Editors' ChoiceMetabolism

An Insulin Mimic Secreted by Visceral Fat

Science's STKE  25 Jan 2005:
Vol. 2005, Issue 268, pp. tw40
DOI: 10.1126/stke.2682005tw40

Excessive amounts of abdominal visceral fat, sometimes referred to as "bad fat," significantly increase an individual's risk of developing insulin resistance and other metabolic disorders. These adverse health effects may be mediated in part by fat-derived cytokines that circulate in the blood. Fukuhara et al. (see the Perspective by Hug and Lodish) characterized "visfatin," a cytokine that is highly expressed in visceral fat and whose blood levels correlate with obesity. Surprisingly, functional analyses in mice revealed that visfatin has beneficial, insulin-like activity, causing a lowering of blood glucose levels. Even more surprisingly, visfatin was shown to bind to the insulin receptor and activate the insulin signal transduction pathway. While the precise physiological role of visfatin remains to be established, the discovery of this natural insulin mimetic could open exciting new avenues in diabetes research and therapy.

A. Fukuhara, M. Matsuda, M. Nishizawa, K. Segawa, M. Tanaka, K. Kishimoto, Y. Matsuki, M. Murakami, T. Ichisaka, H. Murakami, E. Watanabe, T. Takagi, M. Akiyoshi, T. Ohtsubo, S. Kihara, S. Yamashita, M. Makishima, T. Funahashi, S. Yamanaka, R. Hiramatsu, Y. Matsuzawa, I. Shimomura, Visfatin: A protein secreted by visceral fat that mimics the effects of insulin. Science 307, 426-430 (2005). [Abstract] [Full Text]

C. Hug, H. F. Lodish, Visfatin: A new adipokine. Science 307, 366-367 (2005). [Summary] [Full Text]