scholarly journals Regulation of the Extrinsic Apoptotic Pathway by the Extracellular Matrix Glycoprotein EMILIN2

2007 ◽  
Vol 27 (20) ◽  
pp. 7176-7187 ◽  
Author(s):  
Maurizio Mongiat ◽  
Giovanni Ligresti ◽  
Stefano Marastoni ◽  
Erica Lorenzon ◽  
Roberto Doliana ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Survival ◽  
Three Dimensional ◽  
Death Receptor ◽  
Death Receptors ◽  
Soft Agar ◽  
Apoptotic Pathway ◽  
Signaling Complex ◽  
Extrinsic Apoptotic Pathway ◽  
Trail Receptors

ABSTRACT Elastin microfibril interface-located proteins (EMILINs) constitute a family of extracellular matrix (ECM) glycoproteins characterized by the presence of an EMI domain at the N terminus and a gC1q domain at the C terminus. EMILIN1, the archetype molecule of the family, is involved in elastogenesis and hypertension etiology, whereas the function of EMILIN2 has not been resolved. Here, we provide evidence that the expression of EMILIN2 triggers the apoptosis of different cell lines. Cell death depends on the activation of the extrinsic apoptotic pathway following EMILIN2 binding to the TRAIL receptors DR4 and, to a lesser extent, DR5. Binding is followed by receptor clustering, colocalization with lipid rafts, death-inducing signaling complex assembly, and caspase activation. The direct activation of death receptors by an ECM molecule that mimics the activity of the known death receptor ligands is novel. The knockdown of EMILIN2 increases transformed cell survival, and overexpression impairs clonogenicity in soft agar and three-dimensional growth in natural matrices due to massive apoptosis. These data demonstrate an unexpected direct and functional interaction of an ECM constituent with death receptors and discloses an additional mechanism by which ECM cues can negatively affect cell survival.

In Vitro Synergistic Anti-Tumor Activity by Targeting TRAIL-R1 and CD20 Antigen by Combining HGS-ETR1 (Agonistic Human Monoclonal Antibody to TRAIL Receptor 1) and Rituximab Monoclonal Antibody Against Non-Hodgkin’s Lymphoma Cells (NHL).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1475-1475
Author(s):  
Myron S. Czuczman ◽  
Sreeram Maddipatla ◽  
Joy Knight ◽  
Francisco J. Hernandez-Ilizaliturri
Keyword(s):  
Cell Lines ◽  
Receptor Agonist ◽  
Growth Arrest ◽  
Death Receptor ◽  
Trail Receptor ◽  
Apoptotic Pathway ◽  
Cell Growth Arrest ◽  
Trail Receptors ◽  
Anti Tumor Activity

Abstract Tumor necrosis factor-related apoptosis ligand (TRAIL) or agonist antibodies targeting specific TRAIL-receptors possess significant in vitro and in vivo anti-tumor activity. HGS-ETR1 (mapatumumab) and HGS-ETR2 are two fully human recombinant, high affinity IgG1λ mAbs targeting TRAIL-R1 (Death-receptor 4, DR-4) and TRAIL-R2 (Death-receptor 5, DR-5), respectively. TRAIL-receptor agonist mAbs trigger the extrinsic (mitochondria-independent) apoptotic pathway and enhance the anti-tumor effects of chemotherapy drugs against NHL. Combining TRAIL-receptor agonist mAbs with biological agents (e.g. rituximab) capable of activating the intrinsic (mitochondria-dependent) apoptotic pathway may result in synergistic effects against NHL. Objective: To study the biological effects of rituximab when combined with either HGS-ETR1 or HGS-ETR2. Materials and methods: A panel of NHL cell lines [Raji, SUDHL-4, SU-DHL-10, Ramos, and two rituximab resistant cell lines (RRCL), 2R and 4RH] were utilized. Expression of CD20, TRAIL-R1 and TRAIL-R2 in the NHL cells used were evaluated by flow cytometry. NHL cells were exposed to HGS-ETR1 or HGS-ETR2 followed by either rituximab, istoype control antibody or media alone. DNA synthesis and cell growth arrest were quantified by [H3] Thymidine incorporation assays at 24 and 48 hrs. Induction of apoptosis was detected by multiparameter flow cytometric analysis. For antibody-dependent cellular cytotoxicity (ADCC)/Complement mediated cytotoxicity (CMC) studies, 51Cr-labeled NHL cells were exposed to HGS-ETR1 or HGS-ETR2 (5μg/ml) +/− rituximab or isotype control antibody (10μg/ml) and peripheral blood mononuclear cells (Effector: Target ratio 40:1) or human serum, respectively. 51Cr-release was measured and the percentage of lysis was calculated. Statistical analysis of results was performed using the Chi-square test. Results: In sensitive cells in vitro exposure to HGS-ETR1 resulted in significant apoptosis (30–50%) and decrease in DNA synthesis. The combination of HGS-ETR1 and rituximab resulted in significant inhibition of cell proliferation (90% reduction) when compared to either HGS-ETR1 (60% reduction) or rituximab (5% reduction) alone at 24 and 48 hrs. In sensitive cells HGS-ETR1 induced CMC and ADCC as a single agent. No significant anti-tumor activity was observed with HGS-ETR2. The biological activity of anti-TRAIL receptors mAbs did not correlate to TRAIL-R1 or TRAIL-R2 cell surface antigen expression. Conclusions: Targeting TRAIL-R1 with HGS-ETR1 induces apoptosis, cell growth arrest and in some cell lines ADCC/CMC. The combination of HGS-ETR1 with rituximab results in significant synergistic activity (i.e. anti-proliferation) and warrants further pre-clinical and clinical evaluation in B-cell lymphomas.

