title: Cyclin G1 and cyclin G2 are expressed in the periimplantation mouse uterus in a cell-specific and progesterone-dependent manner: evidence for aberrant regulation with Hoxa-10 deficiency.
abstract: Because uterine cell-specific proliferation, differentiation, and apoptosis are differentially regulated during the periimplantation period, we speculated that negative cell cycle regulators are also operative in the uterus during this period. This prompted us to examine the roles of two negative growth-regulatory genes, cyclin G1 and cyclin G2, in the periimplantation mouse uterus. We show that cyclin G1 and cyclin G2 genes are differentially regulated in the uterus during this period (d 1-8 of pregnancy) in a spatiotemporal manner. The results suggest that cyclin G1 is primarily associated with epithelial cell differentiation before implantation and stromal cell proliferation and differentiation during decidualization, whereas cyclin G2 is associated with terminal differentiation and apoptosis of the luminal epithelial and stromal cells at the site of blastocyst after implantation. Pharmacological and genetic studies provide evidence that the expression of cyclin G1, not cyclin G2, is regulated by progesterone via its nuclear receptor. Furthermore, the expression of these genes is aberrantly up-regulated in homeo box A-10 mutant uteri, suggesting that cyclin G1 and cyclin G2 genes act as downstream targets of homeobox A-10 and negatively impact uterine cell proliferation. Collectively, our present and previous studies suggest that negative cell cycle regulators collaborate with growth-promoting regulators in regulating uterine cell-specific proliferation, differentiation, and apoptosis relevant to implantation and decidualization.
authors.affiliation: Division of Reproductive and Developmental Biology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
authors.forename: Limin
authors.initials: L
authors.lastname: Yue
authors.forename: Takiko
authors.initials: T
authors.lastname: Daikoku
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Hou
authors.forename: Meiling
authors.initials: M
authors.lastname: Li
authors.forename: Haibin
authors.initials: H
authors.lastname: Wang
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nojima
authors.forename: Sudhansu K
authors.initials: SK
authors.lastname: Dey
authors.forename: Sanjoy K
authors.initials: SK
authors.lastname: Das
mesh_terms: D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000502:physiology; D002454:Cell Differentiation; D056746:Cyclin G; D056766:Cyclin G1; D056767:Cyclin G2; D016213:Cyclins / Q000235:genetics* / Q000502:physiology; D003656:Decidua / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology; D005801:Genes, Homeobox; D005865:Gestational Age; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology*; D017154:Stromal Cells / Q000166:cytology; D014599:Uterus / Q000737:chemistry* / Q000166:cytology
chemical_list: C534703:Ccng1 protein, mouse; D056746:Cyclin G; D056766:Cyclin G1; D056767:Cyclin G2; D016213:Cyclins; D000080905:Homeobox A10 Proteins; D018398:Homeodomain Proteins; C092119:Hoxa10 protein, mouse; D011374:Progesterone