Search

• Plasma docosahexaenoic acid (DHA) was inversely associated with prediabetes risk. • Plasma DHA was inversely associated with glycated hemoglobin A1c. • Prediabetes prevalence was highest with lowest plasma DHA proportions vs highest. • Prediabetics had lower DHA and total omega-3 fatty acid proportions in plasma. • Omega-3 fatty acids, especially DHA, may protect against prediabetes. Prediabetes and type 2 diabetes mellitus are growing global health concerns, predisposing individuals to various vascular complications. Lifestyle modifications, including dietary interventions, offer promising avenues for prevention and management. Using a multivariable-adjusted model, we analyzed the cross-sectional associations between plasma proportions (% of total fatty acids) of omega-3 polyunsaturated fatty acids (n 3 PUFA, including total n 3 PUFA, docosahexaenoic acid [DHA], non-DHA n 3 PUFA), and glycated hemoglobin A1c (HbA1c) as well as the prevalence of prediabetes in a sample from the UK Biobank cohort. Our hypothesis was that proportions of n 3 PUFA, especially DHA, would by inversely associated with the prediabetes prevalence. The sample (n = 92,762; 54.5% females) had an average age of 56 years and was overweight (mean body mass index = 27). The mean plasma DHA proportion in the sample was 2.03% (standard deviation [SD] = 0.67%), non-DHA n 3 PUFA was 2.41% (SD = 1.02%) and total n 3 PUFA was 4.43% (SD = 1.56%). Prediabetic individuals were identified by blood HbA1c proportions between 5.7% and 6.4% (39-46 mmol/mol) according to American Diabetes Association criteria. Each of the three n 3 PUFA biomarkers was inversely associated with HbA1c proportions. In particular, DHA showed the strongest inverse association, with an OR of 0.62 (95% confidence intervals: 0.58, 0.67; P <.001) when comparing quintiles 5 to 1 in a fully adjusted model. These findings suggest a potential protective role of n 3 PUFA, particularly DHA, in mitigating the risk of having prediabetes. Further prospective investigations are needed to clarify whether long-chain n 3 PUFA could function as modifiable factors for prediabetes. A cross-sectional analysis of the UK Biobank cohort found that lower plasma proportions of n 3 PUFA, especially DHA, were associated with a prevalence and odds of prediabetes. The prevalence of prediabetes was highest in individuals with the lowest DHA proportions (17.4%) compared to those with the highest (10.6%), suggesting a protective role of DHA against prediabetes. Abbreviations: DHA, docosahexaenoic acid; n 3 PUFA, omega-3 polyunsaturated fatty acids. [Display omitted] [ABSTRACT FROM AUTHOR]

Ex vivo production of red blood cells (RBCs) represents a promising alternative for transfusion medicine. Several strategies have been described to generate erythroid cell lines from different sources, including embryonic, induced pluripotent, and hematopoietic stem cells. All these approaches have in common that they require elaborate differentiation cultures whereas the yield of enucleated RBCs is inefficient. We generated a human immortalized adult erythroid progenitor cell line derived from bone marrow CD71-positive erythroid progenitor cells (immortalized bone marrow erythroid progenitor adult, or imBMEP-A) by an inducible expression system, to shorten differentiation culture necessary for terminal erythroid differentiation. It is the first erythroid cell line that is generated from direct reticulocyte progenitors and demonstrates robust hemoglobin production in the immortalized state. Morphologic analysis of the immortalized cells showed that the preferred cell type of the imBMEP-A line corresponds to hemoglobin-producing basophilic erythroblasts. In addition, we were able to generate a stable cell line from a single cell clone with the triple knockout of RhAG, RhDCE and KELL. After removal of doxycycline, part of the cells differentiated into normoblasts and reticulocytes within 5–7 days. Our results demonstrate that the imBMEP-A cell line can serve as a stable and straightforward modifiable platform for RBC engineering in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

One of the physical methods for obtaining magnetite nanoparticles (NPs) is electron beam physical vapor deposition (EB PVD), which requires complex equipment, but allows obtaining a significant amount of pure (ligand-free) NPs. The biomedical application of such NPs is less studied than materials from other synthesis methods. The objective is to study the effect of pure magnetite NPs in the NaCl matrix obtained by EB PVD on hematological indicators, gases, electrolytes and parameters of iron metabolism in the blood of intact animals. The physical characteristics of NPs were studied using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, electron energy-loss spectroscopy, selected area electron diffraction and fast Fourier transform. In vivo experiments were conducted on albino male rats, which were injected with solution of magnetite-sodium chloride NPs (1.35 mg Fe/kg). After 3 and 72 h, hematological parameters, blood gases, electrolytes, and serum iron were determined. The synthesized NPs had an average size of 11 nm. They were identified as magnetite, where polycrystals and single crystals were present. The absence of contamination in crystal boundaries, clear orientation and orderliness of atoms in crystals were established. The administration of NPs in the sodium chloride matrix to animals was characterized by a transient increase in the main indicators of red blood accompanied by an increase in the saturation of erythrocytes with hemoglobin and their mean volume after 3 h. It did not worsen blood gases and pH, but decreased blood Na+ content after 72 h. The investigated NPs caused changes in the parameters of serum iron characteristic to iron preparations, which after 3 h were smaller compared to the reference iron drug, and after 72 h—similar to it. More intense rapid effects on hematological parameters at lower serum iron indicate greater activity of the studied pure magnetite NPs obtained by EB PVD syntesis compared to the reference iron preparation. Highlights: Pure magnetite nanoparticles in the NaCl matrix were obtained by EB PVD. They were studied using high-resolution transmission electron microscopy. These nanoparticles had a size of 11 nm, clear orientation and orderliness of atoms in crystals. In healthy animals, they caused a transient increase in red blood indicators. They did not worsen blood gases and pH, but decreased Na+ content in the blood. The nanoparticles caused changes in the serum iron typical to iron preparations. These changes were not toxic and lasting due to compensatory reactions. [ABSTRACT FROM AUTHOR]

Aim: To identify the physiological role of the acid‐base sensing enzyme, soluble adenylyl cyclase (sAC), in red blood cells (RBC) of the model teleost fish, rainbow trout. Methods: We used: (i) super‐resolution microscopy to determine the subcellular location of sAC protein; (ii) live‐cell imaging of RBC intracellular pH (pHi) with specific sAC inhibition (KH7 or LRE1) to determine its role in cellular acid‐base regulation; (iii) spectrophotometric measurements of haemoglobin–oxygen (Hb‐O2) binding in steady‐state conditions; and (iv) during simulated arterial‐venous transit, to determine the role of sAC in systemic O2 transport. Results: Distinct pools of sAC protein were detected in the RBC cytoplasm, at the plasma membrane and within the nucleus. Inhibition of sAC decreased the setpoint for RBC pHi regulation by ~0.25 pH units compared to controls, and slowed the rates of RBC pHi recovery after an acid‐base disturbance. RBC pHi recovery was entirely through the anion exchanger (AE) that was in part regulated by HCO3−‐dependent sAC signaling. Inhibition of sAC decreased Hb‐O2 affinity during a respiratory acidosis compared to controls and reduced the cooperativity of O2 binding. During in vitro simulations of arterial‐venous transit, sAC inhibition decreased the amount of O2 that is unloaded by ~11%. Conclusion: sAC represents a novel acid‐base sensor in the RBCs of rainbow trout, where it participates in the modulation of RBC pHi and blood O2 transport though the regulation of AE activity. If substantiated in other species, these findings may have broad implications for our understanding of cardiovascular physiology in vertebrates. [ABSTRACT FROM AUTHOR]

With the declining birth rates and aging societies in developed countries, the average age of the working population is increasing. Older people tend to get tired more easily, so prevention of fatigue is important to improve the quality of life for older workers. This study aimed to assess the mechanism of fatigue in older people, especially focused on relation between dysfunction of erythrocyte and fatigue. Total power (TP), which is the value of autonomic nerve activity, was measured as a value of fatigue and significantly decreased in workers with aging. As properties of senescent erythrocytes, the erythrocyte sedimentation rate and damaged erythrocytes population increased with aging and correlated with TP. These results suggested that the accumulation of damaged erythrocytes contributes to fatigue. Recent studies revealed that senescence-associated secretory phenotype (SASP), a phenomenon in which senescent cells secrete a variety of cytokines, affected hematopoiesis in bone marrow. We analyzed the effects of SASP factors on erythropoiesis and found that Interleukin -1α (IL-1α) suppressed erythrocyte differentiation of hematopoietic stem cells in vitro. We also showed that IL-1α levels in human blood and saliva increase with aging, suggesting the possibility that IL-1α level in saliva can be used to predict the decline in hematopoietic function. [ABSTRACT FROM AUTHOR]

Erythrophagocytosis is a process consisting of recognition, engulfment and digestion by phagocytes of antibody‐coated or damaged erythrocytes. Understanding the dynamics that are behind erythrophagocytosis is fundamental to comprehend this cellular process under specific circumstances. Several techniques have been used to study phagocytosis. Among these, an interesting approach is the use of Imaging Flow Cytometry (IFC) to distinguish internalization and binding of cells or particles. However, this method requires laborious analysis. Here, we introduce a novel approach to analyze the phagocytosis process by combining Artificial Intelligence (AI) with IFC. Our study demonstrates that this approach is highly suitable to study erythrophagocytosis, categorizing internalized, bound and non‐bound erythrocytes. Validation experiments showed that our pipeline performs with high accuracy and reproducibility. [ABSTRACT FROM AUTHOR]

