scholarly journals Association of Active Caspase 8 with the Mitochondrial Membrane during Apoptosis: Potential Roles in Cleaving BAP31 and Caspase 3 and Mediating Mitochondrion-Endoplasmic Reticulum Cross Talk in Etoposide-Induced Cell Death

2004 ◽  
Vol 24 (15) ◽  
pp. 6592-6607 ◽  
Author(s):  
Dhyan Chandra ◽  
Grace Choy ◽  
Xiaodi Deng ◽  
Bobby Bhatia ◽  
Peter Daniel ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Cross Talk ◽  
Membrane Fraction ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Dominant Negative ◽  
Caspase 8 ◽  
Death Domain ◽  
Active Caspase

ABSTRACT It was recently demonstrated that during apoptosis, active caspase 9 and caspase 3 rapidly accumulate in the mitochondrion-enriched membrane fraction (D. Chandra and D. G. Tang, J. Biol. Chem.278:17408-17420, 2003). We now show that active caspase 8 also becomes associated with the membranes in apoptosis caused by multiple stimuli. In MDA-MB231 breast cancer cells treated with etoposide (VP16), active caspase 8 is detected only in the membrane fraction, which contains both mitochondria and endoplasmic reticulum (ER), as revealed by fractionation studies. Immunofluorescence microscopy, however, shows that procaspase 8 and active caspase 8 predominantly colocalize with the mitochondria. Biochemical analysis demonstrates that both procaspase 8 and active caspase 8 are localized mainly on the outer mitochondrial membrane (OMM) as integral proteins. Functional analyses with dominant-negative mutants, small interfering RNAs, peptide inhibitors, and Fas-associated death domain (FADD)- and caspase 8-deficient Jurkat T cells establish that the mitochondrion-localized active caspase 8 results mainly from the FADD-dependent and tumor necrosis factor receptor-associated death domain-dependent mechanisms and that caspase 8 activation plays a causal role in VP16-induced caspase 3 activation and cell death. Finally, we present evidence that the OMM-localized active caspase 8 can activate cytosolic caspase 3 and ER-localized BAP31. Cleavage of BAP31 leads to the generation of ER- localized, proapoptotic BAP20, which may mediate mitochondrion-ER cross talk through a Ca2+-dependent mechanism.

scholarly journals p38-mediated Regulation of an Fas-associated Death Domain Protein-independent Pathway Leading to Caspase-8 Activation during TGFβ-induced Apoptosis in Human Burkitt Lymphoma B Cells BL41

2001 ◽  
Vol 12 (10) ◽  
pp. 3139-3151 ◽  
Author(s):  
Nicolas Schrantz ◽  
Marie-Françoise Bourgeade ◽  
Shahul Mouhamad ◽  
Gérald Leca ◽  
Surendra Sharma ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Transforming Growth Factor ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Caspase 8 ◽  
Death Domain ◽  
Apoptotic Pathway ◽  
Domain Protein

On binding to its receptor, transforming growth factor β (TGFβ) induces apoptosis in a variety of cells, including human B lymphocytes. We have previously reported that TGFβ-mediated apoptosis is caspase-dependent and associated with activation of caspase-3. We show here that caspase-8 inhibitors strongly decrease TGFβ-mediated apoptosis in BL41 Burkitt's lymphoma cells. These inhibitors act upstream of the mitochondria because they inhibited the loss of mitochondrial membrane potential observed in TGFβ-treated cells. TGFβ induced caspase-8 activation in these cells as shown by the cleavage of specific substrates, including Bid, and the appearance of cleaved fragments of caspase-8. Our data show that TGFβ induces an apoptotic pathway involving sequential caspase-8 activation, loss of mitochondrial membrane potential, and caspase-9 and -3 activation. Caspase-8 activation was Fas-associated death domain protein (FADD)-independent because cells expressing a dominant negative mutant of FADD were still sensitive to TGFβ-induced caspase-8 activation and apoptosis. This FADD-independent pathway of caspase-8 activation is regulated by p38. Indeed, TGFβ-induced activation of p38 and two different inhibitors specific for this mitogen-activated protein kinase pathway (SB203580 and PD169316) prevented TGFβ-mediated caspase-8 activation as well as the loss of mitochondrial membrane potential and apoptosis. Overall, our data show that p38 activation by TGFβ induced an apoptotic pathway via FADD-independent activation of caspase-8.

scholarly journals Co-involvement of the mitochondria and endoplasmic reticulum in cell death induced by the novel ertargeted protein HAP

