Molecular therapies in beta-thalassaemia

Maximizing longevity: erythropoietin's impact on sickle cell anaemia survival rates

Sickle cell anaemia (SCA) stands as a hereditary blood disorder characterized by mutated haemoglobin, causing red blood cells to adopt a sickle shape, leading to complications like vaso-occlusive crises, anaemia, and organ damage. Despite advancements in treatment, managing SCA remains challenging, with limited options to increase life expectancy and improve quality of life for affected individuals. This paper reviews the potential impact of erythropoietin (EPO) therapy in enhancing life expectancy and ameliorating complications in individuals with SCA. EPO, primarily recognized for its role in stimulating red blood cell production, holds promise in mitigating anaemia, reducing transfusion dependence, and possibly diminishing the frequency and severity of vaso-occlusive crises in SCA patients. Moreover, by stimulating red blood cell production, EPO therapy might alleviate the vaso-occlusive process, thus reducing the frequency of painful crises and associated complications. Additionally, considering the potential side effects and the need for continuous monitoring, the use of EPO in SCA treatment requires cautious consideration. The potential of EPO therapy in SCA offers a glimpse into novel strategies aimed at improving the quality of life and extending the life expectancy of affected individuals. In conclusion, while the application of EPO in SCA treatment holds promise, additional research is indispensable to comprehend its precise role, optimize dosing strategies, and ensure safety, thereby paving the way for enhanced life expectancy and improved outcomes for individuals living with SCA.

Essential genetic modifiers and their measurable impact in a community-recruited population analysis for non-severe hemoglobin E/β-thalassemia prenatal genetic counseling

The study aimed to identify essential phenotype-modulating factors among the pre-existence of several important ones and clarify their measurable impact on the clinical severity of hemoglobin (Hb) E/β-thalassemia in a community-recruited population analysis. This prospective study was designed to compare modifiers between community- (less or no symptoms) and hospital-recruited individuals with Hb E/β-thalassemia. The formerly included couples previously assessed for prenatal thalassemia at-risk status at 42 community and 7 referral hospitals in Thailand through on-site investigations between June 2020 and December 2021. The control included Hb E/β-thalassemia patients undergoing transfusions. The Mahidol score classified disease severity. Beta-globin, α0-thalassemia (-SEA, -THAI), α+-thalassemia (-α3.7, -α4.2), Hb Constant Spring (αCS) alleles, rs766432 in BCL11A, rs9399137 in HBS1L-MYB, and rs7482144-XmnI were evaluated. Modifiers were compared between 102 community- and 104 hospital-recruited cases. Alleles of β+, -SEA, -α3.7, αCS, and a minor allele of rs9399137 were prevalent in the community and mild severity groups (p < 0.05). Multiple linear regression analysis associated modulating alleles with -4.299 (-SEA), -3.654 (β+), -3.065 (rs9399137, C/C), -2.888 (αCS), -2.623 (-α3.7), -2.361 (rs7482144, A/A), -1.258 (rs9399137, C/T), and -1.174 (rs7482144, A/G) severity score reductions (p < 0.05). Certain modifiers must be considered in routine prenatal genetic counseling for Hb E/β-thalassemia.

Prevalence and genetic analysis of triplicated α-globin gene in Ganzhou region using high-throughput sequencing

α-globin gene triplication carriers were not anemic in general, while some studies found that α-globin gene triplication coinherited with heterozygous β-thalassemia may cause adverse clinical symptoms, which yet lacks sufficient evidence in large populations. In this study, we investigated the prevalence and distribution of α-globin gene triplication as well as the phenotypic characteristics of α-globin gene triplication coinherited with heterozygous β-thalassemia in Ganzhou city, southern China. During 2021-2022, a total of 73,967 random individuals who received routine health examinations before marriage were genotyped for globin gene mutations by high-throughput sequencing. Among them, 1,443 were α-globin gene triplication carriers, with a carrier rate of 1.95%. The most prevalent mutation was αααanti3.7/αα (43.10%), followed by αααanti4.2/αα (38.12%). 42 individuals had coinherited α-globin gene triplication and heterozygous β-thalassemia. However, they did not differ from the individuals with heterozygous β-thalassemia and normal α-globin (αα/αα) in terms of mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) levels. In addition, heterogenous clinical phenotypes were found in two individuals with the same genotype. Our study established a database of Ganzhou α-globin gene triplication and provided practical advice for the clinical diagnosis of α-globin gene triplication.

Prime Editor 3 Mediated Beta-Thalassemia Mutations of the HBB Gene in Human Erythroid Progenitor Cells

Recently developed Prime Editor 3 (PE3) has been implemented to induce genome editing in various cell types but has not been proven in human hematopoietic stem and progenitor cells. Using PE3, we successfully installed the beta-thalassemia (beta-thal) mutations in the HBB gene in the erythroid progenitor cell line HUDEP-2. We inserted the mCherry reporter gene cassette into editing plasmids, each including the prime editing guide RNA (pegRNA) and nick sgRNA. The plasmids were electroporated into HUDEP-2 cells, and the PE3 modified cells were identified by mCherry expression and collected using fluorescence-activated cell sorting (FACS). Sanger sequencing of the positive cells confirmed that PE3 induced precise beta-thal mutations with editing ratios from 4.55 to 100%. Furthermore, an off-target analysis showed no unintentional edits occurred in the cells. The editing ratios and parameters of pegRNA and nick sgRNA were also analyzed and summarized and will contribute to enhanced PE3 design in future studies. The characterization of the HUDEP-2 beta-thal cells showed typical thalassemia phenotypes, involving ineffective erythropoiesis, abnormal erythroid differentiation, high apoptosis rate, defective alpha-globin colocalization, cell viability deterioration, and ROS resisting deficiency. These HUDEP-2 beta-thal cells could provide ideal models for future beta-thal gene therapy studies.

Studying the some biochemical parameters for thalassemia patients in AL-Najaf province

The current study aims to study some biochemical indicators for thalassemia patients in the Najaf governorate, and the study included 25 patients with major beta thalassemia during the period from November 2019 to February 2020 and their ages ranged between (2 - 65) years and 15 healthy people who arenot He had genetic blood diseases and their ages ranged between (2-65) years. The results of the study showed that there are in some biochemical indicators, as there was a significant increase in the level of the enzyme of liver function  ALT that was the focus in patients 23.74 ± 29.53 U\L and in healthy people it was 4.61 ± 11.67U\L Also, the creatinine concentration patients 9.92 ± 26.08 mmol\L and in healthy was, 68.06 ± 51.54 mmol\L, Except for urea, we notice that there was a decrease in its concentration in patients 0.89 ± 3.96 mmol\L and in healthy was 1.03 ± 2.36 mmol\L, There was an increase in the concentration of iron in the blood in patients 382.05 ±64.37 Umol\L And in healthy was 9.48 ± 61.36 Umol\L, as well as a decrease in the concentration of glucose in patients and an increase in healthy people

