An overview about erythrocyte membrane

© 2010 – IOS Press and the authors. All rights reservedIn the sixties and seventies, erythrocytes or red blood cells (RBCs) were extensively studied. Much has been learnt particularly concerning their metabolism and gas transporter function. In the past decade, the use of new approaches and methodologies, such as proteomic analysis, has contributed for a renewed interest on the erythrocyte. Recent studies have provided us with a more detailed and comprehensive picture on the composition and organization of its cellular membrane that will be the main subject of this minireview. Unexpectedly, it has been recognized that this cell expresses several adhesion molecules on its surface, like other cellular types such blood circulating cells or endothelial cells. Taking into consideration the cellular functions of the erythrocyte, the clarification of the role of those adhesion molecules may in the future open new horizons for the biological significance of this cellular player.Fundação para a Ciência e Tecnologia (FCT) for the financial support(PTDC/SAU-OSM/73449/2006)

Erythrocyte a target for Covid-19 infected patients

Copyright@ Carlota Saldanha. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use and redistribution provided that the original author and source are credited.The questions about the Covid-2 and the discussion of the answers are the aim of the present opinion. Facing the great amount of knowledge centered in the field of red blood cells (RBC) or erythrocyte arise the principle for a diagnostic test with efficiency, accuracy, fast and cheap in order to differentiate the infected Covid-19 patients from those that are asymptomatic but with or without the Covid-19. Different results may be obtained and will be here discussed. The signal transduction mechanisms of nitric oxide in the RBC have key points that are therapeutic targets for compounds to apply in infected Covid-19 patients.info:eu-repo/semantics/publishedVersio

Therapeutic approach for Covid-19 patients

Copyright © All rights are reserved by Carlota Saldanha. This work is licensed under Creative Commons Attribution 4.0 LicenseThe biochemical effects of hydroxychloroquine, ivermectin, azithromycin molecules, and the zinc cation on functional properties of human erythrocyte will be presented. Among a wide range of therapeutically applications attributed to hydroxycloroquine the anti-inflammatory role will be herein highlight as well as for the azithromycin. The intervention of the ivermectin molecules into cell abortion mechanism of the virus replication will be described. The action of hydroxychloroquine, ivermectin, azithromycin molecules, and of zinc cation to prevent the spread and the replication SARS2-CoV2 Virus, as a first therapeutic approach for Covid-19 symptomatic patients, will be the aim of the present opinion.info:eu-repo/semantics/publishedVersio

Erythrocyte Nitric Oxide

Nitric oxide (NO) is a vasoactive molecule that, by stimulated and functional vascular endothelial cells, is released to the lumen of the vessel and into the surrounding smooth muscle cells. Once in the lumen, NO is captured by red blood cells and scavenged inside through hemoglobin and derived as NO metabolites. The delivery ability of erythrocytes allowing the NO efflux also occurs. Manipulation of NO levels inside the erythrocyte through different external (acetylcholine, acetylcholinesterase inhibitors, fibrinogen and CD47 4N1K peptide) and internal (redox and protein phosphorylation levels) stimuli will be described. The values of NO efflux from the erythrocytes and its association with the data quantified in the hemorheology properties and in clinical parameters obtained from patients with vascular diseases will also be present. The in vivo animal experimental studies highlighting the ability of NO efflux (delivered) from the erythrocytes where is scavenged and its influence in inflammatory and hemorheological responses will be addressed. So, the aim of this chapter is to present the knowledge obtained about the NO signal transduction mechanism in erythrocytes and the association between erythrocyte availability in NO with clinical biomarkers obtained in inflammatory vascular diseases. A final question is raised—namely, could NO be considered a hemorheological parameter

Human erythrocyte acetylcholinesterase in health and disease

© 2017 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).The biochemical properties of erythrocyte or human red blood cell (RBC) membrane acetylcholinesterase (AChE) and its applications on laboratory class and on research are reviewed. Evidence of the biochemical and the pathophysiological properties like the association between the RBC AChE enzyme activity and the clinical and biophysical parameters implicated in several diseases are overviewed, and the achievement of RBC AChE as a biomarker and as a prognostic factor are presented. Beyond its function as an enzyme, a special focus is highlighted in this review for a new function of the RBC AChE, namely a component of the signal transduction pathway of nitric oxide.This work was funded by Fundação para a Ciência e Tecnologia: LISBOA-01-0145-FEDER-007391, project cofunded by FEDER, through POR Lisboa 2020—Programa Operacional Regional de Lisboa, PORTUGAL 2020.info:eu-repo/semantics/publishedVersio

