the involved chemical signals and often neglects the role of mechanical properties of the tissue.Recent experiments indicate that mechanical interactions between cells and changes of their physical properties are crucial for the cell-cell transitions and during the formation of cartilage. Thus I would like to develop a theoretical description for the transition of both cell types and extend it to describe how cartilage forms from of a mixture of epithelial and mesenchymal cells. To this end I would like to construct a simulation model and a continuous description to predict the composition, the mechanical properties and the degree of order of the tissue. All theoretical approaches should be scrutinized by corresponding experimental studies.Unravelling the physical principles, and dissecting the contributions of mechanical andbiochemical processes, which are involved in the reversible cell type transitions and the formation of cartilage, will help to improve our understanding on the development of complex tissues during embryogenesis.This knowledge could allow to efficiently control and guide cell Differentiation in tissue engineering which might pave the way to grow complex artificial tissues.