Oxidized phospholipids (OxPLs) represent a class of molecules generated during evolution that shift from fundamental membrane building-blocks to key signaling mediators, linking lipid metabolism, cellular redox homeostasis and multi-faceted cell-fate control. Generated by both enzymatic and non-enzymatic peroxidation events, OxPLs engage in extensive signaling crosstalk with lyso-phospholipids and oxylipins. The FerroLipid framework describes iron-lipid peroxidation crosstalk to contextualize iron-dependent lipid signaling. OxPLs govern diverse regulated cell-death programs: they act as lipid death signals in apoptosis and ferroptosis, tune ferroptotic outputs through intrinsic antioxidant systems, and exert context-specific modulatory effects on pyroptosis and other cell-death modalities. Beyond cell-death execution, OxPLs signal through pattern-recognition, scavenger and nuclear receptors to orchestrate inflammation, membrane remodeling, phagocytic clearance, autophagy, mitophagy and protein homeostasis. Threshold-dependent accumulation of OxPLs drives pathological processes across neurodegenerative, metabolic, cardiovascular, neoplastic and infectious diseases; their disease-specific molecular signatures confer potential as both diagnostic biomarkers and therapeutic targets. Redox phospholipidomics coupled with mass-spectrometry imaging enables accurate, species-resolved profiling of distinct OxPL species. Multiple pharmacological approaches and gene-editing interventions have demonstrated tangible translational prospects for OxPL-oriented therapy. This review synthesizes existing knowledge of OxPL biology from evolutionary origins and signaling mechanisms to disease relevance, analytical tools and therapeutic opportunities. It highlights major unresolved research bottlenecks and provides a solid conceptual foundation for advancing lipid-targeted treatments for complex human disorders.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.