Inhibition of ICE slows ALS in mice.
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Amyotrophic Lateral Sclerosis↗
Biomedical subjects
J Yuan
Publications and source records attributed to J Yuan.
Characterization of the avian Ich-1 cDNA and expression of Ich-1L mRNA in the hen ovary.
We have sequenced the chicken interleukin-1beta-converting enzyme (ICE) and ced-3 homolog (Ich-1) cDNA, and evaluated Ich-1 mRNA expression in the hen ovary during follicle development. While two alternatively spliced forms of Ich-1, Ich-1L and Ich-1S, were amplified by PCR from an embryonic chicken cDNA library, only the Ich-1L form was found to be expressed in adult ovarian granulosa and theca tissues. The deduced amino acid (aa) sequence of ICH-1L is 70.8% identical to human ICH-1L and contains the conserved QACRG peptide active catalytic sequence characteristic of many ICE-related family of cysteine proteases.
Amino Acid Sequence↗
Hrp pilus: an hrp-dependent bacterial surface appendage produced by Pseudomonas syringae pv. tomato DC3000.
Hypersensitive response and pathogenicity (hrp) genes control the ability of major groups of plant pathogenic bacteria to elicit the hypersensitive response (HR) in resistant plants and to cause disease in susceptible plants. A number of Hrp proteins share significant similarities with components of the type III secretion apparatus and flagellar assembly apparatus in animal pathogenic bacteria. Here we report that Pseudomonas syringae pv. tomato strain DC3000 (race 0) produces a filamentous surface appendage (Hrp pilus) of 6-8 nm in diameter in a solid minimal medium that induces hrp genes. Formation of the Hrp pilus is dependent on at least two hrp genes, hrpS and hrpH (recently renamed hrcC), which are involved in gene regulation and protein secretion, respectively. Our finding of the Hrp pilus, together with recent reports of Salmonella typhimurium surface appendages that are involved in bacterial invasion into the animal cell and of the Agrobacterium tumefaciens virB-dependent pilus that is involved in the transfer of T-DNA into plant cells, suggests that surface appendage formation is a common feature of animal and plant pathogenic bacteria in the infection of eukaryotic cells. Furthermore, we have identified HrpA as a major structural protein of the Hrp pilus. Finally, we show that a nonpolar hrpA mutant of P. syringae pv. tomato DC3000 is unable to form the Hrp pilus or to cause either an HR or disease in plants.
Bacterial Proteins↗
Determination of isatin in urine and plasma by high-performance liquid chromatography.
A method for the detection and determination of isatin (indole-2,3-dione) in urine and plasma by high-performance liquid chromatography has been developed. It consists of a two-step purification using two different columns with UV detection. With this method, we have reconfirmed that isatin is present in human urine. We have also demonstrated that isatin is present in human plasma and that the isatin levels in spot urine samples reflect the plasma isatin levels. In the present report we describe a rapid and sensitive means of determining urine and plasma isatin for laboratories equipped with a high-performance liquid chromatography system.
Adult↗
Systematic mutational analysis of the cation-independent mannose 6-phosphate/insulin-like growth factor II receptor cytoplasmic domain. An acidic cluster containing a key aspartate is important for function in lysosomal enzyme sorting.
We have used systematic mutational analysis to identify signals in the 166-residue murine cation-independent mannose 6-phosphate/insulin-like growth factor II receptor cytoplasmic domain required for efficient sorting of lysosomal enzymes. Alanine cluster mutagenesis on all conserved residues apart from the endocytosis signal demonstrates that the major sorting determinant is a conserved casein kinase II site followed by a dileucine motif (157DDSDEDLL164). Small deletions or additions outside this region have severe to mild effects, indicating that context is important. Single residue mutagenesis indicates that cycles of serine phosphorylation/dephosphorylation are not obligatory for sorting. In addition, the two leucine residues and four of the five negatively charged residues can readily tolerate conservative substitutions. In contrast, aspartate 160 could not tolerate isoelectric or isosteric substitutions, implicating it as a critical component of the sorting signal.
Amino Acid Sequence↗
Suppression of interleukin-1beta converting enzyme (ICE)-induced apoptosis by SV40 large T antigen.
