Author Correction: Quantitative spectrofluorometric assay detecting nuclear condensation and fragmentation in intact cells

AbstractAt present, nuclear condensation and fragmentation have been estimated also using Hoechst probes in fluorescence microscopy and flow cytometry. However, none of the methods used the Hoechst probes for quantitative spectrofluorometric assessment. Therefore, the aim of the present study was to develop a spectrofluorometric assay for detection of nuclear condensation and fragmentation in the intact cells. We used human hepatoma HepG2 and renal HK-2 cells cultured in 96-well plates treated with potent apoptotic inducers (i.e. cisplatin, staurosporine, camptothecin) for 6–48 h. Afterwards, the cells were incubated with Hoechst 33258 (2 µg/mL) and the increase of fluorescence after binding of the dye to DNA was measured. The developed spectrofluorometric assay was capable to detect nuclear changes caused by all tested apoptotic inducers. Then, we compared the outcomes of the spectrofluorometric assay with other methods detecting cell impairment and apoptosis (i.e. WST-1 and glutathione tests, TUNEL, DNA ladder, caspase activity, PARP-1 and JNKs expressions). We found that our developed spectrofluorometric assay provided results of the same sensitivity as the TUNEL assay but with the advantages of being fast processing, low-cost and a high throughput. Because nuclear condensation and fragmentation can be typical markers of cell death, especially in apoptosis, we suppose that the spectrofluorometric assay could become a routinely used method for characterizing cell death processes.

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Quantitative Spectrofluorometric Assay Detecting Nuclear Condensation and Fragmentation in Intact Cells

10.21203/rs.3.rs-208670/v1 ◽

2021 ◽

Author(s):

Pavlina Majtnerova ◽

Jan Capek ◽

Filip Petira ◽

Jiri Handl ◽

Tomáš Roušar

Keyword(s):

Cell Death ◽

Low Cost ◽

Caspase Activity ◽

Hoechst 33258 ◽

Dna Ladder ◽

Nuclear Condensation ◽

Intact Cells ◽

Fast Processing ◽

Nuclear Changes ◽

Cells Cultured

Abstract At present, nuclear condensation and fragmentation have been estimated also using Hoechst probes in fluorescence microscopy and flow cytometry. However, none of the methods has used the Hoechst probes for quantitative spectrofluorometric assessment. Therefore, the aim of present study was to develop a spectrofluorometric assay for detection of nuclear condensation and fragmentation in intact cells. We used HepG2 and HK‑2 cells cultured in 96-well plates which were treated with potent apoptotic inducers (i.e. cisplatin, staurosporine, camptothecin) for 6-48 h. Then, the cells were incubated with Hoechst 33258 (2 µg/mL) and the increase of fluorescence after binding of the dye to DNA was measured. The developed spectrofluorometric assay was capable to detect nuclear changes caused by all tested apoptotic inducers. Then, we compared the outcomes of the spectrofluorometric assay with other methods detecting apoptosis (i.e. TUNEL, DNA ladder, caspase activity). We found that the developed assay provides results of same sensitivity as TUNEL assay but the advantages of the spectrofluorometric assay are fast processing, low-cost and high throughput. Because nuclear condensation and fragmentation can be typical markers of cell death, especially in apoptosis, we suppose that the spectrofluorometric assay could become a routinely used method for characterizing cell death processes.

