Hydrogen Sulfide Protects Against Ischemia-Reperfusion Injury in an In Vitro Model of Cutaneous Tissue Transplantation¹

Background

Ischemia-reperfusion injury (IRI) is a source of morbidity and mortality in many clinical scenarios, and has as one of its many consequences the induction of cellular apoptosis. Hydrogen sulfide (H₂S) may decrease cellular metabolism in a reversible, nontoxic manner. An in vitro model of cutaneous tissue transplantation was developed to assess whether H₂S could ameliorate cellular injury caused by IRI.

Methods

Human umbilical vein endothelial cells (HUVECs) were treated with media containing NaHS (0, 10 μM, 100 μM, or 1 mM) and exposed to normoxia (21% oxygen), hypoxia (1%), or anoxia (0%). Cells were then returned to normoxia, and apoptosis was quantified using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Fibroblasts (3T3s) were treated with H₂S and exposed to anoxia in a similar fashion.

Results

Treatment with H₂S resulted in a significant decrease in apoptosis in HUVECs and 3T3s subjected to IRI. Toxicity of H₂S was not observed, although the protective effect was less evident at higher doses.

Conclusion

This is the first study to examine H₂S and the cellular components of cutaneous flaps in the setting of IRI. Our results demonstrate that H₂S significantly decreases apoptosis in vitro in the setting of IRI. These data suggest H₂S may mitigate IRI in vivo, and, therefore, has potential as a therapy for improving tissue survivability in clinical scenarios.

Key Words: hydrogen sulfide, ischemia-reperfusion injury, human umbilical vein endothelial cells, tissue transplantation