Serum Reproductive Hormone Profiles and Endometrial Expression of miR-16-5p, VEGF Gene, and Protein, and CD31-Positive Cells following Progesterone and EGCG Administration.

BACKGROUND: AngiomiRs, a group of microRNAs, target angiogenesis-related genes such as VEGF. Angiogenesis is crucial for endometrial receptivity and all stages of pregnancy. Research indicates that steroid concentrations can affect molecular structures linked to endometrial receptivity. This study aimed to investigate hormonal profiles and endometrial expression of miR-16-5p, VEGF gene/protein, and CD31-positive cell density in mice undergoing luteal phase support and EGCG administration before implantation. MATERIALS AND METHODS: Forty adult female mice were divided into four groups: control (no intervention), progesterone (1 mg/mouse of progesterone intraperitoneally [IP] for 3 consecutive days, 72 h after day 0), EGCG (5 mg/kg of EGCG at 0, 24, 48, and 72 h), and progesterone + EGCG groups. Enzyme-linked immunosorbent assay (ELISA) was employed for measuring the concentration of estrogen and progesterone. Gene expression analysis of miR-16-5p and VEGF was conducted using real-time polymerase chain reaction (PCR). VEGF protein levels were assessed through immunohistochemistry (IHC) and western blot analysis, and endometrial CD31-positive cell density was evaluated by IHC. RESULTS: The highest and lowest miR-16-5p expression and progesterone concentration were observed in the progesterone and EGCG groups, respectively. Endothelial cell density and VEGF protein increased in the progesterone group. Although EGCG treatment decreased VEGF protein CD31-positive cells, and progesterone levels. Estradiol levels notably declined in all treated groups. Changes in VEGF gene expression were not statistically significant. CONCLUSIONS: Exogenous progesterone or EGCG may influence endothelial cell proliferation by altering steroid hormone concentrations, miR-16-5p synthesis, and the post-transcriptional regulation of VEGF expression. However, further studies are required, particularly to explore other angiogenesis-related factors.