Melatonin accelerates the developmental competence and telomere elongation in ovine SCNT embryos

Abstract

SCNT embryos suffer from poor developmental competence (both in vitro and in vivo) due to various defects such as oxidative stress, incomplete epigenetic reprogramming, and flaws in telomere rejuvenation. It is very promising to ameliorate all these defects in SCNT embryos by supplementing the culture medium with a single compound. It has been demonstrated that melatonin, as a multitasking molecule, can improve the development of SCNT embryos, but its function during ovine SCNT embryos is unclear. We observed that supplementation of embryonic culture medium with 10 nM melatonin for 7 days accelerated the rate of blastocyst formation in ovine SCNT embryos. In addition, the quality of blastocysts increased in the melatonin-treated group compared with the SCNT control groups in terms of ICM, TE, total cell number, and mRNA expression of NANOG. Mechanistic studies in this study revealed that the melatonin-treated group had significantly lower ROS level, apoptotic cell ratio, and mRNA expression of CASPASE-3 and BAX/BCL2 ratio. In addition, melatonin promotes mitochondrial membrane potential and autophagy status (higher number of LC3B dots). Our results indicate that melatonin decreased the global level of 5mC and increased the level of H3K9ac in the treated blastocyst group compared with the blastocysts in the control group. More importantly, we demonstrated for the first time that melatonin treatment promoted telomere elongation in ovine SCNT embryos. This result offers the possibility of better development of ovine SCNT embryos after implantation. We concluded that melatonin can accelerate the reprogramming of telomere length in sheep SCNT embryos, in addition to its various beneficial effects such as increasing antioxidant capacity, reducing DNA damage, and improving the quality of derived blastocysts, all of which led to a higher in vitro development rate.

Global DNA methylation, DNA methyltransferase and stress‐related gene expression in ovine oocytes and embryos after exposure to metabolic stressors

“…In the future it would be interesting to focus on the DNA methylation levels of the selected genes (e.g., SOD1, SOD2) as well as on the genome-wide methylation pattern and the relationships with the gene expression. et al, 2018), but also by somatic cell cloning (Fang et al, 2020;Gorczyca et al, 2021;Nadri et al, 2022;Wiater et al, 2021).…”

“…Tracking the changes in epigenomic and transcriptomic signatures of in vitro‐matured ewe oocytes and corresponding IVF‐derived embryos that have undergone the exposure to a variety of nutritional and metabolic stressors might contribute to a better understanding the molecular interplay between pro‐ and antioxidative events and the relative abundances of DNMT mRNA transcripts. Exploring the above‐indicated interplay might result in the improved developmental capabilities and quality parameters noticed for ovine and other mammalian embryos produced not only by gamete coincubation‐mediated IVF (Anzalone et al, 2021; Gorczyca et al, 2022) or intracytoplasmic sperm injection (ICSI)‐mediated IVF (Ramírez‐Agámez et al, 2023; Ressaissi et al, 2021; Shirazi et al, 2018), but also by somatic cell cloning (Fang et al, 2020; Gorczyca et al, 2021; Nadri et al, 2022; Wiater et al, 2021).…”

Regulation of proteolysis in bovine cumulus cells with possible inclusion of proton pump activators

“…Furthermore, this seems to be positively correlated with molecular symptoms of PI3K/Akt and MAPK‐dependent cytoplasmic maturation and its synchronization with nuclear/meiotic maturation of in vitro cultured bovine oocytes. Therefore, comprehensively deciphering the above‐indicated molecular pathways characteristic of IVM‐derived COCs in cattle and other mammalian species might provide an abundant source of nuclear recipient oocytes for such novel assisted reproductive technologies as IVF by either gamete co‐incubation or intracytoplasmic sperm injection (Ashibe et al, 2019; Gorczyca et al, 2022; Jang et al, 2010; Santos et al, 2014) and cloning by somatic cell nuclear transfer (Moradi‐Hajidavaloo et al, 2023; Nadri et al, 2022; Samiec et al, 2012; Skrzyszowska & Samiec, 2021).…”

Developmental competence of IVF and SCNT goat embryos is improved by inhibition of canonical WNT signaling

“…Then, the oocyte-cell couplets were activated using ionomycin (5 μM) for 1 min and then cultured in 2 mM 6-DMAP at 38.5°C, 6.5% CO2, and maximum humidified atmosphere for 2 h under mineral oil. Finally, SCNT embryos were cultured in mSOF + for 7 days at 38.5°C, 6.5% CO2, 5.5% O2, and humidified atmosphere under mineral oil [ 47 ]. The SCNT blastocysts were used for evaluating the mRNA and protein expression of ß-CATENIN /ß-CATENIN (experiment 3).…”