Screening, genotyping and haematological analysis of glucose-6-phosphate dehydrogenase deficiency in the blood donors of Wuxi City, China.

BACKGROUND AND OBJECTIVES: To investigate the prevalence, genotype and haematological characteristics of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the blood donor population of Wuxi area (Jiangsu Province, China) and to assess the impact of their red blood cell (RBC) units on clinical transfusion. MATERIALS AND METHODS: We conducted genotyping and large-scale screening for G6PD enzyme activity in the blood donors of Wuxi City. In addition, we assessed the haematological parameters of G6PD-deficient and non-deficient blood donors, and investigated the adverse transfusion reactions in patients transfused with G6PD-deficient blood. RESULTS: We investigated 17,113 blood donors, among whom 44 (0.26%) were tested positive for G6PD deficiency. We identified 40 G6PD gene variants, among which c.1388G>A, c.1376G>T, c.1024C>T and c.95A>G were common. In addition, we identified two novel G6PD gene variants, c.1312G>A and c.1316G>A. The G6PD-deficient and non-deficient blood samples showed a significant difference in the RBC, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), RBC distribution width, total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) values. However, the two samples showed no significant difference in the haemolysis rate at the end of the storage period. Finally, transfusion with G6PD-deficient RBC units did not lead to any adverse transfusion reactions. CONCLUSION: The positive rate of G6PD deficiency in the blood donor population of Wuxi City is 0.26%, and the genetic variants identified in this population are consistent with the common genetic variants observed in the Chinese population. Blood centres can establish a database on G6PD-deficient blood donors and mark their RBC units to avoid their use for special clinical patients.

The Emerging Roles of the Metabolic Regulator G6PD in Human Cancers.

Metabolic reprogramming, especially reprogrammed glucose metabolism, is a well-known cancer hallmark related to various characteristics of tumor cells, including proliferation, survival, metastasis, and drug resistance. Glucose-6-phosphate dehydrogenase (G6PD) is the first and rate-limiting enzyme of the pentose phosphate pathway (PPP), a branch of glycolysis, that converts glucose-6-phosphate (G6P) into 6-phosphogluconolactone (6PGL). Furthermore, PPP produces ribose-5-phosphate (R5P), which provides sugar-phosphate backbones for nucleotide synthesis as well as nicotinamide adenine dinucleotide phosphate (NADPH), an important cellular reductant. Several studies have shown enhanced G6PD expression and PPP flux in various tumor cells, as well as their correlation with tumor progression through cancer hallmark regulation, especially reprogramming cellular metabolism, sustaining proliferative signaling, resisting cell death, and activating invasion and metastasis. Inhibiting G6PD could suppress tumor cell proliferation, promote cell death, reverse chemoresistance, and inhibit metastasis, suggesting the potential of G6PD as a target for anti-tumor therapeutic strategies. Indeed, while challenges-including side effects-still remain, small-molecule G6PD inhibitors showing potential anti-tumor effect either when used alone or in combination with other anti-tumor drugs have been developed. This review provides an overview of the structural significance of G6PD, its role in and regulation of tumor development and progression, and the strategies explored in relation to G6PD-targeted therapy.

Impairment of Invasion and Maturation and Decreased Selectivity of Plasmodium falciparum in G6PD Viangchan and Mahidol Variants.

BACKGROUND: Protection against Plasmodium falciparum is observed in a population deficient in glucose-6-phosphate dehydrogenase (G6PD), particularly in African and Mediterranean regions. However, such protection remains unknown among G6PD-deficient individuals in Southeast Asia. METHODS: In this study, we assessed the invasion and maturation of P falciparum K1 in a culture of erythrocytes isolated from Thai subjects carrying Viangchan (871G > A) and Mahidol (487G > A). RESULTS: We found that the parasites lost their ability to invade hemizygous and homozygous G6PD-deficient erythrocytes of Viangchan and Mahidol variants in the second and third cycles of intraerythrocytic development. It is interesting to note that P falciparum parasites selectively grew in erythrocytes from hemi- and homozygous genotypes with normal G6PD activity. Moreover, externalization of phosphatidylserine upon P falciparum infection was significantly increased only in Viangchan hemizygous variant cells. CONCLUSIONS: This study is the first to show that blockage of invasion in long-term culture and potentially enhanced removal of parasitized erythrocytes were observed for the first time in erythrocytes from Viangchan and Mahidol G6PD-deficient individuals.

