Description
Inhalation of toxic chemicals, including recent e-cigarettes, often cause life-threatening lung injury. Although exposure to polyhexamethylene guanidine (PHMG)-containing humidifier disinfectant (HD) has been identified as a cause of fatal lung injury, the mechanism underlying HD-associated lung injury (HDLI) is unknown. The present study evaluated global changes in gene expression in lung tissues from patients with PHMG-induced HDLI, and compared gene expression changes in PHMG-induced rat lung tissues. Significantly different expressions in lung tissues between patients with HDLI and unaffected controls were observed. Furthermore, several fibrosis-associated overlapping genes (such as MMP2 and COL1A2) shared between humans with HDLI and rats exposed to PHMG were identified. Interactome network analysis predicted different pathways between children and adults with HDLI: the TGFβ/SMAD signaling pathway was central in adults, whereas other pathways, including integrin signaling, were associated with HDLI in children. Further interactome network analysis revealed that Rap1 and CCKR signaling pathways were significantly enriched in HDLI compared with idiopathic pulmonary fibrosis as well as their recapitulation in the lung tissues of rats exposed to PHMG. Our results suggest that MMP2-mediated different mechanisms between children and adults may be associated with PHMG-induced HDLI development, and Rap1 and CCKR pathways appear to be crucial.