Life and Death of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficient Erythrocytes - Role of Redox Stress and Band 3 Modifications

Delineation of the role of G6PD in Alzheimer's disease and potential enhancement through microfluidic and nanoparticle approaches

Alzheimer's disease (AD) is a neurodegenerative pathologic entity characterized by the abnormal presence of tau and macromolecular Aβ deposition that leads to the degeneration or death of neurons. In addition to that, glucose-6-phosphate dehydrogenase (G6PD) has a multifaceted role in the process of AD development, where it can be used as both a marker and a target. G6PD activity is dysregulated due to its contribution to oxidative stress, neuroinflammation, and neuronal death. In this context, the current review presents a vivid depiction of recent findings on the relationship between AD progression and changes in the expression or activity of G6PD. The efficacy of the proposed G6PD-based therapeutics has been demonstrated in multiple studies using AD mouse models as representative animal model systems for cognitive decline and neurodegeneration associated with this disease. Innovative therapeutic insights are made for the boosting of G6PD activity via novel innovative nanotechnology and microfluidics tools in drug administration technology. Such approaches provide innovative methods of surpassing the blood-brain barrier, targeting step-by-step specific neural pathways, and overcoming biochemical disturbances that accompany AD. Using different nanoparticles loaded with G6DP to target specific organs, e.g., G6DP-loaded liposomes, enhances BBB penetration and brain distribution of G6DP. Many nanoparticles, which are used for different purposes, are briefly discussed in the paper. Such methods to mimic BBB on organs on-chip offer precise disease modeling and drug testing using microfluidic chips, requiring lower sample amounts and producing faster findings compared to conventional techniques. There are other contributions to microfluid in AD that are discussed briefly. However, there are some limitations accompanying microfluidics that need to be worked on to be used for AD. This study aims to bridge the gap in understanding AD with the synergistic use of promising technologies; microfluid and nanotechnology for future advancements.

Should the standard model of cellular energy metabolism be reconsidered? Possible coupling between the pentose phosphate pathway, glycolysis and extra-mitochondrial oxidative phosphorylation

The process of cellular respiration occurs for energy production through catabolic reactions, generally with glucose as the first process step. In the present work, we introduce a novel concept for understanding this process, based on our conclusion that glucose metabolism is coupled to the pentose phosphate pathway (PPP) and extra-mitochondrial oxidative phosphorylation in a closed-loop process. According to the current standard model of glycolysis, glucose is first converted to glucose 6-phosphate (glucose 6-P) and then to fructose 6-phosphate, glyceraldehyde 3-phosphate and pyruvate, which then enters the Krebs cycle in the mitochondria. However, it is more likely that the pyruvate will be converted to lactate. In the PPP, glucose 6-P is branched off from glycolysis and used to produce NADPH and ribulose 5-phosphate (ribulose 5-P). Ribulose 5-P can be converted to fructose 6-P and glyceraldehyde 3-P. In our view, a circular process can take place in which the ribulose 5-P produced by the PPP enters the glycolysis pathway and is then retrogradely converted to glucose 6-P. This process is repeated several times until the complete degradation of glucose 6-P. The role of mitochondria in this process is to degrade lipids by beta-oxidation and produce acetyl-CoA; the function of producing ATP appears to be only secondary. This proposed new concept of cellular bioenergetics allows the resolution of some previously unresolved controversies related to cellular respiration and provides a deeper understanding of metabolic processes in the cell, including new insights into the Warburg effect.

Adverse hematological profiles associated with chlorpromazine antipsychotic treatment in male rats: Preventive and reversal mechanisms of taurine and coenzyme-Q10

Chlorpromazine (CPZ) is one of the most effective antipsychotic drugs used for managing psychotic related disorders owing to its dopamine receptor blocking action. However, pharmacological investigations against CPZ's cytotoxic effect have remained scarce. Hence, this study investigated the preventive and reversal effects of taurine and coenzyme-Q10 (COQ-10), which are compounds with proven natural antioxidant properties, against CPZ-induced hematological impairments in male rats. In the preventive study, rats received oral saline (10 ml/kg), taurine (150 mg/kg/day), COQ-10 (10 mg/kg/day) or in combination for 56 days, alongside CPZ (30 mg/kg, p.o.) between days 29-56. In the reversal protocol, rats had CPZ repeatedly for 56 days before taurine and COQ-10 treatments or their combination from days 29-56. Rats were also given taurine (150 mg/kg/day), and COQ-10 (10 mg/kg/day) alone for 56 days. Serums were extracted and assayed for hematological, with oxidative and inflammatory markers. CPZ induced decreased red/white blood cells, erythropoietin, platelet count, packed cell volume and hemoglobin, neutrophil, and lymphocyte, which were prevented and reversed by taurine and COQ-10, or their combination. Taurine and COQ-10 improved mean corpuscular volume, hemoglobin concentration, with increased erythropoietin levels relative to CPZ groups. CPZ-induced increased malondialdehyde, tumor necrosis factor-alpha and interleukin-6 levels with decreased interleukin-10, glutathione, and superoxide-dismutase were prevented and reversed by taurine and COQ-10 in comparison with CPZ groups. Taurine and COQ-10 alone notably improved the antioxidant/anti-inflammatory status relative to controls. Among other mechanisms, taurine and COQ-10 abated CPZ-induced hematological deficiencies, via decreased serum levels of oxidative stress, and pro-inflammatory cytokines release, with increased antioxidants and anti-inflammation function.

Plasmodium vivax Malaria and G6PD Testing

Early malaria investigators were certainly correct in classifying the species falciparum and the species vivax as belonging to the same genus, Plasmodium [...].

Parents' Awareness and Knowledge of G6PD Deficiency in the Eastern Province Saudi Arabia: A Cross-Sectional Study

Background Glucose-6-phosphate dehydrogenase deficiency, known as G6PD deficiency, is a common hematological disease in the Eastern Province. The presence of Glucose-6-phosphate dehydrogenase enzyme in the erythrocyte is crucial, as it aids in the protection of RBCs by preventing cellular damage. It was found that more than 400 million people in the world lack this enzyme, making it the most common enzyme deficiency worldwide. Because of the high prevalence of the disease in the world and the paucity of research in Saudi Arabia about G6PD deficiency, the idea of examining and assessing the awareness and knowledge of parents who have children affected with G6PD emerged. Objective This study aimed to evaluate parental knowledge regarding G6PD deficiency, identify the common and spread misconceptions regarding the disease, provide general insight for physicians about parental knowledge, and propose strategies to educate parents about G6PD deficiency. Methods This cross-sectional study was conducted from September 2022 to May 2023 on 459 individuals from the Eastern Province, Saudi Arabia. Using a questionnaire, parents with variable education levels and incomes participated. The questionnaire was available in both Arabic and English. The study aimed to gather comprehensive data regarding parental awareness and knowledge of G6PD deficiency, it focused on evaluating levels of awareness, knowledge, and misinformation of the participants. Data were analyzed by using Statistical Package for the Social Sciences, ver 22 (IBM Corp., Armonk, NY). The chi-square test was applied to check any association between demographics and level of knowledge (Good and Poor). Multiple logistic regression analysis was performed on significant demographic variables and an odds ratio with a 95% confidence interval was calculated. P < 0.05 was considered statistically significant. Results The study included a total of 459 participants, 309 (67.3%) were females and 150 (32.7%) were males. Regarding the demographics, the majority of the participants were <40 years old (61.9%), Saudi (99.3%), married (98.5%), having bachelor's/diploma level or above (Master/PhD) (76.9%), having inherited disorder (44.2%), and having a family history of chronic diseases (82.6%). Furthermore, regarding the knowledge of the disease, the majority of the participants who recognized the disease (82.1%) were familiar with the term fava bean anemia rather than it being called G6PD deficiency anemia. On the other hand, 73.2% of the participants were unable to recognize the disease and had never heard of G6PD deficiency anemia. In addition, the majority of participants had deficient information regarding medication triggers (61.4%), whether the gender of a person is linked to G6PD (77.5%), and whether both parents must be carriers to have a child with G6PD deficiency anemia (50.9%). Female respondents proved to be more knowledgeable regarding this topic as 57.9% of them showed good knowledge as compared to (44.7%) of the male subjects. Conclusion There are discrepancies in the level of awareness among research participants. Our result indicates the need for educational interventions regarding the nomenclature, medication triggers, inheritance mode and its relation to gender, and the symptoms of the disease and its severity. Therefore, it is advised to spread awareness in the eastern province through brochures, medical campaigns, and by healthcare professionals in different medical organizations.

