Cell Apoptotic Bodies Research Articles

Toxoplasma gondii-infected human myeloid dendritic cells induce T-lymphocyte dysfunction and contact-dependent apoptosis.

Dendritic cells ignite adaptive immunity by priming naïve T lymphocytes. Human monocyte-derived dendritic cells (MDDCs) infected with Toxoplasma gondii induce T-lymphocyte gamma interferon production and may thus activate T. gondii-specific immunity. However, we now demonstrate that T. gondii-infected MDDCs are poor at activating T lymphocytes and are unable to induce specific cytotoxic T lymphocytes. On the other hand, MDDCs acquiring nonviable T. gondii antigens directly, or indirectly through captured apoptotic or necrotic cell bodies, induce potent T-lymphocyte activation. T lymphocytes exposed to infected MDDCs are significantly impaired in upregulation of CD69 and CD28, are refractory to activation, and die through contact-dependent apoptosis mediated by an as-yet-unidentified mechanism not requiring Fas, tumor necrosis factor-related apoptosis-inducing ligand, leukocyte function antigen 1, intercellular adhesion molecule 1, tumor necrosis factor alpha, interleukin 10, alpha interferon, gamma interferon, prostaglandins, or reactive nitrogen intermediates. Bystander T lymphocytes that were neither infected nor apoptotic were refractory to activation, suggesting global dysfunction. Immunosuppression and T-lymphocyte unresponsiveness and apoptosis are typical of acute T. gondii infection. Our data suggest that infected dendritic cells contribute to these processes. On the other hand, host cells infected with T. gondii are resistant to multiple inducers of apoptosis. Thus, regulation of host cell and bystander cell apoptosis by viable T. gondii may be significant components of a strategy to evade immunity and enhance intracellular parasite survival.

Dynamics of apoptosis in the ovarian follicle cells during the late stages of Drosophila oogenesis.

In the present study, we demonstrate the apoptotic events of the ovarian follicle cells during the late stages of oogenesis in Drosophila melanogaster. Follicle cell morphology appears normal from stage 10 up to stage 14, exhibiting a euchromatic nucleus and a well-organized cytoplasm. First signs of apoptosis appear at the anterior pole of the egg chamber at stage 14A. They are characterized by loss of microvilli at the apical cell membrane, alterations in nuclear morphology, such as chromatin condensation and convolution of the nuclear membrane, and also by condensation and vacuolization of the cytoplasm. During the following stage 14B, the follicle cell nuclei contain fragmented DNA as is demonstrated by acridine orange staining and TUNEL (TdT-mediated dUTP nick end-labeling) assay. Finally, the apoptotic follicle cells seem to detach from the eggshell when the mature egg chamber exits the ovariole. The detached follicle cells exhibit condensed nuclear chromatin, a disorganized cytoplasm with crowded organelles and are surrounded by epithelial cells. The above results seem to be associated with the abundant phagocytosis that we observed at the entry of the lateral oviducts, where the epithelial cells contain apoptotic cell bodies. Additionally, we tested the effect of etoposide treatment in the follicular epithelium and found that it induces apoptosis in a stage- and site-specific manner. These observations suggest a possible method of absorption of the apoptotic follicle cells that prevents the blockage of the ovarioles and helps the regular production of mature eggs.

