Search Results (46)

Testicular orphan receptors TR2 and TR4 serve as central regulators of erythropoiesis, orchestrating the entire continuum of erythroid progenitor cell proliferation, differentiation, and maturation. As core components of the direct repeat erythroid determinant (DRED) complex, they activate erythroid-specific transcriptional programs to dynamically control the spatiotemporal expression of globin genes. These nuclear receptors not only engage in functional interactions with key erythroid transcription factors GATA1 and KLF1 to coregulate erythroid differentiation and maturation but also recruit epigenetic modifier complexes such as DNMT1 and LSD1 to modulate chromatin states dynamically. Research has established that dysfunctions in TR2/TR4 are implicated in β-thalassemia and sickle cell disease (SCD): β-thalassemia is associated with the defective silencing of γ-globin genes, while in SCD, TR2/TR4 antagonizes BCL11A to reactivate fetal hemoglobin (HbF) expression. This review systematically dissects the molecular regulatory networks of TR2/TR4 in erythroid cells, interprets their dual regulatory properties across different stages of erythroid differentiation, and explores the therapeutic potential of targeting TR2/TR4 for treating erythroid-related disorders such as β-thalassemia and SCD, thereby providing novel directions for hematological disorder therapy. Full article

Sickle cell disease (SCD) is a group of recessive diseases caused by the β^S sickling mutation of HBB in homozygosity or in compound heterozygosity with other pathogenic HBB mutations. Patients with severe SCD typically experience painful vaso-occlusive crises and other pain-related phenomena, including acute chest syndrome, priapism, dactylitis, avascular necrosis, and splenic sequestration and infarction. High variability of pain-related phenomena per SCD genotype indicates genetic disease modifiers (GDMs) as pathology determinants and, thus, as critical to prognosis, treatment choice, and therapy development. Articles likely holding genetic information for SCD pain phenomena were identified in PubMed and SCOPUS for article quality assessment and extraction of corresponding GDMs and observations indicative of development areas in our understanding of SCD GDMs. This process led to the initial selection of 183 articles matching the search terms, which, after two-step selection, resulted in the inclusion of 100 articles for content analysis and of significant findings for GDMs from 37 articles. Published data point to gender effects and to 51 GDM SNVs, deletions, and regions, including globin genes and significant overrepresentation of gene ontology pathways related, e.g., to oxidative stress, hypoxia, and regulation of blood pressure. Analyzed articles further pointed to additional candidate GDMs affecting SCD VOC and pain phenomena and to potential confounding factors for GWAS analyses. We found that despite the critical importance of VOC and pain phenomena for SCD pathology, corresponding clinically relevant genetic insights are held back by a shortage of large-scale, systematic multi-ethnic efforts, as undertaken by the INHERENT Network. Full article

Thalassemia is an autosomal recessive hereditary chronic hemolytic anemia characterized by a partial or complete deficiency in the synthesis of alpha- or beta-globin chains, which are essential components of adult hemoglobin. Mutations in the globin genes lead to the production of unstable globin chains that precipitate within cells, causing hemolysis. This shortens the lifespan of mature red blood cells (RBCs) and results in the premature destruction of RBC precursors in the bone marrow. Regular red blood cell transfusions are the standard treatment for thalassemia. However, these transfusions can lead to increased iron overload, which can impair vital systems such as the liver, heart, ovaries, and endocrine system. Focusing on female reproductive endocrinology, recurrent blood transfusions can cause iron accumulation in the pituitary and hypothalamus, leading to hypogonadotropic hypogonadism (HH), the most common endocrinopathy in these patients, affecting 40–91% of women. Recurrent transfusions and the resulting iron overload can also lead to oxidative stress and ovarian damage in patients with beta-thalassemia major (BTM). Despite advancements in iron chelation therapy, hypothalamic–pituitary damage associated with HH contributes to subfertility and sexual dysfunction, often with little to no recovery. In women exposed to gonadotoxic drugs, particularly those with BTM, anti-Mullerian hormone (AMH)—a marker of ovarian reserve—is frequently used to assess ovarian damage. This review aims to explore the pathophysiology of β-thalassemia and its major clinical manifestations, with a focus on endocrine complications and their impact on ovarian reserve. It also investigates how metabolomics can provide insights into the disease’s metabolic alterations and inform current and emerging therapeutic strategies to mitigate complications and optimize patient outcomes, potentially leading to more effective and personalized treatments. Full article

