Generation of human induced pluripotent stem cell line (MUi033-A) from a male with homozygous for Hemoglobin E

Hemoglobin E (HbE), a common variant in Southeast Asian populations, results from a G to A substitution at codon 26 of the HBB gene, causing abnormal Hb and mild β-thalassemia-like symptoms. Here, we derived an induced pluripotent stem cell (iPSC) line, named MUi033-A, from a male homozygous for HbE. The iPSC line demonstrates a normal karyotype and embryonic stem cell-like properties including pluripotency gene expression, and tri-lineage differentiation potential. This iPSC resource holds the potential for investigating gene therapy targeting HbE mutation.

How do we translate gaps and unmet needs of blood management for thalassemia into a collaborative implementation framework?

BACKGROUND AND OBJECTIVE

The mainstay of management for thalassemia is regular blood transfusions. However, gaps and unmet needs of blood services for thalassemia are still not clearly identified and addressed in Thailand, a country prevalent with thalassemia. What can be a collaborative implementation framework that helps advance practices and policies relating to blood management for thalassemia?

METHODS

The first Blood & Beyond Roundtable Discussion was held in July 2022 to gather the current situation, gaps, and unmet needs of blood services for thalassemia from multidisciplinary experts and thalassemic patients. The Implementation Guide as suggested by the Centre for Effective Services was applied as a tool to consolidate information from the discussions and construct the collaborative implementation framework.

RESULTS

The National Blood Center and hospitals in Thailand followed the missions specified in the National Blood Policy and the standard guidelines to ensure the best practice of blood management for thalassemia. However, there were six gaps and unmet needs identified from the discussions. After all discussion points were mapped onto the framework, an implementation plan comprised of five specific activities became clear and actionable.

CONCLUSION

Without the complete information from both experts and patients, the implementation plan would not have been successfully constructed. The method that we employed to translate all information into the framework can be adapted by other countries to develop their own specific framework efficiently.

A comprehensive study of immune function and immunophenotyping of white blood cells from β-thalassaemia/HbE patients on hydroxyurea supports the safety of the drug

Hydroxyurea (HU) (hydroxycarbamide) is used as a therapeutic option in β-thalassaemia to increase fetal haemoglobin, which results in a reduced requirement for blood transfusion. However, a potential serious adverse effect of HU is neutropenia. Abnormal neutrophil maturation and function in β-thalassaemia/HbE patients are well documented. This raises questions about the effect of the drug with regards to the immune response these patients. This study investigated the effects of HU treatment on both innate and adaptive immunity in a cross-sectional study of 28 β-thalassaemia/HbE patients who had received HU treatment (BE+HU) as compared with 22 β-thalassaemia/HbE patients who had not received HU (BE-HU) and 26 normal subjects. The expression of PU.1 and C/EBPβ, transcription factors, which are associated with neutrophil maturation, was significantly reduced in BE+HU patients as compared with BE-HU patients and normal subjects. Interestingly, C3bR expression on neutrophils and their oxidative burst activity in BE+HU were restored to close to normal levels when compared with BE-HU. There was no observed effect of HU on monocytes, myeloid derived suppressor cells (both granulocytic and monocytic subsets), CD4⁺ T cells, CD8⁺ T cells, complement levels and serum immunoglobulin levels in this study. The full immunophenotyping analysis in this study indicates that HU therapy in β-thalassaemia/HbE patients does not significantly compromise the immune response.

Induction of fetal hemoglobin: Lentiviral shRNA knockdown of HBS1L in β0-thalassemia/HbE erythroid cells

Imbalanced globin chain output contributes to thalassemia pathophysiology. Hence, induction of fetal hemoglobin in β-thalassemia and other β-hemoglobinopathies are of continuing interest for therapeutic approaches. Genome-wide association studies have identified three common genetic loci: namely β-globin (HBB), an intergenic region between MYB and HBS1L, and BCL11A underlying quantitative fetal hemoglobin production. Here, we report that knockdown of HBS1L (all known variants) using shRNA in early erythroblast obtained from β0-thalassemia/HbE patients triggers an upregulation of γ-globin mRNA 1.69 folds. There is modest perturbation of red cell differentiation assessed by flow cytometry and morphology studies. The levels of α- and β-globin mRNAs are relatively unaltered. Knockdown of HBS1L also increases the percentage of fetal hemoglobin around 16.7 folds when compared to non-targeting shRNA. Targeting HBS1L is attractive because of the potent induction of fetal hemoglobin and the modest effect on cell differentiation.

Effects of green tea extract treatment on erythropoiesis and iron parameters in iron-overloaded β-thalassemic mice

β-Thalassemia is characterized by ineffective erythropoiesis leading to chronic anemia. Thus, increased iron absorption from the duodenum and via blood transfusions is required to maintain normal blood hemoglobin (Hb) levels and iron chelators in the removal of excessive iron. Certain agents are also needed for the improvement of stress erythropoiesis and iron dysregulation. Green tea extract (GTE), which is rich in epigallocatechin-3-gallate (EGCG), is known to possess radical scavenging and iron-chelating activities. We aimed to assess the effects of green tea extract on erythroid regulators, iron mobilization and anti-lipid peroxidation in the liver, spleen, and kidneys of iron-loaded β-globin gene knockout thalassemic (BKO) mice. Our results indicate that treatments of green tea extract and/or deferiprone (DFP) diminished levels of plasma erythropoietin (EPO) and erythroferrone (ERFE), and consistently suppressed kidney Epo and spleen Erfe mRNA expressions (p < .05) in iron- loaded BKO mice when compared with untreated mice. Coincidently, the treatments decreased plasma ferritin (Ft) levels, iron content levels in the liver (p < .05), spleen (p < .05), and kidney tissues of iron-loaded BKO mice. Furthermore, lipid-peroxidation products in the tissues and plasma were also decreased when compared with untreated mice. This is the first evidence of the orchestral role of green tea extract abundant with epigallocatechin-3-gallate in improving ineffective erythropoiesis, iron dysregulation and oxidative stress in iron-overloaded β-thalassemic mice.

Generation of human induced pluripotent stem cell line (MUi034-A) from an unusual case of hydrops fetalis associated with homozygous hemoglobin Constant Spring

Hemoglobin Constant Spring (HbCS) is unstable hemoglobin resulting from a nucleotide substitution at the termination codon of the HBA2 gene (c.427 T > C). The homozygous state for HbCS is non-transfusion dependent in adults. Nevertheless, severe anemia is often observed in fetuses. Here, human induced pluripotent stem cell line MUi034-A was generated from peripheral blood CD34+ hematopoietic stem/progenitor cells (HSPCs) derived from a 14-year-old female with homozygous HbCS who had a history of severe anemia and hydrops during fetal period. The MUi034-A cell line represented embryonic-like characteristics as they expressed specific pluripotency markers, differentiated into the three germ layers, and retained normal karyotyping.

Effect of neonatal reticulocytosis on glucose 6-phosphate dehydrogenase (G6PD) activity and G6PD deficiency detection: a cross-sectional study

BACKGROUND

Screening for G6PD deficiency in newborns can help prevent severe hemolysis, hyperbilirubinemia, and bilirubin encephalopathy, as recommended by the World Health Organization (WHO). It has been speculated that the presence of a high number of reticulocytes in newborns interferes with the diagnosis of G6PD deficiency since reticulocytes contain higher amounts of G6PD enzyme than mature erythrocytes. Therefore, the purposes of this study were to assess the effect of reticulocytosis in the determination of blood G6PD activity in Thai newborns by using a novel automated UV-based enzymatic assay and to validate the performance of this assay for the detection of G6PD deficiency in newborn samples.

