Effects of intranasal interferon gamma on transforming growth factor-β1/Smad in rats with allergic rhinitis / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of intranasal interferon gamma (IFN-γ) on nasal mucosa remodeling and expression of transforming growth factor-β1 (TGF-β1), Smad2, Smad3, Smad7 in allergic rhinitis (AR) rat model.</p><p><b>METHODS</b>Ovalbumin (OVA) and aluminum hydroxide were used to construct the AR model. Thirty AR rats were randomly divided into positive control group (group B, n = 10), IFN-γ treatment group (group C, n = 10) and negative control group (normal rats, n = 10). After the AR models were built, 50 µl PBS, 1 µg IFN-γ was dropped into the nasal cavity of each rat in group B and group C, from the fouth week to tenth week, twice a week. The nasal mucosa was collected on day 71 in order to observe the pathologic changes, and the expression of TGF-β1, TGF-β1 mRNA, Smad2 mRNA, Smad3 mRNA and Smad7 mRNA by immunohistochemistry and reverse transcriptase-polymerase chain reaction.</p><p><b>RESULTS</b>Decreases of TGF-β1, Smad2 and Smad3 mRNA were seen in nasal tissue of group C (0.59 ± 0.04, 0.39 ± 0.08, 0.46 ± 0.15) as compared with group B (0.82 ± 0.12, 0.70 ± 0.18, 0.95 ± 0.26), the differences were significant (q value were 3.15, 4.47, 3.03, all P < 0.05). The levels of Smad7 mRNA expression increased significantly (q = 2.98, P < 0.05) in group C (0.31 ± 0.05) as compared with group B (0.25 ± 0.06). Immunohistochemistry showed significant decrease of TGF-β1 expression in the nasal tissue of group C much lesser than that in group B.</p><p><b>CONCLUSIONS</b>Intranasal IFN-γ could decrease the expression of TGF-β1, TGF-β1 mRNA, Smad2 mRNA, Smad3 mRNA, increase the expression of Smad7 mRNA in AR rats model and inhibit the nasal mucosa remodeling.</p>

Treatment of allergic rhinitis rats by intranasal interferon gamma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the effects and mechanism of intranasal interferon gamma (IFN-gamma) in the treatment of allergic rhinitis.</p><p><b>METHODS</b>Ovalbumin (OVA) absorbed to aluminum hydroxide was used to construct the allergic rhinitis model (group C), and the normal control group (group A), the allergic rhinitis model group (group B) and beclomethasone dipropionate group (group D) consisted of 8 rats for each. PBS 50 microl was absorbed to group B, IFN-gamma 1 microg was absorbed to group C and beclomethasone dipropionate 3.5 microg was absorbed to group D on day 31 to day 38 once daily once nasal cavity. The nasal lavage fluid was collected on day 39, and the cellular constituents, levels of interleukin-4 (IL-4), interleukin-5 (IL-5) and IgE were determined, together with the pathologic changes and expression of GATA-3 were observed.</p><p><b>RESULTS</b>Decrease of eosinophils [(0.005 +/- 0.003) x 10(4)/ml, x +/- s] was seen in nasal lavage fluid of group C as comparing with group B [(0.225 +/- 0.060) x 10(4)/ml, (P < 0.01)], and the levels of IL-4 (7.8 +/- 3.5) pg/ml and IL-5 (12.5 +/- 4.3) pg/ml decreased significantly in comparing with group B (P < 0.01). The serum levels of total IgE (38.5 +/- 9.6) microg/ml and ovalbumin-specific IgE (19.8 +/- 5.4) IU/ml decreased significantly in comparing with those of group B (P < 0.01). In group B, mucosal congestion and edema thickening with inflammatory cells infiltration mainly of eosinophils; in group C, the above mentioned changes were much more ameliorated. Immunohistochemistry showed significant increase of GATA-3 expression in the nasal tissue of group B but much lesser than that in group C.</p><p><b>CONCLUSIONS</b>IFN-gamma can inhibit the composition of IL-4 and IL-5, and inhibit the airway inflammation with eosinophilic infiltration and the serum levels of total IgE and ovalbumin specific IgE, probably through the mechanism of restraining the Th2 reaction by blockade of GATA-3 expression in the nasal tissue.</p>