Hemozoin produced by mammals confers heme tolerance

eLife

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[1] Department of Animal and Avian Sciences, University of Maryland, College Park, United States;Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, United States;Department of Medicine, University of Utah School of Medicine, Salt Lake City, United States;Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, United States;Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States;Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan;Tsukuba Research Center for Energy Materials Science, University of Tsukaba, Tsukaba, Japan;Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, United States;NHGRI Embryonic Stem Cell and Transgenic Mouse Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, United States;RIKEN SPring-8 Center, Sayo, Hyogo, Japan;

关键词: heme;    anemia;    iron;    hemozoin;    macrophages;    lysosome;    Mouse;   

DOI  :  10.7554/eLife.49503

来源: publisher

【 摘 要 】

10.7554/eLife.49503.001Free heme is cytotoxic as exemplified by hemolytic diseases and genetic deficiencies in heme recycling and detoxifying pathways. Thus, intracellular accumulation of heme has not been observed in mammalian cells to date. Here we show that mice deficient for the heme transporter SLC48A1 (also known as HRG1) accumulate over ten-fold excess heme in reticuloendothelial macrophage lysosomes that are 10 to 100 times larger than normal. Macrophages tolerate these high concentrations of heme by crystallizing them into hemozoin, which heretofore has only been found in blood-feeding organisms. SLC48A1 deficiency results in impaired erythroid maturation and an inability to systemically respond to iron deficiency. Complete heme tolerance requires a fully-operational heme degradation pathway as haplo insufficiency of HMOX1 combined with SLC48A1 inactivation causes perinatal lethality demonstrating synthetic lethal interactions between heme transport and degradation. Our studies establish the formation of hemozoin by mammals as a previously unsuspected heme tolerance pathway.

【 授权许可】

CC BY