Lentiviral globin gene therapy with reduced-intensity conditioning in adults with β-thalassemia: a phase 1 trial

β-Thalassemias are inherited anemias that are caused by the absent or insufficient production of the β chain of hemoglobin. Here we report 6-8-year follow-up of four adult patients with transfusion-dependent β-thalassemia who were infused with autologous CD34+ cells transduced with the TNS9.3.55 lentiviral globin vector after reduced-intensity conditioning (RIC) in a phase 1 clinical trial ( NCT01639690) . Patients were monitored for insertional mutagenesis and the generation of a replication-competent lentivirus (safety and tolerability of the infusion product after RIC-primary endpoint) and engraftment of genetically modified autologous CD34+ cells, expression of the transduced β-globin gene and post-transplant transfusion requirements (efficacy-secondary endpoint). No unexpected safety issues occurred during conditioning and cell product infusion. Hematopoietic gene marking was very stable but low, reducing transfusion requirements in two patients, albeit not achieving transfusion independence. Our findings suggest that non-myeloablative conditioning can achieve durable stem cell engraftment but underscore a minimum CD34+ cell transduction requirement for effective therapy. Moderate clonal expansions were associated with integrations near cancer-related genes, suggestive of non-erythroid activity of globin vectors in stem/progenitor cells. These correlative findings highlight the necessity of cautiously monitoring patients harboring globin vectors.

Efficient CRISPR-Cas9-based genome editing of β-globin gene on erythroid cells from homozygous β039-thalassemia patients

Gene editing by the CRISPR-Cas9 nuclease system technology can be considered among the most promising strategies to correct hereditary mutations in a variety of monogenic diseases. In this paper, we present for the first time the correction, by CRISPR-Cas9 gene editing, of the β039-thalassemia mutation, one of the most frequent in the Mediterranean area. The results obtained demonstrated the presence of normal β-globin genes after CRISPR-Cas9 correction of the β039-thalassemia mutation performed on erythroid precursor cells from homozygous β039-thalassemia patients. This was demonstrated by allele-specific PCR and sequencing. Accumulation of corrected β-globin mRNA and relevant "de novo" production of β-globin and adult hemoglobin (HbA) were found with high efficiency. The CRISPR-Cas9-forced HbA production levels were associated with a significant reduction of the excess of free α-globin chains. Genomic toxicity of the editing procedure (low indels and no off-targeting) was analyzed. The protocol might be the starting point for the development of an efficient editing of CD34+ cells derived from β039 patients and for the design of combined treatments using, together with the CRISPR-Cas9 editing of the β-globin gene, other therapeutic approaches, such as, for instance, induction of HbA and/or fetal hemoglobin (HbF) using chemical inducers.

Pregnancy and Childbirth: An Unexpected Cakewalk for a Mother With Beta Thalassemia Major Homozygous for IVS (G-C) Mutation

The thalassemias are the most common single-gene disorders of hemoglobin synthesis. The salient features of beta thalassemia major, in which both alleles of the HBB gene are affected, are transfusion dependency and iron overload. Although with advances in treatment, the life expectancy in such patients has increased, they have difficulty in conceiving. We report a case of pregnancy in a beta thalassemia major patient who was transfusion independent and had no iron overload. Genetic analysis revealed IVS 1-5 (G-C) mutation in the homozygous state which usually manifests in severe disease and blood transfusion dependency. On the contrary, she did not need blood transfusion, had a smooth antenatal period and a vaginal delivery at term with a favorable childbirth experience. This case report highlights complex genetic interplay and the role of fetal hemoglobin (HbF) enhancer loci which modulates HbF levels thereby raising total hemoglobin levels.

Development of the Next Generation Sequencing-Based Diagnostic Test for β-Thalassemia and its Validation in a Pashtun Family

β-Thalassemia (β-thal) is a common monogenic disease with ethnic-specific mutations on the HBB gene throughout the world. The reported mutations either reduce the expression or completely inactivate the HBB gene. In Pakistan, the prevalence of β-thal is high due to consanguineous marriages. Accurate identification of mutations in carriers is imperative for prevention of β-thal in subsequent generations. To overcome the limitations of traditional testing methods for β-thal, a next-generation sequencing (NGS)-based diagnostic test was designed and validated by sequencing the entire HBB gene. The primer set covering the entire HBB gene was designed and validated in a Pashtun β-thalassemic family. The polymerase chain reaction (PCR) product was sequenced using an Illumina MiSeq platform. A homozygous pathogenic insertion of A>AC/AC (rs35699606) was detected in an affected member of the family, while unaffected members were heterozygous for it. In addition, all family members were homozygous for the synonymous variant, A>G/G (rs713040), except the father who was heterozygous for it. We sequenced the entire HBB gene using the NGS-based test, which is highly sensitive, robust and specific for the diagnosis and screening of β-thal in Pakistan, especially for families practicing consanguineous marriages.

HbA1C as a marker of retrograde glycaemic control in diabetes patient with co-existed beta-thalassaemia: A case report and a literature review

WHAT IS KNOWN AND OBJECTIVE

The HbA1C marker used in assessing diabetes control quality is not sufficient in diabetes patients with thalassaemia.

CASE DESCRIPTION

A male diabetic patient with thalassaemia was hospitalized due to distal neuropathic pain, right toe trophic ulcer, unacceptable five-point glycaemic profile and recommended HbA1C value. After simultaneously initiated insulin therapy and management of ulcer by hyperbaric oxygen, the patient showed improved glycaemic control and ulcer healing, which led to the patient's discharge.

WHAT IS NEW AND CONCLUSION

In thalassaemia and haemoglobinopathies, due to discrepancies in the five-point glycaemic profile and HbA1C values, it is necessary to measure HbA1C with a different method or to determine HbA1C and fructosamine simultaneously.

Gene Therapy for Beta-Hemoglobinopathies: Milestones, New Therapies and Challenges

Inherited monogenic disorders such as beta-hemoglobinopathies (BH) are fitting candidates for treatment via gene therapy by gene transfer or gene editing. The reported safety and efficacy of lentiviral vectors in preclinical studies have led to the development of several clinical trials for the addition of a functional beta-globin gene. Across trials, dozens of transfusion-dependent patients with sickle cell disease (SCD) and transfusion-dependent beta-thalassemia (TDT) have been treated via gene therapy and have achieved reduced transfusion requirements. While overall results are encouraging, the outcomes appear to be strongly influenced by the level of lentiviral integration in transduced cells after engraftment, as well as the underlying genotype resulting in thalassemia. In addition, the method of procurement of hematopoietic stem cells can affect their quality and thus the outcome of gene therapy both in SCD and TDT. This suggests that new studies aimed at maximizing the number of corrected cells with long-term self-renewal potential are crucial to ensure successful treatment for every patient. Recent advancements in gene transfer and bone marrow transplantation have improved the success of this approach, and the results obtained by using these strategies demonstrated significant improvement of gene transfer outcome in patients. The advent of new gene-editing technologies has suggested additional therapeutic options. These are primarily focused on correcting the defective beta-globin gene or editing the expression of genes or genomic segments that regulate fetal hemoglobin synthesis. In this review, we aim to establish the potential benefits of gene therapy for BH, to summarize the status of the ongoing trials, and to discuss the possible improvement or direction for future treatments.

