The Role of 5-aza-2'-Deoxycytidine on Methylation Status of Xist Gene in Different Genders of Buffalo (Bubalus bubalis) Bone Marrow Mesenchymal Stem Cells

Histone Demethylase KDM4D Could Improve the Developmental Competence of Buffalo (Bubalus Bubalis) Somatic Cell Nuclear Transfer (SCNT) Embryos

Somatic cell nuclear transfer (SCNT) holds vast potential in agriculture. However, its applications are still limited by its low efficiency. Histone 3 lysine 9 trimethylation (H3K9me3) was identified as an epigenetic barrier for this. Histone demethylase KDM4D could regulate the level of H3K9me3. However, its effects on buffalo SCNT embryos are still unclear. Thus, we performed this study to explore the effects and underlying mechanism of KDM4D on buffalo SCNT embryos. The results revealed that compared with the IVF embryos, the expression level of KDM4D in SCNT embryos was significantly lower at 8- and 16-cell stage, while the level of H3K9me3 in SCNT embryos was significantly higher at 2-cell, 8-cell, and blastocyst stage. Microinjection of KDM4D mRNA could promote the developmental ability of buffalo SCNT embryos. Furthermore, the expression level of ZGA-related genes such as ZSCAN5B, SNAI1, eIF-3a, and TRC at the 8-cell stage was significantly increased. Meanwhile, the pluripotency-related genes like POU5F1, SOX2, and NANOG were also significantly promoted at the blastocyst stage. The results were reversed after KDM4D was inhibited. Altogether, these results revealed that KDM4D could correct the H3K9me3 level, increase the expression level of ZGA and pluripotency-related genes, and finally, promote the developmental competence of buffalo SCNT embryos.

Hypoxia Enhances Mesenchymal Characteristics Maintenance of Buffalo Bone Marrow-Derived Mesenchymal Stem Cells

Bone marrow-derived mesenchymal stem cells (BMSCs) from livestock are valuable resources for veterinary therapeutics and animal reproduction. Previous studies have shown that hypoxic conditions were beneficial in maintaining the mesenchymal feature of BMSCs. However, the effects of hypoxia on buffalo BMSCs (bBMSCs) remain unclear. In this study, the effects of hypoxic conditions on cell morphology, migration, polarity, and karyotype of bBMSCs were examined. The results showed that hypoxia (5% oxygen) enhanced colony formation and stress fiber synthesis of bBMSCs. Under the hypoxic culture conditions, the migration capacity and normal karyotype rate of bBMSCs were significantly improved (p < 0.05), which resulted in weakened cell polarity and enhanced karyotype stability in bBMSCs. In addition, it was significantly (p < 0.05) upregulated in the expression levels of HIF-TWIST signaling pathway axis-related genes (Hif-1, Hif-2, Twist, Snail, Slug, Fn1, N-cadherin, Collal). The HIF-TWIST axis of bBMSCs was also activated in hypoxia. Finally, it was more effective and easier to maintain the mesenchymal feature of bBMSCs in hypoxic conditions. These findings not only provide theoretical guidance to elucidate the detailed regulation mechanism of hypoxia on mesenchymal nature maintenance of bBMSCs, but also provide positive support to further establish the stable in vitro culture system of bBMSCs.