Phosphorylation of Insig-2 mediates inhibition of fatty acid synthesis by polyunsaturated fatty acids.

Insig-1 and Insig-2 are endoplasmic reticulum (ER) proteins that inhibit lipid synthesis by blocking transport of sterol regulatory element-binding proteins (SREBP-1 and SREBP-2) from ER to Golgi. In the Golgi, SREBPs are processed proteolytically to release their transcription-activating domains, which enhance the synthesis of fatty acids, triglycerides, and cholesterol. Heretofore, the two Insigs have redundant functions, and there is no rationale for two isoforms. The current data identify a specific function for Insig-2. We show that eicosapentaenoic acid (EPA), a polyunsaturated fatty acid, inhibits fatty acid synthesis in human fibroblasts and rat hepatocytes by activating adenylate cyclase, which induces protein kinase A (PKA) to phosphorylate serine-106 in Insig-2. Phosphorylated Insig-2 inhibits the proteolytic processing of SREBP-1, thereby blocking fatty acid synthesis. Phosphorylated Insig-2 does not block the processing of SREBP-2, which activates cholesterol synthesis. Insig-1 lacks serine-106 and is not phosphorylated at this site. EPA inhibition of SREBP-1 processing was reduced by the replacement of serine-106 in Insig-2 with alanine or by treatment with KT5720, a PKA inhibitor. Inhibition did not occur in mutant human fibroblasts that possess Insig-1 but lack Insig-2. These data provide an Insig-2-specific mechanism for the long-known inhibition of fatty acid synthesis by polyunsaturated fatty acids.

ω-3 PUFA for Secondary Prevention of White Matter Lesions and Neuronal Integrity Breakdown in Older Adults: A Randomized Clinical Trial.

Importance: Older adults with lower intake and tissue levels of long-chain ω-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6) have more brain white matter lesions (WMLs), an association suggesting that small-vessel ischemic disease, a major contributor to the development of dementia, including Alzheimer disease, may be preventable through ω-3 treatment. Objective: To determine whether ω-3 treatment reduces WML accumulation in older adults without dementia harboring WMLs and with suboptimal ω-3 status. Design, Setting, and Participants: This quadruple-blinded, placebo-controlled, randomized clinical trial with treatment stratification by apolipoprotein E ε4 allele (APOE*E4) carrier status used linear mixed-effects models to estimate mean annual change between groups. The study was conducted at Oregon Health & Science University, a major academic medical center in the Pacific Northwest, from May 2014 to final participant visit in September 2019. Data analysis concluded in July 2022. Participants were adults without dementia aged 75 years and older with WMLs greater than or equal to 5 cm3 and plasma ω-3 PUFA less than 5.5 weight percentage of total. Intervention: Three-year treatment with 1.65 g of ω-3 PUFA (975 mg of EPA and 650 mg of DHA) vs a soybean oil placebo matched for taste, smell, and appearance. Main Outcomes and Measures: The primary outcome was annual WML progression measured using magnetic resonance imaging. Secondary outcomes included diffusion tensor imaging of fractional anisotropy (DTI-FA), representing neuronal integrity breakdown. Results: A total of 102 participants (62 women [60.8%]; mean age, 81 years [range, 75-96 years]) were equally randomized, 51 per treatment group. Although the ω-3 group had less annual WML accumulation than the placebo group, the difference was not statistically significant (1.19 cm3 [95% CI, 0.64-1.74 cm3] vs 1.34 cm3 [95% CI, 0.80-1.88 cm3]; P = .30). Similarly, the ω-3 group had less annual DTI-FA decline than the placebo group, but the difference was not statistically significant (-0.0014 mm2/s [95% CI, -0.0027 to 0.0002 mm2/s] vs -0.0027 mm2/s [95% CI, -0.0041 to -0.0014 mm2/s]; P = .07). Among APOE*E4 carriers, the annual DTI-FA decline was significantly lower in the group treated with ω-3 than the placebo group (-0.0016 mm2/s [95% CI, -0.0032 to 0.0020 mm2/s] vs -0.0047 mm2/s [95% CI, -0.0067 to -0.0025 mm2/s]; P = .04). Adverse events were similar between treatment groups. Conclusions and Relevance: In this 3-year randomized clinical trial, ω-3 treatment was safe and well-tolerated but failed to reach significant reductions in WML accumulation or neuronal integrity breakdown among all participants, which may be attributable to sample size limitations. However, neuronal integrity breakdown was reduced by ω-3 treatment in APOE*E4 carriers, suggesting that this treatment may be beneficial for this specific group. Trial Registration: ClinicalTrials.gov Identifier: NCT01953705.

