Ursodeoxycholic Acid Alleviates The Response Of Nasal Epithelial Cells To IL-13 Via TGR5 And Regulates The Pathogenesis Of Allergic Rhinitis

Objective:(1)To identify the bile acid profile in peripheral blood from patients with allergic rhinitis and control subjects;(2)To explore the effect of ursodeoxycholic acid on nasal epithelial cells and to investigate the regulatory mechanism of ursodeoxycholic acid in allergic rhinitis;(3)To confirm the role of ursodeoxycholic acid supplementation in Ovalbumin(OVA)-induced allergic murine model in vivo.Methods:The bile acid profiles including 26 bile acids in peripheral blood from patients with allergic rhinitis and control subjects were identified by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The expression and localization of bile acid receptors in human nasal mucosa were shown by immunohistochemical staining and immunofluorescence staining.Primary nasal epithelial cells(PNECs)were cultured in Air-liquid interface(ALI)system with or without Interleukin-13(IL-13)and ursodeoxycholic acid treatment and cell transfection were used to alter the expression of G protein-coupled bile acid receptor 1(TGR5)in nasal epithelial cells.After treatment,RNA was extracted from human nasal epithelial cells for real-time quantitative Polymerase Chain Reaction and RNA sequencing.Using ovalbumin and aluminum hydroxide adjuvant,an OVA-induced allergic animal model of was built and ursodeoxycholic acid was administered locally or systemically.Results:The bile acid profiles in peripheral blood of patients with allergic rhinitis differed from those in control subjects.And the levels of ursodeoxycholic acid in blood from allergic rhinitis patients were higher than control subjects,which was inversely correlated with the levels of serum total Immunoglobulin E(Ig E).Ursodeoxycholic acid treatment inhibited the response of PNECs upon IL-13 stimulation.Immunohistochemical staining and immunofluorescence staining showed abudance TGR5 expression on human nasal epithelial cells,other than Farnesoid X receptor(FXR)expression.Besides ursodeoxycholic acid,the TGR5 agonist or its downstream effector could reduce C-C motif chemokine ligand 26(CCL26)expression of PNECs induced by IL-13 stimulation,which was not regulated by the FXR agonist.After treatment with TGR5 receptor antagonist or Protein Kinase A blockage,the inhibitory effect of ursodeoxycholic acid on the response of PNECs upon IL-13 stimulation was reversed.Silencing TGR5 or TGR5 overexpression of PNECs modulated the inhibitory effect of ursodeoxycholic acid on the response of PNECs upon IL-13 stimulation.Compared to control mice,OVA-induced allergic mice showed more servere nasal symptoms,higer expression of inflammatory cytokines and chemokines as well as goblet cell hyperplasia.The supplementation of ursodeoxycholic acid(intragastric administration or intranasal instillation)could significantly relieve nasal symptoms,diminish the levels of inflammatory factors,eosinophil chemokines and mucin in the nasal mucosa,and alleviate goblet metaplasia of the nasal epithelium in allergic mice.Conclusions:(1)The levels of ursodeoxycholic acid in the peripheral blood of patients with allergic rhinitis was significantly increased,which was negatively correlated with the level of total Ig E in the peripheral blood of patients with allergic rhinitis;(2)Ursodeoxycholic acid treatment could inhibit the response of PNECs upon IL-13 stimulation.TGR5,one of main receptors of bile acids,was abudancly expressed on human nasal epithelial cells.And ursodeoxycholic acid modulated IL-13 induced cellular responses via the TGR5;(3)TGR5 was also expressed on mouse nasal mucosal epithelial cells.Locally or systemically ursodeoxycholic acid intervention inhibited nasal inflammation in OVAinduced allergic mice.