scholarly journals Expression of Fas ligand by human gastric adenocarcinomas: a potential mechanism of immune escape in stomach cancer

Gut ◽  
1999 ◽  
Vol 44 (2) ◽  
pp. 156-162 ◽  
Author(s):  
M W Bennett ◽  
J O’Connell ◽  
G C O’Sullivan ◽  
D Roche ◽  
C Brady ◽  
...  
Keyword(s):  
Cell Death ◽  
Stomach Cancer ◽  
Fas Ligand ◽  
Immune Escape ◽  
Immune Privilege ◽  
Lymphoid Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Gastric Adenocarcinomas

BackgroundDespite being immunogenic, gastric cancers overcome antitumour immune responses by mechanisms that have yet to be fully elucidated. Fas ligand (FasL) is a molecule that induces Fas receptor mediated apoptosis of activated immunocytes, thereby mediating normal immune downregulatory roles including immune response termination, tolerance acquisition, and immune privilege. Colon cancer cell lines have previously been shown to express FasL and kill lymphoid cells by Fas mediated apoptosis in vitro. Many diverse tumours have since been found to express FasL suggesting that a “Fas counterattack” against antitumour immune effector cells may contribute to tumour immune escape.AimTo ascertain if human gastric tumours express FasL in vivo, as a potential mediator of immune escape in stomach cancer.SpecimensThirty paraffin wax embedded human gastric adenocarcinomas.MethodsFasL protein was detected in gastric tumours using immunohistochemistry; FasL mRNA was detected in the tumours using in situ hybridisation. Cell death was detected in situ in tumour infiltrating lymphocytes using terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL).ResultsPrevalent expression of FasL was detected in all 30 resected gastric adenocarcinomas examined. In the tumours, FasL protein and mRNA were co-localised to neoplastic gastric epithelial cells, confirming expression by the tumour cells. FasL expression was independent of tumour stage, suggesting that it may be expressed throughout gastric cancer progression. TUNEL staining disclosed a high level of cell death among lymphocytes infiltrating FasL positive areas of tumour.ConclusionsHuman gastric adenocarcinomas express the immune downregulatory molecule, FasL. The results suggest that FasL is a prevalent mediator of immune privilege in stomach cancer.

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway

2004 ◽  
Vol 287 (4) ◽  
pp. H1730-H1739 ◽  
Author(s):  
Ron Zohar ◽  
Baoqian Zhu ◽  
Peter Liu ◽  
Jaro Sodek ◽  
C. A. McCulloch
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Cardiac Fibroblasts ◽  
Chromatin Condensation ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Wild Type ◽  
Nuclear Fragmentation ◽  
A Cell

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN−/−) mice were treated in vitro with H2O2to model reperfusion injury. Within 1 h, membrane permeability to propidium iodide (PI) was increased from 5 to 60% in OPN−/−cells but was increased to only 20% in WT cells. In contrast, after 1–8 h of treatment with H2O2, the percent of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-stained cells was more than twofold higher in WT than OPN−/−cells. Electron microscopy of WT cells treated with H2O2showed chromatin condensation, nuclear fragmentation, and cytoplasmic and nuclear shrinkage, which are consistent with apoptosis. In contrast, H2O2-treated OPN−/−cardiac fibroblasts exhibited cell and nuclear swelling and membrane disruption that are indicative of cell necrosis. Treatment of OPN−/−and WT cells with a cell-permeable caspase-3 inhibitor reduced the percentage of TUNEL staining by more than fourfold in WT cells but decreased staining in OPN−/−cells by ∼30%. Although the percentage of PI-permeable WT cells was reduced threefold, the percent of PI-permeable OPN−/−cells was not altered. Restoration of OPN expression in OPN−/−fibroblasts reduced the percentage of PI-permeable cells but not TUNEL staining after H2O2treatment. Thus H2O2-induced cell death in OPN-deficient cardiac fibroblasts is mediated by a caspase-3-independent, necrotic pathway. We suggest that the increased expression of OPN in the myocardium after reperfusion may promote fibrosis by protecting cardiac fibroblasts from cell death.

Uterine epithelial expression of the tumor necrosis factor superfamily: a strategy for immune privilege during pregnancy in a true epitheliochorial placentation species

2020 ◽  
Vol 102 (4) ◽  
pp. 828-842 ◽  
Author(s):  
Inkyu Yoo ◽  
Yoon Chul Kye ◽  
Jisoo Han ◽  
Minjeong Kim ◽  
Soohyung Lee ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Necrosis Factor ◽  
Epithelial Cells ◽  
Tumor Necrosis ◽  
Fas Ligand ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Immune Privilege ◽  
Tumor Necrosis Factor Superfamily ◽  
Necrosis Factor

