A10: Garcia-Saez

Permeabilization of cellular membranes by pore formation is a common feature in the progression of regulated forms of cell death. In the case of pyroptosis, Gasdermin D forms well-defined beta-barrel pores, while in necroptosis, MLKL (mixed lineage kinase domain-like pseudokinase) disrupts the barrier function of the plasma membrane via an unknown mechanism. Pore formation is counterbalanced in these cell death modalities by membrane repair mechanisms aimed at maintaining membrane integrity up to a certain threshold. In the case of necroptosis and pyroptosis, the ESCRT machinery has been shown to play a role in the inhibition cell death likely by removing the MLKL or Gasdermin D pores through vesicles that are pinched off the plasma membrane. However, how the balance between the extent of plasma membrane permeabilization and repair define the point of final cellular collapse and cell death remains unknown. The goal of this project is to understand the interplay between death pore formation and the counterbalancing mechanisms that are crucial for the decision between cell death and survival in pyroptosis and necroptosis. We will compare the extent of plasma membrane permeabilization that cells can withstand in these two forms of cell death, as well as the relative relevance of the compensatory role of different membrane repair mechanisms in delaying cell death, both in human liver carcinoma cells and in human colon cancer cells. Finally, we aim to define how the modulation of these mechanisms can be exploited to tune the decision-making process for each form of cell death.