Loss of Resistin Improves Glucose Homeostasis in Leptin Deficiency
- Yong Qi12,
- Zhenying Nie12,
- Yun-Sik Lee12,
- Neel S. Singhal12,
- Philipp E. Scherer3,
- Mitchell A. Lazar12 and
- Rexford S. Ahima12
- 1Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
- 2Institute for Diabetes, Obesity and Metabolism, Philadelphia, Pennsylvania
- 3Departments of Cell Biology and Medicine, Albert Einstein College of Medicine, Bronx, New York
- Address correspondence and reprint requests to Rexford S. Ahima, MD, PhD, University of Pennsylvania School of Medicine, Division of Endocrinology, DiabetesMetabolism, 764 Clinical Research Building, 415 Curie Blvd., Philadelphia, PA 19104. E-mail: ahima{at}mail.med.upenn.edu
Abstract
Resistin levels are increased in obesity, and hyperresistinemia impairs glucose homeostasis in rodents. Here, we have determined the role of resistin in ob/ob mice that are obese and insulin resistant because of genetic deficiency of leptin. Loss of resistin increased obesity in ob/ob mice by further lowering the metabolic rate without affecting food intake. Nevertheless, resistin deficiency improved glucose tolerance and insulin sensitivity in these severely obese mice, largely by enhancing insulin-mediated glucose disposal in muscle and adipose tissue. In contrast, in C57BL/6J mice with diet-induced obesity but wild-type leptin alleles, resistin deficiency reduced hepatic glucose production and increased peripheral glucose uptake. Resistin deficiency enhanced Akt phosphorylation in muscle and liver and decreased suppressor of cytokine signaling-3 level in muscle, and these changes were reversed by resistin replacement. Together, these results provide strong support for an important role of resistin in insulin resistance and diabetes associated with genetic or diet-induced obesity.
- ACC, acetyl CoA carboxylase
- AMPK, AMP-activated protein kinase
- BAT, brown adipose tissue
- GIR, glucose infusion rate
- HGP, hepatic glucose production
- pAMPK, phosphorylated AMPK
- pACC, phosphorylated ACC
- PGC-1α, peroxisome proliferator–activated receptor-γ coactivator-1α
- SOCS, suppressor of cytokine signaling
- UCP-1, uncoupling protein-1
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 July 25, 2006.
- Received May 13, 2006.
- DIABETES