scholarly journals Hypo-Expression of Flice-Inhibitory Protein and Activation of the Caspase-8 Apoptotic Pathways in the Death-Inducing Signaling Complex Due to Ischemia Induced by the Compression of the Asphyxiogenic Tool on the Skin in Hanging Cases

Diagnostics ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 938
Author(s):  
Aniello Maiese ◽  
Alessandra De Matteis ◽  
Giorgio Bolino ◽  
Emanuela Turillazzi ◽  
Paola Frati ◽  
...  
Keyword(s):  
Tertiary Structure ◽  
Active Form ◽  
Three Dimensional ◽  
Death Receptor ◽  
Cell Receptor ◽  
Control Group ◽  
Caspase 8 ◽  
Inhibitory Protein ◽  
Signaling Complex ◽  
Induced Apoptosis

The FLICE-inhibitory protein (c-FLIPL) (55 kDa) is expressed in numerous tissues and most abundantly in the kidney, skeletal muscles and heart. The c-FLIPL has a region of homology with caspase-8 at the carboxy-terminal end which allows the molecule to assume a tertiary structure similar to that of caspases-8 and -10. Consequently, c-FLIPL acts as a negative inhibitor of caspase-8, preventing the processing and subsequent release of the pro-apoptotic molecule active form. The c-FLIP plays as an inhibitor of apoptosis induced by a variety of agents, such as tumor necrosis factor (TNF), T cell receptor (TCR), TNF-related apoptosis inducing ligand (TRAIL), Fas and death receptor (DR). Increased expression of c-FLIP has been found in many human malignancies and shown to be involved in resistance to CD95/Fas and TRAIL receptor-induced apoptosis. We wanted to verify an investigative protocol using FLIP to make a differential diagnosis between skin sulcus with vitality or non-vital skin sulcus in hanged subjects and those undergoing simulated hanging (suspension of the victim after murder). The study group consisted of 21 cases who died from suicidal hanging. The control group consisted of traumatic or natural deaths, while a third group consisted of simulated hanging cases. The reactions to the Anti-FLIP Antibody (Abcam clone-8421) was scored for each section with a semi-quantitative method by means of microscopic observation carried out with confocal microscopy and three-dimensional reconstruction. The results obtained allow us to state that the skin reaction to the FLIP is extremely clear and precise, allowing a diagnosis of unequivocal vitality and a very objective differentiation with the post-mortal skin sulcus.

scholarly journals A Death Receptor-associated Anti-apoptotic Protein, BRE, Inhibits Mitochondrial Apoptotic Pathway

2004 ◽  
Vol 279 (50) ◽  
pp. 52106-52116 ◽  
Author(s):  
Qing Li ◽  
Arthur Kar-Keung Ching ◽  
Ben Chung-Lap Chan ◽  
Stephanie Ka-Yee Chow ◽  
Pak-Leong Lim ◽  
...  
Keyword(s):  
Tumor Necrosis Factor Receptor ◽  
Death Receptor ◽  
Cellular Level ◽  
Down Regulation ◽  
Apoptotic Pathway ◽  
Signaling Complex ◽  
Apoptotic Protein ◽  
Tnf Α ◽  
Receptor Ligation ◽  
Interfering Rna

