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)

Previous studies have shown that cerebral hypoxia results in increased activity of caspase-9, a key initiator of programmed cell death. We have also shown increased nitric oxide (NO) free radical generation during hypoxia in the cerebral cortex of newborn piglets. The present study tests the hypothesis that hypoxia-induced increase in caspase-9 activity in the cerebral cortex of newborn piglets is mediated by NO derived from neuronal nitric oxide synthase (nNOS). To test this hypothesis, cytosolic caspase-9 activity was determined in 15 newborn piglets divided into three groups: normoxic (Nx, n=5), hypoxic (Hx, n=5), and Hx pretreated with 7-nitroindazole sodium salt (7-NINA), a selective nNOS inhibitor, 1mg/kg, i.p., 1h prior to hypoxia (Hx+7NI, n=5). The hypoxic piglets were exposed to an FiO(2) of 0.06 for 1h. Tissue hypoxia was documented by ATP and phosphocreatinine (PCr) levels. The cytosolic fraction was obtained from the cerebral cortical tissue following centrifugation at 100,000 x g for 1h and caspase-9 activity was assayed using Ac-Leu-Glu-His-Asp-amino-4-methyl coumarin, a specific fluorogenic substrate for caspase-9. Caspase-9 activity was determined spectroflourometrically at 460 nm using 380 nm as excitation wavelength. ATP levels (micromol/g brain) were 4.35+/-0.21 in the Nx 1.43+/-0.28 in the Hx (p<0.05 versus Nx), and 1.73+/-0.33 in the Hx+7-NINA group (p<0.05 versus Nx, p=NS versus Hx). PCr levels (micromol/g brain) were 3.80+/-0.26 in the Nx, 0.96+/-0.20 in the Hx (p<0.05 versus Nx), and 1.09+/-0.39 in the Hx+7 NINA group (p<0.05 versus Nx, p=NS versus Hx). Cytosolic caspase-9 activity (nmol/mg protein/h), increased from 1.27+/-0.15 in the Nx to 2.13+/-0.14 in the Hx (p<0.05 versus Nx) compared to 1.10+/-0.21 in the Hx+7-NINA group (p<0.05 versus Hx, p=NS versus Nx). Caspase-3 activity (nmol/mg protein/h) also increased from 9.39+/-0.73 in Nx to 18.94+/-3.64 in Hx (p<0.05 versus Nx) compared to 8.04+/-1.05 in the Hx+7-NINA group (p<0.05 versus Hx, p=NS versus Nx). The data show that administration of 7-NINA, an nNOS inhibitor, prevented the hypoxia-induced increase in caspase-9 activity that leads to increase in caspase-3 activity. Since nNOS inhibition blocked the increase in caspase-9 activity during hypoxia, we conclude that hypoxia-induced increase in caspase-9 activity is mediated by nNOS derived NO. We propose that the NO generated during hypoxia leads to activation of caspase-9 and results in initiation of caspase-cascade-dependent hypoxic neuronal death.
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PMID:Effect of neuronal nitric oxide synthase inhibition on caspase-9 activity during hypoxia in the cerebral cortex of newborn piglets. 1654 6

Work on acute models of cortical injury has revealed a population of small GABAergic interneurons that are induced to increase their low constitutive expression of neuronal nitric oxide (NO) synthase (nNOS). In some cases, this activation may play a role in NO-mediated degeneration of pyramidal neurons. In this report, we explore the anatomy of various classes of cortical nNOS (+) (nitrergic) neurons, with emphasis on small interneurons, in the medial temporal lobe of subjects with Alzheimer's disease (AD) from two well-characterized cohorts, the Baltimore Longitudinal Study on Aging (BLSA) and the Religious Order Study (ROS). We find that small calbindin (+) cortical interneurons are induced to high levels of NADPHd/nNOS reactivity early in AD and abound in areas with emerging neurofibrillary pathology, that is, in entorhinal cortex in the beginning of the limbic stage of Braak, in hippocampal CA1 in the mature limbic stage and in temporal neocortex in the late limbic stage. This pattern was robust and significant in the younger of the two AD cohorts studied (BLSA), but persisted as a trend in the older cohort (ROS). In optimally prepared material, we find a significant correlation between numbers of these interneurons and markers of neuronal cell death, for example, caspase-3 activation. Our results show that small cortical inhibitory interneurons represent an extensive signaling system that is induced to higher levels of NADPHd/nNOS expression early in the paralimbic-limbic-neocortical sequence of AD progression. We propose that nNOS/NO signaling initiated in these interneurons can serve as a marker of early cortical injury in AD. The specific role played by inhibitory interneurons and NO in the elaboration of specific neuropathologies associated with AD, that is, Abeta and neurofibrillary deposits and cell death deserves further exploration in experimental animal models.
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PMID:Early involvement of small inhibitory cortical interneurons in Alzheimer's disease. 1675 65

