Altered Red Blood Cell Research Articles

Sex-Specific Differences of Adenosine Triphosphate Levels in Red Blood Cells Isolated From ApoE/LDLR Double-Deficient Mice

In this study for the first time, we investigated the correlation between sex-specific differences in adenosine triphosphate (ATP) levels in red blood cells (RBCs) and their mechanical, biochemical, and morphological alterations during the progression of atherosclerosis in ApoE/LDLR double-deficient (ApoE/LDLR−/−) mice. Our results indicate that both sex and age affect alterations in RBCs of both ApoE/LDLR−/− and C57BL/6J mice. When compared with male RBCs, female RBCs were characterized by lower basal ATP and mean corpuscular hemoglobin concentration (MCHC), higher hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), deformability, and phosphatidylserine (PS) exposure levels, regardless of age in both, ApoE/LDLR−/− and C57BL/6J mice. ApoE/LDLR−/− mice compared with age-matched controls showed lower basal ATP levels regardless of age and sex. Intracellular ATP level of RBCs was decreased solely in senescent female C57BL/6J mice, while it was elevated in males. Basal extracellular ATP levels were 400 times lower than corresponding intracellular level. In conclusion, basal ATP levels, RBC morphology, deformability, PS exposure levels alterations are sex-dependent in mice. Changes in basal ATP levels were correlated with PS exposure and trends of changes in MCV. Trends of changes of the most RBC parameters were similar in both sexes of ApoE/LDLR−/− mice compared with age-matched controls; however, their kinetics and levels vary greatly between different stages of disease progression.

Red Blood Cell Morphodynamics in Patients with Polycythemia Vera and Stroke.

Polycythemia vera (PV) is a Ph-negative myeloproliferative neoplasm (MPN) which is characterized by erythrocytosis and a high incidence of thrombotic complications, including stroke. The study aimed to evaluate red blood cell (RBC) morphodynamic properties in PV patients and their possible association with stroke. We enrolled 48 patients with PV in this cross-sectional study, 13 of which have a history of ischemic stroke. The control group consisted of 90 healthy subjects. RBC deformability and aggregation analysis were performed using a laser-assisted optical rotational red cell analyzer. The following parameters were calculated: aggregation amplitude (Amp), RBC rouleaux formation time constant (Tf), time of formation of three-dimensional aggregates (Ts), aggregation index (AI), rate of complete disaggregation (y-dis), and the maximal elongation of RBC (EImax). Statistical analysis was performed with the R programming language. There were significant differences in RBCs morphodynamics features between patients with PV and the control group. Lower EImax (0.47 (0.44; 0.51) vs. 0.51 (0.47; 0.54), p < 0.001) and γ-dis (100 (100; 140) vs. 140 (106; 188) s−1, p < 0.001) along with higher amplitude (10.1 (8.6; 12.2) vs. 7.7 (6.6; 9.2), p < 0.001) was seen in patients with PV compared with control. A statistically significant difference between PV patients with and without stroke in aggregation amplitude was found (p = 0.03). A logistic regression model for stroke was built based on RBC morphodynamics which performed reasonably well (p = 0.01). RBC alterations may be associated with overt cerebrovascular disease in PV, suggesting a possible link between erythrocyte morphodynamics and increased risk of stroke.

Dietary alpha‐linolenic acid reduces platelet activation and collagen‐mediated cell adhesion in sickle cell disease mice

BackgroundSickle cell disease (SCD) is a genetic hemoglobinopathy associated with high morbidity and mortality. The primary cause of hospitalization in SCD is vaso‐occlusive crisis (VOC), mediated by alteration of red blood cells, platelets, immune cells and a pro‐adhesive endothelium. ObjectivesWe investigated the potential therapeutic use of the plant‐derived omega‐3 alpha‐linolenic acid (ALA) in SCD. MethodsBerkeley mice were fed a low‐ or high‐ALA diet for 4 weeks, followed by analysis of liver fibrosis, endothelial activation, platelet activation and formation of platelet‐neutrophils aggregates. Aggregation of platelets over collagen under flow after high‐ALA was compared to a blocking P‐selectin Fab. ResultsDietary high‐ALA was able to reduce the number of sickle cells in blood smear, liver fibrosis, and the expression of adhesion molecules on the endothelium of aorta, lungs, liver and kidneys (VCAM‐1, ICAM‐1 and vWF). Specific parameters of platelet activation were blunted after high‐ALA feeding, notably P‐selectin exposure and the formation of neutrophil‐platelet aggregates, along with a correspondingly reduced expression of PSGL‐1 on neutrophils. By comparison, in vivo treatment of SCD mice with the anti‐P‐selectin Fab was able to similarly reduce the formation of neutrophil‐platelet aggregates, but did not reduce GpIbα shedding nor the activation of the αIIbβ3 integrin in response to thrombin. Both ALA feeding and P‐selectin blocking significantly reduced collagen‐mediated cell adhesion under flow. ConclusionsDietary ALA is able to reduce the pro‐inflammatory and pro‐thrombotic state occurring in the SCD mouse model and may represent a novel, inexpensive and readily available therapeutic strategy for SCD.

