Sphingosine-1-phosphate Decreases Erythrocyte Dysfunction Induced by ß-Amyloid.

Amyloid beta peptides (Aß) have been identified as the main pathogenic agents in Alzheimer's disease (AD). Soluble Aß oligomers, rather than monomer or insoluble amyloid fibrils, show red blood cell (RBC) membrane-binding capacity and trigger several morphological and functional alterations in RBCs that can result in impaired oxygen transport and delivery. Since bioactive lipids have been recently proposed as potent protective agents against Aß toxicity, we investigated the role of sphingosine-1-phosphate (S1P) in signaling pathways involved in the mechanism underlying ATP release in Ab-treated RBCs. In RBCs following different treatments, the ATP, 2,3 DPG and cAMP levels and caspase 3 activity were determined by spectrophotometric and immunoassay. S1P rescued the inhibition of ATP release from RBCs triggered by Ab, through a mechanism involving caspase-3 and restoring 2,3 DPG and cAMP levels within the cell. These findings reveal the molecular basis of S1P protection against Aß in RBCs and suggest new therapeutic avenues in AD.

Roles of Erythrocytes in Human Health and Disease 2.0.

This Special Issue titled "Roles of Erythrocytes in Human Health and Disease 2 [...].

The Neuroprotective Potentiality of Flavonoids on Alzheimer's Disease.

Alzheimer's disease (AD), due to its spread, has become a global health priority, and is characterized by senile dementia and progressive disability. The main cause of AD and other neurodegenerations (Huntington, Parkinson, Amyotrophic Lateral Sclerosis) are aggregated protein accumulation and oxidative damage. Recent research on secondary metabolites of plants such as polyphenols demonstrated that they may slow the progression of AD. The flavonoids' mechanism of action in AD involved the inhibition of acetylcholinesterase, butyrylcholinesterase, Tau protein aggregation, ß-secretase, oxidative stress, inflammation, and apoptosis through modulation of signaling pathways which are implicated in cognitive and neuroprotective functions, such as ERK, PI3-kinase/Akt, NFKB, MAPKs, and endogenous antioxidant enzymatic systems. This review focuses on flavonoids and their role in AD, in terms of therapeutic potentiality for human health, antioxidant potential, and specific AD molecular targets.

Psychometric properties and measurement invariance across gender of the Italian version of the tempest self-regulation questionnaire for eating adapted for young adults.

The prevalence of overweight and obesity in young adults has increased dramatically in recent decades. The unhealthy eating habits that develop at this time can often lead to negative health consequences in the future. It is therefore important to learn about self-regulation and self-control strategies and help young adults to have healthy eating behaviours. This study aims to present an Italian version of the Tempest Self-Regulation Questionnaire for Eating (TESQ-E) adapted for young adults. The instrument assesses self-regulation and self-control strategies to counteract the desire and temptation to eat unhealthy food and to choose healthy foods. A total of 645 students (271 males and 374 females with an average age of 24.82 and SD = 4.34) took part in the study. The results of the confirmatory factor analysis supported the six first-order factors model concerning specific self-regulation strategies and a higher-order structure of the TESQ-E [χ2 (152) = 336.480, p < 0.001; CFI = 0.95; RMSEA = 0.04; SRMR = 0.04]: three correlated second-order factors (addressing the temptation directly, addressing the psychological meaning of temptation, and addressing the goal directly) and one-third-order factor (self-regulatory competence). The results also confirmed the strong measurement invariance of the TESQ-E across gender. To have reliable comparisons across males and females, the latent mean differences tests were performed on the six specific self-regulation strategies. The analysis showed that females appear to prefer strategies that directly address the goal by expressing explicit intentions or plans to eat in a healthy way. Convergence validity was tested through correlations with Eating-Self-Efficacy Brief Scale (ESEBS), Emotional Eating Scale (EES), Scale of Attitudes towards Healthy Eating (SAHE), and Body Mass Index (BMI). In conclusion, the TESQ-E appears to be a psychometrically sound questionnaire that can be effectively used with young adults to measure self-regulation strategies in eating in order to plan personalised interventions for the prevention and control of the metabolic syndrome, and to reduce a wide range of diet-related diseases.

The Nutraceuticals as Modern Key to Achieve Erythrocyte Oxidative Stress Fighting in Osteoarthritis.

