scholarly journals Heat shock-induced apoptosis in germ line cells of Triatoma infestans Klug

2000 ◽  
Vol 23 (2) ◽  
pp. 301-304 ◽  
Author(s):  
Maria Luiza S. Mello ◽  
Sílvya S. Maria ◽  
Maria Cristina H. Tavares
Keyword(s):  
Cell Death ◽  
Heat Shock ◽  
Dna Fragmentation ◽  
Cellular Differentiation ◽  
Germ Line ◽  
Triatoma Infestans ◽  
Sperm Cells ◽  
Immunocytochemical Assay ◽  
Induced Apoptosis ◽  
Shock Exposure

The survival of Triatoma infestans and of somatic cells from this species is affected by heat shock. In this study, we examined the cell death responses of male germ line cells from 5th instar nymphs 7 and 30 days after heat shock exposure (40ºC, 1 h). The preparations were stained by the Feulgen reaction and the TUNEL immunocytochemical assay. Apoptosis was elicited by heat shock, with positive TUNEL responses in spermatogonial chromatin and chromosomes, spermatids and sperm cells. Spermatogonia were most affected seven days after the shock whereas some spermatids and sperm cells exhibited DNA fragmentation only thirty days after heat shock. The rate of cell death varied among the cells. In some cases, cellular differentiation was unaffected by heat shock, with DNA fragmentation occurring towards the end of spermatogenesis.

scholarly journals Activation of the heat shock response in a primary cellular model of motoneuron neurodegeneration-evidence for neuroprotective and neurotoxic effects

2009 ◽  
Vol 14 (2) ◽  
Author(s):  
Bernadett Kalmar ◽  
Linda Greensmith
Keyword(s):  
Cell Death ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Apoptotic Cell ◽  
Experimental Conditions ◽  
Pharmacological Agents ◽  
Shock Response ◽  
Induced Apoptosis ◽  
Shock Proteins ◽  
The Relationship

AbstractPharmacological up-regulation of heat shock proteins (hsps) rescues motoneurons from cell death in a mouse model of amyotrophic lateral sclerosis. However, the relationship between increased hsp expression and neuronal survival is not straightforward. Here we examined the effects of two pharmacological agents that induce the heat shock response via activation of HSF-1, on stressed primary motoneurons in culture. Although both arimoclomol and celastrol induced the expression of Hsp70, their effects on primary motoneurons in culture were significantly different. Whereas arimoclomol had survival-promoting effects, rescuing motoneurons from staurosporin and H2O2 induced apoptosis, celastrol not only failed to protect stressed motoneurons from apoptosis under same experimental conditions, but was neurotoxic and induced neuronal death. Immunostaining of celastrol-treated cultures for hsp70 and activated caspase-3 revealed that celastrol treatment activates both the heat shock response and the apoptotic cell death cascade. These results indicate that not all agents that activate the heat shock response will necessarily be neuroprotective.

Redistribution of phosphatidylethanolamine and phosphatidylserine precedes reperfusion-induced apoptosis

1998 ◽  
Vol 274 (1) ◽  
pp. H242-H248 ◽  
Author(s):  
Nilanjana Maulik ◽  
Valerian E. Kagan ◽  
Vladimir A. Tyurin ◽  
Dipak K. Das
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Genomic Dna ◽  
High Performance ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Apoptotic Cell Death ◽  
Dna Laddering ◽  
Outer Leaflet ◽  
Induced Apoptosis

