hemoglobin switching

The switch from fetal (HBG) to adult (HBB) -globin gene transcription in erythroid cells serves as a paradigm for a complex, clinically relevant developmental gene regulatory program. We previously identified HIC2 as a regulator of the switch by inhibiting the transcription of BCL11A, a key repressor of HBG production. HIC2 is highly expressed in fetal cells but the mechanism of its regulation is unclear. Here we report that HIC2 developmental expression is controlled by miRNAs, as loss of global miRNA biogenesis through DICER1 depletion leads to upregulation of HIC2 and HBG mRNA...

Fetal-to-adult hemoglobin switching is controlled by programmed silencing of γ-globin while the re-activation of fetal hemoglobin (HbF) is an effective strategy for ameliorating the clinical severity of β-thalassemia and sickle cell disease. The identification of enhancer RNAs (eRNAs) related to the fetal (α2γ2) to adult hemoglobin (α2β2) switching remains incomplete. In this study, the transcriptomes of GYPA+ cells from six β-thalassemia patients with extreme HbF levels were sequenced to identify differences in patterns of noncoding RNA expression...

Aim: Many Muslims with Type II diabetes (T2DM) fast during Ramadan, which can put them at increased risk of hypoglycemia. This sub-analysis of the global DIA-RAMADAN study assessed the effectiveness and safety of gliclazide modified release (MR) 60 mg in the Bangladeshi cohort. Materials & methods: DIA-RAMADAN was an international, prospective, observational study conducted in adult T2DM patients intending to fast and receiving gliclazide MR 60 mg once daily for ≥90 days before Ramadan...

The transcription factor BCL11A is a critical regulator of the switch from fetal hemoglobin (HbF: α 2 γ 2 ) to adult hemoglobin (HbA: α 2 β 2 ) during development. BCL11A binds at a cognate recognition site (TGACCA) in the γ-globin gene promoter and represses its expression. DNA-binding is mediated by a triple zinc finger domain, designated ZnF456. Here, we report comprehensive investigation of ZnF456, leveraging X-ray crystallography and NMR to determine the structures in both the presence and absence of DNA...

Candida albicans is a major human pathogenic fungus that is distinguished by its capability to switch from a yeast to a hyphal morphology under different conditions. Here, we analyze the cellular effects of high concentrations of the iron chelator bathophenanthroline disulfonate (BPS). BPS inhibits cellular growth by withholding iron, but when iron chelation is overcome by the addition of hemoglobin as an iron source, the cells resume growth as hyphae. The BPS hyphal induction pathway was characterized by identifying the hyphal-specific transcription factors that it requires and by a forward genetic screen for mutants that fail to form hyphae in BPS using a transposon library generated in a haploid strain...

AIMS: To describe the clinical characteristics and medication purchases of insulin-treated adults in Finland at index (January 1, 2012 or first insulin purchase) and December 31, 2019. Additionally, to describe basal insulin (BI) treatment patterns and associated changes in hemoglobin A1c (HbA1c) values. MATERIALS AND METHODS: In this descriptive study using nationwide registries, we included adults with at least two reimbursed insulin purchases within 12 months of the first purchase between January 1, 2012 and December 31, 2019...

The formation of new red blood cells (erythropoiesis) has served as a paradigm for understanding cellular differentiation and developmental control of gene expression. The metabolic regulation of this complex, coordinated process remains poorly understood. Each step of erythropoiesis, including lineage specification of hematopoietic stem cells, proliferation, differentiation, and terminal maturation into highly specialized oxygen-carrying cells, has unique metabolic requirements. Developing erythrocytes in mammals are also characterized by unique metabolic events such as loss of mitochondria with switch to glycolysis, ejection of nucleus and organelles, high level heme and hemoglobin synthesis, and antioxidant requirement to protect hemoglobin molecules...

The mechanism that drives the switch from fetal to adult hemoglobin (Hb) provides a therapeutic target for β-thalassemia. We have previously identified that hypermethylation of transcription factor ERF promoter reactivated γ-globin expression. To uncover the mechanism underlying the hypermethylation of ERF promoter, we performed RNA sequencing in β0 /β0 -thalassemia patients and identified an upregulated long noncoding RNA (RP11-196G18.23) associated with HbF production. RP11-196G18...

Sickle cell disease (SCD) affects millions worldwide, yet there are few therapeutic options. To develop effective treatments, preclinical models that recapitulate human physiology and SCD pathophysiology are needed. SCD arises from a single Glu-to-Val substitution at position 6 in the β subunit of hemoglobin (Hb), promoting Hb polymerization and subsequent disease. Sheep share important physiological and developmental characteristics with humans, including the same developmental pattern of fetal to adult Hb switching...

Insulin edema is a poorly understood complication of insulin therapy. It has been reported in patients with both type 1 and 2 diabetes mellitus and typically occurs in patients with newly diagnosed or poorly controlled diabetes mellitus either after initiation or intensification of insulin therapy. A 20-year-old man presented with anorexia, polydipsia, and weight loss. Serum glucose on admission was 824 mg/dL (45.8 mmol/L) and hemoglobin A1c was >14.0. Additional workup was notable for positive anti-IA2 antibodies and low C-peptide of 0...