From ancient crop to modern superfood: Exploring the history, diversity, characteristics, technological applications, and culinary uses of Peruvian fava beans

The search for plant-based superfoods has shown that many regional populations already have these foods in their diet, with significant potential for production and marketing. This critical review intends to show the history, diversity, characteristics, and uses, emphasizing their significance in traditional diets and potential in the food industry of Peruvian fava beans. As a valuable plant-based protein source, fava beans offer essential micronutrients and have diverse culinary applications. Innovative food industry applications include plant-based meat alternatives, fortified gluten-free products, and a natural color, protein, and fiber source in extruded foods. Key studies have highlighted the successful incorporation of fava beans into various food products, improving their nutritional properties, though some studies also point to limitations in their sensory acceptance. Further research is needed to understand the bioactive components, health effects, and techno-functional characteristics of beans. Challenges facing cultivating and consuming fava beans in Peru include adapting to climate change, enhancing productivity and quality, and promoting consumption and added value. Addressing these challenges involves developing climate-resilient varieties, optimizing agricultural practices, and providing access to resources and financing. In conclusion, this review highlights the promising prospects of Peruvian fava beans as a sustainable, nutritionally rich, and versatile ingredient in the food industry. By harnessing their potential and overcoming challenges, Peruvian fava beans can transition from an ancient crop to a modern superfood, inspiring a global shift towards sustainable and nutritionally balanced diets, aiding the fight against malnutrition, and enriching culinary traditions worldwide.

Fluoroquinolone-Based Organic Salts (GUMBOS) with Antibacterial Potential

Antimicrobial resistance is a silent pandemic considered a public health concern worldwide. Strategic therapies are needed to replace antibacterials that are now ineffective. One approach entails the use of well-known antibacterials along with adjuvants that possess non-antibiotic properties but can extend the lifespan and enhance the effectiveness of the treatment, while also improving the suppression of resistance. In this regard, a group of uniform materials based on organic salts (GUMBOS) presents an alternative to this problem allowing the combination of antibacterials with adjuvants. Fluoroquinolones are a family of antibacterials used to treat respiratory and urinary tract infections with broad-spectrum activity. Ciprofloxacin and moxifloxacin-based GUMBOS were synthesized via anion exchange reactions with lithium and sodium salts. Structural characterization, thermal stability and octanol/water partition ratios were evaluated. The antibacterial profiles of most GUMBOS were comparable to their cationic counterparts when tested against Gram-positive S. aureus and Gram-negative E. coli, except for deoxycholate anion, which demonstrated the least effective antibacterial activity. Additionally, some GUMBOS were less cytotoxic to L929 fibroblast cells and non-hemolytic to red blood cells. Therefore, these agents exhibit promise as an alternative approach to combining drugs for treating infections caused by resistant bacteria.

Prevalence and Risk Factors of Neonatal Hyperbilirubinemia in a Semi-Rural Area of the Democratic Republic of Congo: A Cohort Study

Neonatal hyperbilirubinemia (NH) is a frequent condition that, if left untreated, can lead to neurological disability and death. We assessed the prevalence of NH and associated neonatal and maternal risk factors in 362 mothers and 365 newborns in a semi-rural area of the Democratic Republic of Congo. In addition, we explored the knowledge and practices of mothers regarding this condition. We collected demographic data, anthropometric data, and obstetric and medical anamneses. We examined newborns at birth and at 24, 48, and 72 hours and measured bilirubin at birth in umbilical cord and capillary blood and thereafter in capillary blood. Hemoglobin, hematocrit, ABO group, Rhesus factor, glucose-6-phosphate dehydrogenase (G6PD) deficiency, Hemoglobin S (HbS), and malaria were assessed in mothers and newborns. Among 296 newborns (all time points available), 5.7% developed NH (95% CI: 3.4-9.0) between 24 and 72 hours according to National Institute for Health and Care Excellence (NICE) UK guidelines. There was a significantly higher risk in newborns with G6PD deficiency (homo- and hemizygous adjusted Odd Ratio [aOR]: 21.0, 95% CI: 4.1-105.9), preterm births (aOR: 6.1, 95% CI: 1.4-26.9), newborns with excessive birth weight loss (aOR: 5.8, 95% CI: 1.4-23.2), and hyperbilirubinemia at birth (aOR: 14.8, 95% CI: 2.7-79.6). Newborns with feto-maternal ABO incompatibility and G6PD deficiency had significantly higher bilirubin at birth than others. More than 60% of mothers had adequate knowledge of NH, but compliance with phototherapy in the absence of symptoms was low. Although risk factors for NH are common in this area, prevalence was not high, suggesting a need for better case definition. Implementation of point-of-care devices for diagnosis and awareness programs on risk prevention could help reduce neonatal morbidity and mortality associated with hyperbilirubinemia in these areas.

Impaired Enzymatic Antioxidant Defense in Erythrocytes of Rats with Ammonia-Induced Encephalopathy: Role of NMDA Receptors

Hepatic encephalopathy (HE), a neuropsychiatric disorder developing in patients with severe hepatic dysfunction, has been known for more than a century. However, pathogenetic mechanisms of cerebral dysfunction associated with liver disease are still poorly understood. There is a consensus that the primary cause of HE is accumulation of ammonia in the brain as a result of impaired liver detoxification capacity or the portosystemic shunt. Current evidence suggests that ammonia toxicity is mediated by hyperactivation of glutamate receptors, mainly N-methyl-D-aspartate receptors (NMDARs), and affects brain aerobic metabolism, which provides energy for multiple specific functions and neuronal viability. Recent reports on the presence of functional NMDARs in erythrocytes and the data on the deviations of blood parameters from their normal ranges indicate impaired hemodynamics and reduced oxygen-carrying capacity of erythrocytes in most patients with HE, thus suggesting a relationship between erythrocyte damage and cerebral dysfunction. In order to understand how hyperammonemia (HA)-induced disturbances in the energy metabolism in the brain (which needs a constant supply of large amounts of oxygen in the blood) lead to encephalopathy, it is necessary to reveal ammonia-induced impairments in the energy metabolism and antioxidant defense system of erythrocytes and to explore a potential role of ammonia in reduced brain oxygenation. To identify the said missing link, the activities of antioxidant enzymes and concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), and H2O2 were measured in the erythrocytes of rats with HA that were injected with the noncompetitive NMDAR antagonist MK-801. We found that in rats with HA, ammonia was accumulated in erythrocytes (cells lacking ammonia removal enzymes), which made them more susceptible to the prooxidant environment created during oxidative stress. This effect was completely or partially inhibited by MK-801. The data obtained might help to identify the risk factors in cognitive disorders and facilitate prediction of unfavorable outcomes of hypoperfusion in patients with a blood elevated ammonia concentration.

Correlating nanoscale motion and ATP production in healthy and favism erythrocytes: a real-time nanomotion sensor study

Introduction

Red blood cells (RBCs) are among the simplest, yet physiologically relevant biological specimens, due to their peculiarities, such as their lack of nucleus and simplified metabolism. Indeed, erythrocytes can be seen as biochemical machines, capable of performing a limited number of metabolic pathways. Along the aging path, the cells' characteristics change as they accumulate oxidative and non-oxidative damages, and their structural and functional properties degrade.

Methods

In this work, we have studied RBCs and the activation of their ATP-producing metabolism using a real-time nanomotion sensor. This device allowed time-resolved analyses of the activation of this biochemical pathway, measuring the characteristics and the timing of the response at different points of their aging and the differences observed in favism erythrocytes in terms of the cellular reactivity and resilience to aging. Favism is a genetic defect of erythrocytes, which affects their ability to respond to oxidative stresses but that also determines differences in the metabolic and structural characteristic of the cells.

Results

Our work shows that RBCs from favism patients exhibit a different response to the forced activation of the ATP synthesis compared to healthy cells. In particular, the favism cells, compared to healthy erythrocytes, show a greater resilience to the aging-related insults which was in good accord with the collected biochemical data on ATP consumption and reload.

Conclusion

This surprisingly higher endurance against cell aging can be addressed to a special mechanism of metabolic regulation that permits lower energy consumption in environmental stress conditions.

