Vitamin C inhibits FAS-induced apoptosis in monocytes and U937 cells

Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 336-343 ◽  
Author(s):  
Isabel Perez-Cruz ◽  
Juan M. Carcamo ◽  
David W. Golde
Keyword(s):  
Immune System ◽  
Vitamin C ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Membrane Integrity ◽  
Caspase 8 ◽  
Human Monocytes ◽  
Fas Receptor ◽  
Induced Apoptosis

Abstract The FAS receptor—FAS ligand system is a key apoptotic pathway for cells of the immune system. Ligation of the FAS-receptor (CD95) induces apoptosis by activation of pro—caspase-8 followed by downstream events, including an increase in reactive oxygen species (ROS) and the release of proapoptotic factors from the mitochondria, leading to caspase-3 activation. We investigated the role of vitamin C in FAS-mediated apoptosis and found that intracellular accumulation of pharmacologic concentrations of vitamin C inhibited FAS-induced apoptosis in the monocytic U937 cell line and in fresh human monocytes. Cells were loaded with vitamin C by exposure to dehydroascorbic acid (DHA), thereby circumventing in vitro artifacts associated with the poor transport and pro-oxidant effects of ascorbic acid (AA). Vitamin C inhibition of FAS-mediated apoptosis was associated with reduced activity of caspase-3, -8, and -10, as well as diminished levels of ROS and preservation of mitochondrial membrane integrity. Mechanistic studies indicated that the major effect of vitamin C was inhibition of the activation of caspase-8 with no effect on it enzymatic activity. An independent action of high intracellular concentrations of vitamin C on mitochondrial membrane stabilization was also detected. These studies illuminate the nature of redox-dependent signaling in FAS-induced apoptosis of human monocytes and suggest that vitamin C can modulate the immune system by inhibiting FAS-induced monocyte death. (Blood. 2003;102:336-343)

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.

scholarly journals Activation of caspase-8 in 3-deazaadenosine-induced apoptosis of U-937 cells occurs downstream of caspase-3 and caspase-9 without Fas receptor-ligand interaction

2001 ◽  
Vol 33 (4) ◽  
pp. 284-292 ◽  
Author(s):  
Yeo-Jin Chae ◽  
Ho-Shik Kim ◽  
Hyangshuk Rhim ◽  
Bo-Eun Kim ◽  
Seong-Whan Jeong ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Ligand Interaction ◽  
Receptor Ligand ◽  
Fas Receptor ◽  
Induced Apoptosis

scholarly journals Caspase-8 Activation Precedes Alterations of Mitochondrial Membrane Potential during Monocyte Apoptosis Induced by Phagocytosis and Killing of Staphylococcus aureus

2004 ◽  
Vol 72 (5) ◽  
pp. 2590-2597 ◽  
Author(s):  
Kazimierz Weęglarczyk ◽  
Jarosław Baran ◽  
Marek Zembala ◽  
Juliusz Pryjma
Keyword(s):  
Staphylococcus Aureus ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Human Peripheral Blood ◽  
Caspase 8 ◽  
Oxygen Intermediates ◽  
Monocyte Apoptosis

ABSTRACT Human peripheral blood monocytes become apoptotic following phagocytosis and killing of Staphylococcus aureus. Although this type of monocyte apoptosis is known to be initiated by Fas-Fas ligand (FasL) interactions, the downstream signaling pathway has not been determined. In this work the involvement of mitochondria and the kinetics of caspase-8 and caspase-3 activation after phagocytosis of S. aureus were studied. Caspase-8 activity was measured in cell lysates by using the fluorogenic substrate Ac-IETD-AFC. Active caspase-3 levels and mitochondrial membrane potential (Δψm) were measured in whole cells by flow cytometry using monoclonal antibodies reacting with activated caspase-3 and chloromethyl-X-rosamine, respectively. The results show that caspase-8 was activated shortly after phagocytosis of bacteria. Caspase-8 activation was followed by progressive disruption of Δψm, which is associated with the production of reactive oxygen intermediates. The irreversible caspase-8 inhibitor zIETD-FMK prevented the disruption of Δψm and the release of cytochrome c from S. aureus-exposed monocytes. Caspase-3 activation occurred following disruption of Δψm. These results strongly suggest that apoptosis of monocytes that have phagocytosed and killed S. aureus is driven by the Fas-FasL-initiated pathway, which is typical for type II cells.

