Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.36 (caspase-1)
 6,285 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bcl-2 expression is able to confer drug resistance to chemotherapy-induced programmed cell death. Bax, a partner protein of bcl-2 with extensive aminoacid homology, is a promoter of apoptosis. Apparently the equilibrium of bcl-2 and bax hetero- and homodimers is important for the susceptibility of cells for stimuli inducing apoptosis. In this study we determined the role of bcl-2 to bax expression ratio, bcl-xL and ICE expression level for predicting clinical response to chemotherapy in acute myelold leukemia (AML). Bone marrow samples from 14 patients with AML were examined using an immunophosphatase staining method. Initial bone marrow blast portion was over 80% in all cases. Clinical response was defined by bone marrow aspiration 4 weeks after treatment initiation. There was a significant correlation between bcl-2 to bax expression ratio and clinical response (P < 0.005). No patients with a bcl-2/bax ratio >1.0 achieved complete remission after induction therapy. No significant correlation between bcl-2- and p-glycoprotein-expression was observed in this group. Conversely a high expression of ICE indicated a good clinical response (P < 0.01), whereas expression of bcl-xL had no influence on therapeutic success in this group.
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PMID:Association of bcl-2, bax, bcl-xL and interleukin-1 beta-converting enzyme expression with initial response to chemotherapy in acute myeloid leukemia. 865 95

The disruption of interactions between extracellular matrix and specific cognate integrins triggers apoptosis in epithelial cells, in a process termed "anoikis." To understand anoikis, the connections between epithelial cell integrin signaling and the apoptosis-regulatory proteins are being explored. We report herein that early after detachment from matrix, epithelial cells activate Jun-N-Terminal Kinases (JNKs; alternatively known as Stress-activated Protein Kinases), which are also activated by other apoptotic stimuli. The activity of this pathway was required for anoikis. Another early response to cell suspension was the activation of the ICE-related cysteine protease, ICE/LAP3; this activation and anoikis were suppressed by the ICE-protease inhibitor, crmA. The overexpression of bcl-2 suppressed ICE/LAP3 activation as well. Surprisingly, bcl-2 and crmA attenuated the activation of JNKs following cell suspension, suggesting that the JNK pathway is regulated directly or indirectly by proteolysis. In addition, the blockage of the JNK pathway attenuated the activation of ICE/LAP3, suggesting a positive feedback loop between the ICE and JNK systems. These results indicate the following sequence of information flow in anoikis: integrins-->bcl-2/bax-->(ICE-proteases<-->JNK)-->apopt osis. Cell-cell interactions, which were previously shown to sensitize cells to anoikis, caused bcl-2 mRNA to be downregulated, a permissive event for downstream apoptotic signaling.
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PMID:A role for Jun-N-terminal kinase in anoikis; suppression by bcl-2 and crmA. 894 58

Although numerous sarcolemmal protein defects in muscular dystrophies have been identified, the mechanisms linking these defects and muscle fibre degeneration are not fully characterized. As there is evidence that apoptosis is part of muscle fibre loss in dystrophin-deficient mdx-mice, apoptotic muscle fibre death may also play a role in humans with muscular dystrophies. We investigated in-situ DNA-fragmentation by the TUNEL-method and expression of apoptosis-related proteins immunohistochemically in 14 children suffering from deficiencies of dystrophin, adhalin, and merosin, and found TUNEL-positive chromatin-cleavage of muscle fibre nuclei in about 10% of non-necrotic muscle fibres. DNA-fragmentation also occurred in groups of 'necrotic and regenerating' muscle fibres with labelling of nuclei in myogenic cells and phagocytizing macrophages. These lesions also revealed expression of apoptosis-promoting factors, such as bax and ICE, inducing cleavage of myofilaments, and of the apoptosis-inhibiting proteins bcl-XL and bcl-2 which neutralized high bax levels. Mimicking embryonal myogenesis, chromatin-fragmentation in 'necrotic and regenerating' areas seems to be part of the regulating events in muscle regeneration to eliminate excessive proliferating satellite cells. Nevertheless, macrophages are also affected by apoptosis after successful removal of necrotic fibres. In humans, DNA-fragmentation and expression of apoptosis-related proteins indicate that apoptosis plays a role in muscle degeneration and regeneration in muscular dystrophies.
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PMID:DNA-fragmentation and expression of apoptosis-related proteins in muscular dystrophies. 929 73

