scholarly journals Sendai Virus Infection Induces Apoptosis through Activation of Caspase-8 (FLICE) and Caspase-3 (CPP32)

1999 ◽  
Vol 73 (1) ◽  
pp. 702-708 ◽  
Author(s):  
Michael Bitzer ◽  
Florian Prinz ◽  
Manuel Bauer ◽  
Martin Spiegel ◽  
Wolfgang J. Neubert ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Cell Injury ◽  
Sendai Virus ◽  
Host Cells ◽  
Target Cells ◽  
Caspase 8 ◽  
Proteolytic Activation ◽  
Caspase Family ◽  
Infected Cells ◽  
Induced Apoptosis

ABSTRACT Sendai virus (SV) infection and replication lead to a strong cytopathic effect with subsequent death of host cells. We now show that SV infection triggers an apoptotic program in target cells. Incubation of infected cells with the peptide inhibitor z-VAD-fmk abrogated SV-induced apoptosis, indicating that proteases of the caspase family were involved. Moreover, proteolytic activation of two distinct caspases, CPP32/caspase-3 and, as shown for the first time in virus-infected cells, FLICE/caspase-8, could be detected. So far, activation of FLICE/caspase-8 has been described in apoptosis triggered by death receptors, including CD95 and tumor necrosis factor (TNF)-R1. In contrast, we could show that SV-induced apoptosis did not require TNF or CD95 ligand. We further found that apoptosis of infected cells did not influence the maturation and budding of SV progeny. In conclusion, SV-induced cell injury is mediated by CD95- and TNF-R1-independent activation of caspases, leading to the death of host cells without impairment of the viral life cycle.

scholarly journals Role of Bcl-2 Family Members in Caspase-Independent Apoptosis during Chlamydia Infection

2002 ◽  
Vol 70 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Jean-Luc Perfettini ◽  
John C. Reed ◽  
Nicole Israël ◽  
Jean-Claude Martinou ◽  
Alice Dautry-Varsat ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Chlamydia Psittaci ◽  
Host Cells ◽  
Chlamydia Infection ◽  
Caspase Inhibitor ◽  
Obligate Intracellular Bacterium ◽  
Obligate Intracellular ◽  
Infected Cells ◽  
Induced Apoptosis

ABSTRACT Infection with an obligate intracellular bacterium, the Chlamydia trachomatis lymphogranuloma venereum (LGV/L2) strain or the guinea pig inclusion conjunctivitis serovar of Chlamydia psittaci, leads to apoptosis of host cells. The apoptosis is not affected by a broad-spectrum caspase inhibitor, and caspase-3 is not activated in infected cells, suggesting that apoptosis mediated by these two strains of Chlamydia is independent of known caspases. Overexpression of the proapoptotic Bcl-2 family member, Bax, was previously shown to induce caspase-independent apoptosis, and we find that Bax is activated and translocates from the cytosol to the mitochondria in C. psittaci-infected cells. C. psittaci-induced apoptosis is inhibited in host cells overexpressing Bax inhibitor-1 and is inhibited through overexpression of Bcl-2, which blocks both caspase-dependent and -independent apoptosis. As Bax and mitochondria are ideally located to sense stress-related metabolic changes emanating from the interior of an infected cell, it is likely that Bax-dependent apoptosis may also be observed in cells infected with other intracellular pathogens.

scholarly journals Leptospira interrogans Induces Apoptosis in Macrophages via Caspase-8- and Caspase-3-Dependent Pathways

2008 ◽  
Vol 77 (2) ◽  
pp. 799-809 ◽  
Author(s):  
Dandan Jin ◽  
David M. Ojcius ◽  
Dexter Sun ◽  
Haiyan Dong ◽  
Yihui Luo ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Host Cells ◽  
Caspase 8 ◽  
Lamin A ◽  
Leptospira Interrogans ◽  
Dependent Manner ◽  
Caspase 9 ◽  
Caspase 6 ◽  
Induced Apoptosis

