A new class of glycomimetic drugs to prevent free fatty acid-induced endothelial dysfunction

Background: Carbohydrates play a major role in cell signaling in many biological processes. We have developed a set of glycomimetic drugs that mimic the structure of carbohydrates and represent a novel source of therapeutics for endothelial dysfunction, a key initiating factor in cardiovascular complications. Purpose: Our objective was to determine the protective effects of small molecule glycomimetics against free fatty acid­induced endothelial dysfunction, focusing on nitric oxide (NO) and oxidative stress pathways. Methods: Four glycomimetics were synthesized by the stepwise transformation of 2,5­dihydroxybenzoic acid to a range of 2,5­substituted benzoic acid derivatives, incorporating the key sulfate groups to mimic the interactions of heparan sulfate. Endothelial function was assessed using acetylcholine­induced, endotheliumdependent relaxation in mouse thoracic aortic rings using wire myography. Human umbilical vein endothelial cell (HUVEC) behavior was evaluated in the presence or absence of the free fatty acid, palmitate, with or without glycomimetics (1µM). DAF­2 and H2DCF­DA assays were used to determine nitric oxide (NO) and reactive oxygen species (ROS) production, respectively. Lipid peroxidation colorimetric and antioxidant enzyme activity assays were also carried out. RT­PCR and western blotting were utilized to measure Akt, eNOS, Nrf­2, NQO­1 and HO­1 expression. Results: Ex vivo endothelium­dependent relaxation was significantly improved by the glycomimetics under palmitate­induced oxidative stress. In vitro studies showed that the glycomimetics protected HUVECs against the palmitate­induced oxidative stress and enhanced NO production. We demonstrate that the protective effects of pre­incubation with glycomimetics occurred via upregulation of Akt/eNOS signaling, activation of the Nrf2/ARE pathway, and suppression of ROS­induced lipid peroxidation. Conclusion: We have developed a novel set of small molecule glycomimetics that protect against free fatty acidinduced endothelial dysfunction and thus, represent a new category of therapeutic drugs to target endothelial damage, the first line of defense against cardiovascular disease

Moderate Aortic Stenosis in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND The study investigators previously reported that moderate aortic stenosis (AS) is associated with a poor prognosis in patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF) (HFrEF). However, the respective contribution of moderate AS versus HFrEF to the outcomes of these patients is unknown.OBJECTIVES This study sought to determine the impact of moderate AS on outcomes in patients with HFrEF.METHODS The study included 262 patients with moderate AS (aortic valve area >1.0 and 2 and <4 m/s, at rest or after dobutamine stress echocardiography) and HFrEF (LVEF <50%). These patients were matched 1:1 for sex, age, estimated glomerular filtration rate, New York Heart Association functional class III to IV, presence of diabetes, LVEF, and body mass index with patients with HFrEF but no AS (i.e., peak aortic jet velocity <2 m/s). The endpoints were all-cause mortality and the composite of death and HF hospitalization.RESULTS A total of 262 patients with HFrEF and moderate AS were matched with 262 patients with HFrEF and no AS. Mean follow-up was 2.9 +/- 2.2 years. In the moderate AS group, mean aortic valve area was 1.2 +/- 0.2 cm(2), and mean gradient was 14.5 +/- 4.7 mm Hg. Moderate AS was associated with an increased risk of mortality (hazard ratio [HR]: 2.98; 95% confidence interval [CI]: 2.08 to 4.31; p < 0.0001) and of the composite of HF hospitalization and mortality (HR: 2.34; 95% CI: 1.72 to 3.21; p < 0.0001). In the moderate AS group, aortic valve replacement (AVR) performed in 44 patients at a median follow-up time of 10.9 +/- 16 months during follow-up was associated with improved survival (HR: 0.59; 95% CI: 0.35 to 0.98; p = 0.04). Notably, surgical AVR was not significantly associated with improved survival (p = 0.92), whereas transcatheter AVR was (HR: 0.43; 95% CI: 0.18 to 1.00; p = 0.05).CONCLUSIONS In this series of patients with HFrEF, moderate AS was associated with a marked incremental risk of mortality. AVR, and especially transcatheter AVR during follow-up, was associated with improved survival in patients with HFrEF and moderate AS. These findings provide support to the realization of a randomized trial to assess the effect of early transcatheter AVR in patients with HFrEF and moderate AS. (C) 2021 by the American College of Cardiology Foundation.Cardiolog