bims-conane 2025-09-21 papers

Med. 2025 Sep 12. pii: S2666-6340(25)00271-5. [Epub ahead of print]6(9): 100844

The ENERGIZE trial: Is mitapivat ready to take center stage in NTDT management?

The ENERGIZE trial1 represents a step forward in managing non-transfusion-dependent thalassemia, demonstrating that mitapivat, a novel pyruvate kinase activator, may rapidly increase hemoglobin levels and reduce patient-reported fatigue. Efficacy was shown in both α- and β-thalassemia subtypes. Longer follow-up is required to document mitapivat-sustained effects and impact on disease-related complications.

DOI: https://doi.org/10.1016/j.medj.2025.100844

Biochim Biophys Acta Gene Regul Mech. 2025 Sep 16. pii: S1874-9399(25)00041-0. [Epub ahead of print]1868(4): 195116

Transcriptional activation of the PKLR gene by novel erythroid-specific regulatory elements.

Yea Woon Kim, Jin Kang, AeRi Kim.

The pyruvate kinase L/R (PKLR) gene encodes the L- and R-type isoforms of pyruvate kinase, which catalyze the final step of glycolysis in mammals. The L-type isozyme is mainly found in liver cells, whereas the R-type isozyme is produced specifically in erythroid cells. To investigate the transcriptional activation of the PKLR gene for the R-type isozyme, we analyzed chromatin features-including DNase I sensitivity, histone modifications, and enhancer-promoter interactions-in erythroid K562 and non-erythroid HUVEC cells. Putative regulatory elements, including a promoter and two enhancers, were identified near the PKLR locus in K562 cells. Depletion of H3K4me1 and H3K27ac, histone marks associated with active enhancers, through mutation of histone methyltransferases led to a marked reduction in PKLR transcription, while transcription of a nearby gene remained stable. These regulatory elements were highly occupied by the erythroid-specific transcription factors GATA1 and TAL1. Loss of either factors disrupted local H3K27ac and reduced the recruitment of chromatin-looping factors, resulting in decreased PKLR transcription. Furthermore, CRISPR/Cas9-mediated deletion of the putative regulatory elements significantly diminished PKLR transcription, demonstrating their functional importance. Collectively, these findings highlight the essential role of these regulatory elements in activating PKLR transcription in erythroid cells and emphasize the requirement of erythroid-specific factors for their function.

Keywords: Erythroid-specific regulatory elements; GATA1; PKLR; TAL1; Transcription

DOI: https://doi.org/10.1016/j.bbagrm.2025.195116

Ann Hematol. 2025 Sep 16.

Genetic biomarkers and crucial cell subsets of iron metabolism in Beta-Thalassemia: insights from bioinformatics and experimental validation.

Renrong Wei, Dan Qiu, Xiangxing Zeng.

Approximately 1.5% of individuals with hemoglobin disorders carry the β-thalassemia gene variant, impacting around 40,000 newborns annually. Given the incomplete understanding of β-thalassemia pathogenesis, there is an urgent need to identify effective biomarkers to advance research, diagnosis, and treatment. This study aims to identify potential biomarkers for two key purposes: (1) diagnosing transfusion-dependent β-thalassemia (TDT) and (2) detecting iron overload complications, with a focus on functional markers that reflect iron metabolism dysregulation in TDT. This study integrates transcriptomic data from the Genome Sequence Archive dataset (CRA003639) with bioinformatics analysis to identify potential biomarkers associated with β-thalassemia. Subsequently, Hbb-bs and Hbb-bt double knockout mice were used to establish a β-thalassemia model, while C57BL/6JCya mice served as the control group, to validate the identified biomarkers through animal experiments. Seventeen reliable cell subsets were identified through rigorous annotation and screening. Quantitative analysis revealed a decreased proportion of immune cells (natural killer [NK] cells, T cells, macrophages, neutrophils, and monocytes) and an increased proportion of erythroid cells in the β-thalassemia group. Cell subset analysis focused on subsets that closely communicated with erythroid cells. Enrichment analysis of driver genes in these subsets revealed iron metabolism-related pathways in Erythroid_02 and Erythroid_03, and a ferroptosis-related pathway in Erythroid_05. Thalassemia model mice exhibited stronger iron ion fluorescence signals in primary hepatocytes, increased levels of total iron, Fe2+, and Fe3+ in liver tissue, and decreased serum iron (SI) levels, indicating iron metabolism disorders. Reverse transcription polymerase chain reaction (RT-PCR) results showed differential gene expression, with BCL2L1, Hepb1, and Prdx6 downregulated and Spta1 and Snca upregulated in the TDT model group. This study comprehensively characterizes TDT at the cellular and molecular levels, offering insights into its pathogenesis and identifying potential therapeutic targets.

