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)

Cigarette smoking is the major cause of preventable morbidity and mortality in the United States and constitutes a major risk factor for atherosclerotic vascular disease, including coronary artery disease and stroke. Increasing evidence supports the hypothesis that oxidative stress and inflammation provide the pathophysiological link between cigarette smoking and CAD. Previous studies have shown that cigarette smoke activates leukocytes to release reactive oxygen and nitrogen species (ROS/RNS) and secrete pro-inflammatory cytokines, increases the adherence of monocytes to the endothelium and elicits airway inflammation. Here we present an overview of the direct effects of water-soluble cigarette smoke constituents on endothelial function, vascular ROS production and inflammatory gene expression. The potential pathogenetic role of peroxynitrite formation, and downstream mechanisms including poly(ADP-ribose) polymerase (PARP) activation in cardiovascular complications in smokers are also discussed.
 ...
PMID:Oxidative stress and accelerated vascular aging: implications for cigarette smoking. 1927 62

UV solar radiation is the major environmental risk factor for malignant melanoma. A great effort is currently posed on the search of new compounds able to prevent or reduce UV-mediated cell damage. Ferulic acid is a natural compound recently included in the formulation of solar protecting dermatological products. The purpose of the present work was to assess whether its ethyl ester derivative, FAEE, could protect skin melanocytes from UV-induced oxidative stress and cell damage. Experiments on human melanocytes irradiated with UVB showed that FAEE treatment reduced the generation of ROS, with a net decrease of protein oxidation. FAEE treatment was accompanied by an induction of HSP70 and heme oxygenase, by a marked suppression of PARP activation and a significant suppression of apoptosis. Moreover FAEE prevented iNOS induction, thus suppressing the secondary generation of NO-derived oxidizing agents. FAEE may represent a potentially effective pharmacological approach to reduce UV radiation-induced skin damage.
 ...
PMID:Protective effect of ferulic acid ethyl ester against oxidative stress mediated by UVB irradiation in human epidermal melanocytes. 1927 91

Vascular dysfunction occurs with aging. We hypothesized that oxidative stress and ANG II [acting via ANG II type 1 (AT(1)) receptors] promotes cerebral vascular dysfunction with aging. We studied young (5-6 mo), old (17-19 mo), and very old (23 +/- 1 mo) mice. In basilar arteries in vitro, acetylcholine (an endothelium-dependent agonist) produced dilation in young wild-type mice that was reduced by approximately 60 and 90% (P < 0.05) in old and very old mice, respectively. Similar effects were seen using A23187, a second endothelium-dependent agonist. The vascular response to acetylcholine in very old mice was almost completely restored with tempol (a scavenger of superoxide) and partly restored by PJ34, an inhibitor of poly(ADP-ribose) polymerase (PARP). We used mice deficient in Mn-SOD (Mn-SOD(+/-)) to test whether this form of SOD protected during aging but found that age-induced endothelial dysfunction was not altered by Mn-SOD deficiency. Cerebral vascular responses were similar in young mice lacking AT(1) receptors (AT(1)(-/-)) and wild-type mice. Vascular responses to acetylcholine and A23187 were reduced by approximately 50% in old wild-type mice (P < 0.05) but were normal in old AT(1)-deficient mice. Thus, aging produces marked endothelial dysfunction in the cerebral artery that is mediated by ROS, may involve the activation of PARP, but was not enhanced by Mn-SOD deficiency. Our findings suggest a novel and fundamental role for ANG II and AT(1) receptors in age-induced vascular dysfunction.
 ...
PMID:Role of oxidative stress and AT1 receptors in cerebral vascular dysfunction with aging. 1939 52

