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)

Recently, we reported that a combination of indole-3-acetic acid (IAA) and horseradish peroxidase (HRP) induces apoptosis in G361 human melanoma cells. However, the apoptotic mechanism involved has been poorly studied. It is known that when IAA is oxidized by HRP, free radicals are produced, and since oxidative stress can induce apoptosis, we investigated whether reactive oxygen species (ROS) are involved in IAA/HRP-induced apoptosis. Our results show that IAA/HRP-induced free radical production is inhibited by catalase, but not by superoxide dismutase or sodium formate. Furthermore, catalase was found to prevent IAA/HRP-induced apoptotic cell death, indicating that IAA/HRP-produced hydrogen peroxide (H2O2) may be involved in the apoptotic process. Moreover, the antiapoptotic effect of catalase is potentiated by NADPH, which is known to protect catalase. On further investigating the IAA/HRP-mediated apoptotic pathway, we found that the IAA/HRP reaction leads to caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, which was also blocked by catalase. Additionally, we found that IAA/HRP produces H2O2 and induces peroxiredoxin (Prx) sulfonylation. Consequently, our results suggest that H2O2 plays a major role in IAA/HRP-induced apoptosis.
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PMID:Hydrogen peroxide is a mediator of indole-3-acetic acid/horseradish peroxidase-induced apoptosis. 1646 Jul 36

It has been shown that PARP inhibition is protective in several models of ischemia-reperfusion injury including cardiac, cerebral and renal ones. Due to their ability to reduce myocardial necrosis and to improve myocardial function PARP inhibitors emerged as candidates for treating various cardiovascular diseases including acute myocardial ischemia. Since the pathophysiology of acute ischemic cardiac diseases involves haemostatic impairment and the therapeutic regimen includes antithrombotic drugs, we investigated the effect of the potent poly(ADP-ribose) polymerase (PARP) inhibitor INO-1001 alone and in combination with platelet aggregation inhibitors (aspirin, eptifibatide and tirofiban), unfractionated heparin, low molecular weight heparin (enoxaparin) or the recombinant fibrinolytic drug (alteplase), on various haemostatic parameters in vitro. ADP- and epinephrine-induced platelet aggregation was evaluated by optical aggregometry in the presence or absence of different concentrations of INO-1001, in combination with aspirin, tirofiban, eptifibatide or saline on ten healthy volunteers' platelet rich plasma (PRP). Activated partial thromboplastin time, Anti-Xa activity and euglobulin lysis time were determined in the presence or absence of different concentrations of INO-1001, in combination with sodium heparin, enoxaparin or alteplase, respectively. INO-1001, on its own does not affect the measured platelet, and haemostatic functions, i.e. does not reduce the respective anti-platelet, anti-coagulant and thrombolytic activity of therapeutically relevant concentrations of aspirin, tirofiban, eptifibatide, enoxaparin and alteplase in vitro. INO-1001 enhanced the effects of heparins above therapeutic ranges; the magnitude of this effect was negligible. Consequently, the PARP inhibitor INO-1001 can be safely applied together with the drugs tested.
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PMID:In vitro effect of the potent poly(ADP-ribose) polymerase (PARP) inhibitor INO-1001 alone and in combination with aspirin, eptifibatide, tirofiban, enoxaparin or alteplase on haemostatic parameters. 1648 Jul 45