BRE,brain andreproductive organ-expressed protein, was found previously to bind the intracellular juxtamembrane domain of a ubiquitous death receptor, tumor necrosis factor receptor 1 (TNF-R1), and to down-regulate TNF-α-induced activation of NF-κB. Here we show that BRE also binds to another death receptor, Fas, and upon overexpression conferred resistance to apoptosis induced by TNF-α, anti-Fas agonist antibody, cycloheximide, and a variety of stress-related stimuli. However, down-regulation of the endogenous BRE by small interfering RNA increased apoptosis to TNF-α, but nottoetoposide, indicating that the physiological antiapoptotic role of this protein is specific to death receptor-mediated apoptosis. We further demonstrate that BRE mediates antiapoptosis by inhibiting the mitochondrial apoptotic machinery but without translocation to the mitochondria or nucleus or down-regulation of the cellular level of truncated Bid. Dissociation of BRE rapidly from TNF-R1, but not from Fas, upon receptor ligation suggests that this protein interacts with the death inducing signaling complex during apoptotic induction. Increased association of BREwith phosphorylated, sumoylated, and ubiquitinated proteins after death receptor stimulation was also detected. We conclude that in contrast to the truncated Bid that integrates mitochondrial apoptosis to death receptor-triggered apoptotic cascade, BRE inhibits the integration. We propose that BRE inhibits, by ubiquitination-like activity, components in or proximal to the death-inducing signaling complexes that are necessary for activation of the mitochondria.

scholarly journals Characterisation of FADD interactome reveals novel insights into FADD recruitment and signalling at the Death Inducing Signalling Complex (DISC)

2021 ◽  
Author(s):  
Joanna L Fox ◽  
Laura S Dickens ◽  
Rebekah Jukes-Jones ◽  
Gareth J Miles ◽  
Claudia Langlais ◽  
...  
Keyword(s):  
Apoptotic Cell ◽  
Specific Binding ◽  
Affinity Purification ◽  
Death Receptor ◽  
Vital Role ◽  
Death Domain ◽  
Apoptotic Pathway ◽  
Signaling Complex ◽  
Binding Partners ◽  
Molecular Events

AbstractFas-associated death domain protein (FADD) plays a vital role in the extrinsic apoptotic pathway, where it forms an essential component of the death-inducing signaling complex (DISC). However, the precise early molecular events that facilitate recruitment of FADD to the DISC remain poorly defined. Using affinity purification and mass spectrometry we investigated the FADD interactome in untreated cells and following death receptor stimulation to identify novel FADD-interacting proteins. As expected, in death receptor-stimulated samples our analysis identified key components of the DISC such as Caspase-8. In addition, we identified novel binding partners including Transferrin Receptor 1 (TfR1) and Myosin Light Chain Kinase 2 (MYLK2) that are able to modulate FADD recruitment to the DISC and consequently downstream apoptotic signaling. TfR1 is pre-associated with FADD and recruited into the DISC; moreover, our data reveal that TfR1 is also pre-associated with the death receptors, TRAIL-R1 and TRAIL-R2, thereby functioning as a key regulator of DISC formation. In the case of MYLK2, specific binding of FADD to MYLK2 in non-apoptotic cells sequesters FADD from other DISC components ensuring aberrant apoptosis is not initiated. Furthermore, MYLK2 enzymatic activity is required to for it to translocate, in complex with FADD, to sites of DISC-mediated death receptor oligimerization. Taken together, our study highlights the important role that additional novel FADD binding partners play in the regulation of death receptor-mediated apoptotic cell death, in part by modulating FADD recruitment to the DISC.

scholarly journals Reovirus-Induced Apoptosis Is Mediated by TRAIL

2000 ◽  
Vol 74 (17) ◽  
pp. 8135-8139 ◽  
Author(s):  
Penny Clarke ◽  
Suzanne M. Meintzer ◽  
Spencer Gibson ◽  
Christian Widmann ◽  
Timothy P. Garrington ◽  
...  
Keyword(s):  
Death Receptor ◽  
Tnf Receptor ◽  
Death Domain ◽  
Apoptotic Pathway ◽  
Cellular Receptors ◽  
Trail Receptors ◽  
Infected Cells ◽  
Soluble Trail ◽  
Induced Apoptosis ◽  
Necrosis Factor

ABSTRACT Members of the tumor necrosis factor (TNF) receptor superfamily and their activating ligands transmit apoptotic signals in a variety of systems. We now show that the binding of TNF-related, apoptosis-inducing ligand (TRAIL) to its cellular receptors DR5 (TRAILR2) and DR4 (TRAILR1) mediates reovirus-induced apoptosis. Anti-TRAIL antibody and soluble TRAIL receptors block reovirus-induced apoptosis by preventing TRAIL-receptor binding. In addition, reovirus induces both TRAIL release and an increase in the expression of DR5 and DR4 in infected cells. Reovirus-induced apoptosis is also blocked following inhibition of the death receptor-associated, apoptosis-inducing molecules FADD (for FAS-associated death domain) and caspase 8. We propose that reovirus infection promotes apoptosis via the expression of DR5 and the release of TRAIL from infected cells. Virus-induced regulation of the TRAIL apoptotic pathway defines a novel mechanism for virus-induced apoptosis.

scholarly journals Edelfosine and perifosine induce selective apoptosis in multiple myeloma by recruitment of death receptors and downstream signaling molecules into lipid rafts