ABSTRACT Apoptosis of host cells plays an important role in modulating the pathogenesis of many infectious diseases. It has been reported that Leptospira interrogans, the causal agent of leptospirosis, induces apoptosis in macrophages and hepatocytes. However, the molecular mechanisms responsible for host cell death remained largely unknown. Here we demonstrate that L. interrogans induced apoptosis in a macrophage-like cell line, J774A.1, and primary murine macrophages in a time- and dose-dependent manner. Apoptosis was associated with the activation of cysteine aspartic acid-specific proteases (caspase-3, caspase-6, and caspase-8), the increased expression of Fas-associated death domain (FADD), and the cleavage of the caspase substrates poly(ADP-ribose) polymerase (PARP) and nuclear lamina protein (lamin A and lamin C). Caspase-9 was activated to a lesser extent, whereas no release of cytochrome c from mitochondria was detectable. Inhibition of caspase-8 impaired L. interrogans-induced caspase-3 and -6 activation, as well as PARP and lamin A/C cleavage and apoptosis, suggesting that apoptosis is initiated via caspase-8 activation. Furthermore, caspase-3 was required for the activation of caspase-6 and seemed to be involved in caspase-9 activation through a feedback amplification loop. These data indicate that L. interrogans-induced apoptosis in macrophages is mediated by caspase-3 and -6 activation through a FADD-caspase-8-dependent pathway, independently of mitochondrial cytochrome c-caspase-9-dependent signaling.

scholarly journals Characterization of a Previously Unidentified Viral Protein in Porcine Circovirus Type 2-Infected Cells and Its Role in Virus-Induced Apoptosis

2005 ◽  
Vol 79 (13) ◽  
pp. 8262-8274 ◽  
Author(s):  
Jue Liu ◽  
Isabelle Chen ◽  
Jimmy Kwang
Keyword(s):  
Viral Replication ◽  
Caspase 3 ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Caspase 8 ◽  
Infected Cells ◽  
Apoptotic Activity ◽  
Induced Apoptosis

ABSTRACT Porcine circovirus type 2 (PCV2) is the causative agent of postweaning multisystemic wasting syndrome in pigs. In this study, transcription and translation of a novel viral gene (termed ORF3 here) was detected during productive infection of PCV2 in PK15 cells. The results of infection with ORF3-deficient PCV2 by site-directed mutagenesis indicated that the protein is not essential for viral replication. To investigate the underlying mechanism of cell death caused by replication of PCV2, apoptosis characterized by chromosomal condensation and fragmentation, formation of apoptotic bodies, and significant increase in hypodiploids were detected in infected cells. We further demonstrated that PCV2-induced apoptosis required the activation of caspase-8 but not caspase-9. The activation of caspase-8 results in the activation of caspase-3 as shown by an increase in the cleavage of the caspase substrate in the infected cells. To determine whether ORF3 protein could trigger apoptosis, ORF3 as well as ORF1 and ORF2 genes were transiently expressed in PK15 and Cos-7 cells for apoptotic activity assay. Transfection of cells with the ORF3 alone induced apoptosis using a pathway similar to that described in the context of viral infection. This is further confirmed by a significant decrease in apoptotic activity of infected cells in the absence of the ORF3 expression, suggesting that the protein plays a major role in the induction of virus-induced apoptosis. Altogether, these results indicate that ORF3 is a novel PCV2 protein that is not essential for viral replication in cultured cells but is involved in PCV2-induced apoptosis by activating caspase-8 and caspase-3 pathways.

scholarly journals Azithromycin Promotes the Osteogenic Differentiation of Human Periodontal Ligament Stem Cells after Stimulation with TNF-α

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Tingting Meng ◽  
Ying Zhou ◽  
Jingkun Li ◽  
Meilin Hu ◽  
Xiaomeng Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Alkaline Phosphatase ◽  
Osteogenic Differentiation ◽  
Alkaline Phosphatase Activity ◽  
Periodontal Ligament ◽  
Caspase 3 ◽  
Caspase 8 ◽  
Periodontal Ligament Stem Cells ◽  
Alizarin Red ◽  
Induced Apoptosis

