Proteomic Study Identifies Glycolytic and Inflammation Pathways Involved in Recurrent Otitis Media

The expression of Nrf2 and TLRs in ear effusion in children with different types of otitis media and their relationship with inflammatory factors

OBJECTIVE

This study aimed to analyze the differences in the expression of Toll-like receptors (TLRs) and nuclear factor erythroid 2-related factor 2 (Nrf2) in ear effusion in children with different types of otitis media (OM), to elaborate the relationship between the expression of TLRs and Nrf2 in ear effusion and the pathogenesis of OM, and to explore the relationship between the two indicators and pro-inflammatory cytokines in children with OM, thereby laying a scientific foundation for revealing the underlying molecular mechanisms of the progression of different types of OM.

METHODS

A total of 73 children with OM who were treated in our hospital from March 2019 to July 2021 were selected as the study subjects. By using the cross-sectional investigation method, participants were divided into three groups according to the different pathological types, including the secretory OM group (30 cases), the chronic suppurative OM group (27 cases), and the cystic lesional OM group (16 cases). The levels of Nrf2, TLR2, TLR4 and proinflammatory cytokines [interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), transforming growth factor-β 1(TGF-β1), procalcitonin (PCT) and interleukin-1β (IL-1β)] were detected in ear effusion of children with different types of OM. Linear regression was used to analyze the correlation between the Nrf2, TLR2 and TLR4 expression levels and pro-inflammatory cytokines in ear effusion.

RESULTS

The expression levels of TNF-α and PCT in the ear effusion of the children under 3 years old were significantly higher than that of the children between 3 and 5 years old and that of the children between 6 and 8 years old (all P < 0.001). The mRNA levels of Nrf2, TLR2 and TLR4 in the ear effusion of the children from the chronic suppurative OM group were higher than these from the secretory OM group (P < 0.001, P = 0.008 and P = 0.021). The mRNA levels of Nrf2, TLR2, and TLR4 in the ear effusion of the children from the cystic lesional OM group were higher than those from the chronic suppurative OM group (P < 0.001, P = 0.029 and P = 0.018). A prominent increase in the concentrations of IFN-γ, TNF-α, TGF-β1, PCT and IL-1β was found in the ear effusion of children from the chronic suppurative OM group compared to these from the secretory OM group (P = 0.021, P = 0.044, P = 0.048, P = 0.004 and P = 0.001). The concentrations of IFN-γ, TNF-α, TGF-β1, PCT and IL-1β in the ear effusion of the children from the cystic lesional OM group were markedly increased as compared with these from the chronic suppurative OM group (P < 0.001, P = 0.004, P = 0.003, P < 0.001 and P < 0.001). Nrf2, TLR2 and TLR4 were taken as independent variables, and inflammatory indexes, including IFN-γ, TNF-α, TGF-β1, PCT and IL-1β were used as dependent variables for the linear regression analysis. The results showed that Nrf2, TLR2 and TLR4 were positively correlated with the secretion levels of pro-inflammatory cytokines after adjusting for age, sex, course and the OM classification (all P < 0.05).

CONCLUSION

The expressions of Nrf2, TLR2 and TLR4 in the ear effusion of children with different types of OM gradually increased with the severity of the disease, these were significantly positively correlated with the pro-inflammatory cytokines of the children. Nrf2/TLR signaling pathway maintained chronic inflammation in OM, induced damage of middle ear tissue, and promoted the transition from acute OM to chronic OM.

Otitis media: Interactions between host and environment, immune and inflammatory responses

OBJECTIVE

To review and highlight progress in otitis media (OM) research in the areas of immunology, inflammation, environmental influences and host-pathogen responses from 2019 to 2023. Opportunities for innovative future research were also identified.

DATA SOURCES

PubMed database of the National Library of Medicine.

REVIEW METHODS

Key topics were assigned to each panel member for detailed review. Search of the literature was from June 2019 until February 2023. Draft reviews were collated, circulated, and discussed among panel members at the 22nd International Symposium on Recent Advances in Otitis Media in June 2023. The final manuscript was prepared and approved by all the panel members.

CONCLUSIONS

Important advances were identified in: environmental influences that enhance OM susceptibility; polymicrobial middle ear (ME) infections; the role of adaptive immunity defects in otitis-proneness; additional genes linked to OM; leukocyte contributions to OM pathogenesis and recovery; and novel interventions in OM based on host responses to infection. Innovative areas of research included: identification of novel bacterial genes and pathways important for OM persistence, bacterial adaptations and evolution that enhance chronicity; animal and human ME gene expression, including at the single-cell level; and Sars-CoV-2 infection of the ME and Eustachian tube.

Small extracellular vesicles from malignant ascites of patients with advanced ovarian cancer provide insights into the dynamics of the extracellular matrix

The exact role of malignant ascites in the development of intraperitoneal metastases remains unclear, and the mechanisms by which extracellular vesicles (EVs) promote tumor progression in the pre-metastatic niche have not been fully discovered. In this study, we characterized ascites from high-grade epithelial ovarian cancer patients. Small-EVs (30-150 nm) were isolated from two sources-the bulk ascites and the ascitic fluid-derived tumor cell cultures-and assessed with a combination of imaging, proteomic profiling, and protein expression analyses. In addition, Gene Ontology and pathway analysis were performed using different databases and bioinformatic tools. The results proved that the small-EVs derived from the two sources exhibited significantly different stiffness and size distributions. The bulk ascitic fluid-derived small-EVs were predominantly involved in the complement and coagulation cascade. Small-EVs derived from ascites cell cultures contained a robust proteomic profile of extracellular matrix remodeling regulators, and we observed an increase in transforming growth factor-β-I (TGFβI), plasminogen activator inhibitor 1 (PAI-1), and fibronectin expression after neoadjuvant chemotherapy. When measured in the two sources, we demonstrated that fibronectin exhibited opposite expression patterns in small-EVs in response to chemotherapy. These findings highlight the importance of an ascites cell isolation workflow in investigating the treatment-induced cancer adaption processes.