Peroxisome proliferator-activated receptor (PPAR)γ is expressed by human spermatozoa:: Its potential role on the sperm physiology

The peroxisome proliferation-activated receptor gamma (PPAR gamma) is mainly expressed in the adipose tissue and integrates the control of energy, lipid, and glucose homeostasis. The present study, by means of RT-PCR, Western blot, and immunofluorescence techniques, demonstrates that human sperm express the PPAR gamma. The functionality of the receptor was evidenced by 15-deoxy-12,14-prostaglandin J(2) (PGJ2) and rosiglitazone (BRL) PPAR gamma-agonists that were tested on capacitation, acrosome reaction, and motility. Both treatments also increase AKT phosphorylations and influence glucose and lipid metabolism in sperm. The specificity of PGJ2 and BRL effects through PPAR gamma on human sperm was confirmed by an irreversible PPAR gamma antagonist, GW9662. Our findings provide evidence that human sperm express a functional PPAR-gamma whose activation influences sperm physiology. In conclusion, the presence of PPAR gamma in male gamete broadens the field of action of this nuclear receptor, bringing us to look towards sperm as an endocrine mobile unit independent of the systemic regulation.