Simple Summary: Asinara donkeys are unique worldwide for expressing a particular form of albinism spread to all individuals of the breed. This peculiar condition of oculo-cutaneous albinism of type 1 (OCA1) is a rare condition from a recessive autosomic mutation, fixed through generations, thanks to the isolation of donkeys on Asinara Island (from which the breed name originates) favoring inbreeding. Asinara island is a small island of Sardinia, one of the biggest islands in the Mediterranean sea. Asinara donkeys have shown good adaptation to the Mediterranean climate through various metabolic strategies, one of which relies on endogenous retinol mobilization during the positive photoperiod for protective effect and adequate circulating vitamin E. Indeed, their exposure to sun radiation and high temperature on one hand, and the lack of melanin in the coat, skin, iris and mucocutaneous junctions on the other, require them to overcome such an extended lack of photoprotective pigment (melanin) in alternative ways to prevent UV radiation damage. In this investigation, our interest was oriented toward screening the complete blood cell count to understand whether metabolic adaptation to the environment involved blood cell lines. Such an idea comes from the fact that in humans, a particular condition of albinism is reported to share the same gene with other mutations involving hemoglobin synthesis. In our case, significant differences were observed in relation to red blood cells (RBCs), in terms of their average volume (MCV), width distribution (RDW-CV), and width deviation (RDW-SD), in comparison to pigmented (gray) Sardo donkeys. The complete blood cell count (CBC) was screened in a group of 15 donkeys, of which 8 were of Asinara breed (oculocutaneous albinism type 1, OCA1) and 7 of Sardo breed (gray coat). All donkeys were kept under same management and dietary conditions and underwent periodic health monitoring in the month of June 2024, at the peak of the positive photoperiod, at Mediterranean latitudes. One aliquot of whole blood, drawn from each individual into K2-EDTA containing tubes, was analyzed for the complete blood cell count through an automatic analyzer, within two hours of sampling. Data were analyzed and compared by one-way ANOVA, where the breed was an independent variable. All animals appeared clinically healthy, though mild eosinophilia was observed in Sardo donkeys. The red blood cell line showed peculiar traits for Asinara donkeys, which displayed significantly higher circulating red blood cell numbers than gray coat Sardo donkeys (RBC, 5.19 vs. 3.80 1012/mL ± 0.98 pooled-St. Dev, respectively; p = 0.017). RBCs also exhibited a smaller diameter and higher degree of anisocytosis in Asinara donkeys, along with lower hematocrit value, albeit within physiological ranges. Taken all together, such hematological profile depicts a peculiar trait of the red blood cell line in albino donkeys during the positive photoperiod. [ABSTRACT FROM AUTHOR]

There is a growing interest in using extracellular vesicles (EVs) for therapeutic applications. EVs are composed of cytoplasmic proteins and nucleic acids and an external lipid bilayer containing transmembrane proteins on their surfaces. EVs can alter the state of the target cells by interacting with the receptor ligand of the target cell or by being internalised by the target cell. Blood cells are the primary source of EVs, and 1 μL of plasma contains approximately 1.5 × 107 EVs. Owing to their easy acquisition and the avoidance of cell amplification in vitro , using blood cells as a source of therapeutic EVs has promising clinical application prospects. This review summarises the characteristics and biological functions of EVs derived from different blood cell types (platelets, erythrocytes, and leukocytes) and analyses the prospects and challenges of using them for clinical therapeutic applications. In summary, blood cell-derived EVs can regulate different cell types such as immune cells (macrophages, T cells, and dendritic cells), stem cells, and somatic cells, and play a role in intercellular communication, immune regulation, and cell proliferation. Overall, blood cell-derived EVs have the potential for use in vascular diseases, inflammatory diseases, degenerative diseases, and injuries. To promote the clinical translation of blood cell-derived EVs, researchers need to perform further studies on EVs in terms of scalable and reproducible isolation technology, quality control, safety, stability and storage, regulatory issues, cost-effectiveness, and long-term efficacy. [Display omitted] • Blood contains EVs derived from platelets, erythrocytes, and leukocytes. • Blood cell-derived EVs regulate intercellular communication and immune responses. • Blood cell-derived EVs have therapeutic potential in various diseases. [ABSTRACT FROM AUTHOR]

Abstract One of the physical methods for obtaining magnetite nanoparticles (NPs) is electron beam physical vapor deposition (EB PVD), which requires complex equipment, but allows obtaining a significant amount of pure (ligand-free) NPs. The biomedical application of such NPs is less studied than materials from other synthesis methods. The objective is to study the effect of pure magnetite NPs in the NaCl matrix obtained by EB PVD on hematological indicators, gases, electrolytes and parameters of iron metabolism in the blood of intact animals. The physical characteristics of NPs were studied using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, electron energy-loss spectroscopy, selected area electron diffraction and fast Fourier transform. In vivo experiments were conducted on albino male rats, which were injected with solution of magnetite-sodium chloride NPs (1.35 mg Fe/kg). After 3 and 72 h, hematological parameters, blood gases, electrolytes, and serum iron were determined. The synthesized NPs had an average size of 11 nm. They were identified as magnetite, where polycrystals and single crystals were present. The absence of contamination in crystal boundaries, clear orientation and orderliness of atoms in crystals were established. The administration of NPs in the sodium chloride matrix to animals was characterized by a transient increase in the main indicators of red blood accompanied by an increase in the saturation of erythrocytes with hemoglobin and their mean volume after 3 h. It did not worsen blood gases and pH, but decreased blood Na+ content after 72 h. The investigated NPs caused changes in the parameters of serum iron characteristic to iron preparations, which after 3 h were smaller compared to the reference iron drug, and after 72 h—similar to it. More intense rapid effects on hematological parameters at lower serum iron indicate greater activity of the studied pure magnetite NPs obtained by EB PVD syntesis compared to the reference iron preparation.

Qian Meng,1,&ast; Xiaowei Yang,1,&ast; Zhongcheng Liu,2 Guoxing You,3 Wanyi Chen,3 Bing Zhao,1 Huizi Zhu,4 Liang Xu,1 Yan Zhou,1 Xiang Liu,1 Chunjuan Zhai,5 Rong Wang,1 Lian Zhao,3 Jing Sun1 1Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, 250021, People’s Republic of China; 2Department of Cardiovascular, The North City Hospital of Jinan, Jinan, Shandong, 250031, People’s Republic of China; 3Academy of Military Medical Sciences, Beijing, 100850, People’s Republic of China; 4Department of Nephrology, Fuyang People’s Hospital, Fuyang, Anhui, 236000, People’s Republic of China; 5Department of Cardiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, 250021, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jing Sun, Department of Nephrology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, 324 Jingwu Road, Jinan, Shandong, 250021, People’s Republic of China, Tel +86 151 6888 6367, Email sunj5708@126.com Lian Zhao, Academy of Military Medical Sciences, 27 Taiping Road, Beijing, 100850, People’s Republic of China, Tel +8613671217095, Email zhaolian@bmi.ac.cnPurpose: Chronic kidney disease (CKD) is associated with persistent systemic inflammation. Reduced red blood cell (RBC) survival in patients with CKD has been identified for several decades. The purpose of this study is to explore whether excessive erythrophagocytosis exists and contributes to systemic inflammation in CKD.Patients and methods: A CKD rat model was induced by 5/6 nephrectomy. Erythrocyte osmotic fragility was determined with hypotonic NaCl solutions. Erythrocyte deformability was evaluated by filterability. RBC cell death was quantified using fluorescence-activated cell sorting analyses of fluorescent annexin V–bound surface phosphatidylserine (PS). Erythrophagocytosis was evaluated in vivo and in vitro. RT-qPCR and immunohistochemistry were used to determine the inflammatory effects after erythrophagocytosis.Results: Erythrocyte osmotic fragility and deformability progressively declined, and the percentage of PS-exposing RBCs progressively increased in CKD rats. Levels of erythrophagocytosis in vivo were evaluated by autologous injection of CFSE-labeled erythrocytes. In comparison with the control group, higher fluorescence intensity of CFSE was detected in the spleen homogenates of rats with CKD. In vitro, more of erythrocytes from 5/6Nx rats were phagocytosed by peritoneal macrophages in comparison to those from control rats. Compared with macrophages phagocytosed control erythrocytes, macrophages phagocytosed CKD erythrocytes exhibited higher mRNA levels of IL-6, CXCL-10, CXCL-11, iNOS, IL-1β, ICAM-1 and MCP-1. Compared with the control group, the red pulp of rats with CKD exhibited higher levels of p-NFκB, IL-6, iNOS and CXCL-10. ELISA results showed significantly increased plasma levels of both IL-6 and CXCL-10 in patients with long-term hemodialysis compared with those in healthy controls (2.30 ± 1.38 pg/mL vs 1.33 ± 0.65 pg/mL, P=0.01; 78.11 ± 27.34 pg/mL vs 37.45 ± 7.08 pg/mL, P=0.001).Conclusion: Our results indicated that excessive erythrophagocytosis may contribute to systemic inflammation in CKD. Keywords: chronic kidney disease, chronic inflammation, erythrocyte, phagocytosis

Microparticles have demonstrated value for regenerative medicine. Attempts in this field tend to focus on the development of intelligent multifunctional microparticles for tissue regeneration. Here, inspired by erythrocytes-associated self-repairing process in damaged tissue, we present novel biomimetic erythrocyte-like microparticles (ELMPs). These ELMPs, which are composed of extracellular matrix-like hybrid hydrogels and the functional additives of black phosphorus, hemoglobin, and growth factors (GFs), are generated by using a microfluidic electrospray. As the resultant ELMPs have the capacity for oxygen delivery and near-infrared-responsive release of both GFs and oxygen, they would have excellent biocompatibility and multifunctional performance when serving as microscaffolds for cell adhesion, stimulating angiogenesis, and adjusting the release profile of cargoes. Based on these features, we demonstrate that the ELMPs can stably overlap to fill a wound and realize controllable cargo release to achieve the desired curative effect of tissue regeneration. Thus, we consider our biomimetic ELMPs with discoid morphology and cargo-delivery capacity to be ideal for tissue engineering.

