scholarly journals BID and the α-bisabolol-triggered cell death program: converging on mitochondria and lysosomes

2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Antonella Rigo ◽  
Isacco Ferrarini ◽  
Erika Lorenzetto ◽  
Elena Darra ◽  
Irene Liparulo ◽  
...  
Keyword(s):  
Cell Death ◽  
Blood Cells ◽  
Pore Formation ◽  
Neoplastic Cell ◽  
Autophagic Flux ◽  
Cytotoxic Effects ◽  
Sesquiterpene Alcohol ◽  
Regulated Cell Death ◽  
Cell Death Program ◽  
Microscopy Techniques

Abstractα-Bisabolol (BSB) is a plant-derived sesquiterpene alcohol able to trigger regulated cell death in transformed cells, while deprived of the general toxicity in several mouse models. Here, we investigated the involvement of lysosomal and mitochondrial compartments in the cytotoxic effects of BSB, with a specific focus on the BH3-only activator protein BID. We found that BSB particularly accumulated in cancer cell lines, displaying a higher amount of lipid rafts as compared to normal blood cells. By means of western blotting and microscopy techniques, we documented rapid BSB-induced BID translocation to lysosomes and mitochondria, both of them becoming dysfunctional. Lysosomal membranes were permeabilized, thus blocking the cytoprotective autophagic flux and provoking cathepsin B leakage into the cytosol. Multiple flow cytometry-based experiments demonstrated the loss of mitochondrial membrane potential due to pore formation across the lipid bilayer. These parallel events converged on neoplastic cell death, an outcome significantly prevented by BID knockdown. Therefore, BSB promoted BID redistribution to the cell death executioner organelles, which in turn activated anti-autophagic and proapoptotic mechanisms. This is an example of how xenohormesis can be exploited to modulate basic cellular programs in cancer.

scholarly journals Effect of Calomelanone, a Dihydrochalcone Analogue, on Human Cancer Apoptosis/Regulated Cell Death in an In Vitro Model

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Wasitta Rachakhom ◽  
Ratana Banjerdpongchai
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Hepg2 Cells ◽  
Cytotoxic Effect ◽  
Human Cancer ◽  
Autophagic Flux ◽  
Dependent Manner ◽  
Anticancer Activities ◽  
Human Cancer Cells ◽  
Regulated Cell Death

Calomelanone, 2 ′ ,6 ′ -dihydroxy-4,4 ′ -dimethoxydihydrochalcone, possesses anticancer activities. This study was conducted to investigate the cytotoxic effect of calomelanone, a dihydrochalcone analogue, on human cancer cells and its associated mechanisms. The cytotoxic effect of calomelanone was measured by MTT assay. Annexin V-FITC/propidium iodide and DiOC6 staining that employed flow cytometry were used to determine the mode of cell death and reduction of mitochondrial transmembrane potential (MTP), respectively. Caspase activities were measured using specific substrates and colorimetric analysis. The expression levels of Bcl-2 family proteins were determined by immunoblotting. Reactive oxygen species were also measured using 2 ′ ,7 ′ -dihydrodichlorofluorescein diacetate and dihydroethidium (fluorescence dyes). Calomelanone was found to be toxic towards various human cancer cells, including acute promyelocytic HL-60 and monocytic leukemic U937 cells, in a dose-dependent manner at 24 h and human hepatocellular HepG2 cells at 48 h. However, the proliferation of HepG2 cells increased at 24 h. Calomelanone was found to induce apoptosis in HL-60 and U937 at 24 h and HepG2 apoptosis at 48 h via the intrinsic pathway by inducing MTP disruption. This compound also induced caspase-3, caspase-8, and caspase-9 activities. Calomelanone upregulated proapoptotic Bax and Bak and downregulated antiapoptotic Bcl-xL proteins in HepG2 cells. Moreover, signaling was also associated with oxidative stress in HepG2 cells. Calomelanone induced autophagy at 24 h of treatment, which was evidenced by staining with monodansylcadaverine (MDC) to represent autophagic flux. This was associated with a decrease of Akt (survival pathway) and an upregulation of Atg5 (the marker of autophagy). Thus, calomelanone induced apoptosis/regulated cell death in HL-60, U937, and HepG2 cells. However, it also induced autophagy in HepG2 depending on duration, dose, and type of cells. Thus, calomelanone could be used as a potential anticancer agent for cancer treatment. Nevertheless, acute and chronic toxicity should be further investigated in animals before conducting investigations in human patients.

