Glyceryl trinitrate (GTN), also known as nitroglycerin, has been used to treat angina and heart failure for more than 130 years. Recently, it was shown that mitochondrial aldehyde dehydrogenase-2 (ALDH2) is responsible for formation of NO, the metabolite needed for GTN efficacy. In the present study, we show that the common G-to-A polymorphism in exon 12 of ALDH2 — resulting in a Glu504Lys replacement that virtually eliminates ALDH2 activity in both heterozygotes and homozygotes — is associated with a lack of efficacy of sublingual GTN in Chinese subjects. We also show that the catalytic efficiency (V_max/K_m) of GTN metabolism of the Glu504 protein is approximately 10-fold higher than that of the Lys504 enzyme. We conclude that the presence of the Lys504 allele contributes in large part to the lack of an efficacious clinical response to nitroglycerin; we recommend that this genetic factor be considered when administering nitroglycerin to patients, especially Asians, 30–50% of whom possess the inactive ALDH2*2 mutant allele.

Cardiac fibrosis has been known to play an important role in the etiology of heart failure following myocardial infarction (MI). B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a transcriptional repressor, is important for fibrogenesis in the kidneys. However, the effect of BMI1 on ischemia-induced cardiac fibrosis remains unclear. BMI1 was strongly expressed in the infarct region one week post-MI in mice and was detected by Western blot and histological analysis. Lentivirus-mediated overexpression of BMI1 significantly promoted cardiac fibrosis, worsened cardiac function 4 weeks after the intervention in vivo, and enhanced the proliferation and migration capabilities of fibroblasts in vitro, while the downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in mice 4 weeks post-MI in vivo. Furthermore, up-regulated BMI1 inhibited PTEN expression, enhanced PI3K expression, and increased the phosphorylation level of AKT and mTOR in mice 4 weeks after lentiviral infection, which was in accordance with the changes seen in their infarcted myocardial tissues. At the same time, the effects of BMI1 on cardiac fibroblasts were reversed in vitro when these cells were exposed to NVP-BEZ235, a dual kinase (PI3K/mTOR) inhibitor. In conclusion, BMI1 is associated with cardiac fibrosis and dysfunction following MI by regulating cardiac fibroblast proliferation and migration, and these effects could be partially explained by the regulation of the PTEN-PI3K/AKT-mTOR pathway.

This cross-sectional study tested the hypothesis that decreased serum levels of tetranectin (TN), a regulator of the fibrinolysis and proteolytic system, is associated with the presence and severity of CAD. We conducted a systematic serological and immunohistochemical (IHC) analysis to respectively compare the TN levels in serum and artery samples in CAD patients and healthy controls. Our results showed that serum levels of TN were significantly lower in patients with CAD than in healthy controls. Further analysis via trend tests revealed that serum TN levels correlated with the number of diseased arteries. Besides, the multivariate logistic regression model revealed TN as an independent factor associated with the presence of CAD. Additionally, IHC analysis showed that TN expression was significantly higher in atherosclerotic arteries as compared to healthy control tissues. In conclusion, our study suggests that increased serum TN level is associated with the presence and severity of diseased coronary arteries in patients with stable CAD.

Background: Adverse cardiac remodeling after ST-segment elevation myocardial infarction (STEMI) is a major cause for poor cardiovascular outcomes such as heart failure. The predisposing factors and underlying mechanisms remain not fully understood. This study investigates the association of insulin resistance and dysglycemia with left ventricular (LV) remodeling after STEMI in non-diabetic patients. Methods: A total of 485 non-diabetic subjects with STEMI who underwent primary percutaneous coronary intervention were consecutively enrolled and followed up for 12 months. Relation of homeostasis model assessment-estimated insulin resistance (HOMA-IR) and glucose levels to changes in echocardiography parameters was studied. Results: Left ventricular dilation was detected in 49.1% of subjects at 12-month follow-up after STEMI, and was more severe in subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and high HOMA-IR levels. HOMA-IR remained correlated to changes in LV dimensions after adjusting for confounding risk factors. Multivariate regression analysis demonstrated that higher HOMA-IR was independently associated with greater LV dilation after STEMI. A significant interaction term was present between HOMA-IR and IGT in the model (P = 0.001). Conclusions: Our study reveals that insulin resistance and dysglycemia are prevalent in non-diabetic patients with STEMI and are predictors of the post-infarction LV dilation. Trial registration Trials number, NCT02089360; registered on March 17, 2014