scholarly journals Regulation of membrane release in apoptosis

1998 ◽  
Vol 334 (2) ◽  
pp. 479-485 ◽  
Author(s):  
Jiandi ZHANG ◽  
Timothy A. DRISCOLL ◽  
Yusuf A. HANNUN ◽  
Lina M. OBEID
Keyword(s):  
Cell Death ◽  
Membrane Lipids ◽  
Morphological Changes ◽  
Membrane Vesicles ◽  
Heterogeneous Population ◽  
Apoptotic Bodies ◽  
Fundamental Process ◽  
Release Assay ◽  
Lymphoid Cell Lines

Apoptosis is a fundamental process of cell regulation whereby cells execute one or more biochemical programs leading to cell death. Several mechanisms have been evaluated and suggested to play roles in the regulation of apoptosis, including the activation of phospholipase A2 (PLA2), usually measured as release of 3H-labelled arachidonic acid (AA) from prelabelled cells. The current study was aimed at examining the role of PLA2 in regulating apoptosis in response to several inducers (such as vincristine and etoposide) in lymphoid cell lines. Cells were labelled with [3H]fatty acids and the released radioactivity was characterized. These studies indicated that the AA release assay did not reflect release of non-esterified fatty acid via activation of the PLA2 pathway. Rather, studies using TLC and electron microscopy showed that AA release reflected a previously unsuspected shedding of a heterogeneous population of membrane vesicles and fragments, probably as components of apoptotic bodies. Further studies demonstrated that this process is an integral part of apoptosis. Overexpression of Bcl-2 or the addition of caspase peptide inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethane prevented the characteristic morphological changes of cell death, and completely inhibited the release of membrane vesicles and fragments. On the other hand, release of membrane vesicles and fragments was caused by various inducers of apoptosis, as measured by release of either 3H-labelled AA or palmitic acid. Thus the present study demonstrates that the release of membrane lipids during apoptosis defines a new assay for apoptosis and has allowed the investigation of the mechanisms regulating formation of apoptotic bodies.

scholarly journals Inhibition of Caspases Inhibits the Release of Apoptotic Bodies: Bcl-2 Inhibits the Initiation of Formation of Apoptotic Bodies in Chemotherapeutic Agent-induced Apoptosis

1999 ◽  
Vol 145 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Jiandi Zhang ◽  
Mary C. Reedy ◽  
Yusuf A. Hannun ◽  
Lina M. Obeid
Keyword(s):  
Cell Death ◽  
Chemotherapeutic Agent ◽  
Chromatin Condensation ◽  
Membrane Lipid ◽  
Lymphoid Cells ◽  
Parp Cleavage ◽  
Apoptotic Bodies ◽  
Normal Morphology ◽  
Release Assay ◽  
Induced Apoptosis

During apoptosis, the cell actively dismantles itself and reduces cell size by the formation and pinching off of portions of cytoplasm and nucleus as “apoptotic bodies.” We have combined our previously established quantitative assay relating the amount of release of [3H]-membrane lipid to the degree of apoptosis with electron microscopy (EM) at a series of timepoints to study apoptosis of lymphoid cells exposed to vincristine or etoposide. We find that the [3H]-membrane lipid release assay correlates well with EM studies showing the formation and release of apoptotic bodies and cell death, and both processes are regulated in parallel by inducers or inhibitors of apoptosis. Overexpression of Bcl-2 or inhibition of caspases by DEVD inhibited equally well the activation of caspases as indicated by PARP cleavage. They also inhibited [3H]-membrane lipid release and release of apoptotic bodies. EM showed that cells overexpressing Bcl-2 displayed near-normal morphology and viability in response to vincristine or etoposide. In contrast, DEVD did not prevent cell death. Although DEVD inhibited the chromatin condensation, PARP cleavage, release of apoptotic bodies, and release of labeled lipid, DEVD-treated cells showed accumulation of heterogeneous vesicles trapped in the condensed cytoplasm. These results suggest that inhibition of caspases arrested the maturation and release of apoptotic bodies. Our results also imply that Bcl-2 regulates processes in addition to caspase activation.

scholarly journals Apoptosis and apoptotic body: disease message and therapeutic target potentials

2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Xuebo Xu ◽  
Yueyang Lai ◽  
Zi-Chun Hua
Keyword(s):  
Cell Death ◽  
Recombinant Proteins ◽  
Inflammatory Responses ◽  
Apoptotic Bodies ◽  
Apoptotic Body ◽  
Fundamental Process ◽  
Therapeutic Measures ◽  
Membrane Bound ◽  
Dying Cells ◽  
Review Current