Energy and phosphorus utilization of pulses fed to broiler chickens

Energy and P utilization in faba beans and peas were evaluated in 3 broiler chicken experiments. In Exp. 1, 240 birds were allotted to 5 diets in a randomized complete block design with BW as a blocking factor on d 18 post hatching to determine the regression-derived energy utilization of faba beans (FB) and field peas (FP). In each of the respective Exp. 2 and 3, regression-derived P utilization in FB and FP were determined with 162 birds assigned to each of 3 diets in a randomized complete block design with BW as a blocking factor on d 19 post hatching. There were 8 replicate cages with 6 birds per cage in Exp. 1, and 6 replicate cages with 9 birds per cage in Exp. 2 and 3. The test ingredients were added to a corn-soybean meal-based diet at 15% or 30% in Exp. 1, whereas FB was included at 21%, 42%, or 63% and FP at 16%, 32%, or 48% in Exp. 2 and 3, respectively. In Exp. 1, the apparent ileal digestibility (AID) of gross energy (GE) and the ileal digestible energy (IDE) in the diets decreased linearly (P < 0.01). There was a quadratic response or a linear decrease (P < 0.05) with increasing concentrations of FB or FP, respectively, on the apparent total tract utilization (ATTU) of GE, metabolizable energy (ME), and nitrogen-corrected ME (MEn). The respective IDE, ME, and MEn determined were 2,541, 2,628, and 2,394 kcal/kg DM in FB and 2,254, 2,540, and 2,331 kcal/kg DM in FP. In Exp. 2 and 3, the ileal digestible and retainable P intake were linearly increased (P < 0.01). The estimated true ileal digestibility and true total tract utilization of P in FB were 66.5% and 66.7%, respectively. The respective corresponding values for FP were 73.4% and 73.8%. In conclusion, the information on utilization of energy and P in FB and FP provided could enhance proper diet formulation when using these ingredients.

Aging Injury Impairs Structural Properties and Cell Signaling in Human Red Blood Cells; Açaì Berry Is a Keystone

Red blood cell (RBC) deformability is the ability of cells to modulate their shape to ensure transit through narrow capillaries of the microcirculation. A loss of deformability can occur in several pathological conditions, during natural RBC aging through an increase in membrane protein phosphorylation, and/or through the structural rearrangements of cytoskeletal proteins due to oxidative conditions, with a key role played by band 3. Due to the close relationship between aging and oxidative stress, flavonoid-rich foods are good candidates to counteract age-related alterations. This study aims to verify the beneficial role of Açaì extract in a d-Galactose (d-Gal)-induced model of aging in human RBCs. To this end, band 3 phosphorylation and structural rearrangements in membrane cytoskeleton-associated proteins, namely spectrin, ankyrin, and/or protein 4.1, are analyzed in RBCs treated with 100 mM d-Gal for 24 h, with or without pre-incubation with 10 μg/mL Açaì extract for 1 h. Furthermore, RBC deformability is also measured. Tyrosine phosphorylation of band 3, membrane cytoskeleton-associated proteins, and RBC deformability (elongation index) are analyzed using western blotting analysis, FACScan flow cytometry, and ektacytometry, respectively. The present data show that: (i) Açaì berry extract restores the increase in band 3 tyrosine phosphorylation and Syk kinase levels after exposure to 100 mM d-Gal treatment; and (ii) Açaì berry extract partially restores alterations in the distribution of spectrin, ankyrin, and protein 4.1. Interestingly, the significant decrease in membrane RBC deformability associated with d-Gal treatment is alleviated by pre-treatment with Açaì extract. These findings further contribute to clarify mechanisms of natural aging in human RBCs, and propose flavonoid substances as potential natural antioxidants for the treatment and/or prevention of oxidative-stress-related disease risk.

Glucose 6 phosphate dehydrogenase deficiency quantitative test in dried blood spot- a potential marker for adult unknown G6PD deficiency

Glucose 6 Phosphate Dehydrogenase (G6PD) enzyme activity estimation in a freshly collected blood sample is the most widely used diagnostic method for the diagnosis of G6PD deficiency. The objective is to evaluate the need for newborn screening for G6PD deficiency over post-malarial diagnosis and the feasibility and reliability of using dried blood spots (DBS) as samples for screening. A total of 562 samples were analyzed for G6PD and parallel measurement of G6PD activity by the colorimetric method in whole blood and DBS was carried out in the neonatal subset. Among 466 adults, 27 (5.7%) showed G6PD deficiency, out of whom 22 (81.48%) were diagnosed after the malarial encounter. In the pediatric group, 8 neonates showed G6PD deficiency. G6PD activity estimated from DBS samples agreed with whole blood, with a statistically significant strong positive correlation. Screening of G6PD deficiency at birth to prevent future unwarranted complications, using DBS is feasible.

Surprising Structural and Functional Properties of Favism Erythrocytes Are Linked to Special Metabolic Regulation: A Cell Aging Study

Favism uniquely arises from a genetic defect of the Glucose-6 Phosphate Dehydrogenase (G6PD) enzyme and results in a severe reduction of erythrocytes' (RBCs) reducing power that impairs the cells' ability to respond to oxidative stresses. After exposure to fava beans or a few other drugs, the patients experience acute hemolytic anemia due to RBCs' lysis both intra and extra-vascularly. In the present paper, we compared selected biochemical, biophysical, and ultra-morphological properties of normal RBCs and cells from favism patients measured along cellular aging. Along the aging path, the cells' characteristics change, and their structural and functional properties degrade for both samples, but with different patterns and effectors that have been characterized in biophysical and biochemical terms. In particular, the analysis revealed distinct metabolic regulation in G6DP-deficient cells that determines important peculiarities in the cell properties during aging. Remarkably, the initial higher fragility and occurrence of structural/morphological alterations of favism cells develop, with longer aging times, into a stronger resistance to external stresses and higher general resilience. This surprisingly higher endurance against cell aging has been related to a special mechanism of metabolic regulation that permits lower energy consumption in environmental stress conditions. Our results provided a direct and coherent link between the RBCs' metabolic regulation and the cell properties that would not have been possible to establish without an investigation performed during aging. The consequences of this new knowledge, in particular, can be discussed in a more general context, such as understanding the role of the present findings in determining the characteristics of the favism pathology as a whole.

The role of SH groups in the regulation of Gardos channels in glucose deficiency

   Background. Disruption of the energy balance of erythrocytes under conditions of a decrease in the glycolysis level can cause a change in the ion permeability of their membrane.   The aim. To study Ca2+-dependent potassium permeability of the erythrocytes membrane in the presence of SH group modifiers under conditions of glucose deficiency.   Materials and methods. The study used precipitated erythrocytes obtained from the blood of 20 male Wistar rats. The change in the Ca2+-dependent potassium conductivity of the erythrocyte membrane was determined using the potentiometric method. The A23187-and redox-induced hyperpolarization responses of erythrocytes were evaluated.   Results. Glucose deficiency in the medium, as well as the use of the glycolysis inhibitor 2-deoxyglucose, led to an increase in the amplitude of A23187-stimulated membrane hyperpolarization by the opening of the Gardos channels. At the same time, the redox-dependent hyperpolarization of the erythrocyte membrane turned out to be insensitive to a decrease in the glucose content in the medium and to the glycolysis inhibition. The effects of SH group modifiers in the normal incubation medium and under glucose deficiency turned out to be multidirectional and depended on the method of stimulation of Gardos channels.   Conclusion. The results obtained indicate that metabolic disorders in erythrocytes under conditions of glucose deficiency lead to a change in the mechanisms of control of Gardos channels with the participation of SH groups of the proteins of these channels or their regulatory proteins.