METHODS

The levels of reticulocytes and G6PD activity were measured in blood samples collected from 1,015 newborns. G6PD mutations were identified using TaqMan^® SNP genotyping assay, PCR-restriction fragment length polymorphism (PCR-RFLP), and direct sequencing. The correlation between the levels of reticulocytes and G6PD activity was examined. The performance of the automated method was compared with that of the fluorescent spot test (FST) and the standard quantitative assay.

RESULTS

The automated assay detected G6PD deficiency in 6.5% of the total newborn subjects compared to 5.3% and 6.1% by the FST and the standard method, respectively. The minor allele frequencies (MAFs) of G6PD Viangchan^G871A, G6PD Mahidol^G487A, and G6PD Union^C1360T were 0.066, 0.005, and 0.005, respectively. The reticulocyte counts in newborns with G6PD deficiency were significantly higher than those in normal male newborns (p < 0.001). Compared with normal newborns after controlling for thalassemias and hemoglobinopathies, G6PD-deficient patients with the G6PD Viangchan^G871A mutation exhibited elevated reticulocyte counts (5.82 ± 1.73%, p < 0.001). In a group of G6PD normal newborns, the percentage of reticulocytes was positively correlated with G6PD activity (r = 0.327, p < 0.001). However, there was no correlation between G6PD activity and the levels of reticulocytes in subjects with G6PD deficiency (r = -0.019, p = 0.881). The level of agreement in the detection of G6PD deficiency was 0.999, while the area under the receiver operating characteristic (AUC) curve demonstrated that the automated method had 98.4% sensitivity, 99.5% specificity, 92.4% positive predictive value (PPV), 99.9% negative predictive value (NPV), and 99.4% accuracy.

CONCLUSIONS

We report that reticulocytosis does not have a statistically significant effect on the detection of G6PD deficiency in newborns by both qualitative and quantitative methods.

Increased autophagy leads to decreased apoptosis during β-thalassaemic mouse and patient erythropoiesis

β-Thalassaemia results from defects in β-globin chain production, leading to ineffective erythropoiesis and subsequently to severe anaemia and other complications. Apoptosis and autophagy are the main pathways that regulate the balance between cell survival and cell death in response to diverse cellular stresses. Herein, the death of erythroid lineage cells in the bone marrow from both β^IVS2-654-thalassaemic mice and β-thalassaemia/HbE patients was investigated. Phosphatidylserine (PS)-bearing basophilic erythroblasts and polychromatophilic erythroblasts were significantly increased in β-thalassaemia as compared to controls. However, the activation of caspase 8, caspase 9 and caspase 3 was minimal and not different from control in both murine and human thalassaemic erythroblasts. Interestingly, bone marrow erythroblasts from both β-thalassaemic mice and β-thalassaemia/HbE patients had significantly increased autophagy as shown by increased autophagosomes and increased co-localization between LC3 and LAMP-1. Inhibition of autophagy by chloroquine caused significantly increased erythroblast apoptosis. We have demonstrated increased autophagy which led to minimal apoptosis in β-thalassaemic erythroblasts. However, increased PS exposure occurring through other mechanisms in thalassaemic erythroblasts might cause rapid phagocytic removal by macrophages and consequently ineffective erythropoiesis in β-thalassaemia.

Deferiprone has less benefits on gut microbiota and metabolites in high iron-diet induced iron overload thalassemic mice than in iron overload wild-type mice: A preclinical study

AIMS

This study aimed to investigate the changes in gut microbiota in iron-overload thalassemia and the roles of an iron chelator on gut dysbiosis/inflammation, and metabolites, including short-chain fatty acids (SCFAs) and trimethylamine N-oxide (TMAO).

MAIN METHODS

Adult male C57BL/6 mice both wild-type (WT: n = 15) and heterozygous β-thalassemia (BKO: n = 15) were fed on either a normal (ND: n = 5/group) or a high‑iron diet for four months (HFe: n = 10/group). HFe-treated WT and HFe-treated BKO groups were further subdivided into two subgroups and each subgroup given either vehicle (n = 5/subgroup) or deferiprone (n = 5/subgroup) during the last month. Gut microbiota profiles, gut barrier characteristics, levels of proinflammatory cytokines, and plasma SCFAs and TMAO were determined at the end of the study.

KEY FINDINGS

HFe-fed WT mice showed distinct gut microbiota profiles from those of ND-fed WT mice, whereas HFe-fed BKO mice showed slightly different gut microbiota profiles from ND-fed BKO. Gut inflammation and barrier disruption were found only in HFe-fed BKO mice, however, an increase in plasma TMAO levels and decreased levels of SCFAs were observed in both WT and BKO mice with HFe-feeding. Treatment with deferiprone, gut dysbiosis and disturbance of metabolites were attenuated in HFe-fed WT mice, but not in HFe-fed BKO mice. Increased Verrucomicrobia and Ruminococcaceae were associated with the beneficial effects of deferiprone.

SIGNIFICANCE

Iron-overload leads to gut dysbiosis/inflammation and disturbance of metabolites, and deferiprone alleviates those conditions more effectively in WT than in those that are thalassemic.

Genetic predictions of life expectancy in southern Thai patients with β0‑thalassemia/Hb E

The types of β-thalassemia mutations, α-thalassemia interactions, and Hb F-associated SNPs have been described in association with variable disease phenotypes. This study aimed to determine the updated spectrum of β-thalassemia mutations and evaluate the contribution of primary and secondary genetic modifiers and SNPs to disease severity, age at onset, and predicted life expectancy in southern Thai β-thalassemia patients. A total of 181 β-thalassemia patients were enrolled and 135 β⁰-thalassemia/Hb E patients without α-thalassemia interactions were divided into three categories according to disease severity, age at onset, and predicted life expectancy. A total of 16 β-thalassemia mutations were identified in this study, and the three most common β-thalassemia mutations accounted for 61.4% of all mutations. It was also found that the XmnI polymorphism and rs2071348 were associated with age at onset and the predicted life expectancy. More than 82% of β⁰-thalassemia/Hb E patients with CC genotype (XmnI) were 3 years old or younger at onset. Additionally, >90% of the higher predicted life expectancy in β⁰-thalassemia/Hb E patients had the T allele of XmnI. Therefore, genetic prediction for age at onset and life expectancy is beneficial and practical during prenatal diagnosis or newborn screening for better genetic counseling and optimal management.

Global Globin Network Consensus Paper: Classification and Stratified Roadmaps for Improved Thalassaemia Care and Prevention in 32 Countries

The Global Globin Network (GGN) is a project-wide initiative of the Human Variome/Global Variome Project (HVP) focusing on haemoglobinopathies to build the capacity for genomic diagnosis, clinical services, and research in low- and middle-income countries. At present, there is no framework to evaluate the improvement of care, treatment, and prevention of thalassaemia and other haemoglobinopathies globally, despite thalassaemia being one of the most common monogenic diseases worldwide. Here, we propose a universally applicable system for evaluating and grouping countries based on qualitative indicators according to the quality of care, treatment, and prevention of haemoglobinopathies. We also apply this system to GGN countries as proof of principle. To this end, qualitative indicators were extracted from the IthaMaps database of the ITHANET portal, which allowed four groups of countries (A, B, C, and D) to be defined based on major qualitative indicators, supported by minor qualitative indicators for countries with limited resource settings and by the overall haemoglobinopathy carrier frequency for the target countries of immigration. The proposed rubrics and accumulative scores will help analyse the performance and improvement of care, treatment, and prevention of haemoglobinopathies in the GGN and beyond. Our proposed criteria complement future data collection from GGN countries to help monitor the quality of services for haemoglobinopathies, provide ongoing estimates for services and epidemiology in GGN countries, and note the contribution of the GGN to a local and global reduction of disease burden.

