Secretome of the preimplantation human embryo by bottom-up label-free proteomics

Abstract

A bottom-up label-free mass spectrometric proteomic strategy was used to analyse the protein profiles of the human embryonic secretome. Culture media samples used for embryonic culture of patients undergoing intracytoplasmic sperm injection cycles were selected as a test case for this exploratory proof-of-principle study. The media were stored after embryo transfer and then pooled into positive (n = 8) and negative (n = 8) implantation groups. The absolute quantitative bottom-up technique employed a multidimensional protein identification technology based on separation by nano-ultra-high pressure chromatography and identification via tandem nano-electrospray ionization mass spectrometry with data-independent scanning in a hydrid QqTOF mass spectrometer. By applying quantitative bottom-up proteomics, unique proteins were found exclusively in both the positive- and negative-implantation groups, which suggest that competent embryos express and secrete unique biomarker proteins into the surrounding culture medium. The selective monitoring of these possible secretome biomarkers could make viable procedures using single-embryo transfer.

Protein expression in human cumulus cells as an indicator of blastocyst formation and pregnancy success

“…Non-invasive approaches for embryonic development potential have the advantages of increasing the knowledge of embryo physiology, therefore allowing the development of methods to predict developmental competence and viability [14]. These approaches include genomic and proteomic profiling and analytical examination of the embryonic metabolome [13,[15][16][17][18][19][20].…”

Proteomic profile of maternal-aged blastocoel fluid suggests a novel role for ubiquitin system in blastocyst quality

“…Proteins up-and downregulated are indicated in black and dark gray, respectively. Proteins which are present at levels not statistically different between groups A and B are indicated in light gray below the horizontal threshold line [49], as the most represented proteins in the secretome of the preimplantation human embryo able to predict positive pregnancy outcome [54]. Moreover, according to a recent observation describing the important role of histone H2A variants (H2A.X, H2A.Z and macroH2A) in genome remodeling after fertilization [55] and preimplantation embryo development [56], our study reveals that blastocoel fluid of aged woman undergoes a global change in histone composition, as it contains soluble histones (H2A.X, H2B and H4) that are completely absent in younger women.…”

Recent advances on multidimensional liquid chromatography–mass spectrometry for proteomics: From qualitative to quantitative analysis—A review

“…Label-free approaches realized through MDLC platforms have been widely employed for biomarker discovery [128][129][130][131][132] and PTMs study [128,133]. In fact, the diverse abundance features, together with the algorithms to generate the quantification results present themselves as the most active research field in label-free quantifications.…”