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Pan-caspase Inhibitor (pan-caspase + inhibitor)
Selected AbstractsHyaluronan-binding peptide can inhibit tumor growth by interacting with Bcl-2INTERNATIONAL JOURNAL OF CANCER, Issue 1 2004Ninfei Liu Abstract Previous studies have indicated that proteins that bind hyaluronan can also inhibit the growth of tumor cells. To determine if synthetic peptides also possessed these properties, we tested a series of polypeptides containing structural motifs from different proteins for their ability to bind [3H]hyaluronan, and identified one compound termed P4 that had a particularly strong interaction. Further studies revealed that P4 also inhibited the growth of tumor cells in tissue culture as well as on the chorioallantoic membranes of chicken embryos. In addition, expression vectors for P4 caused tumor cells to grow slower in nude mice and reduced their vascularization. The P4 peptide also inhibited VEGF-induced angiogenesis in the chorioallantoic membranes of chicken embryos. Studies on cultured cells indicated that P4 induced apoptosis, which was blocked by a pan-caspase inhibitor. Confocal microscopy revealed that shortly after its uptake, P4 became associated with mitochondria. Immunoprecipitation indicated that P4 could bind to Bcl-2 and Bcl-xL, which are associated with mitochondria and regulate apoptosis. This was also supported by the fact that P4 induced the release of cytochrome c from preparations of mitochondria. Taken together, these results suggest that P4 binds to Bcl-2 and related proteins and this activates the apoptotic cascade. © 2003 Wiley-Liss, Inc. [source] Early nuclear exclusion of the transcription factor max is associated with retinal ganglion cell death independent of caspase activityJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2004Hilda Petrs-Silva We examined the behavior of the transcription factor Max during retrograde neuronal degeneration of retinal ganglion cells. Using immunohistochemistry, we found a progressive redistribution of full-length Max from the nucleus to the cytoplasm and dendrites of the ganglion cells following axon damage. Then, the axotomized cells lose all their content of Max, while undergoing nuclear pyknosis and apoptotic cell death. After treatment of retinal explants with either anisomycin or thapsigargin, the rate of nuclear exclusion of Max accompanied the rate of cell death as modulated by either drug. Treatment with a pan-caspase inhibitor abolished both TUNEL staining and immunoreactivity for activated caspase-3, but did not affect the subcellular redistribution of Max immunoreactivity after axotomy. The data show that nuclear exclusion of the transcription factor Max is an early event, which precedes and is independent of the activation of caspases, during apoptotic cell death in the central nervous system. J. Cell. Physiol. 198: 179,187, 2004© 2003 Wiley-Liss, Inc. [source] Evidence that caspase-1 is a negative regulator of AMPA receptor-mediated long-term potentiation at hippocampal synapsesJOURNAL OF NEUROCHEMISTRY, Issue 4 2006Chengbiao Lu Abstract Best known for their pivotal role in a form of programmed cell death called apoptosis, caspases may also function in more subtle physiological processes. Caspases are present in synapses and dendrites of neurons where they can be activated in response to glutamate receptor stimulation and calcium influx. Here we tested the hypothesis that caspase-1 plays a role in modulating long-term potentiation (LTP) at hippocampal synapses. We provide evidence that caspase-1 plays a role in regulating ,-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated calcium influx and synaptic plasticity in the hippocampus. LTP of excitatory postsynaptic potentials at CA1 synapses was significantly enhanced when hippocampal slices were treated with either a pan-caspase inhibitor or a selective inhibitor of caspase-1, but not by an inhibitor of caspase-6. Inhibition of caspase-1 significantly enhanced the AMPA current-mediated component of LTP without affecting the N -methyl- d -aspartate current-mediated component. Calcium responses to AMPA were enhanced in hippocampal neurons treated with a caspase-1 inhibitor suggesting that caspase-1 normally functions to reduce AMPA receptor-mediated calcium influx. These findings suggest that, by selectively reducing AMPA currents and calcium influx, caspase-1 functions as a negative regulator of LTP at hippocampal synapses. [source] Inhibition of Caspases In Vivo Protects the Rat Liver Against Alcohol-Induced Sensitization to Bacterial LipopolysaccharideALCOHOLISM, Issue 6 2001Ion V. Deaciuc Background: The mechanisms of liver sensitization by alcohol to Gram-negative bacterial lipopolysaccharide (LPS) remain elusive. The purpose of this study was two-fold: (1) to test the hypothesis that alcohol-enhanced liver apoptosis may be a sensitizing mechanism for LPS and (2) to further characterize the liver apoptotic