Changes in the transcriptomic profile of cumulus cells under the influence of pre-incubation of human oocytes in patients treated in ART cycles
In this study, we tried to find out if the pre-incubation of the cumulus-oocyte complex can lead to better cumulus cell (CCs) function and higher oocyte quality by changing the transcriptomic profile of CCs. For this purpose, 140 cumulus cell samples were isolated from 12 participants and divided into two groups based on pre-incubation time. In the T0 group, the cumulus-oocyte complex was immediately dissected to separate the CCs from around the oocytes. In the T2 group, dissection and preparation of CCs were done after 2 hours of incubation. Then, the transcriptomic profile of the CCs of the non-pre-incubation group (T0) was compared to the 2-hour pre-incubation group (T2). 70 samples were placed in each group. 40 samples from each group were used for RNA-Sequencing and the remaining 30 samples of each group were used to confirm RNA-Sequencing results via qRT-PCR. The CCs transcriptome analysis showed 17 genes were downregulated and 22 genes upregulated in the T2 group compared to the T0 group. Also, the pathways related to ATP production (oxidative phosphorylation, electron transport chain, and Mitochondrial complex I assembly model OXPHOS system), TNF-alpha signaling pathway, and glucocorticoid receptor pathway enriched in the T2 group compared to the T0 group. Also, the TGF-ß pathway was decreased in the T2 group compared to the T0 group. This study showed that 2 hours' pre-incubation leads to changes in important pathways in CCs, which has a positive effect on oocyte quality. 2 hours' pre-incubation may lead to a better support of the CCs to the oocyte and thus to a more complete maturation of the oocyte. Overall design: There is a difference of opinion about the time of pre-incubation, and because the direct examination of the human oocyte is not ethical, in this study, the changes in the transcriptomic profile of cumulus cells (CCs) with zero and T2 pre-incubation were investigated. 140 cumulus cell samples were isolated from 12 participants and divided into two groups based on pre-incubation time. In the T0 group, cumulus-oocyte complex was immediately dissected to separate the CCs from around the oocytes. In the T2 group, dissection and preparation of CCs were done after 2 hours of incubation. 70 samples were placed in each group. 40 samples from each group were used for RNA-Sequencing and the remaining 30 samples of each group were used for confirmation of RNA-Sequencing results via qRT-PCR.