scholarly journals Bacterial gasdermins reveal an ancient mechanism of cell death

2021 ◽  
Author(s):  
Alex G Johnson ◽  
Tana Wein ◽  
Megan L Mayer ◽  
Brianna Duncan-Lowey ◽  
Erez Yirmiya ◽  
...  
Keyword(s):  
Cell Death ◽  
Pore Formation ◽  
Membrane Integrity ◽  
Lipid Modification ◽  
Site Specific ◽  
Prokaryotic Cell ◽  
Inactive State ◽  
Membrane Pores ◽  
Regulated Cell Death ◽  
Peptide Release

Gasdermin proteins form large membrane pores in human cells that release immune cytokines and induce lytic cell death. Gasdermin pore formation is triggered by caspase-mediated cleavage during inflammasome signaling and is critical for defense against pathogens and cancer. Here we discover gasdermin homologs encoded in bacteria that execute prokaryotic cell death. Structures of bacterial gasdermins reveal a conserved pore-forming domain that is stabilized in the inactive state with a buried lipid modification. We demonstrate that bacterial gasdermins are activated by dedicated caspase-like proteases that catalyze site-specific cleavage and removal of an inhibitory C-terminal peptide. Release of autoinhibition induces the assembly of >200 Å pores that form a mesh-like structure and disrupt membrane integrity. These results demonstrate that caspase-mediated activation of gasdermins is an ancient form of regulated cell death shared between bacteria and animals.

scholarly journals Heat stress induces ferroptosis in a photosynthetic prokaryote

2019 ◽  
Author(s):  
Anabella Aguilera ◽  
Federico Berdun ◽  
Carlos Bartoli ◽  
Charlotte Steelheart ◽  
Matías Alegre ◽  
...  
Keyword(s):  
Cell Death ◽  
Heat Stress ◽  
Similar Process ◽  
Cell Death Pathway ◽  
Regulated Cell Death ◽  
Cell Death Program ◽  
Dependent Form ◽  
A Cell ◽  
Eukaryotic Organisms ◽  
Pcc 6803

AbstractFerroptosis is an oxidative iron-dependent form of cell death recently described in eukaryotic organisms like animals, plants and parasites. Here we report that a similar process takes place in the cyanobacterium Synechocystis sp. PCC 6803 in response to heat stress. After a heat shock, Synechocystis cells undergo a cell death pathway that can be suppressed by canonical ferroptosis inhibitors or by external addition of calcium, glutathione or ascorbic acid. Moreover, as described for eukaryotic cells ferroptosis, this pathway is characterized by an early depletion of antioxidants, and by lipid peroxidation. As in general prokaryotes membranes contain poorly oxidizable saturated or monounsaturated lipid molecules, it was thought that they were not susceptible to ferroptosis. Interestingly, cyanobacteria contain thylakoid membranes that are enriched in polyunsaturated-fatty-acid-containing phospholipids, which might explain their sensitivity to ferroptosis. 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.SummaryAguilera et al, show that ferroptosis, an oxidative and iron-dependent form of regulated cell death, plays an important role in the cyanobacterium Synechocystis sp. PCC 6803 in response to heat stress.

scholarly journals Blunted Fas signaling favors RIPK1-driven neutrophil necroptosis in critically ill COVID-19 patients

2021 ◽  
Author(s):  
Tiziano A Schweizer ◽  
Srikanth Mairpady Shambat ◽  
Clement Vulin ◽  
Sylvia Hoeller ◽  
Claudio Acevedo ◽  
...  
Keyword(s):  
Cell Death ◽  
Disease Severity ◽  
Critically Ill ◽  
Cytokine Profile ◽  
Caspase 8 ◽  
Potential Therapeutic Target ◽  
Regulated Cell Death ◽  
Cell Death Program ◽  
Fas Signaling ◽  
The Impact