Impaired Terminal Erythroid Maturation in β0-Thalassemia/HbE Patients with Different Clinical Severity

Anemia in β-thalassemia is associated with ineffective erythropoiesis and a shortened lifespan of erythroid cells. The limited differentiation of β-thalassemic erythroblasts has been documented, but the characteristic feature of terminal erythroid maturation and its physiological relevance are not clearly described in β-thalassemias. Here, the red blood cell and reticulocyte cellular characteristics were determined in patients with β⁰-thalassemia/HbE in comparison to patients with iron deficiency anemia and healthy normal subjects. Severely affected β⁰-thalassemia/HbE patients showed the highest increase in immature reticulocytes, but the number of total erythrocytes was the lowest. Despite similar ranges of hemoglobin levels, β⁰-thalassemia/HbE patients had a higher number of reticulocytes and a greater proportion of immature fraction than patients with iron deficiency anemia did. In vitro CD34⁺ hematopoietic progenitor cells' culture and flow cytometry analysis were conducted to investigate the erythroid maturation and mitochondrial clearance in β⁰-thalassemia/HbE erythroid cells as compared to normal cells. The delayed erythroid maturation and evidence of impaired mitochondria clearance were observed in β⁰-thalassemia/HbE cells at the terminal stage of differentiation. Additionally, increased transcript levels of genes related to erythroid mitophagy, BNIP3L and PINK1, were revealed in β⁰-thalassemia/HbE erythroblasts. The findings indicate that the erythroid maturation is physiologically relevant, and that the restoration of terminal maturation represents a potential therapeutic target for β-thalassemias.

Impaired neutrophil extracellular trap formation in β-thalassaemia/HbE

Neutrophil dysfunction contributes to a high susceptibility to severe bacterial infection which is a leading cause of morbidity and mortality in β-thalassaemia/HbE, especially in splenectomised patients. This study demonstrated another abnormality of neutrophil function, namely neutrophil extracellular trap (NET) formation in splenectomised and non-splenectomised β-thalassaemia/HbE patients who had iron overload. A classification system of morphological NET formation using confocal microscopy was developed, and samples were categorized into early and late phases which were subdivided into web-like and non-web structures. At baseline, neutrophils from non-splenectomised patients (58 ± 4%) and splenectomised patients (65 ± 3%) had higher early phase NETs than those from normal subjects (33 ± 1%). As a mimic of iron overload and infection, haemin/PMA/LPS treatment led to a significant reduction of early NETs and an increase of late NETs in neutrophils from normal and non-splenectomised patients. Interestingly, neutrophils from splenectomised patients had impaired development of late NETs. This suggests that during infection bacteria might not be trapped and may spread from the site of infection resulting in higher susceptibility to severe bacterial infection in splenectomised patients.

Thalassemia in Thailand

Thailand has a population of 66.2 million with 30.0-40.0% of them carrying thalassemia genes. Interaction of these thalassemia genes lead to more than 60 genotypes with a wide spectrum of clinical severity from asymptomatic to lethal. Estimation based on gene frequencies and number of babies born each year, there will be about 1.2% babies born with severe cases of thalassemia each year. Further estimation revealed that 1.0% of the Thai population have thalassemia disease, which is a big health problem for the country. Thalassemia prevention and control programs were introduced using post conception screening in couples and prenatal diagnosis (PND) for the prevention of new thalassemic births. Moreover, the majority of existing cases are undergoing supportive treatment with regular blood transfusions and iron chelation. Curative treatment by hematopoietic stem cell transplantation (HSCT) is available but is limited to a minority of the patients.

Clinical Severity of β-Thalassemia Pediatric Patients in Myanmar

β-Thalassemia (β-thal) is highly prevalent in Myanmar, but limited data are available on the molecular basis and the clinical manifestations in Myanmar patients. In this study, we investigated the clinical features and β-globin gene abnormalities in 15 homozygous β-thal and 60 Hb E (HBB: c.79G>A)/β-thal pediatric patients who attended Yangon Children Hospital, the biggest thalassemia day care unit center in Myanmar. Eight different β⁰-thal mutations were identified, with four accounting for 88.9% of alleles studied (excluding the Hb E variant). A genotype-phenotype correlation was found; all homozygous β⁰-thalassemias had severe clinical courses, whereas the highly variable disease severity was demonstrated among Hb E/β⁰-thal patients. Interactions of IVS-I-1 (G>T) (HBB: c0.92+1G>T) β⁰-thal with Hb E are associated with milder clinical symptoms. The number of mildly affected Hb E/β-thal patients was lower than expected, suggesting that there may be a considerable number of patients in the population who have either not been admitted to hospital or diagnosed with carrying the disease. Although the clinical severity in the Myanmar β-thal patients seems to be similar to that in other populations, the levels of hemoglobin (Hb) appears to be very low. These findings indicate the need for the improvement of patient management and the development of prevention and control programs for β-thal in Myanmar.

Lysine-specific histone demethylase 1 inhibition enhances robust fetal hemoglobin induction in human β0-thalassemia/hemoglobin E erythroid cells

Induction of fetal hemoglobin (HbF) ameliorates the clinical severity of β-thalassemias. Histone methyltransferase LSD1 enzyme removes methyl groups from the activating chromatin mark histone 3 lysine 4 at silenced genes, including the γ-globin genes. LSD1 inhibitor RN-1 induces HbF levels in cultured human erythroid cells. Here, the HbF-inducing activity of RN-1 was investigated in erythroid progenitor cells derived from β⁰-thalassemia/ hemoglobin E (HbE) patients. The significant and reproducible increases in γ-globin transcript and HbF expression upon RN-1 treatment were demonstrated in erythroid cells with divergent HbF baseline levels, the average of HbF induction was 17.7±0.8%. RN-1 at low concentration did not affect viability and proliferation of erythroid cells, but decreases in cell number were observed in cells treated with RN-1 at high concentration. Delayed terminal erythroid differentiation was revealed in β⁰-thalassemia/HbE erythroid cells treated with RN-1 as similar to other compounds that target LSD1 activity. Downregulation of repressors of γ- globin expression; NCOR1 and SOX6, was observed in RN-1 treatment. These findings provide proof of the concept that LSD1 epigenetic enzyme is a potential therapeutic target for β⁰-thalassemia/HbE patients.

Pre-Analytical Modification of Serum miRNAs: Diagnostic Reliability of Serum miRNAs in Hemolytic Diseases

Circulating microRNAs (miRNAs) are useful biomarkers of hemolysis. Since blood cells are the main origins of circulating miRNAs, we evaluated blood cell-related pre-analytical modification of the miRNA signatures during blood drawing and serum processing. The levels of miRNA before and after ex vivo blood drawing were analyzed with the reverse transcriptase-based polymerase chain reaction method. Furthermore, the changes of miRNA signatures caused by different time-lag between blood drawing and serum preparation by 24 h were evaluated. Finally, we compared the miRNA levels between leftover samples and samples of hemolytic diseases. Blood drawing procedure induced increments of red blood cell (RBC)-related miRNAs (miR-451a, miR-486) about 2-fold. One hour standing of blood samples before serum separation induced almost the same increases in RBC-related miRNAs. To test the clinical usefulness of miR-451a as a biomarker of hemolytic diseases, we analyzed miRNAs of samples from 10 normal subjects, 30 leftover samples in the clinical laboratory, and 20 samples from patients with hemolytic diseases. Serum miR-451a significantly increased in patients with hemolytic anemia more than the levels of pre-analytical modification. In conclusion, the pre-analytical modification of serum miRNAs did not disturb the usefulness of RBC-derived miRNAs as biomarkers of hemolytic diseases.

