Fish Oil Enhances Intestinal Integrity and Inhibits TLR4 and NOD2 Signaling Pathways in Weaned Pigs after LPS Challenge3

Abstract

Long-chain (n-3) PUFA exert beneficial effects on inflammatory bowel diseases in animal models and clinical trials. In addition, pattern recognition receptors such as toll-like receptors (TLR) and nucleotide-binding oligomerization domain proteins (NOD) play a critical role in intestinal inflammation. We hypothesized that fish oil could alleviate Escherichia coli LPS-induced intestinal injury via modulation of TLR4 and NOD signaling pathways. Twenty-four weaned piglets were used in a 2 × 2 factorial design and the main factors included a dietary treatment (5% corn oil or 5% fish oil) and immunological challenge (LPS or saline). After feeding fish oil or corn oil diets for 21 d, pigs were injected with LPS or saline. At 4 h postinjection, blood samples were collected and pigs were killed. EPA, DHA, and total (n-3) PUFA were enriched in intestinal mucosa through fish supplementation. Fish oil improved intestinal morphology, indicated by greater villus height and villus height:crypt depth ratio, and intestinal barrier function, indicated by decreased plasma diamine oxidase (DAO) activity and increased mucosal DAO activity as well as enhanced protein expression of intestinal tight junction proteins including occludin and claudin-1. Moreover, fish oil decreased intestinal TNFα and PGE(2) concentrations and caspase-3 and heat shock protein 70 protein expression. Finally, fish oil downregulated the mRNA expression of intestinal TLR4 and its downstream signals myeloid differentiation factor 88, IL-1 receptor-associated kinase 1, TNFα receptor-associated factor 6, and NOD2, and its adaptor molecule, receptor-interacting serine/threonine-protein kinase 2. Fish oil decreased the protein expression of intestinal NFκB p65. These results indicate that fish oil supplementation is associated with inhibition of TLR4 and NOD2 signaling pathways and concomitant improvement of intestinal integrity under an inflammatory condition.

Glycine enhances muscle protein mass associated with maintaining Akt-mTOR-FOXO1 signaling and suppressing TLR4 and NOD2 signaling in piglets challenged with LPS

“…After receiving the control, 1.0% glycine and 2.0% glycine-supplemented diets for 28 days, the pigs were given an intraperitoneal injection of LPS at 100 g/kg BW or the same volume of 0.9% NaCl solution. The LPS dose was used according to our previous studies (25,28,29), which demonstrated that this dose of LPS caused acute tissue injury in weaned pigs. After administration with LPS or 0.9% NaCl solution, all piglets were deprived of feed until slaughter to avoid the potential effects of LPS-caused feed intake reduction on variables in blood and muscle.…”

“…Total RNA extraction, quantification, reverse transcription, and real-time quantitative PCR were conducted according to the method as previously described (28). Briefly, total RNA was extracted from muscle samples with the TRIzol reagent (No.…”

“…Protein immunoblot analysis was carried out according to the method described previously (28). Briefly, the muscle samples (150 -200 mg) were homogenized in 600 l of lysis buffer with protease inhibitors included and centrifuged at 12,000 g for 15 min at 4°C to collect supernatants.…”

N-3 PUFAs and neuroinflammatory processes in cognitive disorders

“…Both in vivo and in vitro studies have reported antiinflammatory activities of DHA in the brain especially in microglia (Laye, 2010;Orr and Bazinet, 2008). At the cellular level, brain DHA modulates several proinflammatory signalling pathways in microglia such as TLR signalling and nucleotide-binding oligomerization domain protein (NOD) signalling (De Smedt-Peyrusse et al, 2008;Liu et al, 2012), inhibits JUNK , and reduces or blocks NF-kB signalling (De Smedt-Peyrusse et al, 2008;Orr et al, 2013). The inhibitory effect of DHA on proinflammatory signalling pathway could be mediated by both non-genomic and genomic effect.…”

Sensibilidade periférica à insulina e resposta inflamatória na vigência de dietas obesogênicas, suplementação com óleo de peixe e ausência de TLR-4.

“…Ocorre aumento da altura das vilosidades e melhora a função da barreira intestinal indicada pela diminuição da atividade da diamina oxidase no plasma e aumento da expressão de proteínas tight-junction como ocludina e claudina-1 no epitélio intestinal (LIU et al, 2012 Além disso, permitirá o desenvolvimento de novas terapias anti-obesogênicas que têm como alvo vias intracelulares envolvidas no processo inflamatório dos tecidos responsivos à insulina, como fígado e tecido adiposo, e ateroscleróticos, como a aorta torácica e a gordura perivascular.…”