Omega-3 Fatty Acids and Arrhythmias.

The pro- and antiarrhythmic effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been extensively studied in preclinical and human trials. Despite early evidence of an antiarrhythmic role of n-3 PUFA in the prevention of sudden cardiac death and postoperative and persistent atrial fibrillation (AF), subsequent well-designed randomized trials have largely not shown an antiarrhythmic benefit. Two trials that tested moderate and high-dose n-3 PUFA demonstrated a reduction in sudden cardiac death, but these findings have not been widely replicated, and the potential of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to reduce arrhythmic death in combination, or as monotherapy, remains uncertain. The accumulated clinical evidence does not support supplementation of n-3 PUFA for postoperative AF or secondary prevention of AF. Several large, contemporary, randomized controlled trials of high-dose n-3 PUFA for primary or secondary cardiovascular prevention have demonstrated a small, significant, dose-dependent increased risk of incident AF compared with mineral oil or corn oil comparator. These findings were reproduced with both icosapent ethyl monotherapy and a mixed EPA+DHA formulation. The proarrhythmic mechanism of increased AF in contemporary cohorts exposed to high-dose n-3 PUFA is unknown. EPA and DHA and their metabolites have pleiotropic cardiometabolic and pro- and antiarrhythmic effects, including modification of the lipid raft microenvironment; alteration of cell membrane structure and fluidity; modulation of sodium, potassium, and calcium currents; and regulation of gene transcription, cell proliferation, and inflammation. Further characterization of the complex association between EPA, EPA+DHA, and DHA and AF is needed. Which formulations, dose ranges, and patient subgroups are at highest risk, remain unclear.

Efficient Expression and Application of a Modified Rhizomucor miehei Lipase for Simultaneous Production of Biodiesel and Eicosapentaenoic Acid Ethyl Ester from Nannochloropsis Oil.

Few reports exist on one-step enzymatic methods for the simultaneous production of biodiesel and eicosapentaenoic acid ethyl ester (EPA-EE), a high-value pharmaceutical compound. This study aimed to efficiently express Rhizomucor miehei lipase (pRML) in Pichia pastoris X-33 via propeptide mutation and high-copy strain screening. The mutated enzyme was then used to simultaneously catalyze the production of both biodiesel and EPA-EE. The P46N mutation in the propeptide (P46N-pRML) significantly boosted its production, with the four-copy strain increasing enzyme yield by 3.7-fold, reaching 3425 U/mL. Meanwhile, its optimal temperature increased to 45-50 °C, pH expanded to 7.0-8.0, specific activity doubled, Km reduced to one-third, and kcat/Km increased 7-fold. Notably, P46N-pRML efficiently converts Nannochloropsis gaditana oil's eicosapentaenoic acid (EPA). Under optimal conditions, it achieves up to 93% biodiesel and 92% EPA-EE yields in 9 h. Our study introduces a novel, efficient one-step green method to produce both biodiesel and EPA-EE using this advanced enzyme.

Optimization of concentrations of different n-3PUFAs on antioxidant capacity in mouse hepatocytes.