The Interleukin-1beta converting enzyme (ICE) family of proteins, homologs of the C elegans cell death gene product CED-3, play important roles in controlling vertebrate programmed cell death. Because inhibition of apoptosis may be an essential step in tumorigenesis, we investigated the interaction of the simian virus 40 large T antigen (T ag) with the ICE family. COS-1 cells which were transformed by the simian virus 40 do not die when transfected with expression constructs of Ice or Ich-1(L). We found that expression of T ag alone significantly prevents the ICE-induced apoptosis. p53, but not pRb or p107, antagonizes the effect of T ag on the suppression of ICE-induced cell death, but not on ICH-1(L)-mediated cell death. Thus, wild type p53 may potentiate ICE-induced apoptosis. Expression of a temperature sensitive mutant p53Val(135) sensitizes COS-1 cells to apoptosis induced by ICE at permissive but not at non-permissive temperature. While induction of bax, p21(WAF1/CIP), or cyclin D1 gene expression is observed in the COS-1 p53Val(135) cells at the permissive temperature, overexpression of bax, but not p21(WAF1/CIP) or cyclin D1, potentiates ICE-induced COS-1 cell death. Taken together, these results suggest that T ag may modulate the cells' susceptibility to death by suppressing activity of the ICE family through inhibiting p53.
Animals↗
Inhibition of interleukin 1beta converting enzyme family proteases reduces ischemic and excitotoxic neuronal damage.
The interleukin 1beta converting enzyme (ICE) family plays a pivotal role in programmed cell death and has been implicated in stroke and neurodegenerative diseases. During reperfusion after filamentous middle cerebral artery occlusion, ICE-like cleavage products and tissue immunoreactive interleukin 1beta (IL-1beta) levels increased in ischemic mouse brain. Ischemic injury decreased after intracerebroventricular injections of ICE-like protease inhibitors, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD.FMK), acetyl-Tyr-Val-Ala-Asp-chloromethylketone, or a relatively selective inhibitor of CPP32-like caspases, N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone, but not a cathepsin B inhibitor, N-benzyloxycarbonyl-Phe-Ala-fluoromethylketone. z-VAD.FMK decreased ICE-like cleavage products and tissue immunoreactive IL-1beta levels in ischemic mouse brain and reduced tissue damage when administered to rats as well. Only z-VAD.FMK and acetyl-Tyr-Val-Ala-Asp-chloromethylketone reduced brain swelling, and N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone did not attenuate the ischemia-induced increase in tissue IL-1beta levels. The three cysteine protease inhibitors significantly improved behavioral deficits, thereby showing that functional recovery of ischemic neuronal tissue can follow blockade of enzymes associated with apoptotic cell death. Finally, we examined the effect of z-VAD.FMK on excitotoxicity and found that it protected against alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate-induced or to a lesser extent N-methyl-D-aspartate-induced excitotoxic brain damage. Thus, ICE-like and CPP32-like caspases contribute to mechanisms of cell death in ischemic and excitotoxic brain injury and provide therapeutic targets for stroke and neurodegenerative brain damage.
Animals↗
Expression of a dominant negative mutant of interleukin-1 beta converting enzyme in transgenic mice prevents neuronal cell death induced by trophic factor withdrawal and ischemic brain injury.
To explore the role of the interleukin (IL)-1 beta converting enzyme (ICE) in neuronal apoptosis, we designed a mutant ICE gene (C285G) that acts as a dominant negative ICE inhibitor. Microinjection of the mutant ICE gene into embryonal chicken dorsal root ganglial neurons inhibits trophic factor withdrawal-induced apoptosis. Transgenic mice expressing the fused mutant ICE-lacZ gene under the control of the neuron specific enolase promoter appeared neurologically normal. These mice are deficient in processing pro-IL-1 beta, indicating that mutant ICEC285G blocks ICE function. Dorsal root ganglial neurons isolated from transgenic mice were resistant to trophic factor withdrawal-induced apoptosis. In addition, the neurons isolated from newborn ICE knockout mice are similarly resistant to trophic factor withdrawal-induced apoptosis. After permanent focal ischemia by middle cerebral artery occlusion, the mutant ICEC285G transgenic mice show significantly reduced brain injury as well as less behavioral deficits when compared to the wild-type controls. Since ICE is the only enzyme with IL-1 beta convertase activity in mice, our data indicates that the mutant ICEC285G inhibits ICE, and hence mature IL-1 beta production, and through this mechanism, at least in part, inhibits apoptosis. Our data suggest that genetic manipulation using ICE family dominant negative inhibitors can ameliorate the extent of ischemia-induced brain injury and preserve neurological function.
Animals↗
2-Phenyl-4(5)-[[4-(pyrimidin-2-yl)piperazin-1-yl]methyl]imidazole. A highly selective antagonist at cloned human D4 receptors.
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Antipsychotic Agents↗
Small pool expression screening: identification of genes involved in cell cycle control, apoptosis, and early development.
