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)

While there has been extensive work describing the timing, location and probable signals responsible for regulating programmed cell death (PCD) in the nervous system, relatively little is known about the molecular mechanisms that mediate this process. Several investigators have demonstrated that PCD in general, and neuronal PCD in particular, can be inhibited by drugs that arrest RNA or protein synthesis. These data have been interpreted as suggesting that de novo gene expression is required for cells to commit suicide. The general picture emerging from a number of experimental systems is that a variety of proteins can mediate the coupling of extracellular signals to a resident cell-death program. In this model, some of the components required for death are more or less constitutively present in the cell and await lineage-specific signals for their activation. A recent flood of papers has presented convincing evidence that the resident program for apoptosis in numerous cell types works via a series of essential proteases belonging to the CED-3/ICE family.
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PMID:Cold thoughts of death: the role of ICE proteases in neuronal cell death. 896 85

Since mammalian cardiac myocytes essentially rely on aerobic energy metabolism, it has been assumed that cardiocytes die in a catastrophic breakdown of cellular homeostasis (i.e. necrosis), if oxygen supply remains below a critical limit. Recent observations, however, indicate that a process of gene-directed cellular suicide (i.e. apoptosis) is activated in terminally differentiated cardiocytes of the adult mammalian heart by ischemia and reperfusion, and by cardiac overload as well. Apoptosis or programmed cell death is an actively regulated process of cellular self destruction, which requires energy and de novo gene expression, and which is directed by an inborn genetic program. The final result of this program is the fragmentation of nuclear DNA into typical 'nucleosomal ladders', while the functional integrity of the cell membrane and of other cellular organelles is still maintained. The critical step in this regulated apoptotic DNA fragmentation is the proteolytic inactivation of poly-[ADP-ribose]-polymerase (PARP) by a group of cysteine proteases with some structural homologies to interleukin-1 beta-converting enzyme (ICE-related proteases [IRPs] such as apopain, yama and others). PARP catalyzes the ADP-ribosylation of nuclear proteins at the sites of spontaneous DNA strand breaks and thereby facilitates the repair of this DNA damage. IRP-mediated destruction of PARP, the 'supervisor of the genome', can be induced by activation of membrane receptors (e.g. FAS or APOI) and other signals, and is inhibited by activation of 'anti-death genes' (e.g. bcl-2). Overload-triggered myocyte apoptosis appears to contribute to the transition to cardiac failure, which can be prevented by therapeutic hemodynamic unloading. In myocardial ischemia, the activation of the apoptotic program in cardiocytes does not exclude their final destiny to catastrophic necrosis with release of cytosolic enzymes, but might be considered as an adaptive process in hypoperfused ventricular zones, sacrificing some jeopardized myocytes to regulated apoptosis, which may be less arrhythmogenic than necrosis with the primary disturbance of membrane function.
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PMID:Apoptosis in the heart: when and why? 897 66

Apoptosis, a form of cellular suicide, involves the activation of CED-3-related cysteine proteases (caspases). The regulation of caspases by apoptotic signals and the precise mechanism by which they kill the cell remain unknown. In Drosophila, different death-inducing stimuli induce the expression of the apoptotic activator reaper. Cell killing by reaper and two genetically linked apoptotic activators, hid and grim, requires caspase activity. A Drosophila caspase, named Drosophila caspase-1 (DCP-1), was identified and found to be structurally and biochemically similar to Caenorhabditis elegans CED-3. Loss of zygotic DCP-1 function in Drosophila caused larval lethality and melanotic tumors, showing that this gene is essential for normal development.
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PMID:DCP-1, a Drosophila cell death protease essential for development. 899 99

Recent studies indicate that polymicrobial sepsis can markedly increase inducible macrophage Ao (nonnecrotic cellular suicide) and that this is associated with decreased M phi function. In vitro studies suggest that M phi Ao can be induced by IL-1 beta via interleukin-1 beta-converting enzyme (ICE, a cysteine protease), prostanoids, or reactive oxygen/nitrogen. However, the mechanism(s) underlying this process in septic M phi remains unknown. To determine this, male C3H/HeN mice were subjected to sepsis (cecal ligation and puncture, CLP) or sham-operation. Twenty-four hours thereafter, M phi were isolated from the peritoneum (PM phi) and liver (LM phi). Macrophage monolayers were treated with LPS (10 micrograms/ml) alone (Cont) or in the presence of iodoacetamide (Iodo, 5 mM), N-methylmalamide (meth, 5 mM), ibuprophen (Ibu, 40 micrograms/ml), N-methyl-L-arginine (LNMA, 0.4 mM), or superoxide dismutase (SOD, 60,000 U/ml) for 24 hr. The extent of Ao was determined using an enzyme-linked immunosorbent cell-death assay, which detects the presence of cytoplasmic oligonucleosomes measured as optical density. The results indicate that both PM phi and LM phi from septic animals exhibit increased Ao over cells from sham animals. However, only the nonspecific cysteine protease inhibitors (Iodo and meth) and the NO inhibitor LNMA blocked septic mouse M phi Ao. Furthermore, only PM phi from CLP mice treated with Iodo, but not LNMA or IBU, showed an improved capacity to release IL-6. We conclude that increased M phi Ao seen during sepsis appears to be mediated by both ICE-like cysteine protease activation and NO release but the level/mechanism of action of these inhibitors differs.
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PMID:Inducible macrophage apoptosis following sepsis is mediated by cysteine protease activation and nitric oxide release. 924 58