Comparison of various RBC indices and Glucose 6 phosphate dehydrogenase activity in patients with and without malaria

Introduction and Aim: Malaria is endemic in many parts of India. Glucose 6 phosphate dehydrogenase (G6PD) deficiency is known to protect against malaria. G6PD deficient individuals afflicted with malaria when treated with primaquine, the first line oxidant drug of malaria, encounter adverse to fatal complications due to acute precipitation of hemolytic anemia. There is a need to assess RBC indices in malaria, its implications in G6PD deficiency, and its acute manifestations. The aim of this study was to compare and correlate various RBC indices and G6PD activity in patients with and without malaria and to find a prevalence of G6PD deficiency in a tertiary care hospital.     Materials and Methods: The present study was carried out by the Biochemistry Department of Kasturba Medical College, Manipal in 363 participants (with malaria and without malaria).  Mann Whitney U test and Spearman’s Rank correlation were employed to assess group differences and correlation, respectively.   Results: 218 cases of malaria in 365 days from a tertiary care hospital in South India is an alarming incidence and annuls the fact that the malaria prevalence is relatively low in South India. Complete blood counts and red blood indices did not show any statistically significant difference between the study groups. No statistically significant correlation was found between G6PD activity and RBC indices in the present study.   Conclusion: No significant differences between hematological indicators and malaria with or without G6PD deficiency hint towards the necessity of G6PD tests for radical treatment of malaria as hematological indices are unable to predict the defective enzyme activity.

Mechanisms of 8-aminoquinoline induced haemolytic toxicity in a G6PDd humanized mouse model

Primaquine (PQ) and Tafenoquine (TQ) are clinically important 8‐aminoquinolines (8‐AQ) used for radical cure treatment of P. vivax infection, known to target hepatic hypnozoites. 8‐AQs can trigger haemolytic anaemia in individuals with glucose‐6‐phosphate dehydrogenase deficiency (G6PDd), yet the mechanisms of haemolytic toxicity remain unknown. To address this issue, we used a humanized mouse model known to predict haemolytic toxicity responses in G6PDd human red blood cells (huRBCs). To evaluate the markers of eryptosis, huRBCs were isolated from mice 24–48 h post‐treatment and analysed for effects on phosphatidylserine (PS), intracellular reactive oxygen species (ROS) and autofluorescence. Urinalysis was performed to evaluate the occurrence of intravascular and extravascular haemolysis. Spleen and liver tissue harvested at 24 h and 5–7 days post‐treatment were stained for the presence of CD169+ macrophages, F4/80+ macrophages, Ter119+ mouse RBCs, glycophorin A+ huRBCs and murine reticulocytes (muRetics). G6PDd‐huRBCs from PQ/TQ treated mice showed increased markers for eryptosis as early as 24 h post‐treatment. This coincided with an early rise in levels of muRetics. Urinalysis revealed concurrent intravascular and extravascular haemolysis in response to PQ/TQ. Splenic CD169+ macrophages, present in all groups at day 1 post‐dosing were eliminated by days 5–7 in PQ/TQ treated mice only, while liver F4/80 macrophages and iron deposits increased. Collectively, our data suggest 8‐AQ treated G6PDd‐huRBCs have early physiological responses to treatment, including increased markers for eryptosis indicative of oxidative stress, resulting in extramedullary haematopoiesis and loss of splenic CD169+ macrophages, prompting the liver to act as the primary site of clearance.

Effect of feeding mid- or zero-tannin faba bean cultivars differing in vicine and covicine content on diet nutrient digestibility and growth performance of weaned pigs

To prioritize what cultivars to grow to feed pigs, 5 faba bean cultivars including 3 zero-tannin, high vicine and covicine cultivars (Snowbird, Snowdrop, Tabasco) and 2 medium-tannin, lower vicine and covicine cultivars (Fabelle, and Malik) were fed to compare effects on diet nutrient digestibility and growth performance of weaned pigs. A total of 260 pigs (8 ± 1.2 kg), weaned at 20 ± 1 d of age housed 2 barrows and 2 gilts/pen were fed 1 of 5 dietary regimens starting 1-week post-weaning for 4 weeks in a randomized complete block design. Diets including each cultivar at 20% or 30% provided 10.2 and 10.1 MJ net energy (NE)/kg and 1.3 and 1.2 g standardized ileal digestible (SID) lysine (Lys)/MJ NE in phase 1 and phase 2, respectively. Digestibility data were analyzed using PROC GLIMMIX and growth performance data were analyzed using PROC MIXED with pen as experimental unit. Fabelle contained the most condensed tannins (CT; 0.53%) but the least vicine (0.04%) and covicine (0.01%). Zero-tannin cultivars contained little CT (&lt; 0.2%) but had the greatest vicine (0.5%) and covicine content (0.4%). For phase 1, diet apparent total tract digestibility (ATTD) of dry mater (DM), gross energy (GE), crude protein (CP), digestible energy (DE), and NE values did not differ among cultivars. For phase 2, diet ATTD of DM and GE were greatest (P &lt; 0.05) for Snowdrop and Tabasco, intermediate for Fabelle, and lowest for Malik; Snowbird was not different from Fabelle or Malik. Diet ATTD of CP was greatest (P &lt; 0.05) for Tabasco, intermediate for Snowbird, and lowest for Malik; Snowdrop was not different from Tabasco or Snowbird, and Fabelle was not different from Snowbird or Malik. Diet DE and NE values were greatest (P &lt; 0.05) for Tabasco, intermediate for Fabelle and Snowdrop, and lowest for Snowbird; Malik was not different from Fabelle or Snowbird. For the entire trial (d 0 to 28), daily feed disappearance and weight gain for pigs fed Fabelle were 10% greater (P &lt; 0.05) than those fed Malik; pigs fed zero-tannin cultivar diets were intermediate. Pigs fed Fabelle were 1.6 kg heavier (P &lt; 0.05) than those fed Malik at the end of the trial; pigs fed zero-tannin cultivar diets were intermediate. In conclusion, growth performance of pigs fed faba bean cultivar diets was more related to feed disappearance than diet nutrient digestibility. Vicine and covicine instead of condensed tannin content of faba bean cultivars seemed more relevant to growth performance in weaned pigs.

Enhanced Intracellular Reactive Oxygen Species by Photodynamic Therapy Effectively Promotes Chemoresistant Cell Death

Anti-cancer chemo-drugs can cause a rapid elevation of intracellular reactive oxygen species (ROS) levels. An imbalance in ROS production and elimination systems leads to cancer cell resistance to chemotherapy. This study aimed to evaluate the mechanism and effect of ROS on multidrug resistance in various human chemoresistant cancer cells by detecting the changes in the amount of ROS, the expression of ROS-related and glycolysis-related genes, and cell death. We found that ROS was decreased while oxidative phosphorylation was increased in chemoresistant cells. We verified that the chemoresistance of cancer cells was achieved in two ways. First, chemoresistant cells preferred oxidative phosphorylation instead of anaerobic glycolysis for energy generation, which increased ATPase activity and produced much more ATP to provide energy. Second, ROS-scavenging systems were enhanced in chemoresistant cancer cells, which in turn decreased ROS amount and thus inhibited chemo-induced cell death. Our in vitro and in vivo photodynamic therapy further demonstrated that elevated ROS production efficiently inhibited chemo-drug resistance and promoted chemoresistant cell death. Taken together, targeting ROS systems has a great potential to treat cancer patients with chemoresistance.

Ileal digestibility of energy and amino acids in three faba bean cultivars (Vicia faba L.) planted and harvested early or late in broiler chickens

A concern of both pulse growers and poultry producers is how the timing of planting and harvesting affect the nutritional quality of faba bean for broiler chickens. To investigate, half of the seed of 2 zero-tannin cultivars (Snowbird and Snowdrop) and 1 low vicine and convicine cultivar (Fabelle) were planted at a single site either in early May and harvested in late September (EARLY) or planted in late May and harvested in late October (LATE). Diets of the 3 EARLY or LATE cultivars (95% inclusion) were fed to 756 broiler chickens (Ross 708) from d 15. Chickens were housed in 56 floor pens (13-14 birds/pen) in a 3 × 2 factorial arrangement (7 pens/diet). A nitrogen-free diet to correct for endogenous amino acid (AA) losses was fed to broilers in 14 pens from d 20. Ileal digesta was collected after euthanizing birds on day 23 or 24. Planting and harvesting LATE vs. EARLY increased the proportion of immature beans from 5 to 64% for Snowbird, 7 to 79% for Snowdrop, and 22 to 80% for Fabelle. Planting and harvesting LATE vs. EARLY increased the proportion of frost-damaged beans from 20 to 83% for Snowbird, 36 to 88% for Snowdrop, and 5 to 29% for Fabelle. Planting and harvesting LATE vs. EARLY increased (P < 0.001) apparent ileal digestibility (AID) of gross energy (GE) by 45% and standardized ileal digestibility (SID) of CP by 13%. Planting and harvesting LATE vs. EARLY increased (P < 0.001) SID of AA by 11% except Cys. Snowbird and Snowdrop had greater (P < 0.05) SID of AA by 4.5% except Thr and Trp compared with Fabelle. Fabelle had 13% greater (P < 0.001) SID of Trp compared with Snowbird or Snowdrop. Results indicate that planting and harvesting LATE vs. EARLY increased GE, CP, and AA digestibility possibly by frost interrupting bean ripening on the field. Hull tannin content may have reduced the AA digestibility of Fabelle compared with Snowbird or Snowdrop.

