Synchrony of G6PD activity and RBC fragility under oxidative stress exerted at normal and G6PD deficiency

Abstract Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in red blood cells (RBC). G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine, which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration.Methods RBC models were developed to analyse the effect of oxidant on RBC oxidative markers namely total glutathione (GSH)and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from twoG6PD heterozygous women with different G6PD activities were also analysed for comparison.Results There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, the CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). The ex vivo models however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model, but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PDViangchan variant with 2.97U/gHb (33% activity) and 6.58 U/gHb (74% activity). Conclusions The GSH analysis has pointed to the 60% G6PD activity cut-off and this data is supportive of the old World Health Organization threshold for intermediate upper limit of 60% G6PD activity. However, there are significant limitations in using MDA assay with CuCl RBC model because the RBC was already stressed due to the copper treatment and thus present a different result when compared to the ex-vivo model.

Download Full-text

G6PD deficiency is associated with renal impairment in T2DM

10.21203/rs.3.rs-36539/v1 ◽

2020 ◽

Author(s):

Nabin Bahadur Basnet ◽

Santosh Pradhan ◽

Rishi Kumar Kafle ◽

Keyoor Gautam

Keyword(s):

Oxidative Stress ◽

High Risk ◽

Renal Impairment ◽

Diabetic Patient ◽

G6pd Deficiency ◽

G6pd Activity ◽

Diabetic Patients ◽

Healthy Control ◽

Disease Study ◽

Severe Degree

Abstract Background Diabetes and its complications including renal impairment are the consequences of increased oxidative stress. Glucose-6-phosphate dehydrogenase (G6PD) is responsible for protection from harmful oxidative metabolites. G6PD deficiency hence leaves these individuals at high risk of oxidative stress and at high risk of diabetes and its complications including renal impairment. If any association between G6PD deficiency and damage to kidney exists in diabetic population then screening for G6PD deficiency in this population will help identify the susceptible patient who may be at higher risk of diabetic complications due to G6PD deficiency and can prevent them with early interventions to help decrease patients’ morbidity in the long run. Methods Healthy control volunteers and diabetic with or without renal impairment were selected after counseling. Body Mass Index and blood pressure were recorded. Blood tests to measure the G6PD activity in fresh whole blood, hemoglobin, glycated hemoglobin, uric acid, and creatinine were done. Urine was tested for the presence of proteinuria. The activity of G6PD was measured. Glomerular filtration rate (eGFR) was estimated with the Modification of Diet in Renal Disease Study (MDRD) Equation. Calculations and statistical analysis were done with open software LibreOffice 6.3.3 and SPSS version 22.0.Results The mean G6PD level of healthy control was 84.27 ± 9 and that of diabetic patient without renal impairment and diabetic patients with renal impairment were 65.05 ± 5.35 and 46.64 ± 6.56 respectively. There was only one participant (4.55%) with G6PD deficiency among healthy controls whereas the proportion of participants having normal, mild to moderate, and severe degree of G6PD deficiency were 77.27%, 13.64%, and 9.09%, respectively for diabetic patient without renal impairment while 40.91%, 22.73%, and 36.36% for those with renal impairment. The proportion of participants with renal impairment had more severe degree of G6PD deficiencies than those without renal impairment (p=0.03).Conclusion The prevalence of G6PD deficiency was higher in diabetics with renal impairment than those with diabetes alone suggesting the relation between G6PD activity and diabetes with renal impairment.

Download Full-text

Determining a Critical Threshold for G6PD Activity below which RBC Response to Oxidative Stress is Poor

10.21203/rs.2.19598/v2 ◽

2020 ◽

Author(s):

Maria Swastika ◽

Alida R Harahap ◽

Lydia V Panggalo ◽

Sri Widia A Jusman ◽

Ari W Satyagraha

Keyword(s):

Oxidative Stress ◽

G6pd Deficiency ◽

Ex Vivo ◽

Strong Association ◽

G6pd Activity ◽

Critical Threshold ◽

Main Function ◽

Ex Vivo Model ◽

Comparison Results ◽

Significant Difference

Abstract Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in RBC. G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration. Methods: RBC models were developed to analyze the effect of oxidant on RBC oxidative markers namely total glutathione (GSH) and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from two G6PD heterozygous women with different G6PD activities were also analyzed for comparison. Results: There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, our CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). Our ex vivo model however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PD Viangchan variant with 2.97 U/gHb (33% activity) and 6.58 U/gHb (74% activity). Conclusions: The GSH analysis has pointed to the 60% G6PD activity cut-off and this data is supportive of the old WHO threshold for intermediate upper limit of 60% G6PD activity. However, there are significant limitations in using MDA assay with CuCl RBC model because the RBC was already stressed due to the copper treatment and thus present a different result when compared to the ex-vivo model.

