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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)
The interleukin-1 beta (
IL-1 beta
) converting enzyme (
ICE
) processes the inactive
IL-1 beta
precursor to the proinflammatory cytokine. Adherent monocytes from mice harboring a disrupted
ICE
gene (
ICE
-/-) did not export
IL-1 beta
or interleukin-1 alpha (IL-1 alpha) after stimulation with lipopolysaccharide. Export of tumor necrosis factor-alpha and interleukin-6 (IL-6) from these cells was also diminished. Thymocytes from
ICE
-/- mice were sensitive to apoptosis induced by dexamethasone or ionizing radiation, but were resistant to apoptosis induced by Fas antibody. Despite this defect in apoptosis,
ICE
-/- mice proceed normally through development.
...
PMID:Altered cytokine export and apoptosis in mice deficient in interleukin-1 beta converting enzyme. 753 75
The Caenorhabditis elegans death susceptibility gene, ced-3, has a number of homologs in vertebrate species, including interleukin-1 beta (
IL-1 beta
)-converting enzyme (
ICE
), Ich-1long, and CPP32. These genes, which encode a family of related proteases, have been shown to induce apoptosis when transfected into eukaryotic cells. However, it remains to be determined whether these proteases are involved in apoptotic cell death under physiological conditions. The purpose of these studies was to examine the role of
ICE
-related proteases (IRPs) in apoptosis using a physiologically relevant model system, the ovarian follicle. Somatic granulosa cells within ovarian follicles undergo apoptosis during follicular atresia, a process responsible for the depletion of greater than 95% of the follicles established in the postnatal ovary. To accomplish these studies, we cloned partial rat complementary DNAs encoding
ICE
, Ich-1, and CPP32 and used these complementary DNAs to examine the gonadotropin regulation of
ICE
, Ich-1, and CPP32 gene expression in the immature rat ovary. We also examined levels of
ICE
activity in healthy and atretic rat follicles by monitoring the conversion of exogenous pro-
IL-1 beta
to the active cytokine, and then evaluated the actions of recombinant
IL-1 beta
on apoptosis in follicles incubated in vitro. Finally, we tested the requirement for IRP activity in granulosa cell apoptosis and follicular atresia by incubating follicles without and with IRP inhibitors. Northern blot analysis of total RNA samples indicated that gonadotropin-promoted follicular survival was associated with reduced ovarian expression of messenger RNAs encoding Ich-1 and CPP32. In contrast,
ICE
messenger RNA levels were extremely low and were not affected by gonadotropin treatment. We were also unable to detect
ICE
activity in proteins extracted from either healthy or atretic rat follicles, collectively suggesting that
ICE
per se may not function in granulosa cell death. As another approach to determine whether
ICE
is involved in atresia, healthy antral follicles were isolated from ovaries of gonadotropin-primed immature rats and incubated for 24 h in the absence or presence of 100 ng/ml transforming growth factor-alpha (TGF alpha) without and with 100 ng/ml
IL-1 beta
. Granulosa cells within follicles incubated in medium alone exhibited extensive levels of apoptosis, and this onset of apoptosis was prevented by the inclusion of TGF alpha. Addition of
IL-1 beta
did not alter basal levels of apoptosis nor did the cytokine antagonize TGF-alpha-promoted follicle survival, providing additional evidence that
ICE
activity is not required for atresia to occur.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Interleukin-1 beta-converting enzyme-related proteases (IRPs) and mammalian cell death: dissociation of IRP-induced oligonucleosomal endonuclease activity from morphological apoptosis in granulosa cells of the ovarian follicle. 758 40
Interleukin-1 beta (
IL-1 beta
)-converting enzyme (
ICE
) is a novel cysteine protease that cleaves the 31-kD inactive cytoplasmic
IL-1 beta
precursor into active extracellular 17-kD
IL-1 beta
. The
ICE
gene product is a 45-kD proenzyme that requires proteolytic processing to activate
ICE
. Active
ICE
is a heterodimer consisting of equal amounts of p20 and p10 subunits. Generation of active
ICE
is affected by the removal of an 11-kD NH2-terminal precursor domain (p11) and an internal 19-amino acid sequence that separates the 20- and 10-kD subunits. Immuno-electron microscopy was performed on human monocytes with immunoglobulins recognizing the active (p20) or precursor (p11) domains of
ICE
