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The developmental toxicity and human health risks of triazole fungicides (TFs) have attracted worldwide attention due to the ability to enter the human body in a variety of ways. Nevertheless, the specific mechanism by which TFs exert remains incompletely understood. Given that retinoic acid (RA) signaling pathway are closely related to development, this study aimed to screen and identify developmentally disabled chemicals in commonly used TFs and to reveal the potential effects of TFs on developmental retardation through the RA signaling pathway in mouse embryonic stem cells (mESCs). Specifically, six typical TFs (myclobutanil, tebuconazole, hexaconazole, propiconazole, difenoconazole, and flusilazole) were exposed through the construction of an embryoid bodies (EBs)-based in vitro global differentiation models. Our results clarified that various TFs disturbed lineage commitment during early embryonic development. Crucially, the activation of RA signaling pathway, which alters the expression of key genes and interferes the transport and metabolism of retinol, may be responsible for this effect. Furthermore, molecular docking, molecular dynamics simulations, and experiments using a retinoic acid receptor α inhibitor provide evidence supporting the potential modulatory role of the retinoic acid signaling pathway in developmental injury. The current study offers new insights into the TFs involved in the RA signaling pathway that interfere with the differentiation process of mESCs, which is crucial for understanding the impact of TFs on pregnancy and early development., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the expression of key genes and proteins of retinoic acid signaling pathway in procymidone-induced uterine injury in adolescent mice, and analyze the relationship between the signaling pathway and female reproductive damage., Methods: The 3-week age ICR mice were randomly divided into low, medium, and high-dose groups and one control group with 8 mice in each group by weight. The low, medium and high dose groups were respectively given 50, 100 and 200 mg/(kg·d) procymidone orally for 21 days continuously, while the control group was given equal volume of soybean oil. After the mice were sacrificed, the uterus was taken from both sides for observing the histological changes in the cross-sectional slices of the uterus, the detection of the expression abundance of genes which related to the retinoic acid signaling pathway by the real-time fluorescent quantitative PCR, and the measurement of ALDH2 and CYP26 a1 proteins expression by Western blot., Results: The body weight of mice in low-dose, medium-dose and high-dose groups were(27.50±1.49) g, (27.72±1.40) g and(26.89±1.19) g, respectively, which were lower than those in control group(31.48±1.14) g(P<0.05). The density of uterine lining monolayer columnar epithelium and lamina propria tubular uterine glands gradually decreases, at the same time the uterine folds become less with the dose of procymidone increases. adh1, ad/2, aldh1a1 in each experimental group were higher than those in the control group(P<0.05); the expression levels of aldh1a2 and aldh1a3 genes in the middle and high dose groups were higher than those in the control group(P<0.05); the expression levels of retinoic acid nuclear receptor rarα, rarγ, rxrα and rxrβ genes in the high-dose group were higher than those in the control(P<0.05); yet the expression levels of cyp26a2 and cyp26a3 in the high-dose group were lower than those in the control group(P<0.05); the jnk family in medium and high dose groups were higher than the control(P<0.05). The expression of ALDH2 in each experimental group was higher than that in the control group, and increased with the increase of the dose(P<0.05); the expression of CYP26 a1 in each experimental group was not significantly different from that of the control group., Conclusion: The retinoic acid signal pathway is activated in procymidone-induced uterine injury in mice, then regulates the increase of the expression of jnk family, leading to the damage.

Background: In the classical pathway of retinoic acid (RA) mediated gene transcription, RA binds to a nuclear hormone receptor dimer composed of retinoic acid receptor (RAR) and retinoid X receptor (RXR), to induce the expression of its downstream target genes. In addition to nuclear receptors, there are other intracellular RA binding proteins such as cellular retinoic acid binding proteins (CRABP1 and CRABP2) and cytochrome P450 (CYP) enzymes, whose contributions to the RA signaling pathway have not been fully understood. The objective of this study was to compare the significance of various RA binding receptors, i.e. CRABP1, CRABP2, CYP and RAR in the RA signaling pathway. In this regard, we developed a mathematical model of the RA pathway, which is one of the few models, if not the only one, that includes all main intracellular RA binding receptors. We then performed a global sensitivity analysis (GSA) to investigate the contribution of the RA receptors to RA-induced mRNA production, when the cells were treated with a wide range of RA levels, from physiological to pharmacological concentrations., Results: Our results show that CRABP2 and RAR are the most and the least important proteins, respectively, in controlling the model performance at physiological concentrations of RA (1-10 nM). However, at higher concentrations of RA, CYP and RAR are the most sensitive parameters of the system. Furthermore, we found that depending on the concentrations of all RA binding proteins, the rate of metabolism of RA can either change or remain constant following RA therapy. The cellular levels of CRABP1 are more important than that of CRABP2 in controlling RA metabolite formation at pharmacological conditions (RA = 0.1-1 μM). Finally, our results indicate a significant negative correlation between total mRNA production and total RA metabolite formation at pharmacological levels of RA., Conclusions: Our simulations indicate that the significance of the RA binding proteins in the RA pathway of gene expression strongly depends on intracellular concentration of RA. This study not only can explain why various cell types respond to RA therapy differently, but also can potentially help develop pharmacological methods to increase the efficacy of the drug.