scholarly journals Staurosporine-induced programmed cell death in Blastocystis occurs independently of caspases and cathepsins and is augmented by calpain inhibition

Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1284-1293 ◽  
Author(s):  
Jing Yin ◽  
Josephine Howe ◽  
Kevin S. W. Tan
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Dna Fragmentation ◽  
Mammalian Cells ◽  
Membrane Integrity ◽  
Protozoan Parasite ◽  
Cysteine Protease Inhibitor ◽  
Nuclear Condensation ◽  
Induced Apoptosis ◽  
Mitochondrial Transition Pore

Previous studies have shown that the protozoan parasite Blastocystis exhibits apoptotic features with caspase-like activity upon exposure to a cytotoxic monoclonal antibody or the anti-parasitic drug metronidazole. The present study reports that staurosporine (STS), a common apoptosis inducer in mammalian cells, also induces cytoplasmic and nuclear features of apoptosis in Blastocystis, including cell shrinkage, phosphatidylserine (PS) externalization, maintenance of plasma membrane integrity, extensive cytoplasmic vacuolation, nuclear condensation and DNA fragmentation. STS-induced PS exposure and DNA fragmentation were abolished by the mitochondrial transition pore blocker cyclosporine A and significantly inhibited by the broad-range cysteine protease inhibitor iodoacetamide. Interestingly, the apoptosis phenotype was insensitive to inhibitors of caspases and cathepsins B and L, while calpain-specific inhibitors augmented the STS-induced apoptosis response. While the identities of the proteases responsible for STS-induced apoptosis warrant further investigation, these findings demonstrate that programmed cell death in Blastocystis is complex and regulated by multiple mediators.

scholarly journals T-2 mycotoxin induced apoptosis in broiler’s liver tissue

2018 ◽  
Vol 27 (1) ◽  
pp. 9-16
Author(s):  
Piret Hussar ◽  
Tõnu Järveots ◽  
Lazo Pendovski ◽  
Katerina Blagoevska ◽  
Trpe Ristoski ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Liver Tissue ◽  
Immunohistochemical Staining ◽  
Mammalian Cells ◽  
Gallus Domesticus ◽  
Gallus Gallus Domesticus ◽  
Histopathological Changes ◽  
Induced Apoptosis ◽  
Multicellular Organisms

Apoptosis is a process of programmed cell death that occurs in multicellular organisms. As T-2 toxin is known to induce apoptosis in mammalian cells, the aim of the present experiment was to study the toxic effect of T-2 on chicken liver tissue using apoptosis-related antibodies p21 and p53 which are involved in the p53/p21-mediated apoptotic signalling pathway. The experiment was conducted on fourteen 40-day-old broilers (Gallus gallus domesticus) who were divided into control and T-2 toxin groups. For the T-2 toxin group, T-2 toxin (Sigma, Germany) was dissolved in water and given per os for three consecutive days. The material of the liver was taken 24 hours after the last application. The specimens were fixed with 10% formalin and embedded into paraffin; slices 5 μm in thickness were cut followed by immunohistochemical staining with polyclonal primary antibodies p21 and p53 (Abcam, UK) according to the manufacturer’s guidelines (IHC kit, Abcam, UK). Strong expression of p21 and p53 found in hepatocytes, endotheliocytes and around blood vessels together with large tissue destructions in T-2 toxin group birds’ liver indicates apoptosis and histopathological changes in liver tissue during T-2 mycotoxicosis.

scholarly journals Progesterone induces apoptosis of insulin-secreting cells: insights into the molecular mechanism

2014 ◽  
Vol 221 (2) ◽  
pp. 273-284 ◽  
Author(s):  
V A Nunes ◽  
E P Portioli-Sanches ◽  
M P Rosim ◽  
M S Araujo ◽  
P Praxedes-Garcia ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Dna Fragmentation ◽  
Islet Cells ◽  
Membrane Integrity ◽  
Reactive Species ◽  
Β Cells ◽  
Β Cell ◽  
Induced Apoptosis ◽  
Stress Dependent