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Animals↗
Synthesis of a new tetradentate beta-diketonate-europium chelate and its application for time-resolved fluorimetry of albumin.
A new tetradentate beta-diketone chelator, 1,10-bis(8'-chlorosulfo-dibenzothiophene-2'-yl)-4,4,5,5,6,6,7,7, -octafluorodecane-1,3,8,10-tetraone (BCOT), was synthesized. This compound forms a stable chelate with europium (III) and can be used as a fluorescence label for time-resolved fluorescence spectrometry. BCOT can be covalently bound to a protein under relatively mild conditions and, when complexed with europium(III), both in 0.1 M Tris-HCl solution and 1.0 x 10(-5) M tri-n-octyl phosphine oxide (TOPO)-0.05% sodium n-dodecyl sulfate (SDS)-0.1 M NaHCO3 solution, forms a strongly fluorescent chelate having lifetimes of 225 microseconds and 240 microseconds, respectively. As a model reaction, bovine serum albumin (BSA) was labeled with BCOT in a carbonate buffer solution. Fluorescence properties of the labeled BSA solution were studied. A time-resolved fluorescence determination of the BSA(BCOT)40-Eu3+ solution was carried out. Detection limits of 9.3 x 10(-14) M (TOPO-SDS-NaHCO3 solution) and 6.7 x 10(-13) M (Tris-HCl solution) for BSA were obtained by the method.
Animals↗
Transducing signals of life and death.
The molecules that form signaling complexes with the cytoplasmic domains of tumor necrosis factor (TNF) receptors (TNF-Rs) and CD95 have been identified recently. The death-signaling pathways induced by TNF-R1 and CD95 involve a group of death domain containing proteins, including caspase-8, a member of the interleukin-1beta-converting enzyme family. TNF-R1 and TNF-R2 also interact with the members of both the TNF-R associated factor family and the inhibitor of apoptosis protein family; these interactions lead to cell survival.
Animals↗
Direct demonstration of MuSK involvement in acetylcholine receptor clustering through identification of agonist ScFv.
MuSK is a tyrosine kinase localized to the postsynaptic surface of the neuromuscular junction. We have searched for modulators of MuSK function using a library of human single chain variable region antibodies (scFv) that can be displayed on M13 phage or expressed as soluble protein. A panel of 21 independent MuSK-specific scFv, identified in a screen for binding to MuSK-Fc immunoadhesin, were examined for ability to induce proliferation in a factor dependent cell line (Ba/F3) through a chimeric receptor, MuSK-Mpl. Four of the scFv induced a proliferative response, suggesting an ability to induce dimerization of MuSK. These scFv were also able to induce tyrosine phosphorylation of full-length MuSK and retained this ability when re-engineered to be expressed as authentic (and dimeric) human IgG molecules. Addition of agonist scFv to a cultured myotube cell line induced AChR clustering and tyrosine phosphorylation. These results provide direct evidence that MuSK activation is capable of triggering a key event in neuromuscular junction formation and further demonstrate that large libraries of phage-displayed scFv provide a robust method for generating highly specific agonist agents.
Amino Acid Sequence↗
Attenuation of transient focal cerebral ischemic injury in transgenic mice expressing a mutant ICE inhibitory protein.
We used transgenic mice expressing a dominant negative mutation of interleukin-1 beta converting enzyme (ICE) (C285G) in a model of transient focal ischemia in order to investigate the role of ICE in ischemic brain damage. Transgenic mutant ICE mice (n = 11) and wild-type littermates (n = 9) were subjected to 3 h of middle cerebral artery occlusion followed by 24 h of reperfusion. Cerebral infarcts and brain swelling were reduced by 44% and 46%, respectively. Neurological deficits were also significantly reduced. Regional CBF, blood pressure, core temperature, and heart rate did not differ between groups when measured for up to 1 h after reperfusion. Increases in immunoreactive IL-1 beta levels, observed in ischemic wild-type brain at 30 min after reperfusion, were 77% lower in the mutant strain, indicating that proIL-1 beta cleavage is inhibited in the mutants. DNA fragmentation was reduced in the mutants 6 and 24 h after reperfusion. Hence, endogenous expression of an ICE inhibitor confers resistance to cerebral ischemia and brain swelling. Our results indicate that downregulation of ICE expression might provide a useful therapeutic target in cerebral ischemia.
Animals↗
Acceleration of the maturation of oligodendroblasts into oligodendrocytes and enhancement of their myelinogenic properties by a chemically defined medium.