Stem cell factor increases the expression of FLIP that inhibits IFNγ-induced apoptosis in human erythroid progenitor cells

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1324-1328 ◽  
Author(s):  
Ik-Joo Chung ◽  
Chunhua Dai ◽  
Sanford B. Krantz
Keyword(s):  
Stem Cell ◽  
Stem Cell Factor ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Interleukin 1 ◽  
Dominant Negative ◽  
Caspase 8 ◽  
Inhibitory Protein ◽  
Erythroid Progenitor ◽  
Induced Apoptosis

Interferon γ (IFNγ) acts on human erythroid colony-forming cells (ECFCs) to up-regulate Fas, without a demonstrable change of Fas ligand (FasL) or Fas-associated DD-containing protein (FADD) expression and activates caspase-8 plus caspase-3, which produce apoptosis. Our previous data showed that stem cell factor (SCF) reduced the inhibitory effect of IFNγ on human ECFCs when both factors were present in the cultures. However, the mechanism by which SCF prevents IFNγ-induced apoptosis in ECFCs is unclear. In this study we used highly purified human ECFCs to investigate the mechanism of the effect of SCF on IFNγ-induced apoptosis. Because the binding of FasL to Fas is the first step of the apoptosis cascade and IFNγ strongly up-regulates Fas expression, we added FasL (50 ng/mL) to the cultures with IFNγ to accentuate the IFNγ-induced activation of caspase-8 and caspase-3 plus subsequent apoptosis. SCF (100 ng/mL) clearly inhibited the activation of caspase-8 and caspase-3 induced by IFNγ and/or FasL, and it also reduced apoptosis as measured by the terminal dUTP nick-end labeling (TUNEL) assay. SCF did not decrease the surface expression of Fas on the ECFCs. FADD-like interleukin 1 β (IL-1β)–converting enzyme (FLICE)–inhibitory protein (FLIP) has been reported to interact with FADD and/or caspase-8 at the death-inducing signaling complex (DISC) level following Fas stimulation and acts as a dominant-negative caspase-8. SCF increased FLIP mRNA and protein expression, concomitant with reduced apoptosis, whereas IFNγ and/or FasL did not change FLIP expression. Reduction of FLIP expression with antisense oligonucleotides decreased the capacity of SCF to inhibit IFNγ-induced apoptosis, demonstrating a definite role for FLIP in the SCF-induced protection of ECFCs from IFNγ-initiated apoptosis.

scholarly journals Novel Subtilase Cytotoxin Produced by Shiga-Toxigenic Escherichia coli Induces Apoptosis in Vero Cells via Mitochondrial Membrane Damage

2009 ◽  
Vol 77 (7) ◽  
pp. 2919-2924 ◽  
Author(s):  
Gen Matsuura ◽  
Naoko Morinaga ◽  
Kinnosuke Yahiro ◽  
Reiko Komine ◽  
Joel Moss ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Membrane Damage ◽  
Annexin V ◽  
Vero Cells ◽  
Caspase 8 ◽  
Caspase Inhibitors ◽  
Induced Apoptosis ◽  
Subtilase Cytotoxin

ABSTRACT Subtilase cytotoxin (SubAB) is an AB5 cytotoxin produced by some strains of Shiga-toxigenic Escherichia coli. The A subunit is a subtilase-like serine protease and cleaves an endoplasmic reticulum chaperone, BiP, leading to transient inhibition of protein synthesis and cell cycle arrest at G1 phase. Here we show that SubAB, but not the catalytically inactive mutant SubAB(S272A), induced apoptosis in Vero cells, as detected by DNA fragmentation and annexin V binding. SubAB induced activation of caspase-3, -7, and -8. Caspase-3 appeared earlier than caspase-8, and by use of specific caspase inhibitors, it was determined that caspase-3 may be upstream of caspase-8. A general caspase inhibitor blocked SubAB-induced apoptosis, detected by annexin V binding. SubAB also stimulated cytochrome c release from mitochondria, which was not suppressed by caspase inhibitors. In HeLa cells, Apaf-1 small interfering RNA inhibited caspase-3 activation, suggesting that cytochrome c might form an apoptosome, leading to activation of caspase-3. These data suggested that SubAB induced caspase-dependent apoptosis in Vero cells through mitochondrial membrane damage.