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Cell death of AKR-2B fibroblasts after serum removal: a process between apoptosis and necrosis

Journal of Cell Science ◽

10.1242/jcs.110.7.819 ◽

1997 ◽

Vol 110 (7) ◽

pp. 819-828 ◽

Cited By ~ 1

Author(s):

A. Simm ◽

G. Bertsch ◽

H. Frank ◽

U. Zimmermann ◽

J. Hoppe

Keyword(s):

Cell Death ◽

Propidium Iodide ◽

Structural Changes ◽

Energy State ◽

Energy Charge ◽

High Energy ◽

Serum Starvation ◽

Nuclear Condensation ◽

Mitochondrial Potential ◽

Intact Cells

AKR-2B cells disintegrate after serum removal. After a delay of approximately 90 minutes, cell death began and reached after six hours a plateau of 40–50% remaining living cells. We used time-lapse video microscopy to monitor dynamic structural changes and to measure the time span of individual cells to die. The first change was the rapid appearance of membrane blebs. Membrane vesicles were rapidly extruded and reintegrated by the cell. This highly dynamic process of an affected cell stopped after 80+/−20 minutes with its death. Conductivity measurements showed that at that time the membrane was electrically permeable. By using fluorescence double staining with propidium iodide and Hoechst 33258, we show that membrane leakage leading to disintegration is accompanied, and for some cells preceded, by nuclear condensation. The energy state of the intact cells was monitored by measuring the intracellular ATP content which remained high (6 mM) throughout the entire time of investigation. Mitochondrial potential was determined by rhodamine 123 fluorescence in parallel to the measurement of membrane permeability via uptake of propidium iodide and lead to the detection of a cell population that exhibits a high mitochondrial potential and an uptake of propidium iodide indicating a membrane disruption of cells which still have a high energy charge. It is shown by electron microscopy that mitochondria were swollen and damaged in parallel to nuclear condensation. There was no DNA fragmentation as shown by two independent methods. Addition of the ICE-like protease inhibitor tyr-val-ala-asp-chloromethylketone immediately after serum starvation lead to an almost complete survival of the cells up to 6 hours. A pronounced protection was still observed after 24 hours, suggesting an involvement of this type of protease in the onset of cell death after serum removal. Apparently, serum withdrawal activates a succession of initial events that are similar to those defined as ‘apoptosis’, i.e. nuclear condensation and membrane blebbing. These steps are, however, accompanied or rapidly followed by cell lysis and disruption of mitochondria, both of which are characteristic of necrosis.

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Cell death induced by granzyme C

Blood ◽

10.1182/blood-2002-08-2485 ◽

2003 ◽

Vol 101 (8) ◽

pp. 3093-3101 ◽

Cited By ~ 80

Author(s):

Hillary Johnson ◽

Luca Scorrano ◽

Stanley J. Korsmeyer ◽

Timothy J. Ley

Keyword(s):

Cell Death ◽

Granzyme B ◽

The Other ◽

Cytotoxic Lymphocytes ◽

Nuclear Condensation ◽

Intact Cells ◽

Isolated Mitochondria ◽

Molar Basis ◽

Dna Nicking ◽

Kinetics Of

Abstract Although the functions of granzymes A and B have been defined, the functions of the other highly expressed granzymes (Gzms) of murine cytotoxic lymphocytes (C, D, and F) have not yet been evaluated. In this report, we describe the ability of murine GzmC (which is most closely related to human granzyme H) to cause cell death. The induction of death requires its protease activity and is characterized by the rapid externalization of phosphatidylserine, nuclear condensation and collapse, and single-stranded DNA nicking. The kinetics of these events are similar to those caused by granzyme B, and its potency (defined on a molar basis) is also equivalent. The induction of death did not involve the activation of caspases, the cleavage of BID, or the activation of the CAD nuclease. However, granzyme C did cause rapid mitochondrial swelling and depolarization in intact cells or in isolated mitochondria, and this mitochondrial damage was not prevented by cyclosporin A pretreatment. These results suggest that granzyme C rapidly induces target cell death by attacking nuclear and mitochondrial targets and that these targets are distinct from those used by granzyme B to cause classical apoptosis.