Multiscale computational framework for predicting viscoelasticity of red blood cells in aging and mechanical fatigue

Red blood cells (RBCs) experience significant cyclic deformation through large elastic stretching and relaxation as they circulate in the bloodstream. Such hundreds of thousands times cell deformation causes cumulative fatigue damage to the circulating RBCs, leading to alterations in cell deformability and membrane viscoelasticity. Here, we employ a two-step multiscale computational framework based on coarse-grained molecular dynamics (CGMD) and dissipative particle dynamics (DPD) to probe the viscoelastic properties of the surface-altered RBCs in aging and mechanical fatigue, using experimental information on the molecular structures of both RBC membrane and cytosolic Hb as well as Hb concentration of RBC cytosol. We perform CGMD simulations to compute the shear modulus and membrane viscosity of a small RBC patch with altered horizontal connectivity within spectrin network; meanwhile, we compute the shear viscosity of RBC cytosol under different Hb concentrations. We then use these computed parameters as inputs for a more coarse-grained DPD-based RBC model at the whole-cell level to probe cell deformation, dynamic relaxation, viscoelastic performance of the altered RBC membrane. We find that the RBC membrane rigidity increases with the enhanced horizontal connectivity within spectrin network, but by a factor less than the effective membrane viscosity, resulting in an elevated characteristic relaxation time with increasing fatigue cycles. In addition, we quantify the two-dimensional storage and loss moduli of RBC membrane under time-dependent loading, revealing that the loss modulus is much larger than the storage modulus throughout the entire frequency range covered by the simulations, especially under enhanced connectivity in the cytoskeletal network, which is analogous to the performance of typical viscoelastic materials. These quantitative findings provide unique insights into the progressive damage of circulating RBCs, and demonstrate the capability of the two-step multiscale framework in effectively predicting the altered viscoelastic properties of RBCs influenced by in vivo aging and mechanical fatigue.

Metabolic Influences Modulating Erythrocyte Deformability and Eryptosis.

Many factors in the surrounding environment have been reported to influence erythrocyte deformability. It is likely that some influences represent reversible changes in erythrocyte rigidity that may be involved in physiological regulation, while others represent the early stages of eryptosis, i.e., the red cell self-programmed death. For example, erythrocyte rigidification during exercise is probably a reversible physiological mechanism, while the alterations of red blood cells (RBCs) observed in pathological conditions (inflammation, type 2 diabetes, and sickle-cell disease) are more likely to lead to eryptosis. The splenic clearance of rigid erythrocytes is the major regulator of RBC deformability. The physicochemical characteristics of the surrounding environment (thermal injury, pH, osmolality, oxidative stress, and plasma protein profile) also play a major role. However, there are many other factors that influence RBC deformability and eryptosis. In this comprehensive review, we discuss the various elements and circulating molecules that might influence RBCs and modify their deformability: purinergic signaling, gasotransmitters such as nitric oxide (NO), divalent cations (magnesium, zinc, and Fe2+), lactate, ketone bodies, blood lipids, and several circulating hormones. Meal composition (caloric and carbohydrate intake) also modifies RBC deformability. Therefore, RBC deformability appears to be under the influence of many factors. This suggests that several homeostatic regulatory loops adapt the red cell rigidity to the physiological conditions in order to cope with the need for oxygen or fuel delivery to tissues. Furthermore, many conditions appear to irreversibly damage red cells, resulting in their destruction and removal from the blood. These two categories of modifications to erythrocyte deformability should thus be differentiated.