Erythrocyte reactive nitrogen species in health and disease

Copyright: © 2018 Saldanha C. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.In general, reactive nitrogen species, like nitric oxide (NO) and peroxynitrite are classified in primary and secondary according its benefic or deleterious effects respectively. Multiple benefic roles through the body has been attributed to nitric oxide (NO), a key signaling molecule, which acts as vasodilator relaxing smooth muscles of arteries; participates in the blood pressure control; hinders the initiation of inflammation NO liberated from endothelium cells or lymphocytes to intravascular corporal fluid enter into erythrocytes through membrane band 3 protein being after captured by deoxyhemoglobin or by oxyhemoglobin. Inside the erythrocytes several chemical reactions occur with generation of S-nitrosoglutathione a NO reservoir molecules and NO derivatives (NOx) molecules namely nitrite, nitrate and peroxynitrite. The erythrocyte acts as sensor of the tissues oxygen partial pressure and consequently change its oxygen levels lead along with NO contents. NO is released through band 3 protein into the blood, at microcirculatory network, in tissues with low oxygen partial pressure. The aim of this mini review was to present the erythrocyte signal transduction pathways associated with NO and S-nitrosoglutathione efflux, metabolic behavior of the NO reservoir molecules and NO reactive species in human erythrocytes under several biological conditions. For examples, the effects of external amphipathic molecules, fibrinogen, and internal manipulation of protein phosphorylation degree and redox status on erythrocyte. NOx, NO and S-nitrosoglutathione efflux levels are herein included. Erythrocyte NO efflux evidenced as biomarkers of inflammatory vascular diseases will be herein highlighted.This work was funded by Fundação para a Ciência e Tecnologia: LISBOA-01-0145-FEDER-007391, project cofunded by FEDER, through POR Lisboa 2020 - Programa Operacional Regional de Lisboa, PORTUGAL 2020.info:eu-repo/semantics/publishedVersio

Sepsis needs follow-up studies in intensive care units : another avenue for translational research

© All rights are reserved by Carlota SaldanhaSepsis characteristics were highlight in this mini review in order to call attention for a complex, age- independent, acute disease faced suddenly by the human body under infection or traumatic stimuli. It may follow surgical intervention, traumatic accident or exposure to an infectious agent. Timely diagnosis and accurate stratification of the severity of sepsis are needed to understand the molecular mechanisms involved in this pathophysiology and reduce mortality. In order to obtain these achievements follow-up studies need to be conducted in intensive care units under translational research.info:eu-repo/semantics/publishedVersio

Effects of acetylcholine and SpermineNONOate on erythrocyte hemorheologic and oxygen carrying properties

© 2001 – IOS Press. All rights reservedPurpose of the study: To determine the effects of acetylcholine and SpermineNONOate – a NO donor – on RBC membrane and oxygen carrying properties. Material and methods: Aliquots of venous blood from eleven heathy subjects were incubated with ACh 10−3 M, ACh 10−5 M, SpermineNONOate 10−5 M and SpermineNONOate 10−4 M. The following parameters were determined: erythrocyte aggregation and deformability, hematocrit, plasma pH, osmolality, K+, Na+, Ca2+ concentrations, hemoglobin, oxyhemoglobin, carboxihemoglobin and methemoglobin concentrations, oxygen saturation of hemoglobin, oxygen and carbon dioxide parcial pressures and p50. Results: In presence of ACh there is an increase of erythrocyte deformability, decrease of erythrocyte aggregation, plasma pH, K+ and Na+ concentration, increase of Ca2+ concentration and p50. In presence of SpermineNONOate there an increase of erythrocyte deformability, plasma pH, decrease of Na+ and Ca2+ concentration, increase of metHb concentration and decrease of p50. Conclusion: Acetylcholine and SpermineNONOate are able to induce changes on RBC membrane and oxygen carrying properties

Modulation of erythrocyte hemorheological properties by band 3 phosphorylation and dephosphorylation

© 2007 – IOS Press and the authors. All rights reservedThe objective of the present work was to study the effects of erythrocyte proteins phosphorylation in erythrocyte aggregation and deformability. Human whole blood samples were incubated in vitro in absent and in presence of the phosphorylation/dephosphorilation band 3 inhibitors and also with adenylyl cyclase, guanylate cyclase and PI3K inhibitors and the erythrocyte aggregation index (EAI) and deformability were assayed. The results show that when band 3 is phosphorylated in presence of a PTP inhibitor an increase in erythrocyte aggregation index is observed (p < 0.0001). A partial dephosphorylation band 3 state, induced by PTK inhibitors, show a decrease in the erythrocyte aggregation index (p < 0.002). However both manipulated states induced lower EAI values than blood samples aliquots controls. The guanylate cyclase and PI3-K inhibitors significantly decrease the erythrocyte aggregation index in relation with the control blood samples. Erythrocyte deformability in presence of all the inhibitors did not showed significant changes. PTP and PI3-K inhibitors showed a significantly increase in the plasma potassium concentrations not associated with EAI values. Methehemoglobin levels were increased significantly when guanylate cyclase inhibitor is present in the blood samples. In conclusion, the results suggest that erythrocyte aggregation index is dependent of the phosphorylated/dephosphorylated state of band 3

Erythrocyte acetylcholinesterase is a signaling receptor

© All rights are reserved by Carlota SaldanhaThe acetylcholinesterase (AChE), is an enzyme located in the erythrocyte membrane that motivate continually questions, about its physiological function. The aim of this mini review is highlight the receptor behavior of AChE in human red blood cells for chemical signals associated with nitric oxide mobilization and efflux from erythrocytes. Data from the experimental models used are presented. Consequently, key participative proteins in the steps of the signal transduction pathways, in dependence of AChE receptor, are suggested to be further considered as potential therapeutic targets.This work was funded by Fundação para a Ciência e Tecnologia: LISBOA-01-0145-FEDER-007391, project cofunded by FEDER, through POR Lisboa 2020 - Programa Operacional Regional de Lisboa, Portugal 2020.info:eu-repo/semantics/publishedVersio