Adipose Fatty Acid Binding Protein Promotes Saturated Fatty Acid-Induced Macrophage Cell Death through Enhancing Ceramide Production.

Abstract

Macrophages play a critical role in obesity-associated chronic inflammation and disorders. However, the molecular mechanisms underlying the response of macrophages to elevated fatty acids (FAs) and their contribution to metabolic inflammation in obesity remain to be fully elucidated. In this article, we report a new mechanism by which dietary FAs, in particular, saturated FAs (sFAs), are able to directly trigger macrophage cell death. We demonstrated that excess sFAs, but not unsaturated FAs, induced the production of cytotoxic ceramides (Cers) in macrophage cell lines. Most importantly, expression of adipose FA binding protein (A-FABP) in macrophages facilitated metabolism of excess sFAs for Cer synthesis. Inhibition or deficiency of A-FABP in macrophage cell lines decreased sFA-induced Cer production, thereby resulting in reduced cell death. Furthermore, we validated the role of A-FABP in promoting sFA-induced macrophage cell death with primary bone marrow-derived macrophages and high-fat diet-induced obese mice. Altogether, our data reveal that excess dietary sFAs may serve as direct triggers in induction of Cer production and macrophage cell death through elevated expression of A-FABP, thus establishing A-FABP as a new molecular sensor in triggering macrophage-associated sterile inflammation in obesity.

• Authors: Yuwen Zhang, Enyu Rao, Jun Zeng, Jiaqing Hao, Yanwen Sun, Shujun Liu, Edward R Sauter, David A Bernlohr, Margot P Cleary, Jill Suttles, Bing Li
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 198 Issue 2 Pg. 798-807 (01 15 2017) ISSN: 1550-6606 [Electronic] United States
• PMID: 27920274 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2017 by The American Association of Immunologists, Inc.

Chemical References

• Ceramides
• Fabp4 protein, mouse
• Fatty Acid-Binding Proteins
• Fatty Acids

Topics

• Animals
• Blotting, Western
• Cell Death
• Ceramides (biosynthesis)
• Diet, High-Fat
• Fatty Acid-Binding Proteins (metabolism)
• Fatty Acids (adverse effects)
• Flow Cytometry
• Gene Knockdown Techniques
• Macrophages (metabolism, pathology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Microscopy, Confocal
• Microscopy, Electron, Transmission
• Obesity (metabolism)
• Real-Time Polymerase Chain Reaction