Platelet-rich plasma and ovarian quiescence: a bovine in vitro model for regeneration of the ovary

Context: Ovarian quiescence can be due to hormonal deficiency usually caused by apoptosis of granulosa cells responsible for oestrogen synthesis. Aim: This study evaluated the regenerative effect of platelet rich plasma (PRP) on bovine in vitro models to understand its effect on granulosa cells. Methods: Quiescent and healthy ovarian sections were cultured in the presence/absence of PRP for 72h and, at different times (0, 24, 48 and 72h), hematoxylin-eosin and immunohistochemical detection of Ki-67 were performed. Additionally, granulosa cells collected from healthy bovine ovaries were stressed with 100ng/mL of lipopolysaccharide (LPS) in presence/absence of PRP and evaluated at 0, 4, 8 and 24h for apoptosis by acridine orange and propidium iodide staining. Enzyme-linked immunosorbent assay tests were performed to evaluate oestrogen (E2) and anti-Müllerian hormone (AMH) concentrations on cultures of ovarian slices and granulosa cells. Key results: In slides of quiescent ovaries treated with PRP, a marked and widespread positivity to Ki-67 was expressed by 40-60% of the follicular wall cells at 48h of culture. Levels of E2 and AMH were significantly higher compared to untreated quiescent samples reaching the levels of healthy control samples. PRP counteracted the LPS effect and apoptosis (at 24h, there were 93.44±3.51% live cells with LPS+PRP compared to 37±1.32% with LPS) and significantly increased concentrations of E2 and AMH. Conclusions: PRP can stimulate granulosa cell proliferation and counteract inflammatory processes in vitro. Implications: This treatment could improve the reproductive ability of quiescent females.