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Western diet enhances hepatic inflammation in mice exposed to cecal ligation and puncture.

Rivera CA, Gaskin L, Singer G, Houghton J, Allman M - BMC Physiol. (2010)

Bottom Line: Therefore, we hypothesized that the combined effects of sepsis and feeding WD on TRL-4 signaling would exacerbate hepatic inflammation.To demonstrate the direct effect of saturated fatty acid on hepatocytes, C3A human hepatocytes were cultured in medium containing 100 μM palmitic acid (PA).In addition, PA stimulated the static adhesion of U937 monocytes to C3A cells, a phenomenon blocked by inclusion of an anti-TLR-4/MD2 antibody in the culture medium.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA. crive1@lsuhsc.edu

ABSTRACT

Background: Obese patients display an exaggerated morbidity during sepsis. Since consumption of a western-style diet (WD) is a major factor for obesity in the United States, the purpose of the present study was to examine the influence of chronic WD consumption on hepatic inflammation in mice made septic via cecal ligation and puncture (CLP). Feeding mice diets high in fat has been shown to enhance evidence of TLR signaling and this pathway also mediates the hepatic response to invading bacteria. Therefore, we hypothesized that the combined effects of sepsis and feeding WD on TRL-4 signaling would exacerbate hepatic inflammation. Male C57BL/6 mice were fed purified control diet (CD) or WD that was enriched in butter fat (34.4% of calories) for 3 weeks prior to CLP. Intravital microscopy was used to evaluate leukocyte adhesion in the hepatic microcirculation. To demonstrate the direct effect of saturated fatty acid on hepatocytes, C3A human hepatocytes were cultured in medium containing 100 μM palmitic acid (PA). Quantitative real-time PCR was used to assess mRNA expression of tumor necrosis factor-alpha (TNF-α, monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), toll-like receptor-4 (TLR-4) and interleukin-8 (IL-8).

Results: Feeding WD increased firm adhesion of leukocytes in the sinusoids and terminal hepatic venules by 8-fold six hours after CLP; the increase in platelet adhesion was similar to the response observed with leukocytes. Adhesion was accompanied by enhanced expression of TNF-α, MCP-1 and ICAM-1. Messenger RNA expression of TLR-4 was also exacerbated in the WD+CLP group. Exposure of C3A cells to PA up-regulated IL-8 and TLR-4 expression. In addition, PA stimulated the static adhesion of U937 monocytes to C3A cells, a phenomenon blocked by inclusion of an anti-TLR-4/MD2 antibody in the culture medium.

Conclusions: These findings indicate a link between obesity-enhanced susceptibility to sepsis and consumption of a western-style diet.

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Related in: MedlinePlus

The expression of pro-inflammatory markers. Expression of (A) ICAM-1, (B) TNF-α and (C) MCP-1 was assessed using pre-developed assays for real-time PCR according to the manufacturer instructions (Applied Biosystems). Data are presented as mean SEM of at least 5 observations/group. Statistical analysis was performed using two-way ANOVA and Tukey's multiple comparisons test. *p < 0.05 compared to diet-matched sham controls; #p < 0.05 compared to corresponding CD-fed mice exposed to CLP.
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Figure 3: The expression of pro-inflammatory markers. Expression of (A) ICAM-1, (B) TNF-α and (C) MCP-1 was assessed using pre-developed assays for real-time PCR according to the manufacturer instructions (Applied Biosystems). Data are presented as mean SEM of at least 5 observations/group. Statistical analysis was performed using two-way ANOVA and Tukey's multiple comparisons test. *p < 0.05 compared to diet-matched sham controls; #p < 0.05 compared to corresponding CD-fed mice exposed to CLP.

Mentions: To further index the hepatic inflammatory state total RNA was isolated to analyze expression of representative markers. Accordingly, mRNA levels of ICAM-1, TNF-α, and MCP-1 were analyzed using real-time PCR. Expression of TNF-α, and ICAM- 1 was increased by approximately four-fold 6 h after CLP in CD-fed mice (Fig 3A&3B); however, these markers were not elevated by feeding western diet in the absence of CLP. In the WD + CLP group a dramatic augmentation of TNF-α and ICAM-1 expression was observed. Expression of MCP-1 was also increased by approximately 3- and 30-fold in mice fed CD or WD, respectively following CLP. Induction of this chemokine was also enhanced significantly by feeding WD to sham control mice (Figure 3C).