PCGEM1 is a prostate tissue-specific, and prostate cancer-associated noncoding RNA (ncRNA) gene. Previous results revealed a significant association of elevated PCGEM1 expression levels in prostate cancer cells of African-American patients, whose mortality rate is the highest among prostate cancer patients. Functional study of PCGEM1 demonstrated a marked increase in colony formation in LNCaP prostate cancer cells and NIH3T3 mouse fibroblast cells. This study demonstrates that PCGEM1 overexpression in LNCaP cell culture model results in the inhibition of apoptosis induced by doxorubicin (DOX). Induction of p53 and p21(Waf1/Cip1) by DOX were delayed in LNCaP cells stably overexpressing PCGEM1 (LNCaP-PCGEM1 cells) compared to control LNCaP cells. The protein levels of cleaved caspase 7, and cleaved PARP were attenuated in DOXtreated LNCaP-PCGEM1 cells compared to control LNCaP cells. Similar results were observed in LNCaP cells transiently overexpressing PCGEM1. The inhibition of PARP cleavage by PCGEM1 overexpression was also observed in LNCaP-PCGEM1 cells incubated with etoposide and sodium selenite. Fluorescence-Activated Cell Sorter Annexin-V analysis revealed significantly lower percentage of apoptotic cells in DOX-treated LNCaP-PCGEM1 cells compared to control LNCaP cells. The attenuation of apoptic response appears to be androgen dependent in this experimental model, as androgen-independent variants of LNCaP cells did not exhibit this response. In summary, this study provides new insights into cell biologic functions and novel features of an ncRNA. Further, these data unravel biological mechanisms of cell growth/cell survival-associated functions of this ncRNA in a widely used prostate cancer cell culture model.
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PMID:Regulation of apoptosis by a prostate-specific and prostate cancer-associated noncoding gene, PCGEM1. 1656 92

This study was aimed to examine the effects of homocysteine (Hcy) on vascular responsiveness of guinea-pig isolated pulmonary arteries and to investigate possible underlying mechanisms. In order to evaluate vascular reactivity, isometric tension studies were performed in response to potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP). Incubation of pulmonary artery rings with Hcy (10(-3)M, 180min) resulted in significant inhibition of response to ACh (an endothelium-dependent vasodilator)(E(max): 55.3+/-6.7 vs. 13.1+/-2.0(*), P<0.05) while SNP (an endothelium-independent vasodilator)-induced relaxation was not changed significantly. Furthermore, Hcy enhanced KCl- and Phe-induced contraction of pulmonary artery rings (E(max): 1568+/-81 vs. 2101+/-145(*)mg for KCl and 1081+/-101 vs. 1544+/-117(*)mg for Phe, P<0.05). Pulmonary artery ring contractions induced by stepwise addition to Ca(2+) to high KCl solution with no Ca(2+) were also significantly augmented by Hcy incubation (E(max): 1750+/-121 vs. 2295+/-134(*)mg, P<0.05). To investigate mechanisms of Hcy action, additional sets of experiments involving rings incubation with Hcy alone or with addition of Tiron (an intracellular superoxide anion scavenger, 10(-2)M), PJ34 (an inhibitor of polyADP-ribose polymerase, 3x10(-6)M), and combination of two antioxidant enzymes superoxide dismutase (SOD, 100U/ml) and catalase (CAT, 120U/ml) for 180min. The findings of our study clearly show that all these co-treatments significantly prevented the development of endothelial dysfunction induced by Hcy. Furthermore, the effect of Hcy on KCl- and Phe-induced contraction was significantly inhibited by the concomitant incubation with either SOD plus CAT, Tiron or PJ34. This study demonstrates that Hcy causes a significant alteration in vascular reactivity of pulmonary arteries, and this alteration seems to be via oxidative stress in pulmonary artery endothelium with subsequent DNA damage and activation of poly(ADP-ribose) polymerase (PARP) pathway.
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PMID:Homocysteine-induced changes in vascular reactivity of guinea-pig pulmonary arteries: role of the oxidative stress and poly (ADP-ribose) polymerase activation. 1662 37