PARP inhibitors combined with DNA-damage inducing cytostatic agents can lead to effective tumor therapy. However, inhibition of poly(ADP-ribose) polymerase (PARP-1; EC 2.4.2.30) induces the activation of PI-3-kinase-Akt pathway, which can counteract the effectiveness of this therapy. To understand the role of Akt activation in the combined use of cytostatic agent and PARP inhibition, we used taxol (paclitaxel) as an antineoplastic agent, which targets microtubules and up-regulates mitochondrial ROS production, together with (i) pharmacological inhibition (PJ-34), (ii) siRNA knock-down and (iii) transdominant expression of the DNA binding domain of PARP-1. In all cases, PARP-1 inhibition leads to suppressed poly-ADP-ribosylation of nuclear proteins, prevention of NAD(+) depletion and significant resistance against taxol induced caspase-3 activation and apoptotic cell death. Paclitaxel induced a moderate increase in Akt activation, which was significantly augmented by PARP inhibition, suggesting that PARP inhibition-induced Akt activation could be responsible for the cytostatic resistance. When activation of the PI-3-kinase-Akt pathway was prevented by LY-294002 or Akt Inhibitor IV, the cytoprotective effect of PARP inhibition was significantly diminished showing that the activation of PI-3-kinase-Akt cascade had significantly contributed to the cytostatic resistance. Our study demonstrates that drug-induced drug resistance can be responsible for the reduced efficacy of antitumor treatment. Although inhibition of PARP-1 can promote cell death in tumor cells by the inhibition of DNA repair, PARP-inhibition promoted activation of the PI-3-kinase-Akt pathway can counteract this facilitating effect, and can cause cytostatic resistance. We suggest augmenting PARP inhibition by the inhibition of the PI-3-kinase-Akt pathway for antitumor therapy.
 ...
PMID:PARP-1 inhibition-induced activation of PI-3-kinase-Akt pathway promotes resistance to taxol. 1942 73

Combined effects of alprazolam (Alp), a member of benzodiazepine group of drugs and caffeine on human cell lines, HeLa and THP1 were investigated in this study. Alp mediated cytotoxicity was enhanced while caffeine was present. The cell death was confirmed by observing morphological changes, LDH assay and membrane anisotropic study. Also such combined effects induced elevated level of ROS and depletion of GSH. The mechanism of cell death induced by simultaneous treatment of Alp and caffeine was associated with the calcium-mediated activation of mu-calpain, release of lysosomal protease cathepsin B, activation of PARP and cleavage of caspase 3. Our results indicate that, Alp alone induces apoptosis in human cells but in the presence of caffeine it augments necrosis in a well-regulated pathway. Thus our observations strongly suggest that, alprazolam and caffeine together produce severe cytotoxicity in human cell lines.
 ...
PMID:Caffeine augments Alprazolam induced cytotoxicity in human cell lines. 1949 Sep 37

In this study, the protective effects of water extracts from pine needle (WEPN) against DNA damage and apoptosis induced by hydroxyl radical were investigated in non-cellular and cellular system. WEPN exhibited strong scavenging action on hydroxyl radical and intracellular ROS, and chelating action of Fe(2+) ion. WEPN inhibited oxidative DNA damage by hydroxyl radical. Also, WEPN prevented the cells from oxidative damage through lowering p21 and BAX protein expression, blocking the cleavage of PARP and increasing Bcl-2 protein, which was confirmed by Hoechst 33342 staining. These data indicate that WEPN possesses a spectrum of antioxidant and DNA-protective properties common to cancer chemopreventive agents.
 ...
PMID:Effect of extracts from pine needle against oxidative DNA damage and apoptosis induced by hydroxyl radical via antioxidant activity. 1950 Jun 37

The energy reduction-induced death of retinal ganglion cells is associated with many ophthalmic diseases. The present study was designed to investigate the apoptosis pathway of retinal ganglion cells (RGC-5) following acute ATP reduction by using glucose deprivation (GD). RGC-5 cells were cultured in glucose-free or normal DMEM for 3 days. The changes in intracellular ATP and cell viability were monitored by ATP assay and MTT assay. APOPercentage and in situ TUNEL assays were used to determine the cell death pattern. The involvement of oxidative stress was assessed by measuring intracellular ROS generation, the HO-1 expression, the effect of antioxidants, and the ratio of GSSG to total GSH. The activation of p53 and apoptosis markers was evaluated by Western blotting. We found that glucose deprivation caused an acute decline of intracellular ATP level, concomitantly decreasing cell viability. The cell death exhibited typical features indicative of apoptosis, including cell shrinkage, phosphatidylserine externalization and DNA fragmentation. Oxidative stress was involved in the cell death process; an antioxidant significantly protected the cells against glucose deprivation. p53 and apoptosis markers, caspase-3 and PARP-1 were activated after RGC-5 cells were cultured in glucose-free media for 32 h. Z-VAD-fmk, a pan-caspase inhibitor, was sufficient to prevent apoptosis. These results suggest that acute energy reduction induced by glucose deprivation triggers caspase-dependent apoptosis and activates p53. Blocking the critical steps in this cell death pathway may have therapeutic effects, rescuing the retinal ganglion cells from damages associated with acute energy reduction.
 ...
PMID:Acute energy reduction induces caspase-dependent apoptosis and activates p53 in retinal ganglion cells (RGC-5). 1952 68

