Low levels of linoleic acid and α-linolenic acid and high levels of arachidonic acid in plasma phospholipids are associated with hypertension

Comparative Transcriptomic and Lipidomic Analysis of Fatty Acid Accumulation in Three Camellia oleifera Varieties During Seed Maturing

Camellia oleifera, a major woody oil crop in China, produces tea oil rich in unsaturated fatty acids, earning it names like liquid gold and eastern olive oil. This study provides an integrated investigation of the transcriptome and lipidome within seeds at the maturing process across three C. oleifera varieties, revealing a significant relationship between fatty acid production and genes involved in lipid synthesis. Through transcriptomic analysis, 26,344 genes with varied expression were found. Functional enrichment analysis highlighted that pathways related to starch and sucrose metabolism, plant hormone signal transduction, and lipid accumulation were highly enriched among the differentially expressed genes. Coordinated high expression of key genes (ACCase, KAS I, KAS II, KAS III, KAR, HAD, EAR, SAD, LPAAT, LACS, DGAT, PDAT) during the late maturation stage contributes largely to high oil content. Additionally, expression variations of SAD and FADs among different varieties were explored. The analysis suggests that high expression of genes such as FAD3, FAD7, and FAD8 notably increased linolenic acid content. This research provides new insights into the molecular mechanisms of oil biosynthesis in C. oleifera, offering valuable references for improving yield and quality.

Association of dietary fatty acid intake with hypertension in children and adolescents: evidence from the NHANES 2005-2018

Aim

This study aims to evaluate the association between dietary fatty acid intake and hypertension in children and adolescents.

Methods

This cross-sectional study used data of children and adolescents aged 8-17 years from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Dietary intake of total fat and fatty acid was evaluated via two 24-h dietary recall interviews. Multivariate logistic regression models were used to assess the association between fatty acid intake and hypertension, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated. A subgroup analysis was conducted according to gender, age, and body mass index Z-score.

Results

This study included 13,330 subjects, of which 11,614 were non-hypertensive and 1,716 were hypertensive. Higher intake of total polyunsaturated fatty acids (PUFAs) was associated with significantly lower odds of hypertension (OR = 0.85, 95% CI: 0.74-0.97, P = 0.018). No significant associations were found between the density of total saturated fatty acid, monounsaturated fatty acids, and PUFAs and the odds of hypertension (all P > 0.05). Increased intake of omega-3 (OR = 0.82, 95% CI: 0.72-0.93, P = 0.002) and omega-6 (OR = 0.86, 95% CI: 0.75-0.98, P = 0.025) PUFAs, octadecatrienoic acid (OR = 0.82, 95% CI: 0.72-0.93, P = 0.003), and octadecadienoic acid (OR = 0.86, 95% CI: 0.75-0.98, P = 0.025) was associated with significantly lower odds of hypertension, and individuals with higher omega-6/omega-3 ratio had significantly higher odds of hypertension (OR = 1.09, 95% CI: 1.02-1.17, P = 0.025). The density of omega-3 PUFAs (OR = 0.86, 95% CI: 0.78-0.95, P = 0.004) and octadecatrienoic acid (OR = 0.87, 95% CI: 0.78-0.96, P = 0.006) was inversely associated with the odds of hypertension, and the omega-6/omega-3 ratio was positively associated with the odds of hypertension (OR = 1.09, 95% CI: 1.02-1.17, P = 0.012).

Conclusion

Total PUFA intake was negatively associated with the odds of hypertension in children and adolescents. Higher intake of omega-3 and omega-6 PUFAs, octadecatrienoic acid, and octadecadienoic acid, as well as density of omega-3 PUFAs and octadecatrienoic acid, was associated with lower odds of hypertension.

Decompression Mechanism of Radish Seed in Prehypertension Rats through Integration of Transcriptomics and Metabolomics Methods

Radish seed (RS), the dried ripe seed of Raphanus sativus L., is widely used in traditional Chinese medicine (TCM) to reduce blood pressure. However, the molecular and pharmacological mechanisms underlying its therapeutic effects are still unclear. In this study, we analyzed the effects of RS in a rat model of prehypertension and assessed the mechanistic basis by integrating transcriptomics and metabolomics. RS administration significantly reduced blood pressure in prehypertensive male Wistar rats, negatively regulated endothelin-1, increased nitric oxide levels, and reduced the exfoliation of endothelium cells. In vitro vascular ring experiments further confirmed the effects of RS on vascular endothelial cells. Furthermore, we identified 65 differentially expressed genes (DEGs; P _adj < 0.05 and fold change (FC) > 2) and 52 metabolites (VIP > 1, P < 0.05 and FC ≥ 2 or ≤0.5) in the RS intervention group using RNA-seq and UPLC-MS/MS, respectively. A network of the DEGs and the metabolites was constructed,q which indicated that RS regulates purine metabolism, linoleic acid metabolism, arachidonic acid metabolism, circadian rhythm, and phosphatidylinositol signaling pathway, and its target genes are Pik3c2a, Hspa8, Dnaja1, Arntl, Ugt1a1, Dbp, Rasd1, and Aldh1a3. Thus, the antihypertensive effects of RS can be attributed to its ability to improve vascular endothelial dysfunction by targeting multiple genes and pathways. Our findings provide new insights into the pathological mechanisms underlying prehypertension, along with novel targets for the prevention and treatment of hypertension.