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), mainly including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), possess antioxidant properties and play a crucial role in growth and development. However, the combined effects of ALA, EPA, and DHA at different concentrations have rarely been reported. This work explored the effects of EPA, ALA, and DHA on the viability and antioxidant capacity of mouse hepatocytes, with the objective of enhancing the antioxidant capacity. Within the appropriate concentration range, cell viability and the activity of glutathione S-transferase, superoxide dismutase, and catalase were increased, while the oxidation products of malondialdehyde and the level of intracellular reactive oxygen species were obviously reduced. Thus, oxidative stress was relieved, and cellular antioxidant levels were improved. Finally, response surface optimization was carried out for EPA, ALA, and DHA, and the model was established. The antioxidant capacity of the cells was highest at EPA, ALA, and DHA concentrations of 145.46, 405.05, and 551.52 µM, respectively. These findings lay the foundation for further exploration of the interactive mechanisms of n-3 PUFAs in the body, as well as their applications in nutraceutical food.

Linear isomer but not branched isomers of perfluorooctane sulfonate in plasma is associated with eicosapentaenoic acid, a seafood consumption biomarker.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are global contaminants. Seafood consumption is a possible PFAS exposure route to humans while the isomer specific analysis has not been conducted. METHODS: Perfluorooctane sulfonate (PFOS), perfluoroheptane sulfonate (PFHpS) and perfluorohexane sulfonate (PFHxS) were investigated in residents of Kyoto, Japan (n = 51). The relationship between plasma PFAS and seafood consumption biomarker, the ratio of eicosapentaenoic acid to arachidonic acid (EPA/AA) was examined by multiple regression analysis. RESULTS: Linear PFOS concentrations showed a significant positive correlation with the EPA/AA ratio in plasma samples (ß = 6.80, p = 0.0014). Linear PFHpS was marginally associated with EPA/AA ratio (ß = 0.178, p = 0.0874). Branched PFOS isomers and PFHxS had no associations with EPA/AA ratios. CONCLUSION: Seafood intake may be a significant exposure pathway for PFAS, such as PFOS but the isomers differ.

The Intake of Omega-3 Fatty Acids, the Omega-3 Index in Pregnant Women, and Their Correlations with Gestational Length and Newborn Birth Weight.

BACKGROUND: During pregnancy, the demand for omega-3 fatty acids, notably docosahexaenoic acid (DHA), escalates for both maternal and foetal health. Insufficient levels can lead to complications and can affect foetal development. This study investigated omega-3 status and its relation to dietary intake in pregnant Latvian women, along with its impact on gestational duration and newborn birth weight. METHODS: The study comprised 250 pregnant and postpartum women with a mean age of 31.6 ± 4.8 years. Nutrition and omega-3 supplementation data were collected through a questionnaire covering 199 food items and 12 supplements. Fatty acids in erythrocyte membrane phospholipids were analysed via gas chromatography with flame ionization detection. RESULTS: The median omega-3 fatty acid intake, including eicosapentaenoic acid (EPA) and DHA from diet and supplements, was 0.370 g/day, which is deemed sufficient. However, the median weekly fish intake (126.0 g) and daily nut/seed intake (7.4 g) were insufficient. The median omega-3 supplement intake was 1.0 g/day. No correlation between omega-3 supplement intake and the omega-3 index was observed. There was a weak correlation between the DHA intake from fish and the omega-3 index (r = 0.126, p = 0.047), while a significant correlation between the total EPA and DHA intake from various sources and the omega-3 index was noted (r = 0.163, p = 0.01). Most women (61.6%) had an omega-3 index < 4%, while 34.8% had an index between 4 and 8%, and only 3.6% had an index > 8%. Notably, significant differences in EPA levels and the omega-3 index were found among respondents with differing infant birth weights (p < 0.05). CONCLUSIONS: The omega-3 intake during pregnancy adheres to the established guidelines, although fish consumption remains insufficient. A preconception evaluation of the omega-3 index is advocated to optimize prenatal intake. The indications suggest potential correlations between EPA levels, the omega-3 index, and infant birth weight.

Eicosapentaenoic Acid Improves Endothelial Nitric Oxide Bioavailability Via Changes in Protein Expression During Inflammation.

