2'-O-methoxyethyl splice-switching oligos correct splicing from IVS2-745 β-thalassemia patient cells restoring HbA production and chain rebalance

\u3b2-thalassemia is a disorder caused by altered hemoglobin protein synthesis and affects individuals worldwide. Severe forms of the disease, left untreated, can result in death before the age of 3 years (1). The standard of care consists of chronic and costly palliative treatment by blood transfusion combined with iron chelation. This dual approach suppresses anemia and reduces iron-related toxicities in patients. Allogeneic bone marrow transplant is an option, but limited by the availability of a highly compatible HSC donor. While gene therapy is been explored in several trials, its use is highly limited to developed regions with centers of excellence and well-established healthcare systems (2). Hence, there remains a tremendous unmet medical need to develop alternative treatment strategies for \u3b2-thalassemia (3). Occurrence of aberrant splicing is one of the processes that affects \u3b2-globin synthesis in \u3b2-thalassemia. The (C>G) IVS-2-745 is a splicing mutation within intron 2 of the \u3b2-globin gene. It leads to an aberrantly spliced mRNA that incorporates an intron fragment. This results in an in-frame premature termination codon that inhibits \u3b2-globin production. Here, we propose the use of uniform 2'-O-methoxyethyl (2'-MOE) splice switching oligos (SSOs) to reverse this aberrant splicing in the pre-mRNA. With these lead SSOs we show aberrant to wild type splice switching. This switching leads to an increase of adult hemoglobin (HbA) up to 80% in erythroid cells from patients with the IVS-2-745 mutation. Furthermore, we demonstrate a restoration of the balance between \u3b2-like- and \u3b1-globin chains, and up to an 87% reduction in toxic \u3b1-heme aggregates. While examining the potential benefit of 2'-MOE-SSOs in a mixed sickle-thalassemic phenotypic setting, we found reduced HbS synthesis and sickle cell formation due to HbA induction. In summary, 2'-MOE-SSOs are a promising therapy for forms of \u3b2-thalassemia caused by mutations leading to aberrant splicing

Studio della pro-epcidina sierica e dello stato del ferro nella talassemia major ed intermedia

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Reversal of cardiac complications by deferiprone and deferoxamine combination therapy in a patient affected by a severe type of juvenile hemochromatosis (JH)

Juvenile hemochromatosis (JH) is a rare autosomal recessive disorder of iron metabolism, genetically heterogeneous. In JH, symptomatic organ involvement occurs as early as the second decade of life. Heart failure and/or arrhythmias are the most frequent causes of death. Phlebotomy is the safest, most effective, and most economic therapeutic approach in hemochromatosis patients but is not indicated during the treatment of severe congestive heart failure with unstable hemodynamic status. The treatment of iron overload in these prohibitive clinical situations has to be carried out using iron chelators. We report a case of heart failure in the setting of unrecognized juvenile hemochromatosis successfully treated by the simultaneous administration of deferoxamine and deferiprone. To our knowledge, this is the first patient affected by JH treated with combined chelation regimen

Mutation analysis of hepcidin and ferroportin genes in Italian prospective blood donors with iron overload

Maintenance of iron balance is essential for humans and requires the coordinate regulation of iron transport into plasma from dietary sources in the duodenum, from recycled senescent red cells in macrophages, and from storage in hepatocytes. Hepcidin, a recently identified antimicrobial peptide produced in the liver, has been shown to play a central role in the homeostatic regulation of iron absorption and distribution [1]. It is a negative regulator of iron absorption in the small intestine and of iron release from macrophages engaged in the recycling of iron senescent erythrocytes [2]. The human hepcidin gene contains three exons that encode a 72-aa precursor (pro-hepcidin) with a characteristic furin cleavage site immediately N-terminal to the 25-aa major hepcidin species found in plasma and urine [3]. Recently, hepcidin has been shown to regulate iron homeostasis by interaction with ferroportin, an iron cellular exporter highly expressed in absorptive enterocytes, macrophages, hepatocytes, and placental cells [4]