Apoptosis of keratinocytes is a key mechanism required for epidermal homeostasis and the renewal of damaged cells. Its dysregulation has been implicated in many skin diseases including cancer and hyperproliferative disorders. In the present study, the effect of sodium butyrate, a histone deacetylase inhibitor, on keratinocyte apoptosis was investigated using the HaCaT human keratinocyte cell line. Sodium butyrate induced morphological changes associated with apoptosis and nuclear fragmentation of HaCaTs. Annexin V staining demonstrated that sodium butyrate induced apoptosis in a dose and time-dependent manner with 50% of HaCaTs apoptotic after exposure to 0.8 mg/ml sodium butyrate for 24 h. Apoptosis was associated with upregulation of cell surface expression of the death receptor Fas and activation of the extrinsic caspase pathway, with induction of caspase 8 activity peaking after 8 h. Caspase 3 activity peaked after 24 h and was associated with cleavage of the caspase 3 substrate, poly (ADP-ribose) polymerase (PARP). The intrinsic caspase pathway was not activated as caspase 9 activity was not detected, and there was no change in the expression of terminal differentiation markers keratin 10 and involucrin following sodium butyrate treatment. Together these results indicate that sodium butyrate is a potent inducer of Fas associated apoptosis via caspase activation in HaCaT keratinocytes, an effect that is independent of the induction of terminal differentiation.
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PMID:Sodium butyrate induced keratinocyte apoptosis. 1676 Nov 8

Overproduction of oxidants and free radicals in ageing tissues induces nitro-oxidative stress, which has recently been implicated in the pathogenesis of cardiovascular dysfunction associated with ageing. Peroxynitrite, a strong cytotoxic oxidant damages proteins and DNA and activates several pathways causing tissue injury, including the peroxynitrite-poly(ADP-ribose) polymerase (PARP) pathway. In this study, we investigated the effectiveness of the peroxynitrite decomposition catalyst FP15 on ageing-associated cardiac and vascular dysfunction. Young and ageing rats were treated with vehicle or FP15 intraperitoneally. Using a microtip Millar pressure catheter we performed left ventricular blood pressure analysis to assess systolic and diastolic function. Endothelium-dependent and -independent vasorelaxation of isolated aortic rings were investigated by using acetylcholine and sodium nitroprusside. Ageing animals showed a marked reduction of systolic and diastolic cardiac function and loss of endothelium-dependent relaxant responsiveness of aortic rings. FP15-treatment significantly improved cardiac performance and endothelial function. Immunohistochemical staining confirmed that FP15 effectively reduced nitrosative stress and prevented the activation of PARP in the aortic wall of ageing rats. Our results demonstrate the importance of endogenous peroxynitrite-overproduction in the pathogenesis of ageing-associated cardiovascular dysfunction. Pharmacological decomposition of peroxynitrite by FP15 may represent a novel therapeutic utility to improve cardiac and vascular dysfunction associated with ageing.
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PMID:The peroxynitrite decomposition catalyst FP15 improves ageing-associated cardiac and vascular dysfunction. 1711 20

Indole-3-acetic acid (IAA) activation by horseradish peroxidase (HRP) has been suggested as a new cancer therapy. Interestingly, we found that ultraviolet B UVB radiation also can activate IAA and produce free radicals in a dose-dependent manner. In this study, we attempted to identify the free radicals generated by UVB-irradiated IAA (IAAUVB), and to determine whether IAAUVB can induce the apoptosis of G361 human melanoma cells. Since IAA/HRP produces reactive oxygen species (ROS), we examined whether IAAUVB-generated radicals include ROS. Our results show that IAAUVB-induced free radical production is not inhibited by catalase, superoxide dismutase, or sodium formate, indicating that ROS are not generated by IAAUVB. On the other hand, IAAUVB caused lipid peroxidation, and this was blocked by Trolox, a water-soluble vitamin E derivative. Moreover, we found that IAAUVB caused apoptotic cell death and that this was inhibited by a low temperature. We further investigated IAAUVB-mediated apoptotic pathways, and found that IAAUVB causes caspase-8, Bid, caspase-3 activation, and poly (ADP-ribose) polymerase (PARP) cleavage. In addition, these apoptotic pathways were also blocked by low temperature. From these results, we propose that IAAUVB-induced free radicals cause human melanoma cell apoptosis via a death receptor-mediated apoptotic pathway.
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PMID:Light-activated indole-3-acetic acid induces apoptosis in g361 human melanoma cells. 1714 72