BACKGROUND: Endothelial cell (EC) dysfunction involves reduced nitric oxide (NO) bioavailability due to NO synthase uncoupling linked to increased oxidation and reduced cofactor availability. Loss of endothelial function and NO bioavailability are associated with inflammation, including leukocyte activation. Eicosapentaenoic acid (EPA) administered as icosapent ethyl reduced cardiovascular events in REDUCE-IT (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial) in relation to on-treatment EPA blood levels. The mechanisms of cardiovascular protection for EPA remain incompletely elucidated but likely involve direct effects on the endothelium. METHODS AND RESULTS: In this study, human ECs were treated with EPA and challenged with the cytokine IL-6 (interleukin-6). Proinflammatory responses in the ECs were confirmed by ELISA capture of sICAM-1 (soluble intercellular adhesion molecule-1) and TNF-α (tumor necrosis factor-α). Global protein expression was determined using liquid chromatography-mass spectrometry tandem mass tag. Release kinetics of NO and peroxynitrite were monitored using porphyrinic nanosensors. IL-6 challenge induced proinflammatory responses from the ECs as evidenced by increased release of sICAM-1 and TNF-α, which correlated with a loss of NO bioavailability. ECs pretreated with EPA modulated expression of 327 proteins by >1-fold (P<0.05), compared with IL-6 alone. EPA augmented expression of proteins involved in NO production, including heme oxygenase-1 and dimethylarginine dimethylaminohydrolase-1, and 34 proteins annotated as associated with neutrophil degranulation. EPA reversed the endothelial NO synthase uncoupling induced by IL-6 as evidenced by an increased [NO]/[peroxynitrite] release ratio (P<0.05). CONCLUSIONS: These direct actions of EPA on EC functions during inflammation may contribute to its distinct cardiovascular benefits.

Carrageenan-ferrocene-eicosapentaenoic acid composite hydrogel induce ferroptosis and apoptosis for anti-tumor recurrence and metastasis.

The immune-suppressive microenvironment of solid tumors is a key factor limiting the effectiveness of immunotherapy, which seriously threatens human life and health. Ferroptosis and apoptosis are key cell-death pathways implicated in cancers, which can synergistically activate tumor immune responses. Here, we developed a multifunctional composite hydrogel (CE-Fc-Gel) based on the self-assembly of poloxamer 407, cystamine-linked ιota-carrageenan (CA)-eicosapentaenoic acid (EPA), and ferrocene (Fc). CE-Fc-Gel improved targeting in tumor microenvironment due to its disulfide bonds. Moreover, CE-Fc-Gel promoted lipid peroxidation, enhanced reactive oxygen species (ROS) production, and decreased glutathione peroxidase 4 (GPX4), inducing ferroptosis by the synergistic effect of Fc and EPA. CE-Fc-Gel induced apoptosis and immunogenic cell death (ICD), thereby promoting dendritic cells (DCs) maturation and T cell infiltration. As a result, CE-Fc-Gel significantly inhibited primary and metastatic tumors in vivo. Our findings provide a novel strategy for enhancing tumor immunotherapy by combining apoptosis, ferroptosis, and ICD.

The benefits of flushing with Lemuru fish oil as a source of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on the performance of reproductive parameters in Garut ewes.

This study aimed to evaluate and analyze the effects of a flushing diet containing Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA) from Lemuru (Sardinella sp) fish oil on the reproductive performance parameters of Garut ewes. Forty (n = 40) primiparous Garut ewes aged 12-14 months with an average body weight of 28.92 ± 4.94 kg were assigned into four experimental treatment groups. The experimental diets contained roughage: concentrate (30:70%) designated as control concentrate (CNT), flushing concentrate with 6% palm oil (PO), flushing concentrate with 3% palm oil mixed with 3% lemuru oil as DHA and EPA sources (PFO), and flushing concentrate with the addition of 6% lemuru oil (FO). Treatment animals were fed two weeks before and after conception and parturition (8 weeks of total flushing treatment). The addition of fish oil at either 3% (PFO) or 6% (FO) resulted in significantly higher reproductive performance of ewes by increasing the litter size, as reflected by the birth of multiple kids (P < 0.05) compared to CNT and PO. Adding fish oil (PFO and FO) also maintains gestation, resulting in increased lamb yield, especially in the FO treatment, which yields the highest lamb yield (0% single lamb birth). The lamb male ratio was also higher with fish oil supplementation (PFO and PO) (P < 0.05). This research revealed a positive effect of 6% Lemuru oil on decreasing embryo loss and increasing the proportion of twin births. These findings thus support the hypothesis that ration flushing with double the required DHA and EPA from 6% Lemuru fish oil (FO) resulted in significantly higher reproductive performance in Garut sheep.