Although cardiomyocyte death and infarction associated with ischemia-reperfusion are traditionally believed to be induced via necrosis, recent studies implicated apoptotic cell death in ischemic reperfused tissue. To examine whether myocardial ischemic reperfusion injury is mediated by apoptotic cell death, isolated perfused rat hearts were subjected to 15 and 30 min of ischemia as well as 15 min of ischemia followed by 30, 90, or 120 min of reperfusion. At the end of each experiment, hearts were processed for the evaluation of apoptosis and DNA laddering. Apoptosis was studied by visualizing the apoptotic cardiomyocytes by direct fluorescence detection of digoxigenin-labeled genomic DNA using APOPTAG in situ apoptosis detection kit. DNA laddering was evaluated by subjecting the DNA obtained from cardiomyocytes to 1.8% agarose gel electrophoresis and photographed under ultraviolet illumination. In addition, high-performance thin-layer chromatography (HPTLC) of aminophospholipids labeled with 2,4,6-trinitrobenzenesulfonate was performed to evaluate phospholipid topography in cardiomyocytes. The results of our study revealed apoptotic cells only in the 90- and 120-min reperfused hearts as demonstrated by the intense fluorescence of the immunostained digoxigenin-labeled genomic DNA when observed under fluorescence microscope. None of the ischemic hearts showed any evidence of apoptosis. These results corroborated with the findings of DNA fragmentation that showed increased ladders of DNA bands in the 120-min reperfused hearts, representing integer multiples of the internucleosomal DNA length (∼180 bp). Two-dimensional HPTLC of the phospholipids obtained from the cardiomyocytes and transbilayer organization of the phosphatidylethanolamine (PE) and phosphatidylserine (PS) in the myocytes indicated translocation of both PE and PS from the inner leaflet to the outer leaflet of the membrane as early as after 20 min of ischemia. These results demonstrate that the redistribution of PS and PE precedes the apototic cell death and DNA fragmentation associated with the reperfusion of ischemic myocardium, suggesting that ischemia may trigger the signal for apoptosis although it becomes evident during reperfusion.

Oestrogens as apoptosis regulators in mammalian testis: angels or devils?

2015 ◽  
Vol 17 ◽  
Author(s):  
Sara Correia ◽  
Henrique J. Cardoso ◽  
José E. Cavaco ◽  
Sílvia Socorro
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Cell Survival ◽  
Cell Fate ◽  
Germ Line ◽  
Clinical Findings ◽  
Molecular Events ◽  
Mammalian Testis ◽  
Induced Apoptosis ◽  
Available Information

In the mammalian testis, spermatogenesis is a highly coordinated process of germ cell development, which ends with the release of ‘mature’ spermatozoa. The fine regulation of spermatogenesis is strictly dependent on sex steroid hormones, which orchestrate the cellular and molecular events underlying normal development of germ cells. Sex steroids actions also rely on the control of germ cell survival, and the programmed cell death by apoptosis has been indicated as a critical process in regulating the size and quality of the germ line. Recently, oestrogens have emerged as important regulators of germ cell fate. However, the beneficial or detrimental effects of oestrogens in spermatogenesis are controversial, with independent reports arguing for their role as cell survival factors or as apoptosis-inducers. The dual behaviour of oestrogens, shifting from ‘angels to devils’ is supported by the clinical findings of increased oestrogens levels in serum and intratesticular milieu of idiopathic infertile men. This review aims to discuss the available information concerning the role of oestrogens in the control of germ cell death and summarises the signalling mechanisms driven oestrogen-induced apoptosis. The present data represent a valuable basis for the clinical management of hyperoestrogenism-related infertility and provide a rationale for the use of oestrogen-target therapies in male infertility.

scholarly journals Fas Induces Cytoplasmic Apoptotic Responses and Activation of the MKK7-JNK/SAPK and MKK6-p38 Pathways Independent of CPP32-like Proteases

1997 ◽  
Vol 139 (4) ◽  
pp. 1005-1015 ◽  
Author(s):  
Fumiko Toyoshima ◽  
Tetsuo Moriguchi ◽  
Eisuke Nishida
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Morphological Changes ◽  
Chromatin Condensation ◽  
Cysteine Proteases ◽  
Cellular Responses ◽  
Jurkat Cells ◽  
Mitogen Activated Protein Kinase ◽  
Fas Signaling ◽  
Induced Apoptosis

