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)

We investigated whether retinal pigment epithelial (RPE) responds to ceramide, a known second messenger of apoptosis. RPE cells were isolated by 6-8 day old Long Evans rat eye. We used MTS assay for viability test, and used Hoechst 33552 and propidium iodide for apoptotic cell staining. In cultured rat RPE cells, the addition of membrane-permeable ceramide induced apoptosis-like cell death rapidly. RPE cell death was dependent on C2-ceramide concentration. The effective dose (ED50) of C2-ceramide was 23.64 microM. Ceramide-induced RPE cell death was inhibited by zVAD-fmk, a CPP32-like protease inhibitor. Our findings indicated that ceramide in RPE cell death functions upstream of CPP32-like proteases.
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PMID:Ceramide-induced cell death in cultured rat retinal pigment epithelial cells. 1077 6

Copper toxicity contributes to neuronal death in Wilson's disease and has been speculatively linked to the pathogenesis of Alzheimer's and prion diseases. We examined copper-induced neuronal death with the goal of developing neuroprotective strategies. Copper catalyzed an increase in hydroxyl radical generation in solution, and the addition of 20 microM copper for 22 hours to murine neocortical cell cultures induced a decrease in ATP levels and neuronal death without glial death. This selective neuronal death was associated with activation of caspase-3 and was reduced by free radical scavengers and Z-Val-Ala-Asp fluoromethylketone, consistent with free radical-mediated injury leading to apoptosis. Pyruvate dehydrogenase is especially vulnerable to inhibition by oxygen free radicals, and the upstream metabolites, pyruvate, phosphoenolpyruvate, and 2-phosphoglycerate were elevated in cortical cells after toxic exposure to copper. One approach to protecting pyruvate dehydrogenase from oxidative attack might be to enhance binding to cofactors. Addition of thiamine, dihydrolipoic acid, or pyruvate reduced copper-induced neuronal death. To test efficacy in vivo, we added 1% thiamine to the drinking water of Long Evans Cinnamon rats, an animal model of Wilson's disease. This thiamine therapy markedly extended life span from 6.0 +/- 1.6 months to greater than 16 months.
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PMID:Cofactors of mitochondrial enzymes attenuate copper-induced death in vitro and in vivo. 1221 Jul 90

Excess release of chelatable zinc (Zn(2+)) from central synaptic vesicles may contribute to the pathogenesis of selective neuronal cell death following transient forebrain ischemia, but a role in neurodegeneration after focal ischemia has not been defined. Adult male Long-Evans rats subjected to middle cerebral artery occlusion (MCAO) for 30 min followed by reperfusion developed delayed cerebral infarction reaching completion 3 days after the insult. One day after the insult, many degenerating cerebral neurons exhibited increased intracellular Zn(2+), and some labeled with the antibody against activated caspase-3. I.c.v. administration of the Zn(2+) chelator, EDTA saturated with equimolar Ca(2+) (CaEDTA), 15 min prior to ischemia attenuated subsequent Zn(2+) translocation into cortical neurons, and reduced infarct volume measured 3 days after ischemia. Although the protective effect of CaEDTA at this endpoint was substantial (about 70% infarct reduction), it was lost when insult severity was increased (from 30 to 60 min MCAO), or when infarct volume was measured at a much later time point (14 days instead of 3 days after ischemia). These data suggest that toxic Zn(2+) translocation, from presynaptic terminals to post-synaptic cell bodies, may accelerate the development of cerebral infarction following mild transient focal ischemia.
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PMID:Zinc translocation accelerates infarction after mild transient focal ischemia. 1243 25

Erectile dysfunction (ED) is commonly experienced in men with diabetes mellitus. Vascular endothelial growth factor (VEGF) has been extensively documented for its pathogenic significance in different complications of diabetes. We hypothesized that expressions of VEGF, its receptors and its signaling pathway Akt may be drastically altered in diabetic penile tIssues and their alterations may modulate penile expression of the molecules that are believed to play a role in diabetic ED. Otsuka Long-Evans Fatty (OLETF) rats, a type II (non-insulin-dependent) diabetes mellitus, were used at the insulin-resistant stage of type II diabetes (20 weeks of age). We determined protein and mRNA expressions of VEGF, its receptors, Akt, nitric oxide synthase isoforms, and apoptosis-related molecules in the penis using immunohistochemistry, Western blotting, in situ hybridization, and real-time quantitative PCR analyses. The penile sections were also submitted to the Tdt-mediated dUTP nick end labeling assay for apoptosis. OLETF rats showed marked reductions in penile expression of VEGF, its two receptors and Akt. In OLETF rat penises, endothelial and neuronal nitric oxide synthase isoforms were expressed less abundantly. Furthermore, while anti-apoptotic markers, Bcl-2 and phosphorylated Bad, were down-regulated, pro-apoptotic markers, active caspase-3 and Bax, were up-regulated, resulting in the appearance of apoptotic cells in the penile tIssues of OLETF rats. The VEGF signaling system would work less well in diabetic penile tIssues as a result of the reduced expression, leading to diminished endothelial production of nitric oxide and apoptosis-related erectile tIssue damage. We propose that the abnormalities of the VEGF signaling system in the penis may play a role in the pathophysiology of diabetic ED.
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PMID:Diminished penile expression of vascular endothelial growth factor and its receptors at the insulin-resistant stage of a type II diabetic rat model: a possible cause for erectile dysfunction in diabetes. 1466 2