Apoptosis, or programmed cell death, is an active process of self-destruction, described a long time ago. However, the understanding of the molecular pathways which regulate programmed cell death is more recent and far from complete. Apoptosis occurs during embryonic and foetal development, and tissue remodeling, and its purpose is to assure homeostasis of cells and tissues. Apoptosis-defining morphological and biochemical changes are now well documented. Many physiological and non-physiological factors have been described as inducers of apoptosis. Several genes affecting various steps in programmed cell death must be expressed to trigger apoptosis. For example, ced-3 and ced-4 in the nematode C. elegans, and ICE, a gene found in mammals. In addition, the existence of genes suppressing apoptosis, like the human bcl-2 gene and a family of related bcl-2 genes was recently described. Several data dealing with these family of anti-apoptotic genes and some of their mechanisms of action are now currently available. It is clear that bcl-2 protects many cell lines from induced apoptosis. Other proteins, like bcl-xL, A1 or mcl-1 have the same anti-apoptotic function, but several molecules of the same family, like bcl-xS, bax-alpha or bak can trigger the opposite effect. It is known that bcl-2 can interact with other proteins. For example, bax, which can exist as a homodimer, is also able to form a heterodimer with bcl-2. A surexpression of bax in several cell lines allows to counteract the effect of bcl-2. R-ras p23 is another example, among others, of a protein interacting with bcl-2, and this results in an interruption of the apoptotic signal transduction pathway when bcl-2 is overexpressed. Some other explanations allowing a more detailed analysis of the molecular mechanisms of apoptosis and anti-apoptosis are discussed in this short review. Many interesting results suggest that bcl-2 is a death repressor molecule functioning in an anti-oxydant pathway, but other recent data seem to claim the contrary. Recently, the demonstration was made that apoptosis may require the activation of several classes of proteases. It seems now that bcl-2 has also a function of protease(s) inhibitor.
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PMID:[Apoptosis and anti-apoptosis genes in the Bcl-2 family]. 929 41

The tumor suppressor p53 has been implicated in apoptosis induction and is mutated in human T-ALL CCRF-CEM cells. To investigate possible consequences of wild-type p53 loss, we reconstituted CEM-C7H2, a subclone of CCRF-CEM, with a temperature-sensitive p53 allele (p53ts). Stably transfected lines expressed high levels of p53ts and shift to the permissive temperature (32 degrees C) caused rapid induction of p53-regulated genes, such as p21(CIP1/WAF1), mdm-2 and bax. This was followed by extensive apoptosis within 24 h to 36 h, supporting the notion that mutational p53 inactivation contributed to the malignant phenotype. p53-dependent apoptosis was preceded by digestion of poly(ADP-ribose) polymerase, a typical target of interleukin-1beta-converting enzyme (ICE)-like proteases/caspases, and was markedly resistant to the ICE/caspase-1 and FLICE/caspase-8 inhibitor acetyl-Tyr-Val-Ala-Asp.chloromethylketone (YVAD), but sensitive to the CPP32/caspase-3 inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp.fluoromethylketone (DEVD) and benzyloxycarbonyl-Val-Ala-Asp.fluoromethylketone (zVAD), a caspase inhibitor with broader specificity. This indicated an essential involvement of caspases, but argued against a significant role of ICE/caspase-1 or FLICE/caspase-8. Actinomycin D or cycloheximide prevented cell death, suggesting that, in this system, p53-induced apoptosis depends upon macromolecule biosynthesis. Introduction of functional p53 into CEM cells enhanced their sensitivity to the DNA-damaging agent doxorubicin, but not to the tubulin-active compound vincristine. Thus, mutational p53 inactivation in ALL might entail relative resistance to DNA-damaging, but not to tubulin-destabilizing, chemotherapy.
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PMID:p53-induced apoptosis in the human T-ALL cell line CCRF-CEM. 939 39

Apoptosis has been described as one of the mechanisms of muscle fiber loss in infantile spinal muscular atrophy. In order to investigate if muscle fiber-apoptosis plays a role in other denervating disorders as well, we studied DNA-fragmentation, a hallmark of apoptosis, by the TUNEL-method and, moreover, the expression patterns of apoptosis-related proteins in 2 patients suffering from ALS and in 6 patients with polyneuropathy. We identified DNA-cleavage in muscle fibers of all these patients. Furthermore, we found strong expression of bax and ICE promoting apoptosis in muscle fibers. However, also strong expression of the anti-apoptotic factor bcl-2 was found. Our findings indicate that defective innervation may prompt muscle fibers to activate an intrinsic "suicide" programme which is promoted by the proapoptotic factors bax and ICE, which seems to induce formation of apoptotic bodies by cleavage of actin. Nevertheless, there are also anti-apoptotic strategies in muscle fibers manifested by expression of the bax-antagonist bcl-2 which is able to neutralize high bax levels.
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PMID:DNA-fragmentation and apoptosis-related proteins of muscle cells in motor neuron disorders. 944 76

In order to characterize cell death mechanisms involved in Alzheimer disease (AD), we quantitated the expression of ced-3 and ced-9 homologs in AD frontal cortex. Positive (ICE, ICErel-II, ICErel-III, Ich-1L, CPP32, mch2, mch3, bcl-xS, bax and bak) and negative (bcl-2, bcl-xL, MCL1 and Ich-1S) regulators of apoptosis were successively examined using a semi-quantitative technique of reverse transcription-polymerase chain reaction (RT-PCR). Total RNA was extracted from postmortem frontal cortex of AD patients (n = 7) and controls (n = 7) matched for age and autolysis time. Baseline levels of message were detected for 3 ced-3 (CPP32, Ich-1 and ICE) and 4 ced-9 homologs (bcl-x, MCL1, bcl-2 and bax) in the frontal cortex. There was an overexpression of the ICEalpha cDNA in AD patients as compared with age-matched controls (P = 0.03). Our results indicate that several ced-3 and ced-9 homologs are expressed in the adult human brain, and suggest that neuronal cell death in AD might involve an aberrant expression of ICEalpha.
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PMID:Expression of ced-3 and ced-9 homologs in Alzheimer's disease cerebral cortex. 957 87

