scholarly journals Heterogeneous responses to low level death receptor activation are explained by random molecular assembly of the Caspase-8 activation platform

2019 ◽  
Vol 15 (9) ◽  
pp. e1007374 ◽  
Author(s):  
Anna Matveeva ◽  
Michael Fichtner ◽  
Katherine McAllister ◽  
Christopher McCann ◽  
Marc Sturrock ◽  
...  
2010 ◽  
Vol 88 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Julie Roy ◽  
Pragathi Pallepati ◽  
Ahmed Bettaieb ◽  
Diana A. Averill-Bates

Acrolein, a highly reactive α,β-unsaturated aldehyde, is an omnipresent environmental pollutant. Chronic and acute human exposures occur through exogenous and endogenous sources, including food, vapors of overheated cooking oil, house and forest fires, cigarette smoke, and automobile exhaust. Acrolein is a toxic byproduct of lipid peroxidation, which has been implicated in pulmonary, cardiac, and neurodegenerative diseases. This study shows that p53 is an initiating factor in acrolein-induced death receptor activation during apoptosis in A549 human lung cells. Exposure of cells to acrolein (0–50 µmol/L) mainly caused apoptosis, which was manifested by execution phase events such as condensation of nuclear chromatin, phosphatidylserine externalization, and poly(ADP-ribose) polymerase (PARP) cleavage. Levels of necrosis (~5%) were low. Acrolein triggered the death receptor pathway of apoptosis, causing elevation of Fas ligand (FasL) and translocation of adaptor protein Fas-associated death domain to the plasma membrane. Acrolein caused activation of caspase-8, caspase-2, caspase-7, and the cross-talk pathway mediated by Bid cleavage. Activation of p53 and increased expression of p53-upregulated modulator of apoptosis (PUMA) occurred in response to acrolein. FasL upregulation and caspase-8 activation were decreased by p53 inhibitor pifithrin-α and antioxidant polyethylene glycol catalase. These findings increase our knowledge about the induction of cell death pathways by acrolein, which has important implications for human health.


2008 ◽  
Vol 86 (6) ◽  
pp. 521-538 ◽  
Author(s):  
Ahmed Bettaieb ◽  
Diana A. Averill-Bates

Mild temperatures such as 40 °C are physiological and occur during fevers. This study determines whether mild thermotolerance induced at 40 °C can protect HeLa cells against activation of the death receptor pathway of apoptosis by lethal hyperthermia (42–45 °C). Protein expression of heat shock proteins (Hsps) 27, 32, 60, 72, 90, and 110 was increased in thermotolerant cells (3 h, 40°C). Lethal hyperthermia (42–43 °C)  caused cell death by apoptosis, but at 45 °C there was a switch to necrosis. Mild thermotolerance protected cells against heat-induced apoptosis (Annexin V labelling). Hyperthermia induced apoptosis through generation of reactive oxygen species (ROS) and death receptor signalling. The antioxidant polyethylene glycol-catalase abrogated increased expression of Fas death ligand and caspase-8 activation in response to lethal hyperthermia (42–43 °C). Mild thermotolerance attenuated the heat induction of ROS and FasL, which were initiating events in death receptor activation and signalling. Mild thermotolerance inhibited early events in hyperthermia-induced death receptor apoptosis such as Fas-associated death domain (FADD) translocation to membranes, caspase-8 activation, and tBid translocation to mitochondria. Downstream events in apoptosis such as caspase-3 activation, cleavage of PARP and ICAD, and chromatin condensation were also diminished in thermotolerant cells. It is important to improve knowledge about adaptive responses induced by exposure to mild stresses, such as fever temperatures, which can protect cells against subsequent exposure to lethal stress.


Oncogene ◽  
2001 ◽  
Vol 20 (41) ◽  
pp. 5865-5877 ◽  
Author(s):  
Simone Fulda ◽  
Martin U Küfer ◽  
Eric Meyer ◽  
Frans van Valen ◽  
Barbara Dockhorn-Dworniczak ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marie-Anaïs Locquet ◽  
Gabriel Ichim ◽  
Joseph Bisaccia ◽  
Aurelie Dutour ◽  
Serge Lebecque ◽  
...  