Endometriosis Susceptibility to Dapsone-Hydroxylamine-Induced Alterations Can Be Prevented by Licorice Intake: In Vivo and In Vitro Study.

Endometriosis, an estrogen-dependent chronic gynecological disease, is characterized by a systemic inflammation that affects circulating red blood cells (RBC), by reducing anti-oxidant defenses. The aim of this study was to investigate the potential beneficial effects of licorice intake to protect RBCs from dapsone hydroxylamine (DDS-NHOH), a harmful metabolite of dapsone, commonly used in the treatment of many diseases. A control group (CG, n = 12) and a patient group (PG, n = 18) were treated with licorice extract (25 mg/day), for a week. Blood samples before (T0) and after (T1) treatment were analyzed for: i) band 3 tyrosine phosphorylation and high molecular weight aggregates; and ii) glutathionylation and carbonic anhydrase activity, in the presence or absence of adjunctive oxidative stress induced by DDS-NHOH. Results were correlated with plasma glycyrrhetinic acid (GA) concentrations, measured by HPLC–MS. Results showed that licorice intake decreased the level of DDS-NHOH-related oxidative alterations in RBCs, and the reduction was directly correlated with plasma GA concentration. In conclusion, in PG, the inability to counteract oxidative stress is a serious concern in the evaluation of therapeutic approaches. GA, by protecting RBC from oxidative assault, as in dapsone therapy, might be considered as a new potential tool for preventing further switching into severe endometriosis.

Do We Store Packed Red Blood Cells under "Quasi-Diabetic" Conditions?

Red blood cell (RBC) transfusion is one of the most common therapeutic procedures in modern medicine. Although frequently lifesaving, it often has deleterious side effects. RBC quality is one of the critical factors for transfusion efficacy and safety. The role of various factors in the cells’ ability to maintain their functionality during storage is widely discussed in professional literature. Thus, the extra- and intracellular factors inducing an accelerated RBC aging need to be identified and therapeutically modified. Despite the extensively studied in vivo effect of chronic hyperglycemia on RBC hemodynamic and metabolic properties, as well as on their lifespan, only limited attention has been directed at the high sugar concentration in RBCs storage media, a possible cause of damage to red blood cells. This mini-review aims to compare the biophysical and biochemical changes observed in the red blood cells during cold storage and in patients with non-insulin-dependent diabetes mellitus (NIDDM). Given the well-described corresponding RBC alterations in NIDDM and during cold storage, we may regard the stored (especially long-stored) RBCs as “quasi-diabetic”. Keeping in mind that these RBC modifications may be crucial for the initial steps of microvascular pathogenesis, suitable preventive care for the transfused patients should be considered. We hope that our hypothesis will stimulate targeted experimental research to establish a relationship between a high sugar concentration in a storage medium and a deterioration in cells’ functional properties during storage.

Changes in Human Erythrocyte Exposed to Organophosphate Flame Retardants: Tris(2-chloroethyl) Phosphate and Tris(1-chloro-2-propyl) Phosphate.

Tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propyl) phosphate (TCPP) are the main representatives of organophosphate flame retardants (OPFRs). The exposure of humans to OPFRs present in air, water, and food leads to their occurrence in the circulation. Thus far, no report has been published about the influence of these retardants on non-nucleated cells like mature erythrocytes. Therefore, the impact of TCEP and TCPP (in concentrations determined in human blood as well as potentially present in the human body after intoxication) on human erythrocytes was evaluated. In this study, the effect of TCEP and TCPP on the levels of methemoglobin, reduced glutathione (GHS), and reactive oxygen species (ROS), as well as the activity of antioxidative enzymes, was assessed. Moreover, morphological, hemolytic, and apoptotic alterations in red blood cells were examined. Erythrocytes were incubated for 24 h with retardants in concentrations ranging from 0.001 to 1000 μg/mL. This study has revealed that the tested flame retardants only in very high concentrations disturbed redox balance; increased ROS and methemoglobin levels; and induced morphological changes, hemolysis, and eryptosis in the studied cells. The tested compounds have not changed the activity of the antioxidative system in erythrocytes. TCPP exhibited a stronger oxidative, eryptotic, and hemolytic potential than TCEP in human red blood cells. Comparison of these findings with hitherto published data confirms a much lower toxicity of OPFRs in comparison with brominated flame retardants.

