The expression of VEGF and VEGFR in endotoxin induced otitis media with effusion in rats

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.

Hypoxia in non-rapid eye movement sleep in children with otitis media with effusion

Objective

This study aimed to analyze the status of hypoxia in non-rapid eye movement (NREM) sleep in children with otitis media with effusion (OME).

Methods

A total of 232 children with OME and/or adenotonsillar hypertrophy were enrolled in this retrospective study between August 2020 and November 2021. Polysomnographic monitoring was carried out, and the differences in polysomnographic results between the experimental group (children with OME and adenotonsillar hypertrophy) and control group (children with adenotonsillar hypertrophy only) were compared.

Results

The lowest oxygen saturation level during sleep was significantly lower in the experimental group (n  =  36) than in the control group (n = 196). However, the apnea-hypopnea index, respiratory disorder index, apnea index, obstructive apnea index, obstructive apnea-hypopnea index, and mixed apnea-hypopnea index were significantly higher in the experimental group than in the control group. More importantly, the apnea-hypopnea index, the oxygen desaturation index, oxygen desaturation events, the average heart rate during NREM sleep, and the NREM stage in total sleep time were also significantly higher in the experimental group than in the control group.

Conclusions

Hypoxia during NREM sleep may affect the severity of OME in children.

Effect of Angiogenesis and Lymphangiogenesis in Diesel Exhaust Particles Inhalation in Mouse Model of LPS Induced Acute Otitis Media

Lymphangiogenesis and angiogenesis might have significant involvement in the pathogenesis of otitis media with effusion. This study investigated the effect of diesel exhaust particles (DEP) on inflammation and lymphangiogenesis in a mouse model of acute otitis media (AOM). BALB/c mice were injected with LPS and exposed to 100 µg/m³ DEP. The mice were divided into four groups: control (no stimulation), AOM, AOM + DEP, and DEP + AOM.

The effects of DEP inhalation pre- and post-DEP induction were estimated based on measurements of the auditory brainstem response, mRNA levels of lymphangiogenesis-related genes and cytokines, and histology of the middle ear. Cell viability of human middle ear epithelial cells decreased in a dose-response manner at 24 and 48 hours post-DEP exposure. DEP alone did not induce AOM. AOM-induced mice with pre- or post-DEP exposure showed thickened middle ear mucosa and increased expression of TNF-α and IL1-β mRNA levels compared to the control group, but increased serum IL-1β levels were not found in the AOM + Post DEP. The mRNA expression of TLR4, VEGFA, VEGFAC, and VEGFR3 was increased by pre-AOM DEP exposure.

The expression of VEFGA protein was stronger in the AOM + Post DEP group than in any other group. The expression of CD31 and CD45 markers in the mouse middle ear tissue was higher in the Pre DEP + AOM group than in the AOM group. This result implies that pre-exposure to DEP more strongly increases inflammation and lymphangiogenesis in a mouse model of acute otitis media.