Suppression of Fas-Mediated Signaling Pathway is Involved in Zinc Inhibition of Ethanol-Induced Liver Apoptosis

2003 ◽  
Vol 228 (4) ◽  
pp. 406-412 ◽  
Author(s):  
Jason C. Lambert ◽  
Zhanxiang Zhou ◽  
Y. James Kang
Keyword(s):  
Electron Microscopy ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Morphological Changes ◽  
Alcohol Exposure ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Caspase 8 ◽  
Intragastric Administration ◽  
Induced Apoptosis ◽  
Zinc Inhibition

Apoptosis is critically involved in hepatic pathogenesis induced by acute alcohol exposure. This study was undertaken to test the hypothesis that zinc interferes with an important Fas ligand-mediated pathway in the liver, leading to the inhibition of ethanol-induced apoptosis. Male 129/SvPCJ mice were injected subcutaneously with ZnSO4 (5 mg of Zn ion/kg) in 12-hr intervals for 24 hr before intragastric administration of ethanol (5 g/kg) in 12-hr intervals for 36 hr. Ethanol-induced apoptosis in the liver was detected by a terminal deoxynucleotidyl transferase nick-end labeling assay and was further confirmed by electron microscopy. The number of apoptotic cells in the livers pretreated with zinc was significantly decreased, being only 15% of that found in the animals treated with ethanol only. Characteristic apoptotic morphological changes observed by electron microscopy were also inhibited by zinc. Importantly, zinc inhibited ethanol-induced activation of caspase-3, the primary executioner protease responsible for alcohol-induced liver apoptosis, and caspase-8 as determined by enzymatic assay. Immunohistochemical analysis revealed that zinc inhibited ethanol-induced endogenous Fas ligand activation, which is a key component in signaling pathways leading to hepatic caspase-8 and subsequent caspase-3 activation and apoptosis. These results demonstrate that zinc is a potent inhibitor of acute ethanol-induced liver apoptosis, and this effect occurs primarily through zinc interference with Fas ligand pathway and the suppression of caspase-3.

scholarly journals Cleavage by Caspase 8 and Mitochondrial Membrane Association Activate the BH3-only Protein Bid during TRAIL-induced Apoptosis

2016 ◽  
Vol 291 (22) ◽  
pp. 11843-11851 ◽  
Author(s):  
Kai Huang ◽  
Jingjing Zhang ◽  
Katelyn L. O'Neill ◽  
Channabasavaiah B. Gurumurthy ◽  
Rolen M. Quadros ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Caspase 8 ◽  
Membrane Association ◽  
Induced Apoptosis

scholarly journals Inclusion Complex of Zerumbone with Hydroxypropyl-β-Cyclodextrin Induces Apoptosis in Liver Hepatocellular HepG2 Cells via Caspase 8/BID Cleavage Switch and Modulating Bcl2/Bax Ratio

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Nabilah Muhammad Nadzri ◽  
Ahmad Bustamam Abdul ◽  
Mohd Aspollah Sukari ◽  
Siddig Ibrahim Abdelwahab ◽  
Eltayeb E. M. Eid ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
Mitochondrial Membrane ◽  
Morphological Study ◽  
Caspase 3 ◽  
Anticancer Agent ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Solubility In Water ◽  
Anticancer Effects ◽  
First Time

Zerumbone (ZER) isolated fromZingiber zerumbetwas previously encapsulated with hydroxypropyl-β-cyclodextrin (HPβCD) to enhance ZER’s solubility in water, thus making it highly tolerable in the human body. The anticancer effects of this new ZER-HPβCD inclusion complex via apoptosis cell death were assessed in this study for the first time in liver hepatocellular cells, HepG2. Apoptosis was ascertained by morphological study, nuclear stain, and sub-G1 cell population accumulation with G2/M arrest. Further investigations showed the release of cytochrome c and loss of mitochondrial membrane potential, proving mitochondrial dysfunction upon the ZER-HPβCD treatment as well as modulating proapoptotic and anti-apototic Bcl-2 family members. A significant increase in caspase 3/7, caspase 9, and caspase 8 was detected with the depletion of BID cleaved by caspase 8. Collectively, these results prove that a highly soluble inclusion complex of ZER-HPβCD could be a promising anticancer agent for the treatment of hepatocellular carcinoma in humans.

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.

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