Upregulation of the Vitamin D Receptor in the Nasal Mucosa of Patients With Allergic Rhinitis

Background and Objectives: Vitamin D modulates immunity, including that of allergic diseases, and plays its roles through contact with vitamin D receptors (VDR). Recent studies have shown that patients with allergic rhinitis have low systemic serum vitamin D level. However, the expression of VDR in local tissue such as human nasal mucosa has not been investigated. Our study demonstrated that, in nasal mucosa of normal controls and patients with allergic rhinitis. Materials and Methods: Nasal mucosa were harvested from twenty-five patients who had normal nasal mucosa and twenty-five patients with allergic rhinitis. After the total RNA isolation, we performed reverse transcriptase-polymerase chain reaction, immunohistochemical staining and western blot analysis. Results: VDR were expressed in submucosal glands and the superficial layer of epithelial cell, and that inflammatory cells are expressed more highly in the nasal mucosa of patients with allergic rhinitis compared to those without. In the mucosa of patients with allergic rhinitis, VDR expression level was upregulated compared to that in normal nasal mucosa. Conclusion: This findings suggest that VDR plays a role in the pathogenesis of allergic rhinitis. Additional research is needed to determine the mechanism and consequences of VDR upregulation.