Proteomic Study of Middle Ear Effusion and Its Clinical Application for Otitis Media with Effusion

BACKGROUND: Proteins found in middle ear effusion play crucial roles in the physiological and pathological processes of otitis media with effusion (OME), influencing the etiology and clinical characteristics of this disease. The qualitative and quantitative composition of these proteins depending on the underlying pathogenesis of middle ear effusion. Understanding their physiological and pathological functions is of great importance. METHODS: We collected samples from 19 volunteers diagnosed with OME. After offline separation using high-pH reversed-phase liquid chromatography (RPLC), the pooled sample was subjected to LC-MS/MS analysis to obtain a comprehensive profile of the OME proteome. Functional analysis was performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Ingenuity Pathway Analysis (IPA) annotations. Data-independent acquisition (DIA) technology was utilized to analyze samples and fix whether the OME proteome could replicate the pathophysiological features associated with this disease. We conducted a differential proteomic analysis between patients with simple OME and patients who had received radiotherapy. The radiotherapy-reduced group was further divided into two subgroups: nasopharyngeal carcinoma (NPC) and other types of carcinoma. Parallel reaction monitoring (PRM) technology was used for validation of 36 differentially expressed proteins (DEPs). RESULTS: A number of 732 proteins were identified in the OME proteome database. Among them, 527 proteins were quantified using peak intensity-based semi-quantification (iBAQ), covering a wide dynamic range of approximately 8 orders of magnitude. Based on the functional analysis, we proposed a hypothetical mechanism of OME. CONCLUSION: This study managed to put up an inclusive analysis of the OME proteome, establishing the first human OME proteome database. We focused on differential proteomic analysis among different groups to gain a more comprehensive concept of the OME proteome and search for meaningful biomarkers.