Experimental models of traumatic brain injury have been developed to replicate selected aspects of human head injury, such as contusion, concussion, and/or diffuse axonal injury. Although diffuse axonal injury is a major feature of clinical head injury, relatively few experimental models of diffuse traumatic brain injury (TBI) have been developed, particularly in smaller animals such as rodents. Here, we describe the pathophysiological consequences of moderate diffuse TBI in rats generated by a newly developed, highly controlled, and reproducible model. This model of TBI caused brain edema beginning 20 min after injury and peaking at 24 h post-trauma, as shown by wet weight/dry weight ratios and diffusion-weighted magnetic resonance imaging. Increased permeability of the blood-brain barrier was present up to 4 h post-injury as evaluated using Evans blue dye. Phosphorus magnetic resonance spectroscopy showed significant declines in brain-free magnesium concentration and reduced cytosolic phosphorylation potential at 4 h post-injury. Diffuse axonal damage was demonstrated using manganese-enhanced magnetic resonance imaging, and intracerebral injection of a fluorescent vital dye (Fluoro-Ruby) at 24-h and 7-day post-injury. Morphological evidence of apoptosis and caspase-3 activation were also found in the cerebral hemisphere and brainstem at 24 h after trauma. These results show that this model is capable of reproducing major biochemical and neurological changes of diffuse clinical TBI.
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PMID:The pathobiology of moderate diffuse traumatic brain injury as identified using a new experimental model of injury in rats. 1535 Sep 63

The objective of this study was to evaluate the potential role of TNF-alpha in the onset of acute hepatitis in the Long-Evans Cinnamon (LEC) rat, an animal model for inherited copper (Cu) toxicosis. In LEC rats, Cu is accumulated in the liver with age, and clinical signs of acute hepatitis were observed as, icterus, reduced body weight, nasal bleeding, dehydration, and reduced food intake at 12 weeks of age. Cellular changes such as apoptosis in the liver were evident in these rats with increasing age. Positive TNF-alpha and TNFR1 immunostainings were observed in hepatocytes and Kupffer cells in LEC rats. Hepatic levels of caspase-3 activity, TNF-alpha mRNA, and protein were also increased in LEC rats from 6 to 12 weeks of age as compared with control Long-Evans (LE) rats. The neutralization of TNF-alpha by passive immunization or the inhibition of caspase activity can block the apoptotic process initiated by TNF-alpha. In this study, we evaluated the effects of passive immunization of LEC rats with weekly administration of anti-rat TNF-alpha on Cu-induced acute hepatitis. This treatment resulted in a reduction of the percentage of apoptotic cells in the liver, decreased activity of caspase-3, and also in down-regulation of the TNF-alpha gene expression. Thus, these results suggest a major role for TNF-alpha on the pathogenesis of Cu-induced acute hepatitis in LEC rats.
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PMID:Role of tumor necrosis factor-alpha in the development of spontaneous hepatic toxicity in Long-Evans Cinnamon rats. 1547 65

Wilson's disease (WD) is an inherited disorder, characterized by selective copper deposition in liver and brain, chronic hepatitis and extra-pyramidal signs. In this study, we investigated changes of biochemical markers of oxidative stress and apoptosis in liver, striatum and cerebral cortex homogenates from Long-Evans Cinnamon (LEC) rats, a mutant strain isolated from Long Evans (LE) rats, in whom spontaneous hepatitis develops shortly after birth. LEC and control (LE) rats at 11 and 14 weeks of age were used. We determined tissue levels of glutathione (GSH/GSSG ratio), lipid peroxides, protein-thiols (P-SH), nitric oxide metabolites, activities of caspase-3 and total superoxide-dismutase (SOD), striatal levels of monoamines and serum levels of hepatic amino-transferases. We observed a decrease of protein-thiols, GSH/GSSG ratio and nitrogen species associated to increased lipid peroxidation in the liver and striatum - but not in the cerebral cortex - of LEC rats, accompanied by dramatic increase in serum amino-transferases and decrease of striatal catecholamines. Conversely, SOD and caspase-3 activity increased consistently only in the cortex of LEC rats. Hence, we assume that enhanced oxidative stress may play a central role in the cell degeneration in WD, at the main sites of copper deposition, with discrete pro-apoptotic conditions developing in distal areas.
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PMID:Oxidative stress and pro-apoptotic conditions in a rodent model of Wilson's disease. 1608 Dec 51

