Application of proteomics to the study of polycystic ovary syndrome

Background: Clinical proteomics consists of qualitative and quantitative profiling of proteins present in clinical specimens such as body fluids or tissues, with the aim of discovering novel proteins and cellular pathways associated with the disease of interest. Aim: To review the proteomic studies conducted to date that addressed different aspects of the pathogenesis of polycystic ovary syndrome (PCOS). Methods: Descriptive review of studies that applied proteomic techniques to the study of PCOS. Published articles were identified using the Entrez-PubMed online search facilities. Results: Most studies conducted to date focused on protein variations in plasma and different target tissues. Plasma proteomics analysis revealed that PCOS associates changes in protein expression in several acute-phase response proteins. Moreover, some of these molecules play major roles in iron metabolism and low-grade chronic inflammation. Studies using omental adipose tissue from morbidly obese women with or without PCOS revealed differences in abundance of proteins that may be involved in lipid and glucose metabolism, oxidative stress processes, and adipocyte differentiation. Moreover, identification of differentially expressed proteins in ovarian tissue, granulosa cells or T lymphocites may help to characterize more clearly some aspects of this disorder. Conclusions: Although the application of proteomic techniques to the study of PCOS is in its early infancy, studies conducted to date highlight its heterogeneous nature. Aside from androgen excess, several pathways related to intermediate metabolism, oxidative stress processes, inflammation and iron metabolism appear to be involved in the pathophysiology of PCOS.