PURPOSE: Fetal hemoglobin (HbF) upregulation is a mitigating factor in β-hemoglobinopathies therapy like β-thalassemia and sickle cell diseases. Finding molecular mechanisms and the key regulators responsible for globin switching could be helpful to develop effective ways to HbF upregulation. In our prior in silico report, we identified a few factors that are likely to be responsible for globin switching. The goal of this study is to experimentally validate the factors. METHODS: We established K562 cell line with BCL11A knock down leading to increase in HBG1/2 using CRISPR/Cas9 system...

OBJECTIVE: To investigate the efficacy of roxadustat in hemodialysis patients with erythropoietin (EPO) hypo-responsive anemia. MATERIALS AND METHODS: This retrospective study included 55 hemodialysis patients with erythropoietin hypo-responsive anemia at the First Affiliated Hospital of Chongqing Medical University from January to December 2020. We observed their hemoglobin (Hb) changes, inflammatory factors, and adverse reactions before and after 12 weeks of roxadustat treatment...

BACKGROUND: Guidelines recommend deintensifying hypoglycemia-causing medications for older adults with diabetes whose hemoglobin A1c is below their individualized target, but this rarely occurs in practice. OBJECTIVE: To understand physicians' decision-making around deintensifying diabetes treatment. DESIGN: National physician survey. PARTICIPANTS: US physicians in general medicine, geriatrics, or endocrinology providing outpatient diabetes care...

BACKGROUND: Dipeptidyl peptidase-4 inhibitors have limited efficacy in improving glycemic control for obese Japanese patients with type 2 diabetes mellitus. Sodium-glucose co-transporter 2 inhibitors are recommended for use in patients with type 2 diabetes with obesity. Nevertheless, there has been no previously published study on the effect of switching from dipeptidyl peptidase-4 inhibitors to sodium-glucose co-transporter 2 inhibitors on the systemic and organic effects in obese Japanese patients with type 2 diabetes...

AIMS/INTRODUCTION: This study evaluated the effects of the Medtronic MiniMed 770G hybrid closed-loop system on glycemic control and psychological aspects in persons with type 1 diabetes mellitus. MATERIALS AND METHODS: This 3-month prospective observational study included 22 participants with type 1 diabetes mellitus who used the Medtronic MiniMed 640G predictive low-glucose suspend system and were switched to the 770G system. Time in the range of 70-180 mg/dL and glycated hemoglobin levels were evaluated; satisfaction, emotional distress and quality of life were assessed using self-reported questionnaires, including the Diabetes Treatment Satisfaction Questionnaire Status, Problem Area in Diabetes and Diabetes Therapy-Related Quality of Life...

In humans, specific aberrations in β-globin results in sickle cell disease and β -thalassemia, symptoms of which can be ameliorated by increased expression of fetal globin (HbF). Two recent CRISPR-Cas9 screens, centered on ∼1500 annotated sequence-specific DNA binding proteins and performed in a human erythroid cell line that expresses adult hemoglobin, uncovered four groups of candidate regulators of HbF gene expression. They are (1) members of the nucleosome remodeling and deacetylase (NuRD) complex proteins that are already known for HbF control; (2) seven C2H2 zinc finger (ZF) proteins, including some (ZBTB7A and BCL11A) already known for directly silencing the fetal γ-globin genes in adult human erythroid cells; (3) a few other transcription factors of different structural classes that might indirectly influence HbF gene expression; and (4) DNA methyltransferase 1 (DNMT1) that maintains the DNA methylation marks that attract the MBD2-associated NuRD complex to DNA as well as associated histone H3 lysine 9 methylation...

OBJECTIVE: We aimed to investigate the evolution of weight, lipid profiles, and glucose homeostasis among virally-suppressed people living with HIV (PLWH) who switched to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). METHODS: PLWH with viral suppression who switched to BIC/FTC/TAF between October 2019 and May 2021 were followed for 96 weeks to examine the change of weight, lipid profiles (total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG)), and glycated hemoglobin (HbA1c) levels...

Dolutegravir (DTG), an integrase strand transfer inhibitor is currently the recommended first and second line anti-retroviral therapy (ART) anchor agent by the World Health Organization due to its favorable side effect profile, high efficacy and genetic barrier to resistance.Despite its very good side effect profile, there have been multiple case reports of ART experienced patients developing hyperglycemia within weeks to a few months after switching to DTG preceded by weight loss. At population level, however, DTG as well as other integrase inhibitors have been demonstrated to have a reduced risk of incident diabetes mellitus (T2DM) compared to other HIV drug classes...

Myelodysplastic syndromes and myeloproliferative neoplasms both represent hematologic diseases associated with bone marrow failure often resulting in anemia. For those patients, transfusion of red blood cell (RBC) units is essential but results in iron overload (IOL) that may affect various organ functions. Therefore, iron chelation therapy plays a major role in anemic patients, not only because it reduces IOL, but also because it may improve hematopoietic function by increasing hemoglobin or diminishing the requirement for RBC transfusions...

Executive function and processing speed difficulties are observed in children living with sickle cell anemia (SCA). The influence of processing speed on executive function is not well understood. We recruited 59 children living with SCA and 24 matched controls aged 8-18 years between 2010 and 2016 from clinics in the UK. Children completed tests in processing speed and cognitive flexibility, subdomains of executive function. MRI scans were conducted within one year of testing; oxygen saturation was obtained on the day of testing...