title: Efficient GLP-1 gene delivery using two-step transcription amplification plasmid system with a secretion signal peptide and arginine-grafted bioreducible polymer.
abstract: Glucagon-like peptide (GLP-1) encoding dual plasmid (pDNA) system (TSTA (SP-GLP-1)) which is composed of pβ-Gal4-p65 and pUAS-SP-GLP-1 was constructed to improve the production and secretion of expressed GLP-1 by combining the advantages of signal peptide (SP) and two-step transcription amplification (TSTA) system. Its potential for GLP-1 gene delivery system was investigated with employment of arginine-grafted bioreducible polymer (ABP) as a gene carrier. Their polyplexes have about 140nm-sizes and 20mV Zeta-potential values. ABP showed no cytotoxicity contrary to PEI25k. It was found in RT-PCR experiments that TSTA-SP pDNA systems showed increased GLP-1 gene transcription level in comparison with mono pDNA system (pβ-GLP-1). It was also observed in GLP-1 ELISA that GLP-1 secretion level of TSTA (SP-GLP-1) pDNA system was 2.7-3.4 times higher than those of pβ-GLP-1 and 1.5-1.7 times than TSTA (GLP-1). Additionally, 2.5-3.5 folds increased level of GLP-1 secretion was found in ABP gene carrier system in comparison with PEI25k. When transfection medium containing secreted GLP-1 was transferred to NIT-1 insulinoma cells, the highest secretion level of insulin was induced in ABP/TSTA (SP-GLP-1) polyplex medium-treated cells. Therefore, this novel system could be utilized as a safe and efficient GLP-1 gene delivery system for type 2 diabetes therapy.
authors.affiliation: Department of Biosystems and Biomaterials Science and Engineering, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Tae-Il
authors.initials: TI
authors.lastname: Kim
authors.forename: Minhyung
authors.initials: M
authors.lastname: Lee
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Kim
mesh_terms: D000818:Animals; D001120:Arginine / Q000737:chemistry; D045744:Cell Line, Tumor; D015316:Genetic Therapy / Q000379:methods*; D052216:Glucagon-Like Peptide 1 / Q000235:genetics* / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D051379:Mice; D041681:NIH 3T3 Cells; D010957:Plasmids / Q000235:genetics; D011073:Polyamines / Q000737:chemistry; D021382:Protein Sorting Signals; D014158:Transcription, Genetic; D014162:Transfection / Q000379:methods
chemical_list: D007328:Insulin; D011073:Polyamines; D021382:Protein Sorting Signals; C534803:arginine-grafted bioreducible poly(disulfide amine)polymer; D052216:Glucagon-Like Peptide 1; D001120:Arginine