Acute-Phase Serum Amyloid A as a Marker of Insulin Resistance in Mice

作者：Scheja Ludger^*; Heese Barbara; Zitzer Heike; Michael Mervyn D; Siesky Angela M; Pospisil Heike; Beisiegel Ulrike; Seedorf Klaus

来源：Experimental Diabetes Research, 2008, 230837.

DOI：10.1155/2008/230837

Acute-phase serum amyloid A (A-SAA) was shown recently to correlate with obesity and insulin resistance in humans. However, the mechanisms linking obesity-associated inflammation and elevated plasma A-SAA to insulin resistance are poorly understood. Using high-fat diet-(HFD-) fed mice, we found that plasma A-SAA was increased early upon HFD feeding and was tightly associated with systemic insulin resistance. Plasma A-SAA elevation was due to induction of Saa1 and Saa2 expression in liver but not in adipose tissue. In adipose tissue Saa3 was the predominant isoform and the earliest inflammatory marker induced, suggesting it is important for initiation of adipose tissue inflammation. To assess the potential impact of A-SAA on adipose tissue insulin resistance, we treated 3T3-L1 adipocytes with recombinant A-SAA. Intriguingly, physiological levels of A-SAA caused alterations in gene expression closely resembling those observed in HFD- fed mice. Proinflammatory genes (Ccl2, Saa3) were induced while genes critical for insulin sensitivity (Irs1, Adipoq, Glut4) were down-regulated. Our data identify HFD- fed mice as a suitable model to study A-SAA as a biomarker and a novel possible mediator of insulin resistance.

• 出版日期2008
• 单位上海生物信息技术研究中心