Hydrogen Regulates The HIF-1? Level In Lung Tissue Of Septic Mice

Objective:Sepsis is considered to be the life-threatening multiple organ dysfunction that is triggered by the microbial infection in clinical practice.Patients with sepsis often develop acute lung injury.It causes physical and psychological burden on patients.And the methods for treatment are limited and lack of specificity.The previous study had demonstrated the protective effect of a low concentration?2%?of H₂ for treatment to acute lung injury associated with sepsis.But the concrete mechamism of this protective effect by use H₂ for treatment still remains unclear.This study aim to investigate the effect of low concentration H₂ inhalation on HIF-1?expression in lung tissue of septic mice,to explore the molecular mechanism of H₂treatment on ALI in septic mice,which might lay scientific foundation for developing the new strategy can be used in treatment of sepsis.Methods:6 weeks old male ICR mice,weighed 20-25 g,were randomly divided as follows four groups:sham operation,sham operation+H₂,sepsis and sepsis+H₂.Cecal ligation and puncture?CLP?operation was performed on mice to induce sepsis.The mice in SO+H₂ group and S+H₂ group were given H₂ inhalation treatment for 1 hour at the 1^st h and 6^th h after the operation.The 7-day survival rate of mice in four groups was observed.Mice were executed under anesthesia and lung tissue were harvested at24th h after the operation.ITRAQ quantitative proteomics method for proteomic analysis of lung tissue and screening the differences betwwen each proteome produced by the H₂ inhalation,then advanced bioinformatics analysis to eaxmine the enrichment of these differential proteins in HIF-1 signaling pathway.The expression levels of HIF-1?and SEMA 7A were detected by Westen Blot method.Results:Low concentration of hydrogen inhalation treatment significantly improved the 7-day survival rate?p<0.05?in septic mice,and improved the general condition of mice.23 significant differential proteins were detected and involved in 11 pathways by analysis of lung tissue proteome in the four grops mice.P-value for significant enrichment of HIF-1 signaling pathway was p=0.009?<0.05?,indicate that significant differential proteins were enriched in this pathway.24 hours after the operation,expression level of the HIF-1?and SEMA 7A in lung tissue of mice in SO and SO+H₂ group has no significant difference?P>0.05?,expression level of HIF-1?and SEMA 7A of mice in S group has a significant rise than that of SO group?P<0.05?,expression level of HIF-1?and SEMA 7A of mice in S+H₂ group decreased significantly than that of S group?P<0.05?.Conclusion:A low concentration of H₂ treatment in the 1st h and 6th h after the operation can improve the survival rate of septic mice,and improve the general condition of mice.Significant differential proteins result from the treatment of hydrogen inhalation are enriched in the HIF-1 signaling pathway,demonstrating its participation in the mechanism of lung protective effect of H₂ therapy for sepsis.Sepsis induced stabilization of HIF-1?and enhance the expression level in lung tissue,the change trend significantly weaken with H₂ traetmen.It indicate that HIF-1?may involved in the mechanism of lung protection of hydrogen therapy.H₂ therapy can reduce the expression level change of SEMA 7A in lung tissue induced by sepsis,indicating that SEMA7A also may play a role in the mechanism of lung protection.HIF-1?and its signaling pathway may be involved in the mechanism of lung protection during the H₂ treatment for acute lung injury associated with sepsis,and SEMA 7A may be a therapeutic target in the future.