A mitochondria-targeted H_(2)S-activatable fluorogenic probe for tracking hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury(HIRI)is the cause of postoperative hepatic dysfunction and failure,and even death.As an important biological effector molecule,hydrogen sulfide(H_(2)S)of mitochondria as a gasotransmitter that is usually used to protect against acute HIRI injury.However,the exact relationship between HIRI and mitochondrial H_(2)S remains tangled due to the lack of an effective analytical method.Herein,we have fabricated a mitochondria-targeted H_(2)S-activatable fluorogenic probe(Mito-GW)to explore the stability of mitochondrial H_(2)S and track the changes of mitochondrial H_(2)S during the HIRI.By virtue of pyridinium electropositivity and its amphiphilicity,Mito-GW could accumulate in mitochondria.It goes through an analyte-prompted immolation when reacts with H_(2)S,resulting in the releasing of the fluorophore(GW).Therefore,the extent of Mito-GW conversion to GW can be used to evaluate the changes of mitochondrial H_(2)S level in living cells and tissues.As proof-of-principle,we have used MitoGW to demonstrate the mitochondria H_(2)S-levels increase and then decrease during HIRI in vitro and in vivo.Our research highlights the tremendous potential of Mito-GW as a mitochondrial H_(2)S fluorogenic probe in elucidating the pathogenesis of HIRI,providing a powerful tool for promoting future research on hepatology.

Antioxidant properties of magnesium lithospermate B contribute to the cardioprotection against myocardial ischemia/reperfusion injury in vivo and in vitro

OBJECTIVE: To determine the cardioprotective effect of magnesium lithospermate B (MLB) on myocardial ischemia/reperfusion (MI/R) injury and to investigate the antioxidant potential in vivo and in vitro. METHODS: MI/R injury was induced by the occlusion of left anterior descending coronary artery for 30 min followed by reperfusion for 3 h in rats. After reperfusion, hearts were harvested to assess infarct size, histopathological damages, the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH) and malondialdehyde (MDA). Blood samples were col- lected to determine serum levels of creatine kinase-MB (CK-MB), cardiac troponin (cTnI) and lactate dehydrogenase (LDH). Furthermore, simulatedischemia/reperfusion (SI/R) injury in vitro was established by oxygen and glucose deprivation (OGD) for 2 h followed by 24-hour recovery period in cardiomyocytes. The activity of LDH in the cultured supernatant and the levels of intracellular reactive oxygen species (ROS), SOD and MDA in cardiomyocytes were also measured. Finally, cardiomyocytes apoptosis was determined with flow cytometry. RESULTS: MLB significantly limited infarct size, ameliorated histopathological damages and prevented leakage of CK-MB, cTnI and LDH. Additionally, SOD, CAT, GPx and GSH activities were notably increased by MLB, along with the MDA content decreased as compared with the model group in rats. In vitro study, MLB also decreased LDH activity in the cultured supernatant, increased SOD activity in cardiomyocytes, reduced intracellular ROS and MDA levels, and significantly suppressed cardiomyocytes apoptosis. CONCLUSION: MLB possessed remarkably cardioprotective effects on MI/R injury in vivo and in vitro. The protection of MLB may contribute to its antioxidant properties.