Background and Objective. This study investigated the effects and underlying mechanisms of azithromycin (AZM) treatment on the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) after their stimulation with TNF-α in vitro. Methods. PDLSCs were isolated from periodontal ligaments from extracted teeth, and MTS assay was used to evaluate whether AZM and TNF-α had toxic effects on PDLSCs viability and proliferation. After stimulating PDLSCs with TNF-α and AZM, we analyzed alkaline phosphatase staining, alkaline phosphatase activity, and alizarin red staining to detect osteogenic differentiation. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the mRNA expression of osteogenic-related genes, including RUNX2, OCN, and BSP. Western blotting was used to measure the NF-κB signaling pathway proteins p65, phosphorylated p65, IκB-α, phosphorylated IκB-α, and β-catenin as well as the apoptosis-related proteins caspase-8 and caspase-3. Annexin V assay was used to detect PDLSCs apoptosis. Results. TNF-α stimulation of PDLSCs decreased alkaline phosphatase and alizarin red staining, alkaline phosphatase activity, and mRNA expression of RUNX2, OCN, and BSP in osteogenic-conditioned medium. AZM enhanced the osteogenic differentiation of PDLSCs that were stimulated with TNF-α. Western blot analysis showed that β-catenin, phosphorated p65, and phosphorylated IκB-α protein expression decreased in PDLSCs treated with AZM. In addition, pretreatment of PDLSCs with AZM (10 μg/ml, 20 μg/ml) prevented TNF-α-induced apoptosis by decreasing caspase-8 and caspase-3 expression. Conclusions. Our results showed that AZM promotes PDLSCs osteogenic differentiation in an inflammatory microenvironment by inhibiting the WNT and NF-κB signaling pathways and by suppressing TNF-α-induced apoptosis. This suggests that AZM has potential as a clinical therapeutic for periodontitis.

scholarly journals Granzyme B Short-Circuits the Need for Caspase 8 Activity during Granule-Mediated Cytotoxic T-Lymphocyte Killing by Directly Cleaving Bid

2000 ◽  
Vol 20 (11) ◽  
pp. 3781-3794 ◽  
Author(s):  
Michele Barry ◽  
Jeffrey A. Heibein ◽  
Michael J. Pinkoski ◽  
Siow-Fong Lee ◽  
Richard W. Moyer ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Caspase 3 ◽  
Cytotoxic T Lymphocyte ◽  
Granzyme B ◽  
Serine Proteinase ◽  
Target Cells ◽  
Caspase 8 ◽  
Intact Cells ◽  
Whole Cells

ABSTRACT Cytotoxic T lymphocytes (CTL) can trigger an apoptotic signal through the Fas receptor or by the exocytosis of granzyme B and perforin. Caspase activation is an important component of both pathways. Granzyme B, a serine proteinase contained in granules, has been shown to proteolytically process and activate members of the caspase family in vitro. In order to gain an understanding of the contributions of caspases 8 and 3 during granule-induced apoptosis in intact cells, we have used target cells that either stably express the rabbitpox virus-encoded caspase inhibitor SPI-2 or are devoid of caspase 3. The overexpression of SPI-2 in target cells significantly inhibited DNA fragmentation, phosphatidylserine externalization, and mitochondrial disruption during Fas-mediated cell death. In contrast, SPI-2 expression in target cells provided no protection against granzyme-mediated apoptosis, mitochondrial collapse, or cytolysis, leading us to conclude that SPI-2-inhibited caspases are not an essential requirement for the granzyme pathway. Caspase 3-deficient MCF-7 cells were found to be resistant to CTL-mediated DNA fragmentation but not to CTL-mediated cytolysis and loss of the mitochondrial inner membrane potential. Furthermore, we demonstrate that granzyme B directly cleaves the proapoptotic molecule Bid, bypassing the need for caspase 8 activation of Bid. These results provide evidence for a two-pronged strategy for mediating target cell destruction and provide evidence of a direct link between granzyme B activity, Bid cleavage, and caspase 3 activation in whole cells.

The role of caspase family protease, caspase-3 on cisplatin-induced apoptosis in cisplatin-resistant A431 cell line

2000 ◽  
Vol 46 (3) ◽  
pp. 241-245 ◽  
Author(s):  
Hiroshi Mese ◽  
Akira Sasaki ◽  
Shuko Nakayama ◽  
Rafael E. Alcalde ◽  
Tomohiro Matsumura
Keyword(s):  
Cell Line ◽  
Caspase 3 ◽  
A431 Cell ◽  
Caspase Family ◽  
A431 Cell Line ◽  
Induced Apoptosis

scholarly journals Autoregulatory Feedback Mechanism of P38MAPK/Caspase-8 in Photodynamic Therapy-Hydrophilic/Lipophilic Tetra-α-(4-carboxyphenoxy) Phthalocyanine Zinc-Induced Apoptosis of Human Hepatocellular Carcinoma Bel-7402 Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yu Wang ◽  
Chunhui Xia ◽  
Wei Chen ◽  
Yuhang Chen ◽  
Yiyi Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Photodynamic Therapy ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Human Hepatocellular Carcinoma ◽  
Caspase 8 ◽  
Induced Apoptosis

