Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cowpox virus (CPV) CrmA and the equivalent rabbitpox virus (RPV) SPI-2 proteins have anti-inflammatory and antiapoptosis activity by virtue of their ability to inhibit caspases, including the interleukin-1beta-converting enzyme (ICE; caspase-1). Infection of LLC-PK1 pig kidney cells with a CPV CrmA mutant, but not with wild-type (wt) CPV, results in the induction of many of the morphological features of apoptosis (C. A. Ray and D. J. Pickup, Virology 217:384-391, 1996). In our study, LLC-PK1 cells infected with CPV delta crmA, but not those infected with wt CPV, showed induction of poly(ADP-ribose) polymerase (PARP)- and lamin A-cleaving activities and processing of the CPP32 (caspase-3) precursor to a mature 18-kDa form. Surprisingly, infection of LLC-PK1 cells with either wt RPV (despite the presence of the SPI-2 protein) or RPV delta SPI-2 resulted in cleavage activity against PARP and lamin A and the appearance of the mature subunit of CPP32/caspase-3. The biotinylated specific peptide inhibitor Ac-Tyr-Val-Lys(biotinyl)-Asp-2,6-dimethylbenzoyloxymethylketone [AcYV(bio)KD-aomk] labeled active caspase subunits of 18, 19, and 21 kDa in extracts from LLC-PK1 cells infected with CPV delta crmA, wt RPV, or RPV delta SPI-2 but not wt CPV. Mixed infection of LLC-PK1 cells with wt RPV and wt CPV gave no PARP-cleaving activity, and all PARP cleavage mediated by SPI-2 and CrmA mutants of RPV and CPV, respectively, could be eliminated by coinfection with wt CPV. These results suggest that the RPV SPI-2 and CPV CrmA proteins are not functionally equivalent and that CrmA, but not SPI-2 protein, can completely prevent apoptosis in LLC-PK1 cells under these conditions.
 ...
PMID:Activation of caspases in pig kidney cells infected with wild-type and CrmA/SPI-2 mutants of cowpox and rabbitpox viruses. 955 31

Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Their proposed protective role in tumor development may prevail especially in the intestinal tract due to direct exposure of intestinal epithelia to these dietary ingredients. We have screened more than 30 flavonoids for their effects on cell proliferation and potential cytotoxicity in the human colon cancer cell lines Caco-2, displaying features of small intestinal epithelial cells, and HT-29, resembling colonic crypt cells. In addition, for selected compounds we assessed whether they induce apoptosis by determining caspase-3 activation. Studies on the dose dependent effects of the flavonoids showed antiproliferative activity of all compounds with EC50 values ranging between 39.7 +/- 2.3 microM (baicalein) and 203.6 +/- 15.5 microM (diosmin). In almost all cases, growth inhibition by the flavonoids occurred in the absence of cytotoxicity. There was no obvious structure-activity relationship in the antiproliferative effects either on basis of the subclasses (i.e., isoflavones, flavones, flavonols, flavonones) or with respect to kind or position of substituents within a class. In a subset of experiments we examined the antiproliferative activities of the most potent compound of each flavonoid subgroup in addition in LLC-PK1, a renal tubular cell line, and the human breast cancer cell line MCF-7. Out of four flavonols tested, three displayed almost equal antiproliferative activities in all cell lines but fisetin was less potent in MCF-7 cells. The flavanones bavachinin and flavanone inhibited growth of Caco-2 and HT-29 cells with lower EC50 values than that obtained in LLC-PK1 and MCF-7 cells. The lower susceptibility of LLC-PK1 and MCF-7 cells towards growth arrest was even more pronounced in the case of the flavone baicalein. Half maximal growth-inhibition in LLC-PK1 and MCF-7 required 2.5 and 6.6 fold higher concentrations than that needed in the intestinal cell lines. The flavonoids failed to affect apoptosis in LLC-PK1 and MCF-7, whereas baicalein and myricetin were able to induce apoptosis in HT-29 and Caco-2 cells. In conclusion, flavonoids of the flavone, flavonol, flavanone, and isoflavone classes possess antiproliferative effects in different cancer cell lines. The capability of flavonoids for growth inhibition and induction of apoptosis can not be predicted on the basis of their chemical composition and structure.
 ...
PMID:Comparative analysis of the effects of flavonoids on proliferation, cytotoxicity, and apoptosis in human colon cancer cell lines. 1044 35