. Elutriated monocytes were stimulated with 50 pM lipopolysaccharide followed by heat-killed Staphylococcus aureus under conditions that induce maximal rates of
IL-1 beta
secretion. Ultrathin cryosections were cut from fixed frozen pellets of these monocytes and were immunogold labeled with either antibody. Active and precursor domain
ICE
epitopes were localized in the cytoplasmic ground substance, but they were not detected within the endoplasmic reticulum, the Golgi apparatus, and secretory granules of activated or inactive monocytes. Importantly, numerous
ICE
p20 epitopes were also observed on the extracellular surfaces of the cell membrane, and were concentrated on the microvilli. Very similar patterns of
ICE
localization were obtained with unstimulated blood monocytes. In contrast,
ICE
p11 epitopes were not detected on the surfaces of these monocytes. Likewise, labeling of fixed ultrathin cryosections of monocytes with a biotinylated irreversible
ICE
inhibitor [Ac-Tyr-Val-Lys(biotin)-Asp-(acyloxy)-methyl-ketone] showed that the compound localized on the outer cell surface as well, and to a lesser extent, within the cytoplasmic ground substance. Furthermore, antipeptide antibodies specific for either the mature or precursor domains of
IL-1 beta
were both localized upon the cell membrane after stimulation of
IL-1 beta
secretion. Lipopolysaccaride-primed monocytes that synthesized, but did not secrete
IL-1 beta
, exhibited only cytoplasmic staining. The data suggests that mature
IL-1 beta
is generated via cleavage of the 31-kD inactive cytoplasmic
IL-1 beta
precursor by
ICE
after association with the plasma membrane during secretion.
...
PMID:The interleukin-1 beta-converting enzyme (ICE) is localized on the external cell surface membranes and in the cytoplasmic ground substance of human monocytes by immuno-electron microscopy. 759 15
In the present study we investigated the effects of IL-1 antagonism on the autonomous growth of cells in acute myeloblastic leukemia (AML). To examine the role of pro-IL-1 processing, antisense technology was employed with 16-mer phosphorothioate oligodeoxynucleotide directed against human
IL-1 beta
converting enzyme (ICR) in 7 randomly selected AML cases. The addition of 10-75 microM of antisense oligonucleotide (but not of control oligonucleotide) significantly inhibited spontaneous proliferation of bone marrow- (BM) and peripheral blood- (PB) derived low density leukemic cells in a dose-dependent way. Similarly, spontaneous as well as induced CFU-AML colony formation was inhibited by human
ICE
antisense oligonucleotide with sample-to-sample variability. In separate experiments, in order to examine the effects of blockade of endogenously produced IL-1 to IL-1 receptors, the functional activity of human recombinant IL-1 receptor antagonist (IL-1ra) was tested. Continuous exposure to high concentrations of IL-1ra (up to 100 micrograms/ml) produced dose-dependent inhibition of spontaneous proliferation of the BM-derived blast cells from 9 of the 14 patients and of the PB-derived cells from 10 of the 14 patients. However, in some of these patients, the lower IL-1ra doses (down to 100 ng/ml) induced potentiation of spontaneous proliferation, suggesting a novel regulatory pathway for IL-1 receptor engagement. Similar results were obtained on CFU-AML colony formation, showing inhibition at higher IL-1ra doses, but in a few AML cases stimulatory effect at lower IL-1ra doses.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Modulation of acute myeloblastic leukemia (AML) cell proliferation and blast colony formation by antisense oligomer for IL-1 beta converting enzyme (ICE) and IL-1 receptor antagonist (IL-1ra). 762 64
We report here that the activation of the interleukin 1 beta (
IL-1 beta
)-converting enzyme (
ICE
) family is likely to be one of the crucial events of tumor necrosis factor (TNF) cytotoxicity. The cowpox virus CrmA protein, a member of the serpin superfamily, inhibits the enzymatic activity of
ICE
and
ICE
-mediated apoptosis. HeLa cells overexpressing crmA are resistant to apoptosis induced by Ice but not by Ich-1, another member of the Ice/ced-3 family of genes. We found that the CrmA-expressing HeLa cells are resistant to TNF-alpha/cycloheximide (CHX)-induced apoptosis. Induction of apoptosis in HeLa cells by TNF-alpha/CHX is associated with secretion of mature
IL-1 beta
, suggesting that an
IL-1 beta
-processing enzyme, most likely
ICE
itself, is activated by TNF-alpha/CHX stimulation. These results suggest that one or more members of the
ICE
family sensitive to CrmA inhibition are activated and play a critical role in apoptosis induced by TNF.