response to alcohol. Methods: Rats were fed a high-fat, alcohol-containing liquid diet for 14 weeks, treated with LPS (1.0 mg/kg of body weight, intravenously) or saline, followed by injection of a pan-caspase inhibitor {IDN1965;N -[(1,3-dimethylindole-2-carbonyl)-valinyl]-3-amino-4-oxo-5-fluoropentanoic acid; 10 mg/kg of body weight, intraperitoneally} or vehicle, and killed. The following parameters were assessed: plasma aspartate: 2-oxoglutarate aminotransferase activity (AST); liver histology and terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) response; caspase-3, ,8, and ,9 activity; and mRNA and protein expression for two apoptosis-signaling molecules: Fas receptor and Fas ligand; and three apoptosis adaptors: Bax, Bcl-XL, and Bcl-2. Results: Alcohol-feeding-induced liver steatosis, slightly increased caspases' activity, the number of TUNEL-positive nuclei, and facilitated the LPS necrotic effect without affecting mRNA expression of apoptosis signals and adaptors. LPS induced a significant increase in AST and the number of TUNEL-positive nuclei, both effects being more pronounced in alcohol-treated rats. LPS produced hepatic necrosis only in alcohol-treated rats. LPS effects were associated with up-regulation of mRNA expression for both apoptosis adaptors and signaling molecules. IDN1965 administration 3 hr after LPS injection strongly inhibited caspases' activity, particularly that of caspase-3. IDN1965 also abolished the increase in TUNEL-positive nuclei, reversed the effect of LPS on plasma AST in alcohol-treated rats, and prevented LPS-induced necrosis. Conclusions: (1) Alcohol-enhanced liver apoptosis may not involve regulatory steps at the transcriptional level. LPS-induced liver apoptosis seems to involve transcriptional regulation of several apoptosis adaptors. Therefore, alcohol and LPS may enhance liver apoptosis through different mechanisms. (2) Alcohol-enhanced liver apoptosis precedes and may facilitate the hepatic effects of LPS. LPS superimposed on alcohol further elevates the rate of apoptosis in the liver. This may exceed the phagocytosing capacity of the liver so that all the apoptotic cells are not phagocytosed, but rather die of necrosis. [source] p53 cooperates berberine-induced growth inhibition and apoptosis of non-small cell human lung cancer cells in vitro and tumor xenograft growth in vivoMOLECULAR CARCINOGENESIS, Issue 1 2009Santosh K. Katiyar Abstract Berberine has been shown to have anti-carcinogenic effects. Since p53 is the most commonly mutated tumor suppressor gene, and a lack of functional p53 is associated with an increased risk of cancer development, we examined the effects of berberine on p53-positive and p53-deficient non-small cell human lung cancer cells in vitro and in vivo. Treatment of A549, which express wild-type p53, and H1299, which are p53-deficient, human lung cancer cells with berberine resulted in inhibition of cell proliferation and an increase in apoptotic cell death; however, A549 cells were more sensitive to the berberine-induced cytotoxic effects than H1299 cells. Further, the treatment of A549 cells with pifithrin-,, a specific inhibitor of p53, or transfection of A549 cells with a p53 antisense oligodeoxynucleotide resulted in a reduction in the berberine-induced inhibition of cell proliferation and apoptosis. The berberine-induced apoptosis of both the A549 and H1299 human lung cancer cells was associated with the disruption of mitochondrial membrane potential, reduction in the levels of Bcl-2, Bcl-xl while increase in Bax, Bak, and activation of caspase-3. Treatment of the cells with pan-caspase inhibitor (z-VAD-fmk) or caspase-3 inhibitor (z-DEVD-fmk) inhibited berberine-induced apoptosis, thus suggesting the role of caspase-3. Further, the administration of berberine by oral gavage inhibited the growth of s.c. A549 and H1299 lung tumor xenografts in athymic nude mice, however, the growth of tumor xenograft of H1299 cells was faster than A549 cells in mice and the chemotherapeutic effect of berberine was more pronounced in the p53-positive-A549 tumor xenograft than p53-deficient-H1299 tumor xenograft. © 2008 Wiley-Liss, Inc. [source] Relevance of caspase activity during apoptosis in pubertal rat spermatogenesisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 5 2008Veronica A. Codelia Abstract Caspases are a family of cysteine-proteases, activated upon several different stimuli, which execute apoptosis in many cell death models. Previous work of our group has shown rats have the highest rate of apoptosis during the first wave of spermatogenesis (between 20 and 25 days after birth), as evaluated by TUNEL and caspase activity. However, the hierarchical order of caspase activation and the relevance of each caspase during germ cell apoptosis are not clear. Thus, the goal of this work is to take a pharmacological approach to dissect the apoptosis pathway of caspase activation. Results showed that intratesticular injection