title: An efficient GLP-1 expression system using two-step transcription amplification.
abstract: Glucagon-like peptide 1 (GLP-1) is an insulinotropic protein. It was reported that the continuous infusion of GLP-1 normalized the blood glucose level in type 2 diabetes animal model. However, the short half-life of GLP-1 has limited its application in clinical settings and prompted us to develop a GLP-1 gene therapy system. Our previous results showed that the delivery of pbeta-GLP-1 using polyethylenimine (PEI) reduced the blood glucose level effectively. However, the glucose level was not completely normalized. In the present study, the more efficient GLP-1 expression system was developed using two-step transcription amplification (TSTA). To evaluate the TSTA system, pbeta-Gal4-p65 and pUAS-Luc were constructed. The pUAS-Luc/pbeta-Gal4-p65 system showed the highest transfection efficiency at a 2:1 pUAS-Luc/pbeta-Gal4-p65 weight ratio. In addition, the transgene expression by the TSTA system was at least 4 times higher than pbeta-Luc. To apply the TSTA system to the GLP-1 expression plasmid, pUAS-GLP-1 was constructed. The pUAS-GLP-1/pbeta-Gal4-p65 system showed higher mRNA level than pbeta-GLP-1. In addition, the level of GLP-1 by the pUAS-GLP-1/pbeta-Gal4-p65 system was more than 4 times higher than pbeta-GLP-1. Therefore, the TSTA GLP-1 expression system may be useful to develop gene therapy system for type 2 diabetes.
authors.affiliation: Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Minhyung
authors.initials: M
authors.lastname: Lee
authors.forename: Seungjoon
authors.initials: S
authors.lastname: Oh
authors.forename: Cheol-Hee
authors.initials: CH
authors.lastname: Ahn
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Kim
authors.forename: Byoung Doo
authors.initials: BD
authors.lastname: Rhee
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Ko
mesh_terms: D002460:Cell Line; D003920:Diabetes Mellitus / Q000235:genetics / Q000378:metabolism / Q000628:therapy; D004797:Enzyme-Linked Immunosorbent Assay; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D052216:Glucagon-Like Peptide 1 / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D007097:Imines / Q000737:chemistry; D008156:Luciferases; D049408:Luminescent Agents; D010957:Plasmids; D011095:Polyethylenes / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D007097:Imines; D049408:Luminescent Agents; D011095:Polyethylenes; C505405:poly(ethylene imine); D052216:Glucagon-Like Peptide 1; D008156:Luciferases