Management of children with glucose-6-phosphate dehydrogenase deficiency presenting with acute haemolytic crisis during the SARs-COV-2 pandemic.

BACKGROUND AND OBJECTIVES: Shortage of blood during the severe acute respiratory syndrome-COV-2 (SARs-COV-2) pandemic impacted transfusion practice. The primary aim of the study is to assess management of acute haemolytic crisis (AHC) in glucose-6-phosphate dehydrogenase(G6PD)- deficient children during SARs-COV-2 pandemic, and then to assess blood donation situation and the role of telemedicine in management. METHODS: Assessment of G6PD-deficient children attending the Emergency Department (ER) with AHC from 1 March 2020 for 5 months in comparison to same period in the previous 2 years, in three paediatric haematology centres. AHC cases presenting with infection were tested for SARs-COV-2 using RT-PCR. Children with Hb (50-65 g/L) and who were not transfused, were followed up using telemedicine with Hb re-checked in 24 h. RESULTS: A 45% drop in ER visits due to G6PD deficiency-related AHC during SARs-COV-2 pandemic in comparison to the previous 2 years was observed. 10% of patients presented with fever and all tested negative for COVID-19 by RT-PCR. 33% of patients had Hb < 50 g/L and were all transfused. 50% had Hb between 50 and 65 g/L, half of them (n = 49) did not receive transfusion and only two patients (4%) required transfusion upon follow up. A restrictive transfusion strategy was adopted and one of the reasons was a 39% drop in blood donation in participating centres. CONCLUSION: Fewer G6PD-deficient children with AHC visited the ER during SARs-COV-2 and most tolerated lower Hb levels. Telemedicine was an efficient tool to support their families. A restrictive transfusion strategy was clear in this study.

Randomised controlled trial of glucose-6-phosphate dehydrogenase deficient versus non-deficient red blood cell transfusion in patients with hypoproliferative anaemia.

BACKGROUND: Recent studies revealed the glucose-6-phosphate dehydrogenase (G-6-PD) deficiency prevalence of 7.7-10% among Thai blood donors. Transfusion of red blood cells (RBCs) from these subjects potentially causes haemolysis in recipients. METHODS: RBC units from the National Blood Centre were sampled to assess G-6-PD levels using spectrophotometry. Patients with pure underproduction anaemia requiring blood transfusion were randomised to receive G-6-PD-deficient versus normal ABO-matched RBCs. Pre- and 48-h post-transfusion indirect bilirubin, haemoglobin, haematocrit, lactate dehydrogenase (LDH) and haptoglobin were measured. RESULTS: From April 2020 to March 2021, 374 RBC units were tested for G-6-PD, and that 25 were found to be G-6-PD deficient. Twelve units of G-6-PD-deficient RBCs and 14 units of normal RBCs were given to patients who met the inclusion criteria. The median (interquartile range) increases of indirect bilirubin in G-6-PD-deficient (N = 11) versus normal RBCs (N = 13) were + 0.12 (0.27) versus + 0.01 (1.3) mg/dl, p = 0.030), respectively. The median increases of haemoglobin were 1.00 (0.50) versus + 0.80 (0.95), p = 0.910, respectively. The increases in haematocrit were 2.59 (1.9) versus 2.29 (2.1), p = 0.733, respectively. There were no significant differences in changes of LDH and haptoglobin levels and no transfusion reactions. DISCUSSION: G-6-PD-deficient packed red cells were associated with mildly elevated indirect bilirubin after transfusion, but there was no observed clinical symptoms.

Associations between the TNMD rs4828038 and ACE2 rs879922 polymorphisms and preeclampsia susceptibility: a case-control study.

