Do follicular fluid advanced glycation end products levels affect the ovarian response in unexplained infertility?

Advanced Glycation End-Products of Follicular Fluid are Associated with Embryo Morphokinetic Parameters and ART Outcomes

Advanced glycation end products (AGEs) can disrupt antioxidant system and steroidogenesis, resulting in detrimental effects on assisted reproductive technology (ART) outcomes. This study aimed to investigate the association of AGEs in follicular fluid (FF) with morphokinetic parameters of embryos and ART outcomes. Fifty women undergoing ART treatment were studied. AGEs, glucose, 25(OH) vitamin D, malondialdehyde (MDA) levels and catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) activities were evaluated in FF. The expression of 3βHSD, CYP11A1, and CYP19A1 genes were analyzed in granulosa cells (GCs) by qRT-PCR technique. Morphokinetic parameters were evaluated using time-lapse technology. The FF level of AGEs was reversely associated with CAT, SOD, and GPX activities, and total and mature oocytes number, blastocyst formation rate, and high-grade embryos number, while it showed positive correlations with the FF MDA levels, the expression of steroidogenesis genes, number of immature oocytes, morphokinetic parameters, and number of low-grade embryos. Furthermore, the level of vitamin D in FF had an inverse association with AGEs and positive correlations with ART outcomes and morphokinetic parameters. Comparison between the those with positive and negative biochemical pregnancy showed no significant differences in terms of FF factors and just the expression of 3βHSD, CYP11A1, and CYP19A1 genes were higher in pregnant women (p < 0.05). AGEs could delay blastomere division and lead to an increase in the number of low-quality embryos, while vitamin D have an adverse effect on AGEs and a protective function against AGEs negative effects.

Follicular fluid advanced glycation end products in assisted reproduction: A systematic review

Follicular fluid (FF) advanced glycation end products (AGEs) have been associated with low oocyte quality and number, low fertilization rate, impaired embryonic development and low pregnancy rate. These findings are especially relevant in women undergoing in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), ie, assisted reproductive technology (ART). A systematic literature search was conducted to examine various AGEs including pentosidine, carboxymethyl-lysine (CML), methylglyoxal 5-hydro-5-methylimidazolones (MG-H1), toxic AGE (TAGE), and soluble receptor for AGE (sRAGE) with ART outcomes. Studies showed that total AGEs and sRAGE in FF were associated with the ovarian response, follicle number, retrieved oocyte number, mature (MII) oocyte number, fertilization rate, embryo number, embryo quality, and successful pregnancy. Although FF AGEs could be considered predictive biomarkers, population heterogeneity and differences in ovulation induction protocols make the findings less clear. This review highlights important role of AGEs in ART and necessity of evaluating AGEs in serum vs with FF to better predict ART outcomes.

Advanced Glycation End-Products (AGEs): Formation, Chemistry, Classification, Receptors, and Diseases Related to AGEs

Advanced glycation end-products (AGEs) constitute a non-homogenous, chemically diverse group of compounds formed either exogeneously or endogeneously on the course of various pathways in the human body. In general, they are formed non-enzymatically by condensation between carbonyl groups of reducing sugars and free amine groups of nucleic acids, proteins, or lipids, followed by further rearrangements yielding stable, irreversible end-products. In the last decades, AGEs have aroused the interest of the scientific community due to the increasing evidence of their involvement in many pathophysiological processes and diseases, such as diabetes, cancer, cardiovascular, neurodegenerative diseases, and even infection with the SARS-CoV-2 virus. They are recognized by several cellular receptors and trigger many signaling pathways related to inflammation and oxidative stress. Despite many experimental research outcomes published recently, the complexity of their engagement in human physiology and pathophysiological states requires further elucidation. This review focuses on the receptors of AGEs, especially on the structural aspects of receptor-ligand interaction, and the diseases in which AGEs are involved. It also aims to present AGE classification in subgroups and to describe the basic processes leading to both exogeneous and endogeneous AGE formation.