RESUMEN
Ferroptosis is an oxidative and iron-dependent form of regulated cell death (RCD) recently described in eukaryotic organisms like animals, plants, and parasites. Here, we report that a similar process takes place in the photosynthetic prokaryote Synechocystis sp. PCC 6803 in response to heat stress. After a heat shock, Synechocystis sp. PCC 6803 cells undergo a cell death pathway that can be suppressed by the canonical ferroptosis inhibitors, CPX, vitamin E, Fer-1, liproxstatin-1, glutathione (GSH), or ascorbic acid (AsA). Moreover, as described for eukaryotic ferroptosis, this pathway is characterized by an early depletion of the antioxidants GSH and AsA, and by lipid peroxidation. These results indicate that all of the hallmarks described for eukaryotic ferroptosis are conserved in photosynthetic prokaryotes and suggest that ferroptosis might be an ancient cell death program.
Asunto(s)
Cianobacterias/citología , Cianobacterias/metabolismo , Ferroptosis , Hierro/metabolismo , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Calcio/metabolismo , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Citosol/metabolismo , Glutatión/metabolismo , Respuesta al Choque Térmico , Lipidómica , Lípidos/química , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Synechocystis/metabolismo , Tilacoides/metabolismoRESUMEN
Ascorbic acid (AsA) and gluthathione (GSH) are two key components of the antioxidant machinery of eukaryotic and prokaryotic cells. The cyanobacterium Synechocystis sp. PCC 6803 presents both compounds in different concentrations (AsA, 20-100 µM and GSH, 2-5 mM). Therefore, it is important to have precise and sensitive methods to determine the redox status in the cell and to detect variations in this antioxidants. In this protocol, we describe an improved method to estimate the content of both antioxidants (in their reduced and oxidized forms) from the same sample obtained from liquid cultures of Synechocystis sp. PCC 6803.