A case-control study was designed to investigate the association between the angiotensin converting enzyme 2 (ACE2) rs879922, glucose-6-phosphate dehydrogenase (G6PD) rs1050828, and tenomodulin (TNMD) rs4828038 single nucleotide polymorphisms (SNPs), and preeclampsia. A total of 356 Han Chinese pregnant women (170 controls and 186 cases) were recruited into the study. ACE2 rs879922, G6PD rs1050828, and TNMD rs4828038 were tested by the targeted next-generation sequencing technology and the data were analyzed using SPSS version 18. Genotyping of results revealed that patients with the CC/CT genotype in SNP rs4828038 or CC/CG genotype in SNP rs879922 had a significantly decreased susceptibility to late-onset preeclampsia (CC/CT versus TT: OR = 0.543, 95% CI = 0.378 to 0.779, p = .001; CC/CG versus GG: OR = 0.510, 95% CI = 0.038 to 0.860, p = .012). Our study found that the polymorphisms TNMD rs4828038 and ACE2 rs879922 might be associated with late-onset preeclampsia.IMPACT STATEMENTWhat is already known on this subject? Preeclampsia is associated with multiple SNPs, and ACE2 rs879922, G6PD rs1050828, and TNMD rs4828038 are related to essential hypertension and glucose and lipid metabolism disorders. Essential hypertension, diabetes, and dyslipidemia are risks for preeclampsia. The associations between those three SNPs and preeclampsia have not been reported.What do the results of this study add? The polymorphisms of TNMD rs4828038 and ACE2 rs879922 might be associated with the risk of late-onset preeclampsia. There was no relationship between SNP rs1050828 and preeclampsia.What are the implications of these findings for clinical practice and/or further research? TNMD rs4828038 and ACE2 rs879922 might be target sites for genetic diagnosis and therapy, and the levels of mRNA and protein in pregnant women with preeclampsia should be further tested.

A computational study of structural differences of binding of NADP+ and G6P substrates to G6PD Mediterraneanc.563T, G6PD A-c.202A/c.376G, G6PD Cairoc.404C and G6PD Gazac.536A mutations.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked inherited enzymopathic disorder that may lead to transfusion-requiring acute hemolytic anemia (AHA) triggered by fava beans ingestion, infection or some drugs. The gene encoding for G6PD carries a large number of genetic variants that have varying pathogenicity. We reported on three G6PD variants in the Gaza Strip Palestinian population with differing clinical impacts and frequencies: G6PD Mediterraneanc.563T, African G6PD A-c.202A/c.376G, and G6PD Cairoc.404C. We also identified a novel G6PD missense (Ser179Asn) mutation c.536G > A "G6PD Gaza". In this work we explore the effect of these four genetic variants on the structural and substrate (NADP+ and G6P) binding characteristics of the G6PD enzyme using the Monte Carlo (MC) flexible docking and molecular dynamics (MD) simulation approaches. We report that G6PD A-c.202A/c.376G, G6PD Mediterraneanc.563T, G6PD Cairoc.404C and G6PD Gazac.536A mutations cause significant structural changes in G6PD enzyme to induce conformational instability leading to the loss of binding of one or both substrates and are causative of G6PD deficiency.

A new colorimetric assay for sensitive detection of glucose-6-phosphate dehydrogenase deficiency based on silver nanoparticles.

Glucose-6-phosphate dehydrogenase (G6PD) is the principal enzyme in the pentose phosphate pathway that plays a fundamental role in the production of nicotinamide adenine dinucleotide phosphate, which is very important in preventing the oxidation of cells, especially red blood cells. This enzyme deficiency was associated with many disorders, the most common of which were hemolysis episodes. In the last decade, nanoparticles have been used to design optical and electronic sensors due to their unique properties. This report presents a new colorimetric method that used silver nanoparticles to detect glucose 6-phosphate dehydrogenase activity directly. The glucose-6-phosphate dehydrogenase detection mechanism was based on an aggregation of silver nanoparticles, leading to increased nanoparticle size, which causes discoloration. In the presence of the enzyme, the color of the solution was yellow, and when the enzyme was not present, the color of the solution was grayish. Utilizing this method, colorimetric sensing of glucose 6-phosphate dehydrogenase was gained with a detection limit of 0.009 U ml-1and a linear range of 0-16.0 U ml-1. In this way, the presence or absence of the enzyme can be easily detected with the naked eye during one step.

