A proteomics-based approach in Ménière’s disease Giuseppe Chiarella, Claudio Petrolo, Alfonso Scarpa, Giuliano Sequino, Giovanni Cuda, Ettore Cassandro

Diagnosis of Ménière’s disease (MD) is still widely based on clinical basis. Consequences are on inaccuracy in terms of epidemiology, diagnosis and treatment. We have used a proteomics-driven approach to identify potential biomarkers of MD. To this end, plasma was obtained from whole blood of 20 individuals previously diagnosed as suffering from MD, and compared to plasma from healthy donors. A depletion of the highly abundant proteins was performed in order to enhance the chance of detection of the less represented ones, therefore reducing the noise-background. Two-dimensional gel electrophoresis, followed by in-gel tryptic digestion of the selected spots and LC-MS/MS analysis, allowed us to identify a set of proteins whose expression appears to be differentially modulated in patients vs controls. In particular: complement factor H and B, fibrinogen alpha and gamma chains, beta-actin and pigment epithelium derived factor are over expressed; on the other hand, the levels of beta-2 glycoprotein-1, vitamin D binding protein and apolipoprotein-1 are significantly decreased in the plasma of MD-affected individuals. Even though preliminary and not necessarily linked directly to the molecular pathogenesis of the disease, our original findings suggest that a molecular signature, represented by the plasma protein profile previously described, might represent a potentially powerful, innovative and not invasive tool for early diagnosis and clinical management of MD patients. Moreover, our findings uncover a potential starring role for some proteins in the development and fate of this frustrating disease, whose pathogenesis still remains unclear.