The kidney is a target for toxicants including cisplatin and S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a metabolite of the environmental contaminant, trichloroethylene. Necrosis is well characterized in kidney cells, but pathways leading to apoptosis are less clear. Cysteine conjugates are useful toxicants because they induce either necrosis or apoptosis depending on chemical structure or antioxidant status. Herein, we show that in the renal epithelial cell line LLC-PK1, activation of caspase-3 (CPP32/Yama/apopain) is crucial for apoptosis, but not necrosis. Apoptosis was blocked by zVAD.fmk, and partially by a cathepsin inhibitor. Caspase-3 activity and cleavage of poly(ADP-ribose) polymerase (PARP) was detected only during apoptosis. S-(1,1,2,2-Tetrafluoroethyl)-L-cysteine (TFEC), a metabolite of tetrafluoroethylene, kills cells only by necrosis, and did not activate caspases under any conditions. Apoptosis and activation of caspase-3 by cisplatin, but not DCVC, was prevented by bcl-2. Thus, caspase-3 activation by bcl-2-dependent and -independent mechanisms is a terminal event in chemical-apoptosis of renal epithelial cells.
 ...
PMID:The roles of caspase-3 and bcl-2 in chemically-induced apoptosis but not necrosis of renal epithelial cells. 1059 53

Renal failure associated with aspergillosis is caused by pathogenic fungi. Gliotoxin is a toxic epipolythiodioxopiperazine metabolite produced by the pathogens. The present study investigated the cytotoxicity and underlying mechanisms induced by gliotoxin in LLC-PK1 cells, a porcine renal proximal tubular cell line. Gliotoxin at 100 ng/ml did not show a cytotoxic effect, but unmasked a dose-dependent cell death induced by TNF-alpha. TNF-alpha-induced cell death in the presence of gliotoxin was associated with hypodiploid nuclei and activation of caspase-3-like proteases. Blockade of caspases by boc-aspartyl (OMe)-fluoromethylketone and z-DEVD.fmk inhibited TNF-alpha-induced cell death. As the concentrations of gliotoxin were increased, gliotoxin killed the cells directly in a dose-dependent manner. Further analyses of DNA fragmentation, hypodiploid nuclei, mitochondrial membrane potential, and plasma membrane integrity revealed that cell death proceeded via apoptosis. Gliotoxin-induced apoptosis was associated with dose-dependent and time-dependent activation of caspase-3-like proteases. Boc-aspartyl (OMe)-fluoromethylketone attenuated the killing effect. Gliotoxin also increased the intracellular levels of reactive oxygen species as measured by flow cytometry. N-acetylcysteine, a well-known antioxidant, completely abolished the gliotoxin-induced caspase-3-like activity, cytotoxicity, and reactive oxygen species. In conclusion, (1) gliotoxin at 100 ng/ml unmasks the ability of TNF-alpha-induced apoptosis, and the effect of TNF-alpha is mediated by caspase-3-like proteases; and (2) at higher concentrations gliotoxin itself induces cell death, which is via apoptosis and dependent on caspase-3-like activity and reactive oxygen species.
 ...
PMID:Gliotoxin-induced cytotoxicity proceeds via apoptosis and is mediated by caspases and reactive oxygen species in LLC-PK1 cells. 1074 46

Disulfiram, a clinically employed alcohol deterrent, was recently discovered to inhibit caspase-3 and DNA fragmentation. Using LLC-PK1 cells and murine liver as models, we examined if the drug inhibited TNF-alpha-induced cell death. Disulfiram produced dose-dependent inhibition of TNF-alpha-induced cell death as well as caspase-3-like activity. Disulfiram retained 80% of its effect when added 4 h after TNF-alpha. Disulfiram protected the cells from cytokine-induced death for at least 6 days. The cells rescued by the drug preserved the ability to proliferate. The cells died spontaneously after exposure to TNF-alpha for just 70 min. Co-administration of 15 microM disulfiram and TNF-alpha for 70 min prior to their removal abolished TNF-alpha-induced killing, and this was associated with restoration of mitochondrial membrane potential and suppression of reactive oxygen species. Treatment of mice with TNF-alpha and D-galactosamine for 5 h markedly increased hepatic DNA fragmentation and caspase-3-like activity. Disulfiram at 0.6 mmol/kg abolished these effects. We conclude that disulfiram is a potent inhibitor of TNF-alpha-induced cell death in vitro. The underlying mechanisms include stabilization of mitochondrial membrane potential, suppression of reactive oxygen species, and inhibition of caspase-3-like activity. We further conclude that disulfiram inhibits DNA fragmentation in vivo in association with the blockade of caspase-3-like activity.
 ...
PMID:Disulfiram inhibits TNF-alpha-induced cell death. 1097 95