Glucose-6-Phosphate Dehydrogenase Deficiency: An Overview of the Prevalence and Genetic Variants in Saudi Arabia.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common inherited metabolic abnormality of red blood cells (RBCs), affecting 400 million individuals worldwide. Patients with G6PD deficiency anemia might exhibit severe clinical manifestations, including acute hemolytic anemia (AHA), neonatal hyperbilirubinemia (jaundice), favism, and chronic non-spherocytic hemolytic anemia (CNSHA). The aim of the current review is to report the prevalence and genetic variants of G6PD deficiency anemia in Saudi Arabia. The scientific literature was reviewed for reports on G6PD deficiency in Saudi Arabia. The incidence rate of G6PD deficiency is very high in Saudi Arabia and varies from Province to Province. As reported by the Ministry of Health, the prevalence of G6PD deficiency in Saudi Arabia is 8.4% among males. The pattern and distribution of the genetic mutations also vary. Some of the genetic mutations of G6PD deficiency have been associated with clinical manifestations including hemolysis, especially in neonates. Several studies have reported known common variants such as Mediterranean and A-, as well as rare variants such as Nara, Sibiri, and Viangchan in the Saudi population. Early detection, characterization, and understanding of the phenotypic and molecular patterns of G6PD deficiency in Saudi Arabia are needed for better management and control of the disease. Thus, neonatal screening for G6PD deficiency, family counseling, and public awareness of the disease should be established.

IL-6-induced acetylation of E2F1 aggravates oxidative damage of retinal pigment epithelial cell line.

Oxidative damage in retinal pigment epithelial cells (RPE) is considered to be a crucial pathogenesis of age-related macular degeneration (AMD). Although dysregulation of the DNA repair system has been found in RPE cells of AMD patients, the detailed molecular mechanisms of this dysregulation and their relationship with the intraocular microenvironment of AMD patients remain unclear. Here, we established an RPE model of H2O2-induced oxidative stress and found that Sirtuin 1 (Sirt1)-mediated deacetylation of E2F transcription factor 1 (E2F1) was required for oxidation resistance in RPE cells. Moreover, E2F1 induced the expression of the chromatin-binding protein, high mobility group AT-Hook 1 (HMGA1), which promoted the transcription of glucose 6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway, to increase NADPH level for antioxidant defense. Interrupting the E2F1/HMGA1/G6PD regulatory axis increased reactive oxygen species (ROS) levels, DNA damage, and apoptosis in RPE cells under oxidative stress. Notably, interleukin 6 (IL-6), an inflammatory cytokine that is known to be upregulated in the intraocular fluid of AMD patients, induced phosphorylation (S47) of Sirt1 by activating PI3K/AKT/mTOR signaling, thereby inhibiting Sirt1 activity and increasing the acetylation of E2F1. Specific inhibitors of PI3K/AKT/mTOR signaling decreased DNA damage and ROS while increasing NADPH in RPE cells. Collectively, our findings demonstrate that IL-6-induced acetylation of E2F1 impairs the antioxidant capacity of RPE cells by disturbing the pentose phosphate pathway, which elucidates a relationship between the intraocular microenvironment and RPE oxidative damage in AMD and provides a possible therapeutic target for AMD.

Fabricating cholyglycine-glucose-6-phosphate dehydrogenase conjugates for cholyglycine detection.

