Effects of IGFBP-2 overexpression in vitro and in vivo.
Insulin-like growth factor-binding proteins (IGFBPs) are important modulators of IGF actions and may have both stimulatory and inhibitory effects. Expression of IGFBP-2 is increased after fasting and in a variety of pathological conditions. However, the specific role of IGFBP-2 in growth physiology remains to be determined. In this review, we summarize data from in vitro and in vivo models suggesting that IGFBP-2 has mainly inhibitory effects on IGF actions. Since the growth hormone (GH)/IGF system is involved in a number of pathological alterations of the kidney and these changes may--at least in part--be due to increased IGF-I, local overexpression of inhibitory IGFBP-2 in the kidney might prevent IGF-I-induced lesions. This hypothesis will be tested by crossing GH transgenic mice, a common model of glomerulosclerosis, with transgenic mice characterized by systemic and renal overexpression of IGFBP-2.
Institute of Molecular Animal Breeding and Genetics, Ludwig-Maximilian University, Munich, Germany. ewolf@lmb.uni-muenchen.de
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Wolf
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Lahm
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Wu
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Wanke
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Hoeflich
D000818:Animals; D002478:Cells, Cultured / Q000378:metabolism; D013006:Growth Hormone / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007674:Kidney Diseases / Q000503:physiopathology*; D008107:Liver Diseases / Q000378:metabolism; D008171:Lung Diseases / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism; D013002:Somatomedins / Q000502:physiology
D018971:Insulin-Like Growth Factor Binding Protein 2; D013002:Somatomedins; D013006:Growth Hormone