Abstract The maternal immune system tolerates semi-allogeneic placental tissues during pregnancy. Fas ligand (FASLG) and tumor necrosis factor superfamily 10 (TNFSF10) are known to be components of maternal immune tolerance in humans and mice. However, the role of FASLG and TNFSF10 in the tolerance process has not been studied in pigs, which form a true epitheliochorial type placenta. Thus, the present study examined the expression and function of FASLG and TNFSF10 and their receptors at the maternal-conceptus interface in pigs. The endometrium and conceptus tissues expressed FASLG and TNFSF10 and their receptor mRNAs during pregnancy in a stage-specific manner. During pregnancy, FASLG and TNFSF10 proteins were localized predominantly to endometrial luminal epithelial cells with strong signals on Day 30 to term and on Day 15, respectively, and receptors for TNFSF10 were localized to some stromal cells. Interferon-γ (IFNG) increased the expression of TNFSF10 and FAS in endometrial tissues. Co-culture of porcine endometrial epithelial cells over-expressing TNFSF10 with peripheral blood mononuclear cells yielded increased apoptotic cell death of lymphocytes and myeloid cells. In addition, many apoptotic T cells were found in the endometrium on Day 15 of pregnancy. The present study demonstrated that FASLG and TNFSF10 were expressed at the maternal-conceptus interface and conceptus-derived IFNG increased endometrial epithelial TNFSF10, which, in turn, induced apoptotic cell death of immune cells. These results suggest that endometrial epithelial FASLG and TNFSF10 may be critical for the formation of micro-environmental immune privilege at the maternal-conceptus interface for the establishment and maintenance of pregnancy in pigs.

Oxidative Stress Is Associated With Cell Death, Wall Degradation, and Increased Risk of Rupture of the Intracranial Aneurysm Wall

Neurosurgery ◽  
2012 ◽  
Vol 72 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Elisa Laaksamo ◽  
Riikka Tulamo ◽  
Arto Liiman ◽  
Marc Baumann ◽  
Robert M. Friedlander ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Caspase 9 ◽  
Tissue Samples ◽  
Aneurysm Wall ◽  
Increased Risk ◽  
Risk Of Rupture ◽  
High Oxidative Stress

Abstract BACKGROUND: The cause of rupture of intracranial aneurysms (IA) is not well understood. We previously demonstrated that loss of cells from the IA wall is associated with wall degeneration and rupture. OBJECTIVE: To investigate the mechanisms mediating cell death in the IA wall. METHODS: Snap-frozen tissue samples from aneurysm fundi were studied with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and immunostaining (14 unruptured and 20 ruptured), as well as with Western blot (12 unruptured and 12 ruptured). RESULTS: Ruptured IA walls had more TUNEL-positive cells than unruptured walls (P < .001). Few cells positive for cleaved caspase-3 were detected. Cleaved caspase-9 (intrinsic activation of apoptosis) was significantly increased in ruptured IA walls, whereas cleaved caspase-8 (extrinsic activation of apoptosis) was not detected. Increased expression of hemeoxygenase-1, a marker for oxidative stress, was associated with IA wall degeneration and rupture. CONCLUSION: Our results show that programmed cell death is activated in the IA wall via the intrinsic pathway. High oxidative stress in the IA wall is probably a significant cause of the intrinsic activation of cell death.

scholarly journals In situ DNA fragmentation during the re-establishment of desiccation tolerance in germinated seeds of Cedrela fissilis Vell.

2019 ◽  
Vol 41 (2) ◽  
pp. 244-249
Author(s):  
Tathiana Elisa Masetto ◽  
José Marcio Rocha Faria
Keyword(s):  
Cell Death ◽  
Moisture Content ◽  
Dna Fragmentation ◽  
Desiccation Tolerance ◽  
Cell Injury ◽  
Tunel Staining ◽  
Long Term Storage ◽  
Germinated Seeds

Abstract: Dehydration is a necessary procedure prior to exposing seeds to long term storage, but this is associated with metabolism-linked injury mediated by cell injury. In order to assess cellular alterations during re-establishment of desiccation tolerance (DT) in C. fissilis germinated seeds and their relation to DNA damage, we verified the occurrence of DNA fragmentation through the TUNEL test and its evidence through the cytological analyses. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. The moisture content changes during the reestablishment of the desiccation tolerance was accomplished. (DT)TdT-dUPT terminal nick-end labeling (TUNEL) was used to assess rates of cell death. TUNEL staining was performed using Click-iT-TUNEL Alexa Flour imaging assay. The TUNEL test showed a consistent DNA fragmentation in the 2 and 5 mm long radicles. Moreover, nuclear and chromosomal alterations were observed in the 5 mm meristematic root cell cycle, contributing to the identification of diagnostic markers of cell death.