Association of the Degree of Erythroid Expansion and Maturation Arrest with the Clinical Severity of β0-Thalassemia/Hemoglobin E Patients

INTRODUCTION

β-Thalassemia/hemoglobin E represents one-half of all the clinically severe β-thalassemias worldwide. Despite similar genetic backgrounds, patients show clinical heterogeneity ranging from nearly asymptomatic to transfusion-dependent thalassemia. The underlying disease modifying factors remain largely obscure.

METHODS

To elucidate the correlation between ineffective erythropoiesis and β0-thalassemia/hemoglobin E (HbE) disease severity, in vitro culture of erythroid cells derived from patients with different clinical symptoms was established. Cell proliferation, viability, and differentiation were investigated. To identify potential molecular mechanisms leading to the arrested erythroid maturation, the expression levels of erythropoiesis modifying factors were measured.

RESULTS

The β0-thalassemia/HbE cells exhibited enhanced proliferation, limited differentiation, and impaired erythroid terminal maturation but did not show accelerated erythroblast differentiation and increased cell death. Erythroblasts derived from mild patients showed the highest proliferation rate with a faster cell division time, while erythroblasts derived from severe patients displayed extremely delayed erythroid maturation. Downregulation of growth differentiation factor 11 and FOXO3a was observed in mild β0-thalassemia/HbE erythroblasts, while upregulation of heat shock protein 70 and activin receptor 2A was revealed in severe erythroblasts.

DISCUSSION/CONCLUSION

The degree of erythroid expansion and maturation arrest contributes to the severity of β0-thalassemia/HbE patients, accounting for the disease heterogeneity. The findings suggest a restoration of erythroid maturation as a promising targeted therapy for severe patients.

The Origin and Composition of Korean Ethnicity Analyzed by Ancient and Present-Day Genome Sequences

Koreans are thought to be an ethnic group of admixed northern and southern subgroups. However, the exact genetic origins of these two remain unclear. In addition, the past admixture is presumed to have taken place on the Korean peninsula, but there is no genomic scale analysis exploring the origin, composition, admixture, or the past migration of Koreans. Here, 88 Korean genomes compared with 91 other present-day populations showed two major genetic components of East Siberia and Southeast Asia. Additional paleogenomic analysis with 115 ancient genomes from Pleistocene hunter-gatherers to Iron Age farmers showed a gradual admixture of Tianyuan (40 ka) and Devil’s gate (8 ka) ancestries throughout East Asia and East Siberia up until the Neolithic era. Afterward, the current genetic foundation of Koreans may have been established through a rapid admixture with ancient Southern Chinese populations associated with Iron Age Cambodians. We speculate that this admixing trend initially occurred mostly outside the Korean peninsula followed by continuous spread and localization in Korea, corresponding to the general admixture trend of East Asia. Over 70% of extant Korean genetic diversity is explained to be derived from such a recent population expansion and admixture from the South.

Chemical Analysis, Toxicity Study, and Free-Radical Scavenging and Iron-Binding Assays Involving Coffee (Coffea arabica) Extracts

We aimed to analyze the chemical compositions in Arabica coffee bean extracts, assess the relevant antioxidant and iron-chelating activities in coffee extracts and instant coffee, and evaluate the toxicity in roasted coffee. Coffee beans were extracted using boiling, drip-filtered and espresso brewing methods. Certain phenolics were investigated including trigonelline, caffeic acid and their derivatives, gallic acid, epicatechin, chlorogenic acid (CGA) and their derivatives, p-coumaroylquinic acid, p-coumaroyl glucoside, the rutin and syringic acid that exist in green and roasted coffee extracts, along with dimethoxycinnamic acid, caffeoylarbutin and cymaroside that may be present in green coffee bean extracts. Different phytochemicals were also detected in all of the coffee extracts. Roasted coffee extracts and instant coffees exhibited free-radical scavenging properties in a dose-dependent manner, for which drip coffee was observed to be the most effective (p < 0.05). All coffee extracts, instant coffee varieties and CGA could effectively bind ferric ion in a concentration-dependent manner resulting in an iron-bound complex. Roasted coffee extracts were neither toxic to normal mononuclear cells nor breast cancer cells. The findings indicate that phenolics, particularly CGA, could effectively contribute to the iron-chelating and free-radical scavenging properties observed in coffee brews. Thus, coffee may possess high pharmacological value and could be utilized as a health beverage.

Coordinated β-globin expression and α2-globin reduction in a multiplex lentiviral gene therapy vector for β-thalassemia

A primary challenge in lentiviral gene therapy of β-hemoglobinopathies is to maintain low vector copy numbers to avoid genotoxicity while being reliably therapeutic for all genotypes. We designed a high-titer lentiviral vector, LVβ-shα2, that allows coordinated expression of the therapeutic β^A-T87Q-globin gene and of an intron-embedded miR-30-based short hairpin RNA (shRNA) selectively targeting the α2-globin mRNA. Our approach was guided by the knowledge that moderate reduction of α-globin chain synthesis ameliorates disease severity in β-thalassemia. We demonstrate that LVβ-shα2 reduces α2-globin mRNA expression in erythroid cells while keeping α1-globin mRNA levels unchanged and β^A-T87Q-globin gene expression identical to the parent vector. Compared with the first β^A-T87Q-globin lentiviral vector that has received conditional marketing authorization, BB305, LVβ-shα2 shows 1.7-fold greater potency to improve α/β ratios. It may thus result in greater therapeutic efficacy and reliability for the most severe types of β-thalassemia and provide an improved benefit/risk ratio regardless of the β-thalassemia genotype.

The hypoferremic response to acute inflammation is maintained in thalassemia mice even under parenteral iron loading

Background

Hepcidin controls iron homeostasis by inducing the degradation of the iron efflux protein, ferroportin (FPN1), and subsequently reducing serum iron levels. Hepcidin expression is influenced by multiple factors, including iron stores, ineffective erythropoiesis, and inflammation. However, the interactions between these factors under thalassemic condition remain unclear. This study aimed to determine the hypoferremic and transcriptional responses of iron homeostasis to acute inflammatory induction by lipopolysaccharide (LPS) in thalassemic (Hbb^th3/+) mice with/without parenteral iron loading with iron dextran.

Methods

Wild type and Hbb^th3/+ mice were intramuscularly injected with 5 mg of iron dextran once daily for two consecutive days. After a 2-week equilibration, acute inflammation was induced by an intraperitoneal injection of a single dose of 1 µg/g body weight of LPS. Control groups for both iron loading and acute inflammation received equal volume(s) of saline solution. Blood and tissue samples were collected at 6 hours after LPS (or saline) injection. Iron parameters and mRNA expression of hepcidin as well as genes involved in iron transport and metabolism in wild type and Hbb^th3/+ mice were analyzed and compared by Kruskal–Wallis test with pairwise Mann–Whitney U test.

