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

We hypothesized that the hepatotoxicity that develops after the induction of oxidative stress (induced by d-galactosamine [GalN]) can be ameliorated by alpha-tocopherol (ATC) and the soy isoflavone daidzein. To test this, we ranked and assigned male Wistar rats into 6 groups, which involved pretreatment (ATC or daidzein) for 1 hour followed by treatment (GalN) for 23 hours. Histopathologic analysis showed that GalN administration induced marked necrosis (P < .001), steatosis (P < .001), both lobular and portal inflammations (P < .001), overall histopathologic score (P < .001), and activation of caspase-3 in the liver (P < .001). Immunohistochemical staining of malondialdehyde-protein adducts, a measure of oxidative stress, was increased in response to GalN (P < .001). Paradoxically, there were increases in total (P < .05) and cytosolic superoxide dismutase (P < .001) activities after GalN administration, indicative of an up-regulation of antioxidant defenses. The concentration of total protein (P < .001), albumin (P < .01), and globulin fractions (P < .001) in the plasma, as well as the activity of aspartate aminotransferase (P < .001), was significantly perturbed after GalN treatment, reflective of overall acute hepatic injury. Administration of daidzein showed a significant amelioration of the Ga1N-induced increase in malondialdehyde-protein adducts (P < .01) and cytosolic superoxide dismutase activities (P < .01) in the liver. However, all other variables were not significantly altered in response to daidzein. In response to ATC pretreatment, the total histopathologic score (P < .05), degree of necrosis (P < .05), and both lobular (P < .05) and portal (P = .05) inflammations were significantly ameliorated. To conclude, both daidzein and ATC protect the liver against oxidative damage possibly via different pathways.
 ...
PMID:The cytoprotective effect of alpha-tocopherol and daidzein against d-galactosamine-induced oxidative damage in the rat liver. 1757 Feb 44

Plasma from patients with liver failure may contain toxic molecules that cause hepatocyte apoptosis and worsen liver disease, suggesting that removal of pro-apoptotic factors is an appropriate therapeutic strategy. We investigated the apoptosis of human hepatocytes induced by plasma from patients with both acute and acute-on-chronic liver disease, and the effect of molecular adsorbent dialysis (molecular adsorbent recirculation system [MARS] dialysis) on this. Apoptotic effects of acute and acute-on-chronic liver failure plasmas from 46 patients were assessed on cultured primary human hepatocytes using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) labeling and caspase 3 activation. In 11 patients undergoing MARS dialysis, the pro-apoptotic effect of their plasma was analyzed before and after therapy. Acute liver failure plasma induced more apoptosis than normal plasma (within 4-6 h of culture, a 2.5-fold increase by TUNEL labeling, 1.8-fold by caspase 3 activation), via a pathway involving caspase 8, suggesting involvement of the death-receptor pathway. However, not all acute liver failure plasmas were significantly more pro-apoptotic than normal plasma. Plasma from patients with acutely decompensated chronic liver disease induced apoptosis at the same rate as normal plasma. MARS dialysis improved biochemical parameters indicating effective removal of albumin-bound molecules, but the apoptotic effects of the plasma were unchanged. Thus, plasma of patients with acute liver failure, compared to normal plasma, induced increased apoptosis of primary human hepatocytes by a caspase-8- and caspase-3-dependent pathway. The apoptosis induced in the presence of liver failure plasma was not reduced by MARS dialysis.
 ...
PMID:Characterization of pro-apoptotic effect of liver failure plasma on primary human hepatocytes and its modulation by molecular adsorbent recirculation system therapy. 1772 1