Apoptosis is a morphologically distinct form of programmed cellular death that plays a central role during embryogenesis, tissue homeostasis, and to remove not necessary or potentially dangerous cells. Moreover, disregulation of genes mediating or modulating apoptosis contributes to the pathogenesis of a number of human diseases, including cancer, autoimmune diseases, neurodegenerative disorders, viral infections and acquired immunodeficiency syndrome. A number of genes and molecules promoting or protective against cell death is at present-day known and an important information about the external and internal signals involved in stimulation and suppression of apoptosis is also emerging. In the intracellular pathway of the death deregulation of [Ca2+](i) plays a pivotal role. Increased ionized intracellular calcium stimulates both the activation of enzymes (protein kinases, endonucleases, proteases and phospholipases) and plasma membrane K+ channels. This calcium-mediated activation leads to morphostructural changes, such as cell shrinkage, cytoplasmatic blebbing, nuclear chromatin condensation and DNA degradation into oligonucleosomal fragments. At least some genes of the cell death pathway have been conserved throughout animal evolution; ced-3 e ced-9 that regulate the initiation of cellular suicide in the nematode Caenorhabditis elegans are homologous to genes that in mammalian cells are thought to play a similar role (interleukin-1 beta converting enzyme [ICE] family, Bcl-2). It is possible to suppose that these regulators could constitute a target for treatment of disorders related with disregulation of apoptosis.
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PMID:[Genes, molecules, and mechanisms regulating programmed cell death]. 973 54

Multicellular organisms can employ a number of defences to combat viral replication, the most dramatic being implementation of a cell autonomous apoptotic process. The overall cost to the viability of an organism of losing infected cells by apoptosis may be small if the dying cells can be substituted. In contrast, suicide of irreplaceable cells such as highly specialised neurons may have a more dramatic, even fatal consequence. Previous in vitro approaches to understanding whether neurotropic viruses cause neurons to apoptose have utilised transformed cell lines. These are not in the appropriate state of differentiation to provide an accurate indication of events in vivo. We have chosen to characterise the ability of a model CNS disease-causing virus, Semliki Forest virus (SFV), to infect and trigger apoptosis in primary cultures of nerve growth factor (NGF)-dependent sensory neurons. These cells are known to die when deprived of NGF and constitute a useful indicator of apoptosis. We observe that infection causes cell death which bears the morphological hallmarks of apoptosis, this occurs even in the present of survival promoting NGF and is concomitant with new virus production. Using the TUNEL (transferase dUTP nick end labelling) technique we show that SFV-induced apoptosis involves DNA fragmentation and requires caspase (CED-3/ICE cysteine protease) activation, as does apoptosis induced by NGF-deprivation. Extensive areas of apoptosis, as defined using a combination of ultrastructural analysis and TUNEL occur in infected neonatal mouse brains. The novel evidence that infection of primary neurons with SFV induces apoptosis with activation of one or more caspases defines a system for the further anlaysis of apoptosis regulation in physiologically relevant neurons.
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PMID:Virus infection induces neuronal apoptosis: A comparison with trophic factor withdrawal. 1020 Apr 45

Caspases are a large family of evolutionarily conserved proteases found from Caenorhabditis elegans to humans. Although the first caspase was identified as a processing enzyme for interleukin-1beta, genetic and biochemical data have converged to reveal that many caspases are key mediators of apoptosis, the intrinsic cell suicide program essential for development and tissue homeostasis. Each caspase is a cysteine aspartase; it employs a nucleophilic cysteine in its active site to cleave aspartic acid peptide bonds within proteins. Caspases are synthesized as inactive precursors termed procaspases; proteolytic processing of procaspase generates the tetrameric active caspase enzyme, composed of two repeating heterotypic subunits. Based on kinetic data, substrate specificity, and procaspase structure, caspases have been conceptually divided into initiators and effectors. Initiator caspases activate effector caspases in response to specific cell death signals, and effector caspases cleave various cellular proteins to trigger apoptosis. Adapter protein-mediated oligomerization of procaspases is now recognized as a universal mechanism of initiator caspase activation and underlies the control of both cell surface death receptor and mitochondrial cytochrome c-Apaf-1 apoptosis pathways. Caspase substrates have bene identified that induce each of the classic features of apoptosis, including membrane blebbing, cell body shrinkage, and DNA fragmentation. Mice deficient for caspase genes have highlighted tissue- and signal-specific pathways for apoptosis and demonstrated an independent function for caspase-1 and -11 in cytokine processing. Dysregulation of caspases features prominently in many human diseases, including cancer, autoimmunity, and neurodegenerative disorders, and increasing evidence shows that altering caspase activity can confer therapeutic benefits.
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PMID:Proteases for cell suicide: functions and regulation of caspases. 1110 20