Download Full-text

THE INFLUENCE OF HAEMOGLOBIN-S AND G6PD DEFICIENCY ON THE ACTIVITY OF THE 17β-HYDROXYSTEROID DEHYDROGENASE OF INTACT HUMAN ERYTHROCYTES

Acta Endocrinologica ◽

10.1530/acta.0.0750793 ◽

1974 ◽

Vol 75 (4) ◽

pp. 793-800

Author(s):

A. O. Sogbesan ◽

O. A. Dada ◽

B. Kwaku Adadevoh

Keyword(s):

Enzyme Activity ◽

Dehydrogenase Activity ◽

Sex Steroids ◽

G6pd Deficiency ◽

Incubation Medium ◽

Hydroxysteroid Dehydrogenase ◽

G6pd Activity ◽

Reverse Transformation ◽

Oxidative Transformation ◽

Haemoglobin S

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.

Download Full-text

TIGAR regulates glycolysis in ischemic kidney proximal tubules

AJP Renal Physiology ◽

10.1152/ajprenal.00459.2014 ◽

2015 ◽

Vol 308 (4) ◽

pp. F298-F308 ◽

Cited By ~ 25

Author(s):

Jinu Kim ◽

Kishor Devalaraja-Narashimha ◽

Babu J. Padanilam

Keyword(s):

Oxidative Stress ◽

Reperfusion Injury ◽

Pentose Phosphate Pathway ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Pentose Phosphate ◽

Atp Depletion ◽

G6pd Activity ◽

Histological Damage ◽

Severe Ischemia

Tp53-induced glycolysis and apoptosis regulator (TIGAR) activation blocks glycolytic ATP synthesis by inhibiting phosphofructokinase-1 activity. Our data indicate that TIGAR is selectively induced and activated in renal outermedullary proximal straight tubules (PSTs) after ischemia-reperfusion injury in a p53-dependent manner. Under severe ischemic conditions, TIGAR expression persisted through 48 h postinjury and induced loss of renal function and histological damage. Furthermore, TIGAR upregulation inhibited phosphofructokinase-1 activity, glucose 6-phosphate dehydrogenase (G6PD) activity, and induced ATP depletion, oxidative stress, autophagy, and apoptosis. Small interfering RNA-mediated TIGAR inhibition prevented the aforementioned malevolent effects and protected the kidneys from functional and histological damage. After mild ischemia, but not severe ischemia, G6PD activity and NADPH levels were restored, suggesting that TIGAR activation may redirect the glycolytic pathway into gluconeogenesis or the pentose phosphate pathway to produce NADPH. The increased level of NADPH maintained the level of GSH to scavenge ROS, resulting in a lower sensitivity of PST cells to injury. Under severe ischemia, G6PD activity and NADPH levels were reduced during reperfusion; however, blockade of TIGAR enhanced their levels and reduced oxidative stress and apoptosis. Collectively, these results demonstrate that inhibition of TIGAR may protect PST cells from energy depletion and apoptotic cell death in the setting of severe ischemia-reperfusion injury. However, under low ischemic burden, TIGAR activation induces the pentose phosphate pathway and autophagy as a protective mechanism.

Download Full-text

Does G6PD-Deficiency Related Oxidative Stress and Hemolysis Affect Erythroid Response to Erythropoietic Stimulating Agents (ESA) in Myelodysplastic Patients?

Clinical Lymphoma Myeloma & Leukemia ◽

10.1016/j.clml.2018.07.168 ◽

2018 ◽

Vol 18 ◽

pp. S259

Author(s):

Federica Pilo ◽

Valeria Santini ◽

Anna Angela DiTucci ◽

Valentina Serreli ◽

Giorgio La Nasa

Keyword(s):

Oxidative Stress ◽

G6pd Deficiency ◽

Erythroid Response

Download Full-text

Glucose-6-Phosphate Dehydrogenase Deficiency among Children Attending the Emergency Department of Yankin Children’s Hospital, Yangon

Myanmar Health Sciences Research Journal ◽

10.34299/mhsrj.00938 ◽

2019 ◽

Vol 31 (2) ◽

pp. 143-147

Keyword(s):

Emergency Department ◽

G6pd Deficiency ◽

Who Classification ◽

G6pd Activity ◽

World Health ◽

In Vitro Test ◽

Children's Hospital ◽

Severe Deficiency ◽

Test Kit ◽

Children’S Hospital

Yankin Children’s Hospital is one of the tertiary children hospitals in Myanmar, where some oxidative medications are commonly used in the management of illnesses. Paediatrician’s awareness of G6PD status in this population is very important for effective management and prevention of complications in G6PD deficient children. This preliminary study aims to determine the prevalence of G6PD deficiency according to WHO classification among children seeking medical care at Emergency Department of Yankin Children’s Hospital (YKCH). It was a cross-sectional descriptive study on 124 children, aged 1 month to 13 years. G6PD enzyme activity was determined by spectrophotometric assay within 24 hours of sample collection. Randox G6PD quantitative in vitro test kit (Randox Laboratories, Crumlin, UK) was used and G6PD activity was calculated as unit per gram (U/g) of haemoglobin (Hb). For classification of G6PD deficiency, 10% and 60% level of normal enzyme activities were calculated according to the suggestion by World Health Organization (WHO); G6PD activity <10% was defined as severe deficiency and 10-60% was defined as moderate deficiency. According to WHO classification, 18.5% (23/124) of children in this study was classified as G6PD deficient, with 3.2% severe deficiency and 15.3% moderate deficiency. The prevalence of G6PD deficiency in Myanmar children is higher than the previous reported prevalence if quantitative spectrophotometric method is used for diagnosis, detecting more individuals with moderate deficiency. The high prevalence of G6PD deficiency in this study warrants for the need to do neonatal screening to avoid the potentially fatal complications of this disease.

