title: Nitric oxide synthetic pathway and cGMP levels are altered in red blood cells from end-stage renal disease patients.
abstract: Red blood cells (RBCs) enzymatically produce nitric oxide (NO) by a functional RBC-nitric oxide synthase (RBC-NOS). NO is a vascular key regulatory molecule. In RBCs its generation is complex and influenced by several factors, including insulin, acetylcholine, and calcium. NO availability is reduced in end-stage renal disease (ESRD) and associated with endothelial dysfunction. We previously demonstrated that, through increased phosphatidylserine membrane exposure, ESRD-RBCs augmented their adhesion to human cultured endothelium, in which NO bioavailability decreased. Since RBC-NOS-dependent NO production in ESRD is unknown, this study aimed to investigate RBC-NOS levels/activation, NO production/bioavailability in RBCs from healthy control subjects (C, N = 18) and ESRD patients (N = 27). Although RBC-NOS expression was lower in ESRD-RBCs, NO, cyclic guanosine monophosphate (cGMP), RBC-NOS Serine1177 phosphorylation level and eNOS/Calmodulin (CaM)/Heat Shock Protein-90 (HSP90) interaction levels were higher in ESRD-RBCs, indicating increased enzyme activation. Conversely, following RBCs stimulation with insulin or ionomycin, NO and cGMP levels were significantly lower in ESRD- than in C-RBCs, suggesting that uremia might reduce the RBC-NOS response to further stimuli. Additionally, the activity of multidrug-resistance-associated protein-4 (MRP4; cGMP-membrane transporter) was significantly lower in ESRD-RBCs, suggesting a possible compromised efflux of cGMP across the ESRD-RBCs membrane. This study for the first time showed highest basal RBC-NOS activation in ESRD-RBCs, possibly to reduce the negative impact of decreased NOS expression. It is further conceivable that high NO production only partially affects cell function of ESRD-RBCs maybe because in vivo they are unable to respond to physiologic stimuli, such as calcium and/or insulin.
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.|Aging Research Center and Translational Medicine CeSI-MeT, "G. d'Annunzio" University Foundation, Chieti-Pescara, Room 421, Via Luigi Polacchi, 11, 66100, Chieti, Italy.
authors.forename: Natalia
authors.initials: N
authors.lastname: Di Pietro
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.|Aging Research Center and Translational Medicine CeSI-MeT, "G. d'Annunzio" University Foundation, Chieti-Pescara, Room 421, Via Luigi Polacchi, 11, 66100, Chieti, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Giardinelli
authors.affiliation: Department of Medicine and Aging Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Sirolli
authors.affiliation: Department of Oncology, University of Torino, Turin, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Riganti
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.|Aging Research Center and Translational Medicine CeSI-MeT, "G. d'Annunzio" University Foundation, Chieti-Pescara, Room 421, Via Luigi Polacchi, 11, 66100, Chieti, Italy.
authors.forename: Pamela
authors.initials: P
authors.lastname: Di Tomo
authors.affiliation: Department of Oncology, University of Torino, Turin, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Gazzano
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.|Aging Research Center and Translational Medicine CeSI-MeT, "G. d'Annunzio" University Foundation, Chieti-Pescara, Room 421, Via Luigi Polacchi, 11, 66100, Chieti, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Di Silvestre
authors.affiliation: Cardiovascular Research Laboratory, Division of Cardiology, Pneumology and Angiology, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Panknin
authors.affiliation: Cardiovascular Research Laboratory, Division of Cardiology, Pneumology and Angiology, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Miriam M
authors.initials: MM
authors.lastname: Cortese-Krott
authors.affiliation: Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Szeged, Hungary.|Pharmahungary Group, Szeged, Hungary.
authors.forename: Csaba
authors.initials: C
authors.lastname: Csonka
authors.affiliation: Cardiovascular Research Laboratory, Division of Cardiology, Pneumology and Angiology, Medical Faculty, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Kelm
authors.affiliation: Pharmahungary Group, Szeged, Hungary.|Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Ferdinandy
authors.affiliation: Department of Medicine and Aging Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Bonomini
authors.affiliation: Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", Chieti-Pescara, Chieti, Italy. pandolfi@unich.it.|Aging Research Center and Translational Medicine CeSI-MeT, "G. d'Annunzio" University Foundation, Chieti-Pescara, Room 421, Via Luigi Polacchi, 11, 66100, Chieti, Italy. pandolfi@unich.it.
authors.forename: Assunta
authors.initials: A
authors.lastname: Pandolfi
mesh_terms: D000368:Aged; D002147:Calmodulin / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism* / Q000473:pathology; D005260:Female; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis; D009569:Nitric Oxide / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism
chemical_list: D002147:Calmodulin; D006152:Cyclic GMP; D018841:HSP90 Heat-Shock Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C073492:ABCC4 protein, human; C496314:NOS3 protein, human
keywords: End-stage renal disease; Nitric oxide; Nitric oxide synthase; Red blood cells; cGMP