Necroptosis is considered a programmed necrosis that requires receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and pore-forming mixed lineage kinase domain-like protein (MLKL) to trigger a regulated cell membrane lysis. Membrane rupture in necroptosis has been shown to fuel innate immune response due to release of damage-associated molecular patterns (DAMPs). Recently published studies indicate that mature erythrocytes can undergo necroptosis as well. In this review, we provide an outline of multiple cell death modes occurring in erythrocytes, discuss possible immunological aspects of diverse erythrocyte cell deaths, summarize available evidence related to the ability of erythrocytes to undergo necroptosis, outline key involved molecular mechanisms, and discuss the potential implication of erythrocyte necroptosis in the physiology and pathophysiology. Furthermore, we aim to highlight the interplay between necroptosis and eryptosis signaling in erythrocytes, emphasizing specific characteristics of these pathways distinct from their counterparts in nucleated cells. Thus, our review provides a comprehensive summary of the current knowledge of necroptosis in erythrocytes. To reflect critical differences between necroptosis of nucleated cells and necroptosis of erythrocytes, we suggest a term erythronecroptosis for necroptosis of enucleated cells. [ABSTRACT FROM AUTHOR]

Abstract Aims Low‐density lipoprotein cholesterol (LDL‐C), anaemia and low platelets have been associated with worse clinical outcomes in heart failure patients. We investigated the relationship between the combination of these three components and clinical outcome in patients with heart failure with preserved ejection fraction (HFpEF). Methods and results We examined the data of 1021 patients with HFpEF hospitalized with acute decompensated heart failure (HF) from the PURSUIT‐HFpEF registry, a prospective, multicenter observational study. The enrolled patients were classified into four groups by an LEP (LDL‐C, Erythrocyte, and Platelet) score of 0 to 3 points, with 1 point each for LDL‐C, erythrocyte and platelet values less than the cut‐off values as calculated by receiver operating characteristic curve analysis. The endpoint, a composite of all‐cause death and HF readmission, was evaluated among the four groups. Median follow‐up duration was 579 [300, 978] days. Risk of the composite endpoint significantly differed among the four groups (P

Introduction: Oligomeric alpha-synuclein in red blood cells (RBC-o-α-Syn) has been shown to be increased in patients with Parkinson's disease (PD). However, factors that affect RBC-o-α-Syn levels remain to be elucidated. The aim of this study is to analyze the correlations between RBC-o-α-Syn levels and the age, sex and different clinical variables of patients with PD. Methods: 167 patients with PD and 119 healthy controls (HC) were enrolled in this study. The patients with PD were diagnosed based on the MDS clinical diagnostic criteria for PD. All participants were evaluated for their clinical characteristics. Western blot analysis was used to examine the molecular sizes of RBC-o-α-Syn. A newly established chemiluminescent immunoassay was used to measure RBC-o-α-Syn levels. Results: Higher RBC-o-α-Syn levels were detected in PD patients than in HC subjects. The receiver operating characteristic (ROC) curve indicated that a cut off value of 55.29 ng/mg discriminated well between PD patients and HC subjects, with a sensitivity of 67.66% (95% CI: 60.24-74.29%), a specificity of 88.24% (95% CI: 81.22-92.86%), and an area under the curve (AUC) of 0.857. The levels of RBC-o-α-Syn were higher in female than male patients (p = 0.033). For different subtypes, the levels of RBC-o-α-Syn were higher in the MIX subtype than the tremor-dominant (TD) PD. In addition, the levels of RBC-o-α-Syn were higher in patients with than without cognitive impairment (p = 0.016), and negatively correlated with Mini-Mental State Examination (MMSE) scores (r = -0.156, p = 0.044). Conclusion: Our study demonstrates that RBC-o-α-Syn levels in patients with PD are higher than those in HC subjects and affected by the sex and the severity of cognitive impairment. [ABSTRACT FROM AUTHOR]

Traumatic meniscal injuries can cause acute pain, hemarthrosis (bleeding into the joint), joint immobility, and post-traumatic osteoarthritis (PTOA). However, the exact mechanism(s) by which PTOA develops following meniscal injuries is unknown. Since meniscus tears commonly coincide with hemarthrosis, investigating the direct effects of blood and its constituents on meniscus tissue is warranted. The goal of this study was to determine the direct effects of blood and blood components on meniscus tissue catabolism. Porcine meniscus explants or primary meniscus cells were exposed to whole blood or various fractions of blood for 3 days to simulate blood exposure following injury. Explants were then washed and cultured for an additional 3 days prior to collection for biochemical analyses. Whole blood increased matrix metalloproteinase (MMP) activity. Fractionation experiments revealed blood-derived red blood cells did not affect meniscus catabolism. Conversely, viable mononuclear leukocytes induced MMP activity, nitric oxide (NO) production, and loss of tissue sulfated glycosaminoglycan (sGAG) content, suggesting that these cells are mediating meniscus catabolism. These findings highlight the potential challenges of meniscus healing in the presence of hemarthrosis and the need for further research to elucidate the in vivo effects of blood and blood-derived mononuclear leukocytes due to both hemarthrosis and blood-derived therapeutics. [ABSTRACT FROM AUTHOR]

Oral intake of purified selenoneine and seafoods has been reported to result in selenoneine accumulation in erythrocytes in mice and human. In addition, Se-methylselenoneine was suggested to be produced as a metabolite of selenoneine in the urine and whole blood of humans. In order to confirm the molecular mechanism of production of Se-methylselenoneine, a stable isotope (Se-76) labeled selenoneine was biosynthesized using genetically modified fission yeast and administered to mice. The Se-76-labeled Se-methylselenoneine was detected in urine but Se-78 and Se-80-labeled Se-methylselenoneine arising from natural isotopes of Se was hardly detected. These results suggest that Se-methylselenoneine was a metabolite and the excreted form of selenoneine. The methylation of selenoneine in mice administered selenoneine continuously was evaluated by the analyses of organs using an online liquid chromatograph system with an inductively coupled plasma mass spectrometer (LC-ICP-MS). These experiments indicate that selenoneine is methylated in the liver and (or) kidneys. [ABSTRACT FROM AUTHOR]

Blood transfusion is a common therapeutic intervention in hospitalized patients. There are numerous indications for transfusion, including anemia and coagulopathy with deficiency of single or multiple coagulation components such as platelets or coagulation factors. Nevertheless, the practice of transfusion in critically ill patients has been controversial mainly due to a lack of evidence and the need to consider the appropriate clinical context for transfusion. Further, transfusion carries many risk factors that must be balanced with benefits. Therefore, transfusion practice in ICU patients has constantly evolved, and we endeavor to present a contemporary review of transfusion practices in this population guided by clinical trials and expert guidelines. [ABSTRACT FROM AUTHOR]

Low energy availability (LEA) is a growing concern that can lead to several problems for athletes. However, adaptation to LEA occurs to maintain balance over time, making diagnosis difficult. In this review, we categorize LEA into two phases: the initial phase leading to adaptation and the phase in which adaptation is achieved and maintained. We review the influence of LEA on sports performance and health and discuss biomarkers for diagnosing LEA in each phase. This review also proposes future research topics for diagnosing LEA, with an emphasis on the recently discovered association between red blood cell turnover and LEA. [ABSTRACT FROM AUTHOR]