The bioconversion of dietary α-linolenic acid to eicosapentaenoic acid in Bombyx mori.

n-3 Long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), including eicosapentaenoic acid (EPA), are essential multifunctional nutrients in animals. Microorganisms such as microalgae are known to be n-3 LC-PUFA producers in aquatic environments. Various aquatic invertebrates, including Harpacticoida copepods, and a few terrestrial invertebrates, such as the nematode Caenorhabditis elegans, possess n-3 LC-PUFA biosynthetic enzymes. However, the capacity for n-3 LC-PUFA biosynthesis and the underlying molecular mechanisms in terrestrial insects are largely unclear. In this study, we investigated the fatty acid biosynthetic pathway in the silkworm Bombyx mori and found that EPA was present in silkworms throughout their development. Stable isotope tracing revealed that dietary α-linolenic acid (ALA) was metabolized to EPA in silkworm larvae. These results indicated that silkworms synthesize EPA from ALA. Given that EPA is enriched in the central nervous system, we propose that EPA confers optimal neuronal functions, similar to docosahexaenoic acid, in the mammalian nervous system.

Eicosapentaenoic Acid Rescues Cav1.2-L-Type Ca2+ Channel Decline Caused by Saturated Fatty Acids via Both Free Fatty Acid Receptor 4-Dependent and -Independent Pathways in Cardiomyocytes.

Dietary intake of omega-3 polyunsaturated fatty acids (eicosapentaenoic acid, EPA) exerts antiarrhythmic effects, although the mechanisms are poorly understood. Here, we investigated the possible beneficial actions of EPA on saturated fatty acid-induced changes in the L-type Ca2+ channel in cardiomyocytes. Cardiomyocytes were cultured with an oleic acid/palmitic acid mixture (OAPA) in the presence or absence of EPA. Beating rate reduction in cardiomyocytes caused by OAPA were reversed by EPA. EPA also retrieved a reduction in Cav1.2 L-type Ca2+ current, mRNA, and protein caused by OAPA. Immunocytochemical analysis revealed a distinct downregulation of the Cav1.2 channel caused by OAPA with a concomitant decrease in the phosphorylated component of a transcription factor adenosine-3',5'-cyclic monophosphate (cAMP) response element binding protein (CREB) in the nucleus, which were rescued by EPA. A free fatty acid receptor 4 (FFAR4) agonist TUG-891 reversed expression of Cav1.2 and CREB mRNA caused by OAPA, whereas an FFAR4 antagonist AH-7614 abolished the effects of EPA. Excessive reactive oxygen species (ROS) accumulation caused by OAPA decreased Cav1.2 and CREB mRNA expressions, which was reversed by an ROS scavenger. Our data suggest that EPA rescues cellular Cav1.2-Ca2+ channel decline caused by OAPA lipotoxicity and oxidative stresses via both free fatty acid receptor 4-dependent and -independent pathways.

15-epi-lipoxin A5 promotes neutrophil exit from exudates for clearance by splenic macrophages.

