The secreted lymphangiogenic factor CCBE1 is essential for fetal liver erythropoiesis.

The secreted protein CCBE1 is required for lymphatic vessel growth in fish and mice, and mutations in the CCBE1 gene cause Hennekam syndrome, a primary human lymphedema. Here we show that loss of CCBE1 also confers severe anemia in midgestation mouse embryos due to defective definitive erythropoiesis. Fetal liver erythroid precursors of Ccbe1 null mice exhibit reduced proliferation and increased apoptosis. Colony-forming assays and hematopoietic reconstitution studies suggest that CCBE1 promotes fetal liver erythropoiesis cell nonautonomously. Consistent with these findings, Ccbe1(lacZ) reporter expression is not detected in hematopoietic cells and conditional deletion of Ccbe1 in hematopoietic cells does not confer anemia. The expression of the erythropoietic factors erythropoietin and stem cell factor is preserved in CCBE1 null embryos, but erythroblastic island (EBI) formation is reduced due to abnormal macrophage function. In contrast to the profound effects on fetal liver erythropoiesis, postnatal deletion of Ccbe1 does not confer anemia, even under conditions of erythropoietic stress, and EBI formation is normal in the bone marrow of adult CCBE1 knockout mice. Our findings reveal that CCBE1 plays an essential role in regulating the fetal liver erythropoietic environment and suggest that EBI formation is regulated differently in the fetal liver and bone marrow.

[1]  Luca Pinello,et al.  Combinatorial assembly of developmental stage-specific enhancers controls gene expression programs during human erythropoiesis. , 2012, Developmental cell.

[2]  Lei Ding,et al.  Endothelial and perivascular cells maintain haematopoietic stem cells , 2011, Nature.

[3]  Harvey F Lodish,et al.  From stem cell to red cell: regulation of erythropoiesis at multiple levels by multiple proteins, RNAs, and chromatin modifications. , 2011, Blood.

[4]  J. Korving,et al.  CCBE1 Is Essential for Mammalian Lymphatic Vascular Development and Enhances the Lymphangiogenic Effect of Vascular Endothelial Growth Factor-C In Vivo , 2011, Circulation research.

[5]  Satoru Takahashi,et al.  c-Maf plays a crucial role for the definitive erythropoiesis that accompanies erythroblastic island formation in the fetal liver. , 2011, Blood.

[6]  M. Shibuya,et al.  VEGFR-3 ligand-binding and kinase activity are required for lymphangiogenesis but not for angiogenesis , 2010, Cell Research.

[7]  S. Mansour,et al.  Linkage and sequence analysis indicate that CCBE1 is mutated in recessively inherited generalised lymphatic dysplasia , 2010, Human Genetics.

[8]  R. Hennekam,et al.  Mutations in CCBE1 cause generalized lymph vessel dysplasia in humans , 2009, Nature Genetics.

[9]  S. Heck,et al.  Resolving the distinct stages in erythroid differentiation based on dynamic changes in membrane protein expression during erythropoiesis , 2009, Proceedings of the National Academy of Sciences.

[10]  Jeroen Bussmann,et al.  ccbe1 is required for embryonic lymphangiogenesis and venous sprouting , 2009, Nature Genetics.

[11]  J. Hirschhorn,et al.  Supporting Online Material Materials and Methods Figs. S1 to S10 Tables S1 to S7 References Human Fetal Hemoglobin Expression Is Regulated by the Developmental Stage-specific Repressor Bcl11a , 2022 .

[12]  N. Mohandas,et al.  Erythroblastic islands: niches for erythropoiesis. , 2008, Blood.

[13]  J. Bieker,et al.  The erythroblastic island. , 2008, Current topics in developmental biology.

[14]  B. Braam,et al.  Mechanisms of Disease: erythropoietin resistance in patients with both heart and kidney failure , 2008, Nature Clinical Practice Nephrology.

[15]  Saijuan Chen,et al.  Disruption of palladin leads to defects in definitive erythropoiesis by interfering with erythroblastic island formation in mouse fetal liver. , 2007, Blood.

[16]  S. Moestrup,et al.  The macrophage CD163 surface glycoprotein is an erythroblast adhesion receptor. , 2007, Blood.

[17]  A. Bhandoola,et al.  Deletion of the developmentally essential gene ATR in adult mice leads to age-related phenotypes and stem cell loss. , 2007, Cell stem cell.

[18]  M. Baron,et al.  Maturation and enucleation of primitive erythroblasts during mouse embryogenesis is accompanied by changes in cell-surface antigen expression. , 2007, Blood.

[19]  L. Peters,et al.  Absence of Erythroblast Macrophage Protein (Emp) Leads to Failure of Erythroblast Nuclear Extrusion* , 2006, Journal of Biological Chemistry.

[20]  N. Mohandas,et al.  Targeted Gene Deletion Demonstrates that Cell Adhesion Molecule ICAM-4 is Critical for Erythroblastic Island Formation , 2006 .

[21]  Masato Koike,et al.  Phosphatidylserine-dependent engulfment by macrophages of nuclei from erythroid precursor cells , 2005, Nature.

[22]  R. Paulson,et al.  BMP4 and Madh5 regulate the erythroid response to acute anemia. , 2005, Blood.

[23]  K. Burnand,et al.  Milroy disease and the VEGFR-3 mutation phenotype , 2005, Journal of Medical Genetics.

[24]  T. Graf,et al.  Assessing the role of hematopoietic plasticity for endothelial and hepatocyte development by non-invasive lineage tracing , 2004, Development.

[25]  Jeffrey Malik,et al.  Yolk sac-derived primitive erythroblasts enucleate during mammalian embryogenesis. , 2004, Blood.

[26]  J. Partanen,et al.  Vascular endothelial growth factor C is required for sprouting of the first lymphatic vessels from embryonic veins , 2004, Nature Immunology.

[27]  R. Hennekam,et al.  Lymphedema-lymphangiectasia-mental retardation (Hennekam) syndrome: a review. , 2002, American journal of medical genetics.

[28]  S. Nagata,et al.  Requirement of DNase II for definitive erythropoiesis in the mouse fetal liver. , 2001, Science.

[29]  K. Devriendt,et al.  Congenital hereditary lymphedema caused by a mutation that inactivates VEGFR3 tyrosine kinase. , 2000, American journal of human genetics.

[30]  H. Lodish,et al.  Fetal Anemia and Apoptosis of Red Cell Progenitors in Stat5a−/−5b−/− Mice A Direct Role for Stat5 in Bcl-XL Induction , 1999, Cell.

[31]  M. Koury,et al.  Erythropoietin retards DNA breakdown and prevents programmed death in erythroid progenitor cells. , 1990, Science.

[32]  M. Bessis.  [Erythroblastic island, functional unity of bone marrow]. , 1958, Revue d'hematologie.