High concentrations of GW9508 enhance sperm velocity in mice via peroxisome proliferator-activated receptor γ

In this study, we investigated the effects of GW9508, a well-known long-chain fatty acid receptor agonist, on mouse sperm function and its underlying target molecules. RT-PCR analysis detected mRNA expression of Gpr120 and Pparγ in mouse testes, whereas Gpr40 and Gpr119 expression was not observed. Sperm motility analysis revealed that exposure to high-concentration GW9508 (100 μM) significantly increased velocity parameters, including curvilinear velocity (VCL). A similar increase in sperm velocity was observed following treatment with the PPARγ agonist troglitazone, whereas the GPR120 agonist TUG891 had no effect on sperm motility. Furthermore, the PPARγ antagonist GW9662 abolished the motility-enhancing effects of GW9508 and troglitazone, whereas the GPR120 antagonist AH7614 did not alter these effects. Cytotoxicity analysis demonstrated that exposure to 100 μM GW9508 did not alter mitochondrial membrane potential, membrane integrity, or DNA fragmentation in mouse sperm. In addition, GW9508 did not promote capacitation-associated tyrosine phosphorylation or the acrosome reaction. Collectively, these findings indicate that high-concentration GW9508 enhances sperm velocity via a PPARγ-dependent pathway independently of GPR120 while exerting no detectable cytotoxic effects on sperm. This study reveals a previously unrecognized mechanism by which fatty acid-related signaling selectively regulates sperm motility and provides new insights into the molecular regulation of sperm velocity.