Background/Objectives: Beta-thalassemia (BTH), a genetic disorder resulting from beta-globin gene mutations, affects over 1.5 million people globally. The disorder’s multifactorial impact on male fertility, particularly through oxidative stress (OS), warrants focused study. This review examines the mechanisms of OS in TM, its implications for male infertility, and the potential of antioxidant therapies to mitigate fertility challenges. Methods: A non-systematic review was conducted using the PubMed, Cochrane, and Medscape databases, focusing on studies on beta-thalassemia (BTH), erectile dysfunction (ED), hormonal alterations, and OS. Studies were screened based on relevance, language, and topic, with 71 articles meeting the inclusion criteria after removing duplicates. Results: The findings reveal that OS, exacerbated by iron overload from regular blood transfusions, is significantly associated with impaired sperm quality and fertility in patients with TM. Iron toxicity affects gonadotropin levels, reduces sperm quality, and contributes to hypogonadism. Additionally, antioxidant therapies show promise in reducing OS-induced sperm damage, though efficacy is limited by a lack of robust clinical trials. Conclusions: OS plays a considerable role in male infertility among patients with TM, primarily through iron-induced sperm damage and hormonal disruptions. While antioxidant therapies may offer a partial remedy, further research is necessary to understand OS’s mechanisms in TM and develop effective fertility treatments. This review highlights the need for personalized antioxidant approaches to improve reproductive outcomes in this population. Full article

Introduction: Generally, microcytic anaemia is caused by sideropenia or a genetic gap. The suspicion that microcytic anaemia is caused by a genetic gap must always be considered in the face of an inadequate response to martial therapy. The aim of this paper is to highlight how biochemical diagnosis alone is sometimes not sufficient to understand the cause of microcytic anaemia. For this reason, for a correct genotype–phenotype correlation, it is essential to identify the defective gene underlying the microcytic anaemia. Detailed Case Description: This case concerns a married couple who both have microcytic anaemia. They came to our attention because the lady, pregnant at 12 weeks, underwent screening for chromosomal abnormalities using combined tests in the first trimester of pregnancy. A biochemical screening performed ten years earlier showed that both spouses were healthy carriers of the beta-thalassemia trait. A careful analysis of the biochemical data and an in-depth molecular diagnosis of the alpha and beta globin genes showed that the woman was a healthy carrier of the beta-thalassemia trait while the husband was a healthy carrier of a mutation in the ALAS2 gene. Analysis of the biochemical data of her husband and family members revealed that she had X-linked microcytic sideroblastic anaemia caused by an alteration in the function of the ALAS2 (5′-Aminolevulinate Synthase 2) gene located on the short arm of the X chromosome (Xp11.21). Discussion and Conclusions: This result is very relevant as, during genetic counselling, we explained to the couple that invasive prenatal diagnosis was not necessary as there is no risk of procreating a transfusion-dependent individual. Full article

Hemoglobinopathies, namely β-thalassemia and sickle cell disease (SCD), are hereditary diseases, characterized by molecular genetic aberrations in the beta chains of hemoglobin. These defects affect the normal production of hemoglobin with severe anemia due to less or no amount of beta globins in patients with β-thalassemia (quantitative disorder), while SCD is a serious disease in which a mutated form of hemoglobin distorts the red blood cells into a crescent shape at low oxygen levels (qualitative disorder). Despite the revolutionary progress in recent years with the approval of gene therapy and gene editing for specific patients, there is an unmet need for highlighting the mechanisms influencing hemoglobin production and for the development of novel drugs and targeted therapies. The identification of the transcription factors and other genetic modifiers of hemoglobin expression is of utmost importance for discovering novel therapeutic approaches for patients with hemoglobinopathies. The aim of this review is to describe these complex molecular mechanisms and pathways affecting hemoglobin expression and to highlight the relevant investigational approaches or pharmaceutical interventions focusing on restoring the hemoglobin normal function by linking the molecular background of the disease with the clinical perspective. All the associated drugs increasing the hemoglobin expression in patients with hemoglobinopathies, along with gene therapy and gene editing, are also discussed. Full article