The hydroxyl groups of flavonoids are important for their bioactive functions and also prone to oxidation to quinones. To block the potential oxidation of quercetin, and generate a stronger bioactive compound, we synthesized acetyl and methyl derivatives of quercetin, 3,7,3',4'-O-tetraacetylquercetin (4Ac-Q) and 3,7,3',4'-O-tetramethylquercetin (4Me-Q), which substituted the hydroxyl groups of quercetin with acetyl or methyl groups at the 3,7,3',4' positions of quercetin, and then evaluated the ability to cause cell proliferation inhibition and apoptosis in HL-60 cells. The results revealed that 4Ac-Q and quercetin, but not 4Me-Q, significantly inhibit cell proliferation by caspase-mediated apoptosis when characterized by DNA fragmentation, activation of caspase-3 and PARP cleavage while 4Me-Q lost this ability. Interestingly, 4Ac-Q revealed stronger apoptotic activity than parent quercetin via a ROS-independent pathway. These findings provide a valuable strategy to increase the sensitivity of human leukemia HL-60 cells toward apoptosis by modifying quercetin structure.
 ...
PMID:Acetyl derivate of quercetin increases the sensitivity of human leukemia cells toward apoptosis. 1956 72

This paper was to explore bullatacin-mediated multidrug-resistant cell apoptosis at extremely low concentration. To investigate its precise mechanisms, the pathway of cell apoptosis induced by bullatacin was examined. Bullatacin causes an upregulation of ROS and a downregulation of DeltaPsi(m) in a concentration-dependent manner in ABCB1-overexpressing KBv200 cells. In addition, cleavers of caspase-9, caspase-3, and PARP were observed following the release of cytochrome c from mitochondria after bullatacin treatment. However, neither cleavage of caspase-8 nor change of expression level of bcl-2, bax and Fas was observed by the same treatment. Pretreating KBv200 cells with N-acetylcysteine, an antioxidant modulator, resulted in a significant reduction of ROS generation and cell apoptosis induced by bullatacin. Bullatacin-induced apoptosis was antagonized by z-LEHD-fmk, a caspase-9 inhibitor, but not by z-IETD-fmk, a caspase-8 inhibitor. These implied that apoptosis of KBv200 cells induced by bullatacin was associated with the mitochondria-dependent pathway that was limited to activation of apical caspase-9.
 ...
PMID:Bullatacin triggered ABCB1-overexpressing cell apoptosis via the mitochondrial-dependent pathway. 1963 48

Oxidative stress resulting in excessive generation of ROS is a compelling initiator of DNA damage along with damage to various cellular proteins and other macromolecules. Poly(ADP-ribose) polymerase (PARP) activation in response to DNA damage, stirs an energy-consuming cellular metabolic cycle; culminating into cell death. The present study was designed to determine the effect of combining an antioxidant, Melatonin and a PARP inhibitor, Nicotinamide on the hallmark deficits developing in diabetic neuropathy (DN). Streptozotocin (STZ, 55 mg/kg, i.p.) was administered to induce diabetes. Six weeks post diabetes induction, two week treatment with Melatonin (3 and 10 mg/kg) and Nicotinamide (100 and 300 mg/kg) either alone or in combination was given. Effect of these interventions on the functional, behavioral and biochemical changes caused by hyperglycemia were studied in treated animals. Melatonin and Nicotinamide alone as well as in combination ameliorated the functional deficits along with improvement in pain parameters. The combination also demonstrated an essential reversal of biochemical alterations. Nitrotyrosine and Poly ADP Ribose (PAR) immunopositivity was significantly decreased in sciatic nerve micro-sections of treatment group. The results of this study advocate that simultaneous inhibition of oxidative stress-PARP activation cascade may prove useful for the pharmacotherapy of DN.
 ...
PMID:Functional and biochemical evidence indicating beneficial effect of Melatonin and Nicotinamide alone and in combination in experimental diabetic neuropathy. 2000 37


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