Short-term high-fat overfeeding does not induce NF-κB inflammatory signaling in subcutaneous white adipose tissue

It is unclear how white adipose tissue (WAT) inflammatory signaling proteins respond during the early stages of overnutrition.

Objective

To investigate the effect of short-term, high-fat overfeeding on fasting abdominal subcutaneous WAT total content and phosphorylation of proteins involved in nuclear factor-κB (NF-κB) inflammatory signaling, systemic metabolic measures and inflammatory biomarkers.

Design

Individuals consumed a high-fat (65% total energy total fat), high-energy (50% above estimated energy requirements) diet for 7 days.

Results Fifteen participants (age 27 ± 1 y; BMI 24.4 ± 0.6 kg/m2) completed the study. Body mass increased following high-fat overfeeding (+1.2 ± 0.2 kg; P < 0.0001). However, total content and phosphorylation of proteins involved in NF-κB inflammatory signaling were unchanged following the intervention. Fasting serum glucose (+0.2 ± 0.0 mmol/L), total cholesterol (+0.4 ± 0.1 mmol/L), low-density lipoprotein cholesterol (+0.3 ± 0.1 mmol/L), high-density lipoprotein cholesterol (+0.2 ± 0.0 mmol/L), and lipopolysaccharide-binding protein (LBP; +4.7 ± 2.1 µg/mL) increased, whereas triacylglycerol concentrations (-0.2 ± 0.1 mmol/L) decreased following overfeeding (all P < 0.05). Systemic biomarkers (insulin, soluble cluster of differentiation 14 (CD14), C-reactive protein, IL-6, TNF-α and monocyte chemoattractant protein-1) and the proportion and concentration of circulating CD14+ monocytes were unaffected by overfeeding.

Conclusion

Acute lipid oversupply did not impact on total content or phosphorylation of proteins involved in WAT NF-κB inflammatory signaling, despite modest weight gain and metabolic alterations. Systemic LBP, which is implicated in the progression of low-grade inflammation during the development of obesity, increased in response to a 7-day high-fat overfeeding period.