Arpita Upadhyaya, Professor, Department of Physics, Institute for Physical Science and Technology, Co-Director, Biophysics Program

Seminar title: "How cells respond to physical cues – the role of cytoskeletal dynamics"

Abstract:

Cells need to sense and adaptively respond to their physical environment in diverse biological contexts such as development, cancer and the immune response. In addition to chemical signals and the genetic blueprint, cellular function and dynamics are modulated by the physical properties of their environment such as stiffness and topography. In order to probe and respond to these environmental attributes, cells exert forces on their surroundings and generate appropriate biochemical and genetic responses. These forces arise from the spatiotemporal organization and dynamics of the cell cytoskeleton, a network of entangled biopolymer filaments that is driven out of thermal equilibrium by enzymes that actively convert chemical energy to mechanical energy. Understanding how cells generate forces and sense the mechanical environment is an important challenge with implications for physics and biology. I will discuss our work on the principles of cellular force generation, the statistical properties of these forces, and their role in stiffness and topography sensing, with a focus on immune and cancer cells. During activation, immune cells interact with structures possessing a diverse range of physical properties and are mechanosensitive. I will discuss the roles of the actin and microtubule cytoskeleton in force exertion and receptor movements during T cell activation in response to physical cues. I will also present some recent results on chromatin and transcription factor dynamics with a view to understanding how the mechanical properties of the environment affect gene expression in cancer cells. Our work provides insight into the design principles underlying how biologically active matter controls signaling and gene expression and underscores the importance of physical forces in cellular function.

Arpita Upadhyaya studies how cellular mechanics and the physical forces that enable a cell to sense and respond to its physical environment, in particular cells of the immune system and cancer cells.

Originally published at biophysics.nd.edu.