Results

We found the inductive effects of LPS on liver IL-6 mRNA expression to be more pronounced under parenteral iron loading. Upon LPS administration, splenic erythroferrone (ERFE) mRNA levels were reduced only in iron-treated mice, whereas, liver bone morphogenetic protein 6 (BMP6) mRNA levels were decreased under both control and parenteral iron loading conditions. Despite the altered expression of the aforementioned hepcidin regulators, the stimulatory effect of LPS on hepcidin mRNA expression was blunt in iron-treated Hbb^th3/+ mice. Contrary to the blunted hepcidin response, LPS treatment suppressed FPN1 mRNA expression in the liver, spleen, and duodenum, as well as reduced serum iron levels of Hbb^th3/+ mice with parenteral iron loading.

Conclusion

Our study suggests that a hypoferremic response to LPS-induced acute inflammation is maintained in thalassemic mice with parenteral iron loading in a hepcidin-independent manner.

Pathogen-Associated Molecules from Gut Translocation Enhance Severity of Cecal Ligation and Puncture Sepsis in Iron-Overload β-Thalassemia Mice

Introduction

Systemic inflammation induced by gut translocation of lipopolysaccharide (LPS), a major component of Gram-negative bacteria, in thalassemia with iron-overload worsens sepsis. However, the impact of (1→3)-β-D-glucan (BG), a major fungal molecule, in iron-overload thalassemia is still unclear. Hence, the influence of BG was explored in 1) iron-overload mice with sepsis induced by cecal ligation and puncture (CLP) surgery; and 2) in bone marrow-derived macrophages (BMMs).

Methods

The heterozygous β-globin-deficient mice, Hbb^th3/+ mice, were used as representative thalassemia (TH) mice. Iron overload was generated by 6 months of oral iron administration before CLP surgery- induced sepsis in TH mice and wild-type (WT) mice. Additionally, BMMs from both mouse strains were used to explore the impact of BG.

Results

Without sepsis, iron-overload TH mice demonstrated more severe intestinal mucosal injury (gut leakage) with higher LPS and BG in serum, from gut translocation, when compared with WT mice. With CLP in iron-overload mice, sepsis severity in TH mice was more severe than WT as determined by survival analysis, organ injury (kidney and liver), bacteremia, endotoxemia, gut leakage (FITC-dextran) and serum BG. Activation by LPS plus BG (LPS+BG) in BMMs and in peripheral blood-derived neutrophils (both WT and TH cells) demonstrated more prominent cytokine production when compared with LPS activation alone. In parallel, LPS+BG also prominently induced genes expression of M1 macrophage polarization (iNOS, TNF-α and IL-1β) in both WT and TH cells in comparison with LPS activation alone. In addition, LPS+BG activated macrophage cytokine production was enhanced by a high dose of ferric ion (800 mM), more predominantly in TH macrophages compared with WT cells. Moreover, LPS+BG induced higher glycolysis activity with similar respiratory capacity in RAW264.7 (a macrophage cell line) compared with LPS activation alone. These data support an additive pro-inflammatory effect of BG upon LPS.

Conclusion

The enhanced-severity of sepsis in iron-overload TH mice was due to 1) increased LPS and BG in serum from iron-induced gut-mucosal injury; and 2) the pro-inflammatory amplification by ferric ion on LPS+BG activation.

Consumption of a green tea extract-curcumin drink decreases blood urea nitrogen and redox iron in β-thalassemia patients

The most important cause of death in β-thalassemia major patients is organ dysfunction due to iron deposits. Non-transferrin bound iron (NTBI), labile plasma iron (LPI) and labile iron pool are redox-active forms of iron found in thalassemia. Iron chelation therapy is adopted to counteract the resulting iron overload. Extracts of green tea (GTE) and curcumin exhibit iron-chelating and antioxidant activities in iron-loaded cells and β-thalassemic mice. We have used our GTE-CUR drink to investigate the potential amelioration of iron overload and oxidative stress in transfusion-dependent β-thalassemia (TDT) patients. The patients were enrolled for a control group without and with GTE-CUR treatments (17.3 and 35.5 mg EGCG equivalent). Along with regular chelation therapy, they were daily administered the drink for 60 d. Blood samples were collected at the beginning of the study and after 30 d and 60 d for biochemical and hematological tests. Interestingly, we found a decrease of blood urea nitrogen levels (P < 0.05), along with a tendency for a decrease of NTBI and LPI, and a delay in increasing lipid-peroxidation product levels in the GTE-CUR groups. The findings suggest that GTE-CUR could increase kidney function and diminish redox-active iron in iron overloaded β-thalassemia patients.

Genome-Wide Transcriptional Regulation of the Long Non-coding RNA Steroid Receptor RNA Activator in Human Erythroblasts

Erythropoiesis of human hematopoietic stem cells (HSCs) maintains generation of red blood cells throughout life. However, little is known how human erythropoiesis is regulated by long non-coding RNAs (lncRNAs). By using ChIRP-seq, we report here that the lncRNA steroid receptor RNA activator (SRA) occupies chromatin, and co-localizes with CTCF, H3K4me3, and H3K27me3 genome-wide in human erythroblast cell line K562. CTCF binding sites that are also occupied by SRA are enriched for either H3K4me3 or H3K27me3. Transcriptome-wide analyses reveal that SRA facilitates expression of erythroid-associated genes, while repressing leukocyte-associated genes in both K562 and CD36-positive primary human proerythroblasts derived from HSCs. We find that SRA-regulated genes are enriched by both CTCF and SRA bindings. Further, silencing of SRA decreases expression of the erythroid-specific markers TFRC and GYPA, and down-regulates expression of globin genes in both K562 and human proerythroblast cells. Taken together, our findings establish that the lncRNA SRA occupies chromatin, and promotes transcription of erythroid genes, therefore facilitating human erythroid transcriptional program.

Development of DNA controls for detection of β-thalassemia mutations commonly found in Asian

INTRODUCTION

Several DNA-based approaches including a reverse dot-blot hybridization (RDB) have been established for detection of β-thalassemia genotypes to provide accurate genetic counseling and prenatal diagnosis for prevention and control of severe β-thalassemia. However, one of major concerns of these techniques is a risk of misdiagnosis due to a lack of DNA controls. Here, we constructed positive DNA controls for β-thalassemia genotyping in order to ensure that all steps in the analysis are performed properly.

METHODS

Four recombinant β-globin plasmids, including a normal sequence and three different mutant panels covering 10 common β-thalassemia mutations in Asia, were constructed by a conventional cloning method followed by sequential rounds of site-directed mutagenesis. These positive DNA controls were further validated by RDB analysis.

RESULTS

We demonstrated the applicability of established positive DNA controls for β-thalassemia genotyping in terms of accuracy and reproducibility by RDB analysis. We further combined three mutant β-globin plasmids into a single positive control, which showed positive signals for both normal and mutant probes of all tested mutations. Therefore, only two positive DNA controls, normal and combined mutant β-globin plasmids, are required for detecting 10 common β-thalassemia mutations by RDB, reducing the cost, time, and efforts in the routine diagnosis.

CONCLUSION

The β-globin DNA controls established here provide efficient alternatives to a conventional DNA source from peripheral blood, which is more difficult to obtain. They also provide a platform for future development of β-globin plasmid controls with other mutations, which can also be suitable for other DNA-based approaches.

