benzyloxycarbonylvalyl-alanyl-aspartyl-fluoromethyl-ketone and 4-(2-aminoethyl)benzenesulfonylfluoride
benzyloxycarbonylvalyl-alanyl-aspartyl-fluoromethyl-ketone has been researched along with 4-(2-aminoethyl)benzenesulfonylfluoride* in 4 studies
Other Studies
4 other study(ies) available for benzyloxycarbonylvalyl-alanyl-aspartyl-fluoromethyl-ketone and 4-(2-aminoethyl)benzenesulfonylfluoride
Article | Year |
---|---|
Apoptosis of human neutrophils induced by protein phosphatase 1/2A inhibition is caspase-independent and serine protease-dependent.
Protein phosphatase (PP) activity is associated with the regulation of apoptosis in neutrophils. However, the underlying regulatory mechanism(s) in apoptosis remain unclear. The type of cell death induced by okadaic acid (OA), the inhibitor of PP1 and PP2A, is characterized by apoptotic morphological changes of the cells and annexin V-positive staining without DNA fragmentation. The apoptotic effects of OA and calyculin A on neutrophils were observed at concentrations ranging from 50 to 200 nM, or 10 to 50 nM, respectively. Cyclosporine A (a PP2B specific inhibitor), however, did not exhibit any pro-apoptotic effects. OA and calyculin A, but not cyclosporine A, exhibited significant effects on protein levels and on the electrophoretic mobility of Mcl-1. zVAD-fmk, a pancaspase inhibitor, failed to inhibit the effect of OA on the caspase-3 activity, procaspase-3 processing, and the apoptotic rate of neutrophils. However, 4-(2-aminoethyl) benzenesulfonylfluoride (AEBSF), a general serine protease inhibitor, significantly abrogated the OA-induced mobility shift in procaspase-3, caspase-3 activation, and the apoptotic morphological changes in neutrophils. Moreover, OA enhanced the serine protease activity of the neutrophils. The addition of the proteinase-3 protein increased the rate of neutrophil apoptosis, which was also blocked by AEBSF but not by zVAD-fmk. These results suggest that OA induces procaspase-3 processing but that OA-induced apoptosis is caspase-independent and serine protease-dependent. Topics: Amino Acid Chloromethyl Ketones; Apoptosis; Apoptosis Inducing Factor; Caspase 3; Cells, Cultured; Cyclosporine; Cysteine Proteinase Inhibitors; Dose-Response Relationship, Drug; Enzyme Inhibitors; Humans; Marine Toxins; Myeloblastin; Neutrophils; Okadaic Acid; Oxazoles; Phosphoprotein Phosphatases; Protein Kinase C-alpha; Protein Kinase Inhibitors; Protein Phosphatase 1; Serine Endopeptidases; Serine Proteinase Inhibitors; Sulfones; Time Factors | 2007 |
Serine proteases mediate apoptosis-like cell death and phagocytosis under caspase-inhibiting conditions.
Effective execution of apoptosis requires the activation of caspases. However, in many cases, broad-range caspase inhibitors such as Z-VAD.fmk do not inhibit cell death because death signaling continues via basal caspase activities or caspase-independent processes. Although death mediators acting under caspase-inhibiting conditions have been identified, it remains unknown whether they trigger a physiologically relevant cell death that shows typical signs of apoptosis, including phosphatidylserine (PS) exposure and the removal of apoptotic cells by phagocytosis. Here we show that cells treated with ER stress drugs or deprived of IL-3 still show hallmarks of apoptosis such as cell shrinkage, membrane blebbing, mitochondrial release of cytochrome c, PS exposure and phagocytosis in the presence of Z-VAD.fmk. Cotreatment of the stressed cells with Z-VAD.fmk and the serine protease inhibitor Pefabloc (AEBSF) inhibited all these events, indicating that serine proteases mediated the apoptosis-like cell death and phagocytosis under these conditions. The serine proteases were found to act upstream of an increase in mitochondrial membrane permeability as opposed to the serine protease Omi/HtrA2 which is released from mitochondria at a later stage. Thus, despite caspase inhibition or basal caspase activities, cells can still be phagocytosed and killed in an apoptosis-like fashion by a serine protease-mediated mechanism that damages the mitochondrial membrane. Topics: Amino Acid Chloromethyl Ketones; Animals; Antibodies, Monoclonal; Apoptosis; Blotting, Western; Brefeldin A; Caspase 3; Caspase Inhibitors; Caspases; Cell Adhesion; Cell Line, Tumor; Cycloheximide; fas Receptor; Fibroblasts; Flow Cytometry; Gene Expression Regulation; HeLa Cells; Humans; Interleukin-3; Mice; Microscopy, Fluorescence; Microscopy, Phase-Contrast; Models, Biological; Phagocytosis; Proto-Oncogene Proteins c-bcl-2; Rats; Serine Endopeptidases; Sulfones; Thapsigargin; Tunicamycin; U937 Cells | 2003 |
A serine protease is involved in the initiation of DNA damage-induced apoptosis.