Feeding different cultivars and quality levels of faba bean to broiler chickens

A concern of both pulse growers and poultry producers is how frost damage around harvest time affects the nutritional quality of faba bean for broiler chickens. To investigate, two zero-tannin cultivars (Snowbird, Snowdrop) and one low vicine and convicine cultivar (Fabelle) sourced from seed growers were spring planted 3 weeks later than recommended (mid-May) and harvested late October to purposely increase frost damage. Parent, certified seed (high quality), and harvested frost damaged beans (low quality) of the three cultivars were fed to 740 chickens housed in 64 floor pens in a 2 × 3 factorial plus control (9 pens of 11 or 12 birds per treatment). Starter (d 0 to 11), grower (d 12 to 24), and finisher (d 25 to 40) diets included 15%, 30%, and 45% faba bean in partial (starter, grower) or total replacement of soybean meal (SBM; control). Harvested Snowbird, Snowdrop, Fabelle averaged 52%, 62%, 17% blackened hull and 35%, 43%, 51% immature beans, respectively. There was a cultivar × quality interaction (P < 0.05) on daily feed disappearance (ADFI) and gain-to-feed (G:F). Broilers fed low-quality Snowdrop consumed 10 g/d more finisher and 6 g/d more feed overall than those fed low-quality Snowbird or Fabelle; broilers fed parent seed were intermediate. Feeding low-quality Fabelle resulted in best overall G:F (0.646) versus high-quality Snowbird (0.611), high-quality Fabelle (0.624), or low-quality Snowdrop (0.624). Average daily weight gain (ADG) and bird body weight (BW) at the end of each growth phase were not affected by cultivar or quality level. Controls fed SBM only grew 2.75 g/d faster overall and were 113.5 g heavier at the end of the trial than broilers fed faba bean (P < 0.05). Controls fed SBM only had 0.024 g/g better overall G:F than broilers fed faba bean (P < 0.05). Feeding low-quality beans or high-quality seed had no effect on antemortem BW, chilled carcass weight (WT), dressing percentage or yield of saleable cuts except that broilers fed Snowbird or Snowdrop had 0.8%-unit larger thighs than those fed Fabelle. Controls fed SBM only were 110 g heavier at slaughter, had 72 g heavier chilled carcass WT, and 0.5%-unit greater dressing percentage than broilers fed faba bean (P < 0.05). These results indicate that feeding frost damaged and(or) immature faba bean, to the extent observed in this trial, did not negatively affect growth performance or carcass attributes of broiler chickens compared to feeding parent, certified, high-quality seed of these cultivars.

Erythrocytes: Central Actors in Multiple Scenes of Atherosclerosis

The development and progression of atherosclerosis (ATH) involves lipid accumulation, oxidative stress and both vascular and blood cell dysfunction. Erythrocytes, the main circulating cells in the body, exert determinant roles in the gas transport between tissues. Erythrocytes have long been considered as simple bystanders in cardiovascular diseases, including ATH. This review highlights recent knowledge concerning the role of erythrocytes being more than just passive gas carriers, as potent contributors to atherosclerotic plaque progression. Erythrocyte physiology and ATH pathology is first described. Then, a specific chapter delineates the numerous links between erythrocytes and atherogenesis. In particular, we discuss the impact of extravasated erythrocytes in plaque iron homeostasis with potential pathological consequences. Hyperglycaemia is recognised as a significant aggravating contributor to the development of ATH. Then, a special focus is made on glycoxidative modifications of erythrocytes and their role in ATH. This chapter includes recent data proposing glycoxidised erythrocytes as putative contributors to enhanced atherothrombosis in diabetic patients.

Donor sex, age and ethnicity impact stored red blood cell antioxidant metabolism through mechanisms in part explained by glucose 6-phosphate dehydrogenase levels and activity

Red blood cell storage in the blood bank promotes the progressive accumulation of metabolic alterations that may ultimately impact the erythrocyte capacity to cope with oxidant stressors. However, the metabolic underpinnings of the capacity of RBCs to resist oxidant stress and the potential impact of donor biology on this phenotype are not known. Within the framework of the REDS-III RBC-Omics study, RBCs from 8,502 healthy blood donors were stored for 42 days and tested for their propensity to hemolyze following oxidant stress. A subset of extreme hemolyzers donated a second unit of blood, which was stored for 10, 23, and 42 days and profiled again for oxidative hemolysis and metabolomics (599 samples). Alterations of RBC energy and redox homeostasis were noted in donors with high oxidative hemolysis. RBCs from females, donors over 60 years old, donors of Asian/South Asian race-ethnicity, and RBCs stored in additive solution-3 were each independently characterized by improved antioxidant metabolism compared to, respectively, males, donors under 30 years old, Hispanic and African American race ethnicity donors, and RBCs stored in additive solution-1. Merging metabolomics data with results from an independent GWAS study on the same cohort, we identified metabolic markers of hemolysis and G6PD-deficiency, which were associated with extremes in oxidative hemolysis and dysregulation in NADPH and glutathione-dependent detoxification pathways of oxidized lipids. Donor sex, age, ethnicity, additive solution and G6PD status impact the metabolism of the stored erythrocyte and its susceptibility to hemolysis following oxidative insults.

The Redox Balance and Membrane Shedding in RBC Production, Maturation, and Senescence

Membrane shedding in the form of extracellular vesicles plays a key role in normal physiology and pathology. Partial disturbance of the membrane-cytoskeleton linkage and increased in the intracellular Ca content are considered to be mechanisms underlying the process, but it is questionable whether they constitute the primary initiating steps. Homeostasis of the redox system, which depends on the equilibrium between oxidants and antioxidants, is crucial for many cellular processes. Excess oxidative power results in oxidative stress, which affects many cellular components, including the membrane. Accumulating evidence suggests that oxidative stress indirectly affects membrane shedding most probably by affecting the membrane-cytoskeleton and the Ca content. In red blood cells (RBCs), changes in both the redox system and membrane shedding occur throughout their life-from birth-their production in the bone marrow, to death-aging in the peripheral blood and removal by macrophages in sites of the reticuloendothelial system. Both oxidative stress and membrane shedding are disturbed in diseases affecting the RBC, such as the hereditary and acquired hemolytic anemias (i.e., thalassemia, sickle cell anemia, and autoimmune hemolytic anemia). Herein, I review some data-based and hypothetical possibilities that await experimental confirmation regarding some aspects of the interaction between the redox system and membrane shedding and its role in the normal physiology and pathology of RBCs.

In Vivo Imaging with Genetically Encoded Redox Biosensors

Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.

Syk Kinase Inhibitors Synergize with Artemisinins by Enhancing Oxidative Stress in Plasmodium falciparum-Parasitized Erythrocytes

Although artemisinin-based combination therapies (ACTs) treat Plasmodium falciparum malaria effectively throughout most of the world, the recent expansion of ACT-resistant strains in some countries of the Greater Mekong Subregion (GMS) further increased the interest in improving the effectiveness of treatment and counteracting resistance. Recognizing that (1) partially denatured hemoglobin containing reactive iron (hemichromes) is generated in parasitized red blood cells (pRBC) by oxidative stress, (2) redox-active hemichromes have the potential to enhance oxidative stress triggered by the parasite and the activation of artemisinin to its pharmaceutically active form, and (3) Syk kinase inhibitors block the release of membrane microparticles containing hemichromes, we hypothesized that increasing hemichrome content in parasitized erythrocytes through the inhibition of Syk kinase might trigger a virtuous cycle involving the activation of artemisinin, the enhancement of oxidative stress elicited by activated artemisinin, and a further increase in hemichrome production. We demonstrate here that artemisinin indeed augments oxidative stress within parasitized RBCs and that Syk kinase inhibitors further increase iron-dependent oxidative stress, synergizing with artemisinin in killing the parasite. We then demonstrate that Syk kinase inhibitors achieve this oxidative enhancement by preventing parasite-induced release of erythrocyte-derived microparticles containing redox-active hemichromes. We also observe that Syk kinase inhibitors do not promote oxidative toxicity to healthy RBCs as they do not produce appreciable amounts of hemichromes. Since some Syk kinase inhibitors can be taken daily with minimal side effects, we propose that Syk kinase inhibitors could evidently contribute to the potentiation of ACTs.