Micromapping of Thalassemia and Hemoglobinopathies Among Laos, Khmer, Suay and Yer Ethnic Groups Residing in Lower Northeastern Thailand

Northeastern (NE) Thailand is one of the areas with a prevalence of thalassemias and hemoglobinopathies. Data on the prevalence of the diseases in minorities in the region has been limited. This study aimed to survey the thalassemias and hemoglobinopathies that take into account ethnicity. Four ethnic groups, including Laos (n = 162), Khmer (n = 145), Suay (n = 134), and Yer (n = 101) inhabiting the lower region of NE Thailand, were selected to represent the study populations. The results demonstrated that an extremely high prevalence of Hb E (HBB: c.79G>A) (>50.0%) was observed in the Khmer, Suay and Yer ethnic groups. The highest prevalence of α⁺-thalassemia (α⁺-thal) [-α^3.7 (rightward)] deletion was found in the Khmer ethnic group (48.28%). The -α^4.2 (leftward) deletion (α⁺-thal) was restricted to the Yer ethnic group. Yer and Suay had a high incidence of Hb Constant Spring (Hb CS; HBA2: c.427T>C) as well as Hb Paksé (HBA2: c.429A>T). As the prevalence of α⁰-thalassemia (α⁰-thal) is relatively high in Suay (7.46%), couples who are members of Suay ethnic population should be urged to undergo hematological screening before planning a pregnancy to control the Hb Bart's hydrops fetalis. Micromapping of thalassemias and hemoglobinopathies herein described will be helpful in genetic counseling and public education campaigns, which should be carried out in appropriate languages, with exhibitions at the village levels. This information will be of benefit for the long-term effort to reduce the burden of severe thalassemia disease in the region.

Genotype-Phenotype Correlation of β-Thalassemia in Malaysian Population: Toward Effective Genetic Counseling

Effective prevention of β-thalassemia (β-thal) requires strategies to detect at-risk couples. This is the first study attempting to assess the prevalence of silent β-thal carriers in the Malaysian population. Hematological and clinical parameters were evaluated in healthy blood donors and patients with β-thal trait, Hb E (HBB: c.79G>A)/β-thal and β-thal major (β-TM). β-Globin gene sequencing was carried out for 52 healthy blood donors, 48 patients with Hb E/β-thal, 34 patients with β-TM and 38 patients with β-thal trait. The prevalence of silent β-thal carrier phenotypes found in 25.0% of healthy Malaysian blood donors indicates the need for clinician's awareness of this type in evaluating β-thal in Malaysia. Patients with β-TM present at a significantly younger age at initial diagnosis and require more blood transfusions compared to those with Hb E/β-thal. The time at which genomic DNA was extracted after blood collection, particularly from patients with β-TM and Hb E/β-thal, was found to be an important determinant of the quality of the results of the β-globin sequencing. Public education and communication campaigns are recommended as apparently healthy individuals have few or no symptoms and normal or borderline hematological parameters. β-Globin gene mutation characterization and screening for silent β-thal carriers in regions prevalent with β-thal are recommended to develop more effective genetic counseling and management of β-thal.

Hemoglobin-bound platelets correlate with the increased platelet activity in hemoglobin E/β-thalassemia

INTRODUCTION

An increase in platelet activity is a contributing factor to vascular complications in hemoglobin E/β-thalassemia (HbE/β-thal). Plasma-free hemoglobin (Hb) increases in HbE/β-thal patients and correlates with platelet activation, but the levels of Hb-bound platelets have never been reported. In this study, we aimed to investigate the levels of Hb-bound platelets and its association with platelet activity in HbE/β-thal patients.

METHODS

Hb-bound platelets were measured by flow cytometry in 22 healthy subjects and 26 HbE/β-thal patients (16 nonsplenectomized and 10 splenectomized HbE/β-thal patients). Plasma Hb was measured by the chemiluminescence method based on the consumption of nitric oxide (NO) by Hb. Expression of P-selectin and activated glycoprotein (aGP) IIb/IIIa on platelets was measured by flow cytometry as a marker of platelet activity.

RESULTS

Both nonsplenectomized and splenectomized HbE/β-thal patients had higher levels of Hb-bound platelets and plasma Hb than healthy subjects. In vitro incubation of dialyzed Hb from patients with platelets of healthy subjects caused an increase in Hb-bound platelets, which was partially inhibited by anti-GPIbα antibody. Plasma Hb positively correlated with Hb-bound platelets. Platelet P-selectin expression at baseline and in response to adenosine diphosphate (ADP, 1 µM) stimulation was higher in nonsplenectomized and splenectomized HbE/β-thal patients than healthy subjects. The ADP-induced aGPIIb/IIIa expression on platelets was also higher in HbE/β-thal patients than healthy subjects. Hb-bound platelets correlated with baseline P-selectin expression and ADP-induced P-selectin expression.

CONCLUSION

HbE/β-thal patients have increased Hb-bound platelets, which is associated with increased baseline platelet activation and reactivity.

Update in Laboratory Diagnosis of Thalassemia

Alpha- and β-thalassemias and abnormal hemoglobin (Hb) are common in tropical countries. These abnormal globin genes in different combinations lead to many thalassemic diseases including three severe thalassemia diseases, i.e., homozygous β-thalassemia, β-thalassemia/Hb E, and Hb Bart’s hydrops fetalis. Laboratory diagnosis of thalassemia requires a number of tests including red blood cell indices and Hb and DNA analyses. Thalassemic red blood cell analysis with an automated hematology analyzer is a primary screening for thalassemia since microcytosis and decreased Hb content of red blood cells are hallmarks of all thalassemic red blood cells. However, these two red blood cell indices cannot discriminate between thalassemia trait and iron deficiency or between α- and β-thalassemic conditions. Today, Hb analysis may be carried out by either automatic high-performance liquid chromatography (HPLC) or capillary zone electrophoresis (CE) system. These two systems give both qualitative and quantitative analysis of Hb components and help to do thalassemia prenatal and postnatal diagnoses within a short period. Both systems have a good correlation, but the interpretation under the CE system should be done with caution because Hb A2 is clearly separated from Hb E. In case of α-thalassemia gene interaction, it can affect the amount of Hb A2/E. Thalassemia genotypes can be characterized by the intensities between alpha-/beta-globin chains or alpha-/beta-mRNA ratios. However, those are presumptive diagnoses. Only DNA analysis can be made for specific thalassemia mutation diagnosis. Various molecular techniques have been used for point mutation detection in β-thalassemia and large-deletion detection in α-thalassemia. All of these techniques have some advantages and disadvantages. Recently, screening for both α- and β-thalassemia genes by next-generation sequencing (NGS) has been introduced. This technique gives an accurate diagnosis of thalassemia that may be misdiagnosed by other conventional techniques. The major limitation for using NGS in the screening of thalassemia is its cost which is still expensive. All service labs highly recommend to select the technique(s) they are most familiar and most economic one for their routine use.

Gut leakage enhances sepsis susceptibility in iron-overloaded β-thalassemia mice through macrophage hyperinflammatory responses

Iron overload induces intestinal-permeability defect (gut leakage), and gut translocation of organismal molecules might enhance systemic inflammation and sepsis severity in patients with thalassemia (Thal). Hence, iron administration in Hbb^th3/+ mice, heterozygous β-globin-deficient Thal mice, was explored. Oral iron administration induced more severe secondary hemochromatosis and gut leakage in Thal mice compared with wild-type (WT) mice. Gut leakage was determined by 1) FITC-dextran assay, 2) spontaneous serum elevation of endotoxin (LPS) and (1→3)-β-d-glucan (BG), molecular structures of gut-organisms, and 3) reduction of tight-junction molecules with increased enterocyte apoptosis (activated caspase-3) by immunofluorescent staining. Iron overload also enhanced serum cytokines and increased Bacteroides spp. (gram-negative bacteria) in feces as analyzed by microbiome analysis. LPS injection in iron-overloaded Thal mice produced higher mortality and prominent cytokine responses. Additionally, stimulation with LPS plus iron in macrophage from Thal mice induced higher cytokines production with lower β-globin gene expression compared with WT. Furthermore, possible gut leakage as determined by elevated LPS or BG (>60 pg/mL) in serum without systemic infection was demonstrated in 18 out of 41 patients with β-thalassemia major. Finally, enhanced LPS-induced cytokine responses of mononuclear cells from these patients compared with cells from healthy volunteers were demonstrated. In conclusion, oral iron administration in Thal mice induced more severe gut leakage and increased fecal gram-negative bacteria, resulting in higher levels of endotoxemia and serum inflammatory cytokines compared with WT. Preexisting hyperinflammatory cytokines in iron-overloaded Thal enhanced susceptibility toward infection.NEW & NOTEWORTHY Although the impact of iron accumulation in several organs of patients with thalassemia is well known, the adverse effect of iron accumulation in gut is not frequently mentioned. Here, we demonstrated iron-induced gut-permeability defect, impact of organismal molecules from gut translocation of, and macrophage functional defect upon the increased sepsis susceptibility in thalassemia mice.