Caspases are considered to be the key effector proteases of apoptosis. Initiator caspases cleave and activate downstream executioner caspases, which are responsible for the degradation of numerous cellular substrates. We studied the role of caspases in apoptotic cell death of a human melanoma cell line. Surprisingly, the pancaspase inhibitor zVAD-fmk was unable to block cleavage of poly(ADP-ribose) polymerase (PARP) after treatment with etoposide, while it did prevent DEVDase activity. It is highly unlikely that caspase-2, which is a relatively zVAD-fmk-resistant caspase, is mediating etoposide-induced PARP cleavage, as a preferred inhibitor of this caspase could not prevent cleavage. In contrast, caspase activation and PARP degradation were blocked by pretreatment of the cells with the serine protease inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF). We therefore conclude that a serine protease regulates an alternative initiation mechanism that leads to caspase activation and PARP cleavage. More importantly, while zVAD-fmk could not rescue melanoma cells from etoposide-induced death, the combination with AEBSF resulted in substantial protection. This indicates that this novel pathway fulfills a critical role in the execution of etoposide-induced programmed cell death. Topics: Amino Acid Chloromethyl Ketones; Animals; Apoptosis; Blotting, Western; Caspase 2; Caspase 3; Caspase Inhibitors; Caspases; Cell Line; Cell Line, Tumor; Coumarins; Cysteine Proteinase Inhibitors; DNA Damage; Etoposide; Fibroblasts; Flow Cytometry; Humans; Microscopy, Phase-Contrast; Oligopeptides; Peptide Hydrolases; Poly(ADP-ribose) Polymerases; Rats; Serine Endopeptidases; Serine Proteinase Inhibitors; Sulfones; Tumor Necrosis Factor-alpha | 2003 |
The c-Myc-interacting adaptor protein Bin1 activates a caspase-independent cell death program.
Cell death processes are progressively inactivated during malignant development, in part by loss of tumor suppressors that can promote cell death. The Bin1 gene encodes a nucleocytosolic adaptor protein with tumor suppressor properties, initially identified through its ability to interact with and inhibit malignant transformation by c-Myc and other oncogenes. Bin1 is frequently missing or functionally inactivated in breast and prostate cancers and in melanoma. In this study, we show that Bin1 engages a caspase-independent cell death process similar to type II apoptosis, characterized by cell shrinkage, substratum detachment, vacuolated cytoplasm, and DNA degradation. Cell death induction was relieved by mutation of the BAR domain, a putative effector domain, or by a missplicing event that occurs in melanoma and inactivates suppressor activity. Cells in all phases of the cell cycle were susceptible to death and p53 and Rb were dispensable. Notably, Bin1 did not activate caspases and the broad spectrum caspase inhibitor ZVAD.fmk did not block cell death. Consistent with the lack of caspase involvement, dying cells lacked nucleosomal DNA cleavage and nuclear lamina degradation. Moreover, neither Bcl-2 or dominant inhibition of the Fas pathway had any effect. In previous work, we showed that Bin1 could not suppress cell transformation by SV40 large T antigen. Consistent with this finding, we observed that T antigen suppressed the death program engaged by Bin1. This observation was interesting in light of emerging evidence that T antigen has roles in cell immortalization and human cell transformation beyond Rb and p53 inactivation. In support of a link to c-Myc-induced death processes, AEBSF, a serine protease inhibitor that inhibits apoptosis by c-Myc, potently suppressed DNA degradation by Bin1. Our findings suggest that the tumor suppressor activity of Bin1 reflects engagement of a unique cell death program. We propose that loss of Bin1 may promote malignancy by blunting death penalties associated with oncogene activation. Topics: Adaptor Proteins, Signal Transducing; Amino Acid Chloromethyl Ketones; Antigens, Polyomavirus Transforming; Apoptosis; Bone Neoplasms; Carcinoma, Hepatocellular; Carrier Proteins; Caspases; Cell Adhesion; Cell Size; Cell Transformation, Neoplastic; Cysteine Proteinase Inhibitors; DNA Fragmentation; Enzyme Activation; fas Receptor; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Mitochondria; Nuclear Proteins; Osteosarcoma; Protein Structure, Tertiary; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Recombinant Fusion Proteins; Retinoblastoma Protein; Serine Proteinase Inhibitors; Sulfones; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Tumor Suppressor Proteins | 2000 |