Background and Objectives: Pruritus is a common and disabling symptom affecting as much as 50-90% of chronic kidney disease (CKD) patients undergoing dialysis. The pruritus experienced by these patients is often resistant to common anti-pruritic agents and has an overall negative impact on quality of life. With its antioxidant property and anti-inflammatory effects, omega-3 fatty acids have been used to alleviate pruritus. The objective of this study is to assess the effect of omega-3 fatty acid supplementation in reducing the severity of pruritus among dialytic CKD patients. Methods: Various electronic databases were searched from inception to August 2022. Randomized controlled trials comparing the effect of omega-3 fatty acids versus placebo on the pruritus scores were included. The studies were independently assessed by three reviewers. Revman version 5.4 was used to analyze the data extracted from the studies while heterogeneity was evaluated using Chi2 and I2. Results: A total of four studies with a population of 166 patients were included in the meta-analysis. The results show an overall beneficial effect of omega-3 fatty acids with a standardized mean difference of -1.40 (CI -1.74 to -1.05, Z=7.95, p value <0.00001). With a Chi2 of 2.91 (p=0.41) and I2 of 0%, there was no significant heterogeneity observed in the pooled analysis. Conclusion Overall, the results of the meta-analysis support the finding that omega-3 fatty acid supplementation may have a beneficial effect on reducing the severity of pruritus among CKD patients on dialysis.
Fatty Acids, Omega-3 ; Renal Insufficiency, Chronic ; Pruritus

Essential fatty acids are those that could not be synthesized by the body itself but crucial for health and life. Studies have shown that ω-3 fatty acids may facilitate human physiological functions. Mammals lack ω-3 desaturase gene, and the Δ15 fatty acid desaturase (Δ15 Des) from Caenorhabditis elegans can transform the ω-6 polyunsaturated fatty acids (PUFAs) into ω-3 PUFAs. Transgenic mice expressing Δ15 Des enzyme activity was constructed by using a PiggyBac transposon (PB). Homozygous transgenic mice with stable inheritance was bred in a short time, with a positive rate of 35.1% achieved. The mice were fed with 6% ω-6 PUFAs and the changes of fatty acids in mice were detected by gas chromatography (GC). The expression level of Δ15 Des in mice was detected by quantitative PCR (qPCR) and Western blotting (WB). qPCR and GC analysis revealed that the percentage of positive mice harboring the active gene was 61.53%. Compared with traditional methods, the transformation efficiency and activity of Δ15 Des were significantly improved, and homozygotes showed higher activity than that of heterozygotes. This further verified the efficient transduction efficiency of the PiggyBac transposon system.
Animals ; Caenorhabditis elegans/genetics* ; Fatty Acid Desaturases/genetics* ; Fatty Acids ; Fatty Acids, Omega-3 ; Mice ; Mice, Transgenic

The fatty acid composition of spermatozoa has been shown to be important for their function, and L-carnitine is crucial for fatty acid metabolism. Its levels in the seminal plasma positively correlate with semen quality, whereas high body mass index (BMI) is associated with both reduced semen quality and altered sperm fatty acid composition. Here, we examined the associations between free seminal L-carnitine levels and sperm fatty acid composition as well as BMI. Semen samples were collected and analyzed from 128 men with unknown fertility status and with BMI ranging from 19 kg m^-2 to 63 kg m^-2. Sperm fatty acid composition was assessed by gas chromatography, while free seminal L-carnitine analysis was performed using high-performance liquid chromatography. Multiple linear regression analysis showed a positive correlation of free seminal L-carnitine levels with the amount of sperm palmitic acid (β = 0.21; P = 0.014), docosahexaenoic acid (DHA; β = 0.23; P = 0.007), and total n-3 polyunsaturated fatty acids (β = 0.23; P = 0.008) and a negative correlation of free seminal L-carnitine levels with lignoceric acid (β = -0.29; P = 0.001) and total n-6 polyunsaturated fatty acids (β = -0.24; P = 0.012) when adjusted for covariates. There was no relationship between free seminal L-carnitine levels and BMI. Since free seminal L-carnitine levels are associated with semen quality, the absence of a correlation with BMI suggests that reduced semen quality in obese men is independent of seminal L-carnitine.
Carnitine ; Docosahexaenoic Acids ; Fatty Acids ; Humans ; Male ; Semen ; Semen Analysis ; Sperm Count ; Sperm Motility ; Spermatozoa

