Cyclic ADP-ribose (cADPR) releases Ca²⁺ from ryanodine receptor (RyR)-sensitive calcium pools in various cell types. In cardiac myocytes, the physiological levels of cADPR transiently increase the amplitude and frequency of Ca²⁺ (that is, a rapid increase and decrease of calcium within one second) during the cardiac action potential. In this study, we demonstrated that cADPR levels higher than physiological levels induce a slow and gradual increase in the resting intracellular Ca²⁺ ([Ca²⁺](i)) level over 10 min by inhibiting the sarcoendoplasmic reticulum Ca²⁺ ATPase (SERCA). Higher cADPR levels mediate the tyrosine-dephosphorylation of α-actin by protein tyrosine phosphatase 1B (PTP1B) present in the endoplasmic reticulum. The tyrosine dephosphorylation of α-actin dissociates phospholamban, the key regulator of SERCA, from α-actin and results in SERCA inhibition. The disruption of the integrity of α-actin by cytochalasin B and the inhibition of α-actin tyrosine dephosphorylation by a PTP1B inhibitor block cADPR-mediated Ca²⁺ increase. Our results suggest that levels of cADPR that are relatively higher than normal physiological levels modify calcium homeostasis through the dephosphorylation of α-actin by PTB1B and the subsequent inhibition of SERCA in cardiac myocytes.
Action Potentials ; Adenosine Diphosphate* ; Adenosine Triphosphatases ; Calcium ; Cyclic ADP-Ribose ; Cytochalasin B ; Endoplasmic Reticulum ; Homeostasis ; Muscle Cells* ; Myocytes, Cardiac ; Protein Tyrosine Phosphatase, Non-Receptor Type 1* ; Protein Tyrosine Phosphatases* ; Reticulum ; Ryanodine Receptor Calcium Release Channel ; Tyrosine

After renal injury, selective damage occurs in the proximal tubules as a result of inhibition of glycolysis. The molecular mechanism of damage is not known. Poly(ADP-ribose) polymerase (PARP) activation plays a critical role of proximal tubular cell death in several renal disorders. Here, we studied the role of PARP on glycolytic flux in pig kidney proximal tubule epithelial LLC-PK1 cells using XFp extracellular flux analysis. Poly(ADP-ribosyl)ation by PARP activation was increased approximately 2-fold by incubation of the cells in 10 mM glucose for 30 minutes, but treatment with the PARP inhibitor 3-aminobenzamide (3-AB) does-dependently prevented the glucose-induced PARP activation (approximately 14.4% decrease in 0.1 mM 3-AB-treated group and 36.7% decrease in 1 mM 3-AB-treated group). Treatment with 1 mM 3-AB significantly enhanced the glucose-mediated increase in the extracellular acidification rate (61.1±4.3 mpH/min vs. 126.8±6.2 mpH/min or approximately 2-fold) compared with treatment with vehicle, indicating that PARP inhibition increases only glycolytic activity during glycolytic flux including basal glycolysis, glycolytic activity, and glycolytic capacity in kidney proximal tubule epithelial cells. Glucose increased the activities of glycolytic enzymes including hexokinase, phosphoglucose isomerase, phosphofructokinase-1, glyceraldehyde-3-phosphate dehydrogenase, enolase, and pyruvate kinase in LLC-PK1 cells. Furthermore, PARP inhibition selectively augmented the activities of hexokinase (approximately 1.4-fold over vehicle group), phosphofructokinase-1 (approximately 1.6-fold over vehicle group), and glyceraldehyde-3-phosphate dehydrogenase (approximately 2.2-fold over vehicle group). In conclusion, these data suggest that PARP activation may regulate glycolytic activity via poly(ADP-ribosyl)ation of hexokinase, phosphofructokinase-1, and glyceraldehyde-3-phosphate dehydrogenase in kidney proximal tubule epithelial cells.
Animals ; Cell Death ; Epithelial Cells* ; Glucose ; Glucose-6-Phosphate Isomerase ; Glycolysis ; Hexokinase ; Kidney* ; LLC-PK1 Cells ; Oxidoreductases ; Phosphofructokinase-1 ; Phosphopyruvate Hydratase ; Poly Adenosine Diphosphate Ribose* ; Poly(ADP-ribose) Polymerases* ; Pyruvate Kinase ; Swine