Progesterone has been associated with the development of gestational diabetes (GD) due to the enhancement of insulin resistance. As β-cell apoptosis participates in type 1 and type 2 diabetes pathophysiology, we proposed the hypothesis that progesterone might contribute to the development of GD through a mechanism that also involves β-cell death. To address this question, RINm5F insulin-producing cells were incubated with progesterone (25–100 μM), in the presence or absence of α-tocopherol (40 μM). After 24 or 48 h, membrane integrity and DNA fragmentation were analyzed by flow cytometry. Caspase activity was used to identify the mode of cell death. The involvement of endoplasmic reticulum stress in the action of progesterone was investigated by western blotting. Oxidative stress was measured by 2',7'-dichlorofluorescein diacetate (DCFDA) oxidation. Isolated rat islets were used in similar experiments in order to confirm the effect of progesterone in primary β-cells. Incubation of RINm5F cells with progesterone increased the number of cells with loss of membrane integrity and DNA fragmentation. Progesterone induced generation of reactive species. Pre-incubation with α-tocopherol attenuated progesterone-induced apoptosis. Western blot analyses revealed increased expression of CREB2 and CHOP in progesterone-treated cells. Progesterone caused apoptotic death of rat islet cells and enhanced generation of reactive species. Our results show that progesterone can be toxic to pancreatic β-cells through an oxidative-stress-dependent mechanism that induces apoptosis. This effect may contribute to the development of GD during pregnancy, particularly under conditions that require administration of pharmacological doses of this hormone.

scholarly journals Hydrogen peroxide induces apoptosis-like death in Entamoeba histolytica trophozoites

Microbiology ◽  
2010 ◽  
Vol 156 (7) ◽  
pp. 1926-1941 ◽  
Author(s):  
Nilay Nandi ◽  
Abhik Sen ◽  
Rajdeep Banerjee ◽  
Sudeep Kumar ◽  
Vikash Kumar ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Entamoeba Histolytica ◽  
Membrane Integrity ◽  
Morphological Characteristics ◽  
Cysteine Proteases ◽  
Cysteine Protease Inhibitor ◽  
Nuclear Condensation ◽  
Outer Leaflet ◽  
Intracellular Ca ◽  
Multicellular Organisms

Programmed cell death (PCD) is an essential process in the growth and development of multicellular organisms. However, accumulating evidence indicates that unicellular eukaryotes can also undergo PCD with apoptosis-like features. This study demonstrates that after exposure to 0.8 mM H2O2 for 9 h Entamoeba histolytica presents morphological and biochemical evidence of apoptosis-like death. Morphological characteristics of apoptosis-like death including DNA fragmentation, increased vacuolization, nuclear condensation and cell rounding were observed for H2O2-exposed trophozoites with preservation of membrane integrity. Biochemical alteration in ion fluxes is also a key feature in PCD, and H2O2-exposed trophozoites showed overproduction of reactive oxygen species, increased cytosolic Ca2+ and decreased intracellular pH. Phosphatidylserine was also found to be expressed in the outer leaflet of the plasma membrane of the H2O2-treated trophozoites. Pretreatment with the cysteine protease inhibitor E-64d, the extracellular and intracellular Ca2+ chelators EGTA and BAPTA/AM, and the Ca2+ influx inhibitor verapamil prior to H2O2 exposure abolished DNA fragmentation. The oxidatively stressed trophozoites also showed an increased calpain activity, indicating involvement of Ca2+-dependent calpain-like cysteine proteases in PCD of E. histolytica. A homogeneous caspase assay showed no significant caspase activity, and administration of caspase 1 inhibitor also did not prevent the death phenotype for the oxidatively stressed trophozoites, indicating a caspase-independent apoptosis-like death. Our observations clearly demonstrate that there is a distinct calpain-dependent but caspase-independent pathway for apoptosis-like death in oxidatively stressed E. histolytica trophozoites.

