Antibodies against the erythroferrone N-terminal domain prevent hepcidin suppression and ameliorate murine thalassemia

Arezes, J; Foy, N; McHugh, K; Quinkert, D; Benard, S; Sawant, A; Frost, JN; Armitage, AE; Pasricha, SR; Lim, PJ; Tam, MS; Lavallie, E; Pittman, DD; Cunningham, O; Lambert, M; Murphy, JE; Draper, SJ; Jasuja, R; Drakesmith, H

Author(s): Arezes, J; Foy, N; McHugh, K; Quinkert, D; Benard, S; Sawant, A; Frost, JN; Armitage, AE; Pasricha, SR; Lim, PJ; Tam, MS; Lavallie, E; Pittman, DD; Cunningham, O; Lambert, M; Murphy, JE; Draper, SJ; Jasuja, R; Drakesmith, H;
Details: Publication Year 2020-02-20,Volume 135,Issue #8,Page 547-557
Journal Title: Blood
Publication Type: Journal Article
Abstract: Erythroferrone (ERFE) is produced by erythroblasts in response to erythropoietin (EPO) and acts in the liver to prevent hepcidin stimulation by BMP6. Hepcidin suppression allows for the mobilization of iron to the bone marrow for the production of red blood cells. Aberrantly high circulating ERFE in conditions of stress erythropoiesis, such as in patients with beta-thalassemia, promotes the tissue iron accumulation that substantially contributes to morbidity in these patients. Here we developed antibodies against ERFE to prevent hepcidin suppression and to correct the iron loading phenotype in a mouse model of beta-thalassemia [Hbb(th3/+) mice] and used these antibodies as tools to further characterize ERFE's mechanism of action. We show that ERFE binds to BMP6 with nanomolar affinity and binds BMP2 and BMP4 with somewhat weaker affinities. We found that BMP6 binds the N-terminal domain of ERFE, and a polypeptide derived from the N terminus of ERFE was sufficient to cause hepcidin suppression in Huh7 hepatoma cells and in wild-type mice. Anti-ERFE antibodies targeting the N-terminal domain prevented hepcidin suppression in ERFE-treated Huh7 cells and in EPO-treated mice. Finally, we observed a decrease in splenomegaly and serum and liver iron in anti-ERFE-treated Hbb(th3/+) mice, accompanied by an increase in red blood cells and hemoglobin and a decrease in reticulocyte counts. In summary, we show that ERFE binds BMP6 directly and with high affinity, and that antibodies targeting the N-terminal domain of ERFE that prevent ERFE-BMP6 interactions constitute a potential therapeutic tool for iron loading anemias.
Publisher: ASH
Research Division(s): Population Health And Immunity
PubMed ID: 31899794
Link To PubMed Central Version: http://www.ncbi.nlm.nih.gov/pmc/articles/pmc7046598/
Publisher's Version: https://doi.org/10.1182/blood.2019003140
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2020-05-04 09:07:13

Last Modified: 2020-05-04 10:22:06