金時草（スイゼンジナ）色素抽出物のがん細胞アポトーシス誘導効果

(Gynura bicolor DC.) is a traditional vegetable in Ishikawa prefecture. Kinjiso hot water extract containing the natural colored compounds anthocyanins was fractionated into the adsorbed-and the non-adsorbed fractions by SepPakC18 column chromatography. Kinjiso hot water extract and the SepPakC18 column adsorbed fraction showed the inhibitory effect of the HL60 human leukemia cell growth and the scavenging activity towards DPPH radical. Both effects of the SepPakC18 column adsorbed fraction were higher than those of the hot water extract. The anthocyans peralgonidin, delphinidin, malvidin and oenin (malvidin 3-glucoside) inhibited the HL60 cell growth. The Kinjiso SepPakC18 column adsorbed fraction and the anthocyanidins peralgonidin, delphinidin and malvidin induced the apoptotic cell bodies and oligonucleosomal DNA fragmentation in HL60 The results indicated that the Kinjiso SepPakC18 column adsorbed fraction and the anthocyanidins induced apoptosis in HL60 Kinjiso SepPakC18 column adsorbed fraction was further fractionated by Sephadex LH20 column chromatography. Both of the fractions that containing large and small amount of anthocyanins inhibited cell growth and induced apoptosis in HL60 The result suggests that Kinjiso SepPakC18 column adsorbed fraction contain not only anthocyanins but also other components induced the apoptosis in HL60 The SepPakC18 column adsorbed fraction is possibly used as the coloring additive that shows the radical scavenging activity and apoptosis inducing effect in cancer cells.

Variation in the kinetics of caspase-3 activation, Bcl-2 phosphorylation and apoptotic morphology in unselected human ovarian cancer cell lines as a response to docetaxel

Variation in the kinetics of caspase-3 activation, Bcl-2 phosphorylation and apoptotic morphology in unselected human ovarian cancer cell lines as a response to docetaxel

Apoptosis and expression of stress protein (ORP150, HO1) during development of ischaemic osteonecrosis in the rat

Using in situ hybridisation and the terminal deoxynucleotidyl transferase-mediated biotin-dUTP nick end-labelling (TUNEL) reaction in rats with osteonecrosis of the femoral head we have studied the effect of ischaemia on the gene expression of the stress proteins oxygen-regulated protein 150 (ORP150) and haemoxygenase 1 (HO1) and the death mechanism of the cells involved in osteonecrosis. Both ORP150 and HO1 have been reported to have important roles in the successful adaptation to oxygen deprivation. ORP150 and HO1 mRNA expression was induced by ischaemia in osteoblasts and osteocytes. In proliferative chondrocytes, these signals were detected constitutively. During the development of ischaemic osteonecrosis, the mechanism of cell death was apoptosis as indicated by DNA fragmentation and the presence of apoptotic bodies in osteocytes, chondrocytes and bone-marrow cells. After the initial ischaemic event, expression of ORP150 and HO1 mRNA, the TUNEL-positive reaction and empty lacunae were found sequentially. These findings were exclusive and may be considered to be markers for each stage in the development of osteonecrosis.

Molecular undertaker identified

Molecular undertaker identified

Rho-activating Escherichia coli cytotoxic necrotizing factor 1: macropinocytosis of apoptotic bodies in human epithelial cells

Rho-activating Escherichia coli cytotoxic necrotizing factor 1: macropinocytosis of apoptotic bodies in human epithelial cells

Transmission Electron and Immunoelectron Microscopic Studies on Microcystin-LR-Induced Hepatic Injuries in Mice.

A cyanobacterial toxin, microcystin-LR (MCLR), is a potent inhibitor of protein phosphatase that disrupts cytoskeleton network in hepatocytes. Conventional transmission electron and immunoelectron microscopic studies were conducted in the liver from mice that received a single dose of MCLR and were sacrificed at 24 hours after dosing. The two types of death of hepatocytes, necrosis and apoptosis, were observed concomitantly, and the hepatic injuries, therefore, could be classified as a class of mixed apoptotic and oncotic necrosis according to the recommended criterion by the Society of Toxicologic Pathologists. Apoptotic hepatocytes were characterized by ballooning with numerous intracytoplasmic vacuoles in addition to the common features of apoptotic cells referred in the literatures. In non-parenchymal cells, significant changes indicating microcirculatory alterations and inflammatory reactions included activation of endothelial cells and Kupffer cells, widening of sinusoidal endothelial fenestrae, apoptosis of endothelial cells, accumulation of platelets and polymorphonuclear neutrophils, and fibrin deposition. Pre-embedding immunoelectron microscopy with biotinylated anti-microcystin antibody demonstrated that MCLR was heterogeneously apparent in the cytoplasm of hepatocytes and strong immunoreactivity was evident in apoptotic cell/bodies. In non-parenchymal cells, there were no positive reactions except for phagocytic apoptotic bodies in Kupffer cells. These results suggest that liver damages induced by MCLR are ascribed to primary cytotoxic effects of the toxin localized in hepatocytes and secondary microcirculatory alterations and inflammatory reactions involved non-parenchymal cells.

