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

Taurochenodeoxycholic acid (TCDCA), but not glycochenodeoxycholic acid (GCDCA), activates a phosphatidylinositol 3-kinase (PI3-K)-mediated survival pathway in vitro. Here, the effects of PI3-K inhibition on TCDCA- and GCDCA-induced hepatocellular injury, apoptosis, and bile secretion were examined in the intact liver. In isolated perfused rat livers, bile flow was determined gravimetrically. Hepatovenous lactate dehydrogenase and alanine aminotransferase efflux as markers of liver integrity and biliary secretion of 2,4-dinitrophenyl-S-glutathione (DNP-GS) were determined photometrically. Apoptosis was assessed by immunohistochemistry of active caspase-3 and cytokeratin 18 in liver tissue. Phosphorylation of protein kinase B (PKB/Akt) as a readout of PI3-K activity was determined by immunoblot analysis. Bile acid concentrations were determined by gas chromatography. TCDCA (25 muM) induced moderate liver injury by hepatocellular apoptosis and distinctly reduced bile flow and DNP-GS secretion. In contrast, GCDCA (25 muM) induced severe liver injury by extensive hepatocyte apoptosis. TCDCA strongly activated PI3-K, whereas GCDCA did not markedly affect PI3-K activity. Inhibition of PI3-K by 100 nM wortmannin enhanced TCDCA-induced liver injury and apoptosis and tended to aggravate the cholestatic effect of TCDCA. In contrast, wortmannin reduced GCDCA-induced liver injury and apoptosis. Bile acid uptake tended to be reduced by wortmannin. The cholestatic effect of GCDCA was aggravated by wortmannin. Inhibition of PI3-K markedly aggravated TCDCA-induced but not GCDCA-induced liver damage and hepatocyte apoptosis. Thus TCDCA appears to block its inherent toxicity by a PI3-K-dependent survival pathway in the intact liver.
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PMID:Phosphatidylinositol 3-kinase-dependent signaling modulates taurochenodeoxycholic acid-induced liver injury and cholestasis in perfused rat livers. 1574 12

We hypothesized that fibrin enhances apoptosis and modulates differentiation of trophoblast in vitro. Cytotrophoblasts isolated from normal term human placentas were cultured < or =72 h in DMEM-10%-FBS on a fibrin matrix in standard or hypoxic conditions. Trophoblasts were cultured on plastic (control), type I collagen (matrix control), or dishes with fibrinogen, fibrin degradation products (FDP), thrombin, plasma fibronectin or cellular fibronectin. Apoptosis was determined by western analysis of the cleavage products of poly-ADP-ribose polymerase and cytokeratin 18 and caspase 3 activity. Cell cycle regulation was quantified by expression of proliferating cell nuclear antigen (PCNA) and p27 protein. Differentiation was determined by media level of hCG and hPL. Compared to the two controls, fibrin matrix had no effect on trophoblast apoptosis or total cell death in standard conditions. Neither fibrin nor collagen altered expression of PCNA or p27. In contrast, fibrin significantly increased the secretion of both hCG and hPL. Fibrin, but not FDP, thrombin or fibronectins, promoted hormonal differentiation. Fibrin limited the impact of a < or =8h of hypoxia on trophoblast hormone release but did not avert the effects of 24h of low oxygen and did not alter apoptosis in hypoxic trophoblast. We conclude that fibrin provides an environment conducive for trophoblast re-epithelialization of the surface of villi, where injury is marked by fibrin deposition.
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PMID:Fibrin enhances differentiation, but not apoptosis, and limits hypoxic injury of cultured term human trophoblasts. 1595 63

We tested the hypothesis that the expression levels of p53 and the pro-apoptotic mediators from the Bcl-2 family are higher in cytotrophoblasts, when compared to cultures with abundant syncytiotrophoblasts. Cytotrophoblasts isolated from normal term human placentas were cultured in Dulbecco's Modified Eagle medium (DMEM) for 24 h, when the cytotrophoblast phenotype predominates, in DMEM for 72 h, when the syncytiotrophoblast phenotype predominates, or in Ham's-Waymouth medium or DMEM with 1.5% dimethylsulfoxide, each of which maintains the cytotrophoblast phenotype through 72 h of culture. Apoptosis was assessed by detection of cleavage products of poly-ADP-ribose polymerase, by expression of cleaved cytokeratin 18 intermediate filaments, and by assessment of caspase-3 activity. Independent of time in culture, cytotrophoblasts showed higher levels of apoptosis compared to syncytiotrophoblasts. Cytotrophoblasts also expressed a 2-fold higher level of p53, a 2-fold lower level of 60 kDa Mdm-2 protein, a 2-fold higher level of Bak, but no differences in the expression of 90 kDa Mdm-2, Bcl-2, Bcl-X(L), Mcl-1, Bax, Bad, and Bad phosphorylated at the serine(112), serine(136), or serine(155) sites, compared to the syncytiotrophoblasts. Using co-immunoprecipitation, we demonstrated a greater degree of Bak-p53 interaction in cytotrophoblasts than in syncytiotrophoblasts. We also detected Bak-Mcl-1 interaction that was no different between the two phenotypes. Among the proteins studied, enhanced p53 activity, differential Bak expression, and Bak-p53 interactions may contribute to the higher level of constitutive apoptosis in cultures of cytotrophoblasts compared to syncytiotrophoblasts.
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PMID:Enhanced basal apoptosis in cultured term human cytotrophoblasts is associated with a higher expression and physical interaction of p53 and Bak. 1637 85

