scholarly journals Tau aggregation and its relation to selected forms of neuronal cell death

2021 ◽  
Author(s):  
Aviva M. Tolkovsky ◽  
Maria Grazia Spillantini
Keyword(s):  
Cell Death ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Death Process ◽  
Cellular Functions ◽  
Microglial Phagocytosis ◽  
Related Cell ◽  
Cell Death Process ◽  
Tau Aggregation ◽  
Tau Aggregate

Abstract How neurons die in neurodegenerative diseases is still unknown. The distinction between apoptosis as a genetically controlled mechanism, and necrosis, which was viewed as an unregulated process, has blurred with the ever-increasing number of necrotic-like death subroutines underpinned by genetically defined pathways. It is therefore pertinent to ask whether any of them apply to neuronal cell death in tauopathies. Although Alzheimer’s disease (AD) is the most prevalent tauopathy, tauopathies comprise an array of over 30 diseases in which the cytoplasmic protein tau aggregates in neurons, and also, in some diseases, in glia. Animal models have sought to distil the contribution of tau aggregation to the cell death process but despite intensive research, no one mechanism of cell death has been unequivocally defined. The process of tau aggregation, and the fibrillar structures that form, touch on so many cellular functions that there is unlikely to be a simple linear pathway of death; as one is blocked another is likely to take the lead. It is timely to ask how far we have advanced into defining whether any of the molecular players in the new death subroutines participate in the death process. Here we briefly review the currently known cell death routines and explore what is known about their participation in tau aggregation-related cell death. We highlight the involvement of cell autonomous and the more recent non-cell autonomous pathways that may enhance tau-aggregate toxicity, and discuss recent findings that implicate microglial phagocytosis of live neurons with tau aggregates as a mechanism of death.

NEURODEGENERATION PROCESSES GO FAR BEYOND NECROSIS AND APOPTOSIS!

2021 ◽  
Vol 1 (1) ◽  
pp. 1-19
Author(s):  
Rogério De Freitas Lacerda ◽  
Abigail Gonçalves da Silva ◽  
Isabela Cristina Sena Romano
Keyword(s):  
Cell Death ◽  
Neural Plasticity ◽  
Neuronal Cell Death ◽  
Morphological Characteristics ◽  
Neuronal Cell ◽  
Death Process ◽  
Molecular Systems ◽  
Cell Death Process ◽  
Dependent Cell ◽  
Apoptosis And Necrosis

Neural plasticity is a consequence of a delicate balance between the processes of neurodegeneration and neurogenesis. When neurodegeneration overcomes neurogenesis, neurodegenerative diseases occur, which affect cognitive functions such as memory, language, and executive functions. Neurodegeneration, the process of neuronal cell death, presents several aspects that were categorized according to their macroscopic and/or morphological characteristics. The concept of apoptosis, autophagy, and necrosis is still widely used today. On the other hand, more in-depth forms emerge in the clinical and academia, describing the cascade of cell death events through biochemical approaches, and the essential (causal) and accessory (correlative) aspects of the cell death process. New concepts were introduced, addressed in the modules of signal translation involving issues such as the initiation, execution, and propagation of cell death, as well as the pathophysiological relevance of each of the main types. Currently, twelve types of cell death are already defined, not only apoptosis, necrosis, and autophagy. In this review, we will address the main mechanisms of cell death, with special emphasis on the participation of caspases and other proteins in these mechanisms. We will discuss some types of cell death such as extrinsic and intrinsic apoptosis, necrosis, necroptosis, and autophagy-dependent cell death. We hope to elucidate key points in molecular systems, including the receptors involved in cell death and their role in neurodegeneration, and showing that neurodegeneration has characteristics beyond morphological (apoptosis and necrosis).

scholarly journals Pivotal Role of Receptor-Interacting Protein Kinase 1 and Mixed Lineage Kinase Domain-Like in Neuronal Cell Death Induced by the Human Neuroinvasive Coronavirus OC43