2006 ◽  
Vol 11 (2) ◽  
Author(s):  
Hua Xu ◽  
Qing Zhou ◽  
Xin Liu ◽  
Yi-Peng Qi
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Membrane Potential ◽  
Hela Cells ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Protein A ◽  
The Novel ◽  
Induce Cell Apoptosis

AbstractHAP (a homologue of the ASY/Nogo-B protein), a novel human apoptosis-inducing protein, was found to be identical to RTN3. In an earlier study, we demonstrated that HAP localized exclusively to the endoplasmic reticulum (ER) and that its overexpression could induce cell apoptosis via a depletion of endoplasmic reticulum (ER) Ca2+ stores. In this study, we show that overexpression of HAP causes the activation of caspase-12 and caspase-3. We still detected the collapse of mitochondrial membrane potential (Δωm) and the release of cytochrome c in HAP-overexpressing HeLa cells. All the results indicate that both the mitochondria and the ER are involved in apoptosis caused by HAP overexpression, and suggest that HAP overexpression may initiate an ER overload response (EOR) and bring about the downstream apoptotic events.

scholarly journals Knock Out of Cell Death Pathway Components Results in Differential Caspase Expression in Response to HCV Infection

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 144
Author(s):  
Hannah L. Wallace ◽  
Lingyan Wang ◽  
Cassandra Davidson ◽  
Vipin Chelakkot ◽  
Michael Grant ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Cross Talk ◽  
Caspase 3 ◽  
Caspase Activation ◽  
Knock Out ◽  
Caspase 1 ◽  
Cell Death Pathway ◽  
Infected Cells ◽  
Active Caspase

Introduction: Pyroptosis (inflammatory programmed cell death) is induced after the activation of an inflammasome, ultimately resulting in pore formation and cell lysis. One factor in the pathology associated with chronic hepatitis C virus (HCV) infection is non-inflammatory caspase-3-mediated apoptosis. Our lab has found both apoptosis and pyroptosis occurring in HCV-infected Huh-7.5 cells. In the context of some viral infections, pyroptosis is beneficial to the virus; for others, pyroptosis is believed to represent an innate antiviral response. This study aimed to test the effects of knocking out components of the inflammasome pathway on caspase activation in HCV-infected cells. Methods: FAM-FLICA (Carboxyfluorescein - Fluorochrome Inhibitor of Caspases) probes or antibodies were used to visualize active caspase-1 and active caspase-3 in vitro. Huh-7.5 cells with components of the pyroptotic or apoptotic pathways knocked out (NLRP3, GSDM-D or caspase-3) were used to determine the effects of their absence on the virus and caspase activation using confocal microscopy and flow cytometry. Results: Increased levels of caspase-1 were consistently observed in HCV-infected cells compared to those in uninfected cells, and these levels increased with subsequent days post-infection. The inhibition of inflammasome activation using knock out cell lines induced the differential activation of caspase-1 and caspase-3, with the inhibition of pyroptosis, resulting in a trend towards greater expression of caspase-3, indicative of apoptosis. The inhibition of NLRP3 did not fully stop caspase-1 activation, but it was decreased. The flow cytometry results revealed a small sub-set of cells positive for both caspase-1 and caspase-3. Conclusions: These data confirm the occurrence of pyroptosis in HCV-infected cells and demonstrate the involvement of the NLRP3 inflammasome, although other inflammasome sensors might be involved. Since the inhibition of one cell death pathway resulted in the increased activation of the other, along with the presence of double-positive cells, there may be cross-talk between apoptotic and pyroptotic pathways; the role of this cross-talk during infection remains to be elucidated.

scholarly journals Caspase-8 Regulates Endoplasmic Reticulum Stress-Induced Necroptosis Independent of the Apoptosis Pathway in Auditory Cells

2019 ◽  
Vol 20 (23) ◽  
pp. 5896 ◽  
Author(s):  
Kishino ◽  
Hayashi ◽  
Maeda ◽  
Jike ◽  
Hidai ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Intrinsic Apoptosis ◽  
Caspase 9 ◽  
Apoptosis Pathway ◽  
Transmission Electron ◽  
Initiator Caspases

