scholarly journals In situ apoptotic cell labeling by the TUNEL method: improvement and evaluation on cell preparations.

1996 ◽  
Vol 44 (9) ◽  
pp. 959-968 ◽  
Author(s):  
A Negoescu ◽  
P Lorimier ◽  
F Labat-Moleur ◽  
C Drouet ◽  
C Robert ◽  
...  

TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling) is a method of choice for rapid identification and quantification of the apoptotic cell fraction in cultured cell preparations. However, TUNEL application has been restricted to a narrow spectrum of sample conditions, and only detergents have been proposed as labeling enhancers. This study was aimed at extending TUNEL to variously fixed cells and improving TUNEL sensitivity by optimized pretreatments, the specificity being assessed by reference to the apoptotic morphology. Comparative TUNEL was performed with three protocols on CEM-C7 cells, a model of glucocorticoid-induced apoptosis. Samples were submitted to six modalities of fixation and TUNEL was performed after each of the following conditions: no pretreatment; detergent permeabilization; proteolytic digestion; microwave irradiation; and a recently published combination of the latter two. The proportion of TUNEL-stained elements within the cell fraction, with and without apoptotic morphology, was quantified. Our results showed that: (a) with an adequate pretreatment, reliable TUNEL can be obtained after each fixative tested; (b) detergent was inefficient in improving sensitivity; (c) whatever the fixation, microwave pretreatment provided the best TUNEL sensitivity without notable loss of specificity; (d) under adaptive technical conditions, TUNEL can be associated with detection of various proteins by double labeling; and (e) the existence of a limited population of intensely TUNEL-positive cells that lacked apoptotic morphology contributes to the current debate about a preapoptotic state.

2015 ◽  
Vol 35 (3) ◽  
pp. 1125-1136 ◽  
Author(s):  
Chuqi Yan ◽  
Dechao Kong ◽  
Dong Ge ◽  
Yanming Zhang ◽  
Xishan Zhang ◽  
...  

Background/Aims: Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease characterised by prominent synoviocyte hyperplasia and a potential imbalance between the growth and death of fibroblast-like synoviocytes (FLS). Mitomycin C (MMC) has previously been demonstrated to inhibit fibroblast proliferation and to induce fibroblast apoptosis. However, the effects of MMC on the proliferation and apoptosis of human RA FLS and the potential mechanisms underlying its effects remain unknown. Methods: Cell viability was determined using the Cell Counting Kit-8 assay. Apoptotic cell death was analysed via Annexin V-FITC/PI double staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling. The production of intracellular reactive oxygen species (ROS) was assessed via flow cytometry, and the changes in mitochondrial membrane potential (ΔΨm) were visualized based on JC-1 staining via fluorescence microscopy. The expression of apoptosis-related proteins was determined via Western blot. Results: Treatment with MMC significantly reduced cell viability and induced apoptosis in RA FLS. Furthermore, MMC exposure was found to stimulate the production of ROS and to disrupt the ΔΨm compared to the control treatment. Moreover, MMC increased the release of mitochondrial cytochrome c, the ratio of Bax/Bcl-2, the activation of caspase-9 and caspase-3, and the subsequent cleavage of poly(ADP-ribose) polymerase. Conclusion: Our findings suggest that MMC inhibits cell proliferation and induces apoptosis in RA FLS, and the mechanism underlying this MMC-induced apoptosis may involve a mitochondrial signalling pathway.


1998 ◽  
Vol 72 (1) ◽  
pp. 823-829 ◽  
Author(s):  
Philippe Desprès ◽  
Marie-Pascale Frenkiel ◽  
Pierre-Emmanuel Ceccaldi ◽  
Claudia Duarte Dos Santos ◽  
Vincent Deubel

ABSTRACT Apoptosis has been suggested as a mechanism by which dengue (DEN) virus infection may cause neuronal cell death (P. Desprès, M. Flamand, P.-E. Ceccaldi, and V. Deubel, J. Virol. 70:4090–4096, 1996). In this study, we investigated whether apoptotic cell death occurred in the central nervous system (CNS) of neonatal mice inoculated intracerebrally with DEN virus. We showed that serial passage of a wild-type human isolate of DEN virus in mouse brains selected highly neurovirulent variants which replicated more efficiently in the CNS. Infection of newborn mice with these neurovirulent variants produced fatal encephalitis within 10 days after inoculation. Virus-induced cell death and oligonucleosomal DNA fragmentation were observed in mouse brain tissue by day 9. Infected mouse brain tissue was assayed for apoptosis by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and for virus replication by immunostaining of viral antigens and in situ hybridization. Apoptotic cell death and DEN virus replication were restricted to the neurons of the cortical and hippocampal regions. Thus, DEN virus-induced apoptosis in the CNS was a direct result of virus infection. In the murine neuronal cell line Neuro 2a, neuroadapted DEN virus variants showed infection patterns similar to those of the parental strain. However, DEN virus-induced apoptosis in these cells was more pronounced after infection with the neurovirulent variants than after infection with the parental strain.