To establish cholyglycine (CG) detection via enzyme multiplied immunoassay technique (EMIT), glucose-6-phosphate dehydrogenase (G6PD) was used as a reporter enzyme to prepare hapten-enzyme conjugate. Gel electrophoresis and UV scanning demonstrated that G6PD was successfully labeled with cholyglycine and CG-G6PD conjugate was obtained. Furthermore, the effects of various parameters on the preparation of CG-G6PD conjugates were investigated. Consequently, CG amount, NADH, D-glucose-6-phosphate (G6P), phosphate buffer and the pH, and ionic strength of solution had important effects on the residual activity of CG-G6PD. Moreover, CG amount, the pH, and G6P played important roles in changing CG labeling location on G6PD. Using the CG-G6PD conjugate as test kit, the cholyglycine-EMIT calibration curve was established, which could be employed in clinical detection of cholyglycine. This study provides some valuable information for preparing hapten-G6PD conjugates. This article is protected by copyright. All rights reserved.

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency and Late-stage Age-Related Macular Degeneration.

Purpose: Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in Western Countries. Evidence indicates that Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, a common genetic abnormality, may protect against ischemic heart and cerebrovascular disease, ocular vascular disorders, and colorectal cancer. This study was undertaken to ascertain whether G6PD deficiency may protect against AMD. Materials and Methods: 79 men with late-stage AMD and 79 male, age-matched cataract controls without AMD were recruited in March-December 2016. Smoking status, clinical history, and drug use were recorded. A blood sample was taken from each participant. Complete blood count, hemoglobin, glucose, creatinine, cholesterol, triglycerides, transaminases, bilirubin, and erythrocyte G6PD activity were measured. Stepwise logistic regression was used to investigate the association between G6PD deficiency and AMD. Results: G6PD deficiency was found in 7 (8.9%) AMD patients and 8 (10.1%) controls, a not statistically significant difference. Stepwise logistic regression disclosed that AMD was significantly associated with increased diastolic blood pressure (OR=1.09, 95% CI=1.03-1.15, P=0.02) and LDL-cholesterol (OR=1.02, 95% CI=1.0001-1.03, P=0.049) and lower values of white blood cell (WBC) count (OR=0.71, 95% CI=0.56-0.88, P=0.02) and aspartate aminotransferase (AST) (OR=0.92, 95% CI=0.85-0.99, P=0.044). Conclusion: Results suggest that G6PD deficiency has no protective effect on nor is a risk factor for AMD. Larger studies are necessary to confirm whether increased diastolic blood pressure and LDL-cholesterol and lower values of WBC count and AST are risk factors for AMD.

Molecular Cloning and Exploration of the Biochemical and Functional Analysis of Recombinant Glucose-6-Phosphate Dehydrogenase from Gluconoacetobacter diazotrophicus PAL5.

Gluconacetobacter diazotrophicus PAL5 (GDI) is an endophytic bacterium with potential biotechnological applications in industry and agronomy. The recent description of its complete genome and its principal metabolic enzymes suggests that glucose metabolism is accomplished through the pentose phosphate pathway (PPP); however, the enzymes participating in this pathway have not yet been characterized in detail. The objective of the present work was to clone, purify, and biochemically and physicochemically characterize glucose-6-phosphate dehydrogenase (G6PD) from GDI. The gene was cloned and expressed as a tagged protein in E. coli to be purified by affinity chromatography. The native state of the G6PD protein in the solution was found to be a tetramer with optimal activity at pH 8.8 and a temperature between 37 and 50 °C. The apparent Km values for G6P and nicotinamide adenine dinucleotide phosphate (NADP+) were 63 and 7.2 µM, respectively. Finally, from the amino acid sequence a three-dimensional (3D) model was obtained, which allowed the arrangement of the amino acids involved in the catalytic activity, which are conserved (RIDHYLGKE, GxGGDLT, and EKPxG) with those of other species, to be identified. This characterization of the enzyme could help to identify new environmental conditions for the knowledge of the plant-microorganism interactions and a better use of GDI in new technological applications.

Glucose-6-Phosphate Dehydrogenase Deficiency Mimicking Atypical Hemolytic Uremic Syndrome.

