Dynamical Processes in Cells and Tissues
Channel: ICTP Quantitative Life Sciences
Date: 2021-01-26

Speaker: Jonathan E. Dawson (University of Rostock, Germany)


Abstract: I will present two examples of dynamics and self-organization in living systems. Differentiation of adult stem cells into specialised cells plays a very important role in tissue regeneration and wound healing. Bone healing is a highly complex and tightly regulated physiological process that involves proliferation of human mesenchymal stem cells and osteogenic differentiation of human mesenchymal stem cells into osteoblasts (bone cells). In vitro osteoinduction via external electric field is a promising approach to build implants for bone regeneration. I will present a general mean-field theoretical framework that takes into account processes at the scale of a single cell and describes the dynamics of a stem cell population [1]. The theory is tested with in vitro experiments involving electrical stimulation of human mesenchymal stem cells. The analysis shows that proliferation rate is cell density-dependent and that electric field influences only osteogenic differentiation. At the tissue level, leaf vein morphogenesis and patterning involves cell shape changes ,and, is under the regulation of plant growth hormone auxin. How auxin coordinates the developmental regulation of leaf vein is not well understood. I will present a cell based model that captures the interplay between key biochemical processes and cell mechanics and describes early stages of mid-vein development in a growing leaf primordia [2]. Comparison of the model with experiments shows that the formation of early vein patterns may essentially be described in terms of auxin biosynthesis, its transport, and growth-dependent mechanical feedback from surrounding tissues.