Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.30 (PARP)
13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Macro- and microvascular disease are the most common causes of morbidity and mortality in patients with diabetes mellitus. Diabetic cardiovascular dysfunction represents a problem of great clinical importance underlying the development of various severe complications including retinopathy, nephropathy, neuropathy and increase the risk of stroke, hypertension and myocardial infarction. Hyperglycemic episodes, which complicate even well-controlled cases of diabetes, are closely associated with increased oxidative and nitrosative stress, which can trigger the development of diabetic complications. Hyperglycemia stimulates the production of advanced glycosylated end products, activates protein kinase C, and enhances the polyol pathway leading to increased superoxide anion formation. Superoxide anion interacts with nitric oxide, forming the potent cytotoxin peroxynitrite, which attacks various biomolecules in the vascular endothelium, vascular smooth muscle and myocardium, leading to cardiovascular dysfunction. The pathogenetic role of nitrosative stress and peroxynitrite, and downstream mechanisms including poly(ADP-ribose) polymerase (PARP) activation, is not limited to the diabetes-induced cardiovascular dysfunction, but also contributes to the development and progression of diabetic nephropathy, retinopathy and neuropathy. Accordingly, neutralization of peroxynitrite or pharmacological inhibition of PARP is a promising new approach in the therapy and prevention of diabetic complications. This review focuses on the role of nitrosative stress and downstream mechanisms including activation of PARP in diabetic complications and on novel emerging therapeutical strategies offered by neutralization of peroxynitrite and inhibition of PARP.
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PMID:Role of nitrosative stress and peroxynitrite in the pathogenesis of diabetic complications. Emerging new therapeutical strategies. 1572 18

Nitric oxide (NO) derived from inducible NO synthase has been implicated in cardiac rejection. However, little is known about the role of the reactive nitrogen species peroxynitrite. We examined the protective actions of a peroxynitrite decomposition catalyst, WW85, in an experimental model of acute cardiac rejection. Heterotopic, abdominal transplantation of rat donor hearts was performed. Groups included isografts, allografts, or allografts treated with WW85, cyclosporine, or cyclosporine + WW85. We determined graft survival, histological rejection, and graft function (by in situ sonomicrometry). Intragraft biochemical analysis of cytokines and proapoptotic and antiapoptotic gene expression using reverse transcriptase-polymerase chain reaction were determined. Treatment with WW85 or cyclosporine alone prolonged graft survival, improved graft function, and decreased histological rejection. Graft survival was further significantly (P < 0.001) enhanced by combination treatment. A decrease was also shown in nitrotyrosine, poly(ADP-ribose) polymerase (PARP) activation, and lipid peroxide formation by WW85 that was potentiated when given in combination with cyclosporine. Benefits could not be ascribed to changes in intragraft myeloperoxidase activity. Only combination therapy produced significant decreases in inflammatory cytokine gene expression, suggesting that WW85 acted primarily downstream of these stimuli. In general, WW85 had no direct action on expression of the proapoptotic gene, Fas ligand; however, WW85 given alone or with cyclosporine enhanced expression of antiapoptotic genes Bcl-2 and Bcl-xL. Collectively, these findings suggest a protective action of the peroxynitrite decomposition catalyst WW85 on graft rejection that is independent of any action on leukocyte sequestration and cytokine gene expression. Rather, effects seem to be downstream on decreased protein nitration, decreased lipid peroxidation, and decreased PARP activation.
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PMID:Protective mechanisms of a metalloporphyrinic peroxynitrite decomposition catalyst, WW85, in rat cardiac transplants. 1578 53

Ulmus davidiana Nakai (UDN) has been used in folk medicine for its anti-inflammatory activity. In the present study, we investigated the antiapoptotic effect of UDN glycoprotein in glucose/glucose oxidase (G/GO)-induced BNL CL.2 cells. To evaluate the antiapoptotic effect of UDN glycoprotein, experiments were carried out using Western blot analysis for nuclear factor-kappa B (NF-kappaB), caspase-3, and poly(ADP-ribose) polymerase (PARP). We also examined nitric oxide (NO) production and nuclear staining. When BNL CL.2 cells were treated with G/GO (50 mU/ml), viability of the cells was 54.1%. However, the number of living cells after the addition of UDN glycoprotein in the presence of G/GO increased. UDN glycoprotein protected from cell damage caused by G/GO. Interestingly, UDN glycoprotein decreased NF-kappaB activation and stimulated NO production in G/GO-induced BNL CL.2 cells. In apoptotic parameters, UDN glycoprotein inhibited activations of caspase-3 and PARP cleavage in G/GO-induced BNL CL.2 cells. The results of nuclear staining indicated that UDN glycoprotein (50 microg/ml) has a protective ability from apoptotic cell death caused G/GO (50 mU/ml). In conclusion, UDN glycoprotein has a protective effect on apoptosis induced by G/GO through the inhibition of NF-kappaB, caspase-3, and PARP activity, and the stimulation of NO production in BNL CL.2 cells.
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PMID:116 kDa glycoprotein isolated from Ulmus davidiana Nakai (UDN) inhibits glucose/glucose oxidase (G/GO)-induced apoptosis in BNL CL.2 cells. 1591 75