Genotyping by Sequencing Reads of 20 Vicia faba Lines with High and Low Vicine and Convicine Content

The grain faba bean (Vicia faba) which belongs to the family of the Leguminosae, is a crop that is grown worldwide for consumption by humans and livestock. Despite being a rich source of plant-based protein and various agro-ecological advantages its usage is limited due to its anti-nutrients in the form of the seed-compounds vicine and convicine (V+C). While markers for a low V+C content exist the underlying pathway and the responsible genes have remained unknown for a long time and only recently a possible pathway and enzyme were found. Genetic research into Vicia faba is difficult due to the lack of a reference genome and the near exclusivity of V+C to the species. Here, we present sequence reads obtained through genotyping-by-sequencing of 20 Vicia faba lines with varying V+C contents. For each line, ∼3 million 150 bp paired end reads are available. This data can be useful in the genomic research of Vicia faba in general and its V+C content in particular.

Identification of Regulatory SNPs Associated with Vicine and Convicine Content of Vicia faba Based on Genotyping by Sequencing Data Using Deep Learning

Faba bean (Vicia faba) is a grain legume, which is globally grown for both human consumption as well as feed for livestock. Despite its agro-ecological importance the usage of Vicia faba is severely hampered by its anti-nutritive seed-compounds vicine and convicine (V+C). The genes responsible for a low V+C content have not yet been identified. In this study, we aim to computationally identify regulatory SNPs (rSNPs), i.e., SNPs in promoter regions of genes that are deemed to govern the V+C content of Vicia faba. For this purpose we first trained a deep learning model with the gene annotations of seven related species of the Leguminosae family. Applying our model, we predicted putative promoters in a partial genome of Vicia faba that we assembled from genotyping-by-sequencing (GBS) data. Exploiting the synteny between Medicago truncatula and Vicia faba, we identified two rSNPs which are statistically significantly associated with V+C content. In particular, the allele substitutions regarding these rSNPs result in dramatic changes of the binding sites of the transcription factors (TFs) MYB4, MYB61, and SQUA. The knowledge about TFs and their rSNPs may enhance our understanding of the regulatory programs controlling V+C content of Vicia faba and could provide new hypotheses for future breeding programs.

A Translational In Vivo and In Vitro Metabolomic Study Reveals Altered Metabolic Pathways in Red Blood Cells of Type 2 Diabetes

Clinical parameters used in type 2 diabetes mellitus (T2D) diagnosis and monitoring such as glycosylated haemoglobin (HbA1c) are often unable to capture important information related to diabetic control and chronic complications. In order to search for additional biomarkers, we performed a pilot study comparing T2D patients with healthy controls matched by age, gender, and weight. By using ¹H-nuclear magnetic resonance (NMR) based metabolomics profiling of red blood cells (RBCs), we found that the metabolic signature of RBCs in T2D subjects differed significantly from non-diabetic controls. Affected metabolites included glutathione, 2,3-bisphophoglycerate, inosinic acid, lactate, 6-phosphogluconate, creatine and adenosine triphosphate (ATP) and several amino acids such as leucine, glycine, alanine, lysine, aspartate, phenylalanine and tyrosine. These results were validated by an independent cohort of T2D and control patients. An analysis of the pathways in which these metabolites were involved showed that energetic and redox metabolism in RBCs were altered in T2D, as well as metabolites transported by RBCs. Taken together, our results revealed that the metabolic profile of RBCs can discriminate healthy controls from T2D patients. Further research is needed to determine whether metabolic fingerprint in RBC could be useful to complement the information obtained from HbA1c and glycemic variability as well as its potential role in the diabetes management.

Hemolytic Dynamics of Weekly Primaquine Antirelapse Therapy Among Cambodians With Acute Plasmodium vivax Malaria With or Without Glucose-6-Phosphate Dehydrogenase Deficiency

Background

Hemoglobin (Hb) data are limited in Southeast Asian glucose-6-phosphate dehydrogenase (G6PD) deficient (G6PD⁻) patients treated weekly with the World Health Organization–recommended primaquine regimen (ie, 0.75 mg/kg/week for 8 weeks [PQ _0.75]).

Methods

We treated Cambodians who had acute Plasmodium vivax infection with PQ_0.75 and a 3-day course of dihydroartemisinin/piperaquine and determined the Hb level, reticulocyte count, G6PD genotype, and Hb type.

Results

Seventy-five patients (male sex, 63) aged 5–63 years (median, 24 years) were enrolled. Eighteen were G6PD deficient (including 17 with G6PD Viangchan) and 57 were not G6PD deficient; 26 had HbE (of whom 25 were heterozygous), and 6 had α-/β-thalassemia. Mean Hb concentrations at baseline (ie, day 0) were similar between G6PD deficient and G6PD normal patients (12.9 g/dL [range, 9‒16.3 g/dL] and 13.26 g/dL [range, 9.6‒16 g/dL], respectively; P = .46). G6PD deficiency (P = <.001), higher Hb concentration at baseline (P = <.001), higher parasitemia level at baseline (P = .02), and thalassemia (P = .027) influenced the initial decrease in Hb level, calculated as the nadir level minus the baseline level (range, −5.8–0 g/dL; mean, −1.88 g/dL). By day 14, the mean difference from the day 7 level (calculated as the day 14 level minus the day 7 level) was 0.03 g/dL (range, −0.25‒0.32 g/dL). Reticulocyte counts decreased from days 1 to 3, peaking on day 7 (in the G6PD normal group) and day 14 (in the G6PD deficient group); reticulocytemia at baseline (P = .001), G6PD deficiency (P = <.001), and female sex (P = .034) correlated with higher counts. One symptomatic, G6PD-deficient, anemic male patient was transfused on day 4.

Conclusions

The first PQ_0.75 exposure was associated with the greatest decrease in Hb level and 1 blood transfusion, followed by clinically insignificant decreases in Hb levels. PQ_0.75 requires monitoring during the week after treatment. Safer antirelapse regimens are needed in Southeast Asia.

Clinical Trials Registration

ACTRN12613000003774.

Decoding the metabolic landscape of pathophysiological stress-induced cell death in anucleate red blood cells

BACKGROUND

In response to stress, anucleate red blood cells (RBCs) can undergo a process of atypical cell death characterised by intracellular Ca²⁺ accumulation and phosphatidylserine (PS) externalisation. Here we studied alterations in RBC metabolism, a critical contributor to their capacity to survive environmental challenges, during this process.

MATERIALS AND METHODS

Metabolomics analyses of RBCs and supernatants, using ultra-high-pressure liquid chromatography coupled to mass spectrometry, were performed after in vitro exposure of RBCs to different pathophysiological cell stressors, including starvation, extracellular hypertonicity, hyperthermia, and supraphysiological ionic stress. Cell death was examined by flow cytometry.

RESULTS

Our data show that artificially enhancing RBC cytosolic Ca²⁺ influx significantly enhanced purine oxidation and strongly affected cellular bioenergetics by reducing glycolysis. Depleting extracellular Ca²⁺ curtailed starvation-induced cell death, an effect paralleled by the activation of compensatory pathways such as the pentose phosphate pathway, carboxylic acid metabolism, increased pyruvate to lactate ratios (methemoglobin reductase activation), one-carbon metabolism (protein-damage repair) and glutathione synthesis; RBCs exposed to hypertonic shock displayed a similar metabolic profile. Furthermore, cell stress promoted lipid remodelling as reflected by the levels of free fatty acids, acyl-carnitines and CoA precursors. Notably, RBC PS exposure, independently of the stressor, showed significant correlation with the levels of free fatty acids, glutamate, cystine, spermidine, tryptophan, 5-oxoproline, lactate, and hypoxanthine.