This systematic review and meta-analysis aim to establish associations between metabolic syndrome (MetS) and erythrocyte and platelet markers, contributing to improved diagnostic tests for identifying individuals at risk. Observational studies and Randomized Controlled Trials (RCTs) were included. The standardized mean difference (SMD) and 95% confidence intervals (CI) of erythrocyte and platelet markers between individuals with and without MetS were used as effect size (inverse variance model). Methodological quality assessment was conducted using the Newcastle-Ottawa scale (NOS) for observational studies and the Cochrane Risk of Bias tool 2.0 for RCTs. The analysis included 51 articles. Compared to controls, individuals with MetS exhibited significantly higher concentrations of mean red blood cell count [Standardized Mean Difference (95% CI): 0.15 (0.13−0.18); p<0.00001], hemoglobin [0.24 (0.18−0.31); p<0.00001], blood platelet count [5.49 (2.78–8.20); p<0.0001], and red blood cell distribution width [(0.55 (0.05–1.04); p=0.03]. Regarding mean platelet volume [0.16 (– 0.03 to 0.35); p=0.10] and platelet-to-lymphocyte ratio (PLR) [7.48 (–2.85–17.81); p=0.16], a non-significant difference was observed in patients with MetS. There was no statistically significant difference in hematocrit counts between the two groups [0.47 (–0.40 to –1.34); p=0.29]. Biomarkers such as mean red blood cell count, hemoglobin, blood platelet count, and RDW are associated with higher levels in patients in MetS, whereas mean platelet volume and PLR tend to be lower. These markers can potentially provide new avenues for early diagnosis of MetS. [ABSTRACT FROM AUTHOR]

This study investigates whether exercise as a strategy for improving physical fitness at sea level also offers comparable benefits in the unique context of high altitudes (HA), considering the physiological challenges of hypoxic conditions. Overall, 121 lowlanders who had lived on the Tibetan Plateau for >2 years and were still living at HA during the measurements were randomly classified into four groups. Each individual of the low‐intensity (LI), moderate‐intensity (MI), and high‐intensity (HI) groups performed 20 sessions of aerobic exercise at HA (3680 m) over 4 weeks, while the control group (CG) did not undergo any intervention. Physiological responses before and after the intervention were observed. The LI and MI groups experienced significant improvement in cardiopulmonary fitness (0.27 and 0.35 L/min increases in peak oxygen uptake [V˙ $\dot{\mathrm{V}}$O2peak], both p < 0.05) after exercise intervention, while the hematocrit (HCT) remained unchanged (p > 0.05). However, HI exercise was less efficient for cardiopulmonary fitness of lowlanders (0.02 L/min decrease in V˙ $\dot{\mathrm{V}}$O2peak, p > 0.05), whereas both the HCT (1.74 %, p < 0.001) and glomerular filtration rate (18.41 mL/min, p < 0.001) increased with HI intervention. Therefore, LI and MI aerobic exercise, rather than HI, can help lowlanders in Tibet become more acclimated to the HA by increasing cardiopulmonary function and counteracting erythrocytosis. Highlights: Low‐ and moderate‐intensity exercise at HA can improve oxygen transport of lowlanders that may help them to become more acclimated to high altitude.High‐intensity exercise performed by lowlanders may result in erythrocytosis without improving oxygen transport.The relationship between physiological system changes induced by exercise performed at HA is modulated by exercise intensity. [ABSTRACT FROM AUTHOR]

Aims: Low‐density lipoprotein cholesterol (LDL‐C), anaemia and low platelets have been associated with worse clinical outcomes in heart failure patients. We investigated the relationship between the combination of these three components and clinical outcome in patients with heart failure with preserved ejection fraction (HFpEF). Methods and results: We examined the data of 1021 patients with HFpEF hospitalized with acute decompensated heart failure (HF) from the PURSUIT‐HFpEF registry, a prospective, multicenter observational study. The enrolled patients were classified into four groups by an LEP (LDL‐C, Erythrocyte, and Platelet) score of 0 to 3 points, with 1 point each for LDL‐C, erythrocyte and platelet values less than the cut‐off values as calculated by receiver operating characteristic curve analysis. The endpoint, a composite of all‐cause death and HF readmission, was evaluated among the four groups. Median follow‐up duration was 579 [300, 978] days. Risk of the composite endpoint significantly differed among the four groups (P < 0.001). Kaplan–Meier analysis showed that the groups with an LEP score of 2 had higher risk of the composite endpoint than those with an LEP score of 0 or 1 (P < 0.001, and P = 0.013, respectively), while those with an LEP score of 3 had higher risk than those with an LEP score of 0, 1 or 2 (P < 0.001, P < 0.001 and P = 0.020, respectively). Cox proportional hazards analysis showed that an LEP score of 3 was significantly associated with the composite endpoint (P = 0.030). Kaplan–Meier analysis showed that risk of the composite of all‐cause death and HF readmission was significantly higher in low LDL values (less than the cut‐off values as calculated by receiver operating characteristic curve analysis) patients with statin use than in those without statin use (log rank P = 0.002). Conclusions: LEP score, which comprehensively reflects extra‐cardiac co‐morbidities, is significantly associated with clinical outcomes in HFpEF patients. [ABSTRACT FROM AUTHOR]

Various factors have a distinct impact on the quantity and dimensions of red blood cells across diverse animal species. These factors encompass age, sex, elevation, time of year, and lineage. The present study aimed to evaluate the influence of breed on the morphometric parameters of red blood cells in horses. To examine the impact of various horse breeds on the diameter, circumference, and surface area of red blood cells, blood samples were obtained from a total of 90 healthy horses. These horses belonged to three different breeds, including Arab Thoroughbred, English Thoroughbred, and Barbe. Each breed consisted of 30 individuals, with an equal distribution of males and females. The collected blood specimens were then divided into two separate batches for further analysis. The age range of all horses included in the study was between 5 and 12 years old. Smears were made and stained using the May-Grünwald Giemsa technique. The morphometric measurements were performed while using the OPTIKA™ Vision Pro special software. The obtained results showed that there were no significant differences in the red blood cell diameters across different horse breeds. However, this factor appears to influence significantly both the circumference and surface area of erythrocytes. Specifically, the circumference and surface of Barbe red blood cells were highly smaller than both Arabian and English purebred horses. The present study demonstrated that the circumference and surface of red blood cells appear to be more indicative and representative in detecting variations in the erythrocyte morphometry between different horse breeds. [ABSTRACT FROM AUTHOR]

Oxidative stress can damage tissues and cells, and their resilience or susceptibility depends on the robustness of their antioxidant mechanisms. The latter include small molecules, proteins, and enzymes, which are linked together in metabolic pathways. Red blood cells are particularly susceptible to oxidative stress due to their large number of hemoglobin molecules, which can undergo auto-oxidation. This yields reactive oxygen species that participate in Fenton chemistry, ultimately damaging their membranes and cytosolic constituents. Fortunately, red blood cells contain robust antioxidant systems to enable them to circulate and perform their physiological functions, particularly delivering oxygen and removing carbon dioxide. Nonetheless, if red blood cells have insufficient antioxidant reserves (e.g., due to genetics, diet, disease, or toxin exposure), this can induce hemolysis in vivo or enhance susceptibility to a "storage lesion" in vitro, when blood donations are refrigerator-stored for transfusion purposes. Ergothioneine, a small molecule not synthesized by mammals, is obtained only through the diet. It is absorbed from the gut and enters cells using a highly specific transporter (i.e., SLC22A4). Certain cells and tissues, particularly red blood cells, contain high ergothioneine levels. Although no deficiency-related disease has been identified, evidence suggests ergothioneine may be a beneficial "nutraceutical." Given the requirements of red blood cells to resist oxidative stress and their high ergothioneine content, this review discusses ergothioneine's potential importance in protecting these cells and identifies knowledge gaps regarding its relevance in enhancing red blood cell circulatory, storage, and transfusion quality. [ABSTRACT FROM AUTHOR]

IntroductionObesity is thought to be accompanied by chronic, low-grade, inflammation. The adipocytes are present in the subcutaneous and visceral fat tissue and contribute to the bone marrow cell compartment. Therefore, it poses a question whether the factors influencing adipocyte functions also have an impact on the hematopoietic function of the bone marrow. The aim of our study was to evaluate the association between erythrocyte parameters, the proinflammatory Th17 lymphocytes, and IR markers in children with excessive body weight.MethodsA total of 27 overweight/obese and 15 normal-weight children aged 8–18 years were enrolled in the study. The analysis included anthropometric measurements, evaluation of Th17 cell frequency, erythrocyte parameters, and carbohydrate metabolism parameters.ResultsIn overweight/obese children, erythrocyte count (p = 0.00002), hemoglobin (HGB) concentration (p = 0.005), and frequency of Th17 cells (p = 0.048) were higher. Anthropometric parameters correlated with erythrocyte parameters, as well as Th17 cell frequency in all children. The erythrocyte count correlated with the Th17 subset (p = 0.01, r = 0.38). Moreover, in all children, the correlation between erythrocyte and fasting insulin (FI) (p = 0.00005, r = 0.58), HOMA-IR (p = 0.00005, r = 0.58), and QUICKI (p = 0.000042, r = −0.59), as well as between HGB and FI (p = 0.037, r = 0.32), HOMA-IR (p = 0.37, r = 0.32), and QUICKI (p = 0.049, r = −0.31) was found. In the overweight/obese group, erythrocyte count correlated with insulin 2 h after the oral glucose tolerance test (OGTT) (p = 0.04, r = 0.4), while HGB correlated with glucose and insulin 2 h after OGTT (p = 0.018, r = 0.45; p = 0.04, r = 0.44, respectively).ConclusionsOur study confirmed that the erythrocyte parameters are higher in children with obesity and are positively correlated with insulin resistance and proinflammatory Th17 lymphocyte. Thus, it can be concluded that erythrocyte parameters reflect the risk of developing IR in response to chronic inflammation associated with obesity. These are simple, easily accessible, and repeatable tests that, in the assessment of obese patients, may herald the developing metabolic syndrome and serve as a helpful additional tool for assessing the effectiveness of treatment.

