Glucose transporter-2 (GLUT2) promoter mediated transgenic insulin production reduces hyperglycemia in diabetic mice

• Published in: FEBS letters 2005-10, Vol.579 (25), p.5759-5764
• Main Authors: Burkhardt, Brant R., Parker, Mathew J., Zhang, Y. Clare, Song, Sihong, Wasserfall, Clive H., Atkinson, Mark A.
• Format: Article
• Language: English
• Subjects: Adeno-associated virus; Animals; Blood Glucose - analysis; Dependovirus - genetics; Diabetes Mellitus, Experimental - complications; Diabetes Mellitus, Experimental - therapy; Diabetes Mellitus, Type 1 - complications; Diabetes Mellitus, Type 1 - therapy; Gene therapy; Genetic Therapy; Glucose - metabolism; Glucose - pharmacology; Glucose Transporter Type 2 - genetics; Glucose transporter-2; Humans; Insulin; Insulin - biosynthesis; Insulin - genetics; Liver; Liver - metabolism; Mice; Promoter Regions, Genetic - drug effects; Promoter Regions, Genetic - genetics; Transgenes; Type 1 diabetes
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2005.09.060

Insulin production afforded by hepatic gene therapy (HGT) retains promise as a potential treatment for type 1 diabetes, but successful approaches have been limited. We employed a novel and previously untested promoter for this purpose, glucose transporter-2 (GLUT2) to drive insulin production via delivery by recombinant adeno-associated virus (rAAV). In vitro, the GLUT2 promoter was capable of robust glucose-responsive expression in transduced HepG2 human hepatoma cells. Therefore, rAAV constructs were designed to express the furin-cleavable human preproinsulin B10 gene, under the control of the murine GLUT2 promoter and packaged for delivery with rAAV expressing the type 5 capsid. Streptozotocin-induced diabetic mice were subjected to hepatic portal vein injection immediately followed by implantation of a sustained-release insulin pellet to allow time for transgenic expression. All mice injected with the rAAV5-GLUT2-fHPIB10 virus remained euglycemic for up to 35 days post-injection, with 50% euglycemic after 77 days post-injection. In contrast, mock-injected mice became hyperglycemic within 15 days post-injection following dissolution of the insulin pellet. Serum levels of both human insulin and C-peptide further confirmed successful transgenic delivery by the rAAV5-GLUT2-fHPIB10 virus. These findings indicate that the GLUT2 promoter may be a potential candidate for regulating transgenic insulin production for hepatic insulin gene therapy in the treatment of type I diabetes.