Fibroblast growth factor 1 (FGF1) is an autocrine/paracrine regulator whose binding to heparan sulphate proteoglycans effectively precludes its circulation1,2. Although FGF1 is known as a mitogenic factor, FGF1 knockout mice develop insulin resistance when stressed by a high-fat diet, suggesting a potential role in nutrient homeostasis3,4. Here we show that parenteral delivery of a single dose of recombinant FGF1 (rFGF1) results in potent, insulin-dependent lowering of glucose levels in diabetic mice that is dose-dependent but does not lead to hypoglycaemia. Chronic pharmacological treatment with rFGF1 increases insulin-dependent glucose uptake in skeletal muscle and suppresses the hepatic production of glucose to achieve whole-body insulin sensitization. The sustained glucose lowering and insulin sensitization attributed to rFGF1 are not accompanied by the side effects of weight gain, liver steatosis and bone loss associated with current insulin-sensitizing therapies. We also show that the glucose-lowering activity of FGF1 can be dissociated from its mitogenic activity and is mediated predominantly via FGF receptor 1 signalling. Thus we have uncovered an unexpected, neomorphic insulin-sensitizing action for exogenous non-mitogenic human FGF1 with therapeutic potential for the treatment of insulin resistance and type 2 diabetes.
We thank L. Chong, J. Alvarez, S. Kaufman, B. Collins, X. Zhao, S. Liu, A. Jurdzinski, A. Bleeker, K. Bijsterveld, D. Oh and G. Bandyopadhyay for technical assistance, and L. Ong and C. Brondos for administrative assistance. Computed tomography was performed at the Veterans Medical Research Foundation. R.M.E. is a Howard Hughes Medical Institute Investigator at the Salk Institute and March of Dimes Chair, and is supported by National Institutes of Health (NIH) grants (DK057978, DK090962, HL088093, HL105278 and ES010337), the Glenn Foundation for Medical Research, the Leona M. and Harry B. Helmsley Charitable Trust, Ipsen/Biomeasure, the California Institute for Regenerative Medicine and The Ellison Medical Foundation. C.L. and M.D. are funded by the National Health and Medical Research Council (grants 512354, 632886 and 1043199); J.W.J. by the European Research Council (grant IRG-277169), the Human Frontier Science Program (CDA00013/2011-C), the Netherlands Organisation for Scientific Research (VIDI grant 016.126.338), the Dutch Digestive Foundation (grant WO 11-67) and the Dutch Diabetes Foundation (grant 2012.00.1537); J.M.O. by NIH grants (DK-033651, DK-074868, T32-DK-007494, DK-063491 and P01-DK054441-14A1) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development/NIH through cooperative agreement of U54-HD-012303-25 as part of the specialized Cooperative Centers Program in Reproduction and Infertility Research; M.M. by the National Institute of Dental and Craniofacial Research grant (DE13686); and M.A. by an F32 Ruth L. Kirschstein National Research Service Award (National Institute of Diabetes and Digestive and Kidney Diseases).