We have previously shown that the co-localization of neuronal nitric oxide synthase (nNOS) with neurofilament (NF) aggregates in motor neurons derived from transgenic mice over-expressing the human low molecular weight NF protein (hNFL+/+) is associated with a deregulation of calcium influx via the N-methyl-d-aspartate (NMDA) receptor, resulting in apoptosis. Because the absence of the GluR2 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoazolepropionic acid (AMPA) receptor confers calcium permeability and has been implicated in the process of excitotoxicity in ALS, we have examined the role of the AMPA receptor in this model. GluR2 protein expression and mRNA were examined in hNFL+/+ and wild-type motor neurons (wt). Live cell calcium imaging was performed using Oregon-Green Bapta and Fura-2 calcium dyes. For apoptotic studies, neurons were treated with glutamate, with or without glutamate receptor antagonists [6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) or (+)-5-methyl-10, 11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801)] and examined for active caspase-3 or phospholipid inversion. We observed that although both GluR2 mRNA and protein levels were decreased in hNFL+/+ motor neurons compared to wt, there was no appreciable calcium influx via the AMPA receptor. These studies demonstrate that calcium mediated excitotoxicity in NF aggregate-bearing neurons is NMDA receptor dependant.
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PMID:Calcium mediated excitotoxicity in neurofilament aggregate-bearing neurons in vitro is NMDA receptor dependant. 1736 87

Pyramidal relay neurons in limbic cortex are vulnerable to denervation lesions, i.e. pyramidal neurons in layer IIalpha of piriform cortex undergo transsynaptic apoptosis after lesions that interrupt their inputs from the olfactory bulb. We have previously established the role of inhibitory interneurons in elaborating signals that lead to the apoptosis of projection neurons in these lesion models, i.e. the upregulation of neuronal NOS and release of nitric oxide. Thus, we have proposed that cortical interneurons play an essential role in transducing injury to degenerative effects for nearby pyramidal neurons. In the present study, we extend the previous findings to a toxic model of degeneration of pyramidal neurons in the adult paralimbic cortex, i.e. after exposure to the NMDA channel blocker MK801. Our findings indicate that treatment of adult rats with MK801 in doses previously found to cause alterations in pyramidal neurons of the retrosplenial cortex (5mg/kg) results in an active caspase 3 (+), ultrastructurally apoptotic type of cell death involving the same projection neurons of layer IIalpha that are also vulnerable to bulbotomy lesions. Interneurons of layer I are induced by MK801 treatment to higher levels of nNOS expression and the selective nNOS inhibitor BRNI ameliorates pyramidal cell apoptosis caused by MK801. Our results indicate that certain pyramidal neurons in piriform cortex are very sensitive to NMDA blockade as they are to disconnection from modality-specific afferents and that inhibitory interneurons play significant roles in mediating various types of pro-apoptotic insults to cortical projection neurons via nNOS/NO signaling.
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PMID:NMDA inhibitors cause apoptosis of pyramidal neurons in mature piriform cortex: evidence for a nitric oxide-mediated effect involving inhibitory interneurons. 1744 67

3,4-Methylenedioxymethamphetamine (MDMA or "Ecstasy") is a psychoactive and hallucinogenic drug of abuse. MDMA has been shown to produce neurotoxicity both in animals and humans. MDMA and other amphetamines induce serotonergic and dopaminergic terminal neurotoxicity and also neurodegeneration in areas including the cortex, hippocampus, striatum and thalamus. Herein, we investigated the mechanisms involved in MDMA-induced neurotoxicity to neuronal serum free cultures from rat cortex. The hyperthermic effect produced by MDMA has been shown to be a clinically relevant aspect for the neurotoxic events. Thus, MDMA-induced toxicity to cortical neurons was evaluated both under normothermic (36.5 degrees C) and hyperthermic (40 degrees C) conditions. Our findings showed that MDMA produced neuronal apoptosis, accompanied by activation of caspase 3, in a concentration dependent manner. MDMA neurotoxicity was completely prevented by pre-treatment with a 5-HT(2A)-receptor antibody, which acted as an "irreversible non-competitive antagonist" of this receptor. Furthermore, MDMA depleted intracellular glutathione (GSH) levels in a concentration dependent manner, an effect that was attenuated by Ketanserin, a competitive 5-HT(2A)-receptor antagonist. Accordingly, N-acetylcysteine, an antioxidant and GSH precursor, also reduced MDMA-induced toxicity. Specific inhibitors of the inducible and neuronal nitric oxide synthase (NOS) partially prevented MDMA neurotoxicity, ascertaining the involvement of reactive nitrogen species, in the toxic effect. In conclusion, direct MDMA 5-HT(2A)-receptor stimulation produces intracellular oxidative stress that leads to neuronal apoptosis accompanied by caspase 3 activation.
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PMID:Ecstasy induces apoptosis via 5-HT(2A)-receptor stimulation in cortical neurons. 1757 1