Critically ill COVID-19 patients are characterized by a severely dysregulated cytokine profile and elevated neutrophil counts, which are thought to contribute to disease severity. However, to date it remains unclear how neutrophils contribute to pathophysiology during COVID-19. Here, we assessed the impact of the dysregulated cytokine profile on the tightly regulated cell death program of neutrophils. We show that in a subpopulation of neutrophils, canonical apoptosis was skewed towards rapidly occurring necroptosis. This phenotype was characterized by abrogated caspase-8 activity and increased RIPK1 levels, favoring execution of necroptosis via the RIPK1-RIPK3-MLKL axis, as further confirmed in COVID-19 biopsies. Moreover, reduction of sFas-L levels in COVID-19 patients and hence decreased signaling to Fas directly increased RIPK1 levels and correlated with disease severity. Our results suggest an important role for Fas signaling in the regulation of cell death program ambiguity via the ripoptosome in neutrophils during COVID-19 and a potential therapeutic target to curb inflammation and thus influence disease severity and outcome.

scholarly journals Pore formation in regulated cell death

2020 ◽  
Vol 39 (23) ◽  
Author(s):  
Hector Flores‐Romero ◽  
Uris Ros ◽  
Ana J Garcia‐Saez
Keyword(s):  
Cell Death ◽  
Pore Formation ◽  
Regulated Cell Death

scholarly journals The Receptor Interacting Protein Kinases in the Liver

2018 ◽  
Vol 38 (01) ◽  
pp. 073-086 ◽  
Author(s):  
Lily Dara
Keyword(s):  
Cell Death ◽  
Liver Disease ◽  
Kinase Activity ◽  
Cultured Cells ◽  
Interacting Protein ◽  
Regulated Cell Death ◽  
Cell Death Program ◽  
Cell Death Signaling ◽  
Experimental Liver ◽  
Mediate Inflammation

AbstractThe receptor interacting serine/threonine kinase1 and 3 (RIPK1, RIPK3) are regulators of cell death and survival. RIPK1 kinase activity is required for necroptosis and apoptosis, while its scaffolding function is necessary for survival. Although both proteins can mediate apoptosis, RIPK1 and RIPK3 are most well-known for their role in the execution of necroptosis via the mixed lineage domain like pseudokinase. Necroptosis is a caspase-independent regulated cell death program which was first described in cultured cells with unknown physiologic relevance in the liver. Many recent reports have suggested that RIPK1 and/or RIPK3 participate in liver disease pathogenesis and cell death. Notably, both proteins have been shown to mediate inflammation independent of cell death. Whether necroptosis occurs in hepatocytes, and how it is executed in the presence of an intact caspase machinery is controversial. In spite of this controversy, it is evident that RIPK1 and RIPK3 participate in many experimental liver disease models. Therefore, in addition to cell death signaling, their necroptosis-independent role warrants further examination.

scholarly journals Collateral damage: necroptosis in the development of lung injury

2020 ◽  
Vol 318 (2) ◽  
pp. L215-L225 ◽  
Author(s):  
Hilary Faust ◽  
Nilam S. Mangalmurti
Keyword(s):  
Cell Death ◽  
Lung Injury ◽  
Bacterial Pneumonia ◽  
Collateral Damage ◽  
Laboratory Findings ◽  
Diverse Range ◽  
Regulated Cell Death ◽  
Extracellular Release ◽  
Cell Death Program

Cell death is increasingly recognized as a driving factor in the development of acute lung injury. Necroptosis, an immunogenic regulated cell death program important in innate immunity, has been implicated in the development of lung injury in a diverse range of conditions. Characterized by lytic cell death and consequent extracellular release of endogenous inflammatory mediators, necroptosis can be both beneficial and deleterious to the host, depending on the context. Here, we review recent investigations linking necroptosis and the development of experimental lung injury. We assess the consequences of necroptosis during bacterial pneumonia, viral infection, sepsis, and sterile injury, highlighting increasing evidence from in vitro studies, animal models, and clinical studies that implicates necroptosis in the pathogenesis of ARDS. Lastly, we highlight current challenges in translating laboratory findings to the bedside.