Osteoarthritis (OA), the most common joint disease, shows an increasing prevalence in the aging population in industrialized countries. OA is characterized by low-grade chronic inflammation, which causes degeneration of all joint tissues, such as articular cartilage, subchondral bone, and synovial membrane, leading to pain and loss of functionality. Erythrocytes, the most abundant blood cells, have as their primary function oxygen transport, which induces reactive oxygen species (ROS) production. For this reason, the erythrocytes have several mechanisms to counteract ROS injuries, which cause damage to lipids and proteins of the cell membrane. Oxidative stress and inflammation are highly correlated and are both causes of joint disorders. In the synovial fluid and blood of osteoarthritis patients, erythrocyte antioxidant enzyme expression is decreased. To date, OA is a non-curable disease, treated mainly with non-steroidal anti-inflammatory drugs and corticosteroids for a prolonged period of time, which cause several side effects; thus, the search for natural remedies with anti-inflammatory and antioxidant activities is always ongoing. In this review, we analyze several manuscripts describing the effect of traditional remedies, such as Harpagophytum procumbens, Curcumin longa, and Boswellia serrata extracts, in the treatments of OA for their anti-inflammatory, analgesic, and antioxidant activity. The effects of such remedies have been studied both in in vitro and in vivo models, considering both joint cells and erythrocytes.

Intention to Screen for Hepatitis C Among University Students: Influence of Different Communicative Scenarios.

This study aimed to evaluate the influence of different narrative scenarios regarding students' intentions to undergo diagnostic screening for hepatitis C, and whether gender identification with the characters of the scenario could influence the students' intentions to undergo a medical test. A sample of 600 participants was administered three narrative scenarios with different frames (positive, negative, and ambivalent), including two gender options (male and female) for the main character of the story. A statistically significant three-way interaction between scenario, gender identification, and time resulted. There were significant simple main effects on the intention to have a diagnostic test for hepatitis C for the scenarios with the protagonist of the same gender as the participant and after the administration of the negative scenario. The use of a negative scenario with the same gender character was always more effective than the use of a positive framed scenario, even though there was a high level of knowledge regarding the disease. Personal diagnostic testing was not directly associated with knowledge regarding the infection. The findings of this study can ultimately help policymakers develop communication campaigns adapted to target populations such as college students, in order to raise awareness of the risk, promote prevention and behavioral change, and encourage medical screening.

ATP release from erythrocytes: A role of adenosine1.

BACKGROUND: The oxygen required to meet metabolic needs of all tissues is delivered by the red blood cell (RBC), a small, flexible cell which, in mammals, is devoid of a nucleus and mitochondria. Despite its simple appearance, this cell has an important role in its own distribution, enabling the delivery of oxygen to precisely meet localized metabolic need. When red blood cells enter in hypoxic area, a signalling pathway is activated within the cell, resulting in the release of ATP in amounts adequate to activate purinergic receptors on vascular endothelium, which trigger secretion of nitric oxide and other factors resulting in vasodilatation. OBJECTIVE: The present study investigates the effect of adenosine exposure on this molecular mechanism. METHODS AND RESULTS: We report that RBC in the presence of adenosine in low oxygen conditions, ATP release increase after 24 h exposure. Adenosine induced-ATP release in deoxygenated red blood cell show data similar to that of RBC in high oxygen conditions: (1) RBC after band 3 modification by 4,4'- diisothio-cyanatostilbene- 2,2'-disulphonic acid; (2) CO-treated RBC. In the presence of Sphingosine kinase (SphK1) inhibitor, adenosine mediated effects on ATP release were abolished. Activity of adenylate cyclase increase following to adenosine exposure, on the contrary red cell phosphofructokinase is not modified within the RBC in the presence of adenosine. CONCLUSION: Our data support involvement of band 3/deoxyHb binding and adenylate cyclase in the pathway responsible for ATP release from RBC following exposure to adenosine.

Amyloid ß peptide affects erythrocyte morphology: Role of intracellular signaling pathways.

