Atrial fibrillation and its complications in arterial hypertension: The potential preventive role of ω-3 polyunsaturated fatty acids

Persistent hypertension induces atrial remodeling and atrial fibrillation through DNA damage and ATM/CHK2/p53 signaling pathway

Atrial fibrillation (AF) is the most prevalent arrhythmia in clinical practice, with hypertension emerging as an independent risk factor. Previous literature has established associations between DNA damage response (DDR) and autophagy in relation to the pathogenesis of AF. The aim of this study was to evaluate the effect of atrial DNA damage response in persistent hypertension-induced atrial electrical and structural remodeling, and to further explore the potential therapeutic targets. Patient samples, spontaneous hypertensive rats (SHR) and angiotensin II (Ang II)-challenged HL-1 cells were employed to elucidate the detailed mechanisms. Bioinformatics analysis and investigation on human atrial samples revealed a critical role of DDR in the pathogenesis of AF. The markers of atrial DNA damage, DDR, autophagy, inflammation and fibrosis were detected by western blot, immunofluorescence, monodansyl cadaverine (MDC) assay and transmission electron microscopy. Compared with the control group, SHR exhibited significant atrial electrical and structural remodeling, abnormal increase of autophagy, inflammation, and fibrosis, which was accompanied by excessive activation of DDR mediated by the ATM/CHK2/p53 pathway. These detrimental changes were validated by in vitro experiments. Ang II-challenged HL-1 cells also exhibited significantly elevated γH2AX expression, and markers related to autophagy, inflammation as well as structural remodeling. Additionally, inhibition of ATM with KU55933 (a specific ATM inhibitor) significantly reversed these effects. Collectively, these data demonstrate that DNA damage and the subsequently overactivated ATM/CHK2/p53 pathway play critical roles in hypertension-induced atrial remodeling and the susceptibility to AF. Targeting ATM/CHK2/p53 signaling may serve as a potential therapeutic strategy against AF.

Comparative analysis of lipid components in fresh Crassostrea Hongkongensis (raw) and its dried products by using high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF-MS)

The lipids of the oyster (Crassostrea hongkongensis) have a special physiological activity function, which is essential to maintain human health. However, comprehensive research on their lipids species and metabolism is not so common. In our study, based on the high-performance liquid chromatography/quadrupole time-of-flight mass spectrometer (HPLC/Q-TOF-MS), the non-targeted lipidomics research of Crassostrea hongkongensis fresh and dried products was determined. Meanwhile, we analyzed its lipid outline, screened the differences between the lipid molecules of Crassostrea hongkongensis fresh and dried products, and determined the lipid metabolic pathway. Results showed that 1,523 lipid molecules were detected, in which polyunsaturated fatty acids mostly existed in such lipids as phosphoglyceride. Through the multivariate statistical analysis, according to the conditions of P < 0.05, FC > 2 or FC < 0.05, and VIP > 1.2, 239 different lipid molecules were selected, including 37 fatty acids (FA), 60 glycerol phospholipids (GP), 20 glycerin (GL), 38 sheath lipids (SP), 31 steroid lipids (ST), 36 polyethylene (PK), and 17 progesterone lipids (PR). Combined with the Kyoto Encyclopedia of Genes and Genomes (KEGG), the differential lipid molecules were analyzed to mainly determine the role of the glycerin phospholipid metabolic pathway. As a whole, the results of this study provide the theoretical basis for the high-value utilization of oysters and are helpful to the development of oysters' physiological activity functions and deep utilization.

Mechanisms Underlying Antiarrhythmic Properties of Cardioprotective Agents Impacting Inflammation and Oxidative Stress

The prevention of cardiac life-threatening ventricular fibrillation and stroke-provoking atrial fibrillation remains a serious global clinical issue, with ongoing need for novel approaches. Numerous experimental and clinical studies suggest that oxidative stress and inflammation are deleterious to cardiovascular health, and can increase heart susceptibility to arrhythmias. It is quite interesting, however, that various cardio-protective compounds with antiarrhythmic properties are potent anti-oxidative and anti-inflammatory agents. These most likely target the pro-arrhythmia primary mechanisms. This review and literature-based analysis presents a realistic view of antiarrhythmic efficacy and the molecular mechanisms of current pharmaceuticals in clinical use. These include the sodium-glucose cotransporter-2 inhibitors used in diabetes treatment, statins in dyslipidemia and naturally protective omega-3 fatty acids. This approach supports the hypothesis that prevention or attenuation of oxidative and inflammatory stress can abolish pro-arrhythmic factors and the development of an arrhythmia substrate. This could prove a powerful tool of reducing cardiac arrhythmia burden.

Relationship between serum angiopoietin-like 4 levels and recurrence of atrial fibrillation

Objective

To investigate the association between serum angiopoietin-like 4 (ANGPTL4) levels and recurrence of atrial fibrillation (AF) after catheter ablation.

Methods

This retrospective study recruited patients with AF undergoing catheter ablation and they were divided into two groups (new-onset AF group and recurrent AF group). Demographic, clinical, and laboratory parameters were collected.

Results

A total of 192 patients with AF were included, including 69 patients with recurrence of AF. Serum ANGPTL4 levels were lower in patients with recurrent AF than in those with new-onset AF. Serum ANGPTL4 levels were positively correlated with superoxide dismutase and peroxisome proliferator-activated receptor γ, and negatively correlated with the CHA2DS2-VASC score, left atrial diameter, and levels of brain natriuretic peptide, malondialdehyde, high-sensitivity C-reactive protein, and interleukin-6. The receiver operating characteristic curve showed that the best cut-off for recurrent AF was serum ANGPTL4 levels  < 19.735 ng/mL, with a sensitivity and specificity of 63.9% and 74.5%, respectively. Serum ANGPTL4 levels were significantly associated with recurrence and new onset of AF (odds ratio, 2.241; 95% confidence interval, 1.081–4.648).

Conclusions

Serum ANGPTL4 levels are lower in patients with recurrent AF than in those with new-onset AF, and are associated with cardiac hypertrophy, oxidative stress, and inflammation.

Optimal Dose of n-3 Polyunsaturated Fatty Acids for Cardiovascular Event Prevention

Background: The n-3 polyunsaturated fatty acids (PUFA), represented by eicosapentaenoic acid (EPA) and docosahexaenoic acid, have anti-atherogenic effects (e.g., neutral fat-lowering effects) and other beneficial effects such as antiplatelet, anti-inflammatory, plaque stabilizing, vascular endothelial function ameliorative, antihypertensive, and anti-arrhythmic effects. Epidemiological studies and clinical trials have assessed the inhibitory effects of n-3 PUFA on cardiovascular events. Methods and Results: Studies that reported positive outcomes, such as the Japan EPA Lipid intervention Study (JELIS) and the Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia (REDUCE-IT), noted a tendency toward the use of high-dose n-3 PUFA (1.8-4 g/day). The Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-Prevenzione (GISSI-Prevenzione) trial and the JELIS had high EPA/arachidonic acid (AA) baseline ratios. In contrast, negative outcome studies, such as the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial, Risk and Prevention study, A Study of Cardiovascular Events in Diabetes (ASCEND), and the Vitamin D and Omega-3 Trial (VITAL) had participants who tended to use low-dose n-3 PUFA (0.84-1 g/day) and to have low baseline EPA/AA. Conclusions: Differences in baseline EPA/AA ratio and the EPA/AA ratio threshold for the prevention of cardiovascular events seem to contribute to the different outcomes, together with the dose of n-3 PUFA.