Obesity-associated improvements in metabolic profile through expansion of adipose tissue
Ja-Young Kim, … , Gary J. Schwartz, Philipp E. Scherer
Ja-Young Kim, … , Gary J. Schwartz, Philipp E. Scherer
Published September 4, 2007
Citation Information: J Clin Invest. 2007;117(9):2621-2637. https://doi.org/10.1172/JCI31021.
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Research Article Metabolism

Obesity-associated improvements in metabolic profile through expansion of adipose tissue

Abstract

Excess caloric intake can lead to insulin resistance. The underlying reasons are complex but likely related to ectopic lipid deposition in nonadipose tissue. We hypothesized that the inability to appropriately expand subcutaneous adipose tissue may be an underlying reason for insulin resistance and β cell failure. Mice lacking leptin while overexpressing adiponectin showed normalized glucose and insulin levels and dramatically improved glucose as well as positively affected serum triglyceride levels. Therefore, modestly increasing the levels of circulating full-length adiponectin completely rescued the diabetic phenotype in ob/ob mice. They displayed increased expression of PPARγ target genes and a reduction in macrophage infiltration in adipose tissue and systemic inflammation. As a result, the transgenic mice were morbidly obese, with significantly higher levels of adipose tissue than their ob/ob littermates, leading to an interesting dichotomy of increased fat mass associated with improvement in insulin sensitivity. Based on these data, we propose that adiponectin acts as a peripheral “starvation” signal promoting the storage of triglycerides preferentially in adipose tissue. As a consequence, reduced triglyceride levels in the liver and muscle convey improved systemic insulin sensitivity. These mice therefore represent what we believe is a novel model of morbid obesity associated with an improved metabolic profile.

Authors

Ja-Young Kim, Esther van de Wall, Mathieu Laplante, Anthony Azzara, Maria E. Trujillo, Susanna M. Hofmann, Todd Schraw, Jorge L. Durand, Hua Li, Guangyu Li, Linda A. Jelicks, Mark F. Mehler, David Y. Hui, Yves Deshaies, Gerald I. Shulman, Gary J. Schwartz, Philipp E. Scherer

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Figure 4

Excess adiponectin normalizes pancreatic islet histology and improves both local and systemic inflammation.

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Excess adiponectin normalizes pancreatic islet histology and improves ...
(A) Immunofluorescence staining for insulin (green) and glucagon (red) was performed in pancreatic sections from 10-week-old male WT mice (top), ob/ob littermates (middle), and adiponectin transgenic ob/ob mice. (B) Immunohistochemical staining of gonadal adipose tissue with anti-F4/80 antibodies suggests reduced infiltration of macrophages. Note that the difference in average adipocyte size between the 2 genotypes is apparent but less pronounced at this younger age. (C) FACS analysis of the stromal vascular fraction using F4/80 antibodies (left) and qRT-PCR for F4/80 (right) (n = 10 mice/group) were performed in gonadal WAT of adiponectin transgenic ob/ob mice and ob/ob littermates. Black curve shows control IgG staining; red curve shows anti-F4/80 staining. (D) mRNA levels of vWF and VCAM-1 from WAT were measured by qRT-PCR. A ratio of VCAM-1/vWF is provided as an indicator of local inflammation in the vascular endothelium. (E) Circulating IL-6 was measured in adiponectin transgenic ob/ob mice and ob/ob littermates (top); adipose tissue TNF-α message levels (bottom). (C–E) For these studies, 14-week-old male mice were used (n = 10 mice/group). *P < 0.05. Panels C–E were analyzed by Student’s t test.