Ammonia induces autophagy via circ-IFNLR1/miR-2188-5p/RNF182 axis in tracheas of chickens.

Ammonia (NH3 ), an air pollutant in the living environment, has many toxic effects on various tissues and organs. However, the underlying mechanisms of NH3 -induced tracheal cell autophagy remains poorly understood. In present study, chickens and LMH cells were used as NH3 exposure models to investigate toxic effects. The change of tracheal tissues ultrastructure showed that NH3 exposure induced autolysosomes. The differential expression of 12 circularRNAs (circRNAs) was induced by NH3 exposure using circRNAs transcriptome analysis in broiler tracheas. We further found that circ-IFNLR1 was down-regulated, and miR-2188-5p was up-regulated in tracheal tissues under NH3 exposure. Bioinformatics analysis and dual luciferase reporter system showed that circ-IFNLR1 bound directly to miR-2188-5p and regulated each other, and miR-2188-5p regulated RNF182. Overexpression of miR-2188-5p caused autophagy and its inhibition partially reversed autophagy in LMH cells which were caused by ammonia stimulation or knockdown of circ-IFNLR1. The expressions of three autophagy-related genes (LC3, Beclin 1, and BNIP3) were observably up-regulated. Our results indicated that NH3 exposure caused autophagy through circ-IFNLR1/miR-2188-5p/RNF182. These results provided new insights for the study of ammonia on environmental toxicology on ceRNA and circRNAs in vivo and vitro.