ECE2023 Poster Presentations Reproductive and Developmental Endocrinology (108 abstracts)
1Unit of Endocrinology-University of Modena and Reggio Emilia, Department of Biomedical, Metabolic and Neural Sciences, Modena, Italy; 2International Ph.D. School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Modena, Italy; 3Clinica Valle Giulia, GeneraLife IVF, Rome, Italy; 4University of Urbino Carlo Bo, Department of Biomolecular Sciences, Urbino, Italy; 5Center for Genomic Research-University of Modena and Reggio Emilia, Modena, Italy; 6Azienda Ospedaliero-Universitaria di Modena-Baggiovara Hospital, Department of Medical Specialties, Modena, Italy
In assisted reproduction, poor ovarian response to controlled ovarian stimulation (COS) leads to poor oocyte yield and depends on the genetic background. We compared the expression of key-genes, coding proteins regulating follicular development, between small (<10 mm) and large ovarian follicles (>16 mm), assuming the size as a hallmark of follicle maturation and oocyte fate. Twenty-two patients undergoing COS were enrolled in a fertility clinics. Granulosa cells and follicular fluids (FFs) were grouped according to size of ovarian follicles (small follicles, SFs, diameter <10 mm, n=22; large follicles, diameter, LFs, >16 mm, n=22) and collection in the antral or luteal stage. Gene expression was analyzed by digital droplet PCR, while testosterone (T) and estradiol (E2) levels were measured by homogeneous time-resolved fluorescence. Results were matched with clinical data by principal component analysis (PCA). Ethics Committee approval was obtained, and statistical analysis was performed using Mann-Whitneys U-test (P<0.05; means±SEM). FSHR and GPER gene expression was higher in SFs than LFs, supporting their role in promoting follicular dominance via activation of proliferative signals (P<0.05; FSHR-LFs: 1x10-3±0.1x10-3 fold/housekeeping gene expression; FSHR-SFs: 4.6x10-3±1.1x10-3; GPER-LFs: 2.8x10-3±0.3x10-3; GPER-SFs: 7.8x10-3±1.7x10-3). FSHR/GPER gene expression ratio resulted to be lower in LFs than SFs, indicating the potential to counteract apoptotic signals linked to FSHR overexpression (P<0.0001; FSHR/GPER-SFs: 1.065±0.3 fold/housekeeping gene expression ratio; FSHR/GPER-LFs: 0.37±0.052). Marked CCND2 and AMHR2 expression were found in SFs as well, indicating cell proliferation (P<0.05; CCND2-LFs: 0.1±8x10-3 fold/housekeeping gene expression; CCND2-SFs: 0.15±18x10-3; AMHRII-LFs: 5x10-3±0.8x10-3; AMHRII-SFs: 8x10-3±1.3x10-3). No different CYP19A1, LHCGR, XIAP and TP53 gene expression was found between SFs and LFs (P≥0.05). In FFs, higher T levels were detected in LFs vs SFs (P<0.05; SFs: 1.7x10-9±1.3x10-10 hormone level/total protein amount; LFs: 2.2x10-9±2x10-10) while not significantly different E2 levels were detected (P≥0.05). In vitro data were matched with follicular diameter by PCA, revealing that LFs are a sub-cluster of SFs data, suggesting higher gene expression variability in SFs vs LFs. Heatmap hierarchical clustering revealed inverse relationship between AMHR2 and CYP19A1 expression levels. CYP19A1, FSHR and CCND2 were downregulated in LFs while upregulated in SFs, oppositely to what observed for LHCGR and GPER. XIAP and TP53 have similar expression levels in SFs and LFs. The present study confirms different expression of follicle maturation genetic markers.