Elevated fetal hemoglobin (HbF), which is partly controlled by genetic modifiers, ameliorates disease severity in β hemoglobinopathies. Understanding the genetic basis of this trait holds great promise for personalized therapeutic approaches. PubMed, MedRxiv, and the GWAS Catalog were searched up to May 2024 to identify eligible GWAS studies following PRISMA guidelines. Four independent reviewers screened, extracted, and synthesized data using narrative and descriptive methods. Study quality was assessed using a modified version of the Q-Genie tool. Pathway enrichment analysis was conducted on gene lists derived from the selected GWAS studies. Out of 113 initially screened studies, 62 underwent full-text review, and 16 met the inclusion criteria for quality assessment and data synthesis. A total of 939 significant SNP-trait associations (p-value < 1 × 10⁻⁵) were identified, mapping to 133 genes (23 with overlapping variant positions) and 103 intergenic sequences. Most SNP-trait associations converged around BCL11A (chr.2), HBS1L-MYB, (chr.6), olfactory receptor and beta globin (HBB) gene clusters (chr.11), with less frequent loci including FHIT (chr.3), ALDH8A1, BACH2, RPS6KA2, SGK1 (chr.6), JAZF1 (chr.7), MMP26 (chr.11), COCH (chr.14), ABCC1 (chr.16), CTC1, PFAS (chr.17), GCDH, KLF1, NFIX, and ZBTB7A (chr.19). Pathway analysis highlighted Gene Ontology (GO) terms and pathways related to olfaction, hemoglobin and haptoglobin binding, and oxygen carrier activity. This systematic review confirms established genetic modifiers of HbF level, while highlighting less frequently associated loci as promising areas for further research. Expanding research across ethnic populations is essential for advancing personalized therapies and enhancing outcomes for individuals with sickle cell disease or β-thalassemia. Full article

Thalassemia represents a diverse group of inherited hematological disorders characterized by defective globin chain synthesis, leading to chronic anemia and associated complications. The complicated pathophysiology of beta-thalassemia involves genetic mutations or rarely deletions of the beta-globin gene on chromosome 11 whereas alpha-thalassemia involves deletions in the HBA1 and HBA2 genes or occasionally alterations to the DNA sequence in or around these genes. These mutation and deletion effects disrupt the balance of α/β-globin chain production, resulting in ineffective erythropoiesis, hemolysis, and a cascade of clinical manifestations including anemia, bone deformities, and iron overload. Advances in diagnostic techniques have enhanced our ability to detect and characterize these mutations, facilitating early and accurate diagnoses. Current management strategies encompass regular blood transfusions, the use of hydroxyurea to improve hemoglobin levels, and iron chelation therapy to prevent iron-related organ damage. Moreover, other therapeutics such as thalidomide for those not responding to hydroxyurea, Sirolimus for patients with immunodeficiencies, and use of vitamin E as an antioxidant have proven to be effective. Innovative therapies such as gene therapy and bone marrow transplantation offer promising curative potential, opening a new era in the treatment of thalassemia. This review focuses on pathophysiological mechanisms underlying thalassemia, explores the diagnostic methodologies, and highlights recent advancements in therapeutic approaches. Full article

Synthetic mRNA produced by in vitro transcription (ivt mRNA) is the active pharmaceutical ingredient of approved anti-COVID-19 vaccines and of many drugs under development. Such synthetic mRNA typically contains several hundred bases of non-coding “untranslated” regions (UTRs) that are involved in the stabilization and translation of the mRNA. However, UTRs are often complex structures, which may complicate the entire production process. To eliminate this obstacle, we managed to reduce the total amount of nucleotides in the UTRs to only four bases. In this way, we generate minimal ivt mRNA (“minRNA”), which is less complex than the usual optimized ivt mRNAs that are contained, for example, in approved vaccines. We have compared the efficacy of minRNA to common augmented mRNAs (with UTRs of globin genes or those included in licensed vaccines) in vivo and in vitro and could demonstrate equivalent functionalities. Our minimal mRNA design will facilitate the further development and implementation of ivt mRNA-based vaccines and therapies. Full article