Iron homeostasis in a mouse model of thalassemia intermedia is altered between adolescence and adulthood

Background

Iron overload is one of common complications of β-thalassemia. Systemic iron homeostasis is regulated by iron-regulatory hormone, hepcidin, which inhibits intestinal iron absorption and iron recycling by reticuloendothelial system. In addition, body iron status and requirement can be altered with age. In adolescence, iron requirement is increased due to blood volume expansion and growth spurt. Heterozygous β-globin knockout mice (Hbb^th3/+; BKO) is a mouse model of thalassemia widely used to study iron homeostasis under this pathological condition. However, effects of age on iron homeostasis, particularly the expression of genes involved in hemoglobin metabolism as well as erythroid regulators in the spleen, during adolescence have not been explored in this mouse model.

Methods

Iron parameters as well as the mRNA expression of hepcidin and genes involved in iron transport and metabolism in wildtype (WT) and BKO mice during adolescence (6–7 weeks old) and adulthood (16–20 weeks old) were analyzed and compared by 2-way ANOVA.

Results

The transition of adolescence to adulthood was associated with reductions in duodenal iron transporter mRNA expression and serum iron levels of both WT and BKO mice. Erythrocyte parameters in BKO mice remained abnormal in both age groups despite persistent induction of genes involved in hemoglobin metabolism in the spleen and progressively increased extramedullary erythropiesis. In BKO mice, adulthood was associated with increased liver hepcidin and ferroportin mRNA expression along with splenic erythroferrone mRNA suppression compared to adolescence.

Conclusion

Our results demonstrate that iron homeostasis in a mouse model of thalassemia intermedia is altered between adolescence and adulthood. The present study underscores the importance of the age of thalassemic mice in the study of molecular or pathophysiological changes under thalassemic condition.

Increased ferritin levels in non-transfusion-dependent β°-thalassaemia/HbE are associated with reduced CXCR2 expression and neutrophil migration

Severe bacterial infection is a major complication causing morbidity and mortality in β-thalassaemia/HbE patients. Innate immunity constitutes the first line of defence against bacterial infection. This study aimed to comprehensively investigate the innate immune phenotype and function related to factors predisposing to infection in non-transfusion-dependent (NTD) β°-thalassaemia/HbE patients. Twenty-six patients and 17 healthy subjects were recruited to determine complement activity (C3, C4, mannose-binding lectin and CH50) and surface receptor expression including markers of phagocytosis (CD11b, CD16 and C3bR), inflammation (C5aR) and migration (CD11b, CXCR1 and CXCR2) on neutrophils and monocytes. In addition, phagocytosis and oxidative burst activity of neutrophils and monocytes against Escherichia coli and neutrophil migration were examined. Decreased C3 and surface expression of CD11b and C3bR on neutrophils were found in patients. However, phagocytosis of neutrophils in patients was still in the normal range. Interestingly, patients displayed a significant reduction of surface expression of CXCR2 [1705 ± 217 mean fluorescent intensity (MFI)] on neutrophils, leading to impaired neutrophil migration (9·2 ± 7·7%) when compared to neutrophils from healthy subjects (2261 ± 627 MFI and 27·8 ± 9% respectively). Moreover, surface expression of CXCR2 on neutrophils was associated with splenectomy status, serum ferritin and haemoglobin levels. Therefore, impaired neutrophil migration could contribute to the increased susceptibility to infection seen in NTD β°-thalassaemia/HbE patients.

Deferiprone and efonidipine mitigated iron-overload induced neurotoxicity in wild-type and thalassemic mice

AIMS

We previously demonstrated that iron-overload in non-thalassemic rats induced neurotoxicity and cognitive decline. However, the effect of iron-overload on the brain of thalassemic condition has never been investigated. An iron chelator (deferiprone) provides neuroprotective effects against metal toxicity. Furthermore, a T-type calcium channels blocker (efonidipine) effectively attenuates cardiac dysfunction in thalassemic mice with iron-overload. However, the effects of both drugs on brain of iron-overload thalassemia has not been determined. We hypothesize that iron-overload induces neurotoxicity in Thalassemic and wild-type mice, and not only deferiprone, but also efonidipine, provides neuroprotection against iron-overload condition.

MAIN METHODS

Mice from both wild-type (WT) and β-thalassemic type (HT) groups were assigned to be fed with a standard-diet or high-iron diet containing 0.2% ferrocene/kg of diet (HFe) for 4 months consecutively. After three months of HFe, 75-mg/kg/d deferiprone or 4-mg/kg/d efonidipine were administered to the HFe-fed WT and HT mice for 1 month.

KEY FINDINGS

HFe consumption caused an equal impact on circulating iron-overload, oxidative stress, and inflammation in WT and HT mice. Brain iron-overload and iron-mediated neurotoxicity, such as oxidative stress, inflammation, glial activation, mitochondrial dysfunction, and Alzheimer's like pathologies, were observed to an equal degree in HFe fed WT and HT mice. These pathological conditions were mitigated by both deferiprone and efonidipine.

SIGNIFICANCE

These findings indicate that iron-overload itself caused neurotoxicity, and T-type calcium channels may play a role in this condition.

Impact of the detection of ζ-globin chains and hemoglobin Bart's using immunochromatographic strip tests for α0-thalassemia (--SEA) differential diagnosis

α⁰-Thalassemia is an inherited hematological disorder caused by the deletion of α-globin genes. The Southeast Asian deletion (--^SEA) is the most common type of α⁰-thalassemia observed in Southeast Asian countries. Regarding WHO health policy, an effective α⁰-thalassemia screening strategy is needed to control new severe α-thalassemia cases. In this study, a monoclonal antibody panel was used to develop immunochromatographic (IC) strip tests for detecting the Hb Bart’s and ζ-globin chain. Among 195 samples, all α⁰-thalassemia traits (78 α⁰-thalassemia (--^SEA) and 4 α⁰-thalassemia (--^THAI)) had low MCV or MCH values. The sensitivity, specificity, PPV and NPV of the IC strip tests for ζ-globin and Hb Bart’s for screening α⁰-thalassemia (--^SEA) within the low MCV or MCH samples were 100%, 65.2%, 90.7%, 100% and 96.2%, 47.8%, 86.6%, 78.6%, respectively. All 4 α⁰-thalassemia (--^THAI) traits were negative for ζ-globin chains but positive for Hb Bart’s using the IC strip tests. These results led to a α⁰-thalassemia screening being proposed in which blood samples are first evaluated by MCV, MCH and Hb typing. Samples with high MCV and MCH values are excluded for the presence of the α⁰-thalassemia gene. Samples with low MCV or MCH values are assayed using the developed IC strip tests, where only samples testing positive are further assayed for α⁰-thalassemia by PCR. Patients with Hb H, EA Bart’s or EF Bart’s diseases do not need to use this IC strip assay. Thus, in this study, a simple and cost effective α⁰-thalassemia point of care test was developed.

