Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field.

https://biblio.ugent.be/publication/8555786/file/8555788.pdf

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

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.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

Effects of Intermittent Fasting on Health and Aging Evidence is accumulating that eating in a 6-hour period and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-base...

https://www.nejm.org/doi/pdf/10.1056/NEJMra1905136

Effects of Intermittent Fasting on Health, Aging, and Disease

Ageing is a major risk factor for the development of many diseases, prominently including neurodegenerative disorders such as Alzheimer disease and Parkinson disease. A hallmark of many age-related diseases is the dysfunction in protein homeostasis (proteostasis), leading to the accumulation of protein aggregates. In healthy cells, a complex proteostasis network, comprising molecular chaperones and proteolytic machineries and their regulators, operates to ensure the maintenance of proteostasis. These factors coordinate protein synthesis with polypeptide folding, the conservation of protein conformation and protein degradation. However, sustaining proteome balance is a challenging task in the face of various external and endogenous stresses that accumulate during ageing. These stresses lead to the decline of proteostasis network capacity and proteome integrity. The resulting accumulation of misfolded and aggregated proteins affects, in particular, postmitotic cell types such as neurons, manifesting in disease. Recent analyses of proteome-wide changes that occur during ageing inform strategies to improve proteostasis. The possibilities of pharmacological augmentation of the capacity of proteostasis networks hold great promise for delaying the onset of age-related pathologies associated with proteome deterioration and for extending healthspan. Misfolded proteins have a high propensity to form potentially toxic aggregates. Cells employ a complex network of processes, involving chaperones and proteolytic machineries that ensure proper protein folding and remodel or degrade misfolded species and aggregates. This proteostasis network declines with age, which can be linked to human degenerative diseases.

/pdf/the-proteostasis-network-and-its-decline-in-ageing-37kiacdc8l.pdf

The proteostasis network and its decline in ageing.

Neuronal cell death occurs extensively during development and pathology, where it is especially important because of the limited capacity of adult neurons to proliferate or be replaced. The concept of cell death used to be simple as there were just two or three types, so we just had to work out which type was involved in our particular pathology and then block it. However, we now know that there are at least a dozen ways for neurons to die, that blocking a particular mechanism of cell death may not prevent the cell from dying, and that non-neuronal cells also contribute to neuronal death. We review here the mechanisms of neuronal death by intrinsic and extrinsic apoptosis, oncosis, necroptosis, parthanatos, ferroptosis, sarmoptosis, autophagic cell death, autosis, autolysis, paraptosis, pyroptosis, phagoptosis, and mitochondrial permeability transition. We next explore the mechanisms of neuronal death during development, and those induced by axotomy, aberrant cell-cycle reentry, glutamate (excitoxicity and oxytosis), loss of connected neurons, aggregated proteins and the unfolded protein response, oxidants, inflammation, and microglia. We then reassess which forms of cell death occur in stroke and Alzheimer's disease, two of the most important pathologies involving neuronal cell death. We also discuss why it has been so difficult to pinpoint the type of neuronal death involved, if and why the mechanism of neuronal death matters, the molecular overlap and interplay between death subroutines, and the therapeutic implications of these multiple overlapping forms of neuronal death.

Neuronal Cell Death.

Autophagy and Neurodegeneration: Pathogenic Mechanisms and Therapeutic Opportunities

Autophagy is a highly conserved cytoplasmic degradation pathway that has an impact on many physiological and disease states, including immunity, tumorigenesis and neurodegeneration. Recent studies suggest that autophagy may also have important functions in embryogenesis and development. Many autophagy gene-knockout mice have embryonic lethality at different stages of development. Furthermore, interactions of autophagy with crucial developmental pathways such as Wnt, Shh (Sonic Hedgehog), TGFβ (transforming growth factor β) and FGF (fibroblast growth factor) have been reported. This suggests that autophagy may regulate cell fate decisions, such as differentiation and proliferation. In the present article, we discuss how mammalian autophagy may affect phenotypes associated with development.

Autophagy and mammalian development

https://doi.org/10.1016/j.neuron.2023.04.006

Microglial-to-neuronal CCR5 signaling regulates autophagy in neurodegeneration

Comparison of Plaque Reduction and Focus Reduction Neutralization Tests for the Measurement of Neutralizing Antibody Titers Against Japanese Encephalitis Virus.

Comparison of Plaque Reduction and Focus Reduction Neutralization Tests for the Measurement of Neutralizing Antibody Titers Against Japanese Encephalitis Virus

Hyeran Won

Papers

Autophagy and Neurodegeneration: Pathogenic Mechanisms and Therapeutic Opportunities

Autophagy and mammalian development

Microglial-to-neuronal CCR5 signaling regulates autophagy in neurodegeneration

Comparison of Plaque Reduction and Focus Reduction Neutralization Tests for the Measurement of Neutralizing Antibody Titers Against Japanese Encephalitis Virus.

Comparison of Plaque Reduction and Focus Reduction Neutralization Tests for the Measurement of Neutralizing Antibody Titers Against Japanese Encephalitis Virus