Programmed cell death in a human intestinal parasite, Blastocystis hominis

Parasitology ◽  
2001 ◽  
Vol 123 (3) ◽  
pp. 235-246 ◽  
Author(s):  
A. M. A. NASIRUDEEN ◽  
K. S. W. TAN ◽  
M. SINGH ◽  
E. H. YAP
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Light And Electron Microscopy ◽  
Membrane Integrity ◽  
Blastocystis Hominis ◽  
Intestinal Protozoan ◽  
Nuclear Condensation ◽  
Cellular Machinery ◽  
Multicellular Organisms

Although programmed cell death (PCD) has been associated with multicellular organisms, there have been more reports of its presence in some protozoans. Our study shows the existence of PCD in an intestinal protozoan, Blastocystis hominis. Light and electron microscopy, biochemical and flow cytometry studies showed apoptosis-like death in B. hominis cells exposed to a cytotoxic monoclonal antibody (MAb 1D5). B. hominis cells displayed key morphological and biochemical features of apoptosis, namely, nuclear condensation and in situ fragmentation, reduced cytoplasmic volume, some externalization of phosphatidylserine and maintenance of plasma membrane integrity. No oligonucleosomal DNA laddering was observed in gel electrophoresis. This study supports earlier observations that the cellular machinery that is required to carry out PCD may have existed before the advent of multicellularity. Our study also ascribes a novel function for the B. hominis central vacuole in apoptosis; it acts as a repository where apoptotic bodies are stored before being released into the extracellular space.

scholarly journals Extracellular ATP as a trigger for apoptosis or programmed cell death.

1991 ◽  
Vol 112 (2) ◽  
pp. 279-288 ◽  
Author(s):  
L M Zheng ◽  
A Zychlinsky ◽  
C C Liu ◽  
D M Ojcius ◽  
J D Young
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Dna Fragmentation ◽  
Morphological Changes ◽  
Cell Lysis ◽  
Extracellular Atp ◽  
51Cr Release ◽  
Calmodulin Antagonist ◽  
Induced Apoptosis ◽  
Gamma S

Extracellular ATP is shown here to induce programmed cell death (or apoptosis) in thymocytes and certain tumor cell lines. EM studies indicate that the ATP-induced death of thymocytes and susceptible tumor cells follows morphological changes usually associated with glucocorticoid-induced apoptosis of thymocytes. These changes include condensation of chromatin, blebbing of the cell surface, and breakdown of the nucleus. Cytotoxicity assays using double-labeled cells show that ATP-mediated cell lysis is accompanied by fragmentation of the target cell DNA. DNA fragmentation can be set off by ATP but not the nonhydrolysable analogue ATP gamma S nor other nucleoside-5'-triphosphates. ATP-induced DNA fragmentation but not ATP-induced 51Cr release can be blocked in cells pretreated with inhibitors of protein or RNA synthesis or the endonuclease inhibitor, zinc; whereas pretreatment with calmidazolium, a potent calmodulin antagonist, blocks both DNA fragmentation and 51Cr release. The biochemical and morphological changes caused by ATP are preceded by a rapid increase in the cytoplasmic calcium of the susceptible cell. Calcium fluxes by themselves, however, are not sufficient to cause apoptosis, as the pore-forming protein, perforin, causes cell lysis without DNA fragmentation or the morphological changes associated with apoptosis. Taken together, these results indicate that ATP can cause cell death through two independent mechanisms, one of which, requiring an active participation on the part of the cell, takes place through apoptosis.