Oxidative Stress in β-Thalassemia

Cell oxidative status, which represents the balance between oxidants and antioxidants, is involved in normal functions. Under pathological conditions, there is a shift toward the oxidants, leading to oxidative stress, which is cytotoxic, causing oxidation of cellular components that result in cell death and organ damage. Thalassemia is a hereditary hemolytic anemia caused by mutations in globin genes that cause reduced or complete absence of specific globin chains (commonly, α or β). Although oxidative stress is not the primary etiology of thalassemia, it mediates several of its pathologies. The main causes of oxidative stress in thalassemia are the degradation of the unstable hemoglobin and iron overload-both stimulate the production of excess free radicals. The symptoms aggravated by oxidative stress include increased hemolysis, ineffective erythropoiesis and functional failure of vital organs such as the heart and liver. The oxidative status of each patient is affected by multiple internal and external factors, including genetic makeup, health conditions, nutrition, physical activity, age, and the environment (e.g., air pollution, radiation). In addition, oxidative stress is influenced by the clinical manifestations of the disease (unpaired globin chains, iron overload, anemia, etc.). Application of personalized (theranostics) medicine principles, including diagnostic tests for selecting targeted therapy, is therefore important for optimal treatment of the oxidative stress of these patients. We summarize the role of oxidative stress and the current and potential antioxidative therapeutics in β-thalassemia and describe some methodologies, mostly cellular, that might be helpful for application of a theranostics approach to therapy.

Hepatitis E virus prevalence in Egyptian children with transfusion-dependent thalassemia

Hepatitis E virus (HEV) infection is one of the major public health problems in developing countries. HEV can cause chronic infections in immunocompromised individuals e.g. thalassemic patients with increased risk of morbidity and mortality. In addition there is possibility of HEV transmission through blood transfusion. Therefore, the present study aimed to investigate the seroprevalence and risk factors of HEV infection in β-thalassemic children.

Methods

This cross-sectional study was conducted on 140 Egyptian children suffering from β-thalassemia, attending the hematology outpatient clinic from April to October 2016. Serum samples from patients were collected and anti-HEV antibodies; Immunoglobulin G (IgG) and Immunoglobulin M (IgM)

were measured by enzyme-linked immunosorbent assay (ELISA).

Results

The seroprevalence of HEV in β-thalassemic chidren was relatively high (27.15%). Anti-HEV IgG prevalence was 24.29% while that of IgM was 2.86%. There was significant association between HEV infection and age, residence, liver enzymes and amount of blood transfusion per year.

Conclusions

Thalasemic patients are vulnerable to chronicity and increased risk of morbidity and mortality from HEV infection. Frequent assessment of liver enzymes in thalassemic patients to monitor subclinical HEV is recommended. Close monitoring and HEV screening of blood donations should be taken in consideration. Public awareness about HEV endemicity, modes of transmission, and risk hazards especially in high risk group should be done to reduce the disease burden.

A comprehensive review of the prevalence of beta globin gene variations and the co-inheritance of related gene variants in Saudi Arabians with beta-thalassemia

Beta-thalassemia is a genetic disorder that is caused by variations in the beta-hemoglobin (HBB) gene. Saudi Arabia is among the countries most affected bybeta-thalassemia, and this is particularly problematic in the Eastern regions. This review article is an attempt to compile all the reported mutations to facilitate further national-level studies to prepare a Saudi repository of HBB gene variations. In Saudi Arabians, IVSI-5 (G greater than C) and Cd 39 (C greater than T) are the most prevalent HBB gene variations out of 42 variations. The coinheritance of HBB gene variations with ATRX, HBA1, HBA2, HBA12, AHSP, and KLF1 gene variations were observed to be common in the Saudi population. National surveys on the molecular nature of hemoglobinopathies should be set up through collaborations between research centers from various regions to create a well-documented molecular data bank. This data bank can be used to develop a premarital screening program and lead to the best treatment and prevention strategies for beta-thalassemia.

Consensus Predictive Model for Human K562 Cell Growth Inhibition through Enalos Cloud Platform

β-Thalassemia is an inherited hematologic disorder caused by various mutations of the β-globin gene, thus resulting in a significant decrease in adult hemoglobin (HbA) production. An increase in fetal hemoglobin (HbF) levels by drug molecules is considered of great potential in β-thalassemia treatment and is expected to counterbalance the impaired production of HbA. In this work, based on a set of 129 experimentally tested biological inhibitors, we developed and validated a computational model for the prediction of K562 functional inhibition, possibly associated with HbF induction. To facilitate future advancements in the field, we incorporated our model into Enalos Cloud Platform, which enabled online access to our computational scheme (http://enalos.insilicotox.com/K562) through a user-friendly interface. This web service is offered to the wider community to promote in silico drug discovery through fast and reliable predictions.

Pathophysiology and treatment of patients with beta-thalassemia - an update

Thalassemia (thal) is an autosomal recessive, hereditary, chronic hemolytic anemia due to a partial or complete deficiency in the synthesis of α-globin chains (α-thal) or β-globin chains (β-thal) that compose the major adult hemoglobin (α ₂β _2). It is caused by one or more mutations in the corresponding genes. The unpaired globin chains are unstable; they precipitate intracellularly, resulting in hemolysis, premature destruction of red blood cell [RBC] precursors in the bone marrow, and a short life-span of mature RBCs in the circulation. The state of anemia is treated by frequent RBC transfusions. This therapy results in the accumulation of iron (iron overload), a condition that is exacerbated by the breakdown products of hemoglobin (heme and iron) and the increased iron uptake for the chronic accelerated, but ineffective, RBC production. Iron catalyzes the generation of reactive oxygen species, which in excess are toxic, causing damage to vital organs such as the heart and liver and the endocrine system. Herein, we review recent findings regarding the pathophysiology underlying the major symptoms of β-thal and potential therapeutic modalities for the amelioration of its complications, as well as new modalities that may provide a cure for the disease.

An Aγ-globin G->A gene polymorphism associated with β039 thalassemia globin gene and high fetal hemoglobin production

BACKGROUND

Increase of the expression of γ-globin gene and high production of fetal hemoglobin (HbF) in β-thalassemia patients is widely accepted as associated with a milder or even asymptomatic disease. The search for HbF-associated polymorphisms (such as the XmnI, BCL11A and MYB polymorphisms) has recently gained great attention, in order to stratify β-thalassemia patients with respect to expectancy of the first transfusion, need for annual intake of blood, response to HbF inducers (the most studied of which is hydroxyurea).