DISCUSSION

In conclusion, different cell death-inducing pathophysiological stressors, encountered in various clinical conditions, result in differential RBC metabolic phenotypes, only partly explained by intracellular Ca²⁺ levels and ATP availability.

Ex Vivo Study of Laban's Role in Decreasing Hemolysis Crisis in G6PD-Deficient Patients

In spite of the vast nutritional and environmental benefits provided by fava bean (Vicia faba), the ingestion of vicine/convicine provokes an acute hemolytic anemia called favism in individuals with a glucose-6-phosphate dehydrogenase (G6PD) deficiency. The elimination of these glycosides is a goal that could be accomplished using different processing methods including bacteriological treatment. Laban as a good source of lactic acid bacteria was tested in an ex vivo assay on human blood samples in order to determine its capacity in decreasing the hemolysis crisis induced by the ingestion of fava beans. Results indicate a significant decrease in human blood cell hemolysis after the treatment of fava beans by Laban. This decrease in hemolysis was also correlated with the G6PD deficiency categorization. The highest hemolysis level (mean: 23.11 ± 0.76%) was observed in samples with G6PD activity between 10 and 30%, while the lowest hemolysis level (mean: 5.75 ± 0.64%) was observed in samples with G6PD activity more than 60%. This decrease was correlated with a high antioxidant capacity of Laban (51.61 ± 1.13% expressed by the percentage inhibition of DPPH radical). The counts of isolates from MRS and M17 culture plates were 6.75 ± 0.095 and 7.91 ± 0.061 log cfu ml^-1, respectively. In conclusion, the synergy between the antioxidant properties of Laban and the possible decrease of vicine and convicine concentrations by lactobacillus found in the fermented dairy products could explain the ability of Laban to reduce the hemolysis crisis ex vivo.

Signaling Response to Transient Redox Stress in Human Isolated T Cells: Molecular Sensor Role of Syk Kinase and Functional Involvement of IL2 Receptor and L-Selectine

Reactive oxygen species (ROS) are central effectors of inflammation and play a key role in cell signaling. Previous reports have described an association between oxidative events and the modulation of innate immunity. However, the role of redox signaling in adaptive immunity is still not well understood. This work is based on a novel investigation of diamide, a specific oxidant of sulfhydryl groups, and it is the first performed in purified T cell tyrosine phosphorylation signaling. Our data show that ex vivo T cells respond to –SH group oxidation with a distinctive tyrosine phosphorylation response and that these events elicit specific cellular responses. The expression of two essential T-cell receptors, CD25 and CD62L, and T-cell cytokine release is also affected in a specific way. Experiments with Syk inhibitors indicate a major contribution of this kinase in these phenomena. This pilot work confirms the presence of crosstalk between oxidation of cysteine residues and tyrosine phosphorylation changes, resulting in a series of functional events in freshly isolated T cells. Our experiments show a novel role of Syk inhibitors in applying their anti-inflammatory action through the inhibition of a ROS-generated reaction.

Evaluation of quantitative biosensor for glucose-6-phosphate dehydrogenase activity detection

Neonatal jaundice is a common and severe disease in premature infants with Glucose-6-Phosphate Dehydrogenase (G-6-PD) deficiency. The World Health Organization (WHO) has recommended screening for G-6-PD deficiency in newborns for early recognition as well as to prevent unwanted outcomes in a timely manner. The present study aimed to assess a point-of-care, careSTARTTM G6PD biosensor as a quantitative method for the diagnosis of G-6-PD deficiency. Factors influencing the evaluation of G-6-PD enzyme activity were examined in 40 adults, including ethylenediaminetetraacetic acid (EDTA) anticoagulant, hematocrit concentration, storage temperature and time. Analytic performance of the careSTARTTM G6PD biosensor was evaluated in 216 newborns and compared with fluorescent spot test (FST) and standard quantitative G-6-PD enzyme activity (SGT) assay. The results of factors affecting the G-6-PD enzyme activity showed that the activity determined from finger-prick was not statistically different from venous blood (p = 0.152). The G-6-PD value was highly dependent on the hematocrit and rose with increasing hematocrit concentration. Its activity was stable at 4°C for 3 days. Reliability analysis between the careSTARTTM G6PD biosensor and SGT assay showed a strong correlation with a Pearson's correlation coefficient of 0.82 and perfect agreement by intraclass correlation coefficient (ICC) of 0.90. Analysis of the area under the Receiver Operating Curve (AUC) illustrated that the careSTARTTM G6PD biosensor had 100% sensitivity, 96% specificity, 73% positive predictive value (PPV), 100% negative predictive value (NPV) and 97% accuracy at 30% of residual activity. While the diagnostic ability for identifying G-6-PD deficiency had 78% sensitivity, 89% specificity, 56% positive predictive value (PPV), 96% negative predictive value (NPV) and 88% accuracy when stratified by gender. The careSTARTTM G6PD biosensor is an attractive option as a point-of-care quantitative method for G-6-PD activity detection. Quantification of G-6-PD enzyme activity in newborns is the most effective approach for the management of G-6-PD deficiency to prevent severe jaundice and acute hemolysis.

Hematological, biochemical and antioxidant indices variations in regular blood donors among Mediterranean regions

BACKGROUND & OBJECTIVES

One of the most important problems in Mediterranean regions is finding blood donors to overcome the high need of its population. Understanding the health benefits of blood donation frequency will activate more volunteers to donate. The aim of this study variations of hematological and biochemical indices in regular male and female donors from Greece and Italy METHODS: A cross-sectional study consisted of 350 voluntary blood donors (VDs)was conducted in two mediterranean Blood Banks, Greece and Italy. The first one from the General Hospital of Naousa, Greece on samples of 90 regular and 60 first-time blood donors. The second one from AOU Sassari, Sardinia, Italy on convenient samples of 100 first-time samples and 100 regular blood donors. Donors' particulars were obtained from blood bank records. The hematological and biochemical parameters were determined for all donors and Total Antioxidant Status (TAS) only for greek VDs.

RESULTS

High frequency blood donation of Greek VDs could be associated with evidence of reduction of body iron stores, reduced oxidative stress and improvement of liver function biomarkers in regular groups. Interestingly, Sardinian regular male VDs presented increased iron stores in compare with the first time VDs. In both Mediterranean populations (Greeks and Italians) the lipid profile of the female regular blood donors has been improved in compare with the first timers.

CONCLUSION

Regular blood donation increases antioxidant capacity and affects positively the hematological parameters and biochemical biomarkers in donors. Gender plays an important role in relation to all hematological and biochemical parameters. Further studies in larger population should evaluate the beneficial-effect of blood donation and promote people to donate more frequent.

The tolerability of single low dose primaquine in glucose-6-phosphate deficient and normal falciparum-infected Cambodians

Background

The WHO recommends single low-dose primaquine (SLDPQ, 0.25 mg/kg body weight) in falciparum-infected patients to block malaria transmission and contribute to eliminating multidrug resistant Plasmodium falciparum from the Greater Mekong Sub region (GMS). However, the anxiety regarding PQ-induced acute haemolytic anaemia in glucose-6-phosphate dehydrogenase deficiency (G6PDd) has hindered its use. Therefore, we assessed the tolerability of SLDPQ in Cambodia to inform national policy.

Methods

This open randomised trial of dihydroartemisinin-piperaquine (DHAPP) + SLDPQ vs. DHAPP alone recruited Cambodians aged ≥1 year with acute uncomplicated P. falciparum. Randomisation was 4:1 DHAPP+SLDPQ: DHAPP for G6PDd patients and 1:1 for G6PDn patients, according to the results of the qualitative fluorescent spot test. Definitive G6PD status was determined by genotyping. Day (D) 7 haemoglobin (Hb) concentration was the primary outcome measure.

Results

One hundred nine patients (88 males, 21 females), aged 4–76 years (median 23) were enrolled; 12 were G6PDd Viangchan (9 hemizygous males, 3 heterozygous females). Mean nadir Hb occurred on D7 [11.6 (range 6.4 ─ 15.6) g/dL] and was significantly lower (p = 0.040) in G6PDd (n = 9) vs. G6PDn (n = 46) DHAPP+SLDPQ recipients: 10.9 vs. 12.05 g/dL, Δ = -1.15 (95% CI: -2.24 ─ -0.05) g/dL. Three G6PDn patients had D7 Hb concentrations < 8 g/dL; D7-D0 Hbs were 6.4 ─ 6.9, 7.4 ─ 7.4, and 7.5 ─ 8.2 g/dL.