BACKGROUND: Circulating red blood cells (RBCs) undergo aging, a fundamental physiological phenomenon that regulates their turnover. OBJECTIVE: Understanding the role of Aß in the cross talk between cell signalling pathways and modulation of the cell structural and biomechanical properties occurring in RBCs during aging. METHODS: The morphological pattern has been monitored using Atomic Force Microscopy (AFM) imaging and measuring the RBCs' plasma membrane roughness employed as a morphological parameter capable to provide information on the structure and integrity of the membrane-skeleton. RESULTS: We show that treatment with Aß accelerates the occurrence of morphological and biochemical aging markers in human RBC and influences the cell metabolism. Biochemical data demonstrate that contemporaneously to morphological alterations, Aß triggers: (i) metabolic alterations and (ii) a complex signaling pathway involving caspase 3, protein kinase C and nitric oxide derived metabolites. CONCLUSIONS: our study provides a comprehensive picture in which Aß treatment of RBC induces changes in specific cell signalling events and/or metabolic pathways, in turns affecting the membrane-cytoskeleton interaction and the membrane integrity.

Morphological changes induced in erythrocyte by amyloid beta peptide and glucose depletion: A combined atomic force microscopy and biochemical study.

Circulating red blood cells (RBCs) undergo aging, a fundamental physiological phenomenon that regulates their turnover. We show that treatment with beta amyloid peptide 1-42 (Aß) accelerates the occurrence of morphological and biochemical aging markers in human RBCs and influences the cell metabolism leading to intracellular ATP depletion. The morphological pattern has been monitored using Atomic Force Microscopy (AFM) imaging and measuring the RBCs' plasma membrane roughness employed as a morphological parameter capable to provide information on the structure and integrity of the membrane-skeleton. Results evidence that Aß boosts the development of crenatures and proto-spicules simultaneously to acceleration in the weakening of the cell-cytoskeleton contacts and to the induction of peculiar nanoscale features on the cell membrane. Incubation in the presence of glucose can remove all but the latter Aß-induced effects. Biochemical data demonstrate that contemporaneously to morphological and structural alterations, Aß and glucose depletion trigger a complex signaling pathway involving caspase 3, protein kinase C (PKC) and nitric oxide derived metabolites. As a whole, the collected data revealed that, the damaging path induced by Aß in RBC provide a sequence of morphological and functional intermediates following one another along RBC life span, including: (i) an acceleration in the development of shape alteration typically observed along the RBC's aging; (ii) the development of characteristic membrane features on the plasma membrane and (iii) triggering a complex signaling pathway involving caspase 3, PKC and nitric oxide derived metabolites.

Erythrocytes as Potential Link between Diabetes and Alzheimer's Disease.

Many studies support the existence of an association between type 2 diabetes (T2DM) and Alzheimer's disease (AD). In AD, in addition to brain, a number of peripheral tissues and cells are affected, including red blood cell (RBC) and because there are currently no reliable diagnostic biomarkers of AD in the blood, a gradually increasing attention has been given to the study of RBC's alterations. Recently it has been evidenced in diabetes, RBC alterations superimposable to the ones occurring in AD RBC. Furthermore, growing evidence suggests that oxidative stress plays a pivotal role in the development of RBC's alterations and vice versa. Once again this represents a further evidence of a shared pathway between AD and T2DM. The present review summarizes the two disorders, highlighting the role of RBC in the postulated common biochemical links, and suggests RBC as a possible target for clinical trials.

Methionine 35 sulphoxide reduces toxicity of Aß in red blood cell.

BACKGROUND: The oxidation of methionine residue in position 35 of Ab to sulphoxide (Ab-sulphoxide) has the ability to deeply modify wild-type Ab 1-42 (Ab) neurotoxic action. Our previous studies suggest that in nucleated cells, lower toxicity of Ab-sulphoxide might result not from structural alteration, but from elevation of methionine sulphoxide reductase A (MsrA) activity and mRNA levels. DESIGN: On this basis, we hypothesised that red blood cell (RBC), a cell devoid almost completely of MsrA activity, shares with nucleated cells an antioxidant system induced by methionine 35 sulphoxide, responsible for the lower toxicity of Ab-sulphoxide in RBC. (Results) Supporting this hypothesis, we found that the low toxicity of Ab-sulphoxide in RBC correlated with pentose phosphate pathway (PPP) flux increase, and this event was associated with a low level of methionine oxidation in total proteins. None of these effects were observed when cells were exposed to Ab native. DISCUSSION: These results outline the importance of the redox state of methionine 35 in the modulation of Ab-mediated events and suggest an important protective role for PPP in RBC of patients affected by Alzheimer's disease.

Vascular dysfunction-associated with Alzheimer's disease.