METHODS

Aγ-globin gene sequencing was performed on genomic DNA isolated from a total of 75 β-thalassemia patients, including 31 β⁰39/β⁰39, 33 β⁰39/β⁺IVSI-110, 9 β⁺IVSI-110/β⁺IVSI-110, one β⁰IVSI-1/β⁺IVSI-6 and one β⁰39/β⁺IVSI-6.

RESULTS

The results show that the rs368698783 polymorphism is present in β-thalassemia patients in the 5'UTR sequence (+25) of the Aγ-globin gene, known to affect the LYAR (human homologue of mouse Ly-1 antibody reactive clone) binding site 5'-GGTTAT-3'. This Aγ(+25 G->A) polymorphism is associated with the Gγ-globin-XmnI polymorphism and both are linked with the β⁰39-globin gene, but not with the β⁺IVSI-110-globin gene. In agreement with the expectation that this mutation alters the LYAR binding activity, we found that the Aγ(+25 G->A) and Gγ-globin-XmnI polymorphisms are associated with high HbF in erythroid precursor cells isolated from β⁰39/β⁰39 thalassemia patients.

CONCLUSIONS

As a potential explanation of our findings, we hypothesize that in β-thalassemia the Gγ-globin-XmnI/Aγ-globin-(G->A) genotype is frequently under genetic linkage with β⁰-thalassemia mutations, but not with the β⁺-thalassemia mutation here studied (i.e. β⁺IVSI-110) and that this genetic combination has been selected within the population of β⁰-thalassemia patients, due to functional association with high HbF. Here we describe the characterization of the rs368698783 (+25 G->A) polymorphism of the Aγ-globin gene associated in β⁰39 thalassemia patients with high HbF in erythroid precursor cells.

Molecular basis of β thalassemia and potential therapeutic targets

The remarkable phenotypic diversity of β thalassemia that range from severe anemia and transfusion-dependency, to a clinically asymptomatic state exemplifies how a spectrum of disease severity can be generated in single gene disorders. While the genetic basis for β thalassemia, and how severity of the anemia could be modified at different levels of its pathophysiology have been well documented, therapy remains largely supportive with bone marrow transplant being the only cure. Identification of the genetic variants modifying fetal hemoglobin (HbF) production in combination with α globin genotype provide some prediction of disease severity for β thalassemia but generation of a personalized genetic risk score to inform prognosis and guide management requires a larger panel of genetic modifiers yet to be discovered. Nonetheless, genetic studies have been successful in characterizing the key variants and pathways involved in HbF regulation, providing new therapeutic targets for HbF reactivation. BCL11A has been established as a quantitative repressor, and progress has been made in manipulating its expression using genomic and gene-editing approaches for therapeutic benefits. Recent discoveries and understanding in the mechanisms associated with ineffective and abnormal erythropoiesis have also provided additional therapeutic targets, a couple of which are currently being tested in clinical trials.

Structural and Functional Insights on an Uncharacterized Aγ-Globin-Gene Polymorphism Present in Four β0-Thalassemia Families with High Fetal Hemoglobin Levels

INTRODUCTION

Several DNA polymorphisms have been associated with high production of fetal hemoglobin (HbF), although the molecular basis is not completely understood. In order to identify and characterize novel HbF-associated elements, we focused on five probands and their four families (from Egypt, Iraq and Iran) with thalassemia major (either β(0)-IVSII-1 or β(0)-IVSI-1) and unusual HbF elevation (>98 %), congenital or acquired after rejection of bone marrow transplantation, suggesting an anticipated favorable genetic background to high HbF expression.

METHODS

Patient recruitment, genomic DNA sequencing, western blotting, electrophoretic mobility shift assays, surface plasmon resonance (SPR) biospecific interaction analysis, bioinformatics analyses based on docking experiments.

RESULTS

A polymorphism of the Aγ-globin gene is here studied in four families with β(0)-thalassemia (β(0)-IVSII-1 and β(0)-IVSI-1) and expressing unusual high HbF levels, congenital or acquired after rejection of bone marrow transplantation. This (G→A) polymorphism is present at position +25 of the Aγ-globin genes, corresponding to a 5'-UTR region of the Aγ-globin mRNA and, when present, is physically linked in chromosomes 11 of all the familiar members studied to the XmnI polymorphism and to the β(0)-thalassemia mutations. The region corresponding to the +25(G→A) polymorphism of the Aγ-globin gene belongs to a sequence recognized by DNA-binding protein complexes, including LYAR (Ly-1 antibody reactive clone), a zinc-finger transcription factor previously proposed to be involved in down-regulation of the expression of γ-globin genes in erythroid cells.

CONCLUSION

We found a novel polymorphism of the Aγ-globin gene in four families with β(0)-thalassemia and high levels of HbF expression. Additionally, we report evidence suggesting that the Aγ-globin gene +25(G→A) polymorphism decreases the efficiency of the interaction between this sequence and specific DNA binding protein complexes.

Evolutionary context for the association of γ-globin, serum uric acid, and hypertension in African Americans

Background

Hyperuricemia and associated cardio-metabolic disorders are more prevalent in African Americans than in European Americans. We used genome-wide admixture mapping and association testing to identify loci with ancestry effects on serum uric acid levels.

Methods

We analyzed 1,976 African Americans from Washington, D.C, including 1,322 individuals from 328 pedigrees and 654 unrelated individuals, enrolled in the Howard University Family Study. We performed admixture mapping and genome-wide association testing using ~800 k autosomal single-nucleotide polymorphisms (SNPs). We performed fine mapping by dense genotyping. We assessed functionality by a combination of bioinformatic annotation, reporter gene assays, and gel shift experiments. We also analyzed 12,641 individuals enrolled in the National Health and Nutrition Examination Survey.

Results

We detected a genome-wide significant locus on chromosome 11p15.4 at which serum uric acid levels increased with increasing African ancestry, independent of kidney function. Fine-mapping identified two independent signals in the β-globin locus. The ancestral allele at SNP rs2855126, located upstream of the hemoglobin, gamma A gene HBG1, was associated with increased serum uric acid levels and higher expression of a reporter gene relative to the derived allele. Hyperuricemia was associated with increased risk of hypertension in 3,767 African Americans (Odds Ratio = 2.48, p = 2.71 × 10^− 19).

Conclusions

Given that increased expression of γ-globin leads to increased levels of fetal hemoglobin which confers protection against malaria, we hypothesize that evolution in Africa of protection against malaria may have occurred at the cost of increased serum uric acid levels, contributing to the high rates of hyperuricemia and associated cardio-metabolic disorders observed in African Americans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0249-z) contains supplementary material, which is available to authorized users.

Serum Bcl-2 Levels in Patients with β-Thalassemia Minor: A Pilot Study

Objective: Anti-apoptotic proteins such as Bcl-2 and Bcl-xL may play a role in the survival of erythroid progenitor cells. Information about these proteins in patients with β-thalassemia minor is limited. We aimed to determine the levels of serum Bcl-2 in patients with β-thalassemia minor.