The present study was aimed at clarifying the effects of an anti-apoptotic protein for modulating symptoms in acute lung injury (ALI). From Bcl-x(L), a Bcl-2 family member, we constructed an artificial protein (FNK) and fused it with the protein transduction domain (PTD) of the HIV/Tat protein (PTD-FNK) to facilitate its permeation into cells. ALI was induced by intratracheal infusion of lipopolysaccharide (LPS) into Sprague-Dawley male rats. PTD-FNK was injected into the peritoneal cavity of the animals either 2 h before, or 3 h or 6 h after LPS challenge. All rats were sacrificed 24 h after the last treatment. Cell differential ratios and albumin concentration were estimated in bronchoalveolar lavage fluid. We examined histological change, myeloperoxidase activity, TUNEL assay, caspase-3/caspase-3-like activity and immunohistochemical reaction for caspase 3 (active form). In animals with PTD-FNK treatment, the albumin leakage was significantly attenuated with protection of tissue damage. Also, the apoptosis of alveolar wall cells was reduced by PTD-FNK treatment, while a total cell number and the neutrophil ratio were not changed. Human umbilical vein endothelial cells (HUVEC) and cells of an alveolar epithelial cell line (A549) were exposed to LPS or TNF-alpha with or without PTD-FNK treatment in vitro. Cell survival rates examined by trypan-blue exclusion assay were increased by PTD-FNK treatment in a concentration-dependent manner. Thus, PTD-FNK could play a protective role in ALI by suppressing apoptosis of alveolar epithelial cells and capillary endothelial cells despite of some effect on neutrophil activity.
 ...
PMID:Anti-apoptotic PTD-FNK protein suppresses lipopolysaccharide-induced acute lung injury in rats. 1795 70

Advanced glycation endproducts (AGEs) are implicated in the complications of diabetes and ageing, affecting several tissues, including bone. Metformin, an insulin-sensitizer drug, reduces the risk of life-threatening macrovascular complications. We have evaluated the hypothesis that metformin can abrogate AGE-induced deleterious effects in osteoblastic cells in culture. In two osteoblast-like cell lines (UMR106 and MC3T3E1), AGE-modified albumin induced cell death, caspase-3 activity, altered intracellular oxidative stress and inhibited alkaline phosphatase activity. Metformin-treatment of osteoblastic cells prevented these AGE-induced alterations. We also assessed the expression of AGE receptors as a possible mechanism by which metformin could modulate the action of AGEs. AGEs-treatment of osteoblast-like cells enhanced RAGE protein expression, and this up-regulation was prevented in the presence of metformin. Although the precise mechanisms involved in metformin signaling are still elusive, our data implicate the AGE-RAGE interaction in the modulation of growth and differentiation of osteoblastic cells.
 ...
PMID:Metformin reverts deleterious effects of advanced glycation end-products (AGEs) on osteoblastic cells. 1827 53

Cardiolipin (CL) is a major mitochondrial membrane phospholipid in the mammalian heart and the remodeling of CL is essential to maintain its unique unsaturated fatty acyl composition. We examined CL de novo biosynthesis and remodeling in the surviving population of H9c2 cardiac myoblast cells exposed to 2-deoxyglucose (2-DG). H9c2 cells were incubated in the absence or presence of 2-DG for 16 h with [1,3-3H]glycerol or [1-14C]linoleic acid (bound to albumin in a 1:1 molar ratio). Dead cells were removed and radioactivity was incorporated into CL. Its pool size, fatty acid composition, and the activities of the CL biosynthesis and remodeling enzymes were determined. The CL pool size, its fatty acid composition, and [1,3-3H]glycerol or [1-14C]linoleic acid incorporated into CL were unaltered in the surviving population of 2-DG-treated cells compared with controls. In addition, the activities of the CL de novo biosynthetic enzymes were unaltered. Cleaved caspase-3 and poly(ADP-ribose) polymerase were slightly elevated in the surviving population of 2-DG-treated cells compared with controls, indicating that apoptosis induction was occurring in these cells. Mitochondrial phospholipase A2 and monolysocardiolipin acyltransferase (MLCL AT) activities increased 33% (p < 0.05) and 63% (p < 0.05), respectively, in 2-deoxyglucose-treated cells compared with controls. In contrast, the activity of ALCAT1, an endoplasmic reticulum MLCL AT, decreased 77% (p < 0.05), but this was not due to a reduction in ALCAT1 mRNA expression. The mRNA expression of the Barth syndrome gene TAZ, encoding a mitochondrial CL transacylase, was unaltered in 2-DG treated cells. The increase in mitochondrial MLCL AT activity was due to an elevated expression in MLCL AT protein. Thus, an increase in MLCL AT activity and expression occurs to maintain the CL pool in the surviving population of H9c2 cells as a compensatory mechanism for the elevated phospholipase A2 activity seen in 2-DG-induced apoptosis. We hypothesize that increased mitochondrial MLCL AT activity and its expression, and hence, elevated CL resynthesis, may be a protective mechanism against monolysocardiolipin-mediated apoptosis.
 ...
PMID:Mitochondrial monolysocardiolipin acyltransferase is elevated in the surviving population of H9c2 cardiac myoblast cells exposed to 2-deoxyglucose-induced apoptosis. 1836 41