AbstractApoptosis is widely known as programmed cell death eliciting no inflammatory responses. The intricacy of apoptosis has been a focus of an array of researches, accumulating a wealth of knowledge which led to not only a better understanding of the fundamental process, but also potent therapies of diseases. The classic intrinsic and extrinsic signaling pathways of apoptosis, along with regulatory factors have been well delineated. Drugs and therapeutic measures designed based on current understanding of apoptosis have long been employed. Small-molecule apoptosis inducers have been clinically used for eliminating morbid cells and therefore treating diseases, such as cancer. Biologics with improved apoptotic efficacy and selectivity, such as recombinant proteins and antibodies, are being extensively researched and some have been approved by the FDA. Apoptosis also produces membrane-bound vesicles derived from disassembly of apoptotic cells, now known as apoptotic bodies (ApoBDs). These little sealed sacs containing information as well as substances from dying cells were previously regarded as garbage bags until they were discovered to be capable of delivering useful materials to healthy recipient cells (e.g., autoantigens). In this review, current understandings and knowledge of apoptosis were summarized and discussed with a focus on apoptosis-related therapeutic applications and ApoBDs.

scholarly journals Effect of Staurosporine in the Morphology and Viability of Cerebellar Astrocytes: Role of Reactive Oxygen Species and NADPH Oxidase

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Mauricio Olguín-Albuerne ◽  
Guadalupe Domínguez ◽  
Julio Morán
Keyword(s):  
Cell Death ◽  
Nadph Oxidase ◽  
Morphological Changes ◽  
Critical Factor ◽  
Cytoskeletal Proteins ◽  
Ros Production ◽  
Oxygen Species ◽  
Morphological Alterations ◽  
Cerebellar Astrocytes

Cell death implies morphological changes that may contribute to the progression of this process. In astrocytes, the mechanisms involving the cytoskeletal changes during cell death are not well explored. Although NADPH oxidase (NOX) has been described as being a critical factor in the production of ROS, not much information is available about the participation of NOX-derived ROS in the cell death of astrocytes and their role in the alterations of the cytoskeleton during the death of astrocytes. In this study, we have evaluated the participation of ROS in the death of cultured cerebellar astrocytes using staurosporine (St) as death inductor. We found that astrocytes express NOX1, NOX2, and NOX4. Also, St induced an early ROS production and NOX activation that participate in the death of astrocytes. These findings suggest that ROS produced by St is generated through NOX1 and NOX4. Finally, we showed that the reorganization of tubulin and actin induced by St is ROS independent and that St did not change the level of expression of these cytoskeletal proteins. We conclude that ROS produced by a NOX is required for cell death in astrocytes, but not for the morphological alterations induced by St.

Functional Validation of DownRegulated MicroRNAs in HeLa Cells Treated with Polyalthia longifolia Leaf Extract Using Different Microscopic Approaches: A Morphological Alteration-Based Validation

2019 ◽  
Vol 25 (05) ◽  
pp. 1263-1272 ◽  
Author(s):  
Shanmugapriya ◽  
Soundararajan Vijayarathna ◽  
Sreenivasan Sasidharan
Keyword(s):  
Cell Death ◽  
Electron Microscope ◽  
Hela Cells ◽  
Leaf Extract ◽  
Apoptotic Cell ◽  
Morphological Changes ◽  
Apoptotic Cell Death ◽  
Morphological Alteration ◽  
Polyalthia Longifolia

AbstractSeveral microscopy methods have been developed to assess the morphological changes in cells in the investigations of the mode of cell death in response to a stimulus. Our recent finding on the treatment of the IC50 concentration (26.67 μg/mL) of Polyalthia longifolia leaf extract indicated the induction of apoptotic cell death via the regulation of miRNA in HeLa cells. Hence, the current study was conducted to validate the function of these downregulated microRNAs in P. longifolia-treated HeLa cells using microscopic approaches. These include scanning electron microscope (SEM), transmission electron microscope (TEM), and acridine orange/propidium iodide (AO/PI)-based fluorescent microscopy techniques by observing the morphological alterations to cells after transfection with mimic miRNA. Interestingly, the morphological changes observed in this study demonstrated the apoptotic hallmarks, for instance, cell blebbing, cell shrinkage, cytoplasmic and nuclear condensation, vacuolization, cytoplasmic extrusion, and the formation of apoptotic bodies, which proved the role of dysregulated miRNAs in apoptotic HeLa cell death after treatment with the P. longifolia leaf extract. Conclusively, the current study proved the crucial role of downregulated miR-484 and miR-221-5p in the induction of apoptotic cell death in P. longifolia-treated HeLa cells using three approaches—SEM, TEM, and AO/PI-based fluorescent microscope.

