The role of interleukin 36γ in the epithelial-mesenchymal transition process of chronic rhinosinusitis: A pilot study

Serum proteomics identify CSF1R as a novel biomarker for postoperative recurrence in chronic rhinosinusitis with nasal polyps

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) presents a high rate of postoperative recurrence, but its recurrent mechanisms are not fully clarified. In this study, we aim to explore biomarkers associated with the recurrence of CRSwNP and shed light on the underlying recurrent mechanisms using serum proteomics.

Methods

A prospective cohort of CRSwNP patients was conducted, and serum samples were subjected to proteomic profiling. Participants were followed up for 2 years and divided into non-Recurrence and Recurrence groups and differentially expressed proteins (DEPs) were compared. The top 3 DEPs were validated in the serum and tissue samples in a validation cohort, and their predictive values for recurrence and their associations with macrophages were evaluated. In vitro, circulating macrophages were utilized to explore the influence of candidate proteins on macrophage polarization in underlying recurrent mechanisms of CRSwNP.

Results

Sixteen CRSwNP patients completed the follow-up schedule, including 10 patients in the non-Recurrence group and 6 patients in the Recurrence group. Serum proteomics revealed a distinctive protein expression profile between the 2 groups. A validation cohort comprising 51 non-recurrent and 24 recurrent CRSwNP patients was recruited. Enzyme-linked immunosorbent assay (ELISA) results revealed that circulating levels of CSF1R and CDC42 were significantly higher, and DHRS9 levels were lower in the Recurrence group in comparison with the non-Recurrence group. In addition, tissue CSF1R and CDC42 were identified to be enhanced in the Recurrence group compared to the non-Recurrence group. Receiver-operated characteristic (ROC) curves and Kaplan-Meier survival analysis suggest that both serum and tissue CSF1R were associated with the risk of postoperative recurrence. Tissue immunofluorescence (IF) revealed that CSF1R was enhanced in the tissues of patients with recurrence, especially in the mesenchymal region. Multiplex IF highlighted that CSF1R was significantly co-expressed with M2 macrophage markers. In vitro experiments confirmed that CSF1R overexpression promoted macrophage M2 polarization and cytokine production.

Conclusion

Serum proteomic signatures may affect postoperative recurrence in CRSwNP patients. CSF1R is a potential biomarker for predicting CRSwNP recurrence. Mechanistically, the recurrence of CRSwNP appears to involve the CSF1R-driven M2 polarization process.

Emerging Role of the IL-36/IL-36R Axis in Multiple Inflammatory Skin Diseases

IL-36 is a most recent member of the IL-1 cytokine family, primarily expressed at barrier sites of the body such as the skin, lungs, and intestine. It plays a vital role in inflammation and is implicated in the development of various cutaneous; intestinal; and pulmonary disorders, including psoriasis, inflammatory bowel disease, and chronic obstructive pulmonary disease. IL-36 comprises 4 isoforms: the proinflammatory IL-36α, IL-36β, and IL-36γ and the anti-inflammatory IL-36R antagonist. An imbalance between proinflammatory and anti-inflammatory IL-36 isoforms can contribute to the inflammatory fate of cells and tissues. IL-36 cytokines signal through an IL-36R heterodimer mediating their function through canonical signaling cacade, including the NF-B pathway. Prominent for its role in psoriasis, IL-36 has recently been associated with disease mechanisms in atopic dermatitis, hidradenitis suppurativa, neutrophilic dermatoses, autoimmune blistering disease, and Netherton syndrome. The major cutaneous source of IL-36 cytokines is keratinocytes, pointing to its role in the communication between the epidermis, innate (neutrophils, dendritic cells) immune system, and adaptive (T helper [Th]1 cells, Th17) immune system. Thus, cutaneous IL-36 signaling is crucial for the immunopathological outcome of various skin diseases. Consequently, the IL-36/IL-36R axis has recently been recognized as a promising drug target for the treatment of inflammatory disorders beyond psoriasis. This review summarizes the current update on IL-36 cytokines in inflammatory skin diseases.