Specialized proresolving mediators (SPMs) promote local macrophage efferocytosis but excess leukocytes early in inflammation require additional leukocyte clearance mechanism for resolution. Here, neutrophil clearance mechanisms from localized acute inflammation were investigated in mouse dorsal air pouches. 15-HEPE (15-hydroxy-5Z,8Z,11Z,13E,17Z-eicosapentaenoic acid) levels were increased in the exudates. Activated human neutrophils converted 15-HEPE to lipoxin A5 (5S,6R,15S-trihydroxy-7E,9E,11Z,13E,17Z-eicosapentaenoic acid), 15-epi-lipoxin A5 (5S,6R,15R-trihydroxy-7E,9E,11Z,13E,17Z-eicosapentaenoic acid), and resolvin E4 (RvE4; 5S,15S-dihydroxy-6E,8Z,11Z,13E,17Z-eicosapentaenoic acid). Exogenous 15-epi-lipoxin A5, 15-epi-lipoxin A4 and a structural lipoxin mimetic significantly decreased exudate neutrophils and increased local tissue macrophage efferocytosis, with comparison to naproxen. 15-epi-lipoxin A5 also cleared exudate neutrophils faster than the apparent local capacity for stimulated macrophage efferocytosis, so the fate of exudate neutrophils was tracked with CD45.1 variant neutrophils. 15-epi-lipoxin A5 augmented the exit of adoptively transferred neutrophils from the pouch exudate to the spleen, and significantly increased splenic SIRPa+ and MARCO+ macrophage efferocytosis. Together, these findings demonstrate new systemic resolution mechanisms for 15-epi-lipoxin A5 and RvE4 in localized tissue inflammation, which distally engage the spleen to activate macrophage efferocytosis for the clearance of tissue exudate neutrophils.

Serum measures of docosahexaenoic acid (DHA) synthesis underestimates whole body DHA synthesis in male and female mice.

Females have higher docosahexaenoic acid (DHA) levels than males, proposed to be a result of higher DHA synthesis rates from α-linolenic acid (ALA). However, DHA synthesis rates are reported to be low, and have not been directly compared between sexes. Here, we apply a new compound specific isotope analysis model to determine n-3 PUFA synthesis rates in male and female mice and assess its potential translation to human populations. Male and female C57BL/6N mice were allocated to one of three 12-week dietary interventions with added ALA, eicosapentaenoic acid (EPA) or DHA. The diets included low carbon-13 (δ13C)-n-3 PUFA for four weeks, followed by high δ13C-n-3 PUFA for eight weeks (n=4 per diet, time point, sex). Following the diet switch, blood and tissues were collected at multiple time points, and fatty acid levels and δ13C were determined and fit to one-phase exponential decay modeling. Hepatic DHA synthesis rates were not different (P>.05) between sexes. However, n-3 docosapentaenoic acid (DPAn-3) synthesis from dietary EPA was 66% higher (P<.05) in males compared to females, suggesting higher synthesis downstream of DPAn-3 in females. Estimates of percent conversion of dietary ALA to serum DHA was 0.2%, in line with previous rodent and human estimates, but severely underestimates percent dietary ALA conversion to whole body DHA of 9.5%. Taken together, our data indicates that reports of low human DHA synthesis rates may be inaccurate, with synthesis being much higher than previously believed. Future animal studies and translation of this model to humans are needed for greater understanding of n-3 PUFA synthesis and metabolism, and whether the higher-than-expected ALA-derived DHA can offset dietary DHA recommendations set by health agencies.

Eicosapentaenoic Acid and the Outcomes in Older Patients Undergoing Atrial Fibrillation Ablation.

BACKGROUND: A lower serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio (EPA/AA) level correlates with cardiovascular events. Nevertheless, elevated serum EPA levels increase the risk of new-onset atrial fibrillation (AF) in older patients. The relationship between the EPA/AA and outcomes post-AF ablation remains unclear. This study investigated the impact of the EPA/AA on AF recurrence and cardiovascular events after AF ablation in older patients. METHODS AND RESULTS: This retrospective cohort study examined consecutive patients with AF aged ≥65 years who underwent a first-time AF ablation. We compared the 3-year AF recurrence and 5-year major adverse cardiovascular event (MACE) rates between patients divided into high and low EPA/AA levels defined as above and below the median EPA/AA value before ablation. MACE was defined as heart failure hospitalizations, strokes, coronary artery disease, major bleeding, and cardiovascular death. Among the 673 included patients, the median EPA/AA value was 0.35. Compared with the low EPA/AA group, the high EPA/AA group had a significantly higher cumulative incidence of AF recurrence (39.3% versus 27.6%; log-rank P=0.004) and lower cumulative incidence of MACE (13.8% versus 25.5%, log-rank P=0.021). A high EPA/AA level was determined as an independent predictor of AF recurrence (hazard ratio [HR], 1.75 95% CI, 1.24-2.49; P=0.002) and MACE (HR, 0.60 [95% CI, 0.36-0.99]; P=0.046). CONCLUSIONS: The EPA/AA was associated with AF recurrence and MACE after ablation in patients with AF aged ≥65 years.