A 4-year-old boy presented with nonimmune hemolysis, thrombocytopenia, and acute kidney injury. Investigations for an underlying cause failed to identify a definitive cause and a putative diagnosis of complement-mediated atypical hemolytic uremic syndrome (aHUS) was made. The patient was started initially on plasma exchange and subsequently eculizumab therapy, after which his kidney function rapidly improved. While on eculizumab therapy, despite adequate complement blockade, he presented 2 more times with hemolytic anemia and thrombocytopenia, but without renal involvement. Genetic analysis did not uncover a mutation in any known aHUS gene (CFH, CFI, CFB, C3, CD46, THBD, INF2, and DGKE) and anti-factor H antibodies were undetectable. Whole-exome sequencing was undertaken to identify a cause for the eculizumab resistance. This revealed a pathogenic variant in G6PD (glucose-6-phosphate dehydrogenase), which was confirmed by functional analysis demonstrating decreased erythrocyte G6PD activity. Eculizumab therapy was withdrawn. Complement-mediated aHUS is a diagnosis of exclusion and this case highlights the diagnostic difficulty that remains without an immediately available biomarker for confirmation. This case of G6PD deficiency presented with a phenotype clinically indistinguishable from complement-mediated aHUS. We recommend that G6PD deficiency be included in the differential diagnosis of patients presenting with aHUS and suggest measuring erythrocyte G6PD concentrations in these patients.

Prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency among malaria patients in Upper Myanmar.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD; EC 1.1.1.49) deficiency is one of the most common X-linked recessive hereditary disorders in the world. Primaquine (PQ) has been used for radical cure of P. vivax to prevent relapse. Recently, it is also used to reduce P. falciparum gametocyte carriage to block transmission. However, PQ metabolites oxidize hemoglobin and generate excessive reactive oxygen species which can trigger acute hemolytic anemia in malaria patients with inherited G6PD deficiency. METHODS: A total of 252 blood samples collected from malaria patients in Myanmar were used in this study. G6PD variant was analysed by a multiplex allele specific PCR kit, DiaPlexC™ G6PD Genotyping Kit [Asian type]. The accuracy of the multiplex allele specific PCR was confirmed by sequencing analysis. RESULTS: Prevalence and distribution of G6PD variants in 252 malaria patients in Myanmar were analysed. Six different types of G6PD allelic variants were identified in 50 (7 females and 43 males) malaria patients. The predominant variant was Mahidol (68%, 34/50), of which 91.2% (31/34) and 8.8% (3/34) were males and females, respectively. Other G6PD variants including Kaiping (18%, 9/50), Viangchan (6%, 3/50), Mediterranean (4%, 2/50), Union (2%, 1/50) and Canton (2%, 1/50) were also observed. CONCLUSIONS: Results of this study suggest that more concern for proper and safe use of PQ as a radical cure of malaria in Myanmar is needed by combining G6PD deficiency test before PQ prescription. Establishment of a follow-up system to monitor potential PQ toxicity in malaria patients who are given PQ is also required.

Genetic Polymorphisms of Glucose-6-Phosphate Dehydrogenase in Lagos, Nigeria.

Glucose-6-phosphate dehydrogenase (G6PD) is an essential enzyme in the pentose phosphate pathway that prevents oxidative damage to cells. This study determined the genotypic and allelic frequencies of G6PD G202A and A376G and also investigated correlation between G6PD polymorphisms and hemoglobin (Hb) phenotypes in children in Lagos, Nigeria. Seventy-eight children [55 with Hb AA (ßΑ/ßA) and 23 with Hb AS (ßΑ/ßS) trait] and 65 Hb SS (ßS/ßS) (HBB: c.20A>T) subjects in steady state with age range between 5-15 years were recruited for the study. Hemoglobin phenotypes of all study participants were carried out using alkaline electrophoresis and solubility tests. Genomic DNA was extracted from whole blood and restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) was used to determine the G202A and the A376G mutations of the G6PD gene. The genotype and allele distributions of G6PD G202A and A376G according to the Hb phenotypes were not statistically significant (p > 0.05). The minor allele frequency 202A was 0.15 (15.0%) and 0.14 (14.0%) in cases and controls, respectively. The overall frequency of 376G allele in the case group was 0.35 (35.0%) and 0.38 (38.0%) in the control group. No statistical significance was observed in the genotype and allele distributions of A376G in both the case and control groups (p > 0.05). The G6PD A- frequency in Hb SS subjects and the control group were 6.2 and 2.6%, respectively. G6PD G202A and A376G polymorphisms were not associated with Hb phenotypes and the allele distributions of 202A and 376G in this study are typical of West African populations.