The extracellular microenvironment of tumors differs from that of most normal tissues. Many tumors have relatively acidic extracellular pH, although the intracellular pH of tumor cells remains normal due to the efficient maintenance of a large proton gradient across the membrane. This difference between tumors and normal tissues might be exploited therapeutically by disruption of the mechanisms that regulate intracellular pH, so that tumor cells are killed by intracellular acid-induced injury. To investigate the mechanisms by which intracellular acidification leads to cell death, we have studied the roles of the antiapoptotic gene bcl-2 and its proapoptotic binding partner bax, the stress-activated protein kinases (SAPK/JNK), and the caspase proteases in mediating acid-induced cell death. Whereas the expression of bcl-2 in human bladder cancer MGH-U1 cells had no effect on acid-induced death, overexpression of bax enhanced cell death, consistent with its proapoptotic function. Inhibition of SAPK, through the expression of a dominant negative mutant of its activator, SEK1, protected cells from acid-induced cell death. Caspase activation, as measured by poly(ADP-ribose) polymerase cleavage, was absent after lethal intracellular acidification. Consistent with this observation, inhibition of interleukin 1beta-converting enzyme proteases by the peptide z-Val-Ala-Asp(OMe)-CH2F did not protect against acid-induced cell killing. We conclude that acid-induced cell death depends on bax and on SAPK signaling pathways, but not on the caspase proteases. Therapeutic manipulation of bax and SAPK may enhance acid-induced tumor cell killing.
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PMID:Death of tumor cells after intracellular acidification is dependent on stress-activated protein kinases (SAPK/JNK) pathway activation and cannot be inhibited by Bcl-2 expression or interleukin 1beta-converting enzyme inhibition. 966 94

Mice exposed to 100% O2 die after 3 or 4 d with diffuse alveolar damage and alveolar edema. Extensive cell death is evident by electron microscopy in the alveolar septa, affecting both endothelial and epithelial cells. The damaged cells show features of both apoptosis (condensation and margination of chromatin) and necrosis (disruption of the plasma membrane). The electrophoretic pattern of lung DNA indicates both internucleosomal fragmentation, characteristic of apoptosis, and overall degradation, characteristic of necrosis. Hyperoxia induces a marked increase in RNA or protein levels of p53, bax, bcl-x, and Fas, which are known to be expressed in certain types of apoptosis. However, we did not detect an increased activity of proteases belonging to the apoptosis "executioner" machinery, such as CPP32 (caspase 3), ICE (caspase 1), or cathepsin D. Furthermore, administration of an ICE-like protease inhibitor did not significantly enhance the resistance to oxygen. Additionally, neither p53-deficient mice nor lpr mice (Fas null) manifested an increased resistance to hyperoxia-induced lung damage. These results show that both necrosis and apoptosis contribute to cell death during hyperoxia. Multiple apoptotic pathways seem to be involved in this, and an antiapoptotic strategy does not attenuate alveolar damage.
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PMID:Oxygen toxicity in mouse lung: pathways to cell death. 976 53

The extracellular microenvironment of tumors differs from most normal tissues. Many tumors have relatively acidic extracellular pH (pHe), although the intracellular pH (pHi) of tumor cells remains normal due to efficient maintenance of a large proton gradient across the membrane. This difference between tumors and normal tissues might be exploited therapeutically by disruption of the mechanisms which regulate pHi, so that tumor cells are killed by intracellular acid-induced injury. To investigate the mechanisms by which intracellular acidification leads to cell death, we have studied the roles of the anti-apoptotic gene bcl-2 and its pro-apoptotic binding partner bax, the Stress Activated Protein Kinases (SAPK/JNK), and the caspase proteases in mediating acid-induced cell death. While expression of bcl-2 in human bladder cancer MGH-U1 cells had no effect on acid-induced death, overexpression of bax enhanced cell death, consistent with its pro-apoptotic function. Inhibition of SAPK, through expression of a dominant negative mutant of its activator, SEK1 protected cells from acid-induced cell death. Caspase activation, as measured by poly (ADP-ribose) polymerase cleavage, was absent after lethal intracellular acidification. Consistent with this observation, inhibition of ICE proteases by the peptide z-VAD.fmk did not protect against acid-induced cell killing. We conclude that acid-induced cell death depends on bax and on SAPK signaling pathways but not on the caspase proteases. Therapeutic manipulation of bax and SAPK may enhance acid-induced tumor cell killing.
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PMID:Inhibition of apoptotic signaling pathways in cancer cells as a mechanism of chemotherapy resistance. 977 Jan 20


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