Genome-Wide Association Studies (GWASs) have identified a huge number of variants associated with different traits. However, their validation through in vitro and in vivo studies often lags well behind their identification. For variants associated with traits or diseases of biomedical interest, this gap delays the development of possible therapies. This issue also impacts beta-hemoglobinopathies, such as beta-thalassemia and sickle cell disease (SCD). The definitive cures for these diseases are currently bone marrow transplantation and gene therapy. However, limitations regarding their effective use restrict their worldwide application. Great efforts have been made to identify whether modulators of fetal hemoglobin (HbF) and, to a lesser extent, hemoglobin A2 (HbA₂) are possible therapeutic targets. Herein, we performed the post-GWAS in vivo validation of two genes, cyclin D3 (CCND3) and nuclear factor I X (NFIX), previously associated with HbF and HbA₂ levels. The absence of Ccnd3 expression in vivo significantly increased g (HbF) and d (HbA₂) globin gene expression. Our data suggest that CCND3 is a possible therapeutic target in sickle cell disease. We also confirmed the association of Nfix with γ-globin gene expression and present data suggesting a possible role for Nfix in regulating Kruppel-like transcription factor 1 (Klf1), a master regulator of hemoglobin switching. This study contributes to filling the gap between GWAS variant identification and target validation for beta-hemoglobinopathies. Full article

Therapy via the gene addition of the anti-sickling β^AS3-globin transgene is potentially curative for all β-hemoglobinopathies and therefore of particular clinical and commercial interest. This study investigates GLOBE-based lentiviral vectors (LVs) for β^AS3-globin addition and evaluates strategies for an increased β-like globin expression without vector dose escalation. First, we report the development of a GLOBE-derived LV, GLV2-βAS3, which, compared to its parental vector, adds anti-sickling action and a transcription-enhancing 848-bp transcription terminator element, retains high vector titers and allows for superior β-like globin expression in primary patient-derived hematopoietic stem and progenitor cells (HSPCs). Second, prompted by our previous correction of HBB^{IVSI−110(G>A)} thalassemia based on RNApol(III)-driven shRNAs in mono- and combination therapy, we analyzed a series of novel LVs for the RNApol(II)-driven constitutive or late-erythroid expression of HBB^{IVSI−110(G>A)}-specific miRNA30-embedded shRNAs (shRNAmiR). This included bifunctional LVs, allowing for concurrent β^AS3-globin expression. LVs were initially compared for their ability to achieve high β-like globin expression in HBB^{IVSI−110(G>A)}-transgenic cells, before the evaluation of shortlisted candidate LVs in HBB^{IVSI−110(G>A)}-homozygous HSPCs. The latter revealed that β-globin promoter-driven designs for monotherapy with HBB^{IVSI−110(G>A)}-specific shRNAmiRs only marginally increased β-globin levels compared to untransduced cells, whereas bifunctional LVs combining miR30-shRNA with β^AS3-globin expression showed disease correction similar to that achieved by the parental GLV2-βAS3 vector. Our results establish the feasibility of high titers for LVs containing the full HBB transcription terminator, emphasize the importance of the HBB terminator for the high-level expression of HBB-like transgenes, qualify the therapeutic utility of late-erythroid HBB^{IVSI−110(G>A)}-specific miR30-shRNA expression and highlight the exceptional potential of GLV2-βAS3 for the treatment of severe β-hemoglobinopathies. Full article

mRNA-based therapeutics have been found to be a promising treatment strategy in immunotherapy, gene therapy, and cancer treatments. Effectiveness of mRNA therapeutics depends on the level and duration of a desired protein’s expression, which is determined by various cis- and trans-regulatory elements of the mRNA. Sequences of 5′ and 3′ untranslated regions (UTRs) are responsible for translational efficiency and stability of mRNA. An optimal combination of the regulatory sequences allows researchers to significantly increase the target protein’s expression. Using both literature data and previously obtained experimental data, we chose six sequences of 5′UTRs (adenoviral tripartite leader [TPL], HBB, rabbit β-globin [Rabb], H4C2, Moderna, and Neo2) and five sequences of 3′UTRs (mtRNR-EMCV, mtRNR-AES, mtRNR-mtRNR, BioNTech, and Moderna). By combining them, we constructed 30 in vitro transcribed RNAs encoding firefly luciferase with various combinations of 5′- and 3′UTRs, and the resultant bioluminescence was assessed in the DC2.4 cell line at 4, 8, 24, and 72 h after transfection. The cellular data enabled us to identify the best seven combinations of 5′- and 3′UTRs, whose translational efficiency was then assessed in BALB/c mice. Two combinations of 5′- and 3′UTRs (5′Rabb-3′mtRNR-EMCV and 5′TPL-3′Biontech) led to the most pronounced increase in the luciferase amount in the in vivo experiment in mice. Subsequent analysis of the stability of the mRNA indicated that the increase in luciferase expression is explained primarily by the efficiency of translation, not by the number of RNA molecules. Altogether, these findings suggest that 5′UTR-and-3′UTR combinations 5′Rabb-3′mtRNR- EMCV and 5′TPL-3′Biontech lead to high expression of target proteins and may be considered for use in preventive and therapeutic modalities based on mRNA. Full article

