Long-chain PUFA ameliorate enterotoxigenic Escherichia coli-induced intestinal inflammation and cell injury by modulating pyroptosis and necroptosis signaling pathways in porcine intestinal epithelial cells

This study was aimed to investigate whether EPA and arachidonic acid (ARA), the representative n-3 or n-6 PUFA, could alleviate enterotoxigenic Escherichia coli (ETEC) K88-induced inflammation and injury of intestinal porcine epithelial cells 1 (IPEC-1) by modulating pyroptosis and necroptosis signalling pathways. IPEC-1 cells were cultured with or without EPA or ARA in the presence or absence of ETEC K88. EPA and ARA reduced ETEC K88 adhesion and endotoxin content in the supernatant. EPA and ARA increased transepithelial electrical resistance, decreased permeability of fluorescein isothiocyanate-labelled dextran, increased membrane protein expression of occludin, ZO-1 and claudin-1 and relieved disturbed distribution of these proteins. EPA and ARA also reduced cell necrosis ratio. EPA or ARA reduced mRNA and concentration of TNF-α, IL-6 and IL-8 and decreased mRNA abundances of intestinal toll-like receptors 4 and its downstream signals. Moreover, EPA and ARA downregulated mRNA expression of nod-like receptor protein 3 (NLRP3), caspase 1 and IL-18 and inhibited protein expression of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), gasdermin D and caspase-1. Finally, EPA and ARA reduced mRNA expression of fas-associated death domain protein, caspase 8, receptor-interacting protein kinase (RIP) 1, mixed lineage kinase-like protein (MLKL), phosphoglycerate mutase 5 (PGAM5), motility-related protein 1 (Drp1) and high mobility protein 1 (HMGB1) and inhibited protein expression of phosphorylated-RIP1, p-RIP3, p-MLKL and HMGB1. These data demonstrate that EPA and ARA prevent ETEC K88-induced cell inflammation and injury, which is partly through inhibiting pyroptosis and necroptosis signalling pathways.

Association between FADS1 rs174547 and levels of long-chain PUFA: a meta-analysis

In the present study, we analysed the effects of SNP rs174547 (T/C) in the fatty acid desaturase 1 (FADS1) gene on long-chain PUFA levels. Four databases were searched to retrieve related literature with keywords such as fatty acid (FA), SNP, FADS1 and rs174547. A meta-analysis of the data was performed using Stata12.0 software, including summary statistics, test for heterogeneity, evaluation of publication bias, subgroup analysis and sensitivity analysis. The associations between rs174547 in FADS1 and seven types of FA, and Δ-5 (D5D) and Δ-6 fatty acid desaturase (D6D) activity were assessed based on the pooled results from eleven papers. A total of 3713 individuals (1529 TT and 2184 TC + CC) were included. The results demonstrated that minor C allele carriers of rs174547 had higher linoleic acid (LA; P < 0·001) and α-linolenic acid (P = 0·020) levels, lower γ-linolenic acid (GLA; P = 0·001) and arachidonic acid (P = 0·024) levels, and lower D5D (P = 0·005) and D6D (P = 0·004) activities than the TT genotype group. Stratification analysis showed that minor C allele carriers of rs174547 had higher LA and lower GLA levels and lower D6D activities in plasma (LA, P < 0·001; GLA, P < 0·001; D6D activity, P < 0·001) samples and in Asian populations (LA, P < 0·001; GLA, P = 0·001; D6D activity, P = 0·001) than the TT genotype group. In conclusion, minor C allele carriers of the SNP rs174547 were associated with decreased activity of D5D and D6D.

The importance of phospholipids combined with long-chain PUFA in formulated diets for pikeperch (Sander lucioperca) larvae

Dietary phosphoglycerides and n-3 long-chain PUFA (LC-PUFA) play important functions in the development of pikeperch (Sander lucioperca) larvae. This study aimed to determine optimal dietary levels of soyabean lecithin (SBL)-derived phospholipids (PL) in starter feeds for pikeperch larvae 10-30 d post-hatch (DPH) and examine performance and ontogeny by additional supplementation of n-3 LC-PUFA in the form of Algatrium DHA 70 (glyceride product; 660-700 mg/g DHA; EPA 60-75 mg/g). In total, six isoproteic and isoenergetic extruded diets were formulated with increasing levels of PL (3·7, 8·3 or 14·5 % wet weight (w.w.), respectively); however, three of the diets were supplemented with three levels of Algatrium DHA 70 (0·6, 2·0 or 3·4 %, respectively). Liver proteomic analyses of larvae at 30 DPH were included for effects of PL and primarily DHA on performance, physiological expression and interactions in larval proteins. In addition, bone anomalies, digestive enzymatic activity, candidate gene expression and skeleton morphogenesis were examined. Results confirmed the importance of dietary PL levels of at least 8·2 % w.w., and an additional beneficiary effect of supplementation with DHA plus EPA. Thus, combined supplementation of SBL (up to 14·51 % w.w. PL) and n-3 LC-PUFA (1·004 % DM DHA and 0·169 % DM EPA) in the form of TAG resulted in highest growth and lowest incidence of anomalies, improved digestive enzyme activity and had differential effect on liver proteomics. The results denote that essential fatty acids can be supplemented as TAG to have beneficial effects in pikeperch larvae development.