Resolution of inflammation plays an important part in maintaining homeostasis. It is an actively programmed progress involving multiple immune cells and mediators. Specialized pro-resolving mediators (SPMs) derived from Ω-3 polyunsaturated fatty acids include resolvins, protectins and maresins, and they exert abilities in the resolution of inflammation, host defense, organ protection, and tissue generation. Periodontitis is an inflammatory and destructive disease in the periodontal tissue initiated by dental plaque. Inadequate proinflammatory or proresolving responses, or the imbalance between the two, may contribute to the pathogenesis of the disease. Studies have shown that activating specialized receptors SPMs displayed multiple biological effects towards periodontitis, including resolution of inflammation, alveolar bone protection, periodontal tissue regeneration, and pathogen resistance. Thus, the relationship between SPM and periodontitis and the potentials and challenges in SPM application were reviewed.
Fatty Acids, Omega-3 ; Homeostasis ; Humans ; Inflammation ; Inflammation Mediators ; Periodontitis

Adequate supply of long-chain polyunsaturated fatty acids (LCPUFAs) is of great importance for neonates, especially preterm infants. In particular,
Fatty Acids ; Fatty Acids, Omega-3 ; Fatty Acids, Unsaturated ; Humans ; Infant ; Infant, Newborn ; Infant, Premature

Nonalcoholic fatty liver disease (NAFLD) and hyperhomocysteinemia (HHcy) both are major health problems worldwide, whose incidence are closely related with each other. We previously reported the mechanism of HHcy-caused hepatic steatosis, but the role of n-3 polyunsaturated fatty acid (n-3 PUFA) in HHcy-induced hepatic steatosis remains unclear. In this study, 6-week-old C57BL/6 male mice were given a high methionine diet (HMD, 2% methionine diet), and plasma homocysteine levels were measured by ELISA to confirm the establishment of an HHcy model. Meantime, mice were fed HMD with or without n-3 PUFA supplement for 8 weeks to determine the role and mechanism of n-3 PUFA in hepatic steatosis induced by HHcy. Results showed that n-3 PUFA significantly improved hepatic lipid deposition induced by HHcy. qRT-PCR analysis demonstrated that n-3 PUFA inhibited the upregulation of Cd36, a key enzyme of fatty acid uptake, caused by HHcy. Further, the inhibition of hepatic Cd36 expression was associated with the inactivation of aryl hydrocarbon receptor (Ahr) induced by n-3 PUFA. Of note, mass spectrometry revealed that hepatic content of lipoxin A
Animals ; Fatty Acids, Omega-3 ; Fatty Liver/drug therapy* ; Hyperhomocysteinemia/drug therapy* ; Liver ; Male ; Mice ; Mice, Inbred C57BL

Type 2 diabetes mellitus (T2DM) is recognized as one of the most prevalent metabolic diseases, and it is mostly associated with oxidative stress, atherosclerosis and dyslipidemia. Paraoxonase 2 (PON2) due to its antioxidant properties may play a role in the atherosclerosis development. Although long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) have been shown to reduce the risk of cardiovascular disease, the exact mechanism of action is still unknown. Our goal in this study was to determine the effect of EPA administration on gene expression of PON2 in patients with T2DM. Present study was a randomized, controlled double-blind trial. Thirty-six patients with T2DM were randomly allocated to receive 2 g/day EPA (n = 18) or placebo (n = 18) for 8 weeks. There were no significant differences between 2 groups concerning demographic or biochemical variables, and dietary intakes as well (p > 0.05). However, patients received EPA showed a significant increase in the gene expression of PON2 compared with placebo group (p = 0.027). In addition, high-density lipoprotein cholesterol increased and fasting blood sugar decreased significantly after EPA supplementation compared with control group. Taken together, supplementation with 2 g/day EPA could be atheroprotective via the upregulation of PON2 in patients with T2DM. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03258840
Aryldialkylphosphatase* ; Atherosclerosis ; Blood Glucose ; Cardiovascular Diseases ; Cholesterol ; Diabetes Mellitus, Type 2* ; Dyslipidemias ; Eicosapentaenoic Acid* ; Fasting ; Fatty Acids, Unsaturated ; Gene Expression* ; Humans ; Lipoproteins ; Metabolic Diseases ; Oxidative Stress ; Up-Regulation

