Expression of TET and 5-HmC in Trophoblast Villi of Women with Normal Pregnancy and with Early Pregnancy Loss

Increasing evidence suggests that epigenetic dysfunction may influence the stability of normal pregnancy. The ten-eleven translocation （TET） family and 5-hydroxymethylcytosine （5-hmC） were found to be linked with epigenetic reprogramming. The present study aimed to examine the expression of the TET family and 5-hmC in the villi of human embryos and compared their expression between normal pregnancy and early pregnancy loss （EPL）. Embryonic villi were collected from normal pregnant women （control） experiencing medical abortion and from EPL patients at gestation ages of 6, 7 and 8 weeks. The mRNAs of TET family were analysed using quantitative polymerase chain reaction （qPCR）, and TET proteins using Western blotting and immunohistochemical analysis. The MethylFlashTM Kit was used to quantify the absolute amount of 5-methylcytosine （5-mC） and 5-hmC. Our results showed that the expression of the TETs and 5-hmC in the normal villus decreased with increasing gestational age. Immunohistochemistry revealed that the TET proteins were expressed in the cytoplasm of trophoblasts and their expression was the highest in the 6-week tissue samples, which was consistent with the qPCR and Western blot results. The expression of TET1, TET2, and TET3 was lower in the villi in EPL group than in normal pregnancy group （P〈0.05 for all）. It was concluded that the TET family and 5-hmC are critical in epigenetic reprogramming of human embryo. The findings also suggest that a deficiency of TETs in the villus might be associated with human EPL.

Do specific ultrasonography features identified at the time of early pregnancy loss predict fetal chromosomal abnormality? e A systematic review and meta-analysis

To investigate the association of specific ultrasonography features identified during the diagnosis of early pregnancy loss(EPL)and abnormal karyotype.This was a systematic review and meta-analysis conducted in accordance with PRISMA criteria.We searched PubMed,Cochrane and Ovid MEDLINE from 1977 to Jan 2017 to identify the articles that described EPL with karyotype and ultrasonography features.Risk differences were pooled to estimate the chromosomal abnormality rates in ultrasonography features,including pre-embryonic,enlarged yolk sac(YS),short crown rump length(CRL),small gestational sac(GS),symmetrical arrested growth embryo,or gestational sac with only a YS.Quality assessment of included studies was performed using Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)checklists for Observational Studies(2007 version).Thirteen studies were included in the meta-analysis.Chromosomal abnormality was more likely to occur in embryonic EPL and enlarged YS.On the other hand,short CRL,small GS,symmetrical arrested growth embryo,or gestational sac with only a YS,were not associated with an increased risk of fetal chromosomal abnormality.Ultrasonography features at the time of diagnosis of EPL have limited predictive value of fetal chromosomal abnormality.

Comparative analysis between endometrial proteomes of pregnant and non-pregnant ewes during the peri-implantation period

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. Result： 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. Conclusion： 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.