PPARγ Expression in Human Spermatozoa and Its Relationship with Seminal F2-Isoprostanes and Resolvin D1 in the Presence of Varicocele and Urogenital Infections

Peroxisome Proliferator-Activated Receptor Gamma (PPAR gamma) is a regulating agent in antioxidant response also involved in controlling inflammation. The impact of varicocele and urogenital infections on sperm PPAR gamma expression was studied. The PPAR gamma gene expression was investigated in spermatozoa of 26 normozoospermic men grouped according to their clinical conditions: normal semen parameters (N), normal semen parameters and varicocele (N + V), and normal semen parameters and urogenital infections (N + UI). Sperm PPAR gamma expression was correlated with F-2-isoprostanes (F-2-IsoPs), as markers of lipid peroxidation, and Resolvin D1 (RvD1), a pro-resolving mediator in inflammation. Sperm PPAR gamma expression was evaluated through comparative real-time PCR, and F-2-IsoPs and RvD1 were quantified in the seminal plasma via GC/NCI-MS/MS and immunoassay, respectively. PPAR gamma expression correlates positively with sperm morphology and vitality and negatively with F-2-IsoPs and RvD1. Sperm morphology positively correlates with vitality and negatively with F-2-IsoP and RvD1 levels. Despite the normozoospermia in the three examined groups, sperm morphology and PPAR gamma expression were significantly reduced in N + V and N + UI groups compared to the N group. Additionally, F-2-IsoP and RvD1 levels were elevated in N + V and N + UI patients. These data suggest that PPAR gamma expression is compromised by inflammation and lipoperoxidation, providing new insights to further explore new possibilities of targeted treatment of male infertility.