Background: Levofloxacin, a fluoroquinolone, is an extensively used antibiotic effective against both positively and negatively staining bacteria. It works by inhibiting bacterial topoisomerase type II and topoisomerase type IV, resulting in impaired DNA synthesis and bacterial cell death. Eryptosis is another term for apoptotic cell death of erythrocyte marked by cell shrinkage, phosphatidylserine (PS) flipping, and membrane blebbing. Methods: The intent of the present research was to look at the eryptotic effect of levofloxacin by exposing erythrocytes to therapeutical doses (7, 14 µM) of levofloxacin for 48 hours. Cell size evaluation, PS subjection to outside, and calcium channel inhibition were carried out to investigate eryptosis. Oxidative stress generated by levofloxacin was measured as a putative mechanism of eryptosis using glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase activities. Similarly, hemolysis measurements demonstrated levofloxacin’s cytotoxic effect. Results: Our findings showed that therapeutic doses of levofloxacin can cause a considerable decline in antioxidant enzymes activities, as well as induce cell shrinkage, PS externalization, and hemolysis in erythrocytes. The role of calcium in triggering erythrocyte shrinkage was also confirmed. Conclusion: In conclusion, our findings showed that the indicated levofloxacin doses caused oxidative stress, which leads to erythrocyte death via eryptosis and hemolysis. These findings emphasize the importance of using levofloxacin with caution and the need for additional research to mitigate these side effects.

Red blood cell (RBC)-derived systems offer a potential platform for delivery of biomedical cargos. Although the importance of specific proteins associated with the biodistribution and pharmacokinetics of these particles has been recognized, it remains to be explored whether some of the key transmembrane and cytoskeletal proteins responsible for immune-modulatory effects and mechanical integrity of the particles are retained. Herein, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and quantitative tandem mass tag mass spectrometry in conjunction with bioinformatics analysis, we have examined the proteomes of micro- and nanosized erythrocyte ghosts doped with indocyanine green and compared them with those of RBCs. We identified a total of 884 proteins in each set of RBCs, micro-, and nanosized particles, of which 8 and 45 proteins were expressed at significantly different relative abundances when comparing micro-sized particles vs RBCs and nanosized particles vs RBCs, respectively. We found greater differences in relative abundances of some mechano-modulatory proteins, such as band 3 and protein 4.2, and immunomodulatory proteins like CD44, CD47, and CD55 in nanosized particles as compared to RBCs. Our findings highlight that the methods utilized in fabricating RBC-based systems can induce substantial effects on their proteomes. Mass spectrometry data are available at ProteomeXchange with the identifier PXD038780.

The utilizations of microfluidic chips for single RBC (red blood cell) studies have attracted great interests in recent years to filter, trap, analyze, and release single erythrocytes for various applications. Researchers in this field have highlighted the vast potential in developing micro devices for industrial and academia usages, including lab-on-a-chip and organ-on-a-chip systems. This article critically reviews the current state-of-the-art and recent advances of microfluidics for single RBC analyses, including integrated sensors and microfluidic platforms for microscopic/tomographic/spectroscopic single RBC analyses, trapping arrays (including bifurcating channels), dielectrophoretic and agglutination/aggregation studies, as well as clinical implications covering cancer, sepsis, prenatal, and Sickle Cell diseases. Microfluidics based RBC microarrays, sorting/counting and trapping techniques (including acoustic, dielectrophoretic, hydrodynamic, magnetic, and optical techniques) are also reviewed. Lastly, organs on chips, multi-organ chips, and drug discovery involving single RBC are described. The limitations and drawbacks of each technology are addressed and future prospects are discussed.

Amyloid beta peptides (Aβ) have been identified as the main pathogenic agents in Alzheimer's disease (AD). Soluble Aβ 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 Aβ 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 Aβ in RBCs and suggest new therapeutic avenues in AD. [ABSTRACT FROM AUTHOR]

Garlic is known to have diverse effects on mammalian cells, being cytotoxic, especially to cancer cells, but also protect against oxidative stress. Mammalian erythrocyte is a simple cell devoid of intracellular organelles, protein synthesis ability, and most signaling pathways. Therefore, examination of the effects of garlic on erythrocytes allows for revealing primary events in the cellular action of garlic extract. In this study, human erythrocytes or erythrocyte membranes were exposed to garlic extract at various dilutions. Hemoglobin oxidation to methemoglobin, increased binding of hemoglobin to the membrane, and formation of Heinz bodies were observed. Garlic extract depleted acid-soluble thiols, especially glutathione, and induced a prooxidative shift in the cellular glutathione redox potential. The extract increased the osmotic fragility of erythrocytes, induced hemolysis, and inhibited hemolysis in isotonic ammonium chloride, indicative of decreased membrane permeability for Cl− and increased the membrane fluidity. Fluorescent probes indicated an increased level of reactive oxygen species and induction of lipid peroxidation, but these results should be interpreted with care since the extract alone induced oxidation of the probes (dichlorodihydrofluorescein diacetate and BODIPY C11). These results demonstrate that garlic extract induces oxidative changes in the erythrocyte, first of all, thiol and hemoglobin oxidation. [ABSTRACT FROM AUTHOR]

OBJECTIVE Determine the hemolytic effect of an 18-µm microaggregate blood filter during in vitro sea turtle whole blood transfusions as well as describe the average diameter of leatherback (Dermochelys coriacea) and Kemp’s ridley sea turtle (Lepidochelys kempii) RBCs. ANIMALS 5 green (Chelonia mydas), 5 loggerhead (Caretta caretta), and 5 Kemp’s ridley sea turtles (total n = 15). METHODS Heparinized sea turtle blood was infused at 60 mL/h through a microbore extension set without and then with a postsyringe, inline 18-µm microaggregate blood filter. Pre- and postfiltration PCV, Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations were measured. With the use of light microscopy and archived blood smears, the maximum and minimum diameter of 20 RBCs from each of the 5 leatherback and 5 Kemp’s ridley sea turtles were measured with a calibrated ocular micrometer using 400X magnification. RESULTS There were no significant differences between pre- and postfiltration samples for Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations; however, there was a significant median postfiltration decrease in PCV of approximately 4%, representing a 13% decrease of the total RBCs transfused. Average maximum diameters for leatherback and Kemp’s ridley sea turtle RBCs were 19.7 and 16.1 µm, respectively. CLINICAL RELEVANCE Although the 18-µm microaggregate blood filter does not hemolyze transfused sea turtle RBCs and is likely safe for in vivo blood transfusions, the filter’s pores may retain a small proportion of infused RBCs given their diameter. [ABSTRACT FROM AUTHOR]

Erythrocytes play a fundamental role in oxygen delivery to tissues and binding to inflammatory mediators. Evidences suggest that dysregulated erythrocyte function could contribute to the pathophysiology of several neurodegenerative diseases. We aimed to evaluate changes in morphological, biomechanical, and biophysical properties of erythrocytes from amyotrophic lateral sclerosis (ALS) patients, as new areas of study in this disease. Blood samples were collected from ALS patients, comparing with healthy volunteers. Erythrocytes were assessed using atomic force microscopy (AFM) and zeta potential analysis. The patients' motor and respiratory functions were evaluated using the revised ALS Functional Rating Scale (ALSFRS‐R) and percentage of forced vital capacity (%FVC). Patient survival was also assessed. Erythrocyte surface roughness was significantly smoother in ALS patients, and this parameter was a predictor of faster decline in ALSFRS‐R scores. ALS patients exhibited higher erythrocyte stiffness, as indicated by reduced AFM tip penetration depth, which predicted a faster ALSFRS‐R score and respiratory subscore decay. A lower negative charge on the erythrocyte membrane was predictor of a faster ALSFRS‐R and FVC decline. Additionally, a larger erythrocyte surface area was an independent predictor of lower survival. These changes in morphological and biophysical membrane properties of ALS patients' erythrocytes, lead to increased cell stiffness and morphological variations. We speculate that these changes might precipitate motoneurons dysfunction and accelerate disease progression. Further studies should explore the molecular alterations related to these observations. Our findings may contribute to dissect the complex interplay between respiratory function, tissue hypoxia, progression rate, and survival in ALS. [ABSTRACT FROM AUTHOR]