In patients with nonalcoholic fatty liver disease (NAFLD), a liver biopsy remains the only reliable way to differentiate simple steatosis from nonalcoholic steatohepatitis (NASH). Noninvasive methods are urgently needed. Increasing evidence suggests hepatocyte apoptosis is a key mediator of liver injury in NAFLD. The aim of this study was to quantify hepatocyte apoptosis in plasma from patients with NAFLD and correlate it with histological severity. Plasma was obtained from 44 consecutive patients with suspected NAFLD at the time of liver biopsy. Histology was assessed blindly. Caspase-3-generated cytokeratin-18 fragments were measured in situ via immunohistochemistry and in vivo using a novel enzyme-linked immunosorbent assay. Plasma cytokeratin-18 fragments were markedly increased in patients with NASH compared with patients with simple steatosis or normal biopsies (median [interquartile range]: 765.7 U/L [479.6-991.1], 202.4 U/L [160.4-258.2], 215.5 U/L [150.2-296.2], respectively; P < .001). Cytokeratin-18 fragment levels independently predicted NASH (OR 1.95; 95% CI 1.18-3.22; P = .009 for every 50 U/L increase). A cutoff value of 395 U/L calculated using the receiver operating characteristic curve approach showed a specificity of 99.9%, a sensitivity of 85.7%, and positive and negative predictive values of 99.9% and 85.7%, respectively, for the diagnosis of NASH. In conclusion, these findings strongly suggest that determination of hepatocyte caspase activation in the blood is a strong and independent predictor of NASH in human subjects. These data highlight the potential usefulness of this test as a noninvasive diagnostic means of determining histological disease severity in patients with NAFLD.
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PMID:In vivo assessment of liver cell apoptosis as a novel biomarker of disease severity in nonalcoholic fatty liver disease. 1725 23

Intestinal epithelial cells migrate from the base of the crypt to the villi where they are shed. However, little is known about the cell shedding process. We have studied the role of apoptosis and wound healing mechanisms in cell shedding from human small intestinal epithelium. A method preparing paraffin sections of human small intestine that preserves cell shedding was developed. A total of 14 417 villus sections were studied. The relationship of cell shedding to leukocytes (CD45), macrophages (CD68) and blood vessels (CD34) were studied by immunohistochemistry. Apoptotic cells were identified using the M30 antibody against cleaved cytokeratin 18 and an antibody against cleaved caspase-3. Potential wound healing mechanisms were studied using antibodies against Zona Occludens-1 (ZO-1) and phosphorylated myosin light chains (MLCs). We found that 5.3% of villus sections contained a shedding cell. An eosin-positive gap was often seen within the epithelial monolayer beneath shedding cells. Shedding was not associated with leukocytes, macrophages or blood vessels. Cells always underwent apoptosis during ejection from the monolayer. Apoptotic bodies were never seen in the monolayer but morphologically normal cells that were positive for M30 or cleaved caspase-3 were often seen. ZO-1 protein was usually (41/42) localized to the apical pole of cells neighboring a shedding event. Phosphorylated MLCs could be identified in 50% of shedding events. In conclusion, cell shedding is associated with apoptosis though it remains unclear whether apoptosis initiates shedding. It is also associated with phosphorylation of MLCs; a process associated previously with wound healing.
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PMID:Characterization of epithelial cell shedding from human small intestine. 1690 28

Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160+/-20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172+/-25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.
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PMID:Octreotide promotes apoptosis in human somatotroph tumor cells by activating somatostatin receptor type 2. 1695 43