Storage-Related Changes in Autologous Whole Blood and Irradiated Allogeneic Red Blood Cells and Their Ex Vivo Effects on Deformability, Indices, and Density of Circulating Erythrocytes in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass

Blood-processing techniques and preservation conditions cause storage lesions, possibly leading to adverse outcomes after transfusion. The authors investigated the metabolic changes and deformability of red blood cells (RBCs) during storage and determined the effect of storage lesions on circulating RBCs during cardiac surgery. Prospective study. Tertiary care center affiliated with a university hospital. Adults who underwent elective cardiac surgery requiring cardiopulmonary bypass. The authors collected aliquots of autologous and irradiated allogeneic RBCs and blood samples from seven patients who received autologous whole blood and nine patients who received irradiated allogeneic RBCs before incision (baseline), at the start and end of cardiopulmonary bypass, and at completion of surgery. The authors analyzed RBC deformability, erythrocyte indices, and density distribution to evaluate blood banking-induced alterations of autologous and allogeneic RBCs and changes in circulating RBCs in recipients, after blood transfusion. Time-dependent biochemical changes and significant decreases in deformability during storage occurred in both groups; however, homologous RBCs had significantly lower deformability than autologous RBCs. Trends in mean corpuscular volume and mean corpuscular hemoglobin concentration differed in both groups. In the homologous transfusion group, during cardiac surgery, RBC deformability, mean corpuscular volume, and mean corpuscular hemoglobin concentration showed significant changes compared with baseline values, and a greater number of denser subpopulations was observed at surgery completion. Blood-processing techniques contribute to storage lesions, suggesting that transfusion of autologous whole blood, rather than allogeneic RBCs, could maintain the ability of circulating RBCs to deform and lead to potentially better transfusion outcomes.

Hemorheological responses to an acute bout of maximal exercise in Veterans with Gulf War Illness

BackgroundAltered red blood cell (RBC) deformability has been reported in Veterans with Gulf War Illness (GWI) who endorse exercise-induced symptom exacerbation and fatigue. However, it is unknown whether altered RBC deformability is worsened secondary to exercise. ObjectiveTo evaluate RBC deformability in response to maximal exercise in individuals with and without GWI. MethodsSeventeen Veterans with GWI and 11 controls performed maximal exercise and provided blood samples (pre-, immediately post- and 60-min post-exercise). We calculated RBC deformation at infinite stress (EIMAX), shear stress for half-deformation (SS1/2) and their ratio (SS1/2/EIMAX) via repeated measures ANOVA with group and time as factors. ResultsA moderate interaction effect (p = 0.08, η2p = 0.10), large main effect for group (p = 0.02, η2p = 0.19) and moderate main effect for time (p = 0.20, η2p = 0.06) were observed for EIMAX, but only the main effect for group reached statistical significance. Changes in SS1/2 and SS1/2/EIMAX over time were similar between cases and controls as were main effects. ConclusionsVeterans with GWI had more deformable RBCs in comparison to controls that was unaffected by maximal exercise. Future studies to confirm our findings and identify associated mechanisms are warranted.

Epigenetic inheritance of DNA methylation changes in fish living in hydrogen sulfide–rich springs

Environmental factors can promote phenotypic variation through alterations in the epigenome and facilitate adaptation of an organism to the environment. Although hydrogen sulfide is toxic to most organisms, the fish Poecilia mexicana has adapted to survive in environments with high levels that exceed toxicity thresholds by orders of magnitude. Epigenetic changes in response to this environmental stressor were examined by assessing DNA methylation alterations in red blood cells, which are nucleated in fish. Males and females were sampled from sulfidic and nonsulfidic natural environments; individuals were also propagated for two generations in a nonsulfidic laboratory environment. We compared epimutations between the sexes as well as field and laboratory populations. For both the wild-caught (F0) and the laboratory-reared (F2) fish, comparing the sulfidic and nonsulfidic populations revealed evidence for significant differential DNA methylation regions (DMRs). More importantly, there was over 80% overlap in DMRs across generations, suggesting that the DMRs have stable generational inheritance in the absence of the sulfidic environment. This is an example of epigenetic generational stability after the removal of an environmental stressor. The DMR-associated genes were related to sulfur toxicity and metabolic processes. These findings suggest that adaptation of P. mexicana to sulfidic environments in southern Mexico may, in part, be promoted through epigenetic DNA methylation alterations that become stable and are inherited by subsequent generations independent of the environment.