Materials and Methods: Ninety-seven patients (60 females and 37 males with mean age of 29±21 years) with β-thalassemia minor were enrolled in this study. The diagnosis of β-thalassemia minor was based on whole blood counts, family history, and HbA2 levels estimated by high-performance liquid chromatography. The control group comprised 23 healthy adults (17 females and 6 males with mean age of 58±9 years) without anemia. The levels of serum Bcl-2 were measured by enzyme-linked immunosorbent assay. Mann-Whitney U tests were used in statistical evaluation and p<0.05 was accepted as statistically significant.

Results: Although there was no statistically significant difference between patients with β-thalassemia minor and the control group for the level of serum Bcl-2 (p>0.05), these levels were higher in β-thalassemia minor patients than controls.

Conclusion: There are damaged beta chains in β-thalassemia minor. Therefore, it is expected that premature death of red blood cells may occur due to apoptosis. The mean age of the control group was higher than that of the β-thalassemia minor group; this may be why Bcl-2 levels were higher in the β-thalassemia minor group. It is known that older age constitutes a risk for increased apoptosis. Other proteins (Bad, Bax, etc.) and pathways [CD95 (Fas) ligand] associated with apoptosis should be evaluated in future studies including more patients.

Development and characterization of K562 cell clones expressing BCL11A-XL: Decreased hemoglobin production with fetal hemoglobin inducers and its rescue with mithramycin

Induction of fetal hemoglobin (HbF) is considered a promising strategy in the treatment of β-thalassemia, in which production of adult hemoglobin (HbA) is impaired by mutations affecting the β-globin gene. Recent results indicate that B-cell lymphoma/leukemia 11A (BCL11A) is a major repressor of γ-globin gene expression. Therefore, disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter provides a novel approach for inducing expression of the γ-globin genes. To develop a cellular screening system for the identification of BCL11A inhibitors, we produced K562 cell clones with integrated copies of a BCL11A-XL expressing vector. We characterized 12 K562 clones expressing different levels of BCL11A-XL and found that a clear inverse relationship does exist between the levels of BCL11A-XL and the extent of hemoglobinization induced by a panel of HbF inducers. Using mithramycin as an inducer, we found that this molecule was the only HbF inducer efficient in rescuing the ability to differentiate along the erythroid program, even in K562 cell clones expressing high levels of BCL11A-XL, suggesting that BCL11A-XL activity is counteracted by mithramycin.

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K562 clones were described with integrated copies of a BCL11A-XL expressing vector.

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B-Cell lymphoma/leukemia 11A-XL (BCL11A-XL) levels inversely correlate with the extent of hemoglobin induction.

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Mithramycin induces γ-globin genes even in K562 clones expressing high levels of BCL11A-XL.

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K562(BCL11A-XL) clones might be useful in identifying fetal hemoglobin inducers acting on BCL11A.

Interaction of an α-Globin Gene Triplication with β-Globin Gene Mutations in Iranian Patients with β-Thalassemia Intermedia

The 3.7 kb triplicated α-globin gene (ααα(anti 3.7)) mutation has been found in most populations. It results from an unequal crossover between misaligned homologous segments in the α-globin gene cluster during meiosis. The pathophysiology and clinical severity of β-thalassemia (β-thal) are associated with the degree of α chain imbalance. The excess of α-globin chains plays an important role in the pathophysiology of β-thal. When heterozygous/homozygous β-thal coexists with an α gene numerical alteration, the clinical and hematological phenotype of thalassemia could change to mild anemia in case of an α deletion (-α/αα) or severe anemia in the case of an α triplication (αα/ααα). The coexistence of an ααα(anti 3.7) triplication is considered an important factor in the severity of β-thal, exacerbating the phenotypic severity of β-thal by causing more globin chain imbalance. This study shows that the ααα(anti 3.7) triplication is an important factor in the causation of β-thal intermedia (β-TI) in heterozygous β-thal. This type of phenotype modification has rarely been observed and reported in the Iranian population. Here we report the coinheritance of a triplicated α-globin gene arrangement and heterozygous/homozygous β-thal in 23 cases, presenting with a β-TI or β-thal major (β-TM) phenotype. Some of these patients were considered to have a mild β-TI phenotype as they needed no blood transfusions; some occasionally received blood transfusions in their lifetime (for example on delivery) but some are dependent on regular blood transfusions (every 20 to 40 days). Our study was focused on the importance of detecting the α-globin gene triplication in genotype/phenotype prediction in Iranian thalassemia patients.

Accuracy of Reverse Dot-Blot PCR in Detection of Different β-Globin Gene Mutations

Prevention programs for β-thalassemia based on molecular diagnosis of heterozygous carriers and/or patients require the use of reliable mutation screening methods. The aim of this study was to compare between direct DNA sequencing, and reverse dot-blot PCR in detection of different β-globin gene mutations in Egyptian children with β-thalassemia. Forty children with β-thalassemia were subjected to mutation analysis, performed by both direct DNA sequencing and β-globin Strip Assay MED™ (based on reverse dot-blot PCR). The most frequent mutant alleles detected by reverse dot-blot PCR were; IVSI-110 G>A (31.25 %), IVS I-6 T > C (21.25 %), and IVS I-1 G>A (20 %). Relatively less frequent mutant alleles detected by reverse dot-blot PCR were "IVSII-1 G>A (5 %), IVSII-745 C>G (5 %), IVSII-848 C>A (2.5 %), IVSI-5 G>C (2.5 %), -87 C>G(2.5 %), and cd39 C>T (2.5 %)", While the genotypes of three patients (6 alleles 7.5 %) were not detected by reverse dot-blot PCR. Mutant alleles detected by direct DNA sequencing were the same as reverse dot-blot PCR method except it revealed the genotypes of 3 undetected patients (one patient was homozygous IVSI-110 G>A, and two patients were homozygous IVS I-1 G>A. Sensitivity of the reverse dot-blot PCR was 92.5 % when compared to direct DNA sequencing for detecting β-thalassemia mutations. Our results therefore suggest that, direct DNA sequencing may be preferred over reverse dot-blot PCR in critical diagnostic situations like genetic counseling for prenatal diagnosis.

Recent trends in the gene therapy of β-thalassemia

The β-thalassemias are a group of hereditary hematological diseases caused by over 300 mutations of the adult β-globin gene. Together with sickle cell anemia, thalassemia syndromes are among the most impactful diseases in developing countries, in which the lack of genetic counseling and prenatal diagnosis have contributed to the maintenance of a very high frequency of these genetic diseases in the population. Gene therapy for β-thalassemia has recently seen steadily accelerating progress and has reached a crossroads in its development. Presently, data from past and ongoing clinical trials guide the design of further clinical and preclinical studies based on gene augmentation, while fundamental insights into globin switching and new technology developments have inspired the investigation of novel gene-therapy approaches. Moreover, human erythropoietic stem cells from β-thalassemia patients have been the cellular targets of choice to date whereas future gene-therapy studies might increasingly draw on induced pluripotent stem cells. Herein, we summarize the most significant developments in β-thalassemia gene therapy over the last decade, with a strong emphasis on the most recent findings, for β-thalassemia model systems; for β-, γ-, and anti-sickling β-globin gene addition and combinatorial approaches including the latest results of clinical trials; and for novel approaches, such as transgene-mediated activation of γ-globin and genome editing using designer nucleases.

