Introduction:
Due to the fact of limited histological access to the cochlea, most causes of inner
ear disorders are unknown or poorly understood and also diagnostic methods are limited.
The development of a mass spectrometric proteome analysis of human perilymph (PL)
opens a new perspective for the evaluation of PL specific biomarkers.
Methods:
Human PL samples were obtained intraoperatively during CI-surgeries. The identification
of PL proteins was performed by Shot-gun proteomics (Orbitrap Massenspektrometer,
Thermo Fisher Scientific) and quantified using Max Quant Software. The identified
proteins were analyzed by IPA (Ingenuity pathway analysis) and the results obtained
were correlated to the patients' prae- und postoperative audiological data.
Results:
41 perilymph samples were analyzed by mass spectrometry revealing in 878 different
proteins in total. Ingenuity pathway analysis of PL proteins delineated putative intracellular
pathways connected to BDNF (brain-derived neurotrophic factor) signaling in the inner
ear. A correlation of protein quantification to the patients' audiological data is
currently in analysis.
Conclusions:
In-depth proteome analysis of human PL opens a window for understanding molecular
pathology of the inner ear. The neurotrophin BDNF has been implicated with the health
of the auditory nerve and the growth of neurons at all. The method is feasible to
develop new therapeutic strategies to improve inner ear health which could increase
cochlear implant performance.