Altered Signaling and Regulatory Mechanisms of Apoptosis in Focal and Segmental Glomerulosclerosis

2001 ◽  
Vol 12 (7) ◽  
pp. 1422-1433 ◽  
Author(s):  
WANSHENG WANG ◽  
ALEX TZANIDIS ◽  
MAJA DIVJAK ◽  
NAPIER MAURICE THOMSON ◽  
ALICIA NOEMI STEIN-OAKLEY
Keyword(s):  
Renal Function ◽  
Reverse Transcription ◽  
Fas Ligand ◽  
Regulatory Mechanisms ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tubulointerstitial Injury ◽  
Focal And Segmental Glomerulosclerosis ◽  
Reverse Transcription Pcr ◽  
Segmental Glomerulosclerosis

Abstract. The purpose of this study was to investigate signaling and regulatory mechanisms of apoptosis in a model of focal and segmental glomerulosclerosis. Sprague-Dawley rats received two doses of puromycin aminonucleoside (PAN) (day 0 and week 3) and a uninephrectomy (PAN model). Apoptosis was detected with the use of the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling technique. Bax, Bcl-2, Fas, and Fas ligand expression was analyzed by competitive reverse transcription-PCR. Bax, Bcl-2, and Fas mRNA were localized by in situ hybridization. Renal function was transiently impaired after the first PAN dose. After the second PAN dose, further progressive renal impairment, tubular atrophy, interstitial fibrosis, and glomerulosclerosis were evident. Eighteen percent of PAN samples demonstrated up to 4 apoptotic cells/50 glomeruli, compared with 7% of sham controls (not significant). No consistent significant change in glomerular Bax, Bcl-2, Fas, and Fas ligand mRNA was evident by reverse transcription-PCR, although focal increases in glomerular Bcl-2 mRNA were demonstrated by in situ hybridization. In the tubulointerstitium, apoptosis was increased from weeks 1 to 12 (P < 0.01 PAN versus sham), correlated to renal function and tubulointerstitial injury (P < 0.01). Total renal Bax, Fas, and Fas ligand mRNA were upregulated in the PAN model, peaking at week 17 (P < 0.01 versus sham), whereas Bcl-2 mRNA was not significantly different in PAN versus sham controls. In situ hybridization in the PAN model demonstrated prominent Bax mRNA in dilated tubules and infiltrating leukocytes. Fas mRNA signal was localized to tubular epithelial cells and leukocytes. The results suggest that altered apoptotic signaling and regulatory mechanisms contribute to the tubulointerstitial injury in this model.

scholarly journals Down-regulation of MicroRNA-21 Is Involved in the Propofol-induced Neurotoxicity Observed in Human Stem Cell–derived Neurons

2014 ◽  
Vol 121 (4) ◽  
pp. 786-800 ◽  
Author(s):  
Danielle M. Twaroski ◽  
Yasheng Yan ◽  
Jessica M. Olson ◽  
Zeljko J. Bosnjak ◽  
Xiaowen Bai
Keyword(s):  
Cell Death ◽  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Human Embryonic Stem Cell ◽  
Embryonic Stem ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Signal Transducer ◽  
Deoxyuridine Triphosphate ◽  
Transcription 3

Abstract Background: Recent studies in various animal models have suggested that anesthetics such as propofol, when administered early in life, can lead to neurotoxicity. These studies have raised significant safety concerns regarding the use of anesthetics in the pediatric population and highlight the need for a better model to study anesthetic-induced neurotoxicity in humans. Human embryonic stem cells are capable of differentiating into any cell type and represent a promising model to study mechanisms governing anesthetic-induced neurotoxicity. Methods: Cell death in human embryonic stem cell–derived neurons was assessed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling staining, and microRNA expression was assessed using quantitative reverse transcription polymerase chain reaction. miR-21 was overexpressed and knocked down using an miR-21 mimic and antagomir, respectively. Sprouty 2 was knocked down using a small interfering RNA, and the expression of the miR-21 targets of interest was assessed by Western blot. Results: Propofol dose and exposure time dependently induced significant cell death (n = 3) in the neurons and down-regulated several microRNAs, including miR-21. Overexpression of miR-21 and knockdown of Sprouty 2 attenuated the increase in terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling–positive cells following propofol exposure. In addition, miR-21 knockdown increased the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end labeling–positive cells by 30% (n = 5). Finally, activated signal transducer and activator of transcription 3 and protein kinase B (Akt) were down-regulated, and Sprouty 2 was up-regulated following propofol exposure (n = 3). Conclusions: These data suggest that (1) human embryonic stem cell–derived neurons represent a promising in vitro human model for studying anesthetic-induced neurotoxicity, (2) propofol induces cell death in human embryonic stem cell–derived neurons, and (3) the propofol-induced cell death may occur via a signal transducer and activator of transcription 3/miR-21/Sprouty 2–dependent mechanism.

