Supersulphide airway protection in viral and chronic lung diseases

Supersulphides (inorganic and organic sulphides with sulphur catenation) manifest diverse physiological functions. These supersulphides are mainly generated from mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulphide synthase (CPERS). Here we found powerful protective functions of supersulphides in viral airway infections (influenza and COVID-19) and chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and aged lungs. Enhanced supersulphide exhalation also occurred from human airways in COVID-19 as well as the hamster model of SARS-CoV-2 infection, as identified by breath supersulphur-omics that we developed herein. The lung damage related to oxidative stress and inflammation in mouse models of COPD, IPF, and ageing and the lethal effects that resulted were mitigated by endogenous supersulphides, supplied via CARS2/CPERS or exogenously by the supersulphide donor glutathione trisulphide. Our findings thus elucidated the airway protective role of supersulphides and their therapeutic potential in viral and chronic lung diseases.