CD9-dependent extracellular vesicles mediate the propagation of ferroptosis
Ferroptosis is a form of regulated cell death that is mediated by accumulation of lipid peroxidation. Emerging evidences report dispersion of ferroptosis between neighboring cells. However, the molecular mechanism underlying the propagation of ferroptosis remains unclear. Here we provide evidences that ferroptotic cells elicit cellular projections that produce massive extracellular vesicles (EVs). Proteomic analysis reveals that these EVs are CD9 positive and contain major components of mitogen-activated protein kinase (MAPK) signaling. MAP2K1/2 that is transferred by EVs increases the sensitivity to ferroptosis of target cells. We further show that a MAP2K-interacting transcription factor, peroxisome-proliferator activator receptor gamma (PPARG), activates various components of ferroptosis defense systems. Moreover, perturbation of EV-based transport protects adjacent tissue from ferroptosis in vivo. Our study reveals an EV-dependent transport between ferroptotic cells and surrounding neighbors and establishes that MAPK-responsive PPARG is essential for ferroptosis defense in recipient cells. Overall design: U-2 OS cells expressing PPARG-EGFP were used CUT&Tag-sequencing to analyze PPARG regulating genes.  Antibody against EGFP was used and three replicates were analysed.