IL-1β converting enzyme (ICE) family cysteine proteases are subdivided into three groups; ICE-, CPP32-, and Ich-1–like proteases. In Fas-induced apoptosis, activation of ICE-like proteases is followed by activation of CPP32-like proteases which is thought to be essential for execution of the cell death. It was recently reported that two subfamily members of the mitogen-activated protein kinase superfamily, JNK/SAPK and p38, are activated during Fas-induced apoptosis. Here, we have shown that MKK7, but not SEK1/ MKK4, is activated by Fas as an activator for JNK/ SAPK and that MKK6 is a major activator for p38 in Fas signaling. Then, to dissect various cellular responses induced by Fas, we used several peptide inhibitors for ICE family proteases in Fas-treated Jurkat cells and KB cells. While Z-VAD-FK which inhibited almost all the Fas-induced cellular responses blocked the activation of JNK/SAPK and p38, Ac-DEVD-CHO and Z-DEVD-FK, specific inhibitors for CPP32-like proteases, which inhibited the Fas-induced chromatin condensation and DNA fragmentation did not block the activation of JNK/SAPK and p38. Interestingly, these DEVD-type inhibitors did not block the Fas-induced morphological changes (cell shrinkage and surface blebbing), induction of Apo2.7 antigen, or the cell death (as assessed by the dye exclusion ability). These results suggest that the Fas-induced activation of the JNK/SAPK and p38 signaling pathways does not require CPP32-like proteases and that CPP32-like proteases, although essential for apoptotic nuclear events (such as chromatin condensation and DNA fragmentation), are not required for other apoptotic events in the cytoplasm or the cell death itself. Thus, the Fas signaling pathway diverges into multiple, separate processes, each of which may be responsible for part of the apoptotic cellular responses.

Inhibitors of Heat Shock Protein 72 Induction Enhance Apoptosis Induced by Hsp90 Inhibitors

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2625-2625
Author(s):  
Emma Davenport ◽  
Athanasia Zeisig ◽  
Lauren Wiseglass ◽  
Hannah E. Moore ◽  
Sarah L. Hockley ◽  
...  
Keyword(s):  
Cell Death ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Er Stress ◽  
Proteasome Inhibitors ◽  
Hsp90 Inhibitors ◽  
Drug Induced ◽  
Myeloma Cells ◽  
Induced Apoptosis ◽  
Hsp70 Induction

Abstract Exposure of myeloma cells to Hsp90 inhibitors (eg 17-AAG) or proteasome inhibitors (eg Bortezomib) results in a time-dependent induction of heat shock protein 72 (Hsp72), protecting cells from drug-induced apoptosis. Hsp72 is a member of the heat shock protein 70 (Hsp70) family and enables cells to cope with harmful aggregations of proteins during and after stress, protecting cells from apoptosis in addition to acting as a chaperone for proteins such as immunoglobulin. We show that inhibition of Hsp72 upregulation induced by these anti-myeloma drugs, by either inhibitors of Hsp70 induction or siRNA, increases susceptibility of myeloma cells to drug-induced apoptosis. This provides a rationale for using such inhibitors in combination with anti-myeloma drugs. A number of commercially available inhibitors of Hsp70 induction, including KNK437 and triptolide, were used to inhibit stress-induced upregulation of Hsp72. Combining Hsp90 inhibitors (Hsp90i) with these compounds increased cell death to 73% from 33% when Hsp90i were used alone. Cell cycle analysis indicated that combining these compounds with Hsp90 inhibitors overcame the G2 growth arrest induced by Hsp90 inhibitors and increased the proportion of cells in sub G1, indicative of apoptosis. Analysis of their anti-proliferative effects demonstrated that, in H929 cells, Hsp90 inhibitor/triptolide combinations had additive effects whilst in U266 cells their effects were synergistic. To determine the underlying mechanisms responsible for the effects of the combination, key proteins involved in endoplasmic reticulum (ER) stress, Unfolded Protein Response and caspase-dependent and independent signalling pathways were analysed. We show that ER stress signalling through IRE1 and PERK pathways, measured by cleavage of XBP1 and induction of CHOP, were initiated earlier and sustained longer, when cells were treated with the combination. Similarly, analysis of caspase-dependent and independent signalling demonstrated that the combination induced early cleavage of caspases 9, 8 and 3 which was sustained. Nuclear translocation of AIF, the caspase-independent cell death signal, was strongly induced suggestive of strong activation of this pathway. We demonstrate that death induced by triptolide or its combination with 17-AAG is p53-independent using of a panel of myeloma cell lines. To confirm our findings, we used lentiviral siRNA constructs targeting the inducible forms of Hsp70 and then analysed response to Hsp90 inhibitors. These experiments confirm the results generated using the chemical inhibitors of Hsp70 expression. In conclusion, inhibiting drug-induced Hsp72 expression appears to overcome cellular resistance to Hsp90 inhibitors, supporting the clinical development of Hsp70 inhibitors and their combination with Hsp90 and proteasome inhibitors.