A nucleoside diphosphate-linked moiety X (Nudix) hydrolase-like gene, YSA1, has been identified as one of the gromwell plant extract-responsive genes in Cryptococcus neoformans. Ysa1 is known to control intracellular concentrations of ADP-ribose or O-acetyl-ADP-ribose, and has diverse biological functions, including the response to oxidative stress in the ascomycete yeast, Saccharomyces cerevisiae. In this study, we characterized the role of YSA1 in the stress response and adaptation of the basidiomycete yeast, C. neoformans. We constructed three independent deletion mutants for YSA1, and analyzed their mutant phenotypes. We found that ysa1 mutants did not show increased sensitivity to reactive oxygen species-producing oxidative damage agents, such as hydrogen peroxide and menadione, but exhibited increased sensitivity to diamide, which is a thiol-specific oxidant. Ysa1 was dispensable for the response to most environmental stresses, such as genotoxic, osmotic, and endoplasmic reticulum stress. In conclusion, modulation of YSA1 may regulate the cellular response and adaptation of C. neoformans to certain oxidative stresses and contribute to the evolution of antifungal drug resistance.
Adenosine Diphosphate Ribose ; Ascomycota ; Basidiomycota ; Cryptococcus neoformans* ; Cryptococcus* ; Diamide ; Drug Resistance, Fungal ; Endoplasmic Reticulum Stress ; Hydrogen Peroxide ; Lithospermum ; O-Acetyl-ADP-Ribose ; Oxidative Stress* ; Oxygen ; Phenotype ; Plants ; Saccharomyces cerevisiae ; Vitamin K 3 ; Yeasts

The morbidity of neurodegenerative diseases are increased in recent years, however, the treatment is limited. Poly ADP-ribosylation (PARylation) is a post-translational modification of protein that catalyzed by poly(ADP-ribose) polymerase (PARP). Studies have shown that PARylation is involved in many neurodegenerative diseases such as stroke, Parkinson's diseases, Alzheimer's disease, amyotrophic lateral sclerosis and so on, by affecting intracellular translocation of protein molecules, protein aggregation, protein activity, and cell death. PARP inhibitors have showed neuroprotective efficacy for neurodegenerative diseases in pre-clinical studies and phase Ⅰ clinical trials. To find new PARP inhibitors with more specific effects and specific pharmacokinetic characteristics will be the new direction for the treatment of neurodegenerative diseases. This paper reviews the recent progress on PARylation in neurodegenerative diseases.
ADP-Ribosylation ; Humans ; Neurodegenerative Diseases ; physiopathology ; Poly Adenosine Diphosphate Ribose ; Poly(ADP-ribose) Polymerases ; metabolism

BACKGROUND: ADP-ribosyl pyrophosphatases (ADPRase) has been known to catalyze the hydrolysis of ADP-ribose to ribose-5-phosphate and AMP. The role of ADPRase has been suggested to sanitize the cell by removing potentially toxic ADP-ribose. In this study, we examined the effect of nitric oxide on ADPRase activity in macrophages. METHODS: ADPRase activity was measured in NO-inducing J774 cells. For in vitro experiments, recombinant human ADPRase was prepared in bacteria. RESULTS: ADPRase activity was increased by the treatment of exogenous NO generating reagent, sodium nitroprusside (SNP), in J774 cells. The increased ADPRase activity was mediated by the post-translational modification, likely to cause cADP-ribosylation via nitrosylation of cysteine residue on the enzyme. The stimulation with endogeneous NO inducers, TNF-alpha/IFN-gamma, also increased ADPRase activity through NO synthesis. Futhermore, ADPRase activity may be mediated by the post-translational modification of ADPRase, ADP-ribosylation. CONCLUSION: These results indicate that NO synthesized by macrophage activation plays a critical role in the increase in ADPRase activity following ADP-ribose metabolism.
Adenosine Diphosphate Ribose* ; Bacteria ; Cysteine ; Humans ; Hydrolysis ; Macrophage Activation ; Macrophages ; Metabolism ; Nitric Oxide* ; Nitroprusside ; Protein Processing, Post-Translational ; Pyrophosphatases

OBJECTIVE: There are some evidences that some epithelial ovarian cancer cells respond to hormonal therapy. And in vitro studies have revealed that treatment of various human cancer cell lines with selective cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to evaluate the effects of tamoxifen and celecoxib, a selective COX-2 inhibitor, on the ovarian cancer cells and the benefits of combining these agents in the management of ovarian cancer. METHODS: SK-OV-3 epithelial ovarian cancer cells were exposed to increasing concentration of tamoxifen (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 h of continuous exposure. Concomitant treatment of SK-OV-3 cells with tamoxifen and celecoxib induced significant increase in apoptosis, comparing with single drug exposure. The pattern of apoptosis induced by these agents on SK-OV-3 cells seemed to be caspase-3 dependent. CONCLUSION: Our data suggest that combining tamoxifen with selective COX-2 inhibitor seems to have at least an additive tumoricidal effect. A more definitive role for this combination therapy in clinical settings in ovarian cancer will need to be defined through the conduct of clinical trials.
Adenosine Diphosphate Ribose ; Apoptosis ; Caspase 3 ; Cell Death ; Cell Line* ; Cyclooxygenase 2 ; Humans ; Ovarian Neoplasms* ; Tamoxifen* ; Celecoxib

