PLATELET-RICH PLASMA INCREASES HIF1a AND HIF2a IN ENDOMETRIUM AFFECTING LIVE BIRTH RATES IN MURINE ASHERMAN’S SYNDROME MODEL

Abstract

Women with refractory thin endometrium suffering from recurrent implantation failure (RIF) do not have many effective treatment options. Platelet-rich plasma (PRP) has been noted to be a possible breakthrough for these patients in several clinical studies. Also, hypoxia-inducible factor 1-alpha (HIF1a) and HIF2a are recently being studied to have some connection with endometrial function. The objective of this study was to find out the underlying mechanism of PRP acting on refractory endometrium and its possible relationship with HIF1a/HIF2a. Murine Asherman’s syndrome (AS) models were made by inducing damage to the uterine horns and human PRP obtained from 6 RIF patients was applied by intrauterine injection at day 7 after injury. RT-PCR analyses and western blotting of fibrosis, angiogenic markers and embryo invasion related markers from the mouse endometrial specimen were done at day 7 after PRP treatment. Cell migration study (scratch test) was done to see the recovery rate of the damaged human endometrial cell after PRP treatment. Implantation and live birth rates were compared between mouse AS model with and without PRP treatment. T-test was used for statistical analysis with SPSS ver.26. RT-PCR analyses showed significant decreases in fibrosis markers (COL1a1, p = 0.041; TIMP1, p = 0.027; TGF-b1, p = 0.004; TNF-a, p = 0.047) and significant increases in angiogenic markers (VEGF-a, p = 0.047; ANG-1, p = 0.015; HGF p = 0.031) including HIF1a (p = 0.023) and HIF2a (p = 0.042). The embryo invasion related markers including LIF (p = 0.001), MT2-MMP (p = 0.001), LOX (p < 0.001), and ADM (p < 0.001) were significantly increased after PRP treatment in AS models. Western blot also revealed similar results as RT-PCR. Cell migration study showed significantly higher migration rate for PRP group compared to control. The number of implantation sites and live birth rates were significantly greater in PRP group compared to AS without treatment. No live pup was delivered from AS without PRP mouse group. The embryo and placenta weights were significantly greater in PRP treated group (p < 0.001). PRP has shown to improve the damaged endometrium by decreasing fibrosis, increasing angiogenesis and embryo invasion markers. HIF1a and HIF2a seem to be the key factors that are increased by PRP. In return, they affect the embryo implantation by inducing LOX, MT2-MMP in endometrial epithelial detachment, and LIF which regulates embryo attachment.