BACKGROUND: Defects in epithelial barrier have recently been associated with asthma and other allergies. The influence of laundry detergents on human bronchial epithelial cells (HBECs) and their barrier function remain unknown.OBJECTIVE: We investigated the effects of laundry detergents on cytotoxicity, barrier function, transcriptome and epigenome in HBECs.METHODS: Air-liquid interface cultures of primary HBECs from healthy control subjects, asthma and chronic obstructive pulmonary disease patients were exposed to laundry detergents and detergent residue after rinse. The cytotoxicity and epithelial barrier function were evaluated. RNA sequencing, assay for transposase accessible chromatin with high-throughput sequencing and DNA methylation arrays were used for checking transcriptome and epigenome.RESULTS: Laundry detergents and rinse residue showed dose dependent toxic effect to HBECs with irregular cell shape and leakage of lactate dehydrogenase after 24h exposure. A disrupted epithelial barrier function was found with decreased transepithelial electric resistance, increased paracellular flux and stratified tight junction immunostaining in HBECs exposed to laundry detergent at 1:25,000 dilutions or rinse residue at further 1:10 dilutions. RNA sequencing analysis showed that lipid metabolism, apoptosis progress and epithelial-derived alarmins related genes were up-regulated, while cell adhesion related genes were down-regulated by laundry detergent at 1:50,000 dilutions after 24h exposure without substantially affecting chromatin accessibility and DNA methylation.CONCLUSION: Our data demonstrate that laundry detergents even at a very high dilution and rinse residue show significant cell toxic and directly disruptive effects on the tight junction barrier integrity of HBECs without affecting the epigenome and tight junction genes expression.
View details for PubMedID 30500342