Suppression of FoxO1/cell death-inducing DNA fragmentation factor α-like effector A (Cidea) axis protects mouse β-cells against palmitic acid-induced apoptosis

2012 ◽  
Vol 348 (1) ◽  
pp. 297-304 ◽  
Author(s):  
Naoki Omae ◽  
Minoru Ito ◽  
Syoko Hase ◽  
Michiaki Nagasawa ◽  
Junichi Ishiyama ◽  
...  
Keyword(s):  
Cell Death ◽  
Palmitic Acid ◽  
Dna Fragmentation ◽  
Β Cells ◽  
Induced Apoptosis ◽  
Factor Α

Hypersensitivity of mtDNA-depleted cells to staurosporine-induced apoptosis: roles of Bcl-2 downregulation and cathepsin B

2011 ◽  
Vol 300 (5) ◽  
pp. C1090-C1106 ◽  
Author(s):  
Guillaume Rommelaere ◽  
Sébastien Michel ◽  
Ludovic Mercy ◽  
Antoine Fattaccioli ◽  
Catherine Demazy ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
B Cell ◽  
Dna Fragmentation ◽  
Cathepsin B ◽  
Caspase 3 ◽  
B Cell Lymphoma ◽  
Parental Cell Line ◽  
Induced Apoptosis ◽  
Parp 1

We show that mitochondrial DNA (mtDNA)-depleted 143B cells are hypersensitive to staurosporine-induced cell death as evidenced by a more pronounced DNA fragmentation, a stronger activation of caspase-3, an enhanced poly(ADP-ribose) polymerase-1 (PARP-1) cleavage, and a more dramatic cytosolic release of cytochrome c. We also show that B-cell CLL/lymphoma-2 (Bcl-2), B-cell lymphoma extra large (Bcl-XL), and myeloid cell leukemia-1 (Mcl-1) are constitutively less abundant in mtDNA-depleted cells, that the inhibition of Bcl-2 and Bcl-XL can sensitize the parental cell line to staurosporine-induced apoptosis, and that overexpression of Bcl-2 or Bcl-XL can prevent the activation of caspase-3 in ρ0143B cells treated with staurosporine. Moreover, the inactivation of cathepsin B with CA074-Me significantly reduced cytochrome c release, caspase-3 activation, PARP-1 cleavage, and DNA fragmentation in mtDNA-depleted cells, whereas the pan-caspase inhibitor failed to completely prevent PARP-1 cleavage and DNA fragmentation in these cells, suggesting that caspase-independent mechanisms are responsible for cell death even if caspases are activated. Finally, we show that cathepsin B is released in the cytosol of ρ0 cells in response to staurosporine, suggesting that the absence of mitochondrial activity leads to a facilitated permeabilization of lysosomal membranes in response to staurosporine.