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Oncornavirus assembly at the cell surface revealed in replicas of freeze-dried cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082637 ◽

1978 ◽

Vol 36 (2) ◽

pp. 354-355

Author(s):

Anthony Demsey ◽

Christopher W. Stackpole

Keyword(s):

Cell Surface ◽

Surface Membrane ◽

Viral Origin ◽

Intact Cells ◽

Structural Formation ◽

Virus Core ◽

Freeze Dried ◽

Cacodylate Buffer ◽

Surface Replica ◽

Leukemia Viruses

The murine leukemia viruses are type-C oncornaviruses, and their release from the host cell involves a “budding” process in which the newly-forming, RNA-containing virus core becomes enveloped by modified cell surface membrane. Previous studies revealed that the released virions possess a dense array of 10 nm globular projections (“knobs”) on this envelope surface, and that these knobs contain a 70, 000 MW glycoprotein (gp70) of viral origin. Taking advantage of this distinctive structural formation, we have developed a procedure for freeze-drying and replication of intact cells which reveals surface detail superior to other surface replica techniques, and sufficient to detect even early stages of virus budding by localized aggregation of these knobs on the cell surface.Briefly, cells growing in monolayer are seeded onto round glass coverslips 10-12 mm in diameter. After a period of growth, cells are fixed in situ for one hour, usually with 1% OsO4 in 0. 1 M cacodylate buffer, and rinsed in distilled water.

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Detection and mapping of interactions between chromatin and the nuclear envelope in drosophila embryos

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140191 ◽

1995 ◽

Vol 53 ◽

pp. 764-765

Author(s):

W.F. Marshall ◽

A.F. Dernburg ◽

B. Harmon ◽

J.W. Sedat

Keyword(s):

Nuclear Envelope ◽

Chromatin Condensation ◽

Three Dimensional ◽

Physiological Role ◽

Nuclear Surface ◽

Intact Cells ◽

Molecular Determinants ◽

Surface Harmonic ◽

Drosophila Embryos

Interactions between chromatin and nuclear envelope (NE) have been implicated in chromatin condensation, gene regulation, nuclear reassembly, and organization of chromosomes within the nucleus. To further investigate the physiological role played by such interactions, it will be necessary to determine which loci specifically interact with the nuclear envelope. This will not only facilitate identification of the molecular determinants of this interaction, but will also allow manipulation of the pattern of chromatin-NE interactions to probe possible functions. We have developed a microscopic approach to detect and map chromatin-NE interactions inside intact cells.Fluorescence in situ hybridization (FISH) is used to localize specific chromosomal regions within the nucleus of Drosophila embryos and anti-lamin immunofluorescence is used to detect the nuclear envelope. Widefield deconvolution microscopy is then used to obtain a three-dimensional image of the sample (Fig. 1). The nuclear surface is represented by a surface-harmonic expansion (Fig 2). A statistical test for association of the FISH spot with the surface is then performed.

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The Uptake of Adenine by Isolated Human Platelet Membranes

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647713 ◽

1974 ◽

Vol 32 (02/03) ◽

pp. 457-464

Author(s):

Paul C. French ◽

Jan J. Sixma ◽

Holm Holmsen

Keyword(s):

Human Platelet ◽

Facilitated Diffusion ◽

Adenine Phosphoribosyltransferase ◽

Ph Optimum ◽

Intact Cells ◽

Platelet Membranes ◽

Group Translocation ◽

Triton X

SummaryAdenine uptake into isolated platelet membranes had about the same Km (151 ± 21 • 9 nM) as uptake into intact cells (159 ± 21 nM) and was also competitively inhibited by papaverine and hypoxanthine. No uptake occurred at 0° and accumulated adenine was converted to AMP. AMP was not firmly bound to protein as judged by chromatography of triton X-100 solubilized membranes on Sephadex G25. The pH optimum for adenine uptake was at pH 5-5. Exogenous 5-phosphoribosyl-l-pyrophos- phate strongly stimulated uptake. These data may be explained by uptake of adenine by facilitated diffusion followed by conversion to AMP by adenine phosphoribosyltransferase but group translocation cannot be entirely excluded.

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