Dendritic cells: at the clinical crossroads.

Dendritic cells: at the clinical crossroads.

Protective effects of soyasapogenol A on liver injury mediated by immune response in a concanavalin A-induced hepatitis model

Protective effects of soyasapogenol A on liver injury mediated by immune response in a concanavalin A-induced hepatitis model

Apoptosis in the pattern formation of the ventricular wall during mouse heart organogenesis.

Apoptosis is an important mechanism in organogenesis, but its role in heart development has been poorly characterized. We have here studied apoptosis in the developing ventricular wall of mouse embryonic heart. Developing mice hearts on days 11 to 16 of gestation were studied using in situ end-labeling of degraded DNA (TUNEL), immunocytochemistry of regulatory genes Bcl-2 and Bax, and light and electron microscopy. TUNEL end-labeled apoptotic cells were found in the ventricular wall on days 11 to 16 of gestation. The proportions of apoptotic cells of all cells in the ventricular wall differed between the trabecular and compact regions (P = 0.003) and between the days of gestation (P = 0.0001), the calculated apoptotic index was greater in the compact region at all ages except day 14. Ultrastructural analysis showed typical apoptotic shrinkage, chromatin degradation, and apoptotic bodies in several myoblastic and myocardial endothelial cells which were also positive by DNA end-labeling. Immunocytochemical reaction for the apoptosis checkpoint proteins in the ventricular wall showed clearly more Bcl-2 positive cells than Bax positive cells. The numerical densities of all cells in the compact and trabecular regions remained always higher in the compact region (P = 0.04) despite the fact that apoptosis was present in both areas at the same time. In conclusion, apoptosis takes place in the developing myocardial muscle as well as the myocardial endothelium during ventricular morphogenesis on days 11 through 16 and decreases clearly on day 16. We suggest that apoptosis and its regulatory factors are closely involved in the morphogenesis of the ventricular wall of the mammalian heart.

Oxyhemoglobin-induced apoptosis in cultured endothelial cells.

Oxyhemoglobin (OxyHb) is one of the most important spasmogens for cerebral vasospasm that follows aneurysmal subarachnoid hemorrhage. The cytotoxic effect of OxyHb has been documented in endothelial and smooth-muscle cells; however, the pattern of cell death--necrosis or apoptosis--as the final stage of cell damage has not been demonstrated. This study was undertaken to determine if OxyHb induces apoptotic changes in cultured bovine aortic endothelial cells. Confluent bovine aortic endothelial cells were treated with OxyHb in a concentration- and time-dependent manner. Cell density was assayed by counting the number of cells that attached to culture dishes after exposure to OxyHb. To identify apoptotic changes, the investigators used three specific methods: DNA fragmentation (electrophoreses), the apoptotic body (transmission electron microscopy), and cleavage of poly (adenosine diphosphate ribose) polymerase (PARP [Western blotting]). Oxyhemoglobin decreased cell density in a concentration- and time-dependent manner. Analysis of DNA showed a pattern of internucleosomal cleavage characteristic of apoptosis (DNA ladder). Transmission electron microscopy demonstrated condensation of nuclei and apoptotic bodies in OxyHb-treated endothelial cells. Western blotting with the PARP antibody revealed that the 116-kD PARP was cleaved to the 85-kD apoptosis-related fragment. These results for the first time demonstrated that the OxyHb induces apoptosis in cultured endothelial cells.

Apoptosis Induced by a Marine Birnavirus in Established Cell Lines from Fish.

