Assessment of the carcinogenic effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin using mouse embryonic stem cells to form teratoma in vivo

Perfluorinated iodine alkanes promote the differentiation of mouse embryonic stem cells by regulating estrogen receptor signaling

Investigating the development toxicity of perfluorinated iodine alkanes (PFIs) is critical, given their estrogenic effects through binding with estrogen receptors (ERs). In the present study, two PFIs, including dodecafluoro-1,6-diiodohexane (PFHxDI) and tridecafluorohexyl iodide (PFHxI), with binding preference to ERα and ERβ, respectively, were selected to evaluate their effects on proliferation and differentiation of the mouse embryonic stem cells (mESCs). The results revealed that, similar to E2, 50 µmol/L PFHxDI accelerated the cell proliferation of the mESCs. The PFI stimulation at the exposure concentrations of 2-50 µmol/L promoted the differentiation of the mESCs as characterized by the upregulation of differentiation-related biomarkers (i.e., Otx2 and Dnmt3β) and downregulation of pluripotency genes (i.e., Oct4, Nanog, Sox2, Prdm14 and Rex1). Comparatively, PFHxDI exhibited higher induction effect on the differentiation of the mESCs than did PFHxI. The tests on ER signaling indicated that both PFI compounds induced exposure concentration-dependent expressions of ER signaling-related biomarkers (i.e., ERα, ERβ and Caveolin-1) in the mESCs, and the downstream ER responsive genes (i.e., c-fos, c-myc and c-jun) well responded to PFHxI stimulation. The role of ER in PFI-induced effects on the mESCs was further validated by the antagonistic experiments using an ER inhibitor (ICI). The findings demonstrated that PFIs triggered ER signaling, and perturbed the differentiation program of the mESCs, causing the potential health risk during early stage of development.

Triazole fungicides exert neural differentiation alteration through H3K27me3 modifications: In vitro and in silico study

Considering that humans are unavoidably exposed to triazole fungicides through the esophagus, respiratory tract, and skin contact, revealing the developmental toxicity of triazole fungicides is vital for health risk assessment. This study aimed to screen and discriminate neural developmental disorder chemicals in commonly used triazole fungicides, and explore the underlying harmful impacts on neurogenesis associated with histone modification abnormality in mouse embryonic stem cells (mESCs). The triploblastic and neural differentiation models were constructed based on mESCs to expose six typical triazole fungicides (myclobutanil, tebuconazole, hexaconazole, propiconazole, difenoconazole, and flusilazole). The result demonstrated that although no cytotoxicity was observed, different triazole fungicides exhibited varying degrees of alterations in neural differentiation, including increased ectodermal differentiation, promoted neurogenesis, increased intracellular calcium ion levels, and disturbance of neurotransmitters. Molecular docking, cluster analysis, and multiple linear regressions demonstrated that the binding affinities between triazole fungicides and the Kdm6b-ligand binding domain were the dominant determinants of the neurodevelopmental response. This partially resulted in the reduced enrichment of H3K27me3 at the promoter region of the serotonin receptor 2 C gene, finally leading to disturbed neural differentiation. The data suggested potential adverse outcomes of triazole fungicides on embryonic neurogenesis even under sublethal doses through interfering histone modification, providing substantial evidence on the safety control of fungicides.

Research progress in seed cells for cartilage tissue engineering

Cartilage defects trouble millions of patients worldwide and their repair via conventional treatment is difficult. Excitingly, tissue engineering technology provides a promising strategy for efficient cartilage regeneration with structural regeneration and functional reconstruction. Seed cells, as biological prerequisites for cartilage regeneration, determine the quality of regenerated cartilage. The proliferation, differentiation and chondrogenesis of seed cells are greatly affected by their type, origin and generation. Thus, a systematic description of the characteristics of seed cells is necessary. This article reviews in detail the cellular characteristics, research progress, clinical translation challenges and future research directions of seed cells while providing guidelines for selecting appropriate seed cells for cartilage regeneration.

Graphene Quantum Dots Disrupt Embryonic Stem Cell Differentiation by Interfering with the Methylation Level of Sox2

The tremendous potential for graphene quantum dots (GQDs) in biomedical applications has led to growing concerns of their health risks in human beings. However, present studies mainly focused on oxidative stress, apoptosis, and other general toxicity effects; the knowledge on the developmental toxicity and the related regulatory mechanisms is still far from sufficient. Our study revealed the development retardation of mouse embryonic stem cells (mESCs) caused by GQDs with a novel DNA methylation epigenetic mechanism. Specifically, GQDs were internalized into cells mainly via energy-dependent endocytosis, and a significant fraction of internalized GQDs remained in the cells even after a 48-h clearance period. Albeit with unobservable cytotoxicity or any influences on cell pluripotency, significant retardation was found in the in vitro differentiation of the mESCs into embryoid bodies (EBs) with the upregulation of Sox2 levels in GQD pretreatment groups. Importantly, this effect could be contributed by GQD-induced inhibition in CpG methylation of Sox2 through altering methyltransferase and demethyltransferase transcriptional expressions, and the demethyltransferase inhibitor, bobcat339 hydrochloride, reduced GQD-induced upregulation of Sox2. The current study first demonstrated that GQDs compromised the differentiation program of the mESCs, potentially causing development retardation. Exposure to this nanomaterial during gestation or early developmental period would cause adverse health risks and is worthy of more attention.