Addition of bacterial lipopolysaccharides (LPS) and interferon-gamma (IFN-gamma) to rat astrocytes in primary culture promotes an early release of arachidonic acid (ARA) associated with an immediate inhibition of neuronal nitric oxide synthase (nNOS). Preventing the release of constitutive nitric oxide (NO) is indeed critical for activation of the nuclear factor kappa B, and for the expression of inducible nitric oxide synthase responsible for the formation of large amounts of NO. LPS/IFN-gamma also promotes an early release of superoxide, via activation of NADPH oxidase, but the generation of peroxynitrite (ONOO-) is prevented by the different timing of superoxide (minutes) and NO (hours) formation. Upstream inhibition of the ARA-dependent nNOS inhibitory signaling, however, caused the parallel release of superoxide and constitutive NO, thereby leading to formation of ONOO- levels triggering loss of ATP and mitochondrial membrane potential followed by the mitochondrial release of cytochrome c, activation of caspase 3 and morphological evidence of apoptosis. Nanomolar levels of exogenous ARA prevented all these events via inhibition of early ONOO- formation. Thus, the ARA-dependent nNOS inhibition observed in astrocytes exposed to pro-inflammatory stimuli, as LPS/IFN-gamma, is critical for both the expression of nuclear factor kappa B-dependent genes and for survival.
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PMID:Early release of arachidonic acid prevents an otherwise immediate formation of toxic levels of peroxynitrite in astrocytes stimulated with lipopolysaccharide/interferon-gamma. 1766 49

TP508 is a 23-amino acid peptide derived from human prothrombin that increases cartilage matrix production and reduces alkaline phosphatase activity without changing chondrocyte proliferation. This study tested the hypothesis that TP508 acts by blocking the onset of apoptosis associated with hypertrophy. Rat costochondral resting zone chondrocytes and human auricular chondrocytes were cultured in DMEM containing 50microM ascorbic acid and 10% FBS. Apoptosis was induced by treatment of confluent cultures with chelerythrine, tamoxifen, or inorganic phosphate (Pi) for 24h. One half of the cultures received TP508 (0, 0.7, or 7microg/ml). Apoptosis was assessed as a function of DNA fragmentation ([3H]-thymidine labeled DNA fragments), TUNEL staining, and cell viability using the MTT assay, as well as by assessing the Bcl-2/Bax mRNA and protein ratios and caspase-3 activity. The universal NO synthase inhibitor l-NMMA was used to assess the effect of NO production on chondrocyte apoptosis and specific NO synthase subspecies were identified using iNOS inhibitor 1400W and nNOS inhibitor vinyl-l-NIO, as well as l-NAME, which inhibits both iNOS and eNOS. Finally, we assessed if TP508 would block NO production induced by the apoptogens. Chelerythrine, tamoxifen and Pi-induced apoptosis and this was reversed by TP508. All apoptogens increased NO production and this was reduced by TP508. TP508 reduced NO levels to the same extent as 1400W but not to the same extent as l-NAME, suggesting that its effects are mediated primarily by iNOS. In addition, TP508 reduced the effect of chelerythrine to the same extent as 1400W and l-NAME, again indicating that it acts via inhibition of an iNOS pathway. TP508 also regulated Bcl-2/Bax mRNA in a time and dose-dependent manner. The Bcl-2/Bax mRNA ratio was 0.11 in the absence of TP508 at 1h and 4.95 at 7microg/ml TP508; by 3h the ratio was approximately 1 in both groups. The Bcl-2/Bax protein ratio also increased by 63% at 1h. TP508 did not affect caspase-3 activity. TP508 also caused a dose-dependent increase in protein kinase C (PKC) activity within 9min that was maximal at 270min. These results show that TP508 prevents apoptosis in growth plate chondrocytes via inhibition of iNOS-dependent NO and suggest a possible role for PKC in the mechanism.
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PMID:Thrombin peptide TP508 prevents nitric oxide mediated apoptosis in chondrocytes in the endochondral developmental pathway. 1802 91