Blood ◽  
2006 ◽  
Vol 109 (2) ◽  
pp. 711-719 ◽  
Author(s):  
Consuelo Gajate ◽  
Faustino Mollinedo
Keyword(s):  
Multiple Myeloma ◽  
Cytochrome C ◽  
Lipid Rafts ◽  
Lipid Raft ◽  
Death Receptor ◽  
Death Receptors ◽  
Death Domain ◽  
Cytochrome C Release ◽  
Signaling Complex ◽  
Induced Apoptosis

Abstract Multiple myeloma (MM) is an incurable B-cell malignancy, requiring new therapeutic strategies. We have found that synthetic alkyl-lysophospholipids (ALPs) edelfosine and perifosine induced apoptosis in MM cell lines and patient MM cells, whereas normal B and T lymphocytes were spared. ALPs induced recruitment of Fas/CD95 death receptor, Fas-associated death domain–containing protein, and procaspase-8 into lipid rafts, leading to the formation of the death-inducing signaling complex (DISC) and apoptosis. TNF-related apoptosis-inducing ligand receptor-1/death receptor 4 (TRAIL-R1/DR4) and TRAIL-R2/DR5, as well as Bid, were also recruited into lipid rafts, linking death receptor and mitochondrial signaling pathways. ALPs induced mitochondrial cytochrome c release. Bcl-XL overexpression prevented cytochrome c release and apoptosis. A Fas/CD95-deficient MM subline expressing DR4 and DR5 was resistant to edelfosine. Fas/CD95 retrovirus transduction bestowed edelfosine sensitivity in these cells. A Fas/CD95 mutant lacking part of the intracellular domain was ineffective. Lipid raft disruption prevented ALP-induced Fas/CD95 clustering, DISC formation, and apoptosis. ALP-induced apoptosis was Fas/CD95 ligand (FasL/CD95L) independent. ALP-induced recruitment of death receptors in lipid rafts potentiated MM cell killing by FasL/CD95L and TRAIL. These data uncover a novel lipid raft–mediated therapy in MM involving concentration of death receptors in membrane rafts, with Fas/CD95 playing a major role in ALP-mediated apoptosis.

scholarly journals Cardiac extrinsic apoptotic pathway is silent in young but activated in elder mice overexpressing bovine GH: interplay with the intrinsic pathway

2011 ◽  
Vol 210 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Fausto Bogazzi ◽  
Dania Russo ◽  
Francesco Raggi ◽  
Mohammad Bohlooly-Y ◽  
Jan Tornell ◽  
...  
Keyword(s):  
Caspase 8 ◽  
Intrinsic Pathway ◽  
Extrinsic Pathway ◽  
Apoptotic Pathway ◽  
Signaling Complex ◽  
Extrinsic Apoptotic Pathway ◽  
Cardiac Apoptosis ◽  
Apoptotic Pathways ◽  
Apoptotic Effects ◽  
Active Caspase

Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.

scholarly journals Induction of Autophagy during Extracellular Matrix Detachment Promotes Cell Survival

2008 ◽  
Vol 19 (3) ◽  
pp. 797-806 ◽  
Author(s):  
Christopher Fung ◽  
Rebecca Lock ◽  
Sizhen Gao ◽  
Eduardo Salas ◽  
Jayanta Debnath
Keyword(s):  
Extracellular Matrix ◽  
Cell Death ◽  
Cell Survival ◽  
Three Dimensional ◽  
Clonogenic Survival ◽  
Mammary Epithelial ◽  
Lumen Formation ◽  
Stable Reduction ◽  
Promote Cell Death

Autophagy has been proposed to promote cell death during lumen formation in three-dimensional mammary epithelial acini because numerous autophagic vacuoles are observed in the dying central cells during morphogenesis. Because these central cells die due to extracellular matrix (ECM) deprivation (anoikis), we have directly interrogated how matrix detachment regulates autophagy. Detachment induces autophagy in both nontumorigenic epithelial lines and in primary epithelial cells. RNA interference-mediated depletion of autophagy regulators (ATGs) inhibits detachment-induced autophagy, enhances apoptosis, and reduces clonogenic recovery after anoikis. Remarkably, matrix-detached cells still exhibit autophagy when apoptosis is blocked by Bcl-2 overexpression, and ATG depletion reduces the clonogenic survival of Bcl-2–expressing cells after detachment. Finally, stable reduction of ATG5 or ATG7 in MCF-10A acini enhances luminal apoptosis during morphogenesis and fails to elicit long-term luminal filling, even when combined with apoptotic inhibition mediated by Bcl-2 overexpression. Thus, autophagy promotes epithelial cell survival during anoikis, including detached cells harboring antiapoptotic lesions.

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