The role of Golgi reassembly and stacking protein 65 phosphorylation in H2O2-induced cell death and Golgi morphological changes

2016 ◽  
Vol 49 (4) ◽  
pp. 217-223 ◽  
Author(s):  
Guang Ji ◽  
Weiwei Zhang ◽  
Moyuan Quan ◽  
Yang Chen ◽  
Hui Qu ◽  
...  
Keyword(s):  
Cell Death ◽  
Morphological Changes

scholarly journals A Novel Role of Listeria monocytogenes Membrane Vesicles in Inhibition of Autophagy and Cell Death

2017 ◽  
Vol 7 ◽  
Author(s):  
Svitlana Vdovikova ◽  
Morten Luhr ◽  
Paula Szalai ◽  
Lars Nygård Skalman ◽  
Monika K. Francis ◽  
...  
Keyword(s):  
Cell Death ◽  
Listeria Monocytogenes ◽  
Membrane Vesicles

scholarly journals Inhibiting the Mitochondrial Fission Machinery Does Not Prevent Bax/Bak-Dependent Apoptosis

2006 ◽  
Vol 26 (20) ◽  
pp. 7397-7408 ◽  
Author(s):  
Philippe A. Parone ◽  
Dominic I. James ◽  
Sandrine Da Cruz ◽  
Yves Mattenberger ◽  
Olivier Donzé ◽  
...  
Keyword(s):  
Cell Death ◽  
Morphological Changes ◽  
Mitochondrial Fission ◽  
Mitochondrial Network ◽  
Mitochondrial Fragmentation ◽  
Caspase Inhibition ◽  
Precise Role

ABSTRACT Apoptosis, induced by a number of death stimuli, is associated with a fragmentation of the mitochondrial network. These morphological changes in mitochondria have been shown to require proteins, such as Drp1 or hFis1, which are involved in regulating the fission of mitochondria. However, the precise role of mitochondrial fission during apoptosis remains elusive. Here we report that inhibiting the fission machinery in Bax/Bak-mediated apoptosis, by down-regulating of Drp1 or hFis1, prevents the fragmentation of the mitochondrial network and partially inhibits the release of cytochrome c from the mitochondria but fails to block the efflux of Smac/DIABLO. In addition, preventing mitochondrial fragmentation does not inhibit cell death induced by Bax/Bak-dependent death stimuli, in contrast to the effects of Bcl-xL or caspase inhibition. Therefore, the fission of mitochondria is a dispensable event in Bax/Bak-dependent apoptosis.

scholarly journals Regulation of Caspase-3 and Bcl-2 Expression in Dalton's Lymphoma Ascites Cells by Abrin

2009 ◽  
Vol 6 (2) ◽  
pp. 233-238 ◽  
Author(s):  
V. Ramnath ◽  
P. S. Rekha ◽  
G. Kuttan ◽  
R. Kuttan
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Morphological Changes ◽  
Suppressor Gene ◽  
Necrotic Cell ◽  
Induction Of Apoptosis ◽  
Dla Cells ◽  
Dalton’S Lymphoma ◽  
Dalton's Lymphoma

The role of abrin, a toxic lectin isolated from seeds ofAbrus precatoriusLinn in inducing apoptosis in murine Dalton's Lymphoma Ascites (DLA) cells was evaluated. Abrin when incubated at the concentration of 10 ng per million DLA cells could bring about cell death as typical morphological changes with apoptosis. However, necrotic cell death dominated when a higher dose of abrin was used. DNA samples, isolated from DLA cells treated with abrin showed fragmentation. Abrin brought about induction of apoptosis by stimulating the expression of pro-apoptotic Caspase-3, at the same time blocking the expression of Bcl-2, which is an anti apoptotic gene. However, the expression of tumor suppressor gene p53 has not been observed in control and abrin-treated DLA cells. Results suggested that abrin effectively induced apoptotic changes in the tumor cells that led to cellular death.

Cell death (apoptosis) during pancreatic involution after raw soya flour feeding in the rat

1986 ◽  
Vol 250 (1) ◽  
pp. G9-G14 ◽  
Author(s):  
P. S. Oates ◽  
R. G. Morgan ◽  
A. M. Light
Keyword(s):  
Cell Death ◽  
Acinar Cell ◽  
Morphological Changes ◽  
Acinar Cells ◽  
Normal Diet ◽  
Soya Flour ◽  
Apoptotic Bodies ◽  
Dna And Rna

Involution of the enlarged pancreas was studied in rats changed from a diet of raw soya flour (RSF) to a normal diet of cubes. After feeding RSF for 4 or 12 wk pancreatic weight, DNA, RNA, and protein were all significantly greater than in control animals fed cubes continuously. When these animals were changed to a cube diet, pancreatic DNA and RNA returned to control values within 48 h, while pancreatic weight and protein reverted to control values within 7 days of the change in diet. The morphological changes seen in the pancreas during involution indicate that cell death occurred by the process of apoptosis. Increased cell death during involution was seen as a rapid increase in the incidence of apoptotic bodies (AB) located in the cytoplasm of intact acinar cells and macrophages. These AB's contained condensed fragments of cytoplasm, nuclear, or a combination of these remnants, which were derived from the acinar cell. The increase in apoptosis after withdrawal of the RSF diet was probably in response to the withdrawal of the trophic influence, cholecystokinin.

Sign in / Sign up

Export Citation Format

Share Document