Protective effect of exogenous hydrogen sulfide on pulmonary artery endothelial cells by suppressing endoplasmic reticulum stress in a rat model of chronic obstructive pulmonary disease

Abstract Background Chronic obstructive pulmonary disease (COPD) is a multicomponent disorder characterized by inflammation, representing a significant leading cause of chronic morbidity and mortality. Reports have implicated hydrogen sulfide (H 2 S) in both the pathology and treatment of COPD. The present study aimed to explore the effects involved with exogenous H 2 S on endoplasmic reticulum stress (ERS) and pulmonary artery endothelial cells (PAECs) in a rat model of COPD. Methods Rat models of COPD were successfully established by means of passive smoke exposure and intratracheal injection with lipopolysaccharide (LPS). Pulmonary function tests were performed and histopathological changes were observed. The expression of ERS markers, glucose-regulated protein-78 (GRP78), and C/EBP homologous protein (CHOP) and caspase-12, associated with ERS-induced apoptosis, were determined by western blot and immunohistochemistry methods. TUNEL assay was applied to determine the apoptosis index (AI) in PAECs. Results Treatment with NaHS was followed by the exhibition of markedly increased forced expiratory volume over 0.3 s (FEV0.3)/forced vital capacity (FVC) and dynamic lung compliance as well as integral optical density (IOD), with decreased RI among COPD rats. Western blot analysis, immunohistochemistry and TUNEL assay results revealed there to be reduced expressions of GRP78, CHOP and caspase-12 in the lung tissues and AI of PAECs, post NaHS treatment. Conclusion The key findings of the current study highlight ERS in COPD rats, as well as well as reduced apoptosis in PAECs in connection with exogenous H 2 S by suppressing ERS.