Ascorbic acid improves pluripotency of human parthenogenetic embryonic stem cells through modifying imprinted gene expression in the Dlk1-Dio3 region

Ascorbic Acid 2-Glucoside Stably Promotes the Primitiveness of Embryonic and Mesenchymal Stem Cells Through Ten-Eleven Translocation- and cAMP-Responsive Element-Binding Protein-1-Dependent Mechanisms

Aims: The naive or primitive states of stem cells (SCs) residing in specific niches are unstable and difficult to preserve in vitro. Vitamin C (VitC), in addition to suppressing oxygen radicals, exerts pleiotropic effects to preserve the core functions of SCs. However, this compound is labile and readily oxidized, resulting in cellular toxicity and preventing its reliable application in this context. We found that a VitC derivative, ascorbic acid 2-glucoside (AA2G), stably maintains the naive pluripotency of murine embryonic SCs (mESCs) and the primitiveness of human mesenchymal SCs (hMSCs) without cellular toxicity. Results: The beneficial effects of AA2G and related molecular mechanisms were evaluated in mESCs, induced pluripotent-SCs (iPSCs), and hMSCs. AA2G was stable in aqueous solution and barely induced cellular toxicity in cultured SCs, unlike VitC. AA2G supplementation recapitulated the well-known effects of VitC, including induction of ten-eleven translocation-dependent DNA demethylation in mESCs and suppression of p53 during generation of murine iPSCs. Furthermore, supplementation of hMSCs with AA2G improved therapeutic outcomes in an asthma mouse model by promoting their self-renewal, engraftment, and anti-inflammatory properties. Particularly, activation of the cAMP-responsive element-binding protein-1 (CREB1) pathway contributed to the ability of AA2G to maintain naive pluripotency of mESCs and functionality of hMSCs. Innovation and Conclusion: Given its long-lasting effects and low cellular toxicity, AA2G supplementation is useful to support the naive pluripotency of mESCs and the primitiveness of hMSCs, affecting their developmental potency and therapeutic efficacy. Furthermore, we demonstrate the significance of the CREB1 pathway in the mechanism of action of AA2G.

Oocyte collection and in vitro maturation after train transportation of human follicular fluid aspirated from resected non-stimulated ovaries of patients with endometrial adenocarcinoma

PURPOSE

Immature human oocytes from resected ovaries can be used for research and fertility preservation, though it is unknown whether it is feasible to transport oocytes for these purposes. This study examined in vitro maturation (IVM) outcomes after the transportation of human follicular fluid (HFF) containing oocytes.

METHODS

Fourteen patients with endometrial adenocarcinoma were enrolled. Oocytes obtained from the resected ovaries of seven patients were transported with HFF by railway (transportation group). Samples of HFF from the other seven patients were not transported, and IVM was performed promptly (non-transportation group). The results of oocyte retrieval and IVM were compared.

RESULTS

The average ages in the transportation and non-transportation groups were 40.1 ± 2.0 and 39.6 ± 1.8 years, respectively, and the average numbers of collected oocytes were 8.1 ± 8.4 and 5.1 ± 5.1, respectively. There was a significant negative correlation between the number of collected oocytes and age. The proportions of oocytes that reached meiosis II (maturation rate) after IVM were 38.6% and 69.2% in the transportation and non-transportation groups, respectively (P = 0.013).

CONCLUSION

In this preliminary study, the usefulness of the transportation of HFF was limited. Further studies on maintaining oocyte normality during transportation are necessary for becoming the effective method for research and clinical use.

The Type 3 Deiodinase: Epigenetic Control of Brain Thyroid Hormone Action and Neurological Function

Thyroid hormones (THs) influence multiple processes in the developing and adult central nervous system, and their local availability needs to be maintained at levels that are tailored to the requirements of their biological targets. The local complement of TH transporters, deiodinase enzymes, and receptors is critical to ensure specific levels of TH action in neural cells. The type 3 iodothyronine deiodinase (DIO3) inactivates THs and is highly present in the developing and adult brain, where it limits their availability and action. DIO3 deficiency in mice results in a host of neurodevelopmental and behavioral abnormalities, demonstrating the deleterious effects of TH excess, and revealing the critical role of DIO3 in the regulation of TH action in the brain. The fact the Dio3 is an imprinted gene and that its allelic expression pattern varies across brain regions and during development introduces an additional level of control to deliver specific levels of hormone action in the central nervous system (CNS). The sensitive epigenetic nature of the mechanisms controlling the genomic imprinting of Dio3 renders brain TH action particularly susceptible to disruption due to exogenous treatments and environmental exposures, with potential implications for the etiology of human neurodevelopmental disorders.

Valproic Acid Induces Decreased Expression of H19 Promoting Cell Apoptosis in A549 Cells

It has been suggested that the imprinted gene, H19, plays a crucial role in the development of cancer. In the present study, we attempted to treat the abnormal expression and methylation status of H19 in A549 cells using valproic acid (VPA), ascorbic acid (Vc), and 5-aza-Cytidine (5-Aza). The results suggested that VPA administration could alter the expression pattern of H19, while the hypomethylation status of H19 DMR was unchanged. Furthermore, overexpression of HDAC1 and DNMT1 was associated with decreased expression of H19 in VPA-treated cells. Western blot results showed that the expression of p53 protein was increased following treatment with VPA. In addition, we also investigated cellular apoptosis and the cell cycle of treated cells. Flow cytometry data indicated that VPA could increase the occurrence of cell apoptosis in A549 cells. Taken together, our results suggest that H19 expression was suppressed by VPA through HDAC1 and DNMT1 and decreased H19 expression correlated with cell apoptosis in A549 cells.