This study was undertaken to determine whether marine birnavirus (MABV) can induce apoptosis in vitro in cell lines established from four different fish species. MABV Y-6 strain was inoculated onto chinook salmon embryo (CHSE-214), red sea bream kidney (RSBK-2), fathead minnow caudal peduncle (FHM) and epithelioma papulosum cyprini (EPC) cell lines at a multiplicity of infection (m.o.i.) of 0.1. At 0, 12, 24, 36, 48, 72, and 96 h post-infection, the cells were harvested and used for DNA fragmentation analysis, apoptotic cell counts and determination of virus titer by plaque assay. MABV infection appeared to induce the typical features of apoptosis such as nuclear and cytoplasmic condensation, DNA fragmentation and formation of apoptotic bodies in CHSE-214 and RSBK-2 cells, but not in FHM and EPC cells. The concentration of free virus increased immediately after infection, whereas the apoptotic cell ratio and cell-associated virus titer scarecely increased until 24 h. Apoptotsis increased after 36 h when monitored by counting of apoptotic cells and analysis of DNA. The results suggest that MABV replicating to high concentrations during an early stage of infection induces apoptosis in later stages.

Homozygous C1q deficiency causes glomerulonephritis associated with multiple apoptotic bodies.

The complement system plays a paradoxical role in the development and expression of autoimmunity in humans. The activation of complement in systemic lupus erythematosus (SLE) contributes to tissue injury. In contrast, inherited deficiency of classical pathway components, particularly C1q (ref. 1), is powerfully associated with the development of SLE. This leads to the hypothesis that a physiological action of the early part of the classical pathway protects against the development of SLE (ref. 2) and implies that C1q may play a key role in this respect. C1q-deficient (C1qa-/-) mice were generated by gene targeting and monitored for eight months. C1qa-/- mice had increased mortality and higher titres of autoantibodies, compared with strain-matched controls. Of the C1qa-/- mice, 25% had glomerulonephritis with immune deposits and multiple apoptotic cell bodies. Among mice without glomerulonephritis, there were significantly greater numbers of glomerular apoptotic bodies in C1q-deficient mice compared with controls. The phenotype associated with C1q deficiency was modified by background genes. These findings are compatible with the hypothesis that C1q deficiency causes autoimmunity by impairment of the clearance of apoptotic cells.

Effects of luteal phase administration of mifepristone (RU486) and prostaglandin analogue or inhibitor on endometrium in the rhesus monkey.

Early luteal phase administration of a potent anti-progestin like mifepristone (RU486) inhibits blastocyst implantation and the establishment of pregnancy without marked changes in menstrual cyclicity and ovarian steroid hormone profiles; however, the underlying mechanism is not very clear. In the present study, a hypothesis that prostaglandins (PG) are involved in the anti-gestatory action of luteal phase mifepristone was tested. Endometrial changes in rhesus monkeys were examined following luteal phase administration of mifepristone, a prostaglandin synthesis inhibitor (diclofenac) and a prostaglandin analogue (misoprostol) either alone or in combination. Twenty-five monkeys were randomly assigned to six groups: group 1 (n = 4), normal control group; group 2 (n = 4), mifepristone (2 mg, daily, s.c.) treated group; group 3 (n = 4), diclofenac (25 mg, daily, i.m.) treated group; group 4 (n = 4), misoprostol (100 microg, daily, oral) treated group; group 5 (n = 5), mifepristone and diclofenac (same dosages as for groups 2 and 3) treated group; group 6 (n = 4), mifepristone and misoprostol (same dosages as for groups 2 and 4) treated group. All treatments were given to monkeys on days 16-18 of mated cycles and endometrial tissue samples were collected on day 20. With diclofenac alone (group 3), marginal changes were observed in glandular, stromal and vascular compartments, and there were few apoptotic bodies in gland cells; partial inhibition and delay in implantation was earlier reported. Significantly higher oestrogen receptor expression in glandular epithelial cells as compared with all other treatment groups was found after treatment with misoprostol alone (group 4) and was associated with normal fecundity. The anti-nidatory action of luteal phase antiprogestin treatment alone or in combination with diclofenac or misoprostol was associated with altered endometrial histometric features characterized by glandular apoptosis, regression in secretory functions, decreased oedema, extravasation and a higher degree of stromal leukocytic infiltration. In these three groups (groups 2, 5 and 6) receptors for oestrogen and progesterone receptors were significantly higher in stromal cells, and lower in vascular cells, while glandular cells showed significantly higher progesterone receptors compared with the control group. The anti-nidatory activity of mifepristone and associated endometrial changes could not be accentuated or attenuated with co-administration of PGE or diclofenac, nor could these be mimicked by these agents alone.