Photodynamic therapy (PDT) is a novel and promising antitumor treatment. Our previous study showed that hydrophilic/lipophilic tetra-α-(4-carboxyphenoxy) phthalocyanine zinc- (TαPcZn-) mediated PDT (TαPcZn-PDT) inhibits the proliferation of human hepatocellular carcinoma Bel-7402 cells by triggering apoptosis and arresting cell cycle. However, mechanisms of TαPcZn-PDT-induced apoptosis of Bel-7402 cells have not been fully clarified. In the present study, therefore, effect of TαPcZn-PDT on apoptosis, P38MAPK, p-P38MAPK, Caspase-8, Caspase-3, Bcl-2, Bid, Cytochrome c, and mitochondria membrane potential in Bel-7402 cells without or with P38MAPK inhibitor SB203580 or Caspase-8 inhibitor Ac-IEFD-CHO was investigated by haematoxylin and eosin (HE) staining assay, flow cytometry analysis of annexin V-FITC/propidium iodide (PI) double staining cells and 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide (JC-1), and immunoblot assay. We found that TαPcZn-PDT resulted in apoptosis induction, activation of P38MAPK, Caspase-8, Caspase-3, and Bid, downregulation of Bcl-2, release of Cytochrome c from mitochondria, and disruption of mitochondrial membrane potential in TαPcZn-PDT-treated Bel-7402 cells. In contrast, SB203580 or Ac-IEFD-CHO attenuated induction of apoptosis, activation of P38MAPK, Caspase-8, Caspase-3, and Bid, downregulation of Bcl-2, release of Cytochrome c from mitochondria, and disruption of mitochondrial membrane potential in TαPcZn-PDT-treated Bel-7402 cells. Taken together, we conclude that Caspase-3, Bcl-2, Bid, and mitochondria are involved in autoregulatory feedback of P38MAPK/Caspase-8 during TαPcZn-PDT-induced apoptosis of Bel-7402 cells.

Apoptotic signalling cascade in photosensitized human epidermal carcinoma A431 cells: involvement of singlet oxygen, c-Jun N-terminal kinase, caspase-3 and p21-activated kinase 2

2000 ◽  
Vol 351 (1) ◽  
pp. 221-232 ◽  
Author(s):  
Wen-Hsiung CHAN ◽  
Jau-Song YU ◽  
Shiaw-Der YANG
Keyword(s):  
Singlet Oxygen ◽  
Caspase 3 ◽  
Early Stage ◽  
A431 Cells ◽  
Caspase Family ◽  
P21 Activated Kinase ◽  
Induced Apoptosis ◽  
Jnk Activation ◽  
Epidermal Carcinoma ◽  
Signalling Cascade

Photodynamic treatment (PDT) elicits diverse cellular responses and can also cause apoptosis. In the present study the cascade of signalling events involved in PDT-induced apoptosis was investigated using Rose Bengal (RB) as the photosensitizer, and human epidermal carcinoma A431 cells as the cell model. We show that a 36-kDa kinase detected by an in-gel kinase assay is markedly activated during PDT-triggered apoptosis. Immunoblot analysis revealed that this 36-kDa kinase represents the C-terminal catalytic fragment of p21-activated kinase (PAK)2. Generation of this active fragment of PAK2 is mediated by the caspase family of proteases, which are activated by PDT. The specific caspase inhibitors (acetyl-Asp-Glu-Val-Asp-aldehyde and acetyl-Tyr-Val-Ala-Asp-chloromethylketone) block the PDT-induced caspase-3 activation and subsequent PAK2 cleavage/activation, indicating a major role for the caspase family proteases in PDT-induced apoptosis. Both PDT-induced caspase-3 activation and PAK2 cleavage/activation can be inhibited by the singlet oxygen scavengers, L-histidine and α-tocopherol, but not the hydroxyl radical scavenger, mannitol, demonstrating that singlet oxygen is an immediate early-apoptotic signal generated by PDT. In addition, PDT can induce a two-stage activation of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) in A431 cells; the early-stage JNK activation is singlet oxygen-dependent, whereas the late-stage JNK activation is mediated by the singlet oxygen-triggered caspase activation. Experiments using anti-sense oligonucleotides against JNK1 and PAK2 further show that during PDT-induced apoptosis the early-stage JNK activation is required for caspase activation, and that the late-stage JNK activation is regulated by the caspase-mediated cleavage/activation of PAK2. Collectively, a model for the PDT-triggered apoptotic signalling cascade with RB is proposed, which involves singlet oxygen, JNK, caspase-3 and PAK2, sequentially.

