Endogenous Siderophore 2,5-Dihydroxybenzoic Acid Deficiency Promotes Anemia and Splenic Iron Overload in Mice

Abstract

Eukaryotes produce a siderophore-like molecule via a remarkably conserved biosynthetic pathway. 3-OH butyrate dehydrogenase (BDH2), a member of the short-chain dehydrogenase (SDR) family of reductases, catalyzes a rate-limiting step in the biogenesis of the mammalian siderophore 2,5-dihydroxybenzoic acid (2,5-DHBA). Depletion of the mammalian siderophore by inhibiting expression of bdh2 results in abnormal accumulation of intracellular iron and mitochondrial iron deficiency in cultured mammalian cells, as well as in yeast cells and zebrafish embryos We disrupted murine bdh2 by homologous recombination to analyze the effect of bdh2 deletion on erythropoiesis and iron metabolism. bdh2 null mice developed microcytic anemia and tissue iron overload, especially in the spleen. Exogenous supplementation with 2,5-DHBA alleviates splenic iron overload in bdh2 null mice. Additionally, bdh2 null mice exhibit reduced serum iron. Although BDH2 has been proposed to oxidize ketone bodies, we found that BDH2 deficiency did not alter ketone body metabolism in vivo. In sum, our findings demonstrate a key role for BDH2 in erythropoiesis.

ACKNOWLEDGMENTS

We thank Barry Paw for providing protocols, Alan Tartakoff, Robert B. Petersen, and Dave Goetz for editorial assistance, Gangarao Davuluri for help with mouse experimentation, and Vivian Yee and Vijay Kumar for expert advice on the structure of mutant BDH2. We also thank anonymous reviewer 2 for suggestions that significantly improved the manuscript.

This work is supported by K01CA113838, R01DK081395, and Case Western Reserve University startup funds to L.D. L.D. is also a recipient of career developmental awards from the March of Dimes and American Society of Hematology.