There is a general agreement that pharmacologically mediated stimulation of human γ-globin gene expression and increase of production of fetal hemoglobin (HbF) is a potential therapeutic approach in the experimental therapy of β-thalassemia and sickle cell anemia.
Re-expression of the paralogous γ-globin genes (HBG1/2) could be a universal strategy to ameliorate the severe β-globin disorders sickle cell disease (SCD) and β-thalassemia by induction of fetal hemoglobin (HbF, α<sub>2</sub>γ<sub>2</sub>)<sup>1</sup>.
Induction of fetal hemoglobin (HbF) via clustered regularly interspaced short palindromic repeats/Cas9-mediated disruption of DNA regulatory elements that repress γ-globin gene (HBG1 and HBG2) expression is a promising therapeutic strategy for sickle cell disease (SCD) and β-thalassemia, although the optimal technical approaches and limiting toxicities are not yet fully defined.
Genetic knockout of NRF2 demonstrates its role in developmentally regulated γ-globin gene expression and the ability to control oxidative stress and the phenotypic severity of SCD.
We generated helper-dependent HDAd5/35<sup>++</sup> adenovirus vectors expressing CRISPR/Cas9 for potential hematopoietic stem cells (HSCs) gene therapy of β-thalassemia and sickle cell disease through re-activation of fetal γ-globin expression (HDAd-globin-CRISPR).
Hydroxyurea differentially modulates activator and repressors of γ-globin gene in erythroblasts of responsive and non-responsive patients with sickle cell disease in correlation with Index of Hydroxyurea Responsiveness.
The mechanisms that repress HbF expression and silence γ-globin genes in adults are incompletely characterized and only a single HbF inducer, hydroxyurea, is approved for treatment, and only in patients with sickle cell disease.
Understanding the transcriptional regulation of the globin genes is of particular interest, as reactivating the foetal γ-globin gene alleviates the symptoms of β-thalassaemia and sickle cell anaemia.
DMF recruited Nrf2 to the γ-globin promoters and the locus control region of the β-globin locus in erythroleukemia cells, elevated HbF in SCD donor-derived erythroid progenitors, and reduced hypoxia-induced sickling.
Disorders resulting from mutations in the hemoglobin subunit beta gene (HBB; which encodes β-globin), mainly sickle cell disease (SCD) and β-thalassemia, become symptomatic postnatally as fetal γ-globin expression from two paralogous genes, hemoglobin subunit gamma 1 (HBG1) and HBG2, decreases and adult β-globin expression increases, thereby shifting red blood cell (RBC) hemoglobin from the fetal (referred to as HbF or α2γ2) to adult (referred to as HbA or α2β2) form.
Bone marrow CD34+ cells from three SCD patients were transduced using V5m3-400 or βAS3-FB and compared with mock-transduced SCD or healthy donor CD34+ cells.
Pharmacological induction of the fetal γ globin gene and the consequent formation of HbF (α2/γ2) in adult erythroid cells are one feasible therapeutic strategy for sickle cell disease (SCD) and severe β-thalassemias.
The results indicate that the ability of RN-1 to induce F cells and γ-globin mRNA in SCD mice is similar to that of decitabine, the most powerful fetal hemoglobin-inducing drug known, and greater than that of either TCP or hydroxyurea.
The clinical symptoms of hemoglobin disorders such as β-thalassemia and sickle cell anemia are significantly ameliorated by the persistent expression of γ-globin after birth.
We assessed whether the HbF response of patients with SCD and thalassemia intermedia (TI) to HU correlates with HBG (both γ-globin genes) expression in their cultured erythroid progenitors following exposure to HU.
Enhanced fetal γ-globin synthesis alleviates symptoms of β-globinopathies such as sickle cell disease and β-thalassemia, but current γ-globin-inducing drugs offer limited beneficial effects.
Because forced expression of TR2/TR4 in murine adult erythroid cells paradoxically enhanced fetal γ-globin gene expression in transgenic mice, we wished to determine if forced TR2/TR4 expression in a SCD model mouse would result in elevated HbF synthesis and thereby alleviate the disease phenotype.
Fetal hemoglobin (HbF), encoded by the HBG2 and HBG1 genes, is the best-known genetic modulator of sickle cell anemia, varying dramatically in concentration in the blood of these patients.
We aimed to identify trans-activators of ε- and γ-globin expression and provide new candidate targets for effective treatment of sickle cell disease (SCD) and β-thalassemia through activation of ε- and γ-globin genes in adults.