© 2016 by the authors; licensee MDPI, Basel, Switzerland. Early myocardial reperfusion is an effective therapy but ischemia/reperfusion (I/R) causes lethal myocardial injury. The aging heart was reported to show greater cardiac damage after I/R injury than that observed in young hearts. Senescence marker protein 30 (SMP30), whose expression decreases with age, plays a role in reducing oxidative stress and apoptosis. However, the impact of SMP30 on myocardial I/R injury remains to be determined. In this study, the left anterior descending coronary artery was occluded for 30 min, followed by reperfusion in wild-type (WT) and SMP30 knockout (KO) mice. After I/R, cardiomyocyte apoptosis and the ratio of infarct area/area at risk were higher, left ventricular fractional shortening was lower, and reactive oxygen species (ROS) generation was enhanced in SMP30 KO mice. Moreover, the previously increased phosphorylation of GSK-3 β and Akt was lower in SMP30 KO mice than in WT mice. In cardiomyocytes, silencing of SMP30 expression attenuated Akt and GSK-3 β phosphorylation, and increased Bax to Bcl-2 ratio and cardiomyocyte apoptosis induced by hydrogen peroxide. These results suggested that SMP30 deficiency augments myocardial I/R injury through ROS generation and attenuation of Akt activation.
Kadowaki, S., Shishido, T., Sasaki, T., Sugai, T., Narumi, T., Honda, Y., … Kubota, I. (2016). Deficiency of senescence marker protein 30 exacerbates cardiac injury after ischemia/reperfusion. International Journal of Molecular Sciences, 17(4). https://doi.org/10.3390/ijms17040542