title: Synchronous regulation of the determinants of endometrial receptivity to interleukin 1 at key stages of early embryo implantation in vivo.
abstract: OBJECTIVE
  To investigate the expression kinetics of interleukin-1 receptors (IL-1R), receptor antagonist (IL-1RN), and monocyte chemotactic protein 1 (MCP-1) throughout early gestation in mice.
  
  
  METHODS
  Assessment of IL-1R, IL-1RN, and MCP-1 throughout early pregnancy.
  
  
  METHODS
  Reproduction laboratory.
  
  
  METHODS
  B6C3F1 female mice bred with fertile males of the same strain.
  
  
  METHODS
  Collection of endometrial tissue at necropsy from nonimplanted and implanted sites.
  
  
  METHODS
  IL-1R, IL-1RN, and MCP-1 mRNA expression by quantitative reverse-transcription polymerase chain reaction and protein expression by enzyme-linked immunosorbent assay and immunohistochemistry.
  
  
  RESULTS
  The expression of the signaling IL-1R1 significantly increased in the first 2 days of gestation, which corresponded to the inflammatory-like period triggered by the seminal fluid, before increasing again at the implantation window and lasting throughout embryo implantation. The expression of inhibitory IL-1R2 and IL-1RN concomitantly increased during gestational days 1-2 but remained low, particularly within the embryo implantation sites and throughout the implantation period. The expression of MCP-1 significantly increased only at the embryo implantation sites and showed a significant positive correlation with IL-1R1 expression.
  
  
  CONCLUSIONS
  Our data identified for the first time synchronous changes in endometrial IL-1R throughout early gestation in vivo and point to a deep modulation of endometrial receptivity to IL-1 by embryo-driven signals. This may play a key role in the creation of a receptive phenotype in the maternal endometrium and represent a key mechanism underlying embryo implantation.
authors.affiliation: Endocrinologie de la Reproduction, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d'Assise, Faculté de Médecine, Université Laval, Montreal, Quebec, Canada.
authors.forename: Amélie
authors.initials: A
authors.lastname: Bourdiec
authors.affiliation: Endocrinologie de la Reproduction, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d'Assise, Faculté de Médecine, Université Laval, Montreal, Quebec, Canada.
authors.forename: Valéry
authors.initials: V
authors.lastname: Martel
authors.affiliation: Endocrinologie de la Reproduction, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d'Assise, Faculté de Médecine, Université Laval, Montreal, Quebec, Canada; Département d'Obstétrique, Gynécologie et Reproduction, Faculté de Médecine, Université Laval, Montreal, Quebec, Canada. Electronic address: ali.akoum@crsfa.ulaval.ca.
authors.forename: Ali
authors.initials: A
authors.lastname: Akoum
mesh_terms: D000818:Animals; D010064:Embryo Implantation / Q000502:physiology*; D004717:Endometrium / Q000502:physiology*; D005260:Female; D053590:Interleukin 1 Receptor Antagonist Protein / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism*; D051379:Mice; D011247:Pregnancy; D054390:Receptors, CCR2 / Q000378:metabolism*; D053573:Receptors, Interleukin-1 Type I / Q000378:metabolism*
chemical_list: D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D054390:Receptors, CCR2; D053573:Receptors, Interleukin-1 Type I
keywords: Early gestation; embryo implantation; endometrium; interleukin-1