Keywords: Animal models; Biomarkers, genetic; Erythrocytes; Gene expression profiling; Iron metabolism; Thalassemia, beta

DOI: https://doi.org/10.1007/s00277-025-06605-6

PLoS One. 2025 ;20(9): e0332039

Spectrum of glucose-6-phosphate dehydrogenase (G6PD) mutations and trends in hemoglobin levels among adult dengue patients in Thailand.

Supat Chamnanchanunt, Beatriz Aira C Jacob, Vipa Thanachartwet, Varunee Desakorn, Natsamon Singha-Art, Duangjai Sahassananda, Kamonwan Chamchoy, Naveen Eugene Louis, Muawiaa Ahmed Hamza, Nurriza Ab Latif, Syazwani Itri Amran, Henry A F Stephens, Wang Nguitragool, Usa Boonyuen.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in humans that may exacerbate clinical outcomes during viral infections such as dengue, particularly in regions where both conditions are endemic. This study aimed to characterize the spectrum of G6PD mutations and explore trends in hemoglobin levels among adult dengue patients in Thailand. Samples from 231 adult patients diagnosed with dengue were analyzed. G6PD deficiency was identified in 24 individuals (10.4%), while G6PD mutations were detected in 111 patients (48.1%). The most frequently observed mutations include a combination of synonymous and intronic mutations (c.1311C > T and c.1365-13T > C), compound mutation of G6PD Viangchan (c. 871G > A, c.1311C > T and c.1365-13T > C), and a deletion variant (c.486-34delT). Additionally, a novel variant, c.1439T > C, was identified and named "G6PD Phaya Thai". Patients carrying G6PD mutations exhibited different hemoglobin level trends compared to those without mutations. Specifically, while hemoglobin levels increased from the febrile to critical phase in patients without mutations, a significant decline was observed in mutation carriers. Median hemoglobin levels differed significantly between the two groups during both the febrile and critical phases (p = 0.02 and p < 0.001, respectively). Biochemical and structural analyses of uncharacterized variants, G6PD Phaya Thai and G6PD Viangchan+Chinese-5, suggested structural instability as a possible mechanism for the observed deficiency. These findings highlight the need for further investigation into the potential role of G6PD variants in dengue-related anemia. Routine G6PD screening and continuous hemoglobin monitoring may help identify individuals at risk of hemoglobin decline and guide supportive care strategies in dengue-endemic regions.

DOI: https://doi.org/10.1371/journal.pone.0332039

Cell Rep Med. 2025 Sep 17. pii: S2666-3791(25)00435-5. [Epub ahead of print] 102362

Lentiviral vectors for hematopoietic stem cell gene therapy restore α-globin expression in α-thalassemia red blood cells.

Eva E R Segura, Kevyn Hart, Beatriz Campo Fernandez, Devin Brown, Kevin Tam, Andrea Gutierrez Garcia, Eva Seigneurbieux, Karen Li, Carol Mulumba, Emma Blakely, Katelyn Masiuk, Roshani Sinha, Devesh Sharma, John Everett, Matthew Hogenauer, M Kyle Cromer, Frederic Bushman, Tippi C MacKenzie, Donald B Kohn.

Alpha thalassemia major (ATM) is an inherited blood disorder caused by the absence of all four α-globin genes (HBA2/1), resulting in severe anemia and lifelong transfusion dependence. While allogeneic hematopoietic stem cell transplantation (HSCT) offers a potential cure, donor availability remains limited. We present a gene therapy approach for autologous HSCT using lentiviral vectors (LVs) to deliver HBA2 under the regulation of optimized β-globin locus control region (LCR) enhancers, restoring α-globin expression in red blood cells. The best-performing LVs, erythroid vector-alpha (EV-α) and EV-α-UV, achieved up to 100% transduction efficiency in human hematopoietic stem and progenitor cells (HSPCs), optimal vector copy numbers, and safe integration profiles. ATM-derived HSPCs from three donors treated with these LVs yielded α/β-globin mRNA and chain ratios within the therapeutic range (∼0.5+), and restored hemoglobin levels by 50%-100%. These findings establish the safety and clinical potential of EV-α and EV-α-UV as a promising autologous stem cell gene therapy for ATM.

Keywords: alpha globin; alpha thalassemia major; anemia; autologous; beta-globin LCR; gene therapy; hematopoietic stem cell; hemoglobin level; lentiviral vectors; red blood cells

DOI: https://doi.org/10.1016/j.xcrm.2025.102362