We have previously shown that dietary red palm oil (RPO) supplementation improves functional recovery in hearts subjected to ischaemia-reperfusion. However, little knowledge exists concerning the effects of RPO supplementation of a high-cholesterol diet on ischaemia-reperfusion injury. The signalling mechanisms responsible for RPO's effects in the presence of cholesterol also remain to be elucidated. Therefore, the aim of the present study was to examine the effects of RPO, given with a high-cholesterol diet, on mitogen-activated protein kinase (MAPK) phosphorylation and apoptosis. Long-Evans rats were fed a control diet, a control diet containing 2% cholesterol, or a control diet containing 2% cholesterol and 7 g RPO per kg (CRPO) for 5 weeks. Hearts were excised and mounted on an isolated working heart perfusion apparatus. Cardiac function was measured after which hearts were freeze-clamped and used to assess MAPK phosphorylation and to evaluate apoptosis. Cholesterol supplementation caused a poor aortic output (AO) recovery compared with the control group (35.5 (sem 6.2) v. 55.4 (sem 2.5) %), but when RPO was added, the percentage AO increased significantly. The cholesterol group's poor AO was associated with a significant increase in p38-MAPK phosphorylation, whereas the CRPO-supplemented group showed as significant reduction in p38-MAPK phosphorylation when compared with the cholesterol-supplemented group. This significant reduction in p38-MAPK was also associated with reduced apoptosis as indicated by significant reductions in caspase-3 and poly(ADP-ribose) polymerase cleavage.
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PMID:Dietary red palm oil reduces ischaemia-reperfusion injury in rats fed a hypercholesterolaemic diet. 1734 77

The c-Jun N-terminal kinase (JNK) is induced by cerebral ischemia and injurious blood components acutely after subarachnoid hemorrhage (SAH). We hypothesized that inhibition of JNK will prevent damage to the neurovascular unit in the early brain injury period after SAH. Ninety-nine male SD rats (300-350 g) were randomly assigned to sham, SAH, and SAH treated with JNK inhibitor groups. SAH was induced by endovascular perforation. The JNK inhibitor SP600125 was administered intraperitoneally at 1 hr before and 6 hr after SAH. At 24 hr after SAH, we observed increased phosphorylation of JNK and c-Jun. Signs of neurovascular damage were observed in the hemorrhagic brains; these included the increases of aquaporin (AQP)-1 expression and brain water content as well as enhanced matrix metalloproteinase (MMP)-9 activity, vascular collagen IV loss, increased VEGF tissue level, and Evans blue extravasation. The appearances of cleaved caspase-3 expression, TUNEL-positive cells, and apoptotic morphology in cerebral tissues were associated with neurological deficit after SAH. JNK inhibition prevented c-Jun phosphorylation and suppressed AQP1, MMP-9, VEGF, and caspase-3 activation, with concomitant diminution of neuronal injury, blood-brain barrier preservation, reduced brain swelling, and improved neurological deficit in rats after SAH. This study demonstrates a multitude of beneficial effects of JNK inhibition, including protection of the neurovascular unit in early brain injury after SAH.
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PMID:Role of c-Jun N-terminal kinase in early brain injury after subarachnoid hemorrhage. 1741 Jun

Although enteric glial cells (EGCs) have been demonstrated to play a key role in maintaining intestinal epithelial barrier integrity, it is not known how EGCs regulate this integrity. We therefore hypothesized that glial-derived neurotrophic factor (GDNF) produced by EGCs might be involved in this regulation. Here we investigated the role of GDNF in regulating epithelial barrier function in vivo. Recombinant adenoviral vectors encoding GDNF (Ad-GDNF) were administered intracolonically in experimental colitis induced by dextran sulphate sodium (DSS). The disease activity index (DAI) and histological score were measured. Epithelial permeability was assayed using Evans blue dye. The anti-apoptotic potency of GDNF in vivo was evaluated. The expression of tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and myeloperoxidase (MPO) activity were measured by ELISA assay and/or RT-PCR. The expression of ZO-1, Akt, caspase-3, and NF-kappaB p65 was analysed by western blot assay. Our results showed that GDNF resulted in a significant reduction in enhanced permeability, inhibited MPO activity, IL-1beta and TNF-alpha expression, and increased ZO-1 and Akt expression. Moreover, GDNF strongly prevented apoptosis in vivo and significantly ameliorated experimental colitis. Our findings indicate that GDNF participates directly in restoring epithelial barrier function in vivo via reduction of increased epithelial permeability and inhibition of mucosal inflammatory response, and is efficacious in DSS-induced colitis. These findings support the notion that EGCs are able to regulate intestinal epithelial barrier integrity indirectly via their release of GDNF in vivo. GDNF is namely an important mediator of the cross-talk between EGCs and mucosal epithelial cells. GDNF may be a useful therapeutic approach to the treatment of inflammatory bowel disease.
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PMID:Glial-derived neurotrophic factor regulates intestinal epithelial barrier function and inflammation and is therapeutic for murine colitis. 2063 86


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