Exposure to Di-(2-Ethylhexyl) phthalate drives ovarian dysfunction by inducing granulosa cell pyroptosis via the SLC39A5/NF-κB/NLRP3 axis.

Endocrine-disrupting chemicals (EDCs) have been reported to affect populations by disrupting the human endocrine system. Di-(2-ethylhexyl) phthalate (DEHP) is an EDC that is present in various consumer products. Exposure to DEHP could contribute to reproductive system dysfunction, with subsequent adverse female reproductive outcomes. Granulosa cells (GCs) play essential roles in ovarian function and fertility. To further reveal the underlying mechanism by which DEHP impairs female fertility and affects the normal function of GCs, in vivo and in vitro experiments were performed. Transcript sequencing was used to identify genes that were differentially expressed in GCs after DEHP treatment. SLC39A5 was shown to be overexpressed in the DEHP group compared to the normal control group. DEHP treatment and overexpression of SLC39A5 activated NF-κB-related factors, followed by an increase in the transcript expression level of NLRP3. NLRP3 inflammasomes play crucial roles in pyroptosis by acting as sensors. Pyroptosis is a type of inflammation-related cell death associated with various diseases, including ovarian cancer and polycystic ovary syndrome. Activation of NF-κB contributed to the upregulation of pyroptosis in GCs, while pyroptosis factors were downregulated after the inhibition of NF-κB with JSH-23. The same phenomenon was also observed in a mouse model in which DEHP-treated mice had higher expression levels of NF-κB and pyroptosis markers in GCs. Moreover, this phenomenon could be partially reversed by the NF-κB inhibitor JSH-23. DEHP treatment also disrupted the normal expression of ovarian function-related genes and inhibited the proliferation of GCs. Reproductive system impairment was observed in mice exposed to DEHP. DEHP-treated mice had a lower body weight, smaller reproductive organs, fewer healthy follicles, and diminished ovarian reserve. Thus, DEHP contributes to ovarian dysfunction by inducing pyroptosis via the SLC39A5/NF-κB/NLRP3 axis in GCs.

Melatonin improves pregnancy outcomes in adenomyosis mice by restoring endometrial receptivity via NF-κB/apoptosis signaling.

Background: Adenomyosis is a common gynecological disease which seriously impacts female fertility and is increasing in incidence in women of childbearing age. Melatonin has beneficial effects on reproductive processes. However, its impact on the uterine receptivity of patients with adenomyosis remains unclear. In this study, we investigated the effect of melatonin on uterine receptivity and pregnancy outcomes in an adenomyosis mouse model. Methods: We induced an adenomyosis mouse model by oral administration of tamoxifen to neonatal female CD-1 mice, then conducted a melatonin injection experiment to investigate its effect on implantation rates (n=6 each). In a second experiment, the endometrium in the implantation state was collected to identify the local action of melatonin on adenomyosis mice (n=6 each), and in a parallel study, the pregnancy rate and number of offspring were recorded (n=6 each). Results: The number of implantation sites in the adenomyosis model mice was much less than in control group (5.0±2.10 vs. 13.3±2.38, P<0.0001), and 30 mg/kg of melatonin significantly improved this (9.0±0.63 vs. 5.0±2.10, P=0.002). Additionally, melatonin administration ameliorated the impaired endometrial receptivity [leukemia inhibitory factor (LIF), integrin ß3, homeobox A10 (HoxA10), and HoxA11], and improved the endometrium development [endometrial area (EA) and endometrial thickness index (ETI)] and pregnancy outcomes. Furthermore, the expression of implantation-related genes (Era, Pra, and P53), inflammatory factors [tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß)], oxidative stress associated genes (Gpx1 and Sod1), and apoptosis-related genes or proteins (Bax, Bcl-2, caspase-3, and cleaved caspase-3) was detected. The results showed higher local levels of reactive oxygen species (ROS) and inflammatory cytokines in the uterus of an adenomyosis model mice induced endometrial cells apoptosis and tissue damage, changed the uterine microenvironment, affected embryo implantation, and reduced the fertility of adenomyosis. Interestingly, melatonin significantly mitigated adenomyosis-induced changes by inhibiting the nuclear factor kappa B (NF-κB) signaling pathway, increasing the vascular endothelial growth factor (VEGF) expression, decreasing the endometrial cells apoptosis, and improving pregnancy outcomes. Conclusions: Melatonin treatment restored impaired uterine development and endometrial receptivity of adenomyosis mice by improving the endometrial microenvironment via the NF-κB/apoptosis signaling pathway. Our results provided new insight into melatonin-based therapy for adenomyosis-related infertility.