OBJECTIVE: In vitro studies have revealed that treatment of various human cancer cell lines with specific cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to investigate the benefits of combining COX-2 inhibitors with existing treatment modalities in the management of ovarian cancer. METHODS: In this study we sought to determine the effects of combining paclitaxel and the COX-2 inhibitor celecoxib on apoptosis of epithelial ovarian cancer (EOC) cells. SK-OV-3 cells were exposed to increasing concentrations of paclitaxel (10(-7) M, 10(-6) M and 10(-5) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 hours of continuous exposure. But concomitant treatment of SK-OV-3 EOC cell line with paclitaxel and celecoxib resulted in marked impairment of paclitaxel-induced apoptosis. The pattern of apoptosis induced by paclitaxel on SK-OV-3 EOC cell line was caspase-3 independent. CONCLUSION: Combining COX-2 inhibitors and paclitaxel does not have an additive or synergistic tumoricidal effect. On the contrary, celecoxib treatment markedly inhibited the apoptotic effects of paclitaxel in SK-OV-3 EOC cell line.
Adenosine Diphosphate Ribose ; Apoptosis* ; Caspase 3 ; Cell Death ; Cell Line* ; Cyclooxygenase 2 ; Cyclooxygenase 2 Inhibitors ; Humans ; Ovarian Neoplasms* ; Paclitaxel ; Celecoxib

Extracellular nicotinamide adenine dinucleotide (NAD) cleaving activity of a particular cell type determines the rate of the degradation of extracellular NAD with formation of metabolites in the vicinity of the plasma membrane, which has important physiological consequences. It is yet to be elucidated whether intact human neutrophils have any extracellular NAD cleaving activity. In this study, with a simple fluorometric assay utilizing 1,N6-ethenoadenine dinucleotide (etheno-NAD) as the substrate, we have shown that intact peripheral human neutrophils have scant extracellular etheno-NAD cleaving activity, which is much less than that of mouse bone marrow neutrophils, mouse peripheral neutrophils, human monocytes and lymphocytes. With high performance liquid chromatography (HPLC), we have identified that ADP-ribose (ADPR) is the major extracellular metabolite of NAD degradation by intact human neutrophils. The scant extracellular etheno-NAD cleaving activity is decreased further by N-formyl-methionine-leucine-phenylalanine (fMLP), a chemoattractant for neutrophils. The fMLP-mediated decrease in the extracellular etheno-NAD cleaving activity is reversed by WRW4, a potent FPRL1 antagonist. These findings show that a much less extracellular etheno-NAD cleaving activity of intact human neutrophils compared to other immune cell types is down-regulated by fMLP via a low affinity fMLP receptor FPRL1.
Adenosine Diphosphate Ribose ; Animals ; Bone Marrow ; Cell Membrane ; Chromatography, Liquid ; Humans ; Lymphocytes ; Mice ; Monocytes ; NAD* ; Neutrophils* ; Receptors, Formyl Peptide

ADP-ribosyltransferase (ADPRT) catalyzes the reaction in which the ADP-ribose moiety of beta-NAD+ is transferred to specific amino acid residues in target proteins. The ADPRT of Mycobacterium smegmatis has been known to inactivate rifampin through ADP-ribosylation. However, the enzymatic characteristics and functions of the enzyme have not been elucidated yet. In this study, the ADPRT-glutathione S-transferase (GST) fusion protein was expressed in Escherichia coli and enzymatic characteristics of the fusion protein were investigated. ADPRT-GST fusion protein was an ADPribosyltransferase that had no NAD glycohydrolase activity. ADPRT-GST fusion protein showed no self-inactivation phenomenon that is a universal nature for all NAD glycohydrolases and is important in regulating its activity. ADPRT activity of the enzyme was decreased by novobiocin and isonicotinic acid hydrazide. These results suggest that Mycobacterium smegmatis ADPRT could be regulated by a different way from other NADases and involved in bacterial physiological process through a post-translational modification of cytosolic proteins.
Adenosine Diphosphate Ribose ; ADP Ribose Transferases* ; Cytosol ; Escherichia coli ; Isoniazid ; Mycobacterium smegmatis* ; Mycobacterium* ; NAD+ Nucleosidase ; Novobiocin ; Physiological Processes ; Protein Processing, Post-Translational ; Rifampin

Poly ADP-ribose polymerase inhibitors (PARPi), which approved in recent years, are recommended for ovarian cancer, breast cancer, pancreatic cancer, prostate cancer and other cancers by The National Comprehensive Cancer Network (NCCN) and Chinese Society of Clinical Oncology (CSCO) guidelines. Because most of PARPi are metabolized by cytochrome P450 enzyme system, there are extensive interactions with other drugs commonly used in cancer patients. By setting up a consensus working group including pharmaceutical experts, clinical experts and methodology experts, this paper forms a consensus according to the following steps: determine clinical problems, data retrieval and evaluation, Delphi method to form recommendations, finally formation expert opinion on PARPi interaction management. This paper will provide practical reference for clinical medical staff.
Male ; Female ; Humans ; Poly(ADP-ribose) Polymerase Inhibitors/pharmacology* ; Consensus ; Ovarian Neoplasms/drug therapy* ; Drug Interactions ; Adenosine Diphosphate Ribose/therapeutic use*