Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumors generally display a high glycolytic rate. One consequence of increased glycolysis is the non-enzymatic glycation of proteins leading to the formation of advanced glycation end-products (AGEs). Therefore, we studied the presence of AGEs in non-small cell lung cancer and consequences thereof. We show the presence of two AGEs, i.e. the major AGE N(epsilon)-(carboxymethyl)lysine (CML) and the methylglyoxal-arginine adduct argpyrimidine, in human non-small cell lung cancer tissues by immunohistochemistry. We found in squamous cell carcinoma and adenocarcinoma tissues a strong CML positivity in both tumour cells and tumour-surrounding stroma. In contrast, argpyrimidine positivity was predominantly found in tumor cells and was strong in squamous cell carcinomas, but only weak in adenocarcinomas (2.6+/-0.5 vs. 1.2+/-0.4, respectively; P<0.005). In accordance, argpyrimidine was found in the human lung squamous carcinoma cell line SW1573, while it was almost absent in the adenocarcinoma cell line H460. Heat shock protein 27 (Hsp27) was identified as a major argpyrimidine-modified protein. In agreement with a previously described anti-apoptotic activity of argpyrimidine-modified Hsp27, the percentage of active caspase-3 positive tumor cells in squamous cell carcinomas was significantly lower when compared to adenocarcinomas. In addition, incubation with cisplatin induced almost no caspase-3 activation in SW1573 cells while a strong activation was seen in H460 cells; which was significantly reduced by incubation with an inhibitor of glyoxalase I, the enzyme that catalyzes the conversion of methylglyoxal. These findings suggest that a high level of argpyrimidine-modified Hsp27 is a mechanism of cancer cells for evasion of apoptosis.
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PMID:Argpyrimidine-modified Heat shock protein 27 in human non-small cell lung cancer: a possible mechanism for evasion of apoptosis. 1633 38

The subfamily of WNK (with no K= lysine) protein kinases has four human members and germline mutations in the WNK1 and WNK4 genes were recently found to cause pseudohypoaldosteronism type II, a familial hypertension disease. Here, we describe cloning and functional analysis of a further WNK member, human WNK3. Endogenous WNK3 protein is an active protein kinase when immunoprecipitated from cells and its overexpression increases the survival of HeLa cells by delaying the onset of apoptosis. Suppression of endogenous WNK3 protein by RNA interference accelerates the apoptotic response and promotes the activation of caspase-3. The mechanism of WNK3 action involves interaction with procaspase-3 and heat-shock protein 70. These results demonstrate a role for WNK3 in promoting cell survival and suggest a mechanism at the level of procaspase-3 activation.
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PMID:Protein kinase WNK3 increases cell survival in a caspase-3-dependent pathway. 1650 4

The development of phenyldithioethyloxycarbonyl (Phdec) and 2-pyridyldithioethyloxycarbonyl (Pydec) protecting groups, which are thiol-labile urethanes, is described. These new disulfide-based protecting groups were introduced onto the epsilon-amino group of L-lysine; the resulting amino acid derivatives were easily converted into N alpha-Fmoc building blocks suitable for both solid- and solution-phase peptide synthesis. Model dipeptide(Ardec)s were prepared by using classical peptide couplings followed by standard deprotection protocols. They were used to optimize the conditions for complete thiolytic removal of the Ardec groups both in aqueous and organic media. Phdec and Pydec were found to be cleaved within 15 to 30 min under mild reducing conditions: i) by treatment with dithiothreitol or beta-mercaptoethanol in Tris.HCl buffer (pH 8.5-9.0) for deprotection in water and ii) by treatment with beta-mercaptoethanol and 1,8-diazobicyclo[5.4.0]undec-7-ene (DBU) in N-methylpyrrolidinone for deprotection in an organic medium. Successful solid-phase synthesis of hexapeptides Ac-Lys-Asp-Glu-Val-Asp-Lys(Ardec)-NH2 has clearly demonstrated the full orthogonality of these new amino protecting groups with Fmoc and Boc protections. The utility of the Ardec orthogonal deprotection strategy for site-specific chemical modification of peptides bearing several amino groups was illustrated firstly by the preparation of a fluorogenic substrate for caspase-3 protease containing the cyanine dyes Cy 3.0 and Cy 5.0 as FRET donor/acceptor pair, and by solid-phase synthesis of an hexapeptide bearing a single biotin reporter group.
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PMID:Aryldithioethyloxycarbonyl (Ardec): a new family of amine protecting groups removable under mild reducing conditions and their applications to peptide synthesis. 1651 83