Spectroscopic Signature of Red Blood Cells in a D-Galactose-Induced Accelerated Aging Model.

This work presents a semi-quantitative spectroscopic approach, including FTIR–ATR and Raman spectroscopies, for the biochemical analysis of red blood cells (RBCs) supported by the biochemical, morphological and rheological reference techniques. This multi-modal approach provided the description of the RBC alterations at the molecular level in a model of accelerated aging induced by administration of D-galactose (D-gal), in comparison to natural aging. Such an approach allowed to conclude that most age-related biochemical RBC membrane changes (a decrease in lipid unsaturation and the level of phospholipids, or an increase in acyl chain shortening) as well as alterations in the morphological parameters and RBC deformability are well reflected in the D-gal model of accelerated aging. Similarly, as in natural aging, a decrease in LDL level in blood plasma and no changes in the fraction of glucose, creatinine, total cholesterol, HDL, iron, or triglycerides were observed during the course of accelerated aging. Contrary to natural aging, the D-gal model led to an increase in cholesterol esters and the fraction of total esterified lipids in RBC membranes, and evoked significant changes in the secondary structure of the membrane proteins. Moreover, a significant decrease in the phosphorous level of blood plasma was specific for the D-gal model. On the other hand, natural aging induced stronger changes in the secondary structures of the proteins of the RBCs’ interior. This work proves that research on the aging mechanism, especially in circulation-related diseases, should employ the D-gal model with caution. Nonetheless, the D-gal model enables to imitate age-related rheological alterations in RBCs, although they are partially derived from different changes observed in the RBC membrane at the molecular level.

Rapid clearance of storage-induced microerythrocytes alters transfusion recovery

AbstractPermanent availability of red blood cells (RBCs) for transfusion depends on refrigerated storage, during which morphologically altered RBCs accumulate. Among these, a subpopulation of small RBCs, comprising type III echinocytes, spheroechinocytes, and spherocytes and defined as storage-induced microerythrocytes (SMEs), could be rapidly cleared from circulation posttransfusion. We quantified the proportion of SMEs in RBC concentrates from healthy human volunteers and assessed correlation with transfusion recovery, investigated the fate of SMEs upon perfusion through human spleen ex vivo, and explored where and how SMEs are cleared in a mouse model of blood storage and transfusion. In healthy human volunteers, high proportion of SMEs in long-stored RBC concentrates correlated with poor transfusion recovery. When perfused through human spleen, 15% and 61% of long-stored RBCs and SMEs were cleared in 70 minutes, respectively. High initial proportion of SMEs also correlated with high retention of RBCs by perfused human spleen. In the mouse model, SMEs accumulated during storage. Transfusion of long-stored RBCs resulted in reduced posttransfusion recovery, mostly due to SME clearance. After transfusion in mice, long-stored RBCs accumulated predominantly in spleen and were ingested mainly by splenic and hepatic macrophages. In macrophage-depleted mice, splenic accumulation and SME clearance were delayed, and transfusion recovery was improved. In healthy hosts, SMEs were cleared predominantly by macrophages in spleen and liver. When this well-demarcated subpopulation of altered RBCs was abundant in RBC concentrates, transfusion recovery was diminished. SME quantification has the potential to improve blood product quality assessment. This trial was registered at www.clinicaltrials.gov as #NCT02889133.

Impaired Cytoskeletal and Membrane Biophysical Properties of Acanthocytes in Hypobetalipoproteinemia - A Case Study.