Toxic effects of the mycotoxin deoxynivalenol (DON) observed in animals range from diarrhea, vomiting, gastro-intestinal inflammation to necrosis of several tissues. In the last years, DON has been tested in hepatocytes of several animal species for its cytotoxicity. However, these tests are limited to the use of animal cells. No studies using human hepatocytes are available. Further investigations with the human hepatocellular liver carcinoma cell line HepG2 might be limited due to the disadvantages of cell lines (e. g. immortalization, tumor derivation, longtime cultivation) and do not necessarily reflect the response of normal human cells. In order to overcome this problem and to be closer to the human situation, we studied the effect of DON in human primary hepatocytes and compared these data to the effects in the HepG2 cell line. Cell viability, apoptotic and necrotic cell death, albumin secretion and metabolic activity were determined. It could be demonstrated that DON has a distinct cytotoxic effect on human primary hepatocytes. Viability, protein content and albumin secretion were reduced in a dose-dependent manner. The apoptotic key enzyme caspase-3 was activated, while LDH release occurred only after long incubation time due to a secondary necrosis. Furthermore, we studied the metabolism of DON using LC-MS/MS. DON was neither metabolized by primary hepatocytes cells nor by the HepG2 cell line.
 ...
PMID:Effects of the mycotoxin deoxynivalenol on human primary hepatocytes. 1861 82

Advanced glycation end products (AGEs) accumulate during aging and to higher extents under pathological conditions such as diabetes. Since we previously showed that mast cells expressed the AGE-binding protein, receptor for AGEs (RAGE) on their cell surface, we examined whether AGE affected mast cell survival. Herein, we demonstrate that mast cells undergo apoptosis in response to AGE. Glycated albumin (GA), an AGE, but not stimulation with the high-affinity IgE receptor (FcepsilonRI), can induce mast cell death, as measured by annexin V/propidium iodide double-staining. GA (> or =0.1 mg/ml) exhibited this pro-apoptotic activity in a concentration-dependent manner. GA and FcepsilonRI stimulation increased the cytosolic Ca(2+) levels to a similar extent, whereas GA, but not FcepsilonRI stimulation, caused mitochondrial Ca(2+) overload and membrane potential collapse, resulting in mitochondrial integrity disruption, cytochrome c release and caspase-3/7 activation. In addition, GA, but not FcepsilonRI stimulation, induced extracellular release of superoxide from mitochondria, and this release played a key role in the disruption of Ca(2+) homeostasis. Knockdown of RAGE expression using small interfering RNA abolished GA-induced apoptosis, mitochondrial Ca(2+) overload, and superoxide release, demonstrating that RAGE mediates the GA-induced mitochondrial death pathway. AGE-induced mast cell apoptosis may contribute to the immunocompromised and inflammatory conditions.
 ...
PMID:Extracellular superoxide released from mitochondria mediates mast cell death by advanced glycation end products. 1882 20

Bacterial LPS (endotoxin) is implicated in the pathogenesis of acute liver failure and several chronic inflammatory liver diseases. To evaluate the effect of hepatocyte cyclooxygenase (COX)-2 in LPS-induced liver injury, we generated transgenic mice with targeted expression of COX-2 in the liver by using the albumin promoter-enhancer driven vector and the animals produced were subjected to a standard experimental protocol of LPS-induced acute fulminant hepatic failure (i.p. injection of low dose of LPS in combination with d-galactosamine (d-GalN)). The COX-2 transgenic mice exhibited earlier mortality, higher serum aspartate aminotransferase and alanine aminotransferase levels and more prominent liver tissue damage (parenchymal hemorrhage, neutrophilic inflammation, hepatocyte apoptosis, and necrosis) than wild-type mice. Western blot analysis of the liver tissues showed that LPS/d-GalN treatment for 4 h induced much higher cleavage of poly(ADP-ribose) polymerase, caspase-3, and caspase-9 in COX-2 transgenic mice than in wild-type mice. Increased hepatic expression of JNK-2 in COX-2 transgenic mice suggest that up-regulation of JNK-2 may represent a potential mechanism for COX-2-mediated exacerbation of liver injury. Blocking the prostaglandin receptor, EP(1), prevented LPS/d-GalN-induced liver injury and hepatocyte apoptosis in COX-2 transgenic mice. Accordingly, the mice with genetic ablation of EP(1) showed less LPS/d-GalN-induced liver damage and less hepatocyte apoptosis with prolonged survival when compared with the wild-type mice. These findings demonstrate that COX-2 and its downstream prostaglandin receptor EP(1) signaling pathway accelerates LPS-induced liver injury. Therefore, blocking COX-2-EP(1) pathway may represent a potential approach for amelioration of LPS-induced liver injury.
 ...
PMID:Transgenic expression of cyclooxygenase-2 in hepatocytes accelerates endotoxin-induced acute liver failure. 1901 95

