SPATIO-TEMPORAL QUANTIFICATION OF CELL DEATH AND THE INTERPLAY BETWEEN AUTONOMOUS AND NON-AUTONOMOUS DEATH IN FERROPTOSIS

Cell death is a tightly regulated cell function that is critical for proper embryonic development and tissue homeostasis. While most forms of cell death are studied under the premise that an individual cell’s death has no effect on its surrounding neighbor cells, emerging evidence indicates that death can spread between the individual cells in a population. For example, Ferroptosis is an iron-dependent form of cell death that can rapidly eliminate entire groups of cells across a population via spreading. Current methods quantify the fraction of dead cells in static snapshots or over time without considering the spatial component. We developed methods to measure the spatiotemporal dynamics of collective cell death at the single cell level. Specifically, we decouple two cellular mechanisms that together contribute to the spreading of cell death within a population: (1) cell death nucleation, the cell-autonomous component that is caused by the external stress experienced by all cells; and (2) cell death propagation, the transmission of a death signal from one cell to its neighbors. We first applied this methodology to validate that ferroptosis was dominated by non-autonomous propagation while apoptosis by autonomous nucleation. This was followed by precise characterization of the spatiotemporal death patterns of different forms of ferroptosis induction. Our methodology enables to bridge single cell and collective cell decision-making by measuring how information propagates between scales to enable biological function.