A Proteomic Analysis of Human Follicular Fluid: Proteomic Profile Associated with Embryo Quality.

Embryo selection is a key point of in vitro fertilization (IVF). The most commonly used method for embryo selection is morphological assessment. However, it is sometimes inaccurate. Follicular fluid (FF) contains a complex mixture of proteins that are essential for follicle development and oocyte maturation. Analyzing human FF proteomic profiles and identifying predictive biomarkers might be helpful for evaluating embryo quality. A total of 22 human FF samples were collected from 19 infertile women who underwent IVF/intracytoplasmic sperm injection (ICSI) treatment between October 2021 and November 2021. FFs were grouped into two categories on the basis of the day 3 embryo quality, grade I or II in the hqFF group and grade III in the nhqFF group. FF was analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). The key differentially expressed proteins (DEPs) were validated by parallel reaction monitoring (PRM) and enzyme-linked immunosorbent assay (ELISA). Differentially expressed proteins were further analyzed using DAVID software. A total of 558 proteins were identified, of which 50 proteins were differentially expressed in the hqFF versus nhqFF group, including 32 upregulated proteins (> 1.20-fold, P < 0.05) and 18 downregulated proteins (< 0.67-fold, P < 0.05). Bioinformatics analyses showed that the upregulated DEPs were enriched in components of the coagulation and complement systems and negative regulation of peptidase activity, while the downregulated DEPs were enriched in molecular function of extracellular matrix structural and constituent collagen binding. Our results suggested that a number of protein biomarkers in FF were associated with embryo quality. It may help develop an effective and noninvasive method for embryo selection.

Association of sexually transmitted infection with semen quality in men from couples with primary and secondary infertility.

This study aims to compare the prevalence of sexually transmitted infections (STIs) with semen quality in men from couples with primary and secondary infertility. Semen samples were collected from 133 men who requested fertility evaluation. Seminal tract infection with Ureaplasma spp. (UU), Mycoplasma hominis (MH), Mycoplasma genitalium (MG), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and herpes simplex virus-2 (HSV-2) was assessed by PCR-based diagnostic assays. Among all patients, the prevalence of STIs was higher in men from couples with primary infertility than that in men from couples with secondary infertility (39.7% vs 21.7%, P = 0.03). The prevalence of UU was 28.8% and 13.3% in men from couples with primary and secondary infertility, respectively. Men from couples with primary infertility were more likely to be positive for UU than men from couples with secondary infertility (P = 0.04). Regarding the UU subtype, the prevalence of Ureaplasma urealyticum (Uuu) and Ureaplasma parvum (Uup; including Uup1, Uup3, Uup6, and Uup14) did not differ between the two groups. No associations between the prevalence rates of MH, MG, and CT were found in men from either infertility group. A lower sperm concentration was associated with STI pathogen positivity in men with primary infertility according to the crude model (P = 0.04). The crude and adjusted models showed that semen volume (both P = 0.03) and semen leukocyte count (both P = 0.02) were independently associated with secondary infertility. These findings suggest the importance of classifying the type of infertility during routine diagnosis of seminal tract infections.

NLRC5 Inhibits Inflammation of Secretory Phase Ectopic Endometrial Stromal Cells by Up-Regulating Autophagy in Ovarian Endometriosis.

Nod-like receptor (NLR) family caspase activation and recruitment domain containing 5 (NLRC5) is a newly identified sub-class of the NLR family. It regulates inflammation and has a key function in innate and adaptive immunologic reactions. Autophagy has been reported to be crucially linked to the pathogenesis of endometriosis. Our recent study identify there is a negative correlation between NLRC5 and autophagy in endometriosis, indicating that NLRC5 and autophagy together act as promising predictors in endometriosis patients. However, the mechanism associating NLRC5 and autophagy in endometriosis is still not completely understood. We hypothesize that autophagy could be involved in NLRC5-mediated inflammation in endometriosis. In order to validate the assumption, we evaluate the effects of NLRC5 and autophagy in the inflammation of ectopic endometrial stromal cells (EESCs) of ovarian endometriosis patients, to specifically determine whether autophagy is involved in NLRC5-mediated inflammation in EESCs. Our results show that over-expression of NLRC5 results in the up-regulation of autophagy in EESCs and inhibition of NLRC5 restricts the level of autophagy in EESCs. Furthermore, over-expression of NLRC5 and promotion of autophagy inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expressions, whereas inhibition of NLRC5 and autophagy up-regulate IL-6 and TNF-α expressions in EESCs. Additionally, promotion of autophagy contributes to the NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs; inhibition of autophagy restricts NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs. Our results suggest that over-expression of NLRC5 promotes autophagy, thereby inhibiting inflammation in ovarian endometriosis.

Aminopeptidase N expression in the endometrium could affect endometrial receptivity.

Aminopeptidase N (ANPEP) is a membrane-bound zinc-dependent peptidase. Although it is widely believed that ANPEP acts as an important angiogenesis regulatory factor, there are few studies about its function in the female reproductive system. In our previous research, we applied Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) to analyze the influence of different controlled superovulation treatments for Assisted Reproductive Technology, In Vitro Fertilization and Embryo Transfer (IVF-ET)) patients from a global proteomic perspective to search for potential biomarkers associated with endometrium receptivity and embryo implantation. ANPEP is one of the proteins that demonstrated differential expression between different treatment groups and may be closely associated with endometrial receptivity. In this study, we assessed the expression of ANPEP in the endometrium of mice at different ages and found it to be highest in the mature period. We also detected ANPEP expression in the endometrium of IVF-ET patients in the proliferative, preimplantation and implantation stages, and the highest expression level of ANPEP was found in the last group. Human primary endometrial stromal cells were infected with an adenovirus expression vector containing the ANPEP gene and a green fluorescent protein (GFP) fusion protein; the mRNA levels of HOXA-10, LIF, and integrin ß3 were found to be increased. Therefore, we conclude that ANPEP could be involved in the regulation of endometrial receptivity.