BACKGROUND: The triad "insulin resistance, prediabetes, diabetes" is three independent neologies with characteristic features and development. In addition, each are characterized by progression and the possibility of transition from one form to other. Due to the fact that diabetes is one of the common diseases associated with high rates of disability, it is necessary to improve diagnostic methods and educational regimens for successful prevention and treatment of the disease. OBJECTIVE: We investigated Band 3 protein (B3p) level, osmotic resistance of erythrocytes, the total antioxidant activity (TAA) of blood serum, level of HbA1 in group patients with insulin resistance (IR), prediabetes, and Type 2 Diabetes Mellitus (T2DM) and comparative with health control group. METHODS: We used original, accurate research methods that measure the essence of the studied quantities. RESULTS: Disruptions of glucose and insulin homeostasis ay lead to the initiation of oxidative stress (in our study demonstrated by a decrease of TAA of blood serum) increased redox-sensitive PTP activity and aberrant band 3 phosphorylation, potentially leading to reduced erythrocyte deformability. At the same time glycation of Hb during T2DM may affect its cross-link with membrane proteins, in particular with B3p, and although appears to limit its cross-linking and decrease its clusterization ability, induces alterations in the cytoskeletal matrix, and thereby decrease erythrocytes' osmotic resistance making them more susceptible to hemolysis. CONCLUSIONS: The osmotic resistance of the erythrocytes can be used as a sensitive marker for the detection of the early stages of hyperglycemia (prediabetes). This set of clinical trials will make it possible to identify diseases that make up the triad at an early stage. Early detection of disorders and continued research in this direction will help in the development of a diagnostic scheme for the prevention of such patients. Based on our data, research into anti-oxidation drugs is very important. With the help of the array of studies described in the article and antioxidant treatment, the likelihood of successful treatment will increase. [ABSTRACT FROM AUTHOR]

BACKGROUND: The triad "insulin resistance, prediabetes, diabetes" is three independent neologies with characteristic features and development. In addition, each are characterized by progression and the possibility of transition from one form to other. Due to the fact that diabetes is one of the common diseases associated with high rates of disability, it is necessary to improve diagnostic methods and educational regimens for successful prevention and treatment of the disease. OBJECTIVE: We investigated Band 3 protein (B3p) level, osmotic resistance of erythrocytes, the total antioxidant activity (TAA) of blood serum, level of HbA1 in group patients with insulin resistance (IR), prediabetes, and Type 2 Diabetes Mellitus (T2DM) and comparative with health control group. METHODS: We used original, accurate research methods that measure the essence of the studied quantities. RESULTS: Disruptions of glucose and insulin homeostasis ay lead to the initiation of oxidative stress (in our study demonstrated by a decrease of TAA of blood serum) increased redox-sensitive PTP activity and aberrant band 3 phosphorylation, potentially leading to reduced erythrocyte deformability. At the same time glycation of Hb during T2DM may affect its cross-link with membrane proteins, in particular with B3p, and although appears to limit its cross-linking and decrease its clusterization ability, induces alterations in the cytoskeletal matrix, and thereby decrease erythrocytes' osmotic resistance making them more susceptible to hemolysis. CONCLUSIONS: The osmotic resistance of the erythrocytes can be used as a sensitive marker for the detection of the early stages of hyperglycemia (prediabetes). This set of clinical trials will make it possible to identify diseases that make up the triad at an early stage. Early detection of disorders and continued research in this direction will help in the development of a diagnostic scheme for the prevention of such patients. Based on our data, research into anti-oxidation drugs is very important. With the help of the array of studies described in the article and antioxidant treatment, the likelihood of successful treatment will increase. [ABSTRACT FROM AUTHOR]

Pathological processes often change the mechanical properties of cells. Increased rigidity could be a marker of cellular malfunction. Erythrocytes are a type of cell that deforms to squeeze through tiny capillaries; changes in their rigidity can dramatically affect their functionality. Furthermore, differences in the homeostatic elasticity of the cell can be used as a tool for diagnosis and even for choosing the adequate treatment for some illnesses. More accurate types of equipment needed to study biomechanical phenomena at the single-cell level are very costly and thus out of reach for many laboratories around the world. This study presents a simple and low-cost technique to study the rigidity of red blood cells (RBCs) through the application of electric fields in a hand-made microfluidic chamber that uses a capacitor principle. As RBCs are deformed with the application of voltage, cells are observed under a light microscope. From mechanical force vs. deformation data, the elastic constant of the cells is determined. The results obtained with the capacitor-based method were compared with those obtained using optical tweezers, finding good agreement. In addition, P. falciparum-infected erythrocytes were tested with the electric field applicator. Our technique provides a simple means of testing the mechanical properties of individual cells. [ABSTRACT FROM AUTHOR]

Glycophorin A and glycophorin B are structural membrane glycoproteins bound in the band 3 multiprotein complexes on human red blood cells (RBCs). Band 3 is an erythroid-specific anion exchanger (AE1). AE1-mediated HCO3− transport provides the substrate for the enzyme-catalyzed conversion HCO3− (aq) # CO2(g), which takes place inside the RBCs. Bicarbonate transport via AE1 supports intravascular acid–base homeostasis and respiratory excretion of CO2. In the past decade, we conducted several comparative physiology studies on Taiwanese people having the glycophorin variant GPMur RBC type (which accompanies greater AE1 expression). We found that increased anion transport across the erythrocyte membrane not only enhances gas exchange and lung functions but also elevates blood pressure (BP) and reduces nitric oxide (NO)- dependent vasodilation and exhaled NO fraction (FeNO) in healthy individuals with GP.Mur. Notably, in people carrying the GPMur blood type, the BP and NO-dependent, flow-mediated vasodilation (FMD) are both more strongly correlated with individual hemoglobin (Hb) levels. As blood NO and nitrite (NO2− ) are predominantly scavenged by intraerythrocytic Hb, and NO2− primarily enters RBCs via AE1, could a more monoanion-permeable RBC membrane (i.e., GPMur/ increased AE1) enhance NO2− /NO3− permeability and Hb scavenging of NO2− and NO to affect blood pressure? In this perspective, a working model is proposed for the potential role of AE1 in intravascular NO availability, blood pressure, and clinical relevance. [ABSTRACT FROM AUTHOR]

Genital tract infections of various etiologies and anemia remain common in pregnant women. At present, there is a paucity of data on the impact of reproductive tract infections on the development of anemia in pregnant women, with particular emphasis on the contribution of eryptosis. The aim of the current study was to assess the ability of bacterial, viral and fungal reproductive tract infections to trigger eryptosis of circulating erythrocytes in pregnant women. Methods. The study included 47 pregnant women. According to the pathology of the infection, the patients were divided into three groups: 14 women with bacterial, 12 women with viral, 11 women with fungal infections of the reproductive tract and 10 pregnant women without extragenital and obstetric pathology (control subjects). The following methods were used to determine infection: bacteriologic, microscopic, polymerase chain reaction, immunoenzymatic, etc. Flow cytometry-based detection of eryptosis parameters (cell morphology, membrane phospholipid scrambling, and oxidative stress) was performed in pregnant women with reproductive tract infections of bacterial, viral, or fungal origin and in healthy individuals. Annexin V-FITC staining and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) staining were used to quantify phosphatidylserine exposure and reactive oxygen species (ROS) generation, respectively. Fluorescence was acquired using a BD FACSCanto™ II flow cytometer. ANOVA test was used to compare numerical data of eryptosis assays. Post-hoc Bonferroni test was applied afterwards. Data were processed by Graph Pad Prism 5.0 software (USA). The difference was considered statistically significant at p < 0.05. The research was conducted in accordance with the fundamental principles of Good Clinical Practice (GCP, 1996), the Council of Europe Convention on Human Rights and Biomedicine (April 4, 1997), the Helsinki Declaration of the World Medical Association on Ethical Principles for Medical Research Involving Human Subjects (1964-2008), as well as the Ministry of Health of Ukraine Order No. 690 dated September 23, 2009 (amended by the Ministry of Health of Ukraine Order No. 523 dated July 12, 2012). The research design was discussed and approved at the meeting of the Medical and Ethical Committee of the Kharkiv National Medical University (Protocol No. 19 dated May 19, 2024). The paper is an excerpt from the scientific research project of the Department of Obstetrics and Gynecology No. 2 at Kharkiv National Medical University, entitled «Optimisation of diagnostics, treatment of diseases of the reproductive system and pregnancy complications in women with extragenital pathology» (state registration number 0121U110923).) Results. Erythropoiesis parameters were evaluated in pregnant women with bacterial, viral and fungal reproductive tract infections. Pregnancy-associated bacterial reproductive tract infections were associated with increased phosphatidylserine externalization in circulating erythrocytes, without ROS accumulation or cell shrinkage. Erythrocytes from patients with genital tract infections of viral or fungal origin show no signs of eryptosis, such as cell membrane scrambling, oxidative stress, or changes in cell morphology. Conclusions. Reproductive tract infections of bacterial origin in pregnant women are associated with accelerated eryptosis, which may contribute to anemia in these women. Exclusively bacterial genital tract infection was shown to induce lipid membrane scrambling and hence eryptosis in erythrocytes from pregnant women. Phosphatidylserine externalization did not differ significantly between women with viral or fungal infections and healthy controls. Eryptosis induced by bacterial genital tract infection was not associated with cell shrinkage or ROS overproduction. [ABSTRACT FROM AUTHOR]

