Dimethyl fumarate increases fetal hemoglobin, provides heme detoxification, and corrects anemia in sickle cell disease
Sriram Krishnamoorthy, Betty Pace, Dipti Gupta, Sarah Sturtevant, Biaoru Li, Levi Makala, Julia Brittain, Nancy Moore, Benjamin F. Vieira, Timothy Thullen, Ivan Stone, Huo Li, William E. Hobbs, David R. Light
Sriram Krishnamoorthy, Betty Pace, Dipti Gupta, Sarah Sturtevant, Biaoru Li, Levi Makala, Julia Brittain, Nancy Moore, Benjamin F. Vieira, Timothy Thullen, Ivan Stone, Huo Li, William E. Hobbs, David R. Light
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Research Article Hematology Inflammation

Dimethyl fumarate increases fetal hemoglobin, provides heme detoxification, and corrects anemia in sickle cell disease

Abstract

Sickle cell disease (SCD) results from a point mutation in the β-globin gene forming hemoglobin S (HbS), which polymerizes in deoxygenated erythrocytes, triggering recurrent painful vaso-occlusive crises and chronic hemolytic anemia. Reactivation of fetal Hb (HbF) expression ameliorates these symptoms of SCD. Nuclear factor (erythroid derived-2)–like 2 (Nrf2) is a transcription factor that triggers cytoprotective and antioxidant pathways to limit oxidative damage and inflammation and increases HbF synthesis in CD34+ stem cell–derived erythroid progenitors. We investigated the ability of dimethyl fumarate (DMF), a small-molecule Nrf2 agonist, to activate γ-globin transcription and enhance HbF in tissue culture and in murine and primate models. 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. Chronic DMF administration in SCD mice induced HbF and increased Nrf2-dependent genes to detoxify heme and limit inflammation. This improved hematological parameters, reduced plasma-free Hb, and attenuated inflammatory markers. Chronic DMF administration to nonanemic primates increased γ-globin mRNA in BM and HbF protein in rbc. DMF represents a potential therapy for SCD to induce HbF and augment vasoprotection and heme detoxification.

Authors

Sriram Krishnamoorthy, Betty Pace, Dipti Gupta, Sarah Sturtevant, Biaoru Li, Levi Makala, Julia Brittain, Nancy Moore, Benjamin F. Vieira, Timothy Thullen, Ivan Stone, Huo Li, William E. Hobbs, David R. Light

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Figure 4

DMF increases Nrf2 occupancy at both the ARE of γ-globin and the LCR-HS2 sites.

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DMF increases Nrf2 occupancy at both the ARE of γ-globin and the LCR-HS2...
ChIP assays were performed with KU812 cells treated for 48 hours with 200 μM DMF in Iscove modified Dulbecco buffer (IMDM) compared with IMDM-treated control cells (UT). Enrichment of chromatin DNA precipitated from isolated KU812 erythroleukemia cell nuclei was detected by qPCR following precipitation with a specific anti-Nrf2 antibody (Nrf2), a nonspecific control antibody (IgG), or an antibody to the ubiquitous TATA-binding transcription factor TFIID. (A) Occupancy of the γ-globin promoters ARE by Nrf2 and TFIID in untreated and DMF-treated cells (n = 3–4). (B) Nrf2 and TFIID occupancy of a negative control region (G-CRE) located at –1,222 bp in Gγ-globin promoter following either Nrf2 or TFIID precipitation (n = 3–4). Nrf2 and TFIID occupancy of the locus control region (LCR) DNase hypersensitivity sites (HS) for (C) LCR-HS2 and (D) LCR-HS3 (n = 3–4 for both the panels) were also analyzed (n = 3–4 for both panels). Enrichment of DNA in untreated nonspecific control IgG precipitated samples was used as control, and qPCR data were analyzed using the ΔΔCt method to calculate the fold chromatin enrichment for each site. Results in each panel are reported as mean ± SEM. All P values calculated with student t test, 2-tailed (**P < 0.01).