title: Generation of transgenic fibroblasts expressing pancreas‑specific and doxycycline-inducible ICER Iγ for the establishment of a porcine model of human diabetes mellitus.
abstract: Inducible cyclic AMP (cAMP) early repressor (ICER) Iγ acts as an endogenous inhibitor and disrupts the transcriptional regulation of cAMP response element binding protein (CREBP) responsive genes. Since the overexpression of ICER Iγ induces severe diabetes in a transgenic mouse model, with characteristics similar to human diabetes mellitus, an ICER Iγ construct containing an adjustable pancreas tissue specific promoter was utilized in the present study. Using the human insulin promoter region, a doxycycline (dox)‑inducible ICER Iγ expression system was established using the tetracycline (tet)-controlled transactivator (tTA) with a TA response element (TRE) promoter. A unitary tet-on system that combined a tet-on activator cassette was also developed and was controlled by the human insulin promoter with a responder cassette containing genes encoding ICER Iγ regulated by the TRE promoter. To determine whether dox-enhanced ICER Iγ expression affected insulin production, the unitary tet-on ICER Iγ vector was introduced into a mouse pancreatic β-cell line and then the cells were treated with 0.1-1 mg/ml dox. The results revealed a robust increase in ICER Iγ expression and decreased insulin production. Therefore, this in vitro system may be useful for studying human diabetes mellitus and pre-diabetes using tissue-specific promoters and a dox-inducible transgene. In addition, porcine transgenic fibroblasts containing dox-inducible ICER Iγ were generated. These fibroblasts may serve as a cell source for somatic cell nuclear transfer to generate a porcine model of human diabetes mellitus.
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kang
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors.forename: Eui-Man
authors.initials: EM
authors.lastname: Jung
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors.forename: Eui-Ju
authors.initials: EJ
authors.lastname: Hong
authors.affiliation: Laboratory of Veterinary Embryology and Biotechnology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors.forename: Sang-Hwan
authors.initials: SH
authors.lastname: Hyun
authors.affiliation: SooAm Biotech Research Foundation, Seoul 137-851, Republic of Korea.
authors.forename: Woo-Suk
authors.initials: WS
authors.lastname: Hwang
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
authors.forename: Eui-Bae
authors.initials: EB
authors.lastname: Jeung
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D051786:Cyclic AMP Response Element Modulator / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D004318:Doxycycline / Q000633:toxicity*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects*; D005822:Genetic Vectors / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D020218:Response Elements; D013552:Swine; D015534:Trans-Activators / Q000235:genetics
chemical_list: D007328:Insulin; D012333:RNA, Messenger; D015534:Trans-Activators; D051786:Cyclic AMP Response Element Modulator; D004318:Doxycycline