The aim of this study is to elucidate the detailed mechanism of endoplasmic reticulum (ER) stress-induced auditory cell death based on the function of the initiator caspases and molecular complex of necroptosis. Here, we demonstrated that ER stress initiates not only caspase-9-dependent intrinsic apoptosis along with caspase-3, but also receptor-interacting serine/threonine kinase (RIPK)1-dependent necroptosis in auditory cells. We observed the ultrastructural characteristics of both apoptosis and necroptosis in tunicamycin-treated cells under transmission electron microscopy (TEM). We demonstrated that ER stress-induced necroptosis was dependent on the induction of RIPK1, negatively regulated by caspase-8 in auditory cells. Our data suggested that ER stress-induced intrinsic apoptosis depends on the induction of caspase-9 along with caspase-3 in auditory cells. The results of this study reveal that necroptosis could exist for the alternative backup cell death route of apoptosis in auditory cells under ER stress. Interestingly, our data results in a surge in the recognition that therapies aimed at the inner ear protection effect by caspase inhibitors like zVAD-fmk might arrest apoptosis but can also have the unanticipated effect of promoting necroptosis. Thus, RIPK1-dependent necroptosis would be a new therapeutic target for the treatment of sensorineural hearing loss due to ER stress.

scholarly journals FADD (Fas-Associated Protein With Death Domain), Caspase-3, and Caspase-8 and Incidence of Ischemic Stroke

Stroke ◽  
2018 ◽  
Vol 49 (9) ◽  
pp. 2224-2226 ◽  
Author(s):  
Iram Faqir Muhammad ◽  
Yan Borné ◽  
Olle Melander ◽  
Marju Orho-Melander ◽  
Jan Nilsson ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Death Domain

scholarly journals Caspase-8 and Caspase-3 Are Expressed by Different Populations of Cortical Neurons Undergoing Delayed Cell Death after Focal Stroke in the Rat

1999 ◽  
Vol 19 (14) ◽  
pp. 5932-5941 ◽  
Author(s):  
James J. Velier ◽  
Julie A. Ellison ◽  
Kristine K. Kikly ◽  
Patricia A. Spera ◽  
Frank C. Barone ◽  
...  
Keyword(s):  
Cell Death ◽  
Cortical Neurons ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Delayed Cell Death ◽  
Different Populations

scholarly journals Inclusion Complex of Zerumbone with Hydroxypropyl-β-Cyclodextrin Induces Apoptosis in Liver Hepatocellular HepG2 Cells via Caspase 8/BID Cleavage Switch and Modulating Bcl2/Bax Ratio

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Nabilah Muhammad Nadzri ◽  
Ahmad Bustamam Abdul ◽  
Mohd Aspollah Sukari ◽  
Siddig Ibrahim Abdelwahab ◽  
Eltayeb E. M. Eid ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
Mitochondrial Membrane ◽  
Morphological Study ◽  
Caspase 3 ◽  
Anticancer Agent ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Solubility In Water ◽  
Anticancer Effects ◽  
First Time

Zerumbone (ZER) isolated fromZingiber zerumbetwas previously encapsulated with hydroxypropyl-β-cyclodextrin (HPβCD) to enhance ZER’s solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HPβCD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G2/M arrest. Further investigations showed the release of cytochrome c and loss of mitochondrial membrane potential, proving mitochondrial dysfunction upon the ZER-HPβCD treatment as well as modulating proapoptotic and anti-apototic Bcl-2 family members. A significant increase in caspase 3/7, caspase 9, and caspase 8 was detected with the depletion of BID cleaved by caspase 8. Collectively, these results prove that a highly soluble inclusion complex of ZER-HPβCD could be a promising anticancer agent for the treatment of hepatocellular carcinoma in humans.

scholarly journals Death Receptor-Induced Activation of Initiator Caspase 8 Is Antagonized by Serine/Threonine Kinase PAK4

2003 ◽  
Vol 23 (21) ◽  
pp. 7838-7848 ◽  
Author(s):  
Nerina Gnesutta ◽  
Audrey Minden
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Intracellular Signaling ◽  
Death Receptor ◽  
Caspase 8 ◽  
Death Domain ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Different Types ◽  
Promote Cell Survival

ABSTRACT Normal cell growth requires a precisely controlled balance between cell death and survival. This involves activation of different types of intracellular signaling cascades within the cell. While some types of signaling proteins regulate apoptosis, or programmed cell death, other proteins within the cell can promote survival. The serine/threonine kinase PAK4 can protect cells from apoptosis in response to several different types of stimuli. As is the case for other members of the p21-activated kinase (PAK) family, one way that PAK4 may promote cell survival is by phosphorylating and thereby inhibiting the proapoptotic protein Bad. This leads in turn to the inhibition of effector caspases such as caspase 3. Here we show that in response to cytokines which activate death domain-containing receptors, such as the tumor necrosis factor and Fas receptors, PAK4 can inhibit the death signal by a different mechanism. Under these conditions, PAK4 inhibits apoptosis early in the caspase cascade, antagonizing the activation of initiator caspase 8. This inhibition, which does not require PAK4's kinase activity, may involve inhibition of caspase 8 recruitment to the death domain receptors. This role in regulating initiator caspases is an entirely novel role for the PAK proteins and suggests a new mechanism by which these proteins promote cell survival.

