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

The peroxisome proliferation-activated receptor gamma (PPARγ) 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 PPARγ. The functionality of the receptor was evidenced by 15-deoxy-12,14-prostaglandin J2 (PGJ2) and rosiglitazone (BRL) PPARγ-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 PPARγ on human sperm was confirmed by an irreversible PPARγ antagonist, GW9662. Our findings provide evidence that human sperm express a functional PPARγ whose activation influences sperm physiology. In conclusion, the presence of PPARγ 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. J. Cell. Physiol. 209: 977–986, 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]