SMAC-Mimetic BV-6 Sensitizes Therapeutic Agents-Induced Apoptosis In AML Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2177-2177
Author(s):  
Duncan H Mak ◽  
Christa Manton ◽  
Michael Andreeff ◽  
Bing Z Carter
Keyword(s):  
Cell Death ◽  
Vector Control ◽  
Caspase 3 ◽  
Jurkat Cells ◽  
Leukemic Cells ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Smac Mimetic ◽  
P53 Activation ◽  
Induced Apoptosis

Abstract Abstract 2177 The antiapoptotic function of the inhibitors of apoptosis family of proteins (IAPs) is antagonized by mitochondria-released SMAC protein. The IAP-member XIAP suppresses apoptosis by directly binding and inhibiting caspase-9 and caspase-3, while cIAP1, a component of the cytoplasmic signaling complex containing TNF receptor associated factors, suppresses apoptosis via the caspase-8-mediated pathway. BV-6 (Genentech) is a bivalent SMAC-mimetic and has been shown to promote cell death by inducing cIAP autoubiquitination, NF-κB activation, and TNFα-dependent apoptosis. We examined its effect on leukemic cells and found that BV-6 only moderately induced apoptosis. The EC50 was found to be 15.3±5.1 μM at 48 hours in OCI-AML3 cells which are relatively sensitive. We then determined whether BV-6 sensitizes leukemic cells to the HDM2-inhibitor nutlin-3a and to Ara-C. p53 modulates the expression and activity of Bcl-2 family proteins and promotes the mitochondrial-mediated apoptosis. We showed previously that activation of p53 by nutlin-3a sensitizes AML cells to XIAP inhibition induced-death in part by promoting the release of SMAC from mitochondrion (Carter BZ et al., Blood 2010). We treated OCI-AML3 cells with BV-6, nutlin-3a or Ara-C, and BV-6+nutlin-3a or BV-6+Ara-C and found that the combination of BV-6 and nutlin-3a or BV-6 and Ara-C synergistically induced cell death in OCI-AML3 cells with a combination index (CI) of 0.27±0.11 and 0.22±0.05 (48 hours), respectively. To demonstrate that p53 activation is essential for the synergism of BV-6+nutlin-3a combination, we treated OCI-AML3 vector control and p53 knockdown cells with these two agents and found that the combination synergistically promoted cell death in the vector control (CI=0.47±0.15) but not in the p53 knockdown cells, as expected, while BV6+Ara-C was synergistic in both vector control and p53 knockdown cells (CI=0.15±0.03 and 0.08±0.03, respectively, 48 hours). BV-6 induced activation of caspase-8, caspase-9, and caspase-3 and decreased XIAP levels, but did not cause rapid cIAP1 degradation, as reported by others. To assess the contribution of death receptor-mediated apoptosis in BV-6-induced cell death, we treated Jurkat and caspase-8 mutated Jurkat cells (JurkatI9.2) with BV-6 and found that BV-6 induced cell death and significantly potentiated TRAIL-induced apoptosis in Jurkat cells (CI=0.14±0.08, 48 hours). Caspase-8 mutated JurkatI9.2 cells were significantly less sensitive to BV-6 than Jurkat cells and as expected, JurkatI9.2 was completely resistant to TRAIL. Collectively, we showed that the bivalent SMAC-mimetic BV-6 potentiates p53 activation-, chemotherapy-, and TRAIL-induced cell death, but has only minimal activity by itself in leukemic cells. SMAC-mimetics could be useful in enhancing the efficacy of different classes of therapeutic agents used in AML therapy. Disclosures: No relevant conflicts of interest to declare.

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