A Proteomic Analysis of Human Follicular Fluid: Comparison between Younger and Older Women with Normal FSH Levels

Abstract

The follicular fluid (FF) is produced during folliculogenesis and contains a variety of proteins that play important roles in follicle development and oocyte maturation. Age-related infertility is usually considered as a problem that can be solved by assisted reproduction technology. Therefore, the identification of novel biomarkers that are linked to reproductive aging is the subject of this study. FF was obtained from healthy younger (20–32 years old) and older (38–42 years old) women undergoing intracytoplasmic sperm injection (ICSI) due to male factor infertility. The FF was analyzed by two-dimensional gel electrophoresis (2-DE). The power of two-dimensional gel electrophoresis and the identification of proteins were exploited using matrix-assisted laser desorption-ionization time-of-flight/time-of-flight (MALDI-TOF-TOF) mass spectrometry. Twenty three protein spots showed reproducible and significant changes in the aged compared to the young group. Of these, 19 protein spots could be identified using MALDI-TOF-TOF-MS. As a result of MASCOT search, five unique downregulated proteins were identified in the older group. These were identified as serotransferrin, hemopexin precursor, complement C3, C4 and kininogen. A number of protein markers were found that may help develop diagnostic methods of infertility.

A proteomic analysis on human sperm tail: comparison between normozoospermia and asthenozoospermia

“…The isoelectric focusing The second dimension was carried out in 13.5 % separating gels using the Dodeca Cell System (Bio-Rad Laboratories, Hercules CA, USA) at a constant voltage and 50 mA per gel at 15°C for 7 h [21].…”

“…Analysis was carried out by the Proteomics Laboratory; University of York, U.K., using MALDI-TOF-TOF mass spectrometry as previously described [21].…”

“…The following specified parameters were applied for the database search: database (SwissProt), taxonomy (homo sapiens), proteolytic enzyme (trypsin), peptide mass tolerance (±100 ppm), fragment mass tolerance (±0.5 Da), fixed modification (carbamidomethyl (Cys)), variable modification (oxidation (Met)), and max missed cleavage [21].…”

Complement C3 and anti-testosterone antibody in the 150 kDa Bali cattle (Bos sondaicus/javanicus) subordinate follicular fluid peptide observed using MALDI-TOF/TOF-MS

“…The presence of Complement C3 has been reported in the human follicular fluid, and it was abundant in younger group as compared to older group (Hashemitabar et al, 2014). Complement C3 has also identified in the mare follicular fluid (Fahiminiya et al, 2010), in the buffalo (Fu et al, 2016); but is limited in the cows.…”

The Use of Proteomics in Assisted Reproduction

“…Finally, HFF comparative proteomic analysis (2-DE MALDI-TOF MS) of young and older women has identified five downregulated proteins in the older group (serotransferrin, hemopexin precursor, complement C3, C4 and kininogen), that may be considered of markers of reproductive aging and possibly infertility (94).…”