Remission of Diabetes by Insulin Gene Therapy Using a Hepatocyte-specific and Glucose-responsive Synthetic Promoter

• Published in: Molecular therapy Vol. 19; no. 3; pp. 470 - 478
• Main Authors: Han, Jaeseok, McLane, Brienne, Kim, Eung-Hwi, Yoon, Ji-Won, Jun, Hee-Sook
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-03-2011; Elsevier Limited; Nature Publishing Group
• Subjects: Adenoviridae - genetics; Adenoviridae - metabolism; Adenovirus; Animals; Cell Line; Cloning; Cytomegalovirus; Diabetes; Diabetes Mellitus, Type 1 - therapy; Disease Models, Animal; Gene expression; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Gene Library; Gene Order; Gene therapy; Genes, Synthetic; Genetic Therapy; Genetic Vectors - administration & dosage; Genetic Vectors - genetics; Genetic Vectors - metabolism; Glucose; Glucose - metabolism; Glucose - pharmacology; HeLa Cells; Humans; Hyperglycemia - therapy; Insulin; Insulin - genetics; Insulin - metabolism; Kinases; Liver; Liver - metabolism; Male; Metabolism; Mice; Mice, SCID; Organ Specificity - genetics; Original; Plasmids; Promoter Regions, Genetic - genetics; Proteins; Rats; Rats, Sprague-Dawley; Remission (Medicine); Survival Analysis
• ISSN: 1525-0016; 1525-0024
• DOI: 10.1038/mt.2010.255

Efficient production of insulin in response to changes in glucose levels has been a major issue for insulin gene therapy to treat diabetes. To express target genes in response to glucose specifically in hepatocytes, we generated a synthetic promoter library containing hepatocyte nuclear factor-1, CAAT/enhancer-binding protein (C/EBP) response element, and glucose-response element. Combinations of these three cis-elements in 3-, 6-, or 9-element configurations were screened for transcriptional activity and then glucose responsiveness in vitro. The most effective promoter (SP23137) was selected for further study. Intravenous administration of a recombinant adenovirus expressing furin-cleavable rat insulin under control of the SP23137 promoter into streptozotocin (STZ)-induced diabetic mice resulted in normoglycemia, which was maintained for >30 days. Glucose tolerance tests showed that treated mice produced insulin in response to glucose and cleared exogenous glucose from the blood in a manner similar to nondiabetic control mice, although the clearance was somewhat delayed. Insulin expression was seen specifically in the liver and not in other organs. These observations indicate the potential of this synthetic, artificial promoter to regulate glucose-responsive insulin production and remit hyperglycemia, thus providing a new method of liver-directed insulin gene therapy for type 1 diabetes.