Advanced glycation end products (AGEs) are elevated in aged and diabetic individuals and are associated with pathological changes associated with both. Previously we demonstrated that the AGE N(epsilon)-(carboxymethyl)lysine (CML)-collagen induced fibroblast apoptosis through the cytoplasmic and mitochondrial pathways and the global induction of proapoptotic genes. In the present study we investigated upstream mechanisms of CML-collagen-induced apoptosis. CML-collagen induced activation of the proapoptotic transcription factor FOXO1 compared with unmodified collagen. When FOXO1 was silenced, CML-collagen-stimulated apoptosis was reduced by approximately 75% compared with fibroblasts incubated with nonsilencing small interfering RNA, demonstrating the functional significance of FOXO1 activation (P < 0.05). CML-collagen but not control collagen also induced a 3.3-fold increase in p38 and a 5.6-fold increase in JNK(1/2) activity (P < 0.05). With the use of specific inhibitors, activation of p38 and JNK was shown to play an important role in CML-collagen-induced activation of FOXO1 and caspase-3. Moreover, inhibition of p38 and JNK reduced CML-collagen-stimulated apoptosis by 48 and 57%, respectively, and by 89% when used together (P < 0.05). In contrast, inhibition of the phosphatidylinositol 3-kinase/Akt pathway enhanced FOXO1 activation. p38 and JNK stimulation by CML-collagen was almost entirely blocked when formation of ROS was inhibited and was partially reduced by NO and ceramide inhibitors. These inhibitors also reduced apoptosis to a similar extent. Together these data support a model in which AGE-induced apoptosis involves the formation of ROS, NO, and ceramide and leads to p38 and JNK MAP kinase activation, which in turn induces FOXO1 and caspase-3.
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PMID:Advanced glycation end products induce apoptosis in fibroblasts through activation of ROS, MAP kinases, and the FOXO1 transcription factor. 1700 4

We have previously shown that diabetes significantly enhances apoptosis of osteoblastic cells in vivo and that the enhanced apoptosis contributes to diabetes impaired new bone formation. A potential mechanism is enhanced apoptosis stimulated by advanced glycation end products (AGEs). To investigate this further, an advanced glycation product, carboxymethyl lysine modified collagen (CML-collagen), was injected in vivo and stimulated a 5-fold increase in calvarial periosteal cell apoptosis compared to unmodified collagen. It also induced apoptosis in primary cultures of human or neonatal rat osteoblastic cells or MC3T3-E1 cells in vitro. Moreover, the apoptotic effect was largely mediated through RAGE receptor. CML-collagen increased p38 and JNK activity 3.2- and 4.4-fold, respectively. Inhibition of p38 and JNK reduced CML-collagen stimulated apoptosis by 45% and 59% and by 90% when used together (P<0.05). The predominant apoptotic pathway induced by CML-collagen involved caspase-8 activation of caspase-3 and was independent of NF-kappaB activation. When osteoblastic cells were exposed to a long-term low dose incubation with CML-collagen, there was a higher degree of apoptosis compared to short-term incubation. In more differentiated osteoblastic cultures, apoptosis was enhanced even further. These results indicate that advanced glycation end products, which accumulate in diabetic and aged individuals, may promote apoptosis of osteoblastic cells and contribute to deficient bone formation.
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PMID:Advanced glycation end products stimulate osteoblast apoptosis via the MAP kinase and cytosolic apoptotic pathways. 1706 73

Posttranslational histone methylation has been correlated with transcriptional regulation. However, the functional significance of methylation of lysine residues of histone remains largely unknown. Previously, we have characterized a novel histone methyltransferase (HMTase), WHISTLE which methylates histone H3-K4 and H3-K27 to repress transcription. In this study, we demonstrated that WHISTLE can induce apoptotic cell death through caspase-3 activation and that HMTase activity is important for the apoptosis induction. Deletion mapping analysis elicited that N-terminus PWWP region is required for HMTase activity by interacting with putative associating factors. Point mutant analysis revealed that SET domain cysteine 297 is a critical residue for the HMTase activity of WHISTLE. WHISTLE repressed transcription through HDAC1 recruitment possibly through the N-terminus region. Our results suggest that HMTase WHISTLE induces apoptosis in an HMTase activity-dependent manner and represses transcription of target genes through HDAC1 recruitment.
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PMID:The histone methyltransferase activity of WHISTLE is important for the induction of apoptosis and HDAC1-mediated transcriptional repression. 1723 52

The synthesis and photophysical properties of a new terpyridine-based europium(III) chelate (Eu (TMT)-AP3) designed for peptide and protein labelling in aqueous solution phase is described. In order to obtain a stable, easy to handle, versatile and efficient labelling agent, a reactive aminopropargyl arm has been introduced onto the terpyridine moiety. As preliminary biochemical applications the chelate has been 1) efficiently covalently attached onto a representative biomolecule-monoclonal antibody-and 2) converted into iodoacetamido and aldehyde derivatives, and the photoluminescent Eu (TMT)-AP3 was grafted onto cysteine and lysine amino acid residues respectively. These two different solution phase labelling methods yielded original fluorogenic FRET based probes suitable for "in vitro" detection of caspase-3 protease, a key mediator of apoptosis of mammalian cells.
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PMID:Aminopropargyl derivative of terpyridine-bis(methyl-enamine) tetraacetic acid chelate of europium (Eu (TMT)-AP3): a new reagent for fluorescent labelling of proteins and peptides. 1731 73