Familial hypobetalipoproteinemia is a metabolic disorder mainly caused by mutations in the apolipoprotein B gene. In its homozygous form it can lead without treatment to severe ophthalmological and neurological manifestations. In contrast, the heterozygous form is generally asymptomatic but associated with a low risk of cardiovascular disease. Acanthocytes or thorny red blood cells (RBCs) are described for both forms of the disease. However, those morphological changes are poorly characterized and their potential consequences for RBC functionality are not understood. Thus, in the present study, we asked whether, to what extent and how acanthocytes from a patient with heterozygous familial hypobetalipoproteinemia could exhibit altered RBC functionality. Acanthocytes represented 50% of the total RBC population and contained mitoTracker-positive surface patches, indicating the presence of mitochondrial fragments. While RBC osmotic fragility, calcium content and ATP homeostasis were preserved, a slight decrease of RBC deformability combined with an increase of intracellular free reactive oxygen species were observed. The spectrin cytoskeleton was altered, showing a lower density and an enrichment in patches. At the membrane level, no obvious modification of the RBC membrane fatty acids nor of the cholesterol content were detected but the ceramide species were all increased. Membrane stiffness and curvature were also increased whereas transversal asymmetry was preserved. In contrast, lateral asymmetry was highly impaired showing: (i) increased abundance and decreased functionality of sphingomyelin-enriched domains; (ii) cholesterol enrichment in spicules; and (iii) ceramide enrichment in patches. We propose that oxidative stress induces cytoskeletal alterations, leading to increased membrane stiffness and curvature and impaired lipid lateral distribution in domains and spicules. In addition, ceramide- and spectrin-enriched patches could result from a RBC maturation defect. Altogether, the data indicate that acanthocytes are associated with cytoskeletal and membrane lipid lateral asymmetry alterations, while deformability is only mildly impaired. In addition, familial hypobetalipoproteinemia might also affect RBC precursors leading to disturbed RBC maturation. This study paves the way for the potential use of membrane biophysics and lipid vital imaging as new methods for diagnosis of RBC disorders.

New insights into the analysis of red blood cells from leukemia and anemia patients: Nonlinear quantifiers, fractal mathematics, and Wavelet Transform

The alterations of red blood cells (RBCs) membrane in many hematological diseases prevent blood to accomplish its functions, but how these alterations occur is not completely understood. Hence, the development of a simple and accurate methodology for the characterization of different populations of RBCs is necessary for hematology and clinical diagnosis. In this work, we focus on different pathologies that affect the hemorheological properties of human beings blood. The results were obtained by studying healthy individuals, anemia and leukemia patient samples. Data analysis involved the use of non-linear methods, based on two different analytical strategies. On one hand, we used nonlinear mathematical quantifiers (False Nearest Neighbors, Embedding Dimension, May–Sugihara Correlation, and Hurst Exponent) on ektacytometrically recorded time series measuring the elongation of re-suspended RBCs subjected to well-defined shear stress. On the other hand, we developed an analytical methodology to aid in the diagnosis of those pathologies, based on the box-counting dimension from digital images of cells suspensions that were denoised standardly by application of Wavelet Transform. The results allowed preliminary discrimination of different populations studied and a correlation with its membrane damage.

Increased Adhesiveness of Red Blood Cells from Sickle Cell Trait Carriers after Exposure to Daunirubicin Breast Cancer Chemotherapeutic Agent