Polyunsaturated fatty acids produce a range of activators for heterogeneous IKs channel dysfunction

Repolarization and termination of the ventricular cardiac action potential is highly dependent on the activation of the slow delayed-rectifier potassium IKs channel. Disruption of the IKs current leads to the most common form of congenital long QT syndrome (LQTS), a disease that predisposes patients to ventricular arrhythmias and sudden cardiac death. We previously demonstrated that polyunsaturated fatty acid (PUFA) analogues increase outward K+ current in wild type and LQTS-causing mutant IKs channels. Our group has also demonstrated the necessity of a negatively charged PUFA head group for potent activation of the IKs channel through electrostatic interactions with the voltage-sensing and pore domains. Here, we test whether the efficacy of the PUFAs can be tuned by the presence of different functional groups in the PUFA head, thereby altering the electrostatic interactions of the PUFA head group with the voltage sensor or the pore. We show that PUFA analogues with taurine and cysteic head groups produced the most potent activation of IKs channels, largely by shifting the voltage dependence of activation. In comparison, the effect on voltage dependence of PUFA analogues with glycine and aspartate head groups was half that of the taurine and cysteic head groups, whereas the effect on maximal conductance was similar. Increasing the number of potentially negatively charged moieties did not enhance the effects of the PUFA on the IKs channel. Our results show that one can tune the efficacy of PUFAs on IKs channels by altering the pKa of the PUFA head group. Different PUFAs with different efficacy on IKs channels could be developed into more personalized treatments for LQTS patients with a varying degree of IKs channel dysfunction.

The Short Overview on the Relevance of Fatty Acids for Human Cardiovascular Disorders

This review presents existing evidence of the influence of saturated and unsaturated fatty acids on cardiovascular diseases (CVD). Data are discussed regarding the roles of the most relevant fatty acids, such as myristic (C14:0), palmitic (C16:0), stearic (C18:0), palmitoleic (C16:1), oleic (C18:1), linoleic (C18:2), α-linolenic (C18:3, ω-3), γ-linolenic (C18:3, ω-6), arachidonic (C20:4), eicosapentaenoic (C20:5), docosahexaenoic (C22:6), and docosapentaenoic (C22:5) acid. The accumulated knowledge has expanded the understanding of the involvement of fatty acids in metabolic processes, thereby enabling the transition from basic exploratory studies to practical issues of application of these biomolecules to CVD treatment. In the future, these findings are expected to facilitate the interpretation and prognosis of changes in metabolic lipid aberrations in CVD.

α-Linolenic acid but not linolenic acid protects against hypertension: critical role of SIRT3 and autophagic flux

Although dietary α-linolenic acid (ALA) or linolenic acid (LA) intake was reported to be epidemiologically associated with a lower prevalence of hypertension, recent clinical trials have yielded conflicting results. Comparable experimental evidence for the roles of these two different fatty acids is still lacking and the underlying mechanisms need to be further elucidated. Our data showed that ALA but not LA supplementation alleviated systolic blood pressure elevation and improved ACh-induced, endothelium-dependent vasodilation in both spontaneously hypertensive rats (SHRs) and AngII-induced hypertensive mice. In addition, SHRs displayed reduced vascular Sirtuin 3 (SIRT3) expression, subsequent superoxide dismutase 2 (SOD2) hyperacetylation and mitochondrial ROS overproduction, all of which were ameliorated by ALA but not LA supplementation. In primary cultured endothelial cells, ALA treatment directly inhibited SIRT3 reduction, SOD2 hyperacetylation, mitochondrial ROS overproduction and alleviated autophagic flux impairment induced by AngII plus TNFα treatment. However, these beneficial effects of ALA were completely blocked by silencing SIRT3. Restoration of autophagic flux by rapamycin also inhibited mitochondrial ROS overproduction in endothelial cells exposed to AngII plus TNFα. More interestingly, SIRT3 KO mice developed severe hypertension in response to a low dose of AngII infusion, while ALA supplementation lost its anti-hypertensive and endothelium-protective effects on these mice. Our findings suggest that ALA but not LA supplementation improves endothelial dysfunction and diminishes experimental hypertension by rescuing SIRT3 impairment to restore autophagic flux and mitochondrial redox balance in endothelial cells.

