# Sperm Motility Is Modulated by F4-Neuroprostane via the Involvement of Ryanodine Receptors

## TL;DR

This study shows that F4-Neuroprostane boosts sperm motility through ryanodine receptors, and blocking these receptors reduces motility.

## Contribution

The study demonstrates a novel lipid-based mechanism involving ryanodine receptors in regulating sperm motility.

## Key findings

- F4-NeuroPs significantly increased rapid progressive motility in sperm.
- Dantrolene reduced motility and altered acrosome status and RyR localization.
- RyRs are localized in the midpiece of sperm and are involved in motility regulation.

## Abstract

F4-Neuroprostanes (F4-NeuroPs), oxidative metabolites of docosahexaenoic acid, act as bioactive lipid mediators enhancing sperm motility and induce capacitation-like changes in vitro. Their biological action is proposed to involve sperm ion channels, in particular ryanodine receptors (RyRs), which regulate intracellular calcium homeostasis. We evaluated the effects of dantrolene, a RyR inhibitor, on motility and vitality of a selected spermatozoa at different concentrations (10, 30, 50, 100 μM). Then sperm motility, acrosome integrity, and RyR localization following co-incubation with dantrolene (D50 or D100 μM) and 4-/10-F4t-NeuroPs (7 ng) were investigated. Acrosomal status was assessed using Pisum sativum agglutinin (PSA) staining and RyR localization by immunofluorescence. D50 was identified as the minimum effective dose to induce significant reductions in sperm motility. F4-NeuroPs significantly increased rapid progressive motility versus controls. Co-incubation with F4-NeuroPs + D50 reduced rapid motility and increased in situ and circular movement. The acrosome staining appeared altered or absent to different percentages, and RyR localization was also seen in the midpiece. These findings suggested that F4-NeuroPs enhance sperm motility via RyR-mediated pathways, as confirmed by dantrolene inhibition. Accordingly, our results underscore the physiological relevance of RyRs in sperm function and suggest new insights into lipid-based mechanisms regulating sperm motility.