Proteomics of the Human First Trimester Chorionic Villi Associated with Anembryonic Pregnancy

In this study, the proteomic approach based on high performance liquid chromatography connected with tandem mass spectrometry (LC-MS/MS) and bioinformatics analysis were applied to identify differentially abundant proteins in chorionic villus samples (CVS) from women with blighted ovum and normal pregnancy. We identified about 600 proteins in the solubilized fraction of CVS. Comparative proteomic analysis revealed differences in the content (Average Normalized Abundances) of 187 proteins in blighted ovum. These included 134 down-regulated proteins and 53 up-regulated proteins. According to bioinformatics analysis these proteins participate in a variety of metabolic processes, including alcohol and tricarboxylic acid metabolism, response to endoplasmic reticulum stress, small molecular catabolic process, cellular respiration, and others. Proteins that demonstrated growing content in blighted ovum were mainly encoded by genes located on chromosomes 7 and 16 whereas proteins which demonstrated reducing abundance were mainly encoded by genes located on chromosomes 1, 2, and 11. We also revealed changes in the content of proteins encoded by genes located on the human chromosome 18; they are involved in apoptotic and drug metabolic processes with an important role in early pregnancy loss. Our pilot results demonstrate the efficiency of the LC-MS/MS approach for detecting the differences at the qualitative and semi-quantitative levels in the protein profiles of the CVS at anembryonic pregnancy compared to normal gestation. We conclude that globally profiled and differentially regulated proteins of CVS are helpful in obtaining molecular insights into biological processes of the pregnancy pathology.