Regulation of AKT Signaling in Mouse Uterus

Resveratrol inhibits white adipose deposition by the ESR1-mediated PI3K/AKT signaling pathway

Excessive adipose accumulation is the primary cause of obesity. Resveratrol (RES), a natural polyphenolic compound, has garnered significant attention for its anti-obesity properties. However, the precise mechanisms by which RES influences fat deposition have not yet been explored. In this study, the aim was to identify the target proteins and associated pathways of RES in order to elucidate the mechanisms by which RES reduces fat deposition. In this study, mice were administered 400 mg/kg of RES via gavage for 12 weeks. We found that while 400 mg/kg RES had no impact on the growth of the mice, it significantly reduced the weight of various white adipose tissues, as well as the serum and liver concentrations of total cholesterol and triglycerides. Network pharmacology identified 15 potential targets of RES and highlighted the PI3K/AKT signaling pathway as a key pathway. Molecular docking and dynamic simulations suggested that ESR1 might be the target protein through which RES exerts its anti-fat deposition effects. In vitro experiments revealed that ESR1 promotes the proliferation and inhibits the differentiation of 3 T3-L1 adipocytes, and suppresses the PI3K/AKT signaling pathway. Silencing the ESR1 gene altered the ability of RES to inhibit cell differentiation via the PI3K/AKT pathway. Gene expression results in subcutaneous adipose tissue, epididymal fat tissue, and liver tissue of mice were consistent with observations in cells. In summary, RES reduces white fat deposition by directly targeting the ESR1 protein and inhibiting the PI3K/AKT signaling pathway. Our findings provide new insights into the potential use of RES in the prevention and treatment of obesity.

Uterine-specific Ezh2 deletion enhances stromal cell senescence and impairs placentation, resulting in pregnancy loss

Maternal uterine remodeling facilitates embryo implantation, stromal cell decidualization and placentation, and perturbation of these processes may cause pregnancy loss. Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase that epigenetically represses gene transcription; loss of uterine EZH2 affects endometrial physiology and induces infertility. We utilized a uterine Ezh2 conditional knockout (cKO) mouse to determine EZH2's role in pregnancy progression. Despite normal fertilization and implantation, embryo resorption occurred mid-gestation in Ezh2cKO mice, accompanied by compromised decidualization and placentation. Western blot analysis revealed Ezh2-deficient stromal cells have reduced amounts of the histone methylation mark H3K27me3, causing upregulation of senescence markers p21 and p16 and indicating that enhanced stromal cell senescence likely impairs decidualization. Placentas from Ezh2cKO dams on gestation day (GD) 12 show architectural defects, including mislocalization of spongiotrophoblasts and reduced vascularization. In summary, uterine Ezh2 loss impairs decidualization, increases decidual senescence, and alters trophoblast differentiation, leading to pregnancy loss.

Oryzalin impairs maternal-fetal interaction during early pregnancy via ROS-mediated P38 MAPK/AKT and OXPHOS downregulation

Oryzalin is a dinitroaniline pesticide for the control of weed growth via suppression of microtubule synthesis. There are studies about the deleterious effects of dinitroaniline pesticides on the reproductive system. Therefore, we attempted to demonstrate the toxic mechanisms of oryzalin on early pregnancy using porcine uterine epithelial cells (pLE) and trophectoderm (pTr) cells. According to our results, the viability and proliferation of pLE and pTr cells were suppressed in response to oryzalin exposure, and cell cycle progression was affected. Additionally, oryzalin induced apoptotic cell death and impaired mitochondrial membrane polarity in pLE and pTr cells. Moreover, we confirmed that oryzalin significantly downregulated adenosine triphosphate (ATP) production via the oxidative phosphorylation system and upregulated reactive oxygen species (ROS) generation in both pLE and pTr cells. The oryzalin-induced ROS generation was mitigated by N-acetylcysteine, a ROS scavenger, and further upregulation of phosphor-P38 MAPK/AKT/P70S6K protein expression was ameliorated in both pLE and pTr cells. We also confirmed that the suppression of migration and proliferation in oryzalin-treated pLE and pTr cells was restored upon oxidative stress mitigation. In summary, we revealed that the cytotoxic mechanisms of oryzalin-induced implantation failure were mediated by ROS-induced intracellular signaling regulation and migratory potential in pLE and pTr cells.

Estradiol and Estrogen-like Alternative Therapies in Use: The Importance of the Selective and Non-Classical Actions

Estrogen is one of the most important female sex hormones, and is indispensable for reproduction. However, its role is much wider. Among others, due to its neuroprotective effects, estrogen protects the brain against dementia and complications of traumatic injury. Previously, it was used mainly as a therapeutic option for influencing the menstrual cycle and treating menopausal symptoms. Unfortunately, hormone replacement therapy might be associated with detrimental side effects, such as increased risk of stroke and breast cancer, raising concerns about its safety. Thus, tissue-selective and non-classical estrogen analogues have become the focus of interest. Here, we review the current knowledge about estrogen effects in a broader sense, and the possibility of using selective estrogen-receptor modulators (SERMs), selective estrogen-receptor downregulators (SERDs), phytoestrogens, and activators of non-genomic estrogen-like signaling (ANGELS) molecules as treatment.

EZH2 and Endometrial Cancer Development: Insights from a Mouse Model

Enhancer of zeste homolog 2 (EZH2), a core component of polycomb repressive complex 2, plays an important role in cancer development. As both oncogenic and tumor suppressive functions of EZH2 have been documented in the literature, the objective of this study is to determine the impact of Ezh2 deletion on the development and progression of endometrial cancer induced by inactivation of phosphatase and tensin homolog (PTEN), a tumor suppressor gene frequently dysregulated in endometrial cancer patients. To this end, we created mice harboring uterine deletion of both Ezh2 and Pten using Cre recombinase driven by the progesterone receptor (Pgr) promoter. Our results showed reduced tumor burden in Pten^d/d; Ezh2^d/d mice compared with that of Pten^d/d mice during early carcinogenesis. The decreased Ki67 index in EZH2 and PTEN-depleted uteri versus that in PTEN-depleted uteri indicated an oncogenic role of EZH2 during early tumor development. However, mice harboring uterine deletion of both Ezh2 and Pten developed unfavorable disease outcome, accompanied by exacerbated epithelial stratification and heightened inflammatory response. The observed effect was non-cell autonomous and mediated by altered immune response evidenced by massive accumulation of intraluminal neutrophils, a hallmark of endometrial carcinoma in Pten^d/d; Ezh2^d/d mice during disease progression. Hence, these results reveal dual roles of EZH2 in endometrial cancer development.