Expression And Regulation Of Th9 Cell And Epithelial Cell 15-lipoxygenase 1 In Chronic Rhinosinusitis And Nasal Polyps

Objective: IL-9-producing T helper cells and mi RNAs have recently been shown to contribute to the pathogenesis of allergic diseases.However,it remains unknown whether mi RNAs regulate Th9 polarization in patients with chronic rhinosinusitis and nasal polyps(CRSw NP).To evaluated Th9 inflammation in nasal tissues from CRSw NP subjects and health controls(HCs)and determine whether mi RNAs regulated Th9 differenciationthrough transcription factor IRF4 in vitro.Methods: Transcription factors PU-1 and IRF4,cytokines IL-9 and IL-10,and CD4+PU-1+IL-9+Th9 cells wereevaluated from nasal polyp and turbinate tissues by flow cytometry,Western blot,RT-PCR,and immunofluorescence.In vitro Th9 cells were cultured and transfected by mi RNA mimics and inhibitors.Transcription factors and cytokines were analyzed by western blot and RT-PCR.Results: The levels of the Th9 transcription factors PU-1 and IRF4,and cytokine IL-9,were elevated in nasal polyp tissues;the increases correlated significantly with tryptase levels.Inhibition of mi RNA-27 b synthesis increased IRF4 expression in Th9 cells and induced IL-9 production.The addition of exogenous mi RNA-27 b mimic reduced IRF4 expression in Th9 cells.Conclusions: The data suggest that patients with CRS and nasal polyps have high levels of Th9 cells that may be associated with mast cell accumulation.Evaluation of mi RNA-27 b actions may identify new targets for control of Th9 cell-mediated inflammation in patients with nasal polyps.Objective:15-lipoxygenase 1(15LO1)is expressed in airway epithelial cells in Type 2(T2)-Hi asthma,in association with eosinophilia.Chronic rhinosinusitis with nasal polyps(CRSw NP)is also associated with T2 inflammation and eosinophilia.Eotaxin-3/CCL26 has been reported to be regulated by 15LO1 in lower airway epithelial cells.However,its relation to 15LO1 in CRSw NP or mechanisms for its activation are unclear.To evaluate 15LO1 and CCL26 in nasal epithelial cells(NECs)from CRSw NP subjects and health controls(HCs)and determine whether 15LO1 regulates CCL26 in NECs via ERK activation.Methods: 15LO1,CCL26,and phospho-ERK were evaluated from CRSw NP and HCs NECs and tissues.15LO1/CCL26 and CCL26/Cytokeratin5 were co-localized by immunofluorescence.IL-13 stimulated NECs were cultured at an air-liquid interface with or without ALOX15 Dsi RNA transfection,a specific 15LO1 enzymatic inhibitor and two ERK inhibitors.15LO1 and CCL26 m RNA and protein were analyzed by q PCR,Western blot,ELISA.Results: 15LO1 was increased in NP compared to middle turbinate(MT)NECs from CRSw NP subjects and HC.15LO1 correlated with CCL26 expression and co-localized with CCL26 in basal cells of MT and NP.In primary NECs in vitro,15LO1 knockdown and inhibition decreased IL-13-induced ERK phosphorylation and CCL26 expression.ERK inhibition(alone)similarly decreased IL-13-induced CCL26.Phospho-ERK was increased in NECs from CRSw NP and positively correlated with both 15LO1 and CCL26.Conclusions: 15LO1 is increased NP NECs and contributes to CCL26 expression through ERK activation.15LO1 should be considered a novel therapeutic target for CRSw NP.