scholarly journals The lysosomal Rag-Ragulator complex licenses RIPK1– and caspase-8–mediated pyroptosis by Yersinia

Science ◽  
2021 ◽  
Vol 372 (6549) ◽  
pp. eabg0269
Author(s):  
Zengzhang Zheng ◽  
Wanyan Deng ◽  
Yang Bai ◽  
Rui Miao ◽  
Shenglin Mei ◽  
...  
Keyword(s):  
Cell Death ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Host Cells ◽  
Caspase 8 ◽  
Death Domain ◽  
Interacting Protein ◽  
A Genome ◽  
Infection Inhibition ◽  
Guanosine Triphosphatase

Host cells initiate cell death programs to limit pathogen infection. Inhibition of transforming growth factor–β–activated kinase 1 (TAK1) by pathogenic Yersinia in macrophages triggers receptor-interacting serine-threonine protein kinase 1 (RIPK1)–dependent caspase-8 cleavage of gasdermin D (GSDMD) and inflammatory cell death (pyroptosis). A genome-wide CRISPR screen to uncover mediators of caspase-8–dependent pyroptosis identified an unexpected role of the lysosomal folliculin (FLCN)–folliculin-interacting protein 2 (FNIP2)–Rag-Ragulator supercomplex, which regulates metabolic signaling and the mechanistic target of rapamycin complex 1 (mTORC1). In response to Yersinia infection, Fas-associated death domain (FADD), RIPK1, and caspase-8 were recruited to Rag-Ragulator, causing RIPK1 phosphorylation and caspase-8 activation. Pyroptosis activation depended on Rag guanosine triphosphatase activity and lysosomal tethering of Rag-Ragulator but not mTORC1. Thus, the lysosomal metabolic regulator Rag-Ragulator instructs the inflammatory response to Yersinia.

Interaction with Sug1 enables Ipaf ubiquitination leading to caspase 8 activation and cell death

2010 ◽  
Vol 427 (1) ◽  
pp. 91-104 ◽  
Author(s):  
Yatender Kumar ◽  
Vegesna Radha ◽  
Ghanshyam Swarup
Keyword(s):  
Cell Death ◽  
Mammalian Cells ◽  
Intramolecular Interaction ◽  
Dominant Negative ◽  
26S Proteasome ◽  
Caspase 8 ◽  
Interacting Protein ◽  
Caspase 1 ◽  
Lung Carcinoma Cells ◽  
Lrr Domain

Activation of initiator caspases is dependent on interacting proteins, and Ipaf [ICE (interleukin-1β-converting enzyme)-protease activating factor] {NLRC4 [NLR (Nod-like receptor) family CARD (caspase activation and recruitment domain)-containing 4]} an inflammasome component, is involved in caspase 1 activation and apoptosis. Investigating the mechanisms of Ipaf activation, we found that the C-terminal LRR (leucine-rich repeat) domain of Ipaf, through intramolecular interaction, negatively regulates its apoptosis-inducing function. In A549 lung carcinoma cells, expression of Ac-Ipaf (LRR-domain-deleted Ipaf) induced cell death that was dependent on caspase 8, but not on caspase 1. A yeast two-hybrid screen using Ac-Ipaf as bait identified human Sug1 (suppressor of gal 1), a component of the 26S proteasome, as an interacting protein. In mammalian cells Sug1 interacts and co-localizes with Ipaf. Sug1 binds to amino acids 91–253 of Ipaf, which is also the region that the LRR domain binds to. It potentiates cell death induced by Ipaf and Ac-Ipaf, and co-expression of Sug1 and Ipaf induces caspase-8-dependent cell death. Cellular complexes formed by Ipaf and Sug1 contain caspase 8. Expression of Ac-Ipaf or co-expression of Sug1 with Ipaf results in the formation of cytoplasmic aggregates and caspase 8 activation. Sug1 co-expression enabled modification of Ipaf by ubiquitination. Tagging ubiquitin molecules to Ipaf led to aggregate formation, enhanced caspase 8 interaction and activation, resulting in induction of cell death. Using RNAi (RNA interference) and dominant-negative approaches, we have shown that cell death induced by Ac-Ipaf expression or by treatment with TNF-α (tumour necrosis factor α) or doxorubicin is dependent on Sug1. Our results suggest a role for ubiquitination of Ipaf that is enabled by its interaction with Sug1, leading to caspase 8 activation and cell death.

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