{"title":"Rbm38 Deficiency Impairs Erythroid Heme Biosynthesis and Induces Porphyria via Reduced Ferrochelatase Expression.","authors":"Xinshu Xie,Ailing Zou,Lei Zhang,Xuezhen Ma,Yaohui He,Hanqi Liu,Yating Lu,Yexin Yang,Jie Ouyang,Kang Liu,Pengcheng Zhong,Ji Li,ShuQian Xu,Lifang Zhou,Bing Han,Miao Chen,Kaosheng Lv,Dingxiao Zhang,Lu Liu,Yang Mei","doi":"10.1182/blood.2025028783","DOIUrl":null,"url":null,"abstract":"RNA splicing and processing are critical for erythropoiesis, as dysregulation of RNA splicing ultimately disrupts protein synthesis. The RNA-binding protein Rbm38 is highly expressed during terminal erythropoiesis. While in vitro studies have implicated Rbm38 as a key regulator of erythroid differentiation, the landscape of RNA splicing regulated by Rbm38 and its role in terminal erythropoiesis in vivo have not been fully elucidated. Here, we generated whole-body and conditional knockout mouse models for Rbm38 and found that mature red blood cell production was impaired in the bone marrow of Rbm38-deficient mice. Rbm38-/- red blood cells exhibited reduced hemoglobin content and increased susceptibility to oxidative stress-induced hemolysis. These mutant mice also developed microcytic hypochromic anemia, along with dysregulated iron homeostasis. Additionally, they exhibited decreased mitochondrial heme biosynthesis and accumulation of free protoporphyrin (PPIX) in erythrocytes and feces, resembling human erythropoietic protoporphyria (EPP). Mechanistically, Rbm38 regulates the incorporation of ferrous iron (Fe2+) into PPIX to form heme by modulating alternative splicing, mRNA decay, and translation of the porphyrin metabolic enzyme gene Ferrochelatase (Fech). Importantly, enforced expression of Fech largely restored erythroid differentiation defects and ameliorated anemia in Rbm38-/- transplants. We further demonstrated that genetic variants in the human RBM38 gene locus influence PPIX levels in erythrocytes from healthy cohorts. Our findings demonstrate that Rbm38 governs terminal erythropoiesis by orchestrating RNA splicing, stability, and translation during heme biosynthesis.","PeriodicalId":9102,"journal":{"name":"Blood","volume":"77 1","pages":""},"PeriodicalIF":23.1000,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Blood","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1182/blood.2025028783","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"HEMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
RNA splicing and processing are critical for erythropoiesis, as dysregulation of RNA splicing ultimately disrupts protein synthesis. The RNA-binding protein Rbm38 is highly expressed during terminal erythropoiesis. While in vitro studies have implicated Rbm38 as a key regulator of erythroid differentiation, the landscape of RNA splicing regulated by Rbm38 and its role in terminal erythropoiesis in vivo have not been fully elucidated. Here, we generated whole-body and conditional knockout mouse models for Rbm38 and found that mature red blood cell production was impaired in the bone marrow of Rbm38-deficient mice. Rbm38-/- red blood cells exhibited reduced hemoglobin content and increased susceptibility to oxidative stress-induced hemolysis. These mutant mice also developed microcytic hypochromic anemia, along with dysregulated iron homeostasis. Additionally, they exhibited decreased mitochondrial heme biosynthesis and accumulation of free protoporphyrin (PPIX) in erythrocytes and feces, resembling human erythropoietic protoporphyria (EPP). Mechanistically, Rbm38 regulates the incorporation of ferrous iron (Fe2+) into PPIX to form heme by modulating alternative splicing, mRNA decay, and translation of the porphyrin metabolic enzyme gene Ferrochelatase (Fech). Importantly, enforced expression of Fech largely restored erythroid differentiation defects and ameliorated anemia in Rbm38-/- transplants. We further demonstrated that genetic variants in the human RBM38 gene locus influence PPIX levels in erythrocytes from healthy cohorts. Our findings demonstrate that Rbm38 governs terminal erythropoiesis by orchestrating RNA splicing, stability, and translation during heme biosynthesis.
期刊介绍:
Blood, the official journal of the American Society of Hematology, published online and in print, provides an international forum for the publication of original articles describing basic laboratory, translational, and clinical investigations in hematology. Primary research articles will be published under the following scientific categories: Clinical Trials and Observations; Gene Therapy; Hematopoiesis and Stem Cells; Immunobiology and Immunotherapy scope; Myeloid Neoplasia; Lymphoid Neoplasia; Phagocytes, Granulocytes and Myelopoiesis; Platelets and Thrombopoiesis; Red Cells, Iron and Erythropoiesis; Thrombosis and Hemostasis; Transfusion Medicine; Transplantation; and Vascular Biology. Papers can be listed under more than one category as appropriate.