Glucose-dependent Insulin Secretion from Genetically Engineered K-cells Using EBV-based Episomal Vector

Autor: Bong Yun Cha, Ki Ho Song, Sook Kyung Lee, Kun Ho Yoon, Soon Jip Yoo, Hyang Sook Lim, Yu Bai Ahn, Hyun Shik Son, Je Ho Han, Seung Hyun Ko, Sung Dae Moon, Ju Hee Kim, Ho Young Son, Sung Joo Kim
Rok vydání: 2007
Předmět:
Zdroj: The Journal of Korean Diabetes Association. 31:9
ISSN: 1015-6461
Popis: Abstract - - Abstract - - Abstract - - Abstract - Background: Type 1 diabetes mellitus is an autoimmune disease resulting in destruction of the pancreatic beta cells. Insulin gene therapy for these patients has been vigorously researched. The strategy for achieving glucose-dependent insulin secretion in gene therapy relies on glucose-responsive transcription of insulin mRNA and the constitutive secretory pathway of target non-beta cells. We observed that genetically engineered K-cells using Epstein-Barr virus (EBV)-based episomal vector can produce glucose-regulated insulin production. Methods: Green fluorescent protein (GFP) or rat-preproinsulin (PPI) expression cassette transcriptionally controlled by the promoter of glucose dependent insulinotropic peptide (GIPP) is fused to pCEP4 containing the origin of replication (oriP) and Epstein-Barr virus nuclear antigen 1 (EBNA-1). CMV promoter was replaced by subcloning the GIPP into pCEP4 to generate pGIPP/CEP4. Two recombinant EBV-based episomal vectors, pGIPP/GFP/CEP4 and pGIPP/PPI/CEP4, were constructed. pGIPP/GFP/CEP4 and pGIPP/PPI/CEP4 containing K-cell specific GIPP were co-transfected into STC-1. K-cell was isolated from the clonal expansion of the fluorescent cells selected by hygromycin treatment in STC-1, and were analyzed for the expression of glucokinase (GK) or transcription factors involved in pancreas development. K-cells concurrently transfected with pGIPP/PPI/CEP4 and pGIPP/GFP/CEP4 were analyzed for the transcripts of PPI by RT-PCR, and for the glucose dependent insulin expression by immunocytochemistry or insulin assay using ultra-sensitive rat-specific insulin ELISA kit. Result: STC-1 was stably-transfected with pGIPP/GFP/CEP4 along with pGIPP/PPI/CEP4. Genetically selected fluorescent K-cells expressed GK and transcription factors involved in pancreas development. And K-cells transfected with pGIPP/PPI/CEP4 contained detectable levels of PPI transcripts and showed glucose-dependent immunoreactive insulin
Databáze: OpenAIRE