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Mathieu Meessen-Pinard ◽  
Alain Le Coupanec ◽  
Marc Desforges ◽  
Pierre J. Talbot
Keyword(s):  
Cell Death ◽  
Significant Role ◽  
Neurological Diseases ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Pivotal Role ◽  
Death Process ◽  
Potential Implication ◽  
Human Coronaviruses

ABSTRACT Human coronaviruses (HCoV) are respiratory pathogens with neuroinvasive, neurotropic, and neurovirulent properties, highlighting the importance of studying the potential implication of these viruses in neurological diseases. The OC43 strain (HCoV-OC43) was reported to induce neuronal cell death, which may participate in neuropathogenesis. Here, we show that HCoV-OC43 harboring two point mutations in the spike glycoprotein (rOC/Us183–241) was more neurovirulent than the wild-type HCoV-OC43 (rOC/ATCC) in mice and induced more cell death in murine and human neuronal cells. To evaluate the role of regulated cell death (RCD) in HCoV-OC43-mediated neural pathogenesis, we determined if knockdown of Bax, a key regulator of apoptosis, or RIP1, a key regulator of necroptosis, altered the percentage of neuronal cell death following HCoV-OC43 infection. We found that Bax-dependent apoptosis did not play a significant role in RCD following infection, as inhibition of Bax expression mediated by RNA interference did not confer cellular protection against the cell death process. On the other hand, we demonstrated that RIP1 and MLKL were involved in neuronal cell death, as RIP1 knockdown and chemical inhibition of MLKL significantly increased cell survival after infection. Taken together, these results indicate that RIP1 and MLKL contribute to necroptotic cell death after HCoV-OC43 infection to limit viral replication. However, this RCD could lead to neuronal loss in the mouse CNS and accentuate the neuroinflammation process, reflecting the severity of neuropathogenesis. IMPORTANCE Because they are naturally neuroinvasive and neurotropic, human coronaviruses are suspected to participate in the development of neurological diseases. Given that the strain OC43 is neurovirulent in mice and induces neuronal cell death, we explored the neuronal response to infection by characterizing the activation of RCD. Our results revealed that classical apoptosis associated with the Bax protein does not play a significant role in HCoV-OC43-induced neuronal cell death and that RIP1 and MLKL, two cellular proteins usually associated with necroptosis (an RCD back-up system when apoptosis is not adequately induced), both play a pivotal role in the process. As necroptosis disrupts cellular membranes and allows the release of damage-associated molecular patterns (DAMP) and possibly induces the production of proinflammatory cytokines, it may represent a proinflammatory cell death mechanism that contributes to excessive neuroinflammation and neurodegeneration and eventually to neurological disorders after a coronavirus infection.

scholarly journals A proteomic analysis of the effect of mapk pathway activation on l-glutamate-induced neuronal cell death

2007 ◽  
Vol 12 (1) ◽  
Author(s):  
Sunghyun Kang ◽  
Eun Kim ◽  
Young Bahn ◽  
Jin Chung ◽  
Do Lee ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Proteomic Analysis ◽  
Mapk Pathway ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Mapk Signaling ◽  
Cytoskeletal Proteins ◽  
Death Process ◽  
Differential Expression Pattern

AbstractOxidative stress has been implicated in the pathogenesis of neuronal degenerative diseases. It is also widely known that oxidative stress induces mitogen-activated protein kinase (MAPK) signaling cascades. In this study, we used proteomic analysis to investigate the role of the MAPK pathway in oxidative stress-induced neuronal cell death. The results demonstrated that several proteins, including eukaryotic translation elongation factor 2 (eEF2) and enolase I, showed a differential expression pattern during the neuronal cell death process, and this was MAPK pathway dependent. Several chaperone and cytoskeletal proteins including heat shock protein 70, calreticulin, vimentin, prolyl 4-hydroxylase β polypeptide, and transgelin 2 were up-or down-regulated, despite their expressions not depending on the MAPK pathway. These findings strongly suggest that the expressions of proteins which play protective roles are independent of the MAPK pathway. On the other hand, eEF2 and enolase I may be the downstream targets of the MAPK pathway.

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