title: Possible roles of mmu-miR-141 in the endometrium of mice in early pregnancy following embryo implantation.
abstract: OBJECTIVE
  Embryo implantation is directly affected by genes related to uterine receptivity. Studies have demonstrated the important roles of miRNAs in the regulation of gene expression. Our early miRNA chip analyses revealed that the mmu-miR-141 expression in endometrial tissue is lower after embryo implantation than before it. However, the possible roles of miR-141 in embryo implantation have not yet been elucidated. Here, mmu-miR-141 was designed to detect the expression and role of miR-141 in the endometria of mice in early pregnancy following embryo implantation.
  
  
  METHODS
  Real-time PCR and in-situ hybridization were used to study mmu-miR-141 expression in mouse uterus. Cell proliferation was detected by tetrazolium dye (MTT) assay and flow cytometry. Real-time PCR and Western blot analysis were used to confirm the mRNA and protein levels of phosphatase and tensin homolog (PTEN) to determine whether it was the target gene of mmu-miR-141. Enhanced green fluorescent protein (EGFP) fluorescence reporter vector analysis was also performed. A functional study was performed by injecting mice uteri with mmu-miR-141 inhibitor or mimic vectors.
  
  
  RESULTS
  mmu-miR-141 expression was lower on day 6 (D6) than day 4 (D4) and could be increased by progesterone. Reduced mmu-miR-141 could decrease the proliferation activity of stromal cells and promote apoptosis. Upregulation of mmu-miR-141 inhibited PTEN protein expression but downregulation of mmu-miR-141 increased it, while the mRNA level remained unchanged. EGFP fluorescence reporter vector analysis showed that miR-141 targets the 3'-untranslated region of the PTEN mRNA. In addition, when the physiological mmu-miR-141 level was altered on D2 by injecting with inhibitor or mimic, the embryo implantation sites were significantly decreased on D7.
  
  
  CONCLUSIONS
  This study demonstrated that mmu-miR-141 might influence cell proliferation and apoptosis in the endometrium by negatively regulating PTEN expression, and could also influence the number of embryo implantation sites. mmu-miR-141 plays an essential role in embryo implantation.
authors.affiliation: Laboratory of Reproductive Biology, School of Public Health, Chongqing Medical University, Yuzhong District, Chongqing, PR China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Liu
authors.forename: Rufei
authors.initials: R
authors.lastname: Gao
authors.forename: Xuemei
authors.initials: X
authors.lastname: Chen
authors.forename: Hailing
authors.initials: H
authors.lastname: Zhang
authors.forename: Anshun
authors.initials: A
authors.lastname: Zheng
authors.forename: Dehui
authors.initials: D
authors.lastname: Yang
authors.forename: Yubin
authors.initials: Y
authors.lastname: Ding
authors.forename: Yingxiong
authors.initials: Y
authors.lastname: Wang
authors.forename: Junlin
authors.initials: J
authors.lastname: He
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D040761:Biomimetic Materials / Q000008:administration & dosage / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D010064:Embryo Implantation / Q000187:drug effects; D004717:Endometrium / Q000166:cytology / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007267:Injections; D051379:Mice; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics*; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D011247:Pregnancy; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects
chemical_list: D035683:MicroRNAs; C543718:Mirn141 microRNA, mouse; D051059:PTEN Phosphohydrolase