The Influence of Eicosapentaenoic Acid to Arachidonic Acid Ratio on Long-term Cardiovascular Events Following Percutaneous Coronary Intervention

Lysophosphatidylcholine, rich in n-3 polyunsaturated fatty acids, inhibits leukotriene production by mouse mast cells

In fishery industries, large amounts of byproducts are discarded during processing; therefore, their use as a source of n-3 polyunsaturated fatty acids (PUFAs) is beneficial. In this study, we evaluated the potential anti-allergic effect of lysophosphatidylcholine (Lyso-PtdCho) derived from squid skin phosphatidylcholine (PtdCho) by measuring the production of leukotriene (LT) B4 and C4, which are chemical mediators produced by mast cells in immediate allergic reactions. Squid Lyso-PtdCho, with docosahexaenoic acid exclusively esterified at the sn-2 position, significantly inhibited LT production, whereas the original PtdCho obtained from squid skin showed no inhibitory activity. Lyso-PtdCho prepared from starfish viscera PtdCho, which exclusively binds eicosapentaenoic acid at the sn-2 position, also inhibited LT production, although the effect was moderate compared with that of the squid Lyso-PtdCho. It has been suggested that Lyso-PtdCho containing n-3 PUFA may alleviate allergic symptoms and contribute to the effective utilization of fishery wastes and processing byproducts.

Arachidonic acid is involved in high-salt diet-induced coronary remodeling through stimulation of the IRE1α/XBP1s/RUNX2/OPN signaling cascade

BACKGROUND

The impact of a high-salt (HS) diet on metabolic disturbances in individuals with coronary heart disease remains unclear. The arachidonic acid (AA) metabolic pathway is closely linked to the development of cardiometabolic diseases and atherosclerotic cardiovascular diseases. Furthermore, endoplasmic reticulum stress (ERS) has emerged as a major contributor to cardiometabolic diseases. AA-related inflammation and ERS are hypothesized to play a role in HS diet-induced coronary remodeling.

METHODS

Rats were subjected to an HS diet for 4 weeks, and the serum concentration of AA was measured via enzyme-linked immunosorbent assay. Immunofluorescence staining and vascular tension measurements were conducted on coronary arteries. In addition, AA-stimulated coronary artery smooth muscle cells (CASMCs) were treated with ERS inhibitors to explore the underlying pathway involved.

RESULTS

Increased susceptibility to myocardial infarction in the HS diet-fed rats was accompanied by increased serum AA concentrations and increased expression of the key AA metabolic enzyme cyclooxygenase-2 (COX-2). AA incubation weakened the contraction of denuded coronary arteries, reduced the expression of contraction markers, and increased the fluorescence intensity of synthetic and ERS response markers in coronary arteries. Further investigation of CASMCs revealed that AA-induced phenotypic transformation was mediated via the ERS pathway.

CONCLUSIONS

ERS and AA were found to be stimulated in CASMCs following an HS diet. AA triggers an ERS response through COX-2 catalysis, and the downstream inositol requiring enzyme 1 - X-box binding protein-1 - osteopontin pathway may contribute to the AA-induced phenotypic transformation of CASMCs, resulting in dysfunctional coronary tension. This study may provide potential therapeutic targets for cardiovascular diseases associated with excessive AA-derived ERS.

Enhanced Production of EPA-Derived Anti-Inflammatory Metabolites after Oral Administration of a Novel Self-Emulsifying Highly Purified EPA Ethyl Ester Formulation (MND-2119)

AIMS

MND-2119 is a novel once-daily dose self-emulsifying formulation of highly purified eicosapentaenoic acid ethyl ester (EPA-E) and is approved as an antihyperlipidemia agent in Japan. It has improved absorption and achieves higher plasma EPA concentrations at Cmax than conventional EPA-E. In the JELIS trial, concomitant use of EPA-E with statin therapy significantly reduced atherosclerotic cardiovascular disease (ASCVD) risks. As a potential mechanism of action of EPA, endogenous formation of EPA-derived anti-inflammatory metabolites is receiving greater attention. This study aims to investigate the endogenous formation of EPA-derived anti-inflammatory metabolites following single and multiple administrations of MND-2119.

METHODS

Healthy adult male subjects were randomly assigned to a nonintervention (control) group, MND-2119 2-g/day group, MND-2119 4-g/day group, or EPA-E 1.8-g/day group for 7 days (N=8 per group). Plasma fatty acids and EPA-derived metabolites were evaluated. Peripheral blood neutrophils were isolated, and the production of EPA-derived metabolites from in vitro stimulated neutrophils was evaluated.

RESULTS

After single and multiple administrations of MND-2119 2 g/day, there were significant increases in plasma EPA concentration, 18-hydroxyeicosapentaenoic acid (18-HEPE), and 17,18-epoxyeicosatetraenoic acid compared with those of EPA-E 1.8 g/day. They were further increased with MND-2119 4 g/day administration. In neutrophils, the EPA concentration in the MND-2119 2-g/day group was significantly higher compared with that in the EPA-E 1.8-g/day group after multiple administration, and 18-HEPE production was positively correlated with EPA concentration. No safety issues were noted.

CONCLUSIONS

These results demonstrate that MND-2119 increases the plasma and cellular concentrations of EPA and EPA-derived metabolites to a greater extent than conventional EPA-E formulations.

Changes in the Eicosapentaenoic Acid to Arachidonic Acid Ratio in Serum over 10 Years in a Japanese Community: The Hisayama Study

AIM

Circulating omega-3 and omega-6 polyunsaturated fatty acids may to contribute to cardiovascular health at the population level. Over a decade, we investigated changes in the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio, and in serum concentrations of the individual fatty acids, in a Japanese community.

METHODS

Community surveys took place in 2002-2003 and 2012-2013 in a rural area of Japan. The community surveys included 3,194 and 3,220 community dwellers aged ≥ 40 years who did not take EPA medication in 2002-2003 and 2012-2013, respectively. Fatty acid fractionations in serum were measured using a gas chromatography method. Changes in the serum EPA/AA ratio over time were examined using linear mixed models.

RESULTS

Overall, the average serum EPA/AA ratio decreased over the 10 years. A decreasing trend in the serum EPA/AA ratio occurred in all age groups except participants aged ≥ 80 years, with larger decreases in the younger age groups. A similar decline in serum EPA/AA ratio occurred in participants with and those without lipid-lowering therapy. Serum EPA concentrations were slightly increased in the whole population but remained stable or even decreased in participants aged 40-69. In contrast, the average serum AA concentrations increased in all age groups.

CONCLUSION

In a Japanese community, the serum EPA/AA ratio decreased over 10 years at the population level, especially in middle-aged participants.