title: Increased expression of HIF2α during iron deficiency-associated megakaryocytic differentiation.
abstract: BACKGROUND
  Iron deficiency is associated with reactive thrombocytosis; however, the mechanisms driving this phenomenon remain unclear. We previously demonstrated that this occurs alongside enhanced megakaryopoiesis in iron-deficient rats, without alterations in the megakaryopoietic growth factors thrombopoietin, interleukin-6, or interleukin-11.
  
  
  OBJECTIVE
  The aim of this study was to evaluate megakaryocyte differentiation under iron deficiency in an in vitro model and to investigate potential genes involved in this process.
  
  
  METHODS
  Human erythroleukemia and megakaryoblastic leukemia cell lines, as well as cord-blood derived hematopoietic stem cells were cultured under iron deficiency. Cell morphology, ploidy, expression of CD41, CD61, and CD42b, and proplatelet formation were assessed in iron-deficient cultures. Polymerase chain reaction arrays were used to identify candidate genes that were verified using real-time polymerase chain reaction. Hypoxia-inducible factor 1, α subunit (HIF2α) protein expression was assessed in bone marrow sections from iron-deficient rats and vascular endothelial growth factor (VEGF)-A in culture supernatants.
  
  
  CONCLUSIONS
  Iron deficiency enhanced megakaryoid features in cell lines, increasing ploidy and initiating formation of proplatelet-like structures. In cord blood cell cultures, iron deficiency increased the percentage of cells expressing megakaryopoietic markers and enhanced proplatelet formation. HIF2α and VEGF were identified as potential pathways involved in this process. HIF2α protein expression was increased in megakaryocytes from iron-deficient rats, and VEGF-A concentration was higher in iron-deficient culture supernatants. Addition of VEGF-A to cell cultures increased percentage expression of megakaryocyte CD41. In conclusion, the data demonstrate that iron deficiency augments megakaryocytic differentiation and proplatelet formation and a potential role of HIF2α in megakaryopoiesis.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.|Christian Doppler Laboratory on Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Jimenez
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.|Christian Doppler Laboratory on Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: V
authors.initials: V
authors.lastname: Khare
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Evstatiev
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Kulnigg-Dabsch
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.|Christian Doppler Laboratory on Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Jambrich
authors.affiliation: Center of Pathophysiology, Infectiology, and Immunology, Institute of Immunology, Medical University of Vienna, Vienna, Austria.|Center of Molecular Medicine, Institute of Pathophysiology and Immunology, Medical University of Graz, Graz, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Strobl
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine III, Medical University of Vienna, Vienna, Austria.|Christian Doppler Laboratory on Molecular Cancer Chemoprevention, Medical University of Vienna, Vienna, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Gasche
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000235:genetics / Q000473:pathology; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D048430:Cell Shape; D004195:Disease Models, Animal; D005312:Fetal Blood / Q000166:cytology; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D008533:Megakaryocytes / Q000378:metabolism* / Q000473:pathology; D010976:Platelet Count; D011003:Ploidies; D051381:Rats; D015398:Signal Transduction; D013922:Thrombocytosis / Q000097:blood* / Q000235:genetics / Q000473:pathology; D034061:Thrombopoiesis; D013997:Time Factors; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D042461:Vascular Endothelial Growth Factor A; D000099162:Endothelial PAS Domain-Containing Protein 1; C467484:VEGFA protein, human
keywords: endothelial PAS domain-containing protein 1; iron deficiency anemia; megakaryocytes; thrombocytosis; thrombopoiesis