Apoptosis is a cell suicide program characterized by distinct morphological (cell shrinkage, membrane blebbing, pyknosis, chromatin margination, denser cytoplasmic images) and biochemical (e.g., DNA fragmentation into distinct ladders; degradation of apoptotic markers such as PARP and nuclear lamins) features. It is involved in multiple physiological processes examplified by involution of mammary tissues, embryonic development, homeostatic maintenance of tissues and organs, and maturation of the immune system, as well as in many pathological conditions represented by neurologic degeneration (Alzeimer's disease), autoimmune and inflammatory diseases, etiology of atherosclerosis, AIDS, and oncogenesis and tumor progression. Numerous molecular entities have been shown to regulate the apoptotic process. This review provides a concise summary of the recent data on the role of oncogenes/tumor suppressor genes, cytokines and growth factors/growth factor receptors, intracellular signal transducers, cell cycle regulators, reactive oxygen species or other free radicals, extracellular matrix regulators/cell adhesion molecules, and specific endonucleases and cytoplasmic proteases (the ICE family proteins) in regulating cell survival and apoptosis. Elucidation of the molecular mechanisms regulating apoptosis bears tremendous impact on enhancing our understanding of many diseases inflicting the human beings and undoubtedly brings us hope for the cure of these diseases.
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PMID:Apoptosis: A Current Molecular Analysis. 1117 95

In patients with localized prostate cancer, radical prostatectomy and radiation therapy, although effective in controlling localized disease, are often associated with significant side effects attributable to injury of adjacent tissues. Moreover, patients with metastatic disease eventually fail systemic hormonal or chemotherapy because of the development of progressive, refractory disease. In this study, we evaluated the safety and efficacy of a novel suicide gene therapy that could potentially spare normal tissue while bypassing molecular mechanisms of apoptosis resistance by using chemically inducible effector caspases to trigger apoptosis in prostate cancer cells. Initially, we compared the ability of a panel of inducible Fas signaling intermediates to kill human and murine prostate cancer cell lines. On the basis of the superior killing by downstream caspase-1 and caspase-3, replication-deficient adenoviral vectors expressing conditional caspase-1 (Ad-G/iCasp1) or caspase-3 (Ad-G/iCasp3), regulated by nontoxic, lipid-permeable, chemical inducers of dimerization (CID), were constructed. Upon vector transduction followed by CID administration, aggregation and activation of these recombinant caspases occur, leading to rapid apoptosis. In vitro, both human (LNCaP and PC-3) and murine (TRAMP-C2 and TRAMP-C2G) prostate cancer cell lines were efficiently transduced and killed in a CID-dependent fashion. In vivo, direct injection of Ad-G/iCasp1 into s.c. TRAMP-C2 tumors caused focal but extensive apoptosis without evidence for a bystander effect at the maximal viral dose (i.e., 2.5 x 10(10) viral particles/25 microl) in host animals that also received CID compared with control animals. Treatment with Ad-G/iCasp1 plus CID resulted in a transient, yet significant, reduction both in tumor growth and volume compared with tumors treated with vector but not CID (P < 0.035) or vector-diluent plus CID (P < 0.022), both of which grew more rapidly. These results demonstrate that CID-regulated, caspase-based suicide gene therapy is safe and can inhibit the growth of experimental prostate cancer in vitro and in vivo through potent induction of apoptosis, providing a rationale for further development.
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PMID:Adenovirus-mediated transfer of inducible caspases: a novel "death switch" gene therapeutic approach to prostate cancer. 1128 32

Visna-Maedi virus (VMV), an ungulate lentivirus, causes a natural infection in sheep. In vitro, VMV infection and replication lead to strong cytopathic effects with subsequent death of host cells. We investigated, in vitro, the relative contribution of apoptosis or programmed cell death (PCD) to cell killing during acute infection with VMV, by employing diverse strategies to detect its common end-stage alterations. We demonstrated that VMV-infection in sheep choroid plexus cells (SCPC), is associated with apoptosis, characterized by morphological changes such as condensation of chromatin and the appearence of apoptotic bodies. DNA fragmentation was documented by TUNEL assay. Although the mechanism by which VMV activates this cell suicide program is not known, we examined the activation of caspases, the family of death-inducing proteases that resulted in cleavage of several cellular substrates. To study the role of caspases in VMV-induced apoptosis, we focused on several protease targets: procaspase-3 and procaspase-1. During VMV-infection, SCPC display active caspase-3 and no caspase-1 activity. In conclusion, our results suggest that VMV infection, in vitro, induces cell death of SCPC by a mechanism that can be characterized by many of the properties most closely associated with apoptotic cell death.
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PMID:Visna virus-induced cytopathic effect in vitro is caused by apoptosis. 1202 66


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