A Human-Specific Role of Cell Death-Inducing DFFA (DNA Fragmentation Factor-α)-Like Effector A (CIDEA) in Adipocyte Lipolysis and Obesity
- Elisabet Arvidsson Nordström1,
- Mikael Rydén1,
- Emma C. Backlund2,
- Ingrid Dahlman1,
- Maria Kaaman1,
- Lennart Blomqvist3,
- Barbara Cannon2,
- Jan Nedergaard2 and
- Peter Arner1
- 1Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- 2Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- 3Department of Surgery, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Address correspondence and reprint requests to Peter Arner, Professor, MD, PhD, Karolinska Institutet, Karolinska University Hospital Huddinge, M63 SE-141 86 Stockholm, Sweden. E-mail: peter.arner{at}medhs.ki.se
Abstract
Elevated circulating fatty acid concentration is a hallmark of insulin resistance and is at least in part attributed to the action of adipose tissue-derived tumor necrosis factor-α (TNF-α) on lipolysis. Cell death-inducing DFFA (DNA fragmentation factor-α)-like effector A (CIDEA) belongs to a family of proapoptotic proteins that has five known members in humans and mice. The action of CIDEA is unknown, but CIDEA-null mice are resistant to obesity and diabetes. We investigated CIDEA in adipose tissue of obese and lean humans and mice. The mRNA was expressed in white human fat cells and in brown mouse adipocytes. The adipose mRNA expression of CIDEA in mice was not influenced by obesity. However, CIDEA expression was decreased twofold in obese humans and normalized after weight reduction. Low adipose CIDEA expression was associated with several features of the metabolic syndrome. Human adipocyte depletion of CIDEA by RNA interference stimulated lipolysis and increased TNF-α secretion by a posttranscriptional effect. Conversely, TNF-α treatment decreased adipocyte CIDEA expression via the mitogen-activated protein kinase c-Jun NH2-terminal kinase. We propose an important and human-specific role for CIDEA in lipolysis regulation and metabolic complications of obesity, which is at least in part mediated by cross-talk between CIDEA and TNF-α.
- BAT, brown adipose tissue
- CIDEA, cell death-inducing DFFA (DNA fragmentation factor-α)-like effector A
- HOMA, homeostasis model assessment
- JNK, c-Jun NH2-terminal kinase
- MAPK, mitogen-activated protein kinase
- MCP-1, monocyte chemoattractant protein-1
- siRNA, short interfering RNA
- TNF-α, tumor necrosis factor-α
- WAT, white adipose tissue
Footnotes
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Accepted March 14, 2005.
- Received December 10, 2004.
- DIABETES