The nephrotoxicity of trichloroethylene and dichloroacetylene has previously been linked to mitochondrial dysfunction induced by the metabolite S-(1,2-dichlorovinyl)-l-cysteine (DCVC). In this study, we examined whether key biochemical steps associated with mitochondria occur in DCVC-induced apoptosis in cultured porcine proximal tubular LLC-PK1 cells. DCVC caused a decrease in mitochondrial membrane potential (mt Delta Psi) beginning at 4 h and a release of cytochrome c into the cytoplasm at 6 h. Caspase-3-like activity was detected at 6 h and extensive DNA fragmentation was observed at 8 h. Decreases in cellular ATP were not evident until 8 h and later, even though electron microscopy showed that the mitochondria were extensively swollen. Aminooxyacetic acid (AOAA), an inhibitor of cysteine-conjugate beta-lyase, protected against mitochondrial changes and apoptosis. Overexpression of the antiapoptotic Bcl-2 protein desensitized LLC-PK1 cells to DCVC-induced apoptosis. These results support the interpretation that mitochondrial release of cyt c and cyt c-dependent activation of caspase-3 could have a central role in nephrotoxicity due to haloalkene-derived cysteine S-conjugates.
 ...
PMID:Role of mitochondrial dysfunction in S-(1,2-dichlorovinyl)-l-cysteine-induced apoptosis. 1116 82

12-O-Tetradecanoylphorbol-13-acetate (TPA) induced apoptosis in the pig renal epithelial cell line LLC-PK1 after 24 h of treatment as assessed by caspase 3 activation. Cotreatment of the cells with bryostatin markedly reduced the apoptotic effects of TPA. Okadaic acid, another tumor promoter, also induced apoptosis. Expression of an activated ras gene prevented TPA-induced apoptosis, while a dominant negative ras retarded the process. Taken together, these results suggest that TPA-induced apoptosis in LLC-PK1 may be analogous to TPA-induced tumor promotion in the two-stage model of skin carcinogenesis. Mechanistically, TPA-induced apoptosis seemed to be the result of a conflict of the growth-promoting affects of serum and the growth-retarding effects of TPA. This was manifested by a pronounced hypophosphorylation of the retinoblastoma gene product, pRb, which was prevented by activated ras. Apoptosis and pRb hypophosphorylation were associated with a reduction in cyclin D1 levels, suggesting that the growth-retarding effects of TPA were produced by modulation of this cell cycle protein. Interestingly, the mechanism of protection by activated ras did not seem to result from downstream activation of phosphatidylinositol-3-kinase (PI3K) as has been implicated in other systems. Additional analysis revealed that TPA-induced apoptosis was associated with the downregulation of the anti-apoptotic proteins Bcl-x and Mcl-1 and dependent on the activity of the transcription factor Jun.
 ...
PMID:12-O-tetradecanoylphorbol-13-acetate induces apoptosis in renal epithelial cells through a growth signal conflict which is prevented by activated ras. 1136 20

