Antithrombin III Alleviates Myocardial Ischemia/Reperfusion Injury by Inhibiting Excessive Autophagy in a Phosphoinositide 3-Kinase/Akt-Dependent Manner.

Autophagy is fundamental to myocardial ischemia/reperfusion (I/R) injury. Antithrombin III (AT) has been shown to protect cardiomyocytes against I/R injury; however, it is unknown whether it modulates autophagy. The objective of this study was to investigate whether AT regulates autophagy during I/R injury and, if so, to identify the potential mechanism involved. Our study showed that AT attenuated I/R injury in vivo and hypoxia/reoxygenation (H/R) injury in vitro. Autophagy was increased both in H9C2 cardiomyocytes during H/R injury and in mouse hearts following I/R injury. The stimulation of autophagy by rapamycin attenuated the protective effect of AT against H9C2 cell injury, indicating that autophagy is involved in the protective role of AT. Furthermore, the cardioprotective effects of AT were abolished by A6730, a specific Akt inhibitor. This study shows that AT exhibits cardioprotective effects by modulating autophagy during I/R injury in a phosphoinositide 3-kinase/Akt-dependent manner.

Effects of macrophage migration inhibitory factor on cardiac reperfusion injury in mice with depression induced by constant-darkness.

RATIONALE: Depression is associated with coronary artery disease and increases adverse outcomes and mortality in patients with acute myocardial infarction, but the underlying pathophysiological mechanisms remain unclear. OBJECTIVE: To evaluate the effect of macrophage migration inhibitory factor (MIF) on cardiac ischemia-reperfusion (I/R) injury in mice with constant darkness-induced depression. METHODS AND RESULTS: Twenty C57BL/6 mice (8 weeks old, male) were randomly divided into 2 groups: one group was housed in a 12h light/dark cycle environment (LD) and the other in a constant darkness environment (DD). After 3 weeks, constant darkness-exposed (DD) mice displayed depression-like behavior as indicated by increased immobility in the forced swim test (FST) and lower sucrose preference rate. Western blotting revealed cardiac MIF expression was significantly lower in the DD mice than that in the LD mice. Next, 84 mice were randomly divided into 4 groups: LD sham group, LD I/R group, DD sham group, and DD I/R group. Following ischemia and reperfusion, mice in the DD I/R group had a larger infarct area and lower heart function index than mice in the LD I/R group (P < 0.05 for both). The cardiac pAMPK and pACC expression levels of the DD I/R group were also lower in the DD I/R group (P < 0.05). CONCLUSION: DD-induced depression might cause decreased expression of MIF in the heart, resulting in downregulation of MIF-AMPK signaling and a subsequent adverse outcome after a cardiac I/R injury.

Macrophage migration inhibitory factor promoter polymorphisms (-794 CATT5-8): Relationship with soluble MIF levels in coronary atherosclerotic disease subjects.

BACKGROUND: We analyzed the relationship of -794 CATT5-8 MIF polymorphisms with soluble MIF in Coronary Atherosclerotic Disease (CAD) patients. METHODS: A total of 256 patients selected, on which 186 normal-coronary and 70 Coronary artery disease subjects, were recruited in the study (Retrospectively registered). Genotyping of -794 CATT5-8 polymorphisms were performed by PCR and DNA sequencing. Serum MIF levels were measured using an ELISA kit. Patients were classified by coronary angiogram, and CAD based on Gensini's integral degree (angiographic scoring system). RESULTS: The allele frequency and genotype frequency of -794 CATT5-8 did not show any differences in normal-coronary subjects and CAD subjects. In CAD patients, serum MIF levels was lower in CATT (5) subjects than in CATT (7) subjects, while the genotype of -794 CATT5-8 did not show differences in serum MIF levels. In addition, we found a decrease in serum MIF levels in carriers of the (5/5) genotypes the -794 CATT5-8 MIF polymorphisms, although it was not significant. There was no relationship of CAD class and the allele frequency of -794 CATT5-8. CONCLUSIONS: This study found no association between CAD class and -794 CATT5-8 MIF polymorphisms with soluble MIF levels in CAD Subjects. TRIAL REGISTRATION: NCT01750502 (November 2012, Retrospectively registered).

Amifostine Pretreatment Attenuates Myocardial Ischemia/Reperfusion Injury by Inhibiting Apoptosis and Oxidative Stress.

The present study was aimed at investigating the effect of amifostine on myocardial ischemia/reperfusion (I/R) injury of mice and H9c2 cells cultured with TBHP (tert-butyl hydroperoxide). The results showed that pretreatment with amifostine significantly attenuated cell apoptosis and death, accompanied by decreased reactive oxygen species (ROS) production and lower mitochondrial potential (ΔΨm). In vivo, amifostine pretreatment alleviated I/R injury and decreased myocardial apoptosis and infarct area, which was paralleled by increased superoxide dismutase (SOD) and reduced malondialdehyde (MDA) in myocardial tissues, increased Bcl2 expression, decreased Bax expression, lower cleaved caspase-3 level, fewer TUNEL positive cells, and fewer DHE-positive cells in heart. Our results indicate that amifostine pretreatment has a protective effect against myocardial I/R injury via scavenging ROS.