Silencing STAT6 with siRNA prevents development of eosinophilic chronic rhinosinusitis: an experimental study
10.3760/cma.j.cn115330-20230608-00720
- VernacularTitle:siRNA沉默STAT6抑制嗜酸粒细胞性慢性鼻窦炎产生的实验性研究
- Author:
Hongqi WEI
1
;
Zhengwen ZHU
;
Hongyu XING
;
Zhiyong LIU
;
Zhongsheng CAO
;
Longjiang XU
;
Jisheng LIU
Author Information
1. 苏州大学附属第二医院耳鼻咽喉科，苏州 215004
- Keywords:
Sinusitis;
Eosinophil;
Th2 immune response;
Signal transducer and activator of transcription 6;
Small interfering RNA
- From:
Chinese Journal of Otorhinolaryngology Head and Neck Surgery
2023;58(11):1102-1111
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate whether silencing signal transducer and activator of transcription 6 (STAT6) with siRNA can inhibit eosinophilic inflammation of sinonasal mucosa in a mouse model of eosinophilic chronic rhinosinusitis (ECRS).Methods:The study was conducted from March to September in 2022. Forty-eight female BALB/c mice were randomly divided into four groups: the control group, the Vehicle (transfection reagent)-treated group, the Scramble siRNA (Control siRNA)-treated group, and the STAT6 siRNA-treated group, with twelve mice in each group. An ovalbumin (OVA)-staphylococcal enterotoxin B (SEB)-induced ECRS murine model was established. SiRNA prepared in Lipofectamine was locally administered to the nasal cavity. After administration, samples of the peripheral blood and sinonasal mucosa were collected. Eosinophils in peripheral blood were detected by hematology analyzer. Total and OVA-specific IgE (OVA-sIgE) in serum were detected by enzyme-linked immunosorbent assay (ELISA). Mucosal levels of cytokines and chemokines, including interleukin (IL)-5, IL-17A, interferon-γ (IFN-γ) and eotaxin-1, were also measured using ELISA. Mucosal histological changes of eosinophil infiltration were examined using hematoxylin, and eosin staining, and tissue eosinophil count was performed using a microscope under a high-power field (HPF). Tissue expression of STAT6 and phosphorylated STAT6 (p-STAT6) was detected with the western blot method. Immunofluorescence staining was used to localize the expression of p-STAT6 in sinonasal mucosa. Statistical analysis was conducted using SPSS 18.0 software.Results:Peripheral blood eosinophil count, percentage of peripheral blood eosinophil, total serum IgE level, and serum OVA-sIgE level in the STAT6 siRNA-treated group [(0.318±0.045)×10 3/μl, (3.667±0.479)%, (102.070±13.205) ng/ml, and (38.870±7.352) ng/ml] were significantly different from those of the Vehicle-treated group [(0.532±0.049)×10 3/μl, (6.710±1.061)%, (203.102±29.653) ng/ml, and (74.575±6.432) ng/ml, Z value was -2.56, -2.24, -2.40, and -2.56, respectively, all P<0.05] and Scramble siRNA-treated group [(0.493±0.036)×10 3/μl, (5.858±0.872)%, (189.964±30.042) ng/ml, and (80.935±8.358) ng/ml, Z value was -2.17, -2.08, -2.24, and -2.72, respectively, all P<0.05]. Besides, IL-5 and eotaxin-1 levels in the STAT6 siRNA-treated group [(312.279±34.281) pg/ml and (25.297±4.323) pg/ml] were significantly lower than those in the Vehicle-treated group [(689.667±31.905) pg/ml and (68.278±6.485) pg/ml, Z value was -2.73 and -2.88, respectively, both P<0.01] and Scramble siRNA-treated group [(661.783±42.094) pg/ml and (63.015±7.416) pg/ml, Z value was -2.72 and -2.81, respectively, both P<0.01]. Tissue eosinophil count in sinonasal mucosa was (29.132±4.163)/HPF in the STAT6 siRNA-treated group, and were significantly less than those in the Vehicle-treated group [(78.050±7.912)/HPF, Z=-2.88, P<0.01] and Scramble siRNA-treated group [(73.864±8.671)/HPF, Z=-2.72, P<0.01]. The expression level of STAT6 protein (0.105±0.021) was significantly decreased in the mice treated with STAT6 siRNA compared with PBS, Vehicle, and Scramble siRNA (0.232±0.037, 0.243±0.039, and 0.228±0.032, Z value was -2.25, -2.49, and -2.56, respectively, all P<0.05). Corresponding, p-STAT6 protein level (0.292±0.038) was markedly decreased by the introduction of STAT6 siRNA, the difference was statistically significant as compared with the Vehicle-and Scramble siRNA-treated groups (0.613±0.046 and 0.641±0.050, Z value was -2.81 and -2.88, respectively, both P<0.01). Immunofluorescence staining showed that p-STAT6 was mainly located in the nucleus of nasal epithelial cells and inflammatory cells. The green fluorescence of p-STAT6 expression in sinonasal mucosa in the STAT6 siRNA-treated group was weaker than that in the Vehicle-and Scramble siRNA-treated groups. Conclusion:Intranasal administration of STAT6 siRNA can significantly downregulate STAT6 expression, decrease p-STAT6 level, and prohibit the development of Th2-skewed ECRS.