Immunostick Test for Detecting ζ-Globin Chains and Screening of the Southeast Asian α-Thalassemia 1 Deletion

Background

Couples who carry α-thalassemia-1 deletion are at 25% risk of having a fetus with hemoglobin Bart’s hydrops fetalis. Southeast Asian deletion (−-(SEA)) is the most common type of α-thalassemia 1 among Southeast Asian populations. Thus, identification of the (−-(SEA)) α-thalassemia 1 carrier is necessary for controlling severe α-thalassemia in Southeast Asian countries.

Results

Using our generated anti ζ-globin chain monoclonal antibodies (mAbs) clones PL2 and PL3, a simple immunostick test for detecting ζ-globin chain presence in whole blood lysates was developed. The procedure of the developed immunostick test was as follows. The immunostick paddles were coated with 50 μg/mL of mAb PL2 as capture mAb, or other control antibodies. The coated immunostick was dipped into cocktail containing tested hemolysate at dilution of 1:500, 0.25 μg/mL biotin-labeled mAb PL3 and horseradish peroxidase-conjugated streptavidin at dilution of 1:1000. The immunostick was then dipped in precipitating substrate and the presence of ζ-globin chain in the tested sample was observed by the naked eye. Upon validation of the developed immunostick test with various types of thalassemia and normal subjects, 100% sensitivity and 82% specificity for detection of the (−-(SEA)) α-thalassemia-1 carriers were achieved. The mAb pre-coated immunostick can be stored at room temperature for at least 20 weeks.

Conclusion

In this study, a novel simple immunostick test for the screening of (−-(SEA)) α-thalassemia 1 carriers was presented. The developed immunostick test, within a single test, contains both positive and negative internal procedural controls.

miR-144 regulates oxidative stress tolerance of thalassemic erythroid cell via targeting NRF2

Thalassemia has a high prevalence in Thailand. Oxidative damage to erythroid cells is known to be one of the major etiologies in thalassemia pathophysiology. Oxidative stress status of thalassemia is potentiated by the heme, nonheme iron, and free iron resulting from imbalanced globin synthesis. In addition, levels of antioxidant proteins are reduced in α-thalassemia and β-thalassemia erythrocytes. However, the primary molecular mechanism for this phenotype remains unknown. Our study showed a high expression of miR-144 in β- and α-thalassemia. An increased miR-144 expression leads to decreased expression of nuclear factor erythroid 2-related factor 2 (NRF2) target, especially in α-thalassemia. In α-thalassemia, miR-144 and NRF2 target are associated with glutathione level and anemia severity. To study the effect of miR-144 expression, the gain-loss of miR-144 expression was performed by miR inhibitor and mimic transfection in the erythroblastic cell line. This study reveals that miR-144 expression was upregulated, whereas NRF2 expression and glutathione levels were decreased in comparison with the untreated condition after miR mimic transfection, while the reduction of miR-144 expression contributed to the increased NRF2 expression and glutathione level compared with the untreated condition after miR inhibitor transfection. Moreover, miR-144 overexpression leads to significantly increased sensitivity to oxidative stress at indicated concentrations of hydrogen peroxide (H₂O₂) and rescued by miR-144 inhibitor. Taken together, our findings suggest that dysregulation of miR-144 may play a role in the reduced ability of erythrocyte to deal with oxidative stress and increased RBC hemolysis susceptibility especially in thalassemia.

Neglected Tropical Diseases: The Potential Application of microRNAs for Monitoring NTDs in the Real World

Neglected Tropical Diseases (NTDs) are a common health problem and require an efficient campaign to be eradicated from tropical countries. Almost a million people die of NTDs every year in the world, and almost forty percent of the patients are under 20 years. Mass Drug Administration (MDA) is an effective tool for eradication of this health condition. However, a monitoring system is required to evaluate treatment-response and early detection of the re-emerging NTD. The relevance of current tests depends on good quality of the specimen. Thus, new molecular methods with high sensitivity and specificity are required. In this review, we focus on microRNAs (miRNAs) as biomarkers of NTDs through a narrative review on human research. We searched for reliable search engines using a systematical literature review algorithm and included studies that fit the criterion. Five NTDs (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiases, and trachoma) were set as our target diseases. Later on, the data were extracted and classified as monitoring response and early detection. Four miRNAs were studied in filariasis as a monitoring response. There were 12 miRNAs related to onchocerciasis infection, and 6 miRNAs with schistosomiasis infection. Six miRNAs showed a link to soil-transmitted helminths. Only 3 miRNAs correlated with trachoma infection. In conclusion, circulating miR is a less invasive and promising approach to evaluate NTDs. Further field study may translate those candidate miRs to clinical application of the prevention and control of NTDs.

MRI imaging and histopathological study of brain iron overload of β-thalassemic mice

Brain iron overload is chronic and slow progressing and plays an important role in the pathogenesis of neurodegenerative disorders. Magnetic resonance imaging (MRI) is a useful noninvasive tool for determining liver iron content, but it has not been proven to be adequate for evaluating brain iron overload. We evaluated the usefulness of MRI-derived parameters to determine brain iron concentration in β-thalassemic mice and the effects of the membrane permeable iron chelator, deferiprone. Sixteen β-thalassemic mice underwent 1.5T MRI of the brain that included a multiecho T2*-weighted sequence. Brain T2* values ranged from 28 to 31ms for thalassemic mice. For the iron overloaded thalassemic mice, brain T2* values decreased, ranging from 8 to 12ms, which correlated with the iron overload status of the animals. In addition, brain T2* values increased in the group with the treatment of deferiprone, ranging from 18 to 24ms. Our results may be useful to understand brain pathology in iron overload. Moreover, data could lead to an earlier diagnosis, assist in following disease progression, and demonstrate the benefits of iron chelation therapy.

Restoration of correct βIVS2-654-globin mRNA splicing and HbA production by engineered U7 snRNA in β-thalassaemia/HbE erythroid cells

A cytosine to thymine mutation at nucleotide 654 of human β-globin intron 2 (β^IVS2-654) is one of the most common mutations causing β-thalassaemia in Chinese and Southeast Asians. This mutation results in aberrant β-globin pre-mRNA splicing and prevents synthesis of β-globin protein. Splicing correction using synthetic splice-switching oligonucleotides (SSOs) has been shown to restore expression of the β-globin protein, but to maintain therapeutically relevant levels of β-globin it would require lifelong administration. Here, we demonstrate long-term splicing correction using U7 snRNA lentiviral vectors engineered to target several pre-mRNA splicing elements on the β^IVS2-654-globin pre-mRNA such as cryptic 3' splice site, aberrant 5' splice site, cryptic branch point and an exonic splicing enhancer. A double-target engineered U7 snRNAs targeted to the cryptic branch point and an exonic splicing enhancer, U7.BP + 623, was the most effective in a model cell line, HeLa IVS2-654. Moreover, the therapeutic potential of the vector was demonstrated in erythroid progenitor cells derived from β^IVS2-654-thalassaemia/HbE patients, which showed restoration of correctly spliced β-globin mRNA and led to haemoglobin A synthesis, and consequently improved thalassaemic erythroid cell pathology. These results demonstrate proof of concept of using the engineered U7 snRNA lentiviral vector for treatment of β-thalassaemia.