Magnetic activated cell sorting (MACS) is a well-known sperm selection technique, which is able to remove apoptotic spermatozoa from semen samples using the classic annexinV based method. Leukocytes and erythrocytes in semen samples or in testicular tissue processed for in vitro fertilization (IVF) could exert detrimental effects on sperm. In the current study, we rethought the aforementioned technique and used magnetic microbeads conjugated with anti-CD45/CD235a antibodies to eliminate contaminating leukocytes and erythrocytes from leukocytospermic semen samples and testicular tissue samples gained via testicular sperm extraction (TESE). With this technique, a 15.7- and a 30.8-fold reduction could be achieved in the ratio of leukocytes in semen and in the number of erythrocytes in TESE samples, respectively. Our results show that MACS is a method worth to reconsider, with more potential alternative applications. Investigations to find molecules labeling high-quality sperm population and the development of positive selection procedures based on these might be a direction of future research. [ABSTRACT FROM AUTHOR]

Background: Chemotherapies for malaria and babesiosis frequently succumb to the emergence of pathogen-related drug-resistance. Host-targeted therapies are thought to be less susceptible to resistance but are seldom considered for treatment of these diseases. Methods: Our overall objective was to systematically assess small molecules for host cell-targeting activity to restrict proliferation of intracellular parasites. We carried out a literature survey to identify small molecules annotated for host factors implicated in Plasmodium falciparum infection. Alongside P. falciparum, we implemented in vitro parasite susceptibility assays also in the zoonotic parasite Plasmodium knowlesi and the veterinary parasite Babesia divergens. We additionally carried out assays to test directly for action on RBCs apart from the parasites. To distinguish specific host-targeting antiparasitic activity from erythrotoxicity, we measured phosphatidylserine exposure and hemolysis stimulated by small molecules in uninfected RBCs. Results: We identified diverse RBC target-annotated inhibitors with Plasmodium-specific, Babesia-specific, and broad-spectrum antiparasitic activity. The anticancer MEK-targeting drug trametinib is shown here to act with submicromolar activity to block proliferation of Plasmodium spp. in RBCs. Some inhibitors exhibit antimalarial activity with transient exposure to RBCs prior to infection with parasites, providing evidence for host-targeting activity distinct from direct inhibition of the parasite. Conclusions: We report here characterization of small molecules for antiproliferative and host cell-targeting activity for malaria and babesiosis parasites. This resource is relevant for assessment of physiological RBC-parasite interactions and may inform drug development and repurposing efforts. [ABSTRACT FROM AUTHOR]

Epidemiological studies have suggested that inhalation exposure to particulate matter (PM) air pollution, especially fine particles (i.e., PM2.5 (PM with an aerodynamic diameter of 2.5 microns or less)), is causally associated with cardiovascular health risks. To explore the toxicological mechanisms behind the observed adverse health effects, the hemolytic activity of PM2.5 samples collected during different pollution levels in Beijing was evaluated. The results demonstrated that the hemolysis of PM2.5 ranged from 1.98% to 7.75% and demonstrated a clear dose–response relationship. The exposure toxicity index (TI) is proposed to represent the toxicity potential of PM2.5, which is calculated by the hemolysis percentage of erythrocytes (red blood cells, RBC) multiplied by the mass concentration of PM2.5. In a pollution episode, as the mass concentration increases, TI first increases and then decreases, that is, TI (low pollution levels) < TI (heavy pollution levels) < TI (medium pollution levels). In order to verify the feasibility of the hemolysis method for PM toxicity detection, the hemolytic properties of PM2.5 were compared with the plasmid scission assay (PSA). The hemolysis results had a significant positive correlation with the DNA damage percentages, indicating that the hemolysis assay is feasible for the detection of PM2.5 toxicity, thus providing more corroborating information regarding the risk to human cardiovascular health. [ABSTRACT FROM AUTHOR]

The search for protective substances that can be used during red blood cell thawing and the study of their effects on red blood cells contribute to increasing the number and quality of viable cells after the cryopreservation cycle. We studied the effect of posthypertonic shock and amphiphilic compounds on the shape and eryptosis of human erythrocytes. The method of flow cytometry was used, this allows analyzing two parameters simultaneously, which increases the efficiency of research. The shape was assessed by the sphericity index (SphI), and eryptosis by the redistribution of phosphatidylserine to the membrane outer surface. It has been shown that sodium decylsulfate and chlorpromazine reduce erythrocyte damage in posthypertonic shock by 3.6 and 4.2 times, respectively. Sodium decylsulfate helps to preserve the shape of cells (SphI coefficient remains the same), while when chlorpromazine is used, the shape changes towards spherical (SphI coefficient changes 2 times). The study of the level of Annexin V FITC binding to phosphatidylserine in outer layer of membrane revealed a concentration-dependent increase in fluorescence when sodium decylsulfate was used, indicating a disorder of the bilayer asymmetry. In contrast, chlorpromazine did not change the distribution of phosphatidylserine. Comparison of two parameters of cell viability - the sphericity coefficient and anexin binding - allowed us to choose the conditions that are optimal for the use of the studied protective substances. Namely, it is advisable to use the lowest effective concentration of sodium decylsulfate (200 mcmol/l) for protective purposes. This ensures the preservation of the cell shape and minimal impact on the membrane asymmetry [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Veteriner is the property of Fakultas Kedokteran Hewan, Universitas Udayana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Genital tract infections of various etiologies and anemia remain common in pregnant women. At present, there is a paucity of data on the impact of reproductive tract infections on the development of anemia in pregnant women, with particular emphasis on the contribution of eryptosis. The aim of the current study was to assess the ability of bacterial, viral and fungal reproductive tract infections to trigger eryptosis of circulating erythrocytes in pregnant women. Methods. The study included 47 pregnant women. According to the pathology of the infection, the patients were divided into three groups: 14 women with bacterial, 12 women with viral, 11 women with fungal infections of the reproductive tract and 10 pregnant women without extragenital and obstetric pathology (control subjects). The following methods were used to determine infection: bacteriologic, microscopic, polymerase chain reaction, immunoenzymatic, etc. Flow cytometry- based detection of eryptosis parameters (cell morphology, membrane phospholipid scrambling, and oxidative stress) was performed in pregnant women with reproductive tract infections of bacterial, viral, or fungal origin and in healthy individuals. Annexin V-FITC staining and 2’,7’-dichlorodihydrofl uorescein diacetate (H2DCFDA) staining were used to quantify phosphatidylserine exposure and reactive oxygen species (ROS) generation, respectively. Fluorescence was acquired using a BD FACSCanto™ II fl ow cytometer. ANOVA test was used to compare numerical data of eryptosis assays. Post-hoc Bonferroni test was applied afterwards. Data were processed by Graph Pad Prism 5.0 software (USA). The diff erence was considered statistically signifi cant at p < 0.05. The research was conducted in accordance with the fundamental principles of Good Clinical Practice (GCP, 1996), the Council of Europe Convention on Human Rights and Biomedicine (April 4, 1997), the Helsinki Declaration of the World Medical Association on Ethical Principles for Medical Research Involving Human Subjects (1964-2008), as well as the Ministry of Health of Ukraine Order No. 690 dated September 23, 2009 (amended by the Ministry of Health of Ukraine Order No. 523 dated July 12, 2012). The research design was discussed and approved at the meeting of the Medical and Ethical Committee of the Kharkiv National Medical University (Protocol No. 19 dated May 19, 2024). The paper is an excerpt from the scientifi c research project of the Department of Obstetrics and Gynecology No. 2 at Kharkiv National Medical University, entitled «Optimisation of diagnostics, treatment of diseases of the reproductive system and pregnancy complications in women with extragenital pathology» (state registration number 0121U110923).) Results. Erythropoiesis parameters were evaluated in pregnant women with bacterial, viral and fungal reproductive tract infections. Pregnancy- associated bacterial reproductive tract infections were associated with increased phosphatidylserine externalization in circulating erythrocytes, without ROS accumulation or cell shrinkage. Erythrocytes from patients with genital tract infections of viral or fungal origin show no signs of eryptosis, such as cell membrane scrambling, oxidative stress, or changes in cell morphology. Conclusions. Reproductive tract infections of bacterial origin in pregnant women are associated with accelerated eryptosis, which may contribute to anemia in these women. Exclusively bacterial genital tract infection was shown to induce lipid membrane scrambling and hence eryptosis in erythrocytes from pregnant women. Phosphatidylserine externalization did not diff er signifi cantly between women with viral or fungal infections and healthy controls. Eryptosis induced by bacterial genital tract infection was not associated with cell shrinkage or ROS overproduction.

Artificial blood is a type of liquid preparation with oxygen-loading capacity and can temporarily substitute some function of blood. The developed artificial blood can be divided into four categories: artificial synthetic hemoglobin, artificial red blood cells made from natural hemoglobin, perfluorocarbons, and stem cell-differentiated red blood cells. This review focuses on the domestic and foreign research progress of artificial blood in recent years, and discusses its clinical application value, development trend, and future research, in order to provide new ideas to the development the artificial blood products and promote clinical application.

