Hydrogen sulfide regulates cardiac mitochondrial biogenesis via the activation of AMPK.

Background: Hydrogen sulfide (HS) is an important regulator of mitochondrial bioenergetics, but its role in regulating mitochondrial biogenesis is not well understood. Using both genetic and pharmacological approaches, we sought to determine if HS levels directly influenced cardiac mitochondrial content.

Results: Mice deficient in the HS-producing enzyme, cystathionine γ-lyase (CSE KO) displayed diminished cardiac mitochondrial content when compared to wild-type hearts. In contrast, mice overexpressing CSE (CSE Tg) and mice supplemented with the orally active HS-releasing prodrug, SG-1002, displayed enhanced cardiac mitochondrial content. Additional analysis revealed that cardiac HS levels influenced the nuclear localization and transcriptional activity of peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) with higher levels having a positive influence and lower levels having a negative influence. Studies aimed at evaluating the underlying mechanisms found that HS required AMP-activated protein kinase (AMPK) to induce PGC1α signaling and mitochondrial biogenesis. Finally, we found that restoring HS levels with SG-1002 in the setting of heart failure increased cardiac mitochondrial content, improved mitochondrial respiration, improved ATP production efficiency, and improved cardiac function.

Conclusions: Together, these results suggest that hydrogen sulfide is an important regulator of cardiac mitochondrial content and establishes that exogenous hydrogen sulfide can induce mitochondrial biogenesis via an AMPK-PGC1α signaling cascade.