Effects of minimal persistent inflammation on nasal mucosa of experimental allergic rhinitis in guinea pigs / 中华耳鼻咽喉头颈外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To establish an animal model of minimal persistent inflammation (MPI) of allergic rhinitis in guinea pigs and to investigate the changes of nasal mucosa. The expression of transforming growth factor-beta1 (TGF-beta1) and matrix metalloproteinases-9 (MMP-9) were discussed.</p><p><b>METHODS</b>Thirty male Hartley guinea pigs were randomly divided into two groups MPI model group and control group randomly, with fifteen animals in each group. Guinea pigs from MPI model group were sensitized intraperitoneally by injection of suspension of ovalbumin (OVA) and aluminum hydroxide in 0.9% physiological saline. Then, repeated local booster sensitization with low concentration of OVA suspension into the nasal cavity was performed to establish MPI models. Alcian blue-periodic acid-Schiff (AB-PAS) staining and Masson's trichrome (MT) staining were used to determine the number of goblet cells and collagen deposition within the basement membrane of epithelium. The expression and distribution of TGF-beta1 and MMP-9 in nasal mucosa were estimated by double immunofluorescence under a confocal laser scan microscopy system.</p><p><b>RESULTS</b>Compared with the control group, the increased goblet cells (t = 13.720, P < 0.05) in nasal epithelium together with the increased collagen fibrils (t = 4.542, P <0.05) within the basement membrane of epithelium were observed in the MPI model group. There was nearly no expression of TGF-beta1, in the control group and the expression of MMP-9 was only found in the epithelium cell. In contrast, there was significantly higher expression of TGF-beta1 and MMP-9 (t = 25.218, P <0.05) in nasal mucosa of MPI model group than that in control group. TGF-beta1 mainly expressed in the epithelium cell, the infiltrated inflammatory cell and extracellular matrix, while MMP-9 expressed in the epithelium cell and the infiltrated inflammatory cell.</p><p><b>CONCLUSIONS</b>Long time MPI in allergic rhinitis resulted in some changes of tissue remodeling in nasal mucosa. TGF-beta1 and MMP-9 may play an important role in disease progression.</p>