Severe haemolysis and renal failure precipitated by hepatitis E virus in G6PD Deficient patient: A case report.

Hepatitis E virus is the etiological agent for Hepatitis E infection, which is congruent to Hepatitis A infection. The clinical spectrum of the disease range from asymptomatic self-limiting disease which requires no treatment to life threatening fulminant liver disease in pregnancy, G6PD deficient and post-liver transplant patients, which necessitate urgent treatment. Similarly we are reporting a case of a 28 year old male with no previous known comorbids, who presented in emergency department with low grade fever, yellow discolouration of eyes and upper abdominal pain for last 5-6 days. We affirmed the diagnosis of acute viral hepatitis E with G6PD deficiency. This case had a different prospect of HEV infection and its coexistence with G6PD deficiency, which lead to investigations, management and avoidance of complications of the disease.

Subversion of Schwann Cell Glucose Metabolism by Mycobacterium leprae.

Mycobacterium leprae, the intracellular etiological agent of leprosy, infects Schwann promoting irreversible physical disabilities and deformities. These cells are responsible for myelination and maintenance of axonal energy metabolism through export of metabolites, such as lactate and pyruvate. In the present work, we observed that infected Schwann cells increase glucose uptake with a concomitant increase in glucose-6-phosphate dehydrogenase (G6PDH) activity, the key enzyme of the oxidative pentose pathway. We also observed a mitochondria shutdown in infected cells and mitochondrial swelling in pure neural leprosy nerves. The classic Warburg effect described in macrophages infected by Mycobacterium avium was not observed in our model, which presented a drastic reduction in lactate generation and release by infected Schwann cells. This effect was followed by a decrease in lactate dehydrogenase isoform M (LDH-M) activity and an increase in cellular protection against hydrogen peroxide insult in a pentose phosphate pathway and GSH-dependent manner. M. leprae infection success was also dependent of the glutathione antioxidant system and its main reducing power source, the pentose pathway, as demonstrated by a 50 and 70% drop in intracellular viability after treatment with the GSH synthesis inhibitor buthionine sulfoximine, and aminonicotinamide (6-ANAM), an inhibitor of G6PDH 6-ANAM, respectively. We concluded that M. leprae could modulate host cell glucose metabolism to increase the cellular reducing power generation, facilitating glutathione regeneration and consequently free-radical control. The impact of this regulation in leprosy neuropathy is discussed.

Glutathione Depletion, Pentose Phosphate Pathway Activation, and Hemolysis in Erythrocytes Protecting Cancer Cells from Vitamin C-induced Oxidative Stress.

The discovery that oxidized vitamin C, dehydroascorbate (DHA), can induce oxidative stress and cell death in cancer cells has rekindled interest in the use of high dose vitamin C (VC) as a cancer therapy. However, high dose VC has shown limited efficacy in clinical trials, possibly due to the decreased bioavailability of oral VC. Because human erythrocytes express high levels of Glut1, take up DHA, and reduce it to VC, we tested how erythrocytes might impact high dose VC therapies. Cancer cells are protected from VC-mediated cell death when co-cultured with physiologically relevant numbers of erythrocytes. Pharmacological doses of VC induce oxidative stress, GSH depletion, and increased glucose flux through the oxidative pentose phosphate pathway (PPP) in erythrocytes. Incubation of erythrocytes with VC induced hemolysis, which was exacerbated in erythrocytes from glucose-6-phosphate dehydrogenase (G6PD) patients and rescued by antioxidants. Thus, erythrocytes protect cancer cells from VC-induced oxidative stress and undergo hemolysis in vitro, despite activation of the PPP. These results have implications on the use of high dose VC in ongoing clinical trials and highlight the importance of the PPP in the response to oxidative stress.