of a caspase-8 inhibitor (z-IETD-fmk), or a pan-caspase inhibitor (z-VAD- fmk), significantly decreased the cleavage of p115 and PARP, two endogenous substrates of caspases, in 22-day-old rats. Additionally, these inhibitors promoted a significant reduction in the number of apoptotic germ cells. On the other hand, intratesticular injection of two different inhibitors of the intrinsic pathway (z-LEHD-fmk and minocycline) did not have any effect upon caspase substrates cleavage (p115 and PARP) or the number of apoptotic germ cells. Therefore, we conclude that the extrinsic pathway of apoptosis plays an important role in physiological germ cell apoptosis during the first round of spermatogenesis in the rat. Mol. Reprod. Dev. 75: 881,889, 2008. © 2007 Wiley-Liss, Inc. [source] Fas-mediated upregulation of vascular endothelial growth factor and monocyte chemoattractant protein-1 expression in cultured dermal fibroblasts: Role in the inflammatory responseTHE JOURNAL OF DERMATOLOGY, Issue 2 2007Masao FUJIWARA ABSTRACT The Fas,Fas ligand interaction is the most important pathway in starting apoptosis. In addition, several recent reports have emerged documenting non-apoptotic roles for Fas. However, a non-apoptotic role of Fas in dermal fibroblasts remains unknown. The present study investigated whether Fas stimulation not only promotes apoptosis but also stimulates elements of the inflammatory response such as angiogenesis and macrophage infiltration. Fas stimulation was performed by treating cultured human dermal fibroblasts with an agonistic anti-Fas monoclonal antibody (mAb). Anti-Fas mAb-treated fibroblasts showed a significantly greater increase of caspase-3 and caspase-8 activity compared with control fibroblasts. Addition of the anti-Fas mAb induced DNA fragmentation, as confirmed by the DNA ladder assay. Terminal deoxynucleotidyl transferase-mediated 2,-deoxyuridine 5,-triphosphate nick end labeling (TUNEL) staining showed that treatment with the anti-Fas mAb induced an increase of apoptotic fibroblasts in a time-dependent manner. At both mRNA and protein levels, anti-Fas mAb-treated fibroblasts showed significantly higher expression of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein (MCP)-1 compared with control fibroblasts. A pan-caspase inhibitor (Z-VAD-FMK) significantly inhibited VEGF and MCP-1 expression. After transplantation of fibroblasts into mice with severe combined immunodeficiency, the nodules derived from anti-Fas mAb-treated fibroblasts showed more abundant neovascularization, increased macrophage infiltration, and more apoptotic cells in comparison with nodules derived from control fibroblasts. The results of both in vitro and in vivo studies confirmed significantly higher angiogenic activity and macrophage chemotactic activity of anti-Fas mAb-treated fibroblasts compared with control fibroblasts. [source] Postischemic treatment of neonatal cerebral ischemia should target autophagy,ANNALS OF NEUROLOGY, Issue 3 2009Julien Puyal PhD Objective To evaluate the contributions of autophagic, necrotic, and apoptotic cell death mechanisms after neonatal cerebral ischemia and hence define the most appropriate neuroprotective approach for postischemic therapy. Methods Rats were exposed to transient focal cerebral ischemia on postnatal day 12. Some rats were treated by postischemic administration of pan-caspase or autophagy inhibitors. The ischemic brain tissue was studied histologically, biochemically, and ultrastructurally for autophagic, apoptotic, and necrotic markers. Results Lysosomal and autophagic activities were increased in neurons in the ischemic area from 6 to 24 hours postinjury, as shown by immunohistochemistry against lysosomal-associated membrane protein 1 and cathepsin D, by acid phosphatase histochemistry, by increased expression of autophagosome-specific LC3-II and by punctate LC3 staining. Electron microscopy confirmed the presence of large autolysosomes and putative autophagosomes in neurons. The increases in lysosomal activity and autophagosome formation together demonstrate increased autophagy, which occurred mainly in the border of the lesion, suggesting its involvement in delayed cell death. We also provide evidence for necrosis near the center of the lesion and apoptotic-like cell death in its border, but in nonautophagic cells. Postischemic intracerebroventricular injections of autophagy inhibitor 3-methyladenine strongly reduced the lesion volume (by 46%) even when given >4 hours after the beginning of the ischemia, whereas pan-caspase inhibitors, carbobenzoxy-valyl-alanyl-aspartyl(OMe)-fluoromethylketone and quinoline-val-asp(OMe)-Ch2-O-phenoxy, provided no protection. Interpretation The prominence of autophagic neuronal death in the ischemic penumbra and the neuroprotective efficacy of postischemic autophagy inhibition indicate that autophagy should be a primary target in the treatment of neonatal cerebral ischemia. Ann Neurol 2009 [source] | |||||||||||||