Clinical implications of plasma Nogo-A levels in patients with coronary heart disease

Nogo-A Mediated Endoplasmic Reticulum Stress During Myocardial Ischemic-Reperfusion Injury in Diabetic Rats

Among the three isoforms encoded by neurite outgrowth inhibitor proteins has been intensely investigated as a central nervous system inhibitor. Although neurite outgrowth inhibitor protein-A (Nogo-A) expression is increased in plasma of patients who have experienced a coronary heart disease, its role in heart disease is not well elucidated. In this study, we discovered a significant increase in Nogo-A expression in diabetic myocardial ischemia reperfusion (MI/R) injury conditions. Accelerated Nogo-A and MI/R injury in diabetic rats was attenuated by tauroursodeoxycholic acid treatment and knockdown of Nogo-A per se is sufficient to decrease endoplasmic reticulum (ER) stress as well as prevents cardiomyocyte apoptosis. We hypothesized that decreased Nogo-A levels might reducing diabetic MI/R injury. Nogo-A interacted with C/EBP homologous protein, suggesting a role for Nogo-A in ER stress during diabetic MI/R. In conclusion, Nogo-A mediated ER stress plays a major role in diabetic MI/R injury, and pathologically altered Nogo-A expression mediates diabetic MI/R injury, suggesting Nogo-A as a novel target for the treatment of diabetic MI/R injury in clinical settings.

Renin-angiotensin system inhibitor attenuates oxidative stress induced human coronary artery endothelial cell dysfunction via the PI3K/AKT/mTOR pathway

INTRODUCTION

The renin-angiotensin system is associated with blood pressure regulation, inflammation, oxidative stress and insulin resistance. It can decrease intracellular oxidative stress. Stimulation with H₂O₂ leads to increased oxidative stress and activation of the AKT/mTOR pathway. However, the role of renin-angiotensin system inhibitors in oxidative stress-induced endothelial cell dysfunction and H₂O₂-induced AKT activation remains unclear.

MATERIAL AND METHODS

Human coronary artery endothelial cells (HCAECs) were used. The cells were treated with H₂O₂, captopril, the AKT inhibitor MK-2206, and the AKT activator SC79, either separately, or in combination. p53 and ICAM-1 expression, and p-eNOS, p-Akt and mTOR activation were measured by Western blot. Cell viability was assessed by MTT assay. Levels of reactive oxygen species (ROS) were assayed by flow cytometry. Proliferation was monitored by BrdU labeling, while cell migration and invasion were determined by wound healing and Transwell assays, respectively.

RESULTS

The renin-angiotensin system inhibitor captopril reversed H₂O₂-induced oxidative stress and apoptosis in HCAECs. Co-treatment with captopril and the AKT inhibitor MK-2206 reduced the H₂O₂-induced P53 and ICAM-1 protein expression (p < 0.05). The proliferation, migration and invasion of HCAECs were significantly enhanced by co-treatment with captopril and MK-2206 (p < 0.05).

CONCLUSIONS

The study revealed the protective effect of captopril against H₂O₂-induced endothelial cell dysfunction through the AKT/mTOR pathway, and its enhancement of cell survival. These findings provide new insights into the protective effects of captopril and novel therapeutic approaches to treatment of cardiovascular disease.

Soluble urokinase plasminogen activator receptor in one-year prediction of major adverse cardiac events in patients after first myocardial infarction treated with primary percutaneous coronary intervention

INTRODUCTION

Soluble urokinase plasminogen activator receptor (suPAR) level reflects the general condition of the organism and was proved to give independent information in risk stratification of patients. The aim of this study was to assess the usefulness of suPAR in the prediction of adverse cardiac events in patients with first myocardial infarction (MI) undergoing primary percutaneous coronary intervention. Additionally, the diagnostic power of suPAR was assessed.

MATERIAL AND METHODS

One hundred and thirty-nine of 150 consecutive patients were included in the study. Serum suPAR level (ELISA, Virogates) as well as C-reactive protein (on admission and at discharge) and maximum troponin T (assessed from successive 6-hour periods of blood collection) were measured. In the 1-year follow-up study the following major adverse cardiac events were observed: myocardial infarction, revascularization, stroke and death.

RESULTS

Multi-variable analysis revealed prognostic usefulness only for suPAR and glomerular filtration rate: p < 0.0001 and p = 0.018; OR = 2.59 and OR = 0.98 respectively, with area under the curve in receiver operating characteristic analysis for both parameters simultaneously 0.89 (p < 0.0001). There was no correlation between suPAR level and the left ventricular dysfunction parameters or the MI type.

CONCLUSIONS

Soluble urokinase plasminogen activator receptor level appears to be an independent useful biomarker for the prediction of major adverse cardiac events early after first myocardial infarction. The biomarker's level seems to have more prognostic than diagnostic power.