The Expression Of STING And Its Role In Chronic Rhinosinusitis

[BACKGROUND]Chronic rhino sinusitis(CRS) is a kind of inflammation, the prevalence in our China is about 9%, and shows an increasing trendency. Chronic sinusitis makes a great trouble in the quality of patients life, and becomes a social huge economic burden. CRS can be classified into Chronic rhinosinusitis with nasal polyps without NP(CRSs NP) and Chronic rhinosinusitis with nasal polyps( CRSw NP).Further, we divide CRSw NP into two categlories :EosCRSwNP and non EosCRSwNP,depending on the infilitration of eosinophlis. STING is an important intracellular molecule in ER(Endoplasmic reticulum),and is widely expressed in various types of cells such as epithelial cells, lymphocytes and mediate the production of type I interferon in innate immunity.In cancer,some studies have shown that STING is correlated with the progonosis,and can be used as a target for cancer therapy.Recently,some research even show that STING can suppress inflammation in autoimmune disease,such as SLE. The pathogenesis of CRS may involve in innate immunity, adaptive immunity and autoimmunity, the exact role of STING in the pathogenesis of CRS remains unknown.[OBJECTIVE]To investigate the expression and regulation of the innate immune molecules STING in CRSw NP, and to explore the relationship between the prognosis and STING. Specific research objectives are as follows:(1)To detect the expression level of STING and related genes in normal mucosa, EosCRSwNP and Non-EosCRSwNP;(2) To analyz of theexpression and localization of STING in the nasal mucosa and explore the regulation of STING;(3) To explore the involved signaling pathway as well as downstream molecules;(4) Analysis of the correlation between STING and peripheral blood eosinophil counts and patients symptoms[METHODS](1) Real-time RT-PCR is used to detect the expression of STING and related genes in normal mucosa, EosCRSwNP and Non EosCRSwNP(2) Immunohistochemistry and immunofluorescence to confirm STING expression and localization nasal mucosa(3) Cell culture is conducted to explore the local regulation of STING(4) Immunohistochemistry is conducted to search for the downstream molecules of STING(5) Statistic the severity of disease and analysis the correlation and STING.[RESULTS](1) RT-PCR reveal that compared with non EosCRSwNP and controls,the expression of STING is decreased in EosCRSwNP; the upstream of STING,c GAS is decreased in EosCRSwNP;The expression of IL5,IL13,IL25 is increased in EosCRSwNP compared with non EosCRSwNP and controls. And a strong negative correlation between STING and IL5,between STING and IL13 is found.(2) Immunohistochemistry shows that in normal control group, EosCRSwNP groups and Non-EosCRSwNP group, STING expresses both in epithelium and in stroma, the expression in epithelium takes a major proportion,which is proved by Immunofluorescence; The immunohistochemistry image analysis found STING a significant reduction in EosCRSwNP group than Non-EosCRSwNP group(P = 0.0009) and normal control group(P = 0.0003);(3) In vitro,by epithelial culture stimulated with the corresponding concentrations of the different cytokines,we found, TH2 type cytokines IL4, IL13 can inhibit the expression of STING,while IFN-γ, IL17 have the opposite function;(4) Collecting patients primary nasal epithelium, real-time quantitative PCR was conducted and found compared with non-EosCRSwNP group(P = 0.012) and normal control group(P = 0.001) the expression of STING was significantly decreased in the EosCRSwNP; In the three groups, c GAS has no significant difference; and inhibition of intracellular signal associated molecular SHP2 was significantly decreased in EosCRSwNP group than non-EosCRSwNP group(P = 0.003) and normal control group(P = 0.001); IL25 was increased significantly in the EosCRSwNP than non-EosCRSwNP group(P = 0.045) and normal control group(P = 0.0001) and angiogenesis-related cytokines VEGF was increased significantly in the EosCRSwNP than non-EosCRSwNP group(P = 0.0002) and normal control group(P = 0.006); Meanwhile,we find that, STING and SHP2 has a strong positive correlation(R = 0.5064, P = 0.0014) and STING and IL25 is a strong negative correlation(R =-0.6768, P = 0.0001);(5) Immunohistochemistry was conducted and found SHP2, VEGF and the related signaling pathways p-STAT3 STAT3 are expressed in epithelium.(6) Statistic the severity of the patient’s disease, we found that compared with Non-EosCRSwNP group and normal control group,EosCRSwNP group have higher facial pain scores, higher olfactory dysfunction scores and more nasal secretions; Compared with normal control group patients and Non-EosCRSwNP patients EosCRSwNP groups have higher scores of endoscopic and Lund-Mackay score; also we found three is negative correlation between the expression level of STING and peripheral eosinophil percentage(R =-0.454, P = 0.002); between the expression level of STING and Lund-Mackay score a negative correlation(R =-0.520, P = 0.001);and between the expression level of STING and endoscopic score(R =-0.494, P = 0.001).[CONCLUSION](1) This study found that there exists STING expression in nasal mucosa, especially in epithelial cells and compared with non-EosCRSwNP group and controls the expression level was significantly lower in EosCRSwNP group;(2) The present study demonstrated the local regulation of STING in epithelial cell and revealed the heterogeneity between EosCRSwNP group and Non-EosCRSwNP group;(3) In this study, the possible anti-inflammatory role of STING in nasal mucosa was implied, and further,through STAT3 and p-STAT3 signaling pathway was confirmed;(4) In the study of this issue we first found the localization and expression STING in the CRS, and analyz the relationship with eosinophils in peripheral blood and with the severity of the disease. STING may be an index for diseases prognosis, and may find a new way to treat EosCRSwNP.