Premature infants are at risk for bilirubin-associated brain damage. In cell cultures bilirubin causes neuronal apoptosis and necrosis. Ibuprofen is used to close the ductus arteriosus, and is often given when hyperbilirubinemia is at its maximum. Ibuprofen is known to interfere with bilirubin-albumin binding. We hypothesized that bilirubin toxicity to cultured rat embryonic cortical neurons is augmented by coincubation with ibuprofen. Incubation with ibuprofen above a concentration of 125 microg/mL reduced cell viability, measured by methylthiazole tetrazolium reduction, to 68% of controls (p < 0.05). Lactate dehydrogenase (LDH) release increased from 29 to 38% (p < 0.01). The vehicle solution did not affect cell viability. Coincubation with 10 microM unconjugated bilirubin (UCB)/human serum albumin in a molar ratio of 3:1 and 250 microg/mL ibuprofen caused additional loss of cell viability and increased LDH release (p < 0.01), DNA fragmentation, and activated caspase-3. Preincubation with the pan-caspase inhibitor z-val-ala-asp-fluoromethyl ketone abolished ibuprofen- and UCB-induced DNA fragmentation. The study demonstrates that bilirubin in low concentration of 10 microM reduces neuron viability and ibuprofen increases this effect. Apoptosis is the underlying cell death mechanism.
 ...
PMID:Ibuprofen augments bilirubin toxicity in rat cortical neuronal culture. 1912 20

Hepatic apoptosis is elevated in patients with non-alcoholic steatohepatitis and is correlated with the severity of the disease. Long-chain saturated fatty acids, such as palmitate, induce apoptosis in liver cells. The present study examined adiponectin-mediated protection against saturated fatty acid-induced apoptosis in the human hepatoma cell line, HepG2. Cells were cultured in a control media (i.e. without fatty acids) or the same media containing 250 micromol L(-1) of albumin-bound oleate or palmitate for 24 h. The adiponectin concentrations used were: 0, 1, 10 or 100 microg mL(-1) (n = 4-6 per treatment). Palmitate and thapsigargin, but not oleate, activated caspase-3 and decreased cell viability in the absence of adiponectin. Adiponectin reduced palmitate- and thapsigargin-induced activation of caspase-3 and cell death in a dose-dependent manner. Phosphatidylinositol 3-kinase and AMP-activated protein kinase inhibitors abolished the effects of adiponectin. Adiponectin-induced inhibition of palmitate- and thapsigargin-induced apoptosis was not the result of an augmentation in the unfolded protein response or the increased expression of genes encoding the inhibitor of apoptosis proteins, inhibitor of apoptosis protein-2 and X-linked mammalian inhibitor of apoptosis protein. Palmitate and thapsigargin, but not oleate, increased c-Jun NH(2) terminal kinase phosphorylation in the absence of adiponectin. Adiponectin blocked palmitate- and thapsigargin-induced activation of c-Jun NH(2) terminal kinase and reduced apoptosis. These data suggest that adiponectin is an important determinant of saturated fatty acid-induced apoptosis in liver cells and may have implications for fatty acid-mediated liver cell injury in adiponectin-deficient individuals.
 ...
PMID:Full-length adiponectin protects hepatocytes from palmitate-induced apoptosis via inhibition of c-Jun NH2 terminal kinase. 1929 Aug 87


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>