Mathur N, Andreasen AS, Berg RMG, Pedersen M, Møller K, Pedersen BK and Laye MJ
Aim: Inflammation is thought to play a major role in impaired metabolism. However, the metabolic and inflammatory response of adipose tissue, to a pro-inflammatory stimulus is poorly defined in patients with Type 2 Diabetes Mellitus (T2DM). We therefore aimed to investigate whether adipose tissue in T2DM would display an altered response to E. coli LipoPolySaccharide (LPS).
Materials and methods: Twelve patients with T2DM and 12 control subjects received an intravenous bolus injection of LPS (0.3 ng/kg). Abdominal subcutaneous adipose tissue biopsies, serum and plasma were obtained at 0, 2, 4, 6 and 8 hours after LPS. The gene expression of Tumour Necrosis Factor-α (TNF), InterLeukin-6 (IL-6), lipoprotein lipase (LPL), hormone sensitive lipase (HSL), fatty acid synthase (FASN), adiponectin and peroxisome proliferator-activated recptor γ (PPARγ) was analysed by real time reverse transcription Polymerase Chain Reaction (PCR).
Results: The expression of TNF and IL-6 in adipose tissue increased after LPS administration without any difference between groups (2-way ANOVA, effect of time: p<0.001 and p=0.0001, respectively). In contrast, the expression of LPL, HSL and adiponectin in adipose tissue increased only in control subjects (2-way ANOVA, effect of time X group: p=0.03; p=0.02 and p=0.02, respectively). There was no effect of LPS on FASN or PPARγ in either group.
Conclusion: Patients with T2DM demonstrate a resistance to LPS in terms of inducing important mediators of lipolysis and lipogenesis, although the expression of TNF and IL-6 in adipose tissue increased in both groups. And thus, adipose tissue may contribute to the acute inflammation-related metabolic complications seen in T2DM.