ω-6 PUFA rich diets resulted in increased translocation of microbes from Enterobacteriacea across the intestinal mucosae.

<p>A) Colonic tissue sections were hybridized with a γ-Proteobacteria probe (green) and the nuclei stained with DAPI (blue) to examine the locations of Enterobacteriaceae. These Gram-negative microbes were found in the submucosae (600× magnification scale bar = 14.2 µm) prior to infection in the colons of mice fed ω-6 PUFA rich diets. During infection with <i>C. rodentium</i>, a member of Enterobacteriaceae, the pathogen was found deep into the crypts (100× magnification, scale bar = 85.4 µm; upper panel) and in the submucosae (600× magnification scale bar = 14.2 µm) in the colons of mice fed ω-6 PUFA rich diets. B) Colony forming units (CFU) recovered from the spleen and mesenteric lymph nodes (MLN) were highest from mice fed ω-6 PUFA rich diets after 10 days of <i>C. rodentium</i> infection. CFU were enumerated from tissues removed from mice fed various diets and were homogenized followed by plating in serial dilutions on Lb agar. (*, <i>P</i><0.05).</p

Major fatty acid compositions of dietary oil used in preparing high-fat diets.

<p>Major fatty acid compositions of dietary oil used in preparing high-fat diets.</p

While ω-6 PUFA rich diets resulted in the induction of LPS binding protein prior to infection, it was the ω-3 PUFA supplemented diet that induced infection-induced septic responses.

<p>LPS binding protein, TNF-α and IL-15 were measured in sera from in mice that had been fed the various diets both before and after infection with <i>C. rodentium</i>. (*, <i>P</i><0.05).</p

Composition of high-fat diets.

1<p>Mineral mix (mg/g): di calcium phosphate 500, magnesium oxide 24; potassium citrate 220, potassium sulfate 52; sodium chloride 74, chromium KSO₄ 12H₂0 0.55; cupric carbonate 0.3, potassium iodate 0.01; ferric citrate 6, manganous carbonate 3.5, sodium selenite 0.01, zinc carbonate 1.6; sucrose 118.03.</p>2<p>Vitamin Mix (mg/g): vitamin A 0.8; vitamin D₃ 1; vitamin E 10; menadione sodium bisulfite 0.08; nicotinic acid 3; calcium pantothenate 1.6; pyridoxine HCl 0.7; riboflavin 0.6; thiamin 0.6; sucrose 978.42.</p>3<p>Added to meet essential fatty acid requirements for all groups.</p

ω-3 PUFA supplementation to ω-6 PUFA rich diets resulted in impaired infection-induced intestinal alkaline phosphatase activity.

<p>A) IAP+ cells were highest in ω-6 PUFA rich diet groups during infection and ω-3 PUFA supplementation impaired this response. Colon sections were stained for the presence of IAP+ cells and quantified. Representative immunofluorescence images are shown at 200× magnification (scale bar = 13.6 µm). B) While both the low and high ω-6 PUFA rich diet groups showed an induction of LPS-dephosphorylating activity during infection induced colitis, theω-3 PUFA supplementation fed mice were unable to dephosphorylate LPS in response to infection. Colonic tissues were homogenized, supernatant collected and LPS incubated with each diet group for 2 hours. A colorimetric malachite green solution was used to measure absorbance at 620 nm and the LPS-dephosphorylating activity/mg of protein was determined for each diet group. (*, <i>P</i><0.05; **, <i>P</i><0.005).</p

ω-3 PUFA supplementation to ω-6 PUFA rich diets impairs intestinal inflammatory cell infiltration during <i>C. rodentium-</i>induced colitis.

<p>While ω-6 PUFA rich diets induced the infiltration of macrophages, neutrophils and PGE2 inflammatory cells, ω-3 PUFA supplementation prevented the enhanced infiltration during infection. Colon sections were stained for the presence of submucosal A) F4/80+ macrophages B) MPO+ neutrophils and C) PGE2+ cells and quantified. Representative immunofluorescence images are shown at 200× magnification. (scale bar = 13.6 µm; *, <i>P</i><0.05).</p

While ω-3 PUFA supplementation prevents ω-6 PUFA induced histopathologic severity, these mice suffered increased mortality and morbidity during <i>C. rodentium</i> infection.