1995 ◽  
Vol 15 (5) ◽  
pp. 728-737 ◽  
Author(s):  
J. P. MacManus ◽  
I. E. Hill ◽  
E. Preston ◽  
I. Rasquinha ◽  
T. Walker ◽  
...  

The time course of appearance of cells with DNA damage was studied in rats following transient severe forebrain ischemia. This DNA damage could be detected by in situ end-labeling on brain sections. The breaks in DNA appeared selectively by day 1 in the striatum and later in the CA1 region of the hippocampus. It was possible by double labeling to show that there was no DNA damage in astrocytes. The DNA breaks consisted of laddered DNA fragments indicative of an ordered apoptotic type of internucleosomal cleavage, which persisted without smearing for up to 7 days of reperfusion. In contrast, the DNA breaks following ischemia induced by decapitation were random and, after gel electrophoresis, consisted of smeared fragments of multiple sizes. There was some early regional cellular death, restricted to the dentate of the hippocampus, prior to the pannecrotic degeneration. It is concluded that transient forebrain ischemia leads to a type of neuronal destruction that is not random necrosis but that shares some component of the apoptotic cell death pathway.


2006 ◽  
Vol 20 (5) ◽  
pp. 1-7 ◽  
Author(s):  
Jason Sheehan ◽  
Anne Eischeid ◽  
Randi Saunders ◽  
Nader Pouratian

Object Immunosuppressive agents are believed to play a role in recovery from spinal cord injury, but the underlying mechanisms by which neuronal function is improved by these agents are poorly understood. In this study, the authors evaluate the effect of immunosuppressive medications on neurite outgrowth and cell survival after a pharmacologically induced injury. Methods Differentiated human neuroblastoma SH-SY5Y cells were injured using the calcium agonist thapsigargin. After cellular injury, neurite outgrowth in the presence or absence of immunosuppressive agents was measured. Apoptosis was quantified with the aid of a terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling assay. Neurite outgrowth was severely restricted following thapsigargin injury. Outgrowth was potentiated, however, by the addition of concentrations of 1 and 10 μM cyclosporin A in a dose-dependent fashion. Similarly, addition of 10 nM FK506 increased the percentage of neurites in the 20- to 40-micron range. A low dose (1 μM) of dexamethasone did not have a significant effect on neurite outgrowth, but a higher dose (10 μM) increased the percentage of neurites in the 10- to 45-micron range. These agents also lessened the degree of thapsigargin-induced apoptosis. Conclusions Immunosuppressive agents such as cyclosporin A, FK506, and dexamethasone can potentiate neurite outgrowth and protect against apoptotic cell death in a human postmitotic neuronal cell line. Such effects may have implications for lessening neuronal injury after neurotrauma, stroke, or neurodegeneration.


2003 ◽  
Vol 371 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Shasi V. KALIVENDI ◽  
Srigiridhar KOTAMRAJU ◽  
Sonya CUNNINGHAM ◽  
Tiesong SHANG ◽  
Cecilia J. HILLARD ◽  
...  

1-Methyl-4-phenylpyridinium (MPP+) is a neurotoxin used in cellular models of Parkinson's Disease. Although intracellular iron plays a crucial role in MPP+-induced apoptosis, the molecular signalling mechanisms linking iron, reactive oxygen species (ROS) and apoptosis are still unknown. We investigated these aspects using cerebellar granule neurons (CGNs) and human SH-SY5Y neuroblastoma cells. MPP+ enhanced caspase 3 activity after 24h with significant increases as early as 12h after treatment of cells. Pre-treatment of CGNs and neuroblastoma cells with the metalloporphyrin antioxidant enzyme mimic, Fe(III)tetrakis(4-benzoic acid)porphyrin (FeTBAP), completely prevented the MPP+-induced caspase 3 activity as did overexpression of glutathione peroxidase (GPx1) and pre-treatment with a lipophilic, cell-permeable iron chelator [N,N′-bis-(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid, HBED]. MPP+ treatment increased the number of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labelling)-positive cells which was completely blocked by pre-treatment with FeTBAP. MPP+ treatment significantly decreased the aconitase and mitochondrial complex I activities; pre-treatment with FeTBAP, HBED and GPx1 overexpression reversed this effect. MPP+ treatment increased the intracellular oxidative stress by 2—3-fold, as determined by oxidation of dichlorodihydrofluorescein and dihydroethidium (hydroethidine). These effects were reversed by pre-treatment of cells with FeTBAP and HBED and by GPx1 overexpression. MPP+-treatment enhanced the cell-surface transferrin receptor (TfR) expression, suggesting a role for TfR-induced iron uptake in MPP+ toxicity. Treatment of cells with anti-TfR antibody (IgA class) inhibited MPP+-induced caspase activation. Inhibition of nitric oxide synthase activity did not affect caspase 3 activity, apoptotic cell death or ROS generation by MPP+. Overall, these results suggest that MPP+-induced cell death in CGNs and neuroblastoma cells proceeds via apoptosis and involves mitochondrial release of ROS and TfR-dependent iron.