Dysregulation of nitric oxide (NO) and increased oxidative and nitrosative stress are implicated in the pathogenesis of heart failure. Peroxynitrite is a reactive oxidant that is produced from the reaction of nitric oxide with superoxide anion and impairs cardiovascular function through multiple mechanisms, including activation of matrix metalloproteinases (MMPs) and nuclear enzyme poly(ADP-ribose) polymerase (PARP). Recent studies suggest that the neutralization of peroxynitrite or pharmacological inhibition of MMPs and PARP are promising new approaches in the experimental therapy of various forms of myocardial injury. In this article, the role of nitrosative stress and downstream mechanisms, including activation of MMPs and PARP, in various forms of heart failure are discussed and novel emerging therapeutic strategies offered by neutralization of peroxynitrite and inhibition of MMPs and PARP in these pathophysiological conditions are reviewed.
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PMID:Nitrosative stress and pharmacological modulation of heart failure. 1592 5

We examined, using young and old Brown-Norway rats, the involvement of the nitric oxide (NO)-mediated intrinsic pathway signaling in age-related activation of male germ-cell apoptosis. Increased apoptosis of germ cells was readily observed in the normal-looking testes of old rats. Testicular NO synthase (NOS) activity, assessed by measuring the synthesis of (3)H-L-citrulline from (3)H-L-arginine, and cytokine-inducible NO synthase (iNOS) levels, assessed by western blot assay, were increased significantly by 90% and 70%, respectively, in the old rats compared to that of young animals. Immunohistochemical analysis of age-related changes in the expression of iNOS in testes confirmed our findings based on western blot assay. Increased NO and germ-cell apoptosis during aging is further associated with cytosolic translocation of mitochondrial cytochrome c and poly (ADP) ribose polymerase (PARP) cleavage, thus, suggesting the involvement of NO-mediated intrinsic pathway signaling in age-related increase in germ-cell apoptosis in male Brown-Norway rats.
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PMID:Involvement of nitric oxide-mediated intrinsic pathway signaling in age-related increase in germ cell apoptosis in male Brown-Norway rats. 1598 71

Heart failure is the major cause of hospitalization, morbidity and mortality worldwide. Previous experimental and clinical studies have suggested that there is an increased production of reactive oxygen species (ROS: superoxide, hydrogen peroxide, hydroxyl radical) both in animals and in patients with acute and chronic heart failure. The possible source of increased ROS in the failing myocardium include xanthine and NAD(P)H oxidoreductases, cyclooxygenase, the mitochondrial electron transport chain and activated neutrophils among many others. The excessively produced nitric oxide (NO) derived from NO synthases (NOS) has also been implicated in the pathogenesis of chronic heart failure (CHF). The combination of NO and superoxide yields peroxynitrite, a reactive oxidant, which has been shown to impair cardiac function via multiple mechanisms. Increased oxidative and nitrosative stress also activates the nuclear enzyme poly(ADP-ribose) polymerase (PARP), which importantly contributes to the pathogenesis of cardiac and endothelial dysfunction associated with myocardial infarction, chronic heart failure, diabetes, atherosclerosis, hypertension, aging and various forms of shock. Recent studies have demonstrated that pharmacological inhibition of xanthine oxidase derived superoxide formation, neutralization of peroxynitrite or inhibition of PARP provide significant benefit in various forms of cardiovascular injury. This review discusses the role of oxidative/nitrosative stress and downstream pathways in various forms of cardiomyopathy and heart failure.
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PMID:Role of oxidative-nitrosative stress and downstream pathways in various forms of cardiomyopathy and heart failure. 1602 19

Complications of diabetes rather than the primary disease itself pose the most challenging aspects of diabetic patient management. Diabetic vascular dysfunction represents a problem of great clinical importance underlying the development of many of the complications including retinopathy, neuropathy and the increased risk of stroke, hypertension and myocardial infarction. Hyperglycaemia stimulates many cellular pathways, which result in oxidative stress, including increased production of advanced glycosylated end products, protein kinase C activation, and polyol pathway flux. Endothelial cells produce nitric oxide constitutively to regulate normal vascular tone; the combination of this nitric oxide with the hyperglycaemia-induced superoxide formation results in the production of reactive nitrogen species such as peroxynitrite. This nitrosative stress results in many damaging cellular effects, but it is these effects on DNA, which are the most damaging to the cell function; nitrosative stress induces DNA single stand breaks and leads to over-activation of the DNA repair enzyme poly (ADP-ribose) polymerase (PARP). PARP activation contributes to endothelial cell dysfunction and appears to be the central mediator in all the mechanisms by which hyperglycaemia-induces diabetic vascular dysfunction. This review focuses on the mechanism by which hyperglycaemia induces nitrosative stress and the role PARP activation plays in diabetic vascular dysfunction.
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PMID:Role of nitrosative stress and poly(ADP-ribose) polymerase activation in diabetic vascular dysfunction. 1602 21

