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. 2010 Jul 15;3(3):134-142.
doi: 10.70252/OVIU5838. eCollection 2010.

Longitudinal, Diet-induced Weight Gain is Associated with Increased Blood Monocytes and Reduced TLR4 Expression

Kelley Strohacker  1 , Richard J Simpson  1 , Katie C Carpenter  1 , Whitney L Breslin  1 , Brian K McFarlin  1
Affiliations

Longitudinal, Diet-induced Weight Gain is Associated with Increased Blood Monocytes and Reduced TLR4 Expression

Kelley Strohacker et al. Int J Exerc Sci. .

Abstract

Excessive weight gain increases systemic inflammation resulting in increased disease risk. Toll-like receptor 4 (TLR4) reportedly mediates increases in inflammation; however, its role in obesity-induced inflammation has not been fully evaluated. The purpose of this study was to determine the longitudinal effect of diet-induced weight gain on blood monocyte concentration and cell-surface TLR4 expression. Male CD-1 mice were randomly assigned to high-fat (HF, n = 12) or low-fat (LF, n = 13) groups. Non-lethal, saphenous vein blood samples were collected at 0, 4, 8 and 12 weeks of treatment. Three-color flow cytometry was used to measure monocyte (CD11b+/CD14+) concentration and TLR4 cell-surface expression. Data were analyzed with a repeated measures ANOVA; significance was set at P<0.05. Body weight at week 12 was 21% greater in HF than LF (P<0.05). At week 12 HF had 155% more monocytes (P<0.05) with 24% less TLR4 than LF; Monocyte concentration and body weight at week 12 was negatively correlated with TLR4 gMFI (P<0.05). The observed effects of high-fat feeding on blood monocytes are consistent with a phenotype, which may be associated with premature morbidity. The observed monocyte responses may be associated with immune dysfunction and diminished response to infection.

Keywords: 60% fat diet; CD-1 mice; flow cytometry; non-lethal; obesity.

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Figures

Figure 1
Figure 1. Body Weight
The present study examined peripheral blood monocyte TLR4 expression in male CD-1 mice gaining weight by consuming either a high-fat (HF, 60% kcal) or a low-fat (LF, 10% kcal) diet for 12 weeks. The results presented are for body weight in grams. Values are expressed as mean ± SE. ■ indicates a significant difference between HF and LF (P<0.05). ▼ indicates a significant change from baseline in the same group (P< 0.05).
Figure 2
Figure 2. Food Intake
The present study examined peripheral blood monocyte TLR4 expression in male CD-1 mice gaining weight by consuming either a high-fat (HF, 60% kcal) or a low-fat (LF, 10% kcal) diet for 12 weeks. The results presented are for food intake per mouse in kilocalories. Values are expressed as mean ± SE. ■ indicates a significant difference between HF and LF (P<0.05). ▼ indicates a significant change from baseline in the same group (P < 0.05).
Figure 3
Figure 3. Monocyte Concentration
The present study examined peripheral blood monocyte TLR4 expression in male CD-1 mice gaining weight by consuming either a high-fat (HF, 60% kcal) or a low-fat (LF, 10% kcal) diet for 12 weeks. The results presented are for the concentration of CD11b+/CD14+ monocytes (x104 cells/mL). Values are expressed as mean ± SE. ■ indicates a significant difference between HF and LF (P<0.05). ▼ indicates a significant change from baseline in the same group (P < 0.05).
Figure 4
Figure 4. Monocyte Cell-Surface TLR4 Expression
The present study examined peripheral blood monocyte TLR4 expression in male CD-1 mice gaining weight by consuming either a high-fat (HF, 60% kcal) or a low-fat (LF, 10% kcal) diet for 12 weeks. The results presented are for cell-surface TLR4 gMFI on CD11b+/CD14+ monocytes in panel B. Values are expressed as mean ± SE. ■ indicates a significant difference between HF and LF (P<0.05). ▼ indicates a significant change from baseline in the same
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References

    1. Afiune Neto A, Mansur Ade P, Avakian SD, Gomes EP, Ramires JA. [Monocytosis is an independent risk marker for coronary artery disease]. Arq Bras Cardiol. 2006;86(3):240–4. - PubMed
    1. Beutler B. Tlr4: central component of the sole mammalian LPS sensor. Curr Opin Immunol. 2000;12(1):20–6. - PubMed
    1. Boehmer ED, Goral J, Faunce DE, Kovacs EJ. Age-dependent decrease in Toll-like receptor 4-mediated proinflammatory cytokine production and mitogen-activated protein kinase expression. J Leukoc Biol. 2004;75(2):342–9. - PubMed
    1. Branger J, Knapp S, Weijer S, Leemans JC, Pater JM, Speelman P, Florquin S, van der Poll T. Role of Toll-like receptor 4 in gram-positive and gram-negative pneumonia in mice. Infect Immun. 2004;72(2):788–94. - PMC - PubMed
    1. Cani PD, Amar J, Iglesias MA, Poggi M, Knauf C, Bastelica D, Neyrinck AM, Fava F, Tuohy KM, Chabo C, Waget A, Delmee E, Cousin B, Sulpice T, Chamontin B, Ferrieres J, Tanti JF, Gibson GR, Casteilla L, Delzenne NM, Alessi MC, Burcelin R. Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes. 2007;56(7):1761–72. - PubMed

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