Our attention is focused on the study of a new model based on the red blood cell (RBC) and on its interaction with amyloid beta peptide 1-42 (Aß). RBC are highly deformable to assist blood flow in the microcirculation. For this reasons RBC abnormalities could contribute to Alzheimer's disease (AD) by obstructing oxygen delivery to brain, causing hypoxia. In our work, considering that RBC membrane contains, among blood elements, higher acetylcholinesterase (AChE) levels, we can assume that in blood occurs a mechanism similar to the one which occurs at the neuronal level leading to an increase of Aß toxicity mediated by its binding with AChE, located on the RBC external face. Furthermore, since mechanical properties of RBC membrane are regulated by a number of molecular components of signalling and/or regulatory pathways, of these, particular interest has been addressed toward Nitric Oxide (NO) metabolism, due to its dependence to AChE.

Involvement of acetylcholinesterase and protein kinase C in the protective effect of caffeine against ß-amyloid-induced alterations in red blood cells.

It is well known the role of oxidative stress in the pathophysiology of Alzheimer's disease (AD) and of other neurodegenerative pathologies. We have previously documented that Amyloid beta peptide (1-42) (Abeta) dependent-oxidative modifications affect red blood cell (RBC) morphology and function. Experimental studies show that caffeine (CF) consumption is inversely correlated with AD. In this study, we investigated the role played by RBC in the protective mechanism elicited by CF against Abeta mediated toxicity. PS exposure levels by FACS analysis, as well as protein band 3 functionality analysis, indicated that CF at 100 µM protected against Abeta-mediated membrane alterations, which are known to occur in AD. Moreover, CF counteracts inhibition of ATP release from RBC by Abeta, restoring its ability to modulate vasodilation. Concurrently, analysis of protein kinase C (PKC) and caspase 3 activities, responsible for cytoskeleton alterations, revealed that unlike to caspase 3, PKCα activation induced by Abeta was fully abolished by CF through a mechanism involving Acetylcholinesterase (AChE), located on external face of RBC plasma membrane. These results provide support for the hypothesis concerning the protective role of CF in AD patients could include also a peripheral mechanism involving RBC.

Amyloid beta peptide (1-42)-mediated antioxidant imbalance is associated with activation of protein kinase C in red blood cells.

Glycolysis and pentose phosphate pathway (PPP) in red blood cell (RBC) are modulated by the cell oxygenation state. This metabolic modulation is connected to variations in intracellular nicotinamide adenine dinucleotide phosphate-reduced form (NADPH) and adenosine triphosphate (ATP) levels as a function of the oxygenation state of the cell, and, consequently, it should have physiologic relevance. In the present study, we analysed the effects of amyloid beta peptide (1-42) (Abeta) on RBC metabolism and its relationship with the activity of protein kinase C (PKC). Our results showed that metabolic response to Abeta depended on the degree of cell oxygenation. In particular, under high O2 pressure, in Abeta-treated RBC, glucose metabolized through PPP approached that metabolized by RBC under low O2 pressure, differently to that observed in untreated cells. The effect of Abeta on RBC metabolism was paralleled by increase in PKC enzyme activity, but cytosolic Ca2+ concentration does not seem to be involved in this mechanism. Incubation of Abeta-treated RBC with a specific inhibitor of PKC partially restores PPP flux. A possible rationalization of the different metabolic behaviours shown by RBC following Abeta treatment is proposed. It takes into account the known post-translational modifications to cytoskeleton proteins induced by PKC. The reduction in PPP flux may lead to a weakened defence system of antioxidant reserve in RBC, becoming a source of reactive species, and, consequently, its typical, structural and functional features are lost. Therefore, oxidative stress may outflow from the RBC and trigger damage events in adjacent cells and tissue, thus contributing to vascular damage.

Protein kinase C mediates caspase 3 activation: A role for erythrocyte morphology changes.

We have previously showed that morphological alterations in Red Blood Cells (RBCs) are correlated to an impaired eNOS enzymatic activity and a concomitant reduced NO derived metabolites formation. Here we extend our previous observations, reporting that RBC morphology is regulated by a series of specific cell signaling events linked to Protein Kinase C (PKC)-mediated activation of caspase 3. Pretreatment of RBCs with the PKC inhibitor chelerythrine, prior to the addition of phorbol-12-myristate-13-acetate (PMA), an activator of PKC, blocks the appearance of the morphology alterations and the sustained decrease in nitrates and nitrites levels induced by PMA. Inhibition of PKC also completely inhibits PMA mediated caspase-3 activation. On the other hand, caspase 3 inhibition, lessens the PMA induced-effects on the appearance of RBC morphology alterations, although it enhances PMA-mediated effects on nitric oxide (NO) derived metabolites levels. These data demonstrate that PKC-mediated activation of caspase 3 is an integral and essential part of signaling pathway in RBCs, that may be a regulatory factor of RBC mechanical properties, through regulation of NO metabolism.