Oxidative and nitrosative stress triggers DNA strand breakage, which then activates the nuclear enzyme poly(ADP-ribose) polymerase (PARP). Nitrogen-derived reactive oxidant species capable of involving DNA single strand breakage and PARP activation include peroxynitrite (the reaction product of nitric oxide and superoxide), but not nitric oxide per se. Activation of PARP may dramatically lower the intracellular concentration of its substrate, nicotinamide adenine dinucleotide, thus slowing the rate of glycolysis, electron transport, and subsequently ATP formation. This process can result in cell dysfunction and cell death. Here we review the role of reactive nitrogen species in the process of PARP activation, followed by the effect of pharmacological inhibition or genetic inactivation of PARP on the course of various forms of inflammation.
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PMID:Poly(ADP-ribose) polymerase activation by reactive nitrogen species--relevance for the pathogenesis of inflammation. 1611 3

Nitric oxide (NO) may block apoptosis by inhibiting caspases via S-nitrosylation of cysteines. Here, we investigated whether effector caspases might cleave and thereby inhibit endothelial nitric oxide synthase (eNOS). Exposure of eNOS-transfected COS-7 cells and bovine aortic endothelial cells to staurosporine resulted in significant loss of 135-kDa eNOS protein and activity, and appearance of a 60-kDa eNOS fragment; effects were inhibited by the general caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp[OMe]-fluoromethyl ketone (zVAD-fmk). In eNOS-transfected COS-7 cells, staurosporine-induced activation of caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage coincided with increased eNOS degradation and decreased activity. Loss of eNOS activity was greater than the degree of proteolysis. Incubation of immunoprecipitated eNOS with caspase-3, caspase-6 or caspase-7 resulted in eNOS cleavage. Staurosporine, a general protein kinase inhibitor, also reduced phosphorylation and decreased calmodulin binding, an effect that may explain the reduction in activity. eNOS, therefore, is both an inhibitor of apoptosis and a target of apoptosis-associated proteolysis.
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PMID:Effect of staurosporine-induced apoptosis on endothelial nitric oxide synthase in transfected COS-7 cells and primary endothelial cells. 1619 40

In this study, the effect of (Boc-Lys (Boc)-Arg-Asp-Ser (tBu)-OtBu), a tetrapeptide derivative (PEP1261) was examined for antiproliferative potency and apoptotic induction. Synovial fibroblasts were isolated from collagen-induced arthritic (CIA) rats and exposed to peptides viz., PEP1261, and parental peptides (KRDS and RGDS). Viability of the cells decreased in the presence of PEP1261 at a lower concentration (0.1 mM) when compared to RGDS and KRDS (1 mM). The treatment of cells with peptides showed induction of apoptosis, resulting in the cleavage of caspase-3 as well as its substrate poly-(ADP-ribose) polymerase (PARP). Pretreatment of cells with caspase-3 inhibitor prevented inhibition of [(3)H] thymidine incorporation, DNA fragmentation, and cleavage of caspase-3 and PARP as confirmed by western blotting as well as annexin-V/PI-staining using flow cytometry. However, caspase-1 and caspase-2 inhibitors did not prevent the peptides from inducing apoptosis indicating that caspase-3 might have a role in the process of apoptosis induced by peptides. Treatment of synovial fibroblasts with nitric oxide donor, S-nitroso-N-acetyl-DL: -penicillamine (SNAP) (500 microM) showed significant elevation of nitric oxide levels and resulted in absence of apoptosis by preventing the inhibition of [(3)H] thymidine incorporation. This was further evidenced by annexin V/propidium iodide (PI) staining and absence of DNA fragmentation, intra cellular caspase-3 activity and PARP cleavage. In contrast, SNAP followed by PEP1261 and parental peptides-induced apoptosis by lowering the levels of nitric oxide. These results suggested that PEP1261 suppressed the proliferation and induced apoptosis in cultured synovial fibroblasts from CIA rats. This study also confirmed that PEP1261 inhibited nitric oxide level in cultured synovial fibroblasts.
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PMID:Inhibition of nitric oxide and caspase-3 mediated apoptosis by a tetrapeptide derivative (PEP1261) in cultured synovial fibroblasts from collagen-induced arthritis. 1631 20


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