Docosahexaenoic acid (DHA) has many unique physiological functions such as promoting the development of brain and retina in infants. Therefore, it is widely applied to food, pharmacy, breeding and other industries. To obtain engineered strains of Aurantiochytrium limacinum SR21 suitable for industrial application with increased lipid and DHA production, we designed a simple, fast, accurate and high-throughput screening method based on Nile red staining of oil droplets. First, ultraviolet C (UVC) mutagenesis was used to generate a random mutant library of A. limacinum. Second, screening conditions were optimized including staining conditions of Nile red and the sorting criterion. Thereby, three putative high-lipid mutants (D03432, D05106 and D01521) were selected from the mutant library containing 3 648 mutated clones. The three mutants grew faster and produced higher amounts of lipids and DHA compared to wild type (WT). In 100 mL cultures, the lipid content of D03432 and D05106 mutants reached 64.74% and 63.13% of dry cell weight respectively, whereas the wild strain exhibited only 43.19%. DHA yield in these two mutants were even 2.26-fold and 2.37-fold higher than that of the wild strain. Experiment with 5 L fermentor further confirmed that D03432 and D05106 mutants had better performance than the wild strain on DHA yield (45.51% and 66.46% more than that of the wild strain, respectively), and demonstrated their high potential for industrial application. This work not only generated several high-DHA content mutants with high potential for industrial use, but also provided vital guidance for high-throughput screening of lipid hyper-accumulating mutants in other oil-producing microorganisms.
Bioreactors ; Docosahexaenoic Acids ; Mutagenesis ; Staining and Labeling ; Stramenopiles

BACKGROUND/OBJECTIVES: Adequate dietary fatty acid intake is important for toddlers between 12–24 months of age, as this is a period of dietary transition in conjunction with rapid growth and development; however, actual fatty acid intake during this period seldom has been explored. This study was conducted to assess the intake status of n-3 and n-6 polyunsaturated fatty acids by toddlers during the 12–24-month period using 2010–2015 Korea National Health and Nutrition Examination Survey data. SUBJECTS/METHODS: Twenty-four-hour dietary recall data of 12–24-month-old toddlers (n = 544) was used to estimate the intakes of α-linolenic acid (ALA; 18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3), linoleic acid (LA; 18:2n-6), and arachidonic acid (AA; 20:4n-6), as well as the major dietary sources of each. The results were compared with the expected intake for exclusively breastfed infants in the first 6 months of life and available dietary recommendations. RESULTS: Mean daily intakes of ALA, EPA, DHA, LA, and AA were 529.9, 22.4, 37.0, 3907.6, and 20.0 mg/day, respectively. Dietary intakes of these fatty acids fell below the expected intake for 0–5-month-old exclusively breastfed infants. In particular, DHA and AA intakes were 4 to 5 times lower. The dietary assessment indicated that the mean intake of essential fatty acids ALA and LA was below the European and the FAO/WHO dietary recommendations, particularly for DHA, which was approximately 30% and 14–16% lower, respectively. The key sources of the essential fatty acids, DHA, and AA were soy (28.2%), fish (97.3%), and animals (53.7%), respectively. CONCLUSIONS: Considering the prevailing view of DHA and AA requirements on early brain development, there remains considerable room for improvement in their intakes in the diets of Korean toddlers. Further studies are warranted to explore how increasing dietary intakes of DHA and AA could benefit brain development during infancy and early childhood.
Animals ; Arachidonic Acid ; Brain ; Diet ; Eicosapentaenoic Acid ; Fatty Acids ; Fatty Acids, Essential ; Fatty Acids, Unsaturated ; Growth and Development ; Humans ; Infant ; Korea ; Linoleic Acid ; Nutrition Surveys

BACKGROUND/OBJECTIVES: Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of α-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha (PPARα). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by PPARα. MATERIALS/METHODS: The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among PPARα homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate (PPARα agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA. RESULTS: PPARα ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, PPARα activation increased hepatic Acox, Fads1, Fads2 and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex. CONCLUSIONS: LCPUFA enzyme expression was altered by PPARα. Either PPARα deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.
Animals ; Brain ; Brain-Derived Neurotrophic Factor ; Clofibrate ; Docosahexaenoic Acids ; Fatty Acid Desaturases ; Liver ; Mice ; Peroxisomes ; PPAR alpha ; Retina ; RNA, Messenger