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

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 mu M, 100 mu M, 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. (C) 2010 Elsevier Inc. All rights reserved.