Ex situ culture of human gestational tissues has been routinely used as a model to investigate tissue function. The objective of this study was to determine the effect of varying oxygen concentrations on human term placental explants over a 24-h time period. Specifically, the effect of incubating placental explants in oxygen concentrations of 8%, 21% or 95% on tissue viability, metabolism and cell death was measured by assessing glucose consumption, lactate production, release of lactate dehydrogenase, parathyroid hormone-related protein (PTHrP), tumour necrosis factor-alpha (TNF-alpha) and 8-isoprostane, immunoreactivity for cleaved-caspase-9 and immunohistochemistry for the caspase-3-cleaved cytokeratin-18 neoepitope, M30. Exposure to higher oxygen concentrations significantly increased the rates of glucose consumption and lactate production. Apoptosis was significantly increased under conditions of higher oxygen as evidenced by increased M30 in placental explant sections. Similarly, hyperoxia significantly increased the releases of PTHrP, TNF-alpha and 8-isoprostane. Thus, incubation of placental explants with oxygen concentrations of 95% and, to a lesser extent, 21% oxygen was associated with the modulation of multiple cellular response pathways including those associated with tissue viability and cell death. These data are consistent with the hypothesis that hyperoxia activates pathways and mechanisms involved in cellular metabolism, necrosis and apoptosis, thereby shifting the balance from a steady state towards cell death.
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PMID:Effect of high oxygen on placental function in short-term explant cultures. 1731 88

Gut epithelial apoptosis is involved in the pathophysiology of multiple diseases. This study characterized intestinal apoptosis in three mechanistically distinct injuries with different kinetics of cell death. FVB/N mice were subjected to gamma radiation, Pseudomonas aeruginosa pneumonia or injection of monoclonal anti-CD3 antibody and sacrificed 4, 12, or 24 hours post-injury (n=10/time point). Apoptosis was quantified in the jejunum by hematoxylin and eosin (H&E), active caspase-3, terminal deoxynucleotidyl transferase dUTP-mediated nick end labeling (TUNEL), in situ oligoligation reaction (ISOL,) cytokeratin 18, and annexin V staining. Reproducible results were obtained only for H&E, active caspase-3, TUNEL and ISOL, which were quantified and compared against each other for each injury at each time point. Kinetics of injury were different with early apoptosis highest following radiation, late apoptosis highest following anti CD3, and more consistent levels following pneumonia. ISOL was the most consistent stain and was always statistically indistinguishable from at least 2 stains. In contrast, active caspase-3 demonstrated lower levels of apoptosis, while the TUNEL assay had higher levels of apoptosis in the most severely injured intestine regardless of mechanism of injury. H&E was a statistical outlier more commonly than any other stain. This suggests that regardless of mechanism or kinetics of injury, ISOL correlates to other quantification methods of detecting gut epithelial apoptosis more than any other method studied and compares favorably to other commonly accepted techniques of quantifying apoptosis in a large intestinal cross sectional by balancing sensitivity and specificity across a range of times and levels of death.
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PMID:Epithelial apoptosis in mechanistically distinct methods of injury in the murine small intestine. 1735 92

Hepatocyte apoptosis is an important feature of liver injury in hepatitis C virus (HCV) infection. However, the mechanism of apoptosis and consequences on disease progression in vivo have not been investigated fully in part due to the lack of adequate small animal models. In this study, transgenic (tg) mice were produced that express conditionally HCV structural proteins (core, E1, E2 and p7) in the liver following Cre-mediated DNA recombination. Using a novel Cre-estrogen receptor fusion protein (Cre-ER) induction strategy, tamoxifen was injected intraperitoneally (i.p.), which induced Cre nuclear translocation, transgene recombination and HCV protein expression in the liver. Hepatic expression of HCV core and envelope proteins resulted in increased hepatocyte apoptosis, detected by the TUNEL assay, between 7 and 33 days after induction. These results were confirmed by the presence of increased levels of apoptosis-associated cytokeratin 18 (CK-18) in the sera of the same animals. The presence of cleaved caspase-3 and elevated levels of CHOP/GADD153 in the liver suggests an endoplasmic reticulum (ER) stress-associated apoptosis mechanism. This study suggests an in vivo correlation between HCV structural protein expression, ER stress and hepatocyte apoptosis, implicating a potentially important mechanism of HCV pathogenesis.
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PMID:Cre-estrogen receptor-mediated hepatitis C virus structural protein expression in mice. 1762 8

M-30 and 4HNE adducts are two markers of active liver disease. M-30 is a serologic marker and 4HNE adducts are histologic markers. M-30 is a marker for apoptosis because it is a fragment of cytokeratin-18 left over from proteolysis by caspase 3. 4HNE is a marker of oxidative stress because it results from lipid peroxidation. Both markers are commonly found in nonalcoholic steatohepatitis and in alcoholic hepatitis. Liver biopsies from patients with steatohepatitis, 11 alcoholic and 11 non-alcoholics were stained for 4HNE and M-30. Almost all of the biopsies in both groups showed 4HNE- and M-30-positive aggresomes in hepatocytes. Mallory Denk bodies (MDB) stained variably positive for M-30, whereas 4HNE was present in aggresomes independent of MDBs. However, they were sometimes located in hepatocytes which also contained MDBs as shown by confocal microscopy of double stained biopsies. The results indicate that the formation of M-30 and 4HNE aggresomes occurs through different pathways of liver cell injury in both types of steatohepatitis.
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PMID:M-30 and 4HNE are sequestered in different aggresomes in the same hepatocytes. 1796 45


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