BH3-only proteins are essential initiators of programmed cell death and stress-induced apoptosis in normal and cancer cells

2008 ◽  
Vol 6 (9) ◽  
pp. 6
Author(s):  
A. Strasser ◽  
A. Villunger ◽  
P. Bouillet ◽  
E.M. Michalak ◽  
L.A. O'Reilly ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Cancer Cells ◽  
Induced Apoptosis

Mechanisms of death induced by cisplatin in proximal tubular epithelial cells: apoptosis vs. necrosis

1996 ◽  
Vol 270 (4) ◽  
pp. F700-F708 ◽  
Author(s):  
W. Lieberthal ◽  
V. Triaca ◽  
J. Levine
Keyword(s):  
Cell Death ◽  
Dna Cleavage ◽  
Primary Cultures ◽  
Cell Monolayer ◽  
Membrane Integrity ◽  
Ladder Pattern ◽  
Proximal Tubular Epithelial Cells ◽  
Proximal Tubular ◽  
High Concentrations ◽  
Induced Apoptosis

We have examined the mechanisms of cell death induced by cisplatin in primary cultures of mouse proximal tubular cells. High concentrations of cisplatin (800 microM) led to necrotic cell death over a few hours. Much lower concentrations of cisplatin (8 microM) led to apoptosis, which caused loss of the cell monolayer over several days. Necrosis was characterized by a cytosolic swelling and early loss of plasma membrane integrity. In contrast, early features of cells undergoing apoptosis included cell shrinkage and loss of attachment to the monolayers. Nuclear chromatin became condensed and fragmented in apoptosing cells. These features were absent in necrotic cells. DNA electrophoresis of cells exposed to 800 microM cisplatin yielded a "smear" pattern, due to random DNA degradation. In contrast, the DNA of apoptosing cells demonstrated a "ladder" pattern resulting from internucleosomal DNA cleavage. Antioxidants delayed cisplatin-induced apoptosis but not necrosis. Thus the mechanism of cell death induced by cisplatin is concentration dependent. Reactive oxygen species play a role in mediating apoptosis but not necrosis induced by cisplatin.

Metronidazole induces programmed cell death in the protozoan parasite Blastocystis hominis

Microbiology ◽  
2004 ◽  
Vol 150 (1) ◽  
pp. 33-43 ◽  
Author(s):  
A. M. A. Nasirudeen ◽  
Yap Eu Hian ◽  
Mulkit Singh ◽  
Kevin S. W. Tan
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Protozoan Parasite ◽  
Blastocystis Hominis

Programmed cell death during Drosophila embryogenesis

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 29-43 ◽  
Author(s):  
J.M. Abrams ◽  
K. White ◽  
L.I. Fessler ◽  
H. Steller
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Acridine Orange ◽  
Nile Blue ◽  
Molecular Genetic ◽  
Blue Staining ◽  
Nuclear Condensation ◽  
The Central Nervous System ◽  
Ultrastructural Appearance ◽  
Dying Cells

The deliberate and orderly removal of cells by programmed cell death is a common phenomenon during the development of metazoan animals. We have examined the distribution and ultrastructural appearance of cell deaths that occur during embryogenesis in Drosophila melanogaster. A large number of cells die during embryonic development in Drosophila. These cells display ultrastructural features that resemble apoptosis observed in vertebrate systems, including nuclear condensation, fragmentation and engulfment by macrophages. Programmed cell deaths can be rapidly and reliably visualized in living wild-type and mutant Drosophila embryos using the vital dyes acridine orange or nile blue. Acridine orange appears to selectively stain apoptotic forms of death in these preparations, since cells undergoing necrotic deaths were not significantly labelled. Likewise, toluidine blue staining of fixed tissues resulted in highly specific labelling of apoptotic cells, indicating that apoptosis leads to specific biochemical changes responsible for the selective affinity to these dyes. Cell death begins at stage 11 (approximately 7 hours) of embryogenesis and thereafter becomes widespread, affecting many different tissues and regions of the embryo. Although the distribution of dying cells changes drastically over time, the overall pattern of cell death is highly reproducible for any given developmental stage. Detailed analysis of cell death in the central nervous system of stage 16 embryos (13-16 hours) revealed asymmetries in the exact number and position of dying cells on either side of the midline, suggesting that the decision to die may not be strictly predetermined at this stage. This work provides the basis for further molecular genetic studies on the control and execution of programmed cell death in Drosophila.

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