Impact of Resolvin-E1 and Maresin-1 on Bone Marrow Stem Cell Osteogenesis under Inflammatory Stress.

Periodontal disease is characterized by inflammation and bone loss. Central to its pathogenesis is the dysregulated inflammatory response, complicating regenerative therapies. Mesenchymal stem cells (MSCs) hold significant promise in tissue repair and regeneration. This study investigated the effects of specialized pro-resolving mediators (SPMs), Resolvin E1 (RvE1) and Maresin 1 (MaR1), on the osteogenic differentiation of human bone marrow-derived MSCs under inflammatory conditions. The stem cells were treated with SPMs in the presence of lipopolysaccharide (LPS) to simulate an inflammatory environment. Osteogenic differentiation was assessed through alkaline phosphatase activity and alizarin red staining. Proteomic analysis was conducted to characterize the protein expression profile changes, focusing on proteins related to osteogenesis and osteoclastogenesis. Treatment with RvE1 and MaR1, both individually and in combination, significantly enhanced calcified deposit formation. Proteomic analysis revealed the differential expression of proteins associated with osteogenesis and osteoclastogenesis, highlighting the modulatory impact of SPMs on bone metabolism. RvE1 and MaR1 promote osteogenic differentiation of hBMMSCs in an inflammatory environment, with their combined application yielding synergistic effects. This study provides insights into the therapeutic potential of SPMs in enhancing bone regeneration, suggesting a promising avenue for developing regenerative therapies for periodontal disease and other conditions characterized by inflammation-induced bone loss.

Fatty acid desaturase insertion-deletion polymorphism rs66698963 predicts colorectal polyp prevention by the n-3 fatty acid eicosapentaenoic acid: a secondary analysis of the seAFOod polyp prevention trial.

BACKGROUND: A fatty acid desaturase (FADS) insertion-deletion (Indel) polymorphism (rs66698963) influences the expression of FADS1, which controls the synthesis of n-6 highly unsaturated fatty acid (HUFA) arachidonic acid (AA). The anti-inflammatory activity of the n-3 HUFA eicosapentaenoic acid (EPA) may be explained by competition with AA for proinflammatory lipid mediator synthesis. A precision medicine approach based on stratification by FADS Indel genotype could identify individuals, who benefit from greatest disease risk reduction by n-3 HUFAs. OBJECTIVES: We tested the hypothesis that the FADS insertion (I) allele predicts colorectal polyp risk reduction in a secondary analysis of the randomized, placebo-controlled, 2×2 factorial seAFOod polyp prevention trial of EPA 2000 mg daily and aspirin 300 mg daily for 12 mo (ISRCTN05926847). METHODS: Participant Indel genotype was determined by polymerase chain reaction (PCR) blind to trial outcomes. Colorectal polyp outcomes were included in negative binomial (polyp number) and logistic (polyp detection rate [PDR; percentage with one or more polyps]) regression models comparing each active intervention with its placebo. Presence of ≥1 Indel I allele and an interaction term (I allele × active intervention) were covariates. RESULTS: In 528 participants with colonoscopy and FADS Indel data, EPA use irrespective of Indel genotype, was not associated with reduced colorectal polyp number (incidence rate ratio [IRR]: 0.92; 95% confidence interval: 0.74, 1.16), mirroring original seAFOod trial analysis. However, the presence of ≥1 I allele identified EPA users with a significant reduction in colorectal polyp number (IRR: 0.50 [0.28, 0.90]), unlike aspirin, for which there was no interaction. Similar findings were obtained for the PDR. CONCLUSIONS: The FADS Indel I allele identified individuals, who displayed colorectal polyp prevention by EPA with a similar effect size to aspirin. Assessment of rs66698963 as a biomarker of therapeutic response to n-3 HUFAs in other populations and healthcare settings is warranted. The seAFOod polyp prevention trial and STOP-ADENOMA study were registered at International Standard Randomised Controlled Trial Number registry as ISRCTN05926847.

