Introduction: IVF is one of the methods used for assisted reproduction. blastocyst cannot be reached by a certain percentage of the resulting embryos. According to the studies, 40 to 50% of the embryos of IVF cycles cannot reach the blastocyst stage and are stopped. Embryos stop on the third to fourth day after conception Embryos stopped before implantation are divided into three groups: type 1, which is between 2 and 4 cells, type 2, which is between 4 cells and 8 cells, and the third type, which is stopped at the primary morula stage, which type 1 is in the MZT, and the second and third types. They are disturbed at the level of glycolysis and oxidative phosphorylation. And they may be disturbed in the signaling pathways. Signaling pathways can be regulated by antioxidants. Melatonin is an antioxidant that, by activating the Pi3k signaling pathway involved in development, The signaling pathway is PI3k, which is activated by placing growth receptors on it and causes the conversion of PIP2 to PIP3 and then the activation of Akt groups. Akt inhibits the gsk3 pathway and then activates the unit pathway, which is involved in cell proliferation and self-renewal. and also through its antioxidant properties, It can cause the growth of human embryos that have been stopped.
Methods: In this study, with the consent of the subjects, other 72-hour human embryos available in the Embryology Department of the Royan Research Institute Clinic, which were clinically and microscopically used, were used. The sample collection period IR.ACECR.ROYAN.REC.1402.008 started after obtaining the code of ethics This study was conducted during three main phases. The first phase is melatonin dosing and choosing the best dose. The second phase is the culture of suspended embryos in the control group and experimental groups with the appropriate concentration obtained from the first phase in order to remove these embryos from the state of suspension and culture to the blastocyst stage The third phase, the evaluation of blastocyst embryos including the expression of OCT4, NANOG, SOX2, CDKN1A, and CCNA2 genes by q-Real-time PCR technique.
Results: Under typical IVF procedures, approximately 30% of embryos arrest development, but maintain a normal morphology and cell integrity, and do not show signs of disintegration. the embryos that were arrested on day 3 did not reach the point of forming a morula. Based on the study and the transcriptome data, there are several reasons for this event, which can be mentioned as the failure in the activation of the fetal genome, the delay in the deletion of maternal transcripts, the creation of reactive oxygen species, and aneuploidy. Until today, limited methods have been presented to deal with the stopping of the development of the embryo. Among these solutions, you can use the supplemental culture medium and the use of antioxidants, which increase the activity of mitochondria by dealing with and/or preventing damage. Oxidative stress, as well as the regulation of cellular signaling pathways, is used Melatonin caused the arrested embryos to reach the blastocyst Melatonin antioxidants with a pi3k-activating effect had a substantial impact on the development of arrested embryos. After treatment, 11/35 embryos recommenced development However, Similarly, while many (9/35, 25%) of the embryos that recommenced development, only 1 compacted, and only (6 /35 20%)made it to the blastocyst stage. We next looked at senescent and cell cycle–related genes that increased the expression of pluripotency genes significantly compared to the control group Expression of the cell cycle inhibitor CDKN1A had also not declined melatonin partially reactivated a normal developmental program in a minority of embryos and CDKNA1 cell cycle inhibitor gene had a significant decrease in expression in the treatment group compared to the control.
Conclusion: Melatonin increases conformational changes in MT2, and activation of the αi subunit leads to stimulation of PKG through guanylate cyclase. Also, it involves PKC and ErK1/2 complexes. ERK signaling regulates six basic cellular processes in response to extracellular cues. These processes include cell proliferation, cell survival, cell growth, cell metabolism, cell migration, and cell differentiation In fact, melatonin through the receptor. Mt1 activates the pi3k signaling pathway and its downstream pathway, the Erk pathway Melatonin can play a role in the development of 72-hour arrested human embryos to reach the blastocyst.