Cideb Regulates Diet-Induced Obesity, Liver Steatosis, and Insulin Sensitivity by Controlling Lipogenesis and Fatty Acid Oxidation

  1. John Zhong Li1,
  2. Jing Ye23,
  3. Bofu Xue1,
  4. Jingzhong Qi2,
  5. Jing Zhang3,
  6. Zhihong Zhou4,
  7. Qing Li3,
  8. Zilong Wen4 and
  9. Peng Li12
  1. 1Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
  2. 2Protein Science Laboratory of Ministry of Education, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China
  3. 3Department of Pathology, Fourth Military Medical University, Xi'an, China
  4. 4Institute of Molecular and Cell Biology, Singapore
  1. Address correspondence and reprint requests to Dr. Peng Li, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China. E-mail: li-peng{at}mail.tsinghua.edu.cn

Abstract

OBJECTIVE—Our previous study suggests that Cidea, a member of Cide family proteins that share sequence homology with the DNA fragmentation factor and are expressed at high levels in brown adipose tissue, plays an important role in the development of obesity. Cideb, another member of Cide family protein, is highly expressed in the liver. We would like to understand the physiological role of Cideb in the regulation of energy expenditure and lipid metabolism.

RESEARCH DESIGN AND METHODS—We generated Cideb-null mice by homolog recombination and then fed both wild-type and Cideb-null mice with high-fat diet (58% fat). We then characterized the animals’ adiposity index, food intake, whole-body metabolic rate, liver morphology, rate of fatty acid synthesis and oxidation, insulin sensitivity, and gene expression profile.

RESULTS—Cideb-null mice had lower levels of plasma triglycerides and free fatty acids and were resistant to high-fat diet–induced obesity and live steatosis. In addition, Cideb mutant mice displayed significantly increased insulin sensitivity and enhanced rate of whole-body metabolism and hepatic fatty acid oxidation. More importantly, Cideb-null mice showed decreased lipogenesis and reduced expression levels of acetyl-CoA carboxylase, fatty acid synthase, and stearol-CoA desaturase. We further demonstrated that expression levels of sterol response element binding protein 1c was significantly decreased in Cideb-deficient mice.

CONCLUSIONS—Our data demonstrate that Cideb is a novel important regulator in lipid metabolism in the liver. Cideb may represent a new therapeutic target for the treatment of obesity, diabetes, and liver steatosis.

Footnotes

  • Published ahead of print at http://diabetes.diabetesjournals.org on 7 August 2007. DOI: 10.2337/db07-0040.

  • Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/db07-0040.

  • J.Z.L. and J.Y. contributed equally to this work.

  • 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.

    • Accepted June 29, 2007.
    • Received January 11, 2007.
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  1. Diabetes vol. 56 no. 10 2523-2532
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