Effect of Retinoic Acid in a Mouse Model of Allergic Rhinitis

Abstract

PurposeAll-trans retinoic acid (ATRA) modulates immune responses by affecting T cells. Several studies have revealed that allergic inflammation of the lower airways is negatively associated with the vitamin A concentration. However, the role of ATRA in allergic inflammation of the upper airways is unclear. We investigated the effects of ATRA in an allergic rhinitis mouse model.MethodsBALB/c mice except control groups (CON group) were sensitized with and challenged intra-nasally with Dermatophagoides farina (AR group). The ATRA groups were administered ATRA intraperitoneally. The steroid groups were administered steroid intranasally (ST group). Allergic symptoms and the average eosinophil number were counted. Cytokines and transcription factors were measured by Real-Time PCR and Western blotting. Der f-specific immunoglobulin E (IgE) was measured. Flow cytometry results of CD4+CD25+Foxp3+ T cells were analyzed.ResultsThe symptom scores were lower in the ATRA group than in the AR group and higher than in the CON group. The levels of IgE were lower in the ATRA group than in the AR group and higher than in the CON and ST groups. The levels of Foxp3, TGF-β, and IL-10 mRNA, as well as the percentage of CD4+CD25+Foxp3+ T cells, were higher in the ATRA group than in theAR group. In the ATRA group the levels of IFN-γ mRNA were higher, and the levels of GATA-3 and IL-4 mRNA, and ROR-γt were lower. In Western blotting analyses, the expression patterns of all factors, except Foxp3, showed similar to those of mRNA expression.ConclusionsATRA has anti-allergic effects in an allergic rhinitis model, and its underlying mechanisms mainly include the induction of regulatory T cells and the inhibition of Th2 responses.

Effect of Proparacaine in a Mouse Model of Allergic Rhinitis

“…In our study, OVA specific IgE, OVA specific IgG1, and OVA specific IgG2a were significantly increased with intraperitoneal OVA sensitization which did not decrease after intranasal treatment with steroid or PPC. This might be different from previous studies which reported intranasal treatment with steroid or other therapeutic materials lowered blood levels of OVA specific IgE [ 13 , 23 ]. Interestingly, as mentioned above, serum levels of IL-4 were lower in the PPC and CIC groups in comparison with AR group.…”

Effect of Proparacaine in a Mouse Model of Allergic Rhinitis

“…This might be different from previous studies which reported intranasal treatment with steroid or other therapeutic materials lowered blood levels of OVA specific IgE [13,23]. Interestingly, as mentioned above, serum levels of IL-4 were lower in the PPC and CIC groups in comparison with AR group.…”

Polarization of protease-activated receptor 2 (PAR-2) signaling is altered during airway epithelial remodeling and deciliation

“…The active metabolite of vitamin A, retinoic acid (R.A.), is involved in transcriptional control of ciliogenesis (36,41,42). R.A. has anti-allergic effects in mice (43,44) and in vitro cell models. Growing primary airway epithelial cells in the absence of R.A. induces a squamous phenotype (45).…”