<p>A) C57BL/6 mice fed ω-6 PUFA rich diets supplemented with ω-3 PUFA suffered increased mortality during infection with <i>C. rodentium</i>. 30% of mice fed ω-3 PUFA required euthanization by 6–8 days p.i., in contrast to the low or high-fat ω-6 PUFA groups. B) While both low or high-fat ω-6 PUFA diets result in similar weight changes during infection with <i>C. rodentium</i>, the ω-3 PUFA supplemented group suffered significantly increased cachexia throughout days 5–10 p.i. C) Mice fed ω-6 PUFA rich diets had the highest induction of histopathologic severity during <i>C. rodentium</i>-induced colitis while ω-3 PUFA supplementation reduced this. D) Representative colon sections from diet groups were taken at 100× magnification and stitched together using Metamorph software (black scale bar = 46.5 µm) or 200× magnification (white scale bar = 20.7 µm). E) Colonic tissue sections were stained for TUNEL-positive cells. Colons from mice fed low and high-fat ω-6 PUFA diets showed increased cell death compared to mice fed diets supplemented with ω-3 PUFA. (*, <i>P</i><0.05).</p

ω-6 PUFA rich diets induce dysbiosis and ω-3 PUFA supplementation reverses these blooms while enriching beneficial microbes.

<p>A) ω-6 PUFA rich diets promote a microbiota enriched with Enterobacteriacea, Segmented Filamentous Bacteria (SFB) and microbes from the <i>Clostridia coccoides</i> group and ω-3 supplementation reverses this and B) enriches <i>Bifidobacteria</i> spp., <i>Lactobacillus</i> spp. and <i>Enterococcus faecium</i>. C) High-fat diet groups resulted in decreased <i>Bacteroides</i> spp. and <i>Enterococcus faecalis</i>. Expression is relative to the low ω-6 PUFA group. (*, <i>P</i><0.05).</p

ω-3 PUFA supplementation to ω-6 PUFA rich diets impairs infection-induced cytokine and chemokine responses.

<p>qPCR analysis of colonic tissues revealed that both high and low ω-6 PUFA diets were relatively similar where infection induced cytokine and the chemokine Relm-β responses. However, the ω-3 PUFA supplemented diet had impaired IFN-γ, TNF-α, IL-17A, IL-22 and IL-23, as well as the Relm-β responses evident by the lack of their induction during infection. (*, <i>P</i><0.05; **, <i>P</i><0.005).</p

Short Term Exercise Induces PGC-1α, Ameliorates Inflammation and Increases Mitochondrial Membrane Proteins but Fails to Increase Respiratory Enzymes in Aging Diabetic Hearts

<div><p>PGC-1α, a transcriptional coactivator, controls inflammation and mitochondrial gene expression in insulin-sensitive tissues following exercise intervention. However, attributing such effects to PGC-1α is counfounded by exercise-induced fluctuations in blood glucose, insulin or bodyweight in diabetic patients. The goal of this study was to investigate the role of PGC-1α on inflammation and mitochondrial protein expressions in aging <i>db/db</i> mice hearts, independent of changes in glycemic parameters. In 8-month-old <i>db/db</i> mice hearts with diabetes lasting over 22 weeks, short-term, moderate-intensity exercise upregulated PGC-1α without altering body weight or glycemic parameters. Nonetheless, such a regimen lowered both cardiac (macrophage infiltration, iNOS and TNFα) and systemic (circulating chemokines and cytokines) inflammation. Curiously, such an anti-inflammatory effect was also linked to attenuated expression of downstream transcription factors of PGC-1α such as NRF-1 and several respiratory genes. Such mismatch between PGC-1α and its downstream targets was associated with elevated mitochondrial membrane proteins like Tom70 but a concurrent reduction in oxidative phosphorylation protein expressions in exercised <i>db/db</i> hearts. As mitochondrial oxidative stress was predominant in these hearts, in support of our <i>in vivo</i> data, increasing concentrations of H₂O₂ dose-dependently increased PGC-1α expression while inhibiting expression of inflammatory genes and downstream transcription factors in H9c2 cardiomyocytes <i>in vitro</i>. We conclude that short-term exercise-induced oxidative stress may be key in attenuating cardiac inflammatory genes and impairing PGC-1α mediated gene transcription of downstream transcription factors in type 2 diabetic hearts at an advanced age.</p></div