Nasal polyp epithelial cells serve as the primary initiating factors of airway inflammation. These cells regulate both innate and acquired immune responses in the upper respiratory tract. Recent research indicates that a complex interaction exists between these epithelial cells and pericytes. This crosstalk essentially mirrors the cellular dynamics observed in lower respiratory tract diseases. Consequently, understanding these interactions provides critical insights into the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP).

Interaction Between Nasal Polyp Epithelial Cells and Pericytes

Researchers recently established a co-culture model to examine how nasal polyp epithelial cells influence human microvascular pericytes. Specifically, they utilized house dust mite (HDM) extract to stimulate primary mucosal epithelial cells. The study demonstrated that HDM-stimulated epithelial cells significantly enhance the migration of pericytes. Interestingly, this effect was most pronounced in eosinophilic co-culture groups. Furthermore, the co-culture environment appeared to restore the migration ability of epithelial cells that had been previously impaired by HDM exposure. Therefore, these findings suggest a bidirectional relationship that maintains mucosal integrity while potentially driving remodeling.

Key Signaling in Nasal Polyp Epithelial Cells

Molecular analysis revealed that epithelial-pericyte communication triggers the upregulation of several inflammatory mediators. Specifically, pericytes in the co-culture system expressed high levels of Periostin (POSTN), Vascular Cell Adhesion Molecule-1 (VCAM-1), and CCL-5. These factors are well-known drivers of eosinophil recruitment and tissue fibrosis. Moreover, Western Blotting confirmed the activation of the PDGF/PI3K/AKT/NF-κB signaling pathway within the pericytes. This specific pathway acts as the molecular bridge that translates epithelial distress signals into pericyte-mediated inflammatory responses.

Clinical Implications for Airway Inflammation

The discovery of the PDGF/PI3K/AKT/NF-κB axis offers a new perspective on therapeutic targets for nasal polyposis. Since pericytes regulate vascular permeability and leukocyte extravasation, modulating their response could reduce tissue edema and inflammation. Additionally, the role of POSTN and VCAM-1 highlights how epithelial-pericyte interactions contribute to the persistent nature of Type 2 inflammation. Clinicians should monitor these emerging pathways as they may eventually lead to more personalized biological treatments for refractory chronic rhinosinusitis.

FAQ

How do nasal polyp epithelial cells contribute to inflammation?

They act as the first line of defense and release cytokines that activate other cell types, such as pericytes and immune cells, to initiate an inflammatory cascade.

What is the significance of the PDGF pathway in nasal polyps?

The PDGF/PI3K/AKT/NF-κB pathway facilitates communication between epithelial cells and pericytes, leading to the expression of factors like VCAM-1 that recruit inflammatory cells.

Can house dust mites trigger these cellular changes?

Yes, house dust mite (HDM) extract acts as a potent stimulator that damages the epithelial barrier and triggers the release of factors that promote pericyte migration and inflammation.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or a professional relationship. Always seek the advice of a qualified healthcare provider regarding any medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Cui N et al. Co-culture of mucosal epithelial cells of nasal polyps and pericytes and the expression and regulation of related factors. Int Arch Allergy Immunol. 2026 Feb 26. doi: 10.1159/000549978. PMID: 41746864.

2. Coste A et al. Epithelial cell proliferation in nasal polyps could be up-regulated by platelet-derived growth factor. Laryngoscope. 1996 May;106(5 Pt 1):578-83.

3. Jonstam K et al. Periostin, a biomarker in chronic rhinosinusitis with nasal polyps. Allergy. 2017 May;72(5):782-790.