Because of the importance of oligodendrocytes (OL) in forming and maintaining myelin in the CNS and the fact that the remyelination in the CNS is very limited in contrast to the peripheral nervous system, we investigated the effect of a chemically defined medium OLDEM, previously characterized by the maintenance of mature myelinating OL, on oligodendroblasts (or OL progenitors) in culture. The effect of each component of this medium as well as different combinations of them were also examined. Cultures were examined at different developmental stages immunocytochemically for developmental markers, such as transferrin, sulfatides, myelin basic protein and proteolipid protein. OLDEM accelerated the appearance of developmental markers and concomitant morphological changes. Furthermore, myelin-specific enzymes such as glycerophosphorylcholine phosphodiesterase; p-nitro-phenolphosphocholine phosphodiesterase; 2'3'-cyclic nucleotide 3'-phosphodiesterase and UDP galactose: ceramide galactosyltransferase had enzymatic activities similar to values found in pure myelin, indicating that OLDEM allows the optimal expression of myelin-related genes. The effect of each OLDEM constituent was evaluated by immunocytochemistry and by measurement of enzymatic activities. With each single additive or multiple combinations, oligodendrocytes displayed different degrees of maturation. Deletion of selenium, glucose, and galactose severely affected cell survival as well as enzymes expression in young cultures. However, older cultures were more resistant to these deletions. Putrescine and insulin did not cause such effects on survival, but their absence affected cell maturation. None of the OLDEM additives individually supported survival and/or maturation. Enzyme assays performed on isolated myelin-like membranes or the cells soma revealed a redistribution of the activity between these fractions as the cell matured. The biological role of each of these constituents on the maturation of the oligodendroglial cells is discussed. These observations indicate that OLDEM constituents have a powerful effect on OL progenitor maturation, and membrane formation. This medium will be used for investigating the remyelination potential of adult OL progenitors.
Animals↗
Family and cultural correlates of depression among Chinese elderly.
This study hypothesized that depressive experiences of the elderly could be aggravated by universal factors such as low social status, poor health, financial strain, and unhealthy lifestyle, as well as by factors specific to an indigenous socio-cultural environment (stressful family dynamics) of a given population. Three hundred and fifty Chinese subjects aged 65 or older were interviewed either at their homes or in the geriatric out-patient clinic of Beijing Hospital. Hierarchical logistic regression was used to examine significant predictors of depression. Results showed that certain social status, poor physical health, financial strain, unhealthy lifestyle, and stressful family situation explained 47 percent of the variance in depression. However, stressful family situation alone explained 13 percent of the variance in depression, indicating that family factors were important predictors of depression for Chinese elderly. Furthermore, this study demonstrated for the first time that verbal abuse within Chinese families is a significant correlate of depression among the elderly. Cultural implications of these findings are discussed.
Aged↗
A C. elegans E/Daughterless bHLH protein marks neuronal but not striated muscle development.
The E proteins of mammals, and the related Daughterless (DA) protein of Drosophila, are ubiquitously expressed helix-loop-helix (HLH) transcription factors that play a role in many developmental processes. We report here the characterization of a related C. elegans protein, CeE/DA, which has a dynamic and restricted distribution during development. CeE/DA is present embryonically in neuronal precursors, some of which are marked by promoter activity of a newly described Achaete-scute-like gene hlh-3. In contrast, we have been unable to detect CeE/DA in CeMyoD-positive striated muscle cells. In vitro gel mobility shift analysis detects dimerization of CeE/DA with HLH-3 while efficient interaction of CeE/DA with CeMyoD is not seen. These studies suggest multiple roles for CeE/DA in C. elegans development and provide evidence that both common and alternative strategies have evolved for the use of related HLH proteins in controlling cell fates in different species.
Amino Acid Sequence↗
[Promotive effects of basic fibroblast growth factor on proliferation of bovine lens epithelial cells].
OBJECTIVE: In order to observe the effect of basic fibroblast growth factor (bFGF) on bovine lens epithelial cell growth. METHODS: Primary culture and subculture of bovine lens epithelial cells were established in vitro first and then bFGF concentrated from 10(-2) ng/ml to 10(2) ng/ml was added to the epithelial cells of second passage respectively. The proliferative characteristics of the cells were measured with methyl thiazolyl tetrazolium (MTT) assay method. RESULTS: It is indicated that in vitro bovine epithelial cells are characterized by easy adherence, rapid confluence, high growth, etc. After the treatment with bFGF, lens epithelial cells showed marked proliferation depending on the concentration of bFGF from 1 ng/ml to 10(2) ng/ml, especially in 10(2) ng/ml of bFGF. CONCLUSION: It is suggested that bFGF play an important role in lens epithelial cell proliferation and posterior capsular opacities after cataract surgery.
Animals↗