Aktuelle Ernährungsmedizin 2009; 34 - P6
DOI: 10.1055/s-0029-1223906

The adipokine amyloid precursor protein is induced by tumor necrosis factor α in 3T3-L1 adipocytes

G Sommer 1, S Kralisch 1, U Lossner 1, M Bluher 1, M Stumvoll 1, M Fasshauer 1
  • 1University of Leipzig, Department of Internal Medicine III, 04103 Leipzig, Germany

Introduction:

Chronic overnutrition is strongly linked to subclinical inflammation and the development of metabolic disease. In the current study, the regulation of the novel adipokine amyloid precursor protein (APP) by the proinflammatory and insulin resistance-inducing cytokine tumor necrosis factor (TNF) α was determined in 3T3-L1 adipocytes.

Methods:

Differentiated 3T3-L1 Adipocytes were stimulated with recombinant TNFα. Total RNA was isolated and APP mRNA expression was analyzed by quantitative real-time RT-PCR. In addition, Western Blotting analysis was performed to determine APP protein synthesis.

Results:

APP protein synthesis and mRNA expression were significantly increased by TNFα with maximal induction observed after 24h. Furthermore, TNFα significantly induced APP mRNA expression dose-dependently with maximal 6.4-fold upregulation seen at 100ng/ml effector. Moreover, inhibitor experiments suggested that TNFα-induced APP expression was mediated by nuclear factor κ B.

Conclusion:

We show for the first time a potent upregulation of APP by TNFα suggesting a potential role of this adipokine in the development of overnutrition-associated insulin resistance and inflammation.