the cytokinedriven regulation of secretoglobins in normal human upper airway and their expression particularly that of uteroglobinrelated protein 1 in chronic rhinosinusitis background the involvement of secretoglobins scgbs other than scgb1a1 clara cell 10kda protein cc10 in human airway diseases remains unexplored among those scgbs scgb3a2 uteroglobinrelated protein 1 ugrp1 is particularly interesting given its structure and function similarities with scgb1a1 cc10 the aim of this study was to investigate the expression regulation of scgbs other than scgb1a1 cc10 in human upper airway and their potential involvement particularly that of scgb3a2 ugrp1 in chronic rhinosinusitis crs with nasal polyps crswnp and without nasal polyps crssnpmethods eight scgb family members including scgb3a2 ugrp1 scgb1c1 ligand binding protein ryd5 scgb1d1 lipophilin a scgb1d2 lipophilin b scgb1d4 interferon inducible scgb scgb2a1 mammaglobin 2 scgb2a2 mammaglobin 1 and scgb3a1 uteroglobinrelated protein 2 were studied the regulation of scgbs mrna expression in normal nasal mucosa by proinflammatory th1 and th2 cytokines was studied through nasal explant culture scgbs mrna expression levels in crssnp and crswnp patients and controls were compared the mrna levels were detected by means of quantitative reverse transcriptasepolymerase chain reaction the protein expression of scgb3a2 ugrp1 was analyzed using immunohistochemistryresults the expression of scgbs except scgb1d2 lipophilin b could be found in upper airway and be differentially regulated by different cytokines scgb3a2 ugrp1 mrna expression was induced by th1 cytokine but suppressed by proinflammatory and th2 cytokines scgbs mrna expression was altered in crs particularly scgb3a2 ugrp1 protein and mrna expression was markedly decreased in both crssnp and crswnp and its protein levels inversely correlated with the number of total infiltrating cells preoperative sinonasal ct scores and postoperative endoscopy and symptom scoresconclusion scgbs except scgb1d2 lipophilin b are expressed in human upper airway and their expression can be differentially regulated by inflammatory cytokines scgbs mrna expression is altered in crs reduced production of ugrp1 which is likely due at least in part to a local cytokine environment may contribute to the hyperinflammation in crs and correlates with response to surgery