title: [Uterine macrophages affect embryo implantation via regulating vascular endothelial growth factor A in mice].
abstract: OBJECTIVE
  To investigate the role of endometrial macrophages in embryo implantation and in regulating the expression of vascular endothelial growth factor A (VEGFA) in mouse endometrium during the peri-implantation period.
  
  
  METHODS
  At D3.5 (D0.5 defined as the morning when a vaginal plug was observed), pregnant mice were divided randomly into experimental group, control group and blank group. In the experimental group, the mice were subjected to intrauterine injection of clodronate liposomes on the left side of uterus to eliminate the macrophages, and PBS liposomes on the right side. PBS liposomes and PBS were administered in the control and blank groups, respectively. The uterine tissues were collected on D5.5 and stained with trypan blue to show the implantation sites. Flow cytometry was performed to examine the percentage of F4/80(+) CD11b(+) macrophages macrophages in the uterus. F4/80(+) macrophage population within the endometrium and ovary and changes in VEGFA expression at the implantation and non-implantation sites were examined using immunohistochemistry.
  
  
  RESULTS
  Endometrial F4/80(+) CD11b(+) macrophages macrophages were significantly reduced by 74% following intrauterine injection of clodronate liposomes (P<0.05). The number of macrophages in the ovaries showed no significant difference among the 3 groups. In the experimental group, the left side of the uterine showed imcomplete cavity closure with a lower number of implantation site than the right side (2.20∓1.81 vs 5.10∓1.91, P<0.05). VEGFA expression at the implantation site were significantly decreased in the endometrium on the left side with macrophage suppression as compared with that on the right side (P<0.05).
  
  
  CONCLUSIONS
  Endometrial macrophages appear to modulate uterine receptivity by regulating the expression of VEGFA to affect embryo implantation, suggesting the important role of macrophages in embryo implantation.
authors.affiliation: Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.E-mail: iriswong2013@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Duo
authors.initials: D
authors.lastname: Xie
authors.forename: Mian
authors.initials: M
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Gong
authors.forename: Xiao
authors.initials: X
authors.lastname: Shi
authors.forename: Jin-Yan
authors.initials: JY
authors.lastname: Wei
authors.forename: Song
authors.initials: S
authors.lastname: Quan
mesh_terms: D000818:Animals; D010064:Embryo Implantation; D004717:Endometrium / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D008264:Macrophages / Q000166:cytology*; D051379:Mice; D010053:Ovary / Q000166:cytology; D011247:Pregnancy; D011897:Random Allocation; D014599:Uterus / Q000166:cytology*; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*
chemical_list: D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse