title: Compound loss of function of nuclear receptors Tr2 and Tr4 leads to induction of murine embryonic β-type globin genes.
abstract: The orphan nuclear receptors TR2 and TR4 have been shown to play key roles in repressing the embryonic and fetal globin genes in erythroid cells. However, combined germline inactivation of Tr2 and Tr4 leads to periimplantation lethal demise in inbred mice. Hence, we have previously been unable to examine the consequences of their dual loss of function in adult definitive erythroid cells. To circumvent this issue, we generated conditional null mutants in both genes and performed gene inactivation in vitro in adult bone marrow cells. Compound Tr2/Tr4 loss of function led to induced expression of the embryonic εy and βh1 globins (murine counterparts of the human ε- and γ-globin genes). Additionally, TR2/TR4 function is required for terminal erythroid cell maturation. Loss of TR2/TR4 abolished their occupancy on the εy and βh1 gene promoters, and concurrently impaired co-occupancy by interacting corepressors. These data strongly support the hypothesis that the TR2/TR4 core complex is an adult stage-specific, gene-selective repressor of the embryonic globin genes. Detailed mechanistic understanding of the roles of TR2/TR4 and their cofactors in embryonic and fetal globin gene repression may ultimately enhance the discovery of novel therapeutic agents that can effectively inhibit their transcriptional activity and be safely applied to the treatment of β-globinopathies.
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI;
authors.forename: Shuaiying
authors.identifier: http://orcid.org/0000-0001-9104-8517
authors.initials: S
authors.lastname: Cui
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI; Department of Integrative Genomics Tohoku Medical Megabank, Tohoku University, Sendai, Japan;
authors.forename: Osamu
authors.initials: O
authors.lastname: Tanabe
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI;
authors.forename: Michael
authors.initials: M
authors.lastname: Sierant
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI; State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China; and.
authors.forename: Lihong
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Pediatrics and Infectious Diseases, University of Michigan Medical School, Ann Arbor, MI.
authors.forename: Andrew
authors.initials: A
authors.lastname: Campbell
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI;
authors.forename: Kim-Chew
authors.initials: KC
authors.lastname: Lim
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI;
authors.forename: James Douglas
authors.initials: JD
authors.lastname: Engel
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D004622:Embryo, Mammalian / Q000378:metabolism*; D041905:Erythroid Cells / Q000166:cytology* / Q000378:metabolism; D005333:Fetus / Q000378:metabolism*; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D006801:Humans; D019426:Integrases / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D057107:Nuclear Receptor Subfamily 2, Group C, Member 1 / Q000502:physiology*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011987:Receptors, Steroid / Q000502:physiology*; D011988:Receptors, Thyroid Hormone / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism*
chemical_list: C539823:Nr2c1 protein, mouse; C490514:Nr2c2 protein, mouse; D057107:Nuclear Receptor Subfamily 2, Group C, Member 1; D012333:RNA, Messenger; D011987:Receptors, Steroid; D011988:Receptors, Thyroid Hormone; D055544:beta-Globins; C045073:Cre recombinase; D019426:Integrases