High seminal BPA in IVF patients correlates with lower sperm count and up-regulated miR-21 and miR-130a.

Bisphenol A (BPA) is a widespread industrial chemical, used as the key monomer of polycarbonate plastics and epoxy resins. BPA has been detected in human seminal fluid and has been correlated with changes in sperm parameters, crucial in determining male fertility. In this study, semen samples were collected from 100 patients aged 29-47 years undergoing fertility assessment between 2021 and 2023 and analyzed according to WHO guidelines. BPA levels in the seminal plasma were then measured through an enzyme-linked immunosorbent assay (ELISA) and compared to sperm quality metrics. The relative mRNA/miRNA expression of key genes associated to male reproduction, including androgen receptor, miR-34c, miR-21, miR-130a, was then quantified and compared between groups with high or low BPA content. Our results revealed that BPA levels were increased with age and were negatively correlated with sperm counts (p<0.05). The negative correlation remained significant when patients were age-matched. No other relationships between seminal BPA and motility, morphology or DNA fragmentation levels were observed. qPCR analysis showed that androgen receptor mRNA expression was significantly greater in sperm with high seminal BPA (p<0.05). Moreover, we found that the expression of miR-21 and miR-130a was also upregulated in the higher BPA group (p<0.05). These results display a relationship between BPA content in the semen and male fertility parameters, and provide insights into the molecular mechanisms through which BPA may be affecting male reproductive capability. Ultimately, this research can potentially drive changes to guidelines and exposure limits for BPA exposure.

THC and sperm: Impact on fertilization capability, pre-implantation in vitro development and epigenetic modifications.

Global cannabis use has risen 23% since 2010, with 209 million reported users, most of whom are males of reproductive age. Delta-9-tetrahydrocannabinol (THC), the main psychoactive phytocannabinoid in cannabis, disrupts pro-homeostatic functions of the endocannabinoid system (ECS) within the male reproductive system. The ECS is highly involved in regulating morpho-functional and intrinsic sperm features that are required for fertilization and pre-implantation embryo development. Previous work by our group demonstrated that THC altered sperm capacitation and the transcriptome, including several fertility-associated microRNAs (miRs). Despite the prevalent use of cannabis among males of reproductive age, clinical and pre-clinical research investigating the impact of paternal cannabis on sperm function and the outcomes of artificial reproductive technologies (ARTs) remains inconclusive. Therefore, the present study investigates the impact of in vitro THC exposure on morpho-functional and intrinsic sperm functions, including contributions to embryo development following IVF. Bovine sperm were used as a translational model for human and treated with concentrations of THC that reflect plasma levels after therapeutic (0.032µM), and low (0.32µM)-high (4.8µM) recreational cannabis use. After 6-hours of treatment, THC did not alter the acrosomal reaction, but 4.8µM significantly reduced mitochondrial membrane potential (MMP) (p<0.05), primarily through agonistic interactions with CB-receptors. Fertilization of bovine oocytes with THC-treated sperm did not alter developmental rates, but blastocysts generated from sperm treated with 0.32-4.8µM THC had fewer trophoblasts (p<0.05), while blastocysts generated from sperm exposed to any concentration of THC had fewer cells in the inner cell mass (ICM), particularly within the 0.032µM group (p<0.001). Fertility associated miRs, including miR-346, miR-324, miR-33b, and miR-34c were analyzed in THC-exposed sperm and associated blastocysts generated by IVF, with lower levels of miRs-346, -324, and -33b found in sperm treated with 0.32µM THC, while miR-34c levels were higher in sperm treated with 0.032µM THC (p<0.05). Levels of miR-346 were also lower in sperm treated with 0.032µM THC, but higher in blastocysts generated from sperm exposed to 0.32µM THC (p<0.05). Our findings suggest that THC may alter key morpho-functional and epigenetic sperm factors involved in fertilization and embryo development. This is the first study to demonstrate that sperm exposed to THC in vitro negatively affects embryo quality following IVF.

Potential Costs and Benefits of Incorporating PGT-A Across Age Groups: A Canadian Clinic Perspective.

OBJECTIVE: To assess the potential costs and benefits of preimplantation genetic testing for aneuploidy (PGT-A) across age groups, considering financial costs, total euploidy rates and the potential for morphology grading to predict a euploid embryo. METHODS: This study is a blinded retrospective chart review of patients who incorporated PGT-A as part of their in vitro fertilization (IVF) treatment cycle at a university-affiliated fertility clinic. Patients between 25-44 years of age undergoing IVF with intracytoplasmic sperm injection and PGT-A with autologous oocytes (n = 220) were included in this study. Number of blastocysts achieved, euploidy rates and PGT-A costs were compared between 3 age groups: <35 years, 35-37, and ≥38. Additionally, agreement on the top-quality embryo based on morphology assessment alone versus PGT-A selection was analyzed and further compared based on the number of blastocysts achieved. RESULTS: A significant negative correlation between patient age and number of embryos produced, PGT-A costs, and euploidy rates (P < 0.001) was observed. Additionally, morphology alone ratings were able to predict the top-quality euploid embryo 78% of the time in the <35 age group, but only 32% of the time in the ≥38 age group (P < 0.05), with a trend toward even lower agreement when 3 or fewer blastocysts were produced. CONCLUSION: Based on our cost analysis, it may be advantageous to incorporate PGT-A when maternal age is ≥38, given the lower financial costs associated with each cycle and the low likelihood of transferring a euploid embryo on the first attempt for this age group. Nevertheless, we acknowledge that PGT-A remains a complex decision influenced by a multitude of factors.

Genetic and Epigenetic Profiles of Polycystic Ovarian Syndrome and In Vitro Bisphenol Exposure in a Human Granulosa Cell Model.

