title: Comparative analysis between endometrial proteomes of pregnant and non-pregnant ewes during the peri-implantation period.
abstract: BACKGROUND
  Early pregnancy failure has a profound impact on both human reproductive health and animal production. 2/3 pregnancy failures occur during the peri-implantation period; however, the underlying mechanism(s) remains unclear. Well-organized modification of the endometrium to a receptive state is critical to establish pregnancy. Aberrant endometrial modification during implantation is thought to be largely responsible for early pregnancy loss.
  
  
  RESULTS
  In this study, using well-managed recipient ewes that received embryo transfer as model, we compared the endometrial proteome between pregnant and non-pregnant ewes during implantation period. After embryo transfer, recipients were assigned as pregnant or non-pregnant ewes according to the presence or absence of an elongated conceptus at Day 17 of pregnancy. By comparing the endometrial proteomic profiles between pregnant and non-pregnant ewes, we identified 94 and 257 differentially expressed proteins (DEPs) in the endometrial caruncular and intercaruncular areas, respectively. Functional analysis showed that the DEPs were mainly associated with immune response, nutrient transport and utilization, as well as proteasome-mediated proteolysis.
  
  
  CONCLUSIONS
  These analysis imply that dysfunction of these biological processes or pathways of DEP in the endometrium is highly associated with early pregnancy loss. In addition, many proteins that are essential for the establishment of pregnancy showed dysregulation in the endometrium of non-pregnant ewes. These proteins, as potential candidates, may contribute to early pregnancy loss.
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Haichao
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.|Department of Biochemistry and Molecular, Dalian Medical University, Dalian, 116044 China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Sui
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Kai
authors.initials: K
authors.lastname: Miao
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Lei
authors.initials: L
authors.lastname: An
authors.affiliation: The Key Laboratory for Farm Animal Genetic Resources and Utilization of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agriculture Sciences, Beijing, 100193 China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, China Agricultural University, Beijing, 100193 China.
authors.forename: Zhuocheng
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Min
authors.initials: M
authors.lastname: Guo
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Zhilong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, Agricultural University of Hebei, Baoding, Hebei 071000 People's Republic of China.
authors.forename: Jiqiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Animal Nutrition, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Zhonghong
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Ministry of Agriculture Key Laboratory of Animal Genetics, Breeding and Reproduction, National engineering laboratory for animal breeding, College of Animal Sciences and Technology, China Agricultural University, No.2 Yuanmingyuan Xi Lu, Haidian, Beijing, 100193 China.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Tian
keywords: Early pregnancy loss; Endometrium; Ewe; LC-MS/MS; Proteome