title: CD9 is associated with leukemia inhibitory factor-mediated maintenance of embryonic stem cells.
abstract: Mouse embryonic stem (ES) cells can proliferate indefinitely in an undifferentiated state in the presence of leukemia inhibitory factor (LIF), or differentiate into all three germ layers upon removal of this factor. To determine cellular factors associated with self-renewal of undifferentiated ES cells, we used polymerase chain reaction-assisted cDNA subtraction to screen genes that are expressed in undifferentiated ES cells and down-regulated after incubating these cells in a differentiation medium without LIF for 48 h. The mRNA expression of a tetraspanin transmembrane protein, CD9, was high in undifferentiated ES cells and decreased shortly after cell differentiation. An immunohistochemical analysis confirmed that plasma membrane-associated CD9 was expressed in undifferentiated ES cells but low in the differentiated cells. Addition of LIF to differentiating ES cells reinduced mRNA expression of CD9, and CD9 expression was accompanied with a reappearance of undifferentiated ES cells. Furthermore, activation of STAT3 induced the expression of CD9, indicating the LIF/STAT3 pathway is critical for maintaining CD9 expression. Finally, addition of anti-CD9 antibody blocked ES cell colony formation and reduced cell viability. These results indicate that CD9 may play a role in LIF-mediated maintenance of undifferentiated ES cells.
authors.affiliation: Department of Pathology, Program in Stem Cell Biology, Shands Cancer Center, University of Florida College of Medicine, Gainesville, FL 32610, USA.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Oka
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tagoku
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Russell
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nakano
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamazaki
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Meyer
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokota
authors.forename: Naohiro
authors.initials: N
authors.lastname: Terada
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology*; D006131:Growth Inhibitors / Q000378:metabolism*; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000378:metabolism*; D008562:Membrane Glycoproteins; D051379:Mice; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D053495:Osteopontin; D016133:Polymerase Chain Reaction; D011419:Propidium / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology; D060245:Tetraspanin 29; D013997:Time Factors
chemical_list: D015703:Antigens, CD; C554870:Cd9 protein, mouse; D018076:DNA, Complementary; D006131:Growth Inhibitors; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D008222:Lymphokines; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D060245:Tetraspanin 29; D053495:Osteopontin; D011419:Propidium