Higher levels of bisphenols are found in granulosa cells of women with polycystic ovary syndrome (PCOS), posing the question: Is bisphenol exposure linked to PCOS pathophysiology? Human granulosa cells were obtained from women with and without PCOS, and genes and microRNAs associated with PCOS were investigated. The first phase compared healthy women and those with PCOS, revealing distinct patterns: PCOS subjects had lower 11ß-HSD1 (p = 0.0217) and CYP11A1 (p = 0.0114) levels and elevated miR-21 expression (p = 0.02535), elucidating the molecular landscape of PCOS, and emphasizing key players in its pathogenesis. The second phase focused on healthy women, examining the impact of bisphenols (BPA, BPS, BPF) on the same genes. Results revealed alterations in gene expression profiles, with BPS exposure increasing 11ß-HSD1 (p = 0.02821) and miR-21 (p = 0.01515) expression, with the latest mirroring patterns in women with PCOS. BPA exposure led to elevated androgen receptor (AR) expression (p = 0.0298), while BPF exposure was associated with higher levels of miR-155. Of particular interest was the parallel epigenetic expression profile between BPS and PCOS, suggesting a potential link. These results contribute valuable insights into the nuanced impact of bisphenol exposure on granulosa cell genes, allowing the study to speculate potential shared mechanisms with the pathophysiology of PCOS.

Quality of fresh and cryopreserved bovine sperm is reduced by BPA and BPF exposure.

Bisphenol A (BPA) is an endocrine disrupting compound, used as the key monomer of polycarbonate plastics and epoxy resins. BPA has been detected in both humans and farm animals and has been correlated with decreased sperm counts and motility. BPS and BPF are structural analogs of BPA and are increasingly being used in manufacturing as BPA substitutes. In this study we aim to assess the direct outcomes of BPA, BPS and BPF exposure on bovine sperm parameters in vitro to elucidate how they affect sperm quality and fertilization potential, and to assess whether BPS and/or BPF are less harmful than BPA. Sperm from three or more bulls was obtained from either fresh samples or cryopreserved straws and exposed to 0.05 mg/mL of BPA, BPS and BPF in vitro. After 4h incubation, motility, capacitation, apoptosis/necrosis, and mitochondrial membrane potential levels were measured by CASA or computational flow cytometry. Results showed that BPA exposure significantly reduced both fresh and cryopreserved sperm motility, capacitation, viability and mitochondrial membrane potential levels. Furthermore, BPF significantly decreased motility, capacitation and mitochondrial membrane potential in cryopreserved sperm only. BPS did not have any significant effects on any of the parameters measured. Our results suggest that BPA is the most harmful to sperm, while BPF is toxic under certain conditions, and BPS seems to be the least detrimental. Overall, this study provides an understanding of how the ubiquitous environmental chemicals, bisphenols, may impact male fertility even after ejaculation.

Sperm capacitation and transcripts levels are altered by in vitro THC exposure.

BACKGROUND: Delta-9-tetrahydrocannabinol (THC) is the primary phytocannabinoid responsible for the psychoactive properties of cannabis and is known to interact with the endocannabinoid system, which is functionally present in the male reproductive system. Since cannabis consumption is the highest among reproductive aged males, the current study aimed to further investigate the effects of THC exposure to phenotypical, physiological, and molecular parameters in sperm. Bull sperm of known fertility were used as a translational model for human sperm and subjected to in vitro treatment with physiologically relevant experimental doses of THC. Sperm parameters, capacitation, apoptosis, and transcript levels were evaluated following treatment. RESULTS: Motility, morphology, and viability of bovine sperm was unaltered from THC exposure. However, 0.32µM of THC caused an increased proportion of capacitating sperm (p < 0.05) compared to control and vehicle group sperm. Transcriptome analysis revealed that 39 genes were found to be differentially expressed by 0.032µM THC exposure, 196 genes were differentially expressed by 0.32µM THC exposure, and 33 genes were differentially expressed by 3.2µM THC. Secondary analysis reveals pathways involving development, nucleosomes, ribosomes and translation, and cellular metabolism to be significantly enriched. CONCLUSION: Phytocannabinoid exposure to sperm may adversely affect sperm function by stimulating premature capacitation. These findings also show for the first time that spermatozoal transcripts may be altered by THC exposure. These results add to previous research demonstrating the molecular effects of cannabinoids on sperm and warrant further research into the effects of cannabis on male fertility.

Effects of BPA, BPS, and BPF on Oxidative Stress and Antioxidant Enzyme Expression in Bovine Oocytes and Spermatozoa.

Bisphenol A (BPA) and its analogs, bisphenol S (BPS) and bisphenol F (BPF), might impact fertility by altering oxidative stress pathways. Here, we hypothesize that bisphenols-induced oxidative stress is responsible for decreased gamete quality. In both female (cumulus-oocyte-complexes-COCs) and male (spermatozoa), oxidative stress was measured by CM-H2DCFDA assay and key ROS scavengers (SOD1, SOD2, GPX1, GPX4, CAT) were quantified at the mRNA and protein levels using qPCR and Western blot (COCs)/immunofluorescence (sperm). Either gamete was treated in five groups: control, vehicle, and 0.05 mg/mL of BPA, BPS, or BPF. Our results show elevated ROS in BPA-treated COCs but decreased production in BPS- and BPF-treated spermatozoa. Additionally, both mRNA and protein expression of SOD2, GPX1, and GPX4 were decreased in BPA-treated COCs (p < 0.05). In sperm, motility (p < 0.03), but not morphology, was significantly altered by bisphenols. SOD1 mRNA expression was significantly increased, while GPX4 was significantly reduced. These results support BPA's ability to alter oxidative stress in oocytes and, to a lesser extent, in sperm. However, BPS and BPF likely act through different mechanisms.