Decreased phosphorylation of focal adhesion kinase (FAK) is associated with loss of focal adhesions and actin stress fibers and precedes the onset of apoptosis in renal epithelial cells caused by nephrotoxicants (Van de Water, B., Nagelkerke, J. F., and Stevens, J. L. (1999) J. Biol. Chem. 274, 13328-13337). The role of FAK in the control of apoptosis caused by nephrotoxicants was further investigated in LLC-PK1 cells that were stably transfected with either green fluorescent protein (GFP)-FAK or dominant negative acting deletion mutants of FAK, GFP-FAT, and GFP-FRNK. GFP-FAT and GFP-FRNK delayed the formation of focal adhesions and prevented the localization of endogenous (phosphorylated) FAK at these sites. GFP-FAT and GFP-FRNK overexpression potentiated the onset of apoptosis caused by the nephrotoxicant dichlorovinyl-cysteine. This was associated with an increased activation of caspase-3. GFP-FAT also potentiated apoptosis caused by doxorubicin but not cisplatin. The potentiation of apoptosis by GFP-FAT was related to an almost complete dephosphorylation of FAK; this did not occur in cells overexpressing only GFP. This dephosphorylation was associated with a pronounced loss of focal adhesion organization in GFP-FAT cells, in association with loss of tyrosine phosphorylation of paxillin. In conclusion, the data indicate an important role of cell-matrix signaling in the control of chemically induced apoptosis; loss of FAK activity caused by toxic chemicals results in perturbations of focal adhesion organization with a subsequent inactivation of associated (signaling) molecules and loss of survival signaling.
 ...
PMID:Suppression of chemically induced apoptosis but not necrosis of renal proximal tubular epithelial (LLC-PK1) cells by focal adhesion kinase (FAK). Role of FAK in maintaining focal adhesion organization after acute renal cell injury. 1144 17

Colloidal bismuth subcitrate (CBS), a drug for treatment of peptic ulcers, has been reported in the literature to be nephrotoxic in humans when taken in high overdoses. To investigate the mechanism of bismuth nephropathy, we developed an animal model by feeding rats single doses of CBS containing 3.0 mmol Bi/kg body weight. Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling assay, immunostaining for active caspase-3, and electron microscopy showed that proximal tubular epithelial cells die by necrosis and not by apoptosis within 3 h after CBS administration. Exposure of the renal epithelial cell lines NRK-52E and LLC-PK1 to Bi(3+) in citrate buffer served as an in vitro model of bismuth nephropathy. NRK-52E cells exposed to 100 microM Bi(3+) or more died by necrosis, as was demonstrated by nuclear staining with Hoechst 33258 and flow cytometry using Alexa(488)-labeled Annexin-V and the vital nuclear dye TOPRO-3. Bismuth-induced cell death of NRK-52E cells was not prevented by the caspase-3 inhibitor z-VAD-fmk, whereas this inhibitor did prevent cisplatinum-induced apoptosis. Mitochondrial dysfunction and induction of free radicals were shown not to be involved in bismuth nephrotoxicity. The early time point of damage induction in vitro as well as in vivo and the early displacement of N-cadherin, as found in previous studies, suggest that bismuth induces cell death by destabilizing the cell membrane. In conclusion, we showed that high overdose of bismuth induced cell death by necrosis in vivo as well as in vitro, possibly by destabilization of the cell membrane.
 ...
PMID:Pathways of proximal tubular cell death in bismuth nephrotoxicity. 1196 77

Cadmium chloride (CdCl(2)) is a nephrotoxicant that causes damage to the proximal tubular epithelium. In vivo, it increases the permeability of epithelial surfaces, while in vitro, it acts on active trans-epithelial ion transport. The purpose of this study was to investigate CdCl(2) effects on a porcine renal proximal tubular epithelial cell line (LLC-PK1), and, in particular, to identify sensitive endpoints revealing damage both at the epithelial barrier level and at the molecular level. After exposure of the cells to CdCl(2), trans-epithelial resistance (TER) decreased while paracellular permeability (PCP) increased, indicating a structural alteration of the junctional complex. At the molecular level, we observed an increase in protective proteins, such as metallothioneins (MTs) and heat shock proteins (HSP70), starting from 25 microM CdCl(2), together with alterations in cytoskeleton organization. Production of reactive oxygen species (ROS) was also evident, indicating cellular oxidative stress. Our data indicate that CdCl(2) toxicity can be detected at the barrier level and at the molecular level at low concentrations, at which cytotoxicity assays are unable to show any damage. Therefore, these endpoints should prove very useful in studying heavy metal-induced acute toxicity. Exposure of the cells to higher concentrations of CdCl(2) (50 microM) revealed the initiation of apoptosis, mediated by caspase-3.
 ...
PMID:Sensitive endpoints for evaluating cadmium-induced acute toxicity in LLC-PK1 cells. 1250 52


1 2 3 4 5 6 Next >>