H2S preconditioning of human adipose tissue-derived stem cells increases their efficacy in an in vitro model of cell therapy for simulated ischemia

AIMS: A major limitation of cell-based therapies for ischemia-reperfusion injury is the excessive loss of administered cells. We investigated whether H2S can improve the survival and efficacy of therapeutic cells in an in vitro model of cell-based therapy for simulated ischemia.

MAIN METHODS: H9c2 rat cardiomyoblasts were exposed to oxygen-glucose deprivation and NaHS (3-30 μM) pretreated human adipose tissue derived stem cells (hASCs) were added after reoxygenization. Viability of both cell lines was assessed with flow cytometry after 24h. The effects of H2S on antioxidant defense, proliferation, AKT and ERK1/2 phosphorylation and mitochondrial activity were analyzed in hASCs. Proliferation was evaluated using propargylglycine, an inhibitor of endogenous H2S synthesis.

KEY FINDINGS: NaHS pretreatment decreased the ratio of necrotic therapeutic cells by 41.8% in case of 3 μM NaHS and by 34.3% with 30 μM NaHS. The ratio of necrotic postischemic cardiomyocytes decreased by 35%, but only with the use of 3 μM NaHS. Antioxidant defense mechanisms and ERK-phosphorylation were enhanced after 3 μM NaHS treatment while AKT-phosphorylation was suppressed. NaHS dose-dependently increased the proliferation of hASCs while pretreatment with propargylglycine decreased it.

SIGNIFICANCE: NaHS pretreatment can increase the survival of therapeutically used human adipose tissue-derived stem cells via increased antioxidant defense and improves the postischemic cardiac derived cells' survival as well. Proliferation of human adipose tissue-derived stem cells is enhanced by H2S. The underlying mechanisms involve enhanced ERK-phosphorylation and decreased AKT-phosphorylation. Pretreatment with NaHS may represent a simple pharmacological step that may enhance the efficacy of cell-based therapies.