Dexras1, a brain-enriched member of the Ras subfamily of GTPases, as a novel physiologic nitric oxide (NO) effector, anchor neuronal nitric oxide synthase (nNOS) that increased after spinal cord injury (SCI), to specific targets to enhance NO signaling, and is strongly and rapidly induced during treatment with dexamethasone. It is unknown how the central nervous system (CNS) trauma affects the expression of Dexras1. Here we used spinal cord transection (SCT) model to detect expression of Dexras1 at mRNA and protein level in spinal cord homogenates by real-time PCR and Western blot analysis. The results showed that Dexras1 mRNA upregulated at 3 day, 5 day, and 7 day significantly (P < 0.05) that was consistent with the protein level except at 7 day. Immunofluorescence revealed that both neurons and glial cells showed Dexras1 immunoreactivivty (IR) around SCT site, but the proportion is different. Importantly, injury-induced expression of Dexras1 was co-labeled by caspase-3 (apoptotic marker) and Tau-1 (marker for pathological oligodendrocyte). Furthermore, colocalization of Dexras1, carboxy-terminal PSD95/DLG/ZO-1 (PDZ) ligand of nNOS (CAPON) and nNOS was observed in neurons and glial cells, supporting the existence of ternary complexes in this model. Thus, the results that the transient high expression of Dexras1 which localized in apoptotic neurons and pathological oligodendrocytes might provide new insight into the secondary response after SCT.
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PMID:Spatiotemporal expression of Dexras1 after spinal cord transection in rats. 1821 71

In order to identify the apoptosis-induced factors and apoptosis pathway in hindlimb unloading muscle atrophy, the reciprocal relationships between caspase-3 activation and factors related to mitochondria, other organelle pathways, oxidative stress and nitric oxide were investigated. Male Wistar rats were divided into four groups, two groups of hindlimb-unloaded rats were maintained under normal (25 degrees C) and low-temperature (10 degrees C) environmental conditions for a 3-week experimental period, plus two corresponding control groups. Active caspase-3-containing myofibers were observed in the hindlimb-unloaded rats in normal and low-temperature environments, but not in the control rats. In these caspase-3-containing fibers, DNA fragmentation, dystrophin breakdown, increased immunolabeling of mu-calpain, decreased cytochrome c, cathepsin-D effusion from the lysosomes and increased lipid peroxidation were observed, while no changes in active caspase-12, eNOS or nNOS immunolabeling were seen. Furthermore, although caspase-3 activation was observed in type-I fibers, caspase-12 labeling was observed in fibers of the hybrid type. These results show that the apoptosis observed in hindlimb unloading-induced muscle atrophy is caused by activation of the caspase cascade via the lysosome pathway. Moreover, the results suggest that caspase-12 does not activate caspase-3 due to differences in the cell differentiation or the apoptosis-inducing stimulation.
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PMID:The activation of apoptosis factor in hindlimb unloading-induced muscle atrophy under normal and low-temperature environmental conditions. 1842 Feb 59

Pinocembrin is one of the flavonoids at the highest concentration in propolis. In this study, we investigated the neuroprotective effect of pinocembrin on ischemia/reperfusion and ischemia/reperfusion-like insults. Protection by pinocembrin was studied at the in vivo level using a model of middle cerebral artery occlusion and reperfusion in rats. Pinocembrin was administrated at the start of reperfusion. Pinocembrin markedly increased rat viability, reduced infarct volumes and neurological deficit scores in all treatment groups. Primary cortical neuronal cultures were subjected to oxygen-glucose deprivation/reoxygenation, a model of ischemia/reperfusion-like injury, and treated with pinocembrin at the start of reoxygenation. Neuronal survival rates were increased, LDH release was decreased and both neurite length and apoptosis were alleviated when pinocembrin was present during reoxygenation, and this protection was associated with the reduction of reactive oxygen species, nitric oxide and neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS), and an increase of glutathione. Moreover, DNA laddering was decreased in treatment groups of pinocembrin. Caspase-3 protein was down-regulated and PARP degradation was alleviated after pinocembrin treatments. Our results suggest that pinocembrin may be a novel therapeutic strategy to reduce cerebral ischemia/reperfusion injury, and may act by the anti-oxidative and anti-apoptotic effects.
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PMID:Pinocembrin protects rat brain against oxidation and apoptosis induced by ischemia-reperfusion both in vivo and in vitro. 1849 93


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