Introduction: African-Americans (AA) with breast cancer continue to experience worse morbidity and mortality than white patients. In addition to barriers to care, an active area of investigation has been the etiology of the increased risk adverse events (AEs) related to chemotherapy. An emerging question is if sickle cell trait (i.e., heterozygotes for hemoglobin beta gene), present in an estimated 1 in 12 of the AA population, confers increased susceptibility to chemotherapy-related complications. We posit that conditions of high physiological stress might be manifest during systemic treatment with toxic agents resulting in alterations of red blood cells (RBCs). Using an experimental biomechanical model system, we hypothesized that RBCs from SCT carriers would be prone to increased adhesiveness after exposure to a common systemic anti-cancer agent used in breast cancer. Increased adhesiveness of RBCs can be a precipitating factor of blocked vasculature and subsequent sickling crises, potentially leading to AEs during treatment. Methods: Our study testedex vivoRBCs from two groups of healthy female participants: 20 African-American sickle cell trait carriers (AA-SCT); and 15 white subjects with wild-type hemoglobin (W-WT). Isolated RBCs were treated with scaled Daunorubicin (DNR) doses. The unbinding forces between αvβ3 ligands and intercellular adhesion molecule-4 (ICAM-4) receptors are reported using the frequency distribution, which states the percentage of events whose unbinding forces are within each width of the bin. We then compared the median values of the forces measured in experiments without and with treatment for each drug. The collective frequency (CF%) is related to the population of active ICAM-4 receptors and is defined as the percentage of all unbinding events divided by the total number of measurements, which is 32 × 32 =1024 for each cell multiplied by the number of tested cells for each blood sample. Results: For AA-SCT RBCs, pre-treatment baseline CF of active ICAM-4 receptors was 4.88 ± 0.87%, which was significantly increased after administration of DNR (13.13 ± 2.30%, p&amp;lt;0.0001). In contrast, treatment of W-WT RBCs held the CF of active ICAM-4 receptors at a comparable level as untreated RBCs (9.54 ± 1.48%; 7.47 ± 1.07%, p=0.50, respectively). Conclusion: Our findings could support hypotheses for adhesion-related RBC clumping among AAs with SCT during systemic treatment with anti-neoplastic agents, and, putatively, resultant AEs. Given past studies showing African-American women with breast cancer have higher rates of self-withdrawal from treatment, further exploration with additional systemic agents are warranted. Our novel study is limited by a small sample size as well lack of potential confounding factors in analyses. Future studies are planned with additional agent(s) and AAs without SCT. Should it be confirmed that SCT carrier status predicts RBC alterations during systemic treatment for breast cancer, and are linked to subsequent adverse events, it could lead to precision treatment planning. Disclosures Andemariam: Novartis:Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Hemanext:Membership on an entity's Board of Directors or advisory committees;Global Blood Therapeutics:Consultancy, Membership on an entity's Board of Directors or advisory committees;Vertex:Honoraria;Imara:Research Funding;Emmaus:Membership on an entity's Board of Directors or advisory committees;bluebird bio:Consultancy, Membership on an entity's Board of Directors or advisory committees;NovoNordisk:Consultancy, Membership on an entity's Board of Directors or advisory committees;CRISPR/Vertex:Consultancy, Membership on an entity's Board of Directors or advisory committees;CHNCT:Consultancy;Accordant:Membership on an entity's Board of Directors or advisory committees;Guidepoint:Honoraria;Sanofi Genzyme:Consultancy, Membership on an entity's Board of Directors or advisory committees;Terumo BCT:Consultancy, Membership on an entity's Board of Directors or advisory committees;Roche:Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees;Cyclerion:Consultancy, Membership on an entity's Board of Directors or advisory committees;Pfizer:Consultancy, Membership on an entity's Board of Directors or advisory committees.

Hematological and Oxidative Status Parameters in Domestic Dogs Naturally Infested by Rhipicephalus Sp.

Abstract The present study was aimed to evaluate hematological and oxidative stress parameters in domestic dogs infested naturally (n=10) by Rhipicephalus sp. to compare with non-infested dogs (n=10). All blood samples were collected from brachial vein into tubes EDTA for the hematological analysis such as red blood cells (RBCs), white blood cells (WBCs), hemoglobin (HGB) and platelets (PLT). Serum was rapidly separated after centrifugation and stored at -20 °C until it was used for malondialdehyde (MDA) and 2,2’-Azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) inhibition measurements. HGB in non-infested dogs was significantly higher than in infested dogs (P&lt;0.05). There was no significant difference in RBCs, WBCs and PLT between both groups (P&gt;0.05). The mean of MDA concentration was high in infested dogs (0.92±0.62 nmol/ml) compared to non-infested dogs (0.75±0.25 nmol/ml). On the other hand, the percentage of ABTS inhibition was similar in both groups (P=0.71). High tick number seems significantly affected WBCs (P&lt;0.0001) and HGB (P&lt;0.001) in infested dogs. Concerning oxidative status, there was no significant differences (P&gt;0.05) between low and high infested dogs, neither in the amount of MDA nor in the ABTS inhibition. In conclusion, infested dogs induced RBCs alterations, which coincided with the oxidative damage, as evidenced by MDA serum levels. Also, there was a relationship between the tick number in infested dogs and the hematological parameters.

Age–related and atherosclerosis–related erythropathy in ApoE/LDLR−/− mice

In this work we applied a multimodal approach to define the age– and atherosclerosis–related biochemical and functional alterations in red blood cells (RBCs) in ApoE/LDLR−/− mice. Our results revealed that age–related changes in RBCs, such as decreases in RBC deformability and mean height, were more pronounced in ApoE/LDLR−/− mice than in age–matched control mice (C57BL/6J). The decreases in phospholipid content and level of lipid unsaturation were accompanied by an increase in cholesterol esters and esterified lipids in RBC membranes in aged C57BL/6J mice. The age–related decrease in the phospholipid content was more pronounced in ApoE/LDLR−/− mice. In contrast, the increase in the total lipid content in RBC membranes occurred only in ApoE/LDLR−/− mice with advanced atherosclerosis. The age–related alterations also included a decrease in the ratio of turns to α–helices in the secondary structure of hemoglobin (Hb) inside intact RBCs. On the other hand, an increase in the ratio of unordered conformations to α–helices of Hb was observed only in ApoE/LDLR−/− mice and occurred already at the age of 5–weeks. This was related to hypercholesterolemia and resulted in an increased oxygen-carrying capacity. In conclusion, progressive mechanical and functional alterations of RBCs in aged ApoE/LDLR−/− mice were more pronounced than in age–matched C57BL/6J mice. Although, several biochemical changes in RBCs in aged ApoE/LDLR−/− mice recapitulated age–dependent changes observed in control mice, some biochemical features of RBC membranes attributed to hypercholesterolemia were distinct and could contribute to the accelerated deterioration of RBC function in ApoE/LDLR−/− mice.