We report that the effect of Tau-Cl on the cell fate strongly depends on the cellular context. In leukemic Jurkat cells Tau-Cl (> 200 microM) triggers mitochondrial, p53-independent apoptosis and amplifies PCD induced by anti-Fas treatment. In contrast, Tau-Cl affects RA FLS in a dose-dependent manner. At the noncytotoxic (200-400 microM) concentrations it induces: (i) p53-dependent growth arrest (Kontny et al., 2005), and (ii) Bax translocation and caspase 9 activity. Although the last events are characteristic for apoptotic state, there is not execution of RA FLS apoptosis, probably due to simultaneous inhibition of caspase 3 activity and prevention of PARP degradation. The last two events suggest an excessive ATP deprivation in Tau-Cl-treated RA FLS. At sufficiently high concentrations (> or = 500 microM) Tau-Cl causes therefore necrosis of these cells. Altogether our results suggest that Tau-Cl is able to eliminate the cells with both functional (RA FLS) and mutated (Jurkat) p53 tumor suppressor. This observation is clinically relevant because Tau-Cl is used in many animal inflammatory models and its sodium salt (used in this study) has been introduced to human therapy (Gottardi and Nagl, 2002; Teuchner et al., 2005).
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PMID:Cytotoxicity of taurine metabolites depends on the cell type. 1715 99

Common practice to evaluate the efficacy of any compound as drug is done in cell-based in vitro system followed by in vivo murine model prior to clinical trial in human. Cardiac glycosides are very effective to kill human cells, but not murine cells. In this report, we describe the comparative molecular mechanism of oleandrin, a cardiac glycoside action in human and murine cells. Treatment with oleandrin facilitated nuclear translocation of FKHR in human, but not murine cells by dephosphorylating Akt. It activated MAPK and JNK in human, but not in murine cells and also induced expression of FasL leads to apoptosis in human cells as detected by assaying caspases activation, PARP cleavage, nuclear fragmentation, and annexin staining. Oleandrin interacted with human plasma membrane as evaluated by HPLC, altered its fluidity as detected by DPH binding, inhibited Na+/K+-ATPase activity, and increased intracellular free Ca2+ level followed by calcineurin activity only in human, but not in murine cells. Results suggest that human plasma membrane might be different than murine, which interact with oleandrin that disturb Na+/K+-ATPase pump resulting in the calcification followed by induction of Ca2+-dependent cellular responses such as apoptosis.
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PMID:Oleandrin induces apoptosis in human, but not in murine cells: dephosphorylation of Akt, expression of FasL, and alteration of membrane fluidity. 1717 71

TRPM2 is a cation channel enabling influx of Na+ and Ca2+, leading to depolarization and increases in the cytosolic Ca2+ concentration ([Ca2+]i). It is widely expressed, e.g. in many neurons, blood cells and the endocrine pancreas. Channel gating is induced by ADP-ribose (ADPR) that binds to a Nudix box motif in the cytosolic C-terminus of the channel. Endogenous ADPR concentrations in leucocytes are sufficiently high to activate TRPM2 in the presence of an increased [Ca2+]i but probably not at resting [Ca2+]i. Another channel activator is oxidative stress, especially hydrogen peroxide (H2O2) that may act through ADPR after ADPR polymers have been formed by poly(ADP-ribose) polymerases (PARPs) and hydolysed by glycohydrolases. H2O2-stimulated TRPM2 channels essentially contribute to insulin secretion in pancreatic beta-cells and alloxan-induced diabetes mellitus. Inhibition of TRPM2 channels may be achieved by channel blockers such as flufenamic acid or the anti-fungal agents clotrimazole or econazole. Selective blockers of TRPM2 are not yet available; those would be valuable for a characterization of biological roles of TRPM2 in various tissues and as potential drugs directed against oxidative cell damage, reperfusion injury or leucocyte activation. Activation of TRPM2 may be prevented by anti-oxidants, PARP inhibitors and glycohydrolase inhibitors. In future, binding of ADPR to the Nudix box may be targeted. In light of the wide-spread expression and growing list of cellular functions of TRPM2, useful therapeutic applications are expected for future drugs that block TRPM2 channels or inhibit their activation.
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PMID:TRPM2. 1721 61


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