2000 ◽  
Vol 278 (5) ◽  
pp. C982-C988 ◽  
Author(s):  
Roni Levy ◽  
Steven D. Smith ◽  
Kala Chandler ◽  
Yoel Sadovsky ◽  
D. Michael Nelson

Preeclampsia and fetal growth restriction are associated with placental hypoperfusion and villous hypoxia. The villous response to this environment includes diminished trophoblast differentiation and enhanced apoptosis. We tested the hypothesis that hypoxia induces apoptosis in cultured trophoblasts, and that epidermal growth factor (EGF), an enhancer of trophoblast differentiation, diminishes hypoxia-induced apoptosis. Trophoblasts isolated from placentas of term-uncomplicated human pregnancies were cultured up to 72 h in standard ([Formula: see text]= 120 mmHg) or hypoxic ([Formula: see text] < 15 mmHg) conditions. Exposure to hypoxia for 24 h markedly enhanced trophoblast apoptosis as determined by DNA laddering, internucleosomal in situ DNA fragmentation, and histomorphology, as well as by the reversibility of the apoptotic process with a caspase inhibitor. Apoptosis was accompanied by increased expression of p53 and Bax and decreased expression of Bcl-2. Addition of EGF to cultured trophoblasts or exposure of more differentiated trophoblasts to hypoxia significantly lowered the level of apoptosis. We conclude that hypoxia enhances apoptosis in cultured trophoblasts by a mechanism that involves an increase in p53 and Bax expression. EGF and enhancement of cell differentiation protect against hypoxic-induced apoptosis.


2002 ◽  
Vol 282 (3) ◽  
pp. L448-L456 ◽  
Author(s):  
Juan Sanchez-Esteban ◽  
Yulian Wang ◽  
Lawrence A. Cicchiello ◽  
Lewis P. Rubin

Development of the pulmonary air sacs is crucial for extrauterine survival. Late fetal lung development is characterized by a thinning of the mesenchyme, which brings pneumocytes and endothelial cells into apposition. We hypothesized that mechanical stretch, simulating fetal breathing movements, plays an important role in this remodeling process. Using a Flexercell Strain Unit, we analyzed the effects of intermittent stretch on cell proliferation and apoptosis activation in fibroblasts isolated from fetal rat lungs during late development. On day 19, intermittent stretch increased cells in G0/G1 by 22% ( P = 0.001) and decreased in S phase by 50% ( P = 0.003) compared with unstretched controls. Cell proliferation analyzed by 5-bromo-2′-deoxyuridine incorporation showed a similar magnitude of cell cycle arrest ( P = 0.04). At this same gestational age, stretch induced apoptosis by two- to threefold over controls, assayed by DNA flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick-end labeling, and caspase-3 activation. These results indicate that mechanical stretch of fibroblasts isolated during the canalicular stage inhibits cell cycle progression and activates apoptosis. These findings are cotemporal with the mesenchymal thinning that normally occurs in situ.


2004 ◽  
Vol 32 (03) ◽  
pp. 377-387 ◽  
Author(s):  
Hyung-Jin Kim ◽  
Seon Il Jang ◽  
Young-Jun Kim ◽  
Hyun-Ock Pae ◽  
Hae-Young Won ◽  
...  

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.


2009 ◽  
Vol 55 (4) ◽  
pp. 465-472 ◽  
Author(s):  
Ryohei Ueno

Fluorescent in situ hybridization (FISH) using taxon-specific, rRNA-targeted oligonucleotide probes is one of the most powerful tools for the rapid identification of harmful microorganisms. However, eukaryotic algal cells do not always allow FISH probes to permeate over their cell walls. Members of the pathogenic micro-algal genus Prototheca are characterized by their distinctive cell-wall component, sporopollenin, an extremely tough biopolymer that resists acid and alkaline hydrolysis, enzyme attack, and acetolysis. To our knowledge, there has been no report of the successful permeation by the oligonucleotide probes over the cell walls of unicellular green micro-algae, which contain sporopollenin. The DNA probes passed through the cell wall of Prototheca wickerhamii after treating the algal cells with cetyltrimethylammonium bromide (CTAB). Most cells in the middle logarithmic growth phase culture fluoresced when hybridized with the rRNA-targeted universal probe for eukaryotes, though individual cells included in this culture differed in the level of cell-wall vulnerability to attack by the polysaccharide-degrading enzyme, thus reflecting the different stages of the life cycle. This is the first report regarding the visualization of sporopollenin-containing, green micro-algal cells by FISH.


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