C-ferroptosis is an iron-dependent form of regulated cell death in cyanobacteria

2021 ◽  
Vol 221 (2) ◽  
Author(s):  
Anabella Aguilera ◽  
Federico Berdun ◽  
Carlos Bartoli ◽  
Charlotte Steelheart ◽  
Matías Alegre ◽  
...  
Keyword(s):  
Cell Death ◽  
Similar Process ◽  
Cell Death Pathway ◽  
Regulated Cell Death ◽  
Cell Death Program ◽  
Dependent Form ◽  
A Cell ◽  
Eukaryotic Organisms ◽  
Synechocystis Sp ◽  
Pcc 6803

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.

scholarly journals Gasdermin D pores are dynamically regulated by local phosphoinositide circuitry

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Ana Beatriz Santa Cruz Garcia ◽  
Kevin P. Schnur ◽  
Asrar B. Malik ◽  
Gary C. H. Mo
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Pore Formation ◽  
Inflammatory Cytokine ◽  
Living Cells ◽  
Live Cell ◽  
Pore Geometry ◽  
Cytokine Release ◽  
Cell Death Program ◽  
And Control

AbstractGasdermin D forms large, ~21 nm diameter pores in the plasma membrane to drive the cell death program pyroptosis. These pores are thought to be permanently open, and the resultant osmotic imbalance is thought to be highly damaging. Yet some cells mitigate and survive pore formation, suggesting an undiscovered layer of regulation over the function of these pores. However, no methods exist to directly reveal these mechanistic details. Here, we combine optogenetic tools, live cell fluorescence biosensing, and electrophysiology to demonstrate that gasdermin pores display phosphoinositide-dependent dynamics. We quantify repeated and fast opening-closing of these pores on the tens of seconds timescale, visualize the dynamic pore geometry, and identify the signaling that controls dynamic pore activity. The identification of this circuit allows pharmacological tuning of pyroptosis and control of inflammatory cytokine release by living cells.

scholarly journals Sequential Activation of Poly(ADP-Ribose) Polymerase 1, Calpains, and Bax Is Essential in Apoptosis-Inducing Factor-Mediated Programmed Necrosis

2007 ◽  
Vol 27 (13) ◽  
pp. 4844-4862 ◽  
Author(s):  
Rana S. Moubarak ◽  
Victor J. Yuste ◽  
Cédric Artus ◽  
Aïda Bouharrour ◽  
Peter A. Greer ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Gene Knockout ◽  
Chromatin Condensation ◽  
Parp Activation ◽  
Regulated Cell Death ◽  
Molecular Ordering ◽  
Independent Form ◽  
Cell Death Program ◽  
Parp 1

ABSTRACT Alkylating DNA damage induces a necrotic type of programmed cell death through the poly(ADP-ribose) polymerases (PARP) and apoptosis-inducing factor (AIF). Following PARP activation, AIF is released from mitochondria and translocates to the nucleus, where it causes chromatin condensation and DNA fragmentation. By employing a large panel of gene knockout cells, we identified and describe here two essential molecular links between PARP and AIF: calpains and Bax. Alkylating DNA damage initiated a p53-independent form of death involving PARP-1 but not PARP-2. Once activated, PARP-1 mediated mitochondrial AIF release and necrosis through a mechanism requiring calpains but not cathepsins or caspases. Importantly, single ablation of the proapoptotic Bcl-2 family member Bax, but not Bak, prevented both AIF release and alkylating DNA damage-induced death. Thus, Bax is indispensable for this type of necrosis. Our data also revealed that Bcl-2 regulates N-methyl-N′-nitro-N′-nitrosoguanidine-induced necrosis. Finally, we established the molecular ordering of PARP-1, calpains, Bax, and AIF activation, and we showed that AIF downregulation confers resistance to alkylating DNA damage-induced necrosis. Our data shed new light on the mechanisms regulating AIF-dependent necrosis and support the notion that, like apoptosis, necrosis could be a highly regulated cell death program.

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