Impaired adipogenesis in insulin-like growth factor binding protein-1 transgenic mice

• Published in: Journal of endocrinology Vol. 162; no. 3; pp. 457 - 465
• Main Authors: Rajkumar, K, Modric, T, Murphy, LJ
• Format: Journal Article
• Language: English
• Published: Colchester BioScientifica 01.09.1999; Portland Press
• Subjects: Adipocytes - drug effects; Adipocytes - pathology; Adipose Tissue - drug effects; Adipose Tissue - metabolism; Adipose Tissue - pathology; Animals; Biological and medical sciences; Body Weight; Cell Differentiation; Cell Division; Cells, Cultured; Colony-Forming Units Assay; Fundamental and applied biological sciences. Psychology; Glucose - administration & dosage; Insulin - pharmacology; Insulin-Like Growth Factor Binding Protein 1 - genetics; Insulin-Like Growth Factor Binding Protein 1 - metabolism; Insulin-Like Growth Factor I - pharmacology; Insulin-Like Growth Factor I - physiology; Male; Mice; Mice, Transgenic; Obesity - metabolism; Obesity - pathology; Protein Binding; Vertebrates: skin, associated glands, phaneres, light organs, various exocrine glands (salt gland, uropygial gland...), adipose tissue, connective tissue; Cell proliferation; Adipocyte; Obesity; Adipose tissue; Rodentia; Transgenic animal; Gene overexpression; Insulin like growth factor 1; Insulin like growth factor binding protein; Metabolic disorder; Vertebrata; Mammalia; Mouse; Differentiation
• ISSN: 0022-0795; 1479-6805
• DOI: 10.1677/joe.0.1620457

Differentiation of precursor cells into mature fat cells is accompanied by enhanced expression of insulin-like growth factor (IGF)-I and is stimulated by multiple hormones including growth hormone, glucocorticoids, IGF-I and insulin. We used transgenic mice that overexpress insulin-like growth factor binding protein-1 to investigate the role of IGF-I in the accumulation of fat tissue. In response to a sucrose-enriched diet, transgenic mice gained significantly less body weight and the epididymal fat mass was significantly reduced compared with wild-type mice. The increase in adipocyte size was also significantly reduced in transgenic mice compared with wild-type mice. Fewer colonies were generated from adipose tissue from transgenic mice and the mitogenic response of these cells to IGF-I was significantly reduced compared with those from wild-type mice. Induction of glycerol-3-phosphate dehydrogenase, a measure of adipocyte differentiation, by IGF-I but not insulin, was reduced in preadipocytes from transgenic mice. These data indicate that IGF-I has a critical role in the proliferation of adipocyte precursors, the differentiation of preadipocytes and the development of obesity in response to calorie excess.