Western diet enhances hepatic inflammation in mice exposed to cecal ligation and puncture.

Rivera CA, Gaskin L, Singer G, Houghton J, Allman M - BMC Physiol. (2010)

The expression of pro-inflammatory markers. Expression of (A) ICAM-1, (B) TNF-α and (C) MCP-1 was assessed using pre-developed assays for real-time PCR according to the manufacturer instructions (Applied Biosystems). Data are presented as mean SEM of at least 5 observations/group. Statistical analysis was performed using two-way ANOVA and Tukey's multiple comparisons test. *p < 0.05 compared to diet-matched sham controls; #p < 0.05 compared to corresponding CD-fed mice exposed to CLP.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2984476&req=5

Figure 3: The expression of pro-inflammatory markers. Expression of (A) ICAM-1, (B) TNF-α and (C) MCP-1 was assessed using pre-developed assays for real-time PCR according to the manufacturer instructions (Applied Biosystems). Data are presented as mean SEM of at least 5 observations/group. Statistical analysis was performed using two-way ANOVA and Tukey's multiple comparisons test. *p < 0.05 compared to diet-matched sham controls; #p < 0.05 compared to corresponding CD-fed mice exposed to CLP.
Mentions: To further index the hepatic inflammatory state total RNA was isolated to analyze expression of representative markers. Accordingly, mRNA levels of ICAM-1, TNF-α, and MCP-1 were analyzed using real-time PCR. Expression of TNF-α, and ICAM- 1 was increased by approximately four-fold 6 h after CLP in CD-fed mice (Fig 3A&3B); however, these markers were not elevated by feeding western diet in the absence of CLP. In the WD + CLP group a dramatic augmentation of TNF-α and ICAM-1 expression was observed. Expression of MCP-1 was also increased by approximately 3- and 30-fold in mice fed CD or WD, respectively following CLP. Induction of this chemokine was also enhanced significantly by feeding WD to sham control mice (Figure 3C).

Bottom Line: Therefore, we hypothesized that the combined effects of sepsis and feeding WD on TRL-4 signaling would exacerbate hepatic inflammation.To demonstrate the direct effect of saturated fatty acid on hepatocytes, C3A human hepatocytes were cultured in medium containing 100 μM palmitic acid (PA).In addition, PA stimulated the static adhesion of U937 monocytes to C3A cells, a phenomenon blocked by inclusion of an anti-TLR-4/MD2 antibody in the culture medium.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA, USA. crive1@lsuhsc.edu

ABSTRACT

Background: Obese patients display an exaggerated morbidity during sepsis. Since consumption of a western-style diet (WD) is a major factor for obesity in the United States, the purpose of the present study was to examine the influence of chronic WD consumption on hepatic inflammation in mice made septic via cecal ligation and puncture (CLP). Feeding mice diets high in fat has been shown to enhance evidence of TLR signaling and this pathway also mediates the hepatic response to invading bacteria. Therefore, we hypothesized that the combined effects of sepsis and feeding WD on TRL-4 signaling would exacerbate hepatic inflammation. Male C57BL/6 mice were fed purified control diet (CD) or WD that was enriched in butter fat (34.4% of calories) for 3 weeks prior to CLP. Intravital microscopy was used to evaluate leukocyte adhesion in the hepatic microcirculation. To demonstrate the direct effect of saturated fatty acid on hepatocytes, C3A human hepatocytes were cultured in medium containing 100 μM palmitic acid (PA). Quantitative real-time PCR was used to assess mRNA expression of tumor necrosis factor-alpha (TNF-α, monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), toll-like receptor-4 (TLR-4) and interleukin-8 (IL-8).

Results: Feeding WD increased firm adhesion of leukocytes in the sinusoids and terminal hepatic venules by 8-fold six hours after CLP; the increase in platelet adhesion was similar to the response observed with leukocytes. Adhesion was accompanied by enhanced expression of TNF-α, MCP-1 and ICAM-1. Messenger RNA expression of TLR-4 was also exacerbated in the WD+CLP group. Exposure of C3A cells to PA up-regulated IL-8 and TLR-4 expression. In addition, PA stimulated the static adhesion of U937 monocytes to C3A cells, a phenomenon blocked by inclusion of an anti-TLR-4/MD2 antibody in the culture medium.

Conclusions: These findings indicate a link between obesity-enhanced susceptibility to sepsis and consumption of a western-style diet.

Show MeSH
Related in: MedlinePlus