APOE genotype, eicosapentaenoic acid (EPA) supplementation and n-3 highly unsaturated fatty acid (HUFA) levels in patients with multiple colorectal polyps: A secondary analysis of the seAFOod polyp prevention trial.

INTRODUCTION: We examined the relationship between Apolipoprotein E (APOE) genotype and n-3 highly unsaturated fatty acid (HUFA) levels in participants of the seAFOod trial, who were undergoing colonoscopy surveillance after removal of colorectal polyps. METHODS: Baseline and on-treatment (eicosapentaenoic acid [EPA] 2 g daily or placebo for 6 months) levels of n-3 HUFAs, and plasma 18-hydroxyeicosapentaenoic acid (HEPE), were analysed according to APOE genotype (based on polymorphisms rs429358 and rs7412) in 584 participants. RESULTS: Before treatment, APOE2/2 individuals had lower levels, and APOE4/4 participants had higher levels, of n-3 HUFAs, including EPA, than APOE3/3 counterparts (P < 0.01 for the APOE2/2 versus APOE4/4 comparison). After EPA supplementation, n-3 HUFA levels were not significantly different when stratified by APOE genotype, although APOE4 carriers displayed lower plasma 18-HEPE levels than individuals without an APOE4 allele (P = 0.002). CONCLUSIONS: APOE genotype is associated with differential n-3 HUFA and 18-HEPE levels in individuals with multiple colorectal polyps.

The Effect of Eicosapentaenoic and Docosahexaenoic Acid Supplementation on Coronary Artery Calcium Progression in Subjects With Diabetes and Coronary Artery Disease: A Secondary Analysis of a Randomized Trial.

Higher coronary artery calcium (CAC) scores and progression of CAC are associated with higher mortality. We previously reported that subjects with coronary artery disease randomly allocated to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation or none had similar significant increases in CAC score over 30 months. Whether these findings are influenced by diabetes status is unknown. A total of 242 subjects with coronary artery disease who were on statin therapy were randomly allocated to to 1.86 g EPA and 1.5 g DHA daily or none (control). The CAC score was measured at baseline and 30-month follow-up using noncontrast, cardiac computed tomography. A significant interaction term between diabetes status and treatment arm was noted in the prediction of the CAC score (p <0.001). A total of 176 subjects (85.8% men) had no diabetes and 66 subjects (80.3% men) had diabetes. The mean age was 62.9 ± 7.9 versus 63.2 ± 7.1 years, respectively. The mean low-density lipoprotein cholesterol and median triglyceride levels were not significantly different between those without and with diabetes: 77.7 ± 25.9 versus 77.1 ± 30.2 mg/100 ml, respectively, and 117.0 (78.0 to 158.0) versus 119.0 (84.5 to 201.5) mg/100 ml, respectively. Subjects with diabetes on EPA+DHA had a greater increase in CAC score than subjects with diabetes in the control group (median 380.7 vs 183.5, respectively, p = 0.021). In contrast, no difference occurred between the EPA+DHA and control groups in subjects without diabetes (175.7 vs 201.1, respectively, p = 0.41). In conclusion, EPA+DHA supplementation was associated with greater CAC progression in subjects with diabetes than subjects with diabetes in the control group over a 30-month period; whether this indicates progression of the disease burden or plaque stabilization requires further study.