The complete blood cell count (CBC) was screened in a group of 15 donkeys, of which 8 were of Asinara breed (oculocutaneous albinism type 1, OCA1) and 7 of Sardo breed (gray coat). All donkeys were kept under same management and dietary conditions and underwent periodic health monitoring in the month of June 2024, at the peak of the positive photoperiod, at Mediterranean latitudes. One aliquot of whole blood, drawn from each individual into K2-EDTA containing tubes, was analyzed for the complete blood cell count through an automatic analyzer, within two hours of sampling. Data were analyzed and compared by one-way ANOVA, where the breed was an independent variable. All animals appeared clinically healthy, though mild eosinophilia was observed in Sardo donkeys. The red blood cell line showed peculiar traits for Asinara donkeys, which displayed significantly higher circulating red blood cell numbers than gray coat Sardo donkeys (RBC, 5.19 vs. 3.80 1012/mL ± 0.98 pooled-St. Dev, respectively; p = 0.017). RBCs also exhibited a smaller diameter and higher degree of anisocytosis in Asinara donkeys, along with lower hematocrit value, albeit within physiological ranges. Taken all together, such hematological profile depicts a peculiar trait of the red blood cell line in albino donkeys during the positive photoperiod.

Introduction: High-altitude polycythemia (HAPC) is a common chronic highaltitude disease characterized by significantly increased erythrocyte, hemoglobin (Hb), and hematocrit values and decreased arterial oxygen saturation. The mechanisms underlying HAPC development are unclear; we aimed to investigate this in an HAPC rat model. Methods: Twelve Sprague-Dawley rats were divided into control and HAPC groups. The HAPC group was exposed to hypobaric hypoxia. This HAPC model was assessed using routine blood tests and blood gas analyses. Bone marrow, peripheral blood reticulocytes (RETs), and peripheral blood erythrocyte apoptosis were measured using flow cytometry. Erythrocyte osmotic fragility (EOF) tests were conducted. Abnormal erythrocytes were counted using electron microscopy. Plasma-free hemoglobin, 5'-nucleotidase (CD73), adenosine, erythrocyte cytosolic adenosine, sphingosine-1-phosphate (S1P), and 2,3-bisphosphoglycerate (BPG) levels were measured using enzyme-linked immunosorbent assays. Erythrocyte metabolic pathway-related protein [adenosine A2B receptor (ADORA2B), erythrocyte equilibrative nucleoside transporter 1 (eENT1), sphingosine kinase 1 (SPHK1), phospho-SPHK1, bisphosphoglycerate mutase (BPGM), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH)] levels were assessed by Western blotting. Results: The HAPC rat model was successfully established (Hb > 210 g/L). Indices of bone marrow and peripheral blood RET proportions were significantly higher in the HAPC than the control group (p = 0.04 and p < 0.001, respectively). The proportion of peripheral blood erythrocytes in early apoptosis was significantly lower in the HAPC than the control group (p < 0.001). Vesicular erythrocyte and acanthocyte proportions were significantly higher in the HAPC than the control group (p < 0.001 and p = 0.019, respectively). The EOF tests revealed that 50% erythrocyte hemolysis occurred at 4.0-4.5 and 4.5-5.0 g/L NaCl in the control and HAPC groups, respectively. Plasma-free hemoglobin, CD73, adenosine, erythrocyte cytosolic adenosine, S1P, and 2,3-BPG levels and ADORA2B, eENT1, phospho-SPHK1, S1P, BPGM, and GAPDH erythrocyte expression levels (all p = 0.02) were significantly higher in the HAPC than the control group. Conclusion: In model rats, an HAPC-related erythrocyte increase was associated with enhanced bone marrow hematopoietic function and reduced erythrocyte apoptosis, whereas numerous abnormal erythrocytes, increased EOF, and reduced hemolysis resistance were associated with erythrocyte metabolism. CD73/adenosine/S1P/2,3-BPG and eENT1/adenosine/BPGM/2,3-BPG metabolic pathways in erythrocytes were activated in HAPC rats, facilitating oxygen release. These findings further reveal the intrinsic HAPC mechanism and forms a basis for future development of preventive and therapeutic strategies for HAPC. [ABSTRACT FROM AUTHOR]

Coupling red blood cell (RBC) supply to O2 demand is an intricate process requiring O2 sensing, generation of a stimulus, and signal transduction that alters upstream arteriolar tone. Although actively debated, this process has been theorized to be induced by hypoxia and to involve activation of endothelial inwardly rectifying K+ channels (KIR) 2.1 by elevated extracellular K+ to trigger conducted hyperpolarization via connexin40 (Cx40) gap junctions to upstream resistors. This concept was tested in resting healthy skeletal muscle of Cx40-/- and endothelial KIR2.1-/- mice using state-of-the-art live animal imaging where the local tissue O2 environment was manipulated using a custom gas chamber. Second-by-second capillary RBC flow responses were recorded as O2 was altered. A stepwise drop in PO2 at the muscle surface increased RBC supply in capillaries of control animals while elevated O2 elicited the opposite response; capillaries were confirmed to express Cx40. The RBC flow responses were rapid and tightly coupled to O2; computer simulations did not support hypoxia as a driving factor. In contrast, RBC flow responses were significantly diminished in Cx40-/- mice. Endothelial KIR2.1-/- mice, on the other hand, reacted normally to O2 changes, even when the O2 challenge was targeted to a smaller area of tissue with fewer capillaries. Conclusively, microvascular O2 responses depend on coordinated electrical signaling via Cx40 gap junctions, and endothelial KIR2.1 channels do not initiate the event. These findings reconceptualize the paradigm of blood flow regulation in skeletal muscle and how O2 triggers this process in capillaries independent of extracellular K+. [ABSTRACT FROM AUTHOR]

Plasmodium parasites need to find red blood cells (RBCs) that, on the one hand, expose receptors for the pathogen ligands and, on the other hand, maintain the right geometry to facilitate merozoite attachment and entry into the red blood cell. Both characteristics change with the maturation of erythrocytes. Some Plasmodia prefer younger vs. older erythrocytes. How does the life evolution of the RBC affect the invasion of the parasite? What happens when the RBC ages? In this review, we present what is known up until now. [ABSTRACT FROM AUTHOR]

Critically ill children are at risk of micronutrient deficiencies, which might lead to poor clinical outcomes. However, the interpretation of micronutrient concentrations in plasma is complicated due to age-dependent and critical illness-dependent changes. Certain red blood cell (RBC) concentrations might reflect the overall body status more reliably than plasma levels in the presence of systemic inflammatory response. This study longitudinally examined micronutrient concentrations in both plasma and RBC in critically ill children. This secondary analysis of the PEPaNIC RCT investigated the impact of early versus late initiation of parenteral macronutrient supplementation in critically ill children. All children received micronutrients when EN was insufficient (<80 % energy requirements). Blood samples were obtained on days 1, 3, 5 and 7 of Paediatric Intensive Care Unit (PICU) admission. Inductively coupled plasma mass spectrometry was used to measure zinc, selenium, and copper in plasma and selenium, copper, and magnesium in RBCs. Plasma magnesium was measured with colorimetric detection. Micronutrient concentrations were compared with age-specific reference values in healthy children and expressed using Z-scores. Changes in micronutrient concentrations over time were examined using the Friedman and post hoc Wilcoxon signed-rank tests. For 67 critically ill children, median (Q1; Q3) age 9.5 (5.5; 13.2) years, PIM3 score −2.3 (−3.1; −0.8), samples were available at various time points during their PICU stay. For 22 patients, longitudinal samples were available. On day 1, the median plasma Z-score for zinc was −5.2 (−5.2; −2.9), copper −1.6 (−2.9; −0.2), selenium −2.6 (−3.8; −1.0), magnesium −0.2 (−1.6; 1.3), and median RBC Z-score for copper was 0.5 (−0.1; 1.3), selenium −0.3 (−1.1; 0.7), magnesium 0.2 (−0.4; 1.3). In the longitudinal analysis, plasma zinc was significantly higher on day 5 (Z-score −3.2 (−4.6; −1.4)) than on day 1 (Z-score −5.2 (−5.2; −3.0), p = 0.032), and plasma magnesium was significantly higher on day 3 (Z-score 1.1 (−0.7; 4.0)) than on day 1 (Z-score −0.3 (−1.6; 0.5), p = 0.018). Plasma copper and selenium remained stable, and the RBC concentrations of all micronutrients remained stable during the first five days. Most patients had low plasma zinc, copper and selenium concentrations in the first week of their PICU stay, whereas they had normal to high RBC concentrations. More research is needed to examine the relationships between micronutrients and clinical outcome. [ABSTRACT FROM AUTHOR]

Human babesiosis is a potentially fatal tick-borne disease caused by intraerythrocytic Babesia parasites. The emergence of resistance to recommended therapies highlights the need for new and more effective treatments. Here we demonstrate that the 8-aminoquinoline antimalarial drug tafenoquine inhibits the growth of different Babesia species in vitro, is highly effective against Babesia microti and Babesia duncani in mice and protects animals from lethal infection caused by atovaquone-sensitive and -resistant B. duncani strains. We further show that a combination of tafenoquine and atovaquone achieves cure with no recrudescence in both models of human babesiosis. Interestingly, elimination of B. duncani infection in animals following drug treatment also confers immunity to subsequent challenge. Altogether, the data demonstrate superior efficacy of tafenoquine plus atovaquone combination over current therapies for the treatment of human babesiosis and highlight its potential in providing protective immunity against Babesia following parasite clearance. [ABSTRACT FROM AUTHOR]