...
PMID:Tumor necrosis factor-induced apoptosis is mediated by a CrmA-sensitive cell death pathway. 766 87
Apoptosis is critically dependent on the presence of the ced-3 gene in Caenorhabditis elegans, which encodes a protein homologous to the mammalian interleukin (IL)-1 beta-converting enzyme (
ICE
). Overexpression of
ICE
or ced-3 promotes apoptosis. Cytotoxic T lymphocyte-mediated rapid apoptosis is induced by the proteases granzyme A and B.
ICE
and granzyme B share the rare substrate site of aspartic acid, after which amino acid cleavage of precursor
IL-1 beta
(pIL-1 beta) occurs. Here we show that granzyme A, but not granzyme B, converts pIL-1 beta to its 17-kD mature form. Major cleavage occurs at Arg120, four amino acids downstream of the authentic processing site, Asp116.
IL-1 beta
generated by granzyme A is biologically active. When pIL-1 beta processing is monitored in lipopolysaccharide-activated macrophage target cells attacked by cytotoxic T lymphocytes, intracellular conversion precedes lysis. Prior granzyme inactivation blocks this processing. We conclude that the apoptosis-inducing granzyme A and
ICE
share at least one downstream target substrate, i.e., pIL-1 beta. This suggests that lymphocytes, by means of their own converting enzyme, could initiate a local inflammatory response independent of the presence of
ICE
.
...
PMID:Granzyme A is an interleukin 1 beta-converting enzyme. 772 67
Interleukin-1 beta (
IL-1 beta
) converting enzyme (
ICE
) processes the precursor of the cytokine
IL-1 beta
to a mature, biologically active form in monocytes and macrophages. To further understand the role of
ICE
in regulating
IL-1 beta
-mediated biological functions, we have isolated several genomic clones encoding the full-length murine
ICE
gene. Southern blot comparison of murine genomic DNA and the clones indicates that
ICE
is a compact, single-copy gene 8616 bp in size. We sequenced the entire gene as well as 1.0-kb segment upstream of the coding region and determined that the gene consists of 10 exons whose organization parallels the functional organization of the
ICE
proenzyme in that the prodomain and p20 and p10 subunits of
ICE
are encoded by three clusters of exons. Two initiation sites, 37 and 32 nucleotides upstream of the initiator methionine, were identified by primer extension analysis. The 5' region of the
ICE
gene lacks a TATA box, a CAAT box, and SP1 sites. However, the presence of a completely conserved 14-bp sequence spanning the transcription initiation site of both the murine and the human
ICE
genes suggests that this sequence plays a role in transcription.
...
PMID:The structure and complete nucleotide sequence of the murine gene encoding interleukin-1 beta converting enzyme (ICE). 803 21
Interleukin-1 beta (
IL-1 beta
) converting enzyme (
ICE
) is a cysteine protease that specifically cleaves precursor
IL-1 beta
to its biologically active form. Recent studies have also implicated
ICE
in the induction of apoptosis in vertebrate cells. Because IL-1 plays a major role in acute myelogenous leukemia (AML) blast proliferation, we sought to investigate the effect of
ICE
inhibition on AML progenitors. To do this, we used bocaspartyl (benzyl) chloromethylketone (BACMK) an inhibitor designed to penetrate cells and bind covalently to the active site of
ICE
. Our preliminary experiments showed that incubation of activated peripheral blood cells with 2.5 mumol/L of BAMCK downregulated production of mature
IL-1 beta
but had no effect on tumor necrosis factor-alpha. To test the effects of the inhibitor on AML cells, we first used the OCI/AML3 cell line. We found that these cells produce
IL-1 beta
and bind the biotinylated cytokine and that IL-1 inhibitors, such as IL-1 neutralizing antibodies, IL-1 receptor antagonist, and soluble IL-1 receptors, specifically inhibit OCI/AML3 proliferation, indicating that
IL-1 beta
is an autocrine growth factor for OCI/AML3 cells. The
ICE
inhibitor suppressed OCI/AML3 growth in a dose-dependent manner (at 0.4 to 4 mumol/L) and downregulated mature
IL-1 beta
production, as assessed by Western immunoblotting. Similar results were obtained with marrow aspirates from 16 AML patients. The
ICE
inhibitor suppressed proliferation of AML precursors (by up to 78%; mean, 44%) in a dose-dependent fashion at concentrations ranging from 0.4 to 5 mumol/L but not proliferation of normal marrow progenitors; the suppressive effect was reversed by
IL-1 beta
. Furthermore, incubation of AML cells with 4 mumol/L BAMCK downregulated the production of mature
IL-1 beta
, suggesting that the growth-inhibitory effect is mediated through suppression of the biologically active cytokine. Our data indicate that inhibition of
ICE
suppresses AML blast proliferation and suggest that
ICE
inhibitors may have a role in future therapies for AML.