Thalassemia represents one of the most common genetic disorders worldwide, characterized by defects in hemoglobin synthesis. The affected individuals suffer from malfunctioning of one or more of the four globin genes, leading to chronic hemolytic anemia, an imbalance in the hemoglobin chain ratio, iron overload, and ineffective erythropoiesis. Despite the challenges posed by this condition, recent years have witnessed significant advancements in diagnosis, therapy, and transfusion support, significantly improving the prognosis for thalassemia patients. This research empirically evaluates the efficacy of models constructed using classification methods and explores the effectiveness of relevant features that are derived using various machine-learning techniques. Five feature selection approaches, namely Chi-Square (χ2), Exploratory Factor Score (EFS), tree-based Recursive Feature Elimination (RFE), gradient-based RFE, and Linear Regression Coefficient, were employed to determine the optimal feature set. Nine classifiers, namely K-Nearest Neighbors (KNN), Decision Trees (DT), Gradient Boosting Classifier (GBC), Linear Regression (LR), AdaBoost, Extreme Gradient Boosting (XGB), Random Forest (RF), Light Gradient Boosting Machine (LGBM), and Support Vector Machine (SVM), were utilized to evaluate the performance. The χ2 method achieved accuracy, registering 91.56% precision, 91.04% recall, and 92.65% f-score when aligned with the LR classifier. Moreover, the results underscore that amalgamating over-sampling with Synthetic Minority Over-sampling Technique (SMOTE), RFE, and 10-fold cross-validation markedly elevates the detection accuracy for αT patients. Notably, the Gradient Boosting Classifier (GBC) achieves 93.46% accuracy, 93.89% recall, and 92.72% F1 score. Full article

The anticancer drug mithramycin (MTH), has been proposed for drug repurposing after the finding that it is a potent inducer of fetal hemoglobin (HbF) production in erythroid precursor cells (ErPCs) from β-thalassemia patients. In this respect, previously published studies indicate that MTH is very active in inducing increased expression of γ-globin genes in erythroid cells. This is clinically relevant, as it is firmly established that HbF induction is a valuable approach for the therapy of β-thalassemia and for ameliorating the clinical parameters of sickle-cell disease (SCD). Therefore, the identification of MTH biochemical/molecular targets is of great interest. This study is inspired by recent robust evidence indicating that the expression of γ-globin genes is controlled in adult erythroid cells by different transcriptional repressors, including Oct4, MYB, BCL11A, Sp1, KLF3 and others. Among these, BCL11A is very important. In the present paper we report evidence indicating that alterations of BCL11A gene expression and biological functions occur during MTH-mediated erythroid differentiation. Our study demonstrates that one of the mechanisms of action of MTH is a down-regulation of the transcription of the BCL11A gene, while a second mechanism of action is the inhibition of the molecular interactions between the BCL11A complex and specific sequences of the γ-globin gene promoter. Full article

β-Thalassemia is a subgroup of inherited blood disorders associated with mild to severe anemia with few and limited conventional therapy options. Lately, lentiviral vector-based gene therapy has been successfully applied for disease treatment. However, the current development of non-viral episomal vectors (EV), non-integrating and non-coding for viral proteins, may be helpful in generating valid alternatives to viral vectors. We constructed a non-viral, episomal vector pEPβ-globin for the physiological β-globin gene based on two human chromosomal elements: the scaffold or matrix attachment region (S/MAR), allowing for long nuclear retention and non-integration and the β-globin replication initiation region (IR), allowing for enhancement of replication and establishment. After nucleofections into K562 cells with a transfection efficiency of 24.62 ± 7.7%, the vector induces stable transfection and is detected in long-term cultures as a non-integrating, circular episome expressing the β-globin gene efficiently. Transfections into CD34+ cells demonstrate an average efficiency of 15.57 ± 11.64%. In the colony-forming cell assay, fluorescent colonies are 92.21%, which is comparable to those transfected with vector pEP-IR at 92.68%. Additionally, fluorescent colonies produce β-globin mRNA at a physiologically 3-fold higher level than the corresponding non-transfected cells. Vector pEPβ-globin provides the basis for the development of therapeutic EV for gene therapy of β-thalassemias. Full article