Cell death and survival alterations in Malpighian tubules of Triatoma infestans following heat shock

2001 ◽  
Vol 79 (6) ◽  
pp. 709-717 ◽  
Author(s):  
Maria Luiza S. Mello ◽  
Maria Cristina H. Tavares ◽  
Marly M. Dantas ◽  
Vera Lúcia C.C. Rodrigues ◽  
Sílvya S. Maria-Engler ◽  
...  
Keyword(s):  
Cell Death ◽  
Heat Shock ◽  
Malpighian Tubules ◽  
Triatoma Infestans

scholarly journals Heat-Shocked Monocytes Are Resistant toStaphylococcus aureus-Induced Apoptotic DNA Fragmentation due to Expression of HSP72

1999 ◽  
Vol 67 (8) ◽  
pp. 4216-4222 ◽  
Author(s):  
Krzysztof Guzik ◽  
Małgorzata Bzowska ◽  
Jerzy Dobrucki ◽  
Juliusz Pryjma
Keyword(s):  
Heat Shock ◽  
Protective Effect ◽  
Dna Fragmentation ◽  
Human Peripheral Blood ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Monocyte Apoptosis ◽  
Induced Apoptosis ◽  
Hsp72 Expression ◽  
Antisense Oligomer

ABSTRACT Human peripheral blood monocytes became apoptotic following phagocytosis of Staphylococcus aureus. The consequences of heat stress for monocytes were studied with regard to the effect onS. aureus-induced apoptosis. Exposure of monocytes to 41.5°C for 1 h resulted in HSP72 expression and had no influence on phagocytosis of bacteria; moreover, phagocytosis of S. aureus immediately or shortly after heat shock had no effect on the S. aureus-induced monocyte apoptosis, as evidenced by DNA fragmentation assay. In contrast, cells which recovered from heat shock for 18 to 24 h, although active as phagocytes, were resistant to the S. aureus-induced apoptosis. The observed protective effect was related to the induction of HSP72, since blocking of HSP72 synthesis by an antisense oligomer abolished the protective effect of heat shock on bacterium-induced monocyte apoptosis.

Cell death and survival alterations in Malpighian tubules of Triatoma infestans following heat shock

2001 ◽  
Vol 79 (6) ◽  
pp. 709-717 ◽  
Author(s):  
Maria Luiza S Mello ◽  
Maria Cristina H Tavares ◽  
Marly M Dantas ◽  
Vera Lúcia CC Rodrigues ◽  
Sílvya S Maria-Engler ◽  
...  
Keyword(s):  
Cell Death ◽  
Heat Shock ◽  
Cell Survival ◽  
Malpighian Tubules ◽  
Triatoma Infestans ◽  
Blood Sucking ◽  
Short Period ◽  
Polyploid Cells ◽  
Shock Proteins ◽  
Cell Fusions

In this study, we examined cell survival and cell death in response to heat shock in an insect organ composed of highly polyploid cells no longer capable of cell division. For this, the frequency of nuclear phenotypes in Feulgen-stained Malpighian tubules of the blood-sucking insect, Triatoma infestans, was analyzed at various times after a short heat shock with or without subsequent moderate fasting. Cell death DNA fragmentation was studied immunocytochemically. Normal phenotypes and phenotypes indicative of cell survival (heterochromatin decondensation, nuclear fusion) and death (apoptosis, necrosis) were observed, especially in heat-shocked specimens. While the number of total and normal nuclei decreased following heat shock, the frequency of apoptosis increased during a short period (7 days) after heat shock. During a 30-day period following heat shock, the frequency of necrosis in fasted but not in fully nourished nymphs increased simultaneously with a decrease in the frequency of apoptosis. This finding suggests that the stress promoted by heat shock, but not that associated with heat shock plus fasting, can be dealt with by the apoptosis program. When considering the forms of cell survival, heterochromatin decondensation was more relevant in fully nourished nymphs, whereas nuclear and cell fusions were more important in fasted specimens. The forms of cell survival and cell death reported here may have protected the organ from damage by the stressing agents. In cells with no induction or accumulation of heat-shock proteins, cell death and the forms of cell survival observed here were the probable consequence.Key words: heat shock, fasting, apoptosis, necrosis, cell survival, Triatoma infestans.

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