Hypercholesterolemia associated with erythrocytes morphology assessed by scanning electron microscopy in metabolically unhealthy individuals with normal-weight and obesity

AimsTo associate hypercholesterolemia and obesity with red blood cell (RBC) morphology as assessed by scanning electron microscopy (SEM) in metabolically healthy and unhealthy adults with normal weight and with obesity. MethodsCross-sectional study with four groups: metabolically healthy with normal-weight (MHNW, n = 12), metabolically unhealthy with normal-weight (MUNW, n = 5), metabolically healthy with obesity (MHO, n = 4), and metabolically unhealthy with obesity (MUO, n = 6). SEM was used to assess the RBC morphology (diameter, height, and axial ratio, n = 810 cells). SEM images were analyzed using Gwyddion software to measure the RBC morphology parameters. ResultsSEM images showed altered RBC morphologies in the MUNW, MHO, and MUO groups. Diameter and axial ratio were statistically different after comparison of MHNW vs. MUNW (+0.41 μm, +0.05 μm); MUNW vs. MHO (−0.70 μm, −0.05 μm); and MHO vs. MUO (+0.38 μm, +0.04 μm), respectively. Hypercholesterolemia was associated with larger and more elongated RBC, while obesity with smaller RBC. Besides, age, HDL, ultra-processed food consumption were associated with altered RBC morphology. ConclusionsSEM is an excellent instrument to assess qualitatively and quantitatively RBC morphology. Hypercholesterolemia and obesity had a negative effect on the RBC morphology, but producing different effects on the RBC morphology (larger and smaller RBC, respectively).

Administration of glycerol-based formulations in sheep results in similar ovulation rate to eCG but red blood cell indices may be affected

BackgroundThe objective of this study was to investigate the metabolic and osmotic effects of different doses of glycerol or a glycerol – propylene glycol mixture in Sarda sheep with the aim to identify those able to beneficially modify ewe’s metabolic status without harmful changes in red blood cell (RBC) indices. Thereafter, the selected doses were tested for their effects on ewe’s ovarian activity during an induced follicular phase and compared to the effects of a hormonal treatment with equine chorionic gonadotrophin (eCG).ResultsGlycerol was administered alone (G groups: 90% glycerol and 10% water; % v/v) or in combination with propylene glycol (M groups: 70% glycerol, 20% propylene glycol, 10% water; % v/v). Treatments were formulated to provide 100, 75, 50 and 25% of the amount of energy supplied in previous experiments. Obtained results showed that the formulations G75 and M75 (22.5 and 18.2% on DM basis, respectively) induce metabolic changes comparable to those induced by M100. The latter dose has been already evaluated for its effects on sheep metabolism and reproductive performance. However, with these high doses, plasma osmolality increased significantly, and RBC indices showed significant alterations. The low dose groups (G25 and M25, 8.6 and 6.9% on DM basis, respectively) did not show any alterations in plasma osmolality and RBC indices, but the metabolic milieu differed markedly from that of M100. Between the medium dose groups, M50 (12.9% on DM basis) showed a more comparable milieu to M100 than G50 (15.9% on DM basis) and no RBC alterations. Therefore, M75, G75 and M50 doses were tested for their effect on ovarian functions and proved to be equally effective as eCG.ConclusionThe results of the present study evidenced an alteration of RBC indices, and possibly of their functions, as a side effect of glycerol administration at high doses in the diet of ewes. Therefore, protocols foreseeing the administration of glycerol should be tested for their effects on RBC indices and functions. In general terms, the medium dose of the glucogenic mixture (12.9% of dietary DM on offer) should be preferred.