AbstractIn cancer cells only, TLR3 acquires death receptor properties by efficiently triggering the extrinsic pathway of apoptosis with Caspase-8 as apical protease. Here, we demonstrate that in the absence of Caspase-8, activation of TLR3 can trigger a form of programmed cell death, which is distinct from classical apoptosis. When TLR3 was activated in the Caspase-8 negative neuroblastoma cell line SH-SY5Y, cell death was accompanied by lysosomal permeabilization. Despite caspases being activated, lysosomal permeabilization as well as cell death were not affected by blocking caspase-activity, positioning lysosomal membrane permeabilization (LMP) upstream of caspase activation. Taken together, our data suggest that LMP with its deadly consequences represents a “default” death mechanism in cancer cells, when Caspase-8 is absent and apoptosis cannot be induced.


2006 ◽  
Vol 94 (3) ◽  
pp. 398-406 ◽  
Author(s):  
E Szegezdi ◽  
S Cahill ◽  
M Meyer ◽  
M O'Dwyer ◽  
A Samali

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenhua Liu ◽  
Liangbin Gao ◽  
Peng Wang ◽  
Zhongyu Xie ◽  
Shuizhong Cen ◽  
...  

Ankylosing spondylitis (AS) is an autoimmune disease with unknown etiology. Dysregulated mesenchymal stem cells (MSCs) apoptosis may contribute to the pathogenesis of autoimmune diseases. However, apoptosis of MSCs from patients with AS (ASMSCs) has not been investigated yet. The present study aims to assess the apoptosis of bone marrow-derived ASMSCs and to investigate the underlying mechanisms of altered ASMSCs apoptosis. We successfully induced the apoptosis of ASMSCs and MSCs from healthy donors (HDMSCs) using the combination of tumor necrosis factor alpha (TNF-α) and cycloheximide (CHX). We found that ASMSCs treated with TNF-αand CHX showed higher apoptosis levels compared to HDMSCs. During apoptosis, ASMSCs expressed significantly more TRAIL-R2, which activated both the death receptor pathway and mitochondria pathway by increasing the expression of FADD, cleaved caspase-8, cytosolic cytochrome C, and cleaved caspase-3. Inhibiting TRAIL-R2 expression using shRNA eliminated the apoptosis differences between HDMSCs and ASMSCs by partially reducing ASMSCs apoptosis but minimally affecting that of HDMSCs. Furthermore, the expression of FADD, cleaved caspase-8, cytosolic cytochrome C, and cleaved caspase-3 were comparable between HDMSCs and ASMSCs after TRAIL-R2 inhibition. These results indicated that increased TRAIL-R2 expression results in enhanced ASMSCs apoptosis and may contribute to AS pathogenesis.


Author(s):  
Kanchana Suksri ◽  
Namoiy Semprasert ◽  
Mutita Junking ◽  
Suchanoot Kutpruek ◽  
Thawornchai Limjindaporn ◽  
...  

Long-term medication with dexamethasone (a synthetic glucocorticoid (GC) drug) results in hyperglycemia, or steroid-induced diabetes. Although recent studies revealed dexamethasone directly induces pancreatic β-cell apoptosis, its molecular mechanisms remain unclear. In our initial analysis of mRNA transcripts, we discovered the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway may be involved in dexamethasone-induced pancreatic β-cell apoptosis. In the present study, a mechanism of dexamethasone-induced pancreatic β-cell apoptosis through the TRAIL pathway was investigated in cultured cells and isolated mouse islets. INS-1 cells were cultured with and without dexamethasone in the presence or absence of a glucocorticoid receptor (GR) inhibitor, RU486. We found that dexamethasone induced pancreatic β-cell apoptosis in association with the upregulation of TRAIL mRNA and protein expression. Moreover, dexamethasone upregulated the TRAIL death receptor (DR5) protein but suppressed the decoy receptor (DcR1) protein. Similar findings were observed in mouse isolated islets: dexamethasone increased TRAIL and DR5 compared to that of control mice. Furthermore, dexamethasone stimulated pro-apoptotic signaling including superoxide production, caspase-8, -9, and -3 activities, NF-B, and Bax, but repressed the anti-apoptotic protein, Bcl-2. All these effects were inhibited by the GR-inhibitor, RU486. Furthermore, knock down DR5 decreased dexamethasone-induced caspase 3 activity. Caspase-8 and caspase-9 inhibitors protected pancreatic β-cells from dexamethasone-induced apoptosis. Taken together, dexamethasone induced pancreatic β-cell apoptosis by binding to the GR and inducing DR5 and TRAIL pathway.


2003 ◽  
Vol 23 (21) ◽  
pp. 7838-7848 ◽  
Author(s):  
Nerina Gnesutta ◽  
Audrey Minden

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.


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