Differential miRNA expression analysis of extracellular vesicles from brain microvascular pericytes in spontaneous hypertensive rats

OBJECTIVE

This study is to explore the exact roles of extracellular vesicle (EVs) miRNAs from brain microvascular pericytes in the pathogenesis of hypertension.

RESULTS

Forty-eight significantly differentially expressed miRNAs were identified, of which 17 were found to be upregulated and 31 were found to be downregulated in brain microvascular pericytes of spontaneous hypertensive rats, compared with that of normotension Wistar Kyoto rats. The GO enrichment analysis verified that the target genes were enriched in signaling pathways and molecular functions, such as metal ion binding, nucleotide binding and ATP binding. The KEGG analysis indicated that the target genes were enriched in Linoleic acid, alpha-linolenic acid and sphingolipid metabolism pathways.

CONCLUSIONS

Several EV derived miRNAs, such as miR-21-5p, let-7c-5p and let-7a-5p, were found to be abnormally expressed in brain microvascular pericytes obtained from spontaneous hypertensive rats, compared with that of normotension Wistar Kyoto rats. The results of our research provide more insights into the functional link between brain microvascular pericytes and the pathogenesis of hypertension.

Importance of Flaxseed and its Components in the Management of Hypertension

This review paper describes the effects of flaxseed and its components (flax oil, secoisolariciresinol diglucoside [SDG], flax lignan complex [FLC], and flaxseed protein hydrolysate [FPH]) on blood pressure (BP) in Sprague Dawley rats (SDR), spontaneously hypertensive rats (SHR), and humans. Flaxseed, flax oil, and FLC had variable effects on BP in humans, while SDG and FPH significantly reduced the BP in SDR and SHR. The effect of SDG was dose-dependent and long lasting. The lowering of BP is mediated through inhibition of soluble epoxide by α -linolenic acid in flax oil, stimulation of guanylate cyclase and inhibition of angiotensin converting enzyme (ACE) by SDG, and inhibition of renin and ACE activity by FPH. Flaxseed, flax oil, and FLC have variable effects on BP (none, slight, and significant). They are effective in lowering BP in individuals with hypertension and metabolic syndrome but ineffective in healthy individuals' ineffectiveness of flaxseed and its compounds in lowering BP may be due to their low doses, long interval of dosing, short duration of consumption, and patient status. In conclusion, the data at present suggest that flaxseed, flax oil, and FLC cannot serve as therapeutic agents for the treatment of hypertension. However, they can be used as an adjunct in the treatment of hypertension. A clinical trial should be conducted of these agents with higher doses which would be given twice daily for long duration. Pure SDG and FPS may serve as therapeutic agents for the treatment of hypertension but they have not been tried in humans.

Study on the Antihypertensive Mechanism of Astragalus membranaceus and Salvia miltiorrhiza Based on Intestinal Flora-Host Metabolism

Our previous studies have shown that the combination of Astragalus membranaceus and Salvia miltiorrhiza (HD) had a good antihypertensive effect, but its potential mechanism remained unclear. This study aimed to investigate the role of intestinal flora and serum metabolism induced by HD against hypertension. 16 spontaneous hypertensive rats (SHRs) were divided into HD group (5.9 g/kg) and model group (M) (normal saline), with eight Wistar-Kyoto (WKY) rats as control group (W) (normal saline). Rats were fed by gavage once a day for 28 days. The changes of intestinal flora and serum metabolism were analyzed by 16S rDNA sequencing and LC-MS/MS assay. HD decreased blood pressure steadily, improved the structure and composition of imbalance flora in SHRs, increased the abundance and diversity of flora, and decreased flora Firmicutes to Bacteroidetes (F/B) ratio. Rumen bacterium NK4A214, Clostridium sp. MC 40 increased remarkably in M group. Akkermansia, Akkermansia muciniphila, and Lactobacillus intestinalis increased significantly in HD group, which were functionally related to the significant increase of Lachnoclostridium, Faecalibaculum, and Lactobacillus reuteri in W group, which were all probiotics producing butyric acid, lactic acid, and regulating inflammation and other antihypertensive related factors. HD also changed the serum metabolic pattern of SHRs. 16 potential biomarkers related to inflammation, vasodilation, steroid hormones, oxidative stress, and etc. changed significantly, mainly enriched in arachidonic acid metabolism, tryptophan metabolism, steroid hormone biosynthesis, and glutathione metabolism. The correlation analysis demonstrated that the dominant genius and species in three groups were highly correlated with steroid hormone biosynthesis, arachidonic acid metabolism, tryptophan metabolism, and vitamin B6 metabolism. Our research indicated that HD had a good antihypertensive effect, which may be driven by the protective intestinal flora and beneficial metabolites induced by it, and the metabolites were closely related to the changes of intestinal flora. It provided new insights for the antihypertensive mechanism of HD.