NO Metabolites Levels in Human Red Blood Cells are Affected by Palytoxin, an Inhibitor of Na(+)/K(+)-ATPase Pump.

Palytoxin (PTX), a marine toxin, represents an increasing hazard for human health. Despite its high toxicity for biological systems, the mechanisms triggered by PTX, are not well understood. The high affinity of PTX for erythrocyte Na(+)/K(+)-ATPase pump is largely known, and it indicates PTX as a sensitive tool to characterize the signal transducer role for Na(+)/K(+)-ATPase pump. Previously, it has been reported that in red blood cells (RBC), probably via a signal transduction generated by the formation of a PTX-Na(+)/K(+)-ATPase complex, PTX alters band 3 functions and glucose metabolism. The present study addresses the question of which other signaling pathways are regulated by Na(+)/K(+)-ATPase in RBC. Here it has been evidenced that PTX following its interaction with Na(+)/K(+)-ATPase pump, alters RBC morphology and this event is correlated to decreases by 30% in nitrites and nitrates levels, known as markers of plasma membrane eNOS activity. Orthovanadate (OV), an antagonist of PTX binding to Na(+)/K(+)-ATPase pump, was able to reverse the effects elicited by PTX. Finally, current investigation firstly suggests that Na(+)/K(+)-ATPase pump, following its interaction with PTX, triggers a signal transduction involved in NO metabolism regulation.

Antiepileptic carbamazepine drug treatment induces alteration of membrane in red blood cells: possible positive effects on metabolism and oxidative stress.

Carbamazepine (CBZ) is an iminostilbene derivative commonly used for treatment of neuralgic pain and bipolar affective disorders. CBZ blood levels of treated patients are within the range of micromolar concentrations and therefore, significant interactions of this drug with erythrocytes are very likely. Moreover, the lipid domains of the cell membrane are believed to be one of the sites where iminostilbene derivatives exert their effects. The present study aimed to deeply characterize CBZ effects on erythrocytes, in order to identify extra and/or cytosolic cell targets. Our results indicate that erythrocyte morphological changes promoted by the drug, may be triggered by an alteration in band 3 functionality i.e. at the level of anionic flux. In addition, from a metabolic point of view this perturbation could be considered, at least in part, as a beneficial event because it could favour the CO2 elimination. Since lipid peroxidation, superoxide and free radical scavenging activities, caspase 3 activity and hemoglobin (Hb) functionality were not modified within the CBZ treated red blood cell (RBC), band 3 protein (B3) may well be a specific membrane target for CBZ and responsible for CBZ-induced toxic effects in erythrocytes. However some beneficial effects of this drug have been evidenced; among them an increased release of ATP and nitric oxide (NO) derived metabolites from erythrocytes to lumen, leading to an increased NO pool in the vasculature. In conclusion, these results indicate that CBZ, though considered responsible for toxic effects on erythrocytes, can also exhibit effects that at least in some conditions may be seen as beneficial.

ß-amyloid decreases detectable endothelial nitric oxide synthase in human erythrocytes: a role for membrane acetylcholinesterase.

Until few years ago, many studies of Alzheimer's disease investigated the effects of this syndrome in the central nervous system. Only recently, the detection of amyloid beta peptide (Aß) in the blood has evidenced the necessity to extend studies on extraneuronal cells, particularly on erythrocytes. Aß is also present in brain capillaries, where it interacts with the erythrocytes, inducing several metabolic and functional alterations. Recently, functionally active endothelial type nitric oxide synthase (eNOS) was discovered in human erythrocytes. The goal of the present study was to evidence the effect of Aß on erythrocyte eNOS. We found that Aß following to 24-h exposure causes a decrease in the immune staining of erythrocyte eNOS. Concurrently, Aß alters erythrocyte cell morphology, decreases nitrites and nitrates levels, and affects membrane acetylcholinesterase activity. Propidium, an acetylcholinesterase inhibitor, was able to reverse the effects elicited by Aß. These events could contribute to the vascular alterations associated with Alzheimer's disease disease.