Recent trends for novel options in experimental biological therapy of β-thalassemia

INTRODUCTION

β-thalassemias are caused by nearly 300 mutations of the β-globin gene, leading to low or absent production of adult hemoglobin. Achievements have been recently obtained on innovative therapeutic strategies for β-thalassemias, based on studies focusing on the transcriptional regulation of the γ-globin genes, epigenetic mechanisms governing erythroid differentiation, gene therapy and genetic correction of the mutations.

AREAS COVERED

The objective of this review is to describe recently published approaches (the review covers the years 2011 - 2014) useful for the development of novel therapeutic strategies for the treatment of β-thalassemia.

EXPERT OPINION

Modification of β-globin gene expression in β-thalassemia cells was achieved by gene therapy (eventually in combination with induction of fetal hemoglobin [HbF]) and correction of the mutated β-globin gene. Based on recent areas of progress in understanding the control of γ-globin gene expression, novel strategies for inducing HbF have been proposed. Furthermore, the identification of microRNAs involved in erythroid differentiation and HbF production opens novel options for developing therapeutic approaches for β-thalassemia and sickle-cell anemia.

Molecular basis of transfusion dependent beta-thalassemia major patients in Sabah

Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of β-thalassemia major patients. Accurate population frequency data of the molecular basis of β-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of β-globin gene defects was done in 252 transfusion dependent β-thalassemia patients incorporating few PCR techniques. The study demonstrates that β-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent β-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino β(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of β-thalassemia major in Sabah.

Combining gene therapy and fetal hemoglobin induction for treatment of β-thalassemia

β-thalassemias are caused by nearly 300 mutations of the β-globin gene, leading to a low or absent production of adult hemoglobin (HbA). Two major therapeutic approaches have recently been proposed: gene therapy and induction of fetal hemoglobin (HbF) with the objective of achieving clinically relevant levels of Hbs. The objective of this article is to describe the development of therapeutic strategies based on a combination of gene therapy and induction of HbFs. An increase of β-globin gene expression in β-thalassemia cells can be achieved by gene therapy, although de novo production of clinically relevant levels of adult Hb may be difficult to obtain. On the other hand, an increased production of HbF is beneficial in β-thalassemia. The combination of gene therapy and HbF induction appears to be a pertinent strategy to achieve clinically relevant results.

Regional consensus opinion for the management of Beta thalassemia major in the Arabian Gulf area

Thalassemia syndrome has diverse clinical presentations and a global spread that has far exceeded the classical Mediterranean basin where the mutations arose. The mutations that give rise to either alpha or beta thalassemia are numerous, resulting in a wide spectrum of clinical severity ranging from carrier state to life-threatening, inherited hemolytic anemia that requires regular blood transfusion. Beta thalassemia major constitutes a remarkable challenge to health care providers. The complications arising due to the anemia, transfusional iron overload, as well as other therapy-related complications add to the complexity of this condition. To produce this consensus opinion manuscript, a PubMed search was performed to gather evidence-based original articles, review articles, as well as published work reflecting the experience of physicians and scientists in the Arabian Gulf region in an effort to standardize the management protocol.

Unique pattern of mutations in β-thalassemia patients in Western Uttar Pradesh

CONTEXT

β-thalassemia is one of the most common heterogeneous inherited single gene disorders. The disease results from one or more of 380 different mutations in the β-globin gene. Uttar Pradesh (U.P.) is the most populous state of India, comprising various ethnic groups and Bareilly is one of the largest cities situated in Western U.P.

AIMS

To examine the prevalence of five common β-thalassemian mutations: Intervening Sequence IVS 1-5 (c. 92 + 5 G > C), codon 8/9 (c. 27_28insG), codon 41/42 (c. 124_127delTTCT), IVS 1-1 (c. 92 + 1 G > T) and codon 26 G-A (c. 79G > A) in Western U.P.

SETTINGS AND DESIGN

Patients attending camps organized by the Thalassemia Society, Bareilly were selected for the study.

MATERIALS AND METHODS

A total of 48 blood samples were collected from the patients of transfusion dependent β-thalassemia from July 2011 to May 2012. All the samples were analyzed for five common mutations by using the Amplification Refractory Mutation System (ARMS)-hot start-polymerase chain reaction (PCR) technique.

RESULTS

Among the five common mutations prevalent in India, we were able to detect all except codon 26 G-A (c. 79G > A), which is prevalent in northeast India. These four mutations accounted for 58% of the total number of our patients. The IVS 1-5 (G-C) was found to be the most common mutation with a frequency of 46% and the 2 (nd)most common mutation was Fr8/9 (+G) with a frequency of 21%. The frequency of other mutations was IVS1-1 (12%) and Cd 41/42 (4%).

CONCLUSION

This study provides evidence that the pattern of mutations in Western U.P. is different from the rest of India and even from the neighboring states (Delhi and Punjab). To the best of our knowledge, mutation Fr8/9, the 2(nd)most common mutation in our study has never been reported to be so common from anywhere in India. Some mutations, which are prevalent in other regions are absent in our region (mutation for ε-globin). Hence, these findings can be called unique to Western U.P.

Plastrum testudinis induces γ-globin gene expression through epigenetic histone modifications within the γ-globin gene promoter via activation of the p38 MAPK signaling pathway

The pharmacologically-induced expression of the γ-globin gene, to increase fetal hemoglobin (HbF) production, is a therapeutic strategy used for the treatment of β-thalassemia and sickle cell anemia (SCA). The aim of this study was to investigate the effects of Plastrum testudinis (PT) on differentiation, proliferation, γ-globin gene expression and HbF synthesis in human erythroid cells. For this purpose, we used the K562 human leukemia cell line and human erythroid progenitor cells from normal donors and patients with β-thalassemia cultured using the two-phase liquid culture system. The effects of PT on erythroid differentiation, proliferation, γ-globin gene expression and HbF synthesis, as well as the involvement of epigenetic histone modifications within the γ-globin gene promoter via activation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway, were assessed by benzidine staining, trypan-blue dye exclusion, quantitative real-time RT-PCR (qRT-PCR), western blot analysis and chromatin immunoprecipitation (ChIP). PT promoted the erythroid differentiation of K562 cells, and increased γ-globin mRNA accumulation and HbF synthesis without inhibiting cell proliferation in K562 cells and human erythroid progenitors. PT exerted no effect on α- and β-globin gene expression. In human erythroid cells, PT activated the p38 MAPK signaling pathway, and enhanced the acetylation of histone H3 and H4, the phosphorylation of histone H3 within the Gγ- and Aγ-globin gene promoter regions, γ-globin mRNA accumulation and HbF synthesis. These effects were suppressed by pre-treatment with the p38 MAPK inhibitor, SB203580. Epigenetic histone modifications within γ-globin gene promoter regions, via activation of the p38 MAPK signaling pathway, are important for the induction of γ-globin gene expression in human erythroid cells by PT. PT may be a novel potential therapeutic agent for β-hemoglobinopathies, including β-thalassemia and SCA.

