Female urinary proteomics: New insight into exogenous and physiological hormone-dependent changes.

PURPOSE: In the frame of a research study on possible urinary markers related to physiological hormones cycle, 33 volunteer, healthy, normotensive fertile women were selected. Clinical parameters and renin-angiotensin-aldosterone system (RAAS) components were also investigated, on the basis of the well-known relation linking sex female hormones and renin and aldosterone levels.

EXPERIMENTAL DESIGN: A classic proteomic approach was applied to investigate urinary protein changes at different stages of menstrual cycle, specifically mid-cycle phase (G1), luteal phase (G2) and after 2 months of contraceptive therapy (G3). Analysis of urinary proteome was performed by SDS-PAGE, 2-D PAGE, Western blotting, and protein identification by HPLC-MS/MS.

RESULTS: In the four comparisons examined (G1 vs. G2; G1 vs. G3; G2 vs. G3 and G(G1+G2) vs. G3), a total of 115 protein spots were differentially represented among the subgroups. Data validation was performed by replicated experiments of immunoblotting.

CONCLUSIONS AND CLINICAL RELEVANCE: The present work highlights for the first time variations with menstrual cycle or estroprogestin pill of newly discovered, or never related, urinary proteins. In particular, possible protein markers could be useful for further applications in contraceptive target research and RAAS modulation-related topics.