...
PMID:Effect of interleukin-1 beta converting enzyme inhibitor on acute myelogenous leukemia progenitor proliferation. 854 50
Interleukin (IL)-1 beta-converting enzyme (
ICE
) cleaves the biologically inactive precursor form of
IL-1 beta
into mature, bioactive
IL-1 beta
. Because of the potent effects of IL-1 in blood vessels, we conducted an in situ hybridization study to determine whether
ICE
mRNA is constitutively expressed in adult rat brain vasculature. Using in situ hybridization histochemistry, we were able to demonstrate that mRNA in blood vessels scattered throughout the brain. In a second set experiments, we found that the genes encoding not only
ICE
, but also IL-1 alpha,
IL-1 beta
, IL-1 receptor antagonist (IL-1ra), and the IL-1 type I receptor are expressed in brain vasculature. To our knowledge this is the first report documenting the expression of the genes encoding all of the functional elements of the IL-1 system in the same tissue. Our findings have three pathophysiological implications. First, they indicate a possible site where peripheral IL-1 may act in the brain. The vascular IL-1 system stimulates the production of nitric oxide and prostanoids, which could act as mediators of the effects of peripheral IL-1 in the central nervous system. Additionally, vascular IL-1 is known to activate adhesion molecules; our data that the genes encoding the IL-1 system are expressed in brain vasculature further support the concept that IL-1 is implicated in the pathophysiology of atherosclerosis and stroke. Finally, in the context of previous studies documenting that IL-1ra inhibits the effects of IL-1 on endothelial cells, our findings of endogenous IL-1ra mRNA in brain vasculature indicate that IL-1ra might be an endogenous vascular protective agent.
...
PMID:Localization of interleukin-1 beta converting enzyme mRNA in rat brain vasculature: evidence that the genes encoding the interleukin-1 system are constitutively expressed in brain blood vessels. Pathophysiological implications. 864 63
We have generated a series of monoclonal antibodies (mAb) using recombinant interleukin (IL)-1 beta-converting enzyme (
ICE
) p20 and p10 subunits as immunogens. The mAb have been selected for further study based on their reactivity with
ICE
in transfected COS cells and their lack of cross-reactivity with TX, the closest
ICE
homolog known to date. Two anti-p20 and one anti-p10 mAb have been used to study
ICE
expression by Western blotting and immunodetection. In
ICE
-transfected COS cells, the mAb recognize the p45
ICE
precursor and the maturation products (p20 or p10 subunits) for which they are specific. In monocytes and cell lines expressing
ICE
, only precursor forms are detected and intracellular immunostaining followed by confocal microscopy shows that they are located in the cytoplasm. Quantification experiments show that THP1 cells express approximately 67,000 molecules of
ICE
precursor per cell, with an estimated precursor to mature ratio of at least 100. In these cells as well as in monocytes, lipopolysaccharide stimulation did not change the pattern of
ICE
expression, although efficient secretion of mature
IL-1 beta
was measured. However, upon cell disruption, precursor maturation was observed. Our results, therefore, show that
ICE
is present in cells as a large pool of intracytoplasmic precursor, and that very limited amounts of mature
ICE
protein are present, but nevertheless sufficient to allow efficient
IL-1 beta
cleavage. Altogether, these observations suggest that post-translational maturation of the precursor protein could represent a specific step in the regulation of
ICE
enzymatic activity.
...
PMID:Use of monoclonal antibodies to study interleukin-1 beta-converting enzyme expression: only precursor forms are detected in interleukin-1 beta-secreting cells. 864 64
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