Glucose transporter-2 (GLUT2) promoter mediated transgenic insulin production reduces hyperglycemia in diabetic mice.
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.
Burkhardt
Brant R
BR
Department of Pathology, University of Florida College of Medicine, Gainesville, 32610, USA. burkhardtb@email.chop.edu
Parker
Mathew J
MJ
Zhang
Y Clare
YC
Song
Sihong
S
Wasserfall
Clive H
CH
Atkinson
Mark A
MA
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D000229:Dependovirus / Q000235:genetics; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000628:therapy*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000628:therapy*; D015316:Genetic Therapy; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D051273:Glucose Transporter Type 2 / Q000235:genetics*; D006801:Humans; D007328:Insulin / Q000096:biosynthesis / Q000235:genetics*; D008099:Liver / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D019076:Transgenes
D001786:Blood Glucose; D051273:Glucose Transporter Type 2; D007328:Insulin; D005947:Glucose