Protective effects of molecular hydrogen on lung injury from lung transplantation

Abstract

Lung grafts may experience multiple injuries during lung transplantation, such as warm ischaemia, cold ischaemia, and reperfusion injury. These injuries all contribute to primary graft dysfunction, which is a major cause of morbidity and mortality after lung transplanta- tion. As a potential selective antioxidant, hydrogen molecule (H2) protects against post- transplant complications in animal models of multiple organ transplantation. Herein, the authors review the current literature regarding the effects of H2 on lung injury from lung transplantation. The reviewed studies showed that H2 improved the outcomes of lung transplantation by decreasing oxidative stress and inflammation at the donor and recipient phases. H2 is primarily administered via inhalation, drinking hydrogen-rich water, hydrogen- rich saline injection, or a hydrogen-rich water bath. H2 favorably modulates signal trans- duction and gene expression, resulting in the suppression of pro-inflammatory cytokines and excess reactive oxygen species production. Although H2 appears to be a physiological regulatory molecule with antioxidant, anti-inflammatory and anti-apoptotic properties, its exact mechanisms of action remain elusive. Taken together, accumulating experimental evidence indicates that H2 can significantly alleviate transplantation-related lung injury, mainly via inhibition of inflammatory cytokine secretion and reduction in oxidative stress through several underlying mechanisms. Further animal experiments and preliminary human clinical trials will lay the foundation for the use of H2 as a treatment in the clinic.

Study details

Article type

Review

Disease / injury model

Lung transplantation

Outcome

Mixed

Findings

Taken together, accumulating evidence from animal studies suggests that the use of hydrogen can mitigate the injury of lung graft resulting from LTx and improve the lung graft function. Hydrogen exerts many biological effects, including anti-oxidative stress, anti-inflammation, anti-apoptosis on lung grafts by indirectly regulating signal transduction and gene expression, each of which involve multiple several cytoprotective signaling pathways and crosstalk.