Download Full-text

A Rare Case of Coexistence of Homozygous β-Thalassaemia and Glucose 6 Phosphate Dehydrogenase Deficiency

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2020/44968.14085 ◽

2020 ◽

Author(s):

Jitendar Mohan Khunger ◽

Monika Gupta ◽

Ankur Jain ◽

Monica Khunger Malhotra

Keyword(s):

Oxidative Stress ◽

Blood Cells ◽

G6pd Deficiency ◽

Rare Case ◽

Dehydrogenase Deficiency ◽

Globin Gene ◽

Genetic Abnormality ◽

Wide Range ◽

Symptomatic Anaemia ◽

Glucose 6 Phosphate Dehydrogenase

β-thalassaemia is one of the most prevalent autosomal disorders worldwide. Mutations/deletions in globin gene underlie deficiencies in Haemoglobin (Hb) production, which can interfere with oxygen delivery by Hb, resulting in thalassaemias causing anaemias with a wide range of disease severity. Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is a genetic abnormality resulting in inadequate amount of G6PD in the Red Blood Cells (RBCs). In patients with G6PD deficiency, the reduced or absent activity of the enzyme in RBCs causes premature haemolysis and symptomatic anaemia. The marked oxidative stress caused by homozygous β-thalassaemia is apparently incompatible with G6PD deficiency. Here, a rare case of six-month-old male child is described who presented with severe pallor hepato-splenomegaly and these two conditions co-existed in this patient.

Download Full-text

Relationship between Type 2 Diabetes and Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency and Their Effect on Oxidative Stress

Journal of Diabetes & Metabolism ◽

10.4172/2155-6156.1000800 ◽

2018 ◽

Vol 09 (08) ◽

Cited By ~ 1

Author(s):

Godwill Azeh Engwa ◽

Friday Nweke Nwalo ◽

Gregory Eze Chibuzor ◽

Endaline Chiamaka Ejiagha ◽

Micheal Chinweuba Abonyi ◽

...

Keyword(s):

Oxidative Stress ◽

Type 2 Diabetes ◽

G6pd Deficiency ◽

Glucose 6 Phosphate Dehydrogenase

Download Full-text

Glucose-6 Phosphate dehydrogenase deficiency contributes to metabolic abnormality and pulmonary hypertension

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00165.2020 ◽

2021 ◽

Author(s):

Mathews Valuparampil Varghese ◽

Joel James ◽

Olga Rafikova ◽

Ruslan Rafikov

Keyword(s):

Oxidative Stress ◽

Pulmonary Hypertension ◽

G6pd Deficiency ◽

Pentose Phosphate ◽

Metabolic Reprogramming ◽

Pulmonary Vasculature ◽

Barrier Dysfunction ◽

Metabolic Switch ◽

Acid Pathway ◽

Deficient Mice

We have previously reported that several patients with idiopathic pulmonary hypertension (PH) had different types of G6PD deficiency. However, the role of G6PD in PH is multifactorial because G6PD is involved in controlling oxidative stress, metabolic switch, and red blood cell fragility. To delineate the contribution of G6PD in PH pathogenesis, we utilized a mouse line with decreased expression of G6PD (10% from wild-type level). We confirmed that mice with G6PD deficiency develop spontaneous pulmonary hypertension with pulmonary artery and right heart remodeling. G6PD deficiency resulted in increased free hemoglobin and activation of the p38 pathway, which we recently reported induces the development of PH in the sugen/hypoxia model via endothelial barrier dysfunction. Metabolomics analysis of G6PD deficient mice indicates the switch to alternative metabolic fluxes that feed into the pentose phosphate pathway (PPP), resulting in the upregulation of oxidative stress, fatty acid pathway, and reduction in pyruvate production. Thus, G6PD deficiency did not reduce PPP flux that is important for proliferation but activated collateral pathways at the cost of increased oxidative stress. Indeed, we found upregulation of myo-inositol oxidase, reduction in GSH/GSSG ratio, and increased nitration in the lungs of G6PD deficient mice. Increased oxidative stress also results in the activation of PI3K, ERK1/2, and AMPK that contributes to the proliferation of pulmonary vasculature. Therefore, G6PD deficiency has a multi-modal effect, including hemolysis, metabolic reprogramming, and oxidative stress leading to PH phenotype in mice.

Download Full-text