Hydrogen-rich gas enhances mitochondrial membrane potential and respiratory function recovery in Caco-2 cells post-ischemia-reperfusion injury

Background: Ischemia-reperfusion (I/R) injury induces oxidative stress, leading to damage in highly susceptible intestinal tissues. Molecular hydrogen (H2) has shown therapeutic potential in I/R injuries, with our prior research showing its efficacy in improving outcomes in rat intestinal transplantation models. However, its impact on mitochondrial function remain insufficiently understood. This study aims to elucidate how H2 modulates mitochondrial function impaired by I/R injury.
Methods: To assess the effects of H2 on I/R injury, cells were divided into three groups: a control group, a hypoxic group (99 % N2, 1 % O2, without H2 for 3, 6, or 24 h), and a hypoxic-H2 group (99 % H2, 1 % O2, for the same durations). After treatment, cells were reoxygenated under normoxic conditions (21 % O2) for 1, 2, 4, or 6 h. Mitochondrial membrane potential, oxygen consumption, and ATP production were measured. Reactive oxygen species production and apoptotic and metabolic regulators were also assessed.
Results: H2 markedly promoting mitochondrial recovery following I/R injury, by enhancing ATP production, restoring mitochondrial membrane potential, and improving oxygen consumption. It also reduced ROS levels and suppressed pro-apoptotic signaling. Notably, H2 suppressed the expression of HIF1α and PDK1, suggesting that H2 may act upstream of hypoxia-driven signaling pathways. These changes promoted oxidative phosphorylation and overall cellular function during reperfusion.
Conclusions: Our findings reveal that H2 therapy supports mitochondrial function, suppresses ROS, and modulates hypoxia-driven pathways in I/R injury. These insights advance the understanding of H2's potential in addressing I/R injury and provide a foundation for its application in other hypoxia-related conditions.