Glutathione S-transferase overexpression protects against anthracycline-induced H9C2 cell death

2004 ◽  
Vol 286 (6) ◽  
pp. H2057-H2064 ◽  
Author(s):  
Thomas L'Ecuyer ◽  
Zuhair Allebban ◽  
Ronald Thomas ◽  
Richard Vander Heide
Keyword(s):  
Cell Death ◽  
Trypan Blue ◽  
Oxidant Stress ◽  
Hematologic Malignancies ◽  
Model System ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
H9c2 Cell ◽  
Significant Activity ◽  
Glutathione S Transferase

Anthracyclines (AC) are antitumor antibiotics with significant activity against solid and hematologic malignancies. One problem preventing more widespread use has been the development of cardiac toxicity. Experimental evidence supports oxidant stress as an important trigger and/or mediator of AC-induced cardiotoxicity (ACT). Therefore, reducing oxidant stress should be protective against ACT. To determine whether antioxidant protein overexpression can reduce ACT, we developed a cell culture model system using the H9C2 cardiac cell line exhibiting controlled overexpression of the α4-isoform of glutathione- S-transferase (GST). Treatment with the AC doxorubicin (DOX) produced both oncosis, manifested by an increase in the number of cells staining positive for Trypan blue, and apoptosis, indicated by the presence of positive terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. In both cases, the loss of cell viability was preceded by an AC-induced increase in fluorescence with carboxy-2′,7′-dichlorofluorescein diacetate, demonstrating the presence of high levels of reactive oxygen species (ROS). The DOX-induced increase in ROS was reduced to control levels by maximal GST overexpression. Coincident with this elimination of oxidative stress, there was a reduction in both Trypan blue and TUNEL-positive cells, indicating that GST overexpression reduced both ROS and cell death in this model system. We conclude that GST overexpression may be an important part of a protective strategy against ACT and that this model system will aid in defining steps in the pathway(s) leading to AC-induced cell death that can be therapeutically manipulated.

scholarly journals Characteristic and Otopathogenic Analysis of a Vibrio alginolyticus Strain Responsible for Chronic Otitis Externa in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Ke Zhou ◽  
Ke-yong Tian ◽  
Xin-qin Liu ◽  
Wei Liu ◽  
Xin-yu Zhang ◽  
...  
Keyword(s):  
Cell Death ◽  
Otitis Externa ◽  
Flow Cytometric Analysis ◽  
Vibrio Alginolyticus ◽  
Cell Counting ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Characteristic Analysis ◽  
Ear Infections ◽  
Ganglion Neurons

Vibrio alginolyticus, a Gram-negative rod bacterium found in marine environments, is known to cause opportunistic infections in humans, including ear infections, which can be difficult to diagnose. We investigated the microbiological and otopathogenic characteristics of a V. alginolyticus strain isolated from an ear exudate specimen obtained from a patient with chronic otitis externa to provide a basis for the future diagnosis of V. alginolyticus-associated infections. The identification of V. alginolyticus was accomplished using a combination of matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), classical biochemical identification methods, and the use of Vibrio-selective media and advanced molecular identification methodologies. Antimicrobial susceptibility testing revealed that the strain was resistant to ampicillin and sensitive to β-lactam, aminoglycosides, fluoroquinolones, and sulfonamide antibiotics. The potential otopathogenic effects of V. alginolyticus were determined through the performance of cell viability, cell apoptosis, and cell death assays in tympanic membrane (TM) keratinocytes and HEI-OC1 cells treated with V. alginolyticus-conditioned medium using cell-counting kit (CCK)-8 assay, a wound-healing migration assay, Annexin V/propidium iodide (PI) flow cytometric analysis, and terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL staining). The results indicated that the identified V. alginolyticus strain exerts cytotoxic effects on keratinocytes and HEI-OC1 cells by inhibiting cell proliferation and migration and inducing apoptosis and cell death. To evaluate the ototoxicity of V. alginolyticus, the cell density and morphological integrity of hair cells (HCs) and spiral ganglion neurons (SGNs) were analyzed after exposing cochlear organotypic explants to the bacterial supernatant, which revealed the pre-dominant susceptibility and vulnerability of HCs and SGNs in the basal cochlear region to the ototoxic insults exerted by V. alginolyticus. Our investigation highlights the challenges associated with the identification and characteristic analysis of the Vibrio strain isolated in this case and ultimately aims to increase the understanding and awareness of clinicians and microbiologists for the improved diagnosis of V. alginolyticus-associated ear infections and the recognition of its potential otopathogenic and ototoxic effects.

A vision of cell death: Fas ligand and immune privilege 10 years later

2006 ◽  
Vol 213 (1) ◽  
pp. 228-238 ◽  
Author(s):  
Thomas A. Ferguson ◽  
Thomas S. Griffith
Keyword(s):  
Cell Death ◽  
Fas Ligand ◽  
Immune Privilege
Sign in / Sign up

Export Citation Format

Share Document