The potential role of cell penetrating peptides in the intracellular delivery of proteins for therapy of erythroid related disorders

The erythroid related disorders (ERDs) represent a large group of hematological diseases, which in most cases are attributed either to the deficiency or malfunction of biosynthetic enzymes or oxygen transport proteins. Current treatments for these disorders include histo-compatible erythrocyte transfusions or allogeneic hematopoietic stem cell (HSC) transplantation. Gene therapy delivered via suitable viral vectors or genetically modified HSCs have been under way. Protein Transduction Domain (PTD) technology has allowed the production and intracellular delivery of recombinant therapeutic proteins, bearing Cell Penetrating Peptides (CPPs), into a variety of mammalian cells. Remarkable progress in the field of protein transduction leads to the development of novel protein therapeutics (CPP-mediated PTs) for the treatment of monogenetic and/or metabolic disorders. The “concept” developed in this paper is the intracellular protein delivery made possible via the PTD technology as a novel therapeutic intervention for treatment of ERDs. This can be achieved via four stages including: (i) the production of genetically engineered human CPP-mediated PT of interest, since the corresponding native protein either is missing or is mutated in the erythroid progenitor cell (ErPCs) or mature erythrocytes of patients; (ii) isolation of target cells from the peripheral blood of the selected patients; (iii) ex vivo transduction of cells with the CPP-mediated PT of interest; and (iv) re-administration of the successfully transduced cells back into the same patients.

Candidate diseases for prenatal gene therapy

Prenatal gene therapy aims to deliver genes to cells and tissues early in prenatal life, allowing correction of a genetic defect, before irreparable tissue damage has occurred. In contrast to postnatal gene therapy, prenatal application may target genes to a large population of stem cells, and the smaller fetal size allows a higher vector to target cell ratio to be achieved. Early gestation delivery may allow the development of immune tolerance to the transgenic protein, which would facilitate postnatal repeat vector administration if needed. Moreover, early delivery would avoid anti-vector immune responses which are often acquired in postnatal life. The NIH Recombinant DNA Advisory Committee considered that a candidate disease for prenatal gene therapy should pose serious morbidity and mortality risks to the fetus or neonate, and not have any effective postnatal treatment. Prenatal gene therapy would therefore be appropriate for life-threatening disorders, in which prenatal gene delivery maintains a clear advantage over cell transplantation or postnatal gene therapy. If deemed safer and more efficacious, prenatal gene therapy may be applicable for nonlethal conditions if adult gene transfer is unlikely to be of benefit. Many candidate diseases will be inherited congenital disorders such as thalassaemia or lysosomal storage disorders. However, obstetric conditions such as fetal growth restriction may also be treated using a targeted gene therapy approach. In each disease, the condition must be diagnosed prenatally, either via antenatal screening and prenatal diagnosis, for example, in the case of hemophilias, or by ultrasound assessment of the fetus, for example, congenital diaphragmatic hernia. In this chapter, we describe some examples of the candidate diseases and discuss how a prenatal gene therapy approach might work.

Alternative options for DNA-based experimental therapy of β-thalassemia

INTRODUCTION

Beta-thalassemias are caused by more than 200 mutations of the β-globin gene, leading to low or absent production of adult hemoglobin. Achievements have been made with innovative therapeutic strategies for β-thalassemias, based on research conducted at the levels of gene structure, transcription, mRNA processing and protein synthesis.

AREAS COVERED

The objective of this review is to describe the development of therapeutic strategies employing viral and non-viral DNA-based approaches for treatment of β-thalassemia.

EXPERT OPINION

Modification of β-globin gene expression in β-thalassemia cells has been achieved by gene therapy, correction of the mutated β-globin gene and RNA repair. In addition, cellular therapy has been proposed for β-thalassemia, including reprogramming of somatic cells to generate induced pluripotent stem cells to be genetically corrected. Based on the concept that increased production of fetal hemoglobin (HbF) is beneficial in β-thalassemia, DNA-based approaches to increase HbF production have been optimized, including treatment of target cells with lentiviral vectors carrying γ-globin genes. Finally, DNA-based targeting of α-globin gene expression has been applied to reduce the excess of α-globin production by β-thalassemia cells, one of the major causes of the clinical phenotype.

New updating into hemoglobinopathies

Thalassemia and abnormal hemoglobin are the most common genetic disorders and are considered health problems in many developing countries. In the last few years, there has been much progress in laboratory diagnosis, treatment and control of thalassemia. The variation in the clinical severity in both α- and β-thalassemia reflects a genotype-phenotype interaction. This is important for future therapeutic intervention and should be well characterized in each population. The quality of life of the patients is much improved with regular blood transfusion and novel iron chelators. The cure for thalassemia is possible by stem cell transplantation and future gene therapy. It is expected that under multinational collaboration the prevention of thalassemia will happen worldwide.

Organ targeted prenatal gene therapy--how far are we?

Prenatal gene therapy aims to deliver genes to cells and tissues early in prenatal life, allowing correction of a genetic defect, before long-term tissue damage has occurred. In contrast to postnatal gene therapy, prenatal application can target genes to a large population of dividing stem cells, and the smaller fetal size allows a higher vector-to-target cell ratio to be achieved. Early-gestation delivery may allow the development of immune tolerance to the transgenic protein which would facilitate postnatal repeat vector administration if needed. Targeting particular organs will depend on manipulating the vector to achieve selective tropism and on choosing the most appropriate gestational age and injection method for fetal delivery. Intra-amniotic injection reaches the skin, and other organs that are bathed in the fluid however since gene transfer to the lung and gut is usually poor more direct injection methods will be needed. Delivery to the liver and blood can be achieved by systemic delivery via the umbilical vein or peritoneal cavity. Gene transfer to the central nervous system in the fetus is difficult but newer vectors are available that transduce neuronal tissue even after systemic delivery.

Thalassemia: an overview of 50 years of clinical research

The thalassemias are attributable to the defective production of the α- and β-globin polypeptides of hemoglobin. Significant discoveries have illuminated the pathophysiology and enhanced the prevention and treatment of the thalassemias, and this article reviews many of the advances that have occurred in the past 50 years. However, the application of new approaches to the treatment of these disorders has been slow, particularly in the developing world where the diseases are common, but there is definite progress. This article emphasizes how the increasing knowledge of cellular and molecular biology are facilitating the development of more effective therapies for these patients.

