title: A Systems Approach Identifies Essential FOXO3 Functions at Key Steps of Terminal Erythropoiesis.
abstract: Circulating red blood cells (RBCs) are essential for tissue oxygenation and homeostasis. Defective terminal erythropoiesis contributes to decreased generation of RBCs in many disorders. Specifically, ineffective nuclear expulsion (enucleation) during terminal maturation is an obstacle to therapeutic RBC production in vitro. To obtain mechanistic insights into terminal erythropoiesis we focused on FOXO3, a transcription factor implicated in erythroid disorders. Using an integrated computational and experimental systems biology approach, we show that FOXO3 is essential for the correct temporal gene expression during terminal erythropoiesis. We demonstrate that the FOXO3-dependent genetic network has critical physiological functions at key steps of terminal erythropoiesis including enucleation and mitochondrial clearance processes. FOXO3 loss deregulated transcription of genes implicated in cell polarity, nucleosome assembly and DNA packaging-related processes and compromised erythroid enucleation. Using high-resolution confocal microscopy and imaging flow cytometry we show that cell polarization is impaired leading to multilobulated Foxo3-/- erythroblasts defective in nuclear expulsion. Ectopic FOXO3 expression rescued Foxo3-/- erythroblast enucleation-related gene transcription, enucleation defects and terminal maturation. Remarkably, FOXO3 ectopic expression increased wild type erythroblast maturation and enucleation suggesting that enhancing FOXO3 activity may improve RBCs production. Altogether these studies uncover FOXO3 as a novel regulator of erythroblast enucleation and terminal maturation suggesting FOXO3 modulation might be therapeutic in disorders with defective erythroid maturation.
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Developmental and Stem Cell Biology Multidisciplinary Training Area, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Raymond
authors.initials: R
authors.lastname: Liang
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Genís
authors.initials: G
authors.lastname: Campreciós
authors.affiliation: Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Yan
authors.initials: Y
authors.lastname: Kou
authors.affiliation: Department of Pediatrics, Center for Pediatric Biomedical Research,University of Rochester Medical Center, Rochester, New York, United States of America.
authors.forename: Kathleen
authors.initials: K
authors.lastname: McGrath
authors.affiliation: Department of Cell and Molecular Biology, Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Roberta
authors.initials: R
authors.lastname: Nowak
authors.affiliation: Department of Pediatrics, Center for Pediatric Biomedical Research,University of Rochester Medical Center, Rochester, New York, United States of America.
authors.forename: Seana
authors.initials: S
authors.lastname: Catherman
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Carolina L
authors.initials: CL
authors.lastname: Bigarella
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Pauline
authors.initials: P
authors.lastname: Rimmelé
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Merlin Nithya
authors.initials: MN
authors.lastname: Gnanapragasam
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Developmental and Stem Cell Biology Multidisciplinary Training Area, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: James J
authors.initials: JJ
authors.lastname: Bieker
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Papatsenko
authors.affiliation: Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Avi
authors.initials: A
authors.lastname: Ma'ayan
authors.affiliation: Department of Cell and Regenerative Biology, UW-Madison Blood Research Program, University of Wisconsin, Madison, Wisconsin, United States of America.
authors.forename: Emery
authors.initials: E
authors.lastname: Bresnick
authors.affiliation: Department of Cell and Molecular Biology, Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Velia
authors.initials: V
authors.lastname: Fowler
authors.affiliation: Department of Pediatrics, Center for Pediatric Biomedical Research,University of Rochester Medical Center, Rochester, New York, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Palis
authors.affiliation: Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Developmental and Stem Cell Biology Multidisciplinary Training Area, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Department of Medicine, Division of Hematology, Oncology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Saghi
authors.initials: S
authors.lastname: Ghaffari
mesh_terms: D000818:Animals; D001343:Autophagy / Q000235:genetics; D001854:Bone Marrow Cells / Q000378:metabolism; D016764:Cell Polarity / Q000235:genetics; D004900:Erythroblasts / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D004920:Erythropoiesis / Q000235:genetics*; D005434:Flow Cytometry; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D006706:Homeostasis; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D049490:Systems Biology
chemical_list: D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C474033:FoxO3 protein, mouse