Supplementation with asiatic acid during in vitro maturation improves porcine oocyte developmental competence by regulating oxidative stress

Lysine-specific demethylase 1 (LSD1) participate in porcine early embryonic development by regulating cell autophagy and apoptosis through the mTOR signaling pathway

Lysine-specific demethylase 1 (LSD1) stands as the pioneering histone demethylase uncovered, proficient in demethylating H3K4me1/2 and H3K9me1/2, thereby governing transcription and participating in cell apoptosis, proliferation, or differentiation. Nevertheless, the complete understanding of LSD1 during porcine early embryonic development and the underlying molecular mechanism remains unclear. Thus, we investigated the mechanism by which LSD1 plays a regulatory role in porcine early embryos. This study revealed that LSD1 inhibition resulted in parthenogenetic activation (PA) and in vitro fertilization (IVF) embryo arrested the development, and decreased blastocyst quality. Meanwhile, H3K4me1/2 and H3K9me1/2 methylase activity was increased at the 4-cell embryo stage. RNA-seq results revealed that autophagy related biological processes were highly enriched through GO and KEGG pathway analyses when LSD1 inhibition. Further studies showed that LSD1 depletion in porcine early embryos resulted in low mTOR and p-mTOR levels and high autophagy and apoptosis levels. The LSD1 deletion-induced increases in autophagy and apoptosis could be reversed by addition of mTOR activators. We further demonstrated that LSD1 inhibition induced mitochondrial dysfunction and mitophagy. In summary, our research results indicate that LSD1 may regulate autophagy and apoptosis through the mTOR pathway and affect early embryonic development of pigs.

Effect of asiatic acid supplementation in tris-extender on post-thaw functional competence, antioxidant enzyme activity and in vivo fertility of bull sperm

Reactive oxygen species at supra-physiological levels trigger oxidative stress during cryopreservation, which can be neutralised by incorporating suitable antioxidants into the semen extender medium. This study was intended to explore the effect of asiatic acid (AA) as an antioxidant in semen extender on frozen-thawed sperm quality and in vivo fertility of bull sperm. Semen was collected from Holstein Friesian bulls for 10 consecutive weeks (total ejaculates = 60). Semen was cryopreserved with a Tris citric acid egg yolk-based extender supplemented with 0 (control), 20, 40, 60, and 100 μM AA. The supplementation of the extender with 40 and 60 μM AA improved (p < 0.05) post-thaw motility kinematics, plasma membrane integrity, acrosome integrity, sperm viability, and DNA integrity of bull sperm. Mitochondrial membrane potential was high (p < 0.05) with 60 μM of AA concentration in extender media. The catalase activity in seminal plasma was maintained (p < 0.05) when semen was added with 20, 40, and 60 μM of AA. The in vivo fertility was found to be significantly high with the semen extended with 60 μM AA. Conclusively, this study showed that AA supplementation in semen extender significantly improved sperm motility kinematics and cell integrity, conserved antioxidant enzyme activity, and improved in vivo fertility.

Supplementation with Eupatilin during In Vitro Maturation Improves Porcine Oocyte Developmental Competence by Regulating Oxidative Stress and Endoplasmic Reticulum Stress

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a flavonoid derived from Artemisia plants that has beneficial biological activities, such as anti-apoptotic, anti-oxidant, and anti-inflammatory activities. However, the protective effects of eupatilin against oxidative stress and endoplasmic reticulum stress in porcine oocyte maturation are still unclear. To investigate the effect of eupatilin on the development of porcine oocytes after in vitro maturation and parthenogenetic activation, we added different concentrations of eupatilin in the process of porcine oocyte maturation in vitro, and finally selected the optimal concentration following multiple comparisons and analysis of test results using SPSS (version 17.0; IBM, Chicago, IL, USA) software. The results showed that 0.1 μM eupatilin supplementation did not affect the expansion of porcine cumulus cells, but significantly increased the extrusion rate of porcine oocyte polar bodies, the subsequent blastocyst formation rate, and the quality of parthenogenetically activated porcine embryos. Additionally, it reduced the level of reactive oxygen species in cells and increased glutathione production. Further analysis revealed that eupatilin supplementation could reduce apoptosis, DNA double-strand breaks, and endoplasmic reticulum stress. In conclusion, supplementation with 0.1 μM eupatilin during in vitro maturation improved oocyte maturation and subsequent embryo development by reducing oxidative stress and endoplasmic reticulum stress.

Ferulic Acid Enhances Oocyte Maturation and the Subsequent Development of Bovine Oocytes

Improving the quality of oocytes matured in vitro is integral to enhancing the efficacy of in vitro embryo production. Oxidative stress is one of the primary causes of quality decline in oocytes matured in vitro. In this study, ferulic acid (FA), a natural antioxidant found in plant cell walls, was investigated to evaluate its impact on bovine oocyte maturation and subsequent embryonic development. Bovine cumulus-oocyte complexes (COCs) were treated with different concentrations of FA (0, 2.5, 5, 10, 20 μM) during in vitro maturation (IVM). Compared to the control group, supplementation with 5 μM FA significantly enhanced the maturation rates of bovine oocytes and the expansion of the cumulus cells area, as well as the subsequent cleavage and blastocyst formation rates after in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT). Furthermore, FA supplementation was observed to effectively decrease the levels of ROS in bovine oocytes and improve their mitochondrial function. Our experiments demonstrate that FA can maintain the levels of antioxidants (GSH, SOD, CAT) in oocytes, thereby alleviating the oxidative stress induced by H2O2. RT-qPCR results revealed that, after FA treatment, the relative mRNA expression levels of genes related to oocyte maturation (GDF-9 and BMP-15), cumulus cell expansion (HAS2, PTX3, CX37, and CX43), and embryo pluripotency (OCT4, SOX2, and CDX2) were significantly increased. In conclusion, these findings demonstrate that FA supplementation during bovine oocyte IVM can enhance oocyte quality and the developmental potential of subsequent embryos.

Supplementation of SDF1 during Pig Oocyte In Vitro Maturation Improves Subsequent Embryo Development

The quality of in vitro matured oocytes is inferior to that of in vivo matured oocytes, which translates to low developmental capacity of embryos derived from in vitro matured oocytes. The developmental potential of in vitro matured oocytes is usually impaired due to oxidative stress. Stromal cell-derived factor-l (SDF1) can reduce oxidative stress and inhibit apoptosis. The aim of this study was to investigate the effects of SDF1 supplementation during pig oocyte in vitro maturation (IVM) on subsequent embryo development, and to explore the acting mechanisms of SDF1 in pig oocytes. We found that the IVM medium containing 20 ng/mL SDF1 improved the maturation rate of pig oocytes, as well as the cleavage rate and blastocyst rate of embryos generated by somatic cell nuclear transfer, in vitro fertilization, and parthenogenesis. Supplementation of 20 ng/mL SDF1 during IVM decreased the ROS level, increased the mitochondrial membrane potential, and altered the expression of apoptosis-related genes in the pig oocytes. The porcine oocyte transcriptomic data showed that SDF1 addition during IVM altered the expression of genes enriched in the purine metabolism and TNF signaling pathways. SDF1 supplementation during pig oocyte IVM also upregulated the mRNA and protein levels of YY1 and TET1, two critical factors for oocyte development. In conclusion, supplementation of SDF1 during pig oocyte IVM reduces oxidative stress, changes expression of genes involved in regulating apoptosis and oocyte growth, and enhances the ability of in vitro matured pig oocytes to support subsequent embryo development. Our findings provide a theoretical basis and a new method for improving the developmental potential of pig in vitro matured oocytes.