Derivation of cloned human blastocysts by histone deacetylase inhibitor treatment after somatic cell nuclear transfer with β-thalassemia fibroblasts

Derivation of embryonic stem cells from patient-specific cloned blastocysts by somatic cell nuclear transfer (SCNT) holds promise for both regenerative medicine and cell-based drug discovery. However, the efficiency of blastocyst formation after human SCNT is very low. The developmental competence of SCNT embryos has been previously demonstrated in several species to be enhanced by treatment with histone deacetylase inhibitors, such as trichostatin A (TSA), to increase histone acetylation. In this study, we report that treatment of SCNT embryos with 5  nM TSA for 10  h following activation incubation increased the developmental competence of human SCNT embryos constructed from β-thalassemia fibroblast cells. The efficiency of blastocyst formation from SCNT human embryos treated with TSA was approximately 2 times greater than that from untreated embryos. Cloned blastocysts were confirmed to be generated through SCNT by DNA and mitochondrial DNA fingerprinting analyses. Further, treatment of SCNT embryos with TSA improved the acetylation of histone H3 at lysine 9 in a manner similar to that observed in in vitro fertilized embryos.

Role of iron deficiency anemia in the propagation of beta thalssemia gene

BACKGROUND

The diagnostic criterion for beta thalassemia trait (BTT) is elevated Hb-A(2) levels. Iron deficiency anemia (IDA) reduces the synthesis of Hb-A(2), resulting in reduced Hb-A(2) levels, so patients with co-pathological conditions BTT with IDA, may have a normal level of Hb-A(2). Many socio-economic factors like unawareness, poor diagnostic facilities, and cost of molecular diagnosis (for screening purposes) result in interpretation of these subjects as normal.

METHODS

Venous blood samples from 200 unmarried females having a family history of thalassemia were collected, and basic hematological parameters, hemoglobin electrophoresis, and molecular analysis for beta thalassemia were done. Patients with IDA and patients with co-pathological conditions BTT and IDA were treated with oral iron. These subjects were then followed for a period of 20 weeks.

RESULTS

Of the 200 females, 34 were found to be anemic. Hemoglobin electrophoresis identified 16 of these patients as BTT. Molecular analysis of all patients confirmed this diagnosis, but identified 8 additional patients with BTT. Eight patients that were not detected with hemoglobin electrophoresis were found to have co-pathology of BTT with IDA.

CONCLUSION

Patients with the co-pathological condition BTT with IDA may be interpreted as being normal, as they have normal Hb-A(2) levels. These misdiagnosed subjects when marry with BTT have the potential to produce beta thalassemia major in offspring. This is one of the factors playing a major role in the propagation of beta thalassemia gene in Pakistani population, and become a serious hindrance for the thalassemia prevention program in Pakistan.

Effects of Astragalus polysaccharide on the erythroid lineage and microarray analysis in K562 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus polysaccharide (APS), obtained from Astragalus membranaceus, displays a range of activities in many systems, including the promotion of immune responses, anti-inflammation, and the protection of vessels. It possesses potent pharmacological activity on differentiation to the erythroid lineage.

AIM OF THE STUDY

To investigate the effects of APS on the erythroid differentiation and the mechanism of action by microarray analysis in K562 cells.

MATERIALS AND METHODS

Benzidine staining, semi-quantitative RT-PCR, Western blot and microarray methods were used to survey the effects of APS on inducing erythroid differentiation and the changes of gene expression profile in K562 cells.

RESULTS

Of the 13.2% positive cells detected by benzidine staining, the induction was the highest with 200 microg/ml APS on 72h. Ggamma-mRNA expression and fetal hemoglobin synthesis were significantly up-regulated. Microarray analysis showed that 31 genes were up-regulated and 108 genes were down-regulated. These differential expression genes generally regulate protein binding, cellular metabolic process, the cell proliferation, and transcriptional activator activity. The gamma-globin gene was up-regulated, the genes related with erythroid differentiation such as LMO2, Runx1 and GTF2I were up-regulated, while Bklf, Eklf, EPHB4 and Sp1 were down-regulated.

CONCLUSIONS

Our studies indicate that APS indicate potent activities on the erythroid differentiation by modulating genes of LMO2, Klf1, Klf3, Runx1, EphB4 and Sp1, increasing gamma-globin mRNA expression and fetal hemoglobin synthesis in K562 cells.

Induction of endogenous gamma-globin gene expression with decoy oligonucleotide targeting Oct-1 transcription factor consensus sequence

Human β-globin disorders are relatively common genetic diseases cause by mutations in the β-globin gene. Increasing the expression of the γ-globin gene has great benefits in reducing complications associated with these diseases. The Oct-1 transcription factor is involved in the transcriptional regulation of the γ-globin gene. The human γ-globin genes (both Aγ and Gγ-globin genes) carry three Oct-1 transcription factor consensus sequences within their promoter regions. We have studied the possibility of inducing γ-globin gene expression using decoy oligonucleotides that target the Oct-1 transcription factor consensus sequence. A double-stranded 22 bp decoy oligonucleotide containing the Oct-1 consensus sequence was synthesized. The results obtained from our in vitro binding assay revealed a strong competitive binding of the decoy oligonucleotide for the Oct-1 transcription factor. When K562 human erythroleukemia cells were treated with the Oct-1 decoy oligonucleotide, significant increases in the level of the γ-globin mRNA were observed. The results of our western blots further demonstrated significant increases of the fetal hemoglobin (HbF, α2γ2) in the Oct-1 decoy oligonucleotide-treated K562 cells. The results of our immunoprecipitation (IP) studies revealed that the treatment of K562 cells with the Oct-1 decoy oligonucleotide significantly reduced the level of the endogenous γ-globin gene promoter region DNA co-precipitated with the Oct-1 transcription factor. These results suggest that the decoy oligonucleotide designed for the Oct-1 transcription factor consensus sequence could induce expression of the endogenous γ-globin gene through competitive binding of the Oct-1 transcription factor, resulting in activation of the γ-globin genes. Therefore, disrupting the bindings of the Oct-1 transcriptional factors with the decoy oligonucleotide provides a novel approach for inducing expression of the γ-globin genes. It also provides an innovative strategy for the treatment of many disease conditions, including sickle cell anemia and β-thalassemia.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Human Fetal Hemoglobin Expression Is Regulated by the Developmental Stage-Specific Repressor BCL11A

Differences in the amount of fetal hemoglobin (HbF) that persists into adulthood affect the severity of sickle cell disease and the β-thalassemia syndromes. Genetic association studies have identified sequence variants in the gene BCL11A that influence HbF levels. Here, we examine BCL11A as a potential regulator of HbF expression. The high-HbF BCL11A genotype is associated with reduced BCL11A expression. Moreover, abundant expression of full-length forms of BCL11A is developmentally restricted to adult erythroid cells. Down-regulation of BCL11A expression in primary adult erythroid cells leads to robust HbF expression. Consistent with a direct role of BCL11A in globin gene regulation, we find that BCL11A occupies several discrete sites in the β-globin gene cluster. BCL11A emerges as a therapeutic target for reactivation of HbF in β-hemoglobin disorders.