Kainate-induced apoptosis correlates with c-Jun activation in cultured cerebellar granule cells.

We have investigated the involvement of c-Jun in cell death induced by exposure of primary cultures of murine cerebellar granule cells to the glutamate receptor agonist kainate (KA) and evaluated its possible use as a marker for apoptosis. Using cerebellar granule cell neurones from postnatal day 7 mice, we found that 1 hr exposure to KA (1-1000 microM) induced a concentration-dependent neuronal cell death with characteristic apoptotic morphology, including cell shrinkage, neurite blebbing and DNA fragmentation. In addition KA-induced a concentration-dependent expression of c-Jun mRNA and protein as determined by in situ hybridization and immunocytochemistry respectively. DNA fragmentation was detected using terminal transferase-mediated nick-end (TUNEL) labelling and agarose gel electrophoresis. KA-induced cell death was significantly attenuated by the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 50 microM), which shifted the concentration-response curve significantly rightward. The number of apoptotic cell bodies, determined by TUNEL, was also reduced by CNQX (50 microM), with only 15-20% of neurones staining positive after exposure to 1mM KA. In addition, the number of positively stained cells for c-Jun protein and mRNA was substantially reduced by CNQX (50 microM) as determined by random and representative cell counts. These results show for the first time that KA induced apoptotic neuronal death in cultured murine cerebellar granule cells involves the induction of c-Jun mRNA and protein, suggesting the involvement of this immediate early gene in excitotoxic receptor-mediated apoptosis and its potential use as a marker for apoptotic cell death.

Apoptosis is induced by choline deficiency in fetal brain and in PC12 cells

Apoptosis is induced by choline deficiency in fetal brain and in PC12 cells

Developed and resolving lesions in porcine proliferative enteropathy: Possible pathogenetic mechanisms

Developed and resolving lesions in porcine proliferative enteropathy: Possible pathogenetic mechanisms

Fumonisins and Alternaria alternata lycopersici toxins: sphinganine analog mycotoxins induce apoptosis in monkey kidney cells.

Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell homeostasis were investigated in African green monkey kidney cells (CV-1) by assessing the appearance of apoptosis, cell cycle regulation, and putative components of signal transduction pathways involved in apoptosis. Structurally, these mycotoxins resemble the sphingoid bases, sphingosine and sphinganine, that are reported to play critical roles in cell communication and signal transduction. The addition of fumonisin B1 or AAL toxin, TA, to CV-1 cells induced the stereotypical hallmarks of apoptosis, including the formation of DNA ladders, compaction of nuclear DNA, and the subsequent appearance of apoptotic bodies. Neither mycotoxin induced cell death, DNA ladders, or apoptotic bodies in CV-1 cells expressing simian virus 40 large T antigen (COS-7) at toxin concentrations that readily killed CV-1 cells. Fumonisin B1 induced cell cycle arrest in the G1 phase in CV-1 cells but not in COS-7 cells. AAL toxin TA did not arrest cell cycle progression in either cell line. The induction of apoptosis combined with the widespread presence of these compounds in food crops and animal feed identifies a previously unrecognized health risk to humans and livestock. These molecules also represent a new class of natural toxicants that can be used as model compounds to further characterize the molecular and biochemical pathways leading to apoptosis.

Inhibition of apoptosis by antioxidants in the human HL-60 leukemia cell line

Inhibition of apoptosis by antioxidants in the human HL-60 leukemia cell line