Replacing Saturated Fat With Walnuts or Vegetable Oils Improves Central Blood Pressure and Serum Lipids in Adults at Risk for Cardiovascular Disease: A Randomized Controlled-Feeding Trial

Background Walnuts have beneficial effects on cardiovascular risk factors, but it is unclear whether these effects are attributable to the fatty acid ( FA ) content, including α-linolenic acid ( ALA ), and/or bioactives. Methods and Results A randomized, controlled, 3-period, crossover, feeding trial was conducted in individuals at risk for cardiovascular disease (n=45). Following a 2-week standard Western diet run-in (12% saturated FAs [ SFA ], 7% polyunsaturated FAs, 12% monounsaturated FAs), participants consumed 3 isocaloric weight-maintenance diets for 6 weeks each: a walnut diet ( WD ; 7% SFA , 16% polyunsaturated FAs, 3% ALA , 9% monounsaturated FAs); a walnut FA -matched diet; and an oleic acid-replaced- ALA diet (7% SFA , 14% polyunsaturated FAs, 0.5% ALA , 12% monounsaturated FAs), which substituted the amount of ALA from walnuts in the WD with oleic acid. This design enabled evaluation of the effects of whole walnuts versus constituent components. The primary end point, central systolic blood pressure, was unchanged, and there were no significant changes in arterial stiffness. There was a treatment effect ( P=0.04) for central diastolic blood pressure; there was a greater change following the WD versus the oleic acid-replaced-ALA diet (-1.78±1.0 versus 0.15±0.7 mm Hg, P=0.04). There were no differences between the WD and the walnut fatty acid-matched diet (-0.22±0.8 mm Hg, P=0.20) or the walnut FA-matched and oleic acid-replaced-ALA diets ( P=0.74). The WD significantly lowered brachial and central mean arterial pressure. All diets lowered total cholesterol, LDL (low-density lipoprotein) cholesterol, HDL (high-density lipoprotein) cholesterol, and non- HDL cholesterol. Conclusions Cardiovascular benefits occurred with all moderate-fat, high-unsaturated-fat diets. As part of a low- SFA diet, the greater improvement in central diastolic blood pressure following the WD versus the oleic acid-replaced-ALA diet indicates benefits of walnuts as a whole-food replacement for SFA . Clinical Trial Registration URL : https://www.clinicaltrials.gov . Unique identifier: NCT02210767.

Chokeberry Juice Containing Polyphenols Does Not Affect Cholesterol or Blood Pressure but Modifies the Composition of Plasma Phospholipids Fatty Acids in Individuals at Cardiovascular Risk

Chokeberry polyphenols have been suggested to reduce cholesterol and blood pressure and thus protect against cardiovascular diseases (CVD), but the evidence in humans is limited and inconsistent. This randomized double-blinded three-parallel groups trial investigated the changes in various anthropometric and clinical biomarkers, and in plasma phospholipids fatty acids (PPFA) in volunteers at cardiovascular risk after a four-week intervention with 100 mL/day of (1) chokeberry juice with a high-dose of polyphenols (1177.11 mg gallic acid equivalents, GAE); (2) chokeberry juice with a low-dose of polyphenols (294.28 mg GAE) and; (3) a nutritionally matched polyphenol-free placebo drink. Our results indicate that the intake of chokeberry juice containing either the low or the high dose of polyphenols cannot be linked with a reduction in total- and low-density lipoprotein (LDL)cholesterol or in systolic (SBP) and diastolic (DBP) blood pressure in comparison with the consumption of the placebo drink. However, we found evidence of moderate changes in the PPFA, i.e., increased saturated fatty acids (SFA), mostly palmitic acid, and reduced n-6 polyunsaturated fatty acids (PUFA), principally linoleic acid (LA) with the intake of chokeberry against the placebo. These effects may be associated with the polyphenols but we could not differentiate a clear dose-response effect. Further research is still needed to elucidate the contribution of the polyphenolic fraction to the potential cardiovascular effects of the chokeberry and to build up the evidence of its potential benefit via the modulation of PPFA composition.