Pharmacologic induction of fetal hemoglobin (HbF) is an effective strategy for treating sickle cell disease (SCD) by ameliorating disease severity. Hydroxyurea is the only FDA-approved agent that induces HbF, but significant non-responders and requirement for frequent monitoring of blood counts for drug toxicity limit clinical usefulness. Therefore, we investigated a novel prodrug conjugate of butyric acid (BA) and δ-aminolevulinate (ALA) as a potential HbF inducing agent, using erythroid precursors and a preclinical β-YAC mouse model. We observed significantly increased γ-globin gene transcription and HbF expression mediated by AN-233 in K562 cells. Moreover, AN-233 stimulated mild heme biosynthesis and inhibited expression of heme-regulated eIF2α kinase involved in silencing γ-globin expression. Studies using primary erythroid precursors generated from sickle peripheral blood mononuclear cells verified the ability of AN-233 to induce HbF, increase histone H3 and H4 acetylation levels at the γ-globin promoter and reduce erythroid precursor sickling by 50%. Subsequent drug treatment of β-YAC transgenic mice confirmed HbF induction in vivo by AN-233 through an increase in the percentage of HbF positive red blood cells and HbF levels measured by flow cytometry. These data support the potential development of AN-233 for the treatment of SCD.
|Journal||Blood Cells, Molecules, and Diseases|
|State||Published - Nov 2019|
Bibliographical noteFunding Information:
This work was funded through grants from the National Heart Lung and Blood Institute, HL069234 to BSP and HL111264 to KRP and the National Institute of Diabetes and Digestive and Kidney Diseases, DK100595 to KRP. ARO contributed to experimental design, performed experiments, analyzed data and wrote the manuscript; XZ and BL contributed to primary culture studies and ChIP assay; KRP established the β-YAC transgenic mouse, drug design and revised paper; AN and AR synthesized AN233 and contributed to drug treatment design and writing paper; HX created database and performed statistical data analysis for tissue culture and mouse treatments and edited paper; BSP conceived and designed the study and wrote and revised the manuscript. Authors approve the final version of manuscript.
This work was funded through grants from the National Heart Lung and Blood Institute , HL069234 to BSP and HL111264 to KRP and the National Institute of Diabetes and Digestive and Kidney Diseases , DK100595 to KRP.
- Butyric acid
- Fetal hemoglobin
- β-YAC mice