title: Establishment and characterization of a transgenic mouse model for in vivo imaging of Bmp4 expression in the pancreas.
abstract: Type-2 diabetes results from the development of insulin resistance and a concomitant impairment of insulin secretion. Bone morphogenetic protein 4 (Bmp4)-Bmp receptor 1A signaling in β cells has recently been reported to be required for insulin production and secretion. In addition, Bmp4 blocks the differentiation and promotes the expansion of endocrine progenitor cells. Bmp4 therefore regulates the maintenance of homeostasis in the pancreas. In this study, we constructed a reporter plasmid carrying 7-kb enhancer and promoter region of the Bmp4 gene upstream of the firefly luciferase gene. We used this construct to produce transgenic mice by pro-nuclear microinjection, for subsequent in vivo monitoring of Bmp4 expression. The bioluminescent signal was detected mainly in the pancreas in three independent lines of transgenic mice. Furthermore, the bioluminescent signal was enhanced in association with the autophagy response to 24-h fasting. These results suggest that pancreatic expression of Bmp4 is involved in responding to the physiological environment, including through autophagy. These mouse models represent useful tools for toxicological screening, and for investigating the mechanisms responsible for pancreatic Bmp4 functions in vivo, with relevance to improving our understanding of pancreatic diseases.
authors.affiliation: Division of Molecular Biology, School of Life Sciences, Faculty of Medicine, Tottori University, Yonago, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Yasunaga
authors.forename: Nao
authors.initials: N
authors.lastname: Oumi
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Osaki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kazuki
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Oshimura
authors.forename: Kenzo
authors.initials: K
authors.lastname: Sato
mesh_terms: D000818:Animals; D015153:Blotting, Western; D055415:Bone Morphogenetic Protein 4 / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction
chemical_list: C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D008156:Luciferases