Since the signal transduction mechanisms responsible for liver regeneration mediated by the plasminogen/plasmin system remain largely undetermined, we have investigated whether plasmin regulates the pro-apoptotic protein Bim(EL) in primary hepatocytes. Plasmin bound to hepatocytes in part via its lysine binding sites (LBS). Plasmin also triggered phosphorylation of ERK1/2 without cell detachment. The plasmin-induced phosphorylation of ERK1/2 was inhibited by the LBS inhibitor epsilon-aminocaproic acid (EACA), the serine protease inhibitor aprotinin, and the MEK inhibitor PD98059. DFP-inactivated plasmin failed to phosphorylate ERK1/2. Plasmin temporally decreased the starvation-induced expression of Bim(EL) and activation of caspase-3 via the ERK1/2 signaling pathway, resulting in an enhancement of cell survival. The amount of mRNA for Bim increased 1 day after the injection of CCl(4) in livers of plasminogen knockout (Plg-KO) and the wild-type (WT) mice. The increase in Bim(EL) protein persisted for at least 7 days post-injection in livers of Plg-KO mice, whereas WT mice showed an increase in Bim(EL) protein 1 day after the injection. Plg-KO and WT mice showed notable phosphorylation of ERK1/2 7 and 3 days after the injection of CCl(4), respectively. Our data suggest that the plasminogen/plasmin system could decrease Bim(EL) expression via the ERK1/2 signaling pathway during liver regeneration.
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PMID:Plasmin decreases the BH3-only protein BimEL via the ERK1/2 signaling pathway in hepatocytes. 1748 86

The tripeptide-copper complex, described as a growth factor for various kinds of differentiated cells, stimulates the proliferation of dermal fibroblasts and elevates the production of vascular endothelial growth factor, but decreased the secretion of transforming growth factor-beta1 by dermal fibroblasts. Dermal papilla cells (DPCs) are specialized fibroblasts, which are important in the morphogenesis and growth of hair follicles. In the present study, the effects of L-alanyl-L-histidyl-L-lysine-Cu2+ (AHK-Cu) on human hair growth ex vivo and cultured dermal papilla cells were evaluated. AHK-Cu (10(-12) - 10(-9) M) stimulated the elongation of human hair follicles ex vivo and the proliferation of DPCs in vitro. Annexin V-fluorescein isothiocyanate/propidium iodide labeling and flow cytometric analysis showed that 10(-9) M AHK-Cu reduced the number of apoptotic DPCs, but this decrease was not statistically significant. The ratio of Bcl-2/Bax was elevated, and the levels of the cleaved forms of caspase-3 and PARP were reduced by treatment with 10(-9) M AHK-Cu. The present study proposed that AHK-Cu promotes the growth of human hair follicles, and this stimulatory effect may occur due to stimulation of the proliferation and the preclusion of the apoptosis of DPCs.
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PMID:The effect of tripeptide-copper complex on human hair growth in vitro. 1770 34

Electrophiles generated endogenously, or via the metabolic bioactivation of drugs and other environmental chemicals, are capable of binding to a variety of nucleophilic sites within proteins. Factors that determine site selective susceptibility to electrophile-mediated post-translational modifications, and the consequences of such alterations, remain largely unknown. To identify and characterize chemical-mediated protein adducts, electrophiles with known toxicity were utilized. Hydroquinone, and its mercapturic acid pathway metabolites, cause renal proximal tubular cell necrosis and nephrocarcinogenicity in rats. The adverse effects of HQ and its thioether metabolites are in part a consequence of their oxidation to the corresponding electrophilic 1,4-benzoquinones (BQ). We now report that BQ and 2-(N-acetylcystein-S-yl)benzoquinone (NAC-BQ) preferentially bind to solvent-exposed lysine-rich regions within cytochrome c. Furthermore, we have identified specific glutamic acid residues within cytochrome c as novel sites of NAC-BQ adduction. The microenvironment at the site of adduction governs both the initial specificity and the structure of the final adduct. The solvent accessibility and local pKa of the adducted and neighboring amino acids contribute to the selectivity of adduction. Postadduction chemistry subsequently alters the nature of the final adduct. Using molecular modeling, the impact of BQ and NAC-BQ adduction on cytochrome c was visualized, revealing the spatial rearrangement of critical residues necessary for protein-protein interactions. Consequently, BQ-adducted cytochrome c fails to initiate caspase-3 activation in native lysates and also inhibits Apaf-1 oligomerization into an apoptosome complex in a purely reconstituted system. In summary, a combination of mass spectroscopic, molecular modeling, and biochemical approaches confirms that electrophile-protein adducts produce structural alterations that influence biological function.
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PMID:Quinone electrophiles selectively adduct "electrophile binding motifs" within cytochrome c. 1782 17


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