For all patients, mean (range) D7-D0 Hb decline was -1.45 (-4.8 ─ 2.4) g/dL, associated significantly with higher D0 Hb, higher D0 parasitaemia, and receiving DHAPP; G6PDd was not a factor. No patient required a blood transfusion.

Conclusions

DHAPP+SLDPQ was associated with modest Hb declines in G6PD Viangchan, a moderately severe variant. Our data augment growing evidence that SLDPQ in SE Asia is well tolerated and appears safe in G6PDd patients. Cambodia is now deploying SLDPQ and this should encourage other GMS countries to follow suit.

Trial registration

The clinicaltrials.gov reference number is NCT02434952.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3862-1) contains supplementary material, which is available to authorized users.

Hemolytic jaundice induced by pharmacological dose ascorbic acid in glucose-6-phosphate dehydrogenase deficiency: A case report

RATIONALE

Hemolysis induced by high dose ascorbic acid (AA) in patients with G6PD deficiency has been reported, but is rare. To our knowledge, this is the first reported case of a male with G6PD deficiency, coexpressed with cholecystolithiasis and cholecystitis, who developed extreme hemolysis and hyperbilirubinemia after receiving pharmacological doses ascorbic acid infusion.

PATIENT CONCERNS

A 27-year-old man history with glucose-6-phosphate dehydrogenase deficiency was admitted to our hospital because of cholecystolithiasis and cholecystitis. He appeared with scleral jaundice and very deep colored urine after receiving pharmacological doses ascorbic acid infusion.

DIAGNOSES

Clinical findings when combined with his medical history and various laboratory results confirmed the diagnosis as hemolysis and hyperbilirubinemia induced by ascorbic acid.

INTERVENTIONS

The patient was treated with steroids, hepatoprotective drugs, and folic acid in addition avoidance of agents with known hemolysis risk (such as vitamin C).

OUTCOMES

As a result, the patient's symptoms from hemolytic jaundice improved, hemoglobin remained stable, and the patient was discharged 11 days later.

LESSONS

Clinicians should bear in mind the possibility that vitamin C exposure may result in hemolysis in patients with G6PD deficiency, especially in those with known severe disease.

Membrane protein carbonylation of Plasmodium falciparum infected erythrocytes under conditions of sickle cell trait and G6PD deficiency

Deficiency of glucose-6-phosphate dehydrogenase (G6PD) and sickle cell trait (SCT) are described as the polymorphic disorders prevalent in erythrocytes. Both are considered the result of the selective pressure exerted by Plasmodium parasites over human genome, due to a certain degree of resistance to the clinical symptoms of severe malaria. There exist in both a prooxidant environment that favors the oxidative damage on membrane proteins, which probably is part of molecular protector mechanisms. Nevertheless, mechanisms are not completely understood at molecular level for each polymorphism yet, and even less if are commons for several of them. Here, synchronous cultures at high parasitemia levels of P. falciparum 3D7 were used to quantify oxidative damage in membrane proteins of erythrocytes with G6PD deficient and SCT. Carbonyl index by dot blot assay was used to calculate the variation of oxidative damage during the asexual phases. Besides, protein carbonylation profiles were obtained by Western blot and complemented with mass spectrometry using MALDI-TOF-TOF analysis. Erythrocytes with G6PD deficient and SCT showed higher carbonyl index values than control and similar profiles of carbonylated proteins; moreover, cytoskeletal and stress response proteins were identified as the main targets of oxidative damage. Therefore, both polymorphisms promote carbonylation on the same membrane proteins. Finally, these results allowed to reinforce the hypothesis of oxidative damage in erythrocyte membrane proteins as molecular mechanism of human adaptation to malaria infection.

A practical toxicity bioassay for vicine and convicine levels in faba bean (Vicia faba)

BACKGROUND

Faba bean (Vicia faba) vicine and convicine (V-C) aglycones (divicine and isouramil respectively) provoke an acute hemolytic anemia called favism in individuals with a glucose-6-phosphate dehydrogenase (G6PD) enzyme defect in their red blood cells. Geneticists/plant breeders are working with faba bean to decrease V-C levels to improve public acceptance of this high-protein pulse crop. Here, we present a fast and simple ex vivo in vitro bioassay for V-C toxicity testing of faba bean or faba bean food products.

RESULTS

We have shown that 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU)-treated (i.e., sensitized) normal red blood cells, like G6PD-defective blood, displayed (i) continuous glutathione (GSH) depletion with no regeneration as incubation time and the dose of aglycones increased, (ii) progressive accumulation of denatured hemoglobin products into high molecular weight (HMW) proteins with increased aglycone dose, (iii) both band 3 membrane proteins and hemichromes, in HMW protein aggregates. We have also demonstrated that sensitized red blood cells can effectively differentiate various levels of toxicity among faba bean varieties through the two hemolysis biomarkers: GSH depletion and HMW clumping.

CONCLUSION

BCNU-sensitized red blood cells provide an ideal model for favism blood, to assess and compare the toxicity of faba bean varieties and their food products. © 2018 Society of Chemical Industry.

Evaluating of β-carotene role in ameliorating of favism-induced disturbances in blood and testis

Background

Favism is an acute hemolytic anemia occurs in glucose 6-phosphate dehydrogenase (G6-PD) deficient individuals. β-Carotene occurs in vegetables such as carrots. This study aimed to establish the therapeutic effect of β-carotene to rebalance the testicular and blood proteins disturbances in favism.

Methods

Forty-eight male rats were divided into six equal groups; Groups 1, 2 and 3: normal rats were daily oral administrated with 1 ml saline, 1 ml corn oil and β-carotene (60 mg/kg dissolved in 1 ml corn oil), respectively, once a day over 15 days period. Group 4 (favism-induced group): normal rats injected intraperitoneal (ip) with diethyl maleate (5 μl/rat) and after 1 h injected ip with 1/3 LD50 of faba beans ethanolic extract for 15 day to induce favism. Groups 5 and 6: favism-induced rats were daily oral administered with 30 and 60 mg/kg β-carotene dissolved in 1 ml corn oil, respectively, once a day over 15 days.

Results

The results revealed that oral administration of corn oil or β-carotene into normal rats over 15 days period did not induce any change. In favism-induced groups, hematological parameters, liver function, serum glucose, G6-PD, luteinizing and follicle-stimulating hormones and sex-hormone binding globulin showed significant increase. Moreover, serum testosterone and dehydroepiandrosterone sulfate, testicular G6-PD, 3β-hydroxy steroid dehydrogenase, cholesterol and total protein were decreased. Treatment with both doses of β-carotene into favism groups restored all the abovementioned parameters to approach normal values. Favism inhibited blood proteins while β-carotene treatment into favism group stopped blood cells damage and blood proteins inhibition. These results were supported by histological studies.

Conclusions

In conclusion, taken β-carotene into favism group abolished testicular and blood proteins disturbances and this effect was dose dependent.

Metagenomics of pigmented and cholesterol gallstones: the putative role of bacteria

There is growing evidence for bacteria playing a role in the pathogenesis and formation of pigmented gallstones from humans. These studies mainly involved cultivation of gallstone-associated bacteria and 16S rRNA profiling, providing an indirect link between processes involved in gallstone formation by the bacteria in-situ. Here, we provide functional metagenomic evidence of a range of genes involved in bile stress response, biofilm formation, and anaerobic energy metabolism by Gram-negative Klebsiella in pigmented gallstones from a 76-year-old male patient. Klebsiella was also present in one cholesterol-type stone in a 30-year-old female patient who had additional cholesterol gallstones characterised by Gram-positive bacteria. Pigmented stones further revealed a predominance of genes involved in carbohydrate metabolism, whilst cholesterol stones indicated a profile dominanted by protein metabolism possibly reflecting known chemical differences between Gram-negative and Gram-positive biofilm matrices. Archaeal genes were not detected. Complementary carbon and hydrogen isotopic analyses of cholesterol within the patients’ stones revealed homogeneity, suggesting a common diet or cholesterol biosynthesis pathway that has little influence on microbial composition. This pilot study provides a framework to study microbial processes that play a potential role in gallstone formation across markedly different types of stones and patient backgrounds.