Quantity and species of fish consumed shape breast-milk fatty acid concentrations around Lake Victoria, Kenya

OBJECTIVE

Long-chain PUFA (LCPUFA) found in breast milk are derived from dietary sources and critical for optimal infant development. We examined associations between fish consumption and concentrations of LCPUFA and essential n-3 and n-6 fatty acids in breast milk among mothers living around Lake Victoria.

DESIGN

We used cross-sectional analyses of associations between recent fish consumption and breast-milk fatty acid concentrations.

SETTING

The study was conducted around Lake Victoria on Mfangano Island, Kenya, where multiple fish species are key dietary components and also are widely exported.

SUBJECTS

Breast-feeding mothers (n 60) provided breast-milk samples, anthropometric measurements and questionnaire responses.

RESULTS

In the previous 3 d, 97 % of women consumed a mean of 178 (sd 111) g fish (~2 servings/3 d). Mean breast-milk concentrations included DHA (0·75 % of total fatty acids), EPA (0·16 %), α-linolenic acid (ALA; 0·54 %), arachidonic acid (AA; 0·44 %) and linoleic acid (LA; 12·7 %). Breast-milk DHA concentrations exceeded the global average of 0·32 % in fifty-nine of sixty samples. We found native cichlids (Cichlidae) and dagaa (Rastrineobola argentea) contributed high levels of DHA, EPA and AA to local diets. We also found evidence for associations between fish species consumed and breast-milk LCPUFA concentrations when controlling for intake of other fish species, maternal body mass, maternal age, child age and exclusive breast-feeding.

CONCLUSIONS

The fatty acid composition of breast milk was influenced by the fish species consumed. Ensuring access to diverse fish and particularly inexpensive, locally available species, may be important for diet quality as well as infant growth and development.

Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months

Breast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants' blood T-cell profiles and ex vivo-produced cytokines after anti-CD3/CD28 stimulation of peripheral blood mononuclear cells in 6-month-old infants from the Copenhagen Prospective Study of Asthma in Childhood birth cohort. LCPUFA concentrations of breast milk were assessed at 4 weeks of age, and FADS SNP were determined in both mothers and infants (n 109). In general, breast milk arachidonic acid (AA) levels were inversely correlated with the production of IL-10 (r -0.25; P=0.004), IL-17 (r -0.24; P=0.005), IL-5 (r -0.21; P=0.014) and IL-13 (r -0.17; P=0.047), whereas EPA was positively correlated with the counts of blood regulatory T-cells and cytotoxic T-cells and decreased T-helper cell counts. The minor FADS alleles were associated with lower breast milk AA and EPA, and infants of mothers carrying the minor allele of FADS SNP rs174556 had higher production of IL-10 (r -0.23; P=0.018), IL-17 (r -0.25; P=0.009) and IL-5 (r -0.21; P=0.038) from ex vivo-activated immune cells. We observed no association between T-cell distribution and maternal or infant FADS gene variants. We conclude that increased maternal LCPUFA synthesis and breast milk AA are associated with decreased levels of IL-5, IL-13 (type-2 related), IL-17 (type-17 related) and IL-10 (regulatory immune responses), but not with interferon-γ and TNF-α, which could be due to an effect of the maternal FADS variants on the offspring immune response transferred via breast milk LCPUFA.

Maternal long-chain PUFA supplementation during protein deficiency improves brain fatty acid accretion in rat pups by altering the milk fatty acid composition of the dam

Long-chain PUFA (LC-PUFA) are important for fetal and neonatal brain development. However, their accretion in the brain is compromised during maternal protein restriction. Hence, we investigated the effect of maternal supplementation with n-3 DHA plus n-6 arachidonic acid (ARA) at a low protein level (9 %) on offspring brain fatty acid accretion using Wistar rats (nine rats per group) randomly fed a control (C), a low-protein (LP) or a low-protein DHA + ARA-supplemented (LPS) diet during gestation and lactation. At birth, pups from the LPS group had the highest brain DHA and n-3 fatty acid levels (P = 0·001), whereas pups from the LP group had the highest MUFA (P = 0·05) but the lowest DHA and total n-3 PUFA levels (P = 0·000). During lactation, pups from the LPS group accrued significantly more α-linolenic acid (P = 0·003), EPA (P = 0·02) and DHA (P = 0·000) in brain lipids than pups from the LP group, whereas brain lipids of pups from the LP group had markedly increased levels of the n-3 deficiency marker docosapentaenoic acid and n-6:n-3 ratio (P = 0·000). Owing to supplementation, milk from LPS dams had the highest DHA and ARA, but lower SCFA and medium-chain fatty acids as compared with milk from C and LP dams during early lactation, but normalised by mid-lactation. To conclude, adverse effects of restricted maternal protein intake on LC-PUFA accretion in the brain of offspring were ameliorated by alterations in maternal milk fatty acid profile due to supplementation. Results underscore the importance of LC-PUFA for protein-deficient mothers during gestation as well as lactation to achieve the optimum brain LC-PUFA status of progeny.