title: Specific transgene expression in mouse pancreatic beta-cells under the control of the porcine insulin promoter.
abstract: The availability of regulatory sequences directing tissue-specific expression of transgenes in genetically modified mice and large animals is a prerequisite for the development of adequate models for human diseases. The rat insulin 2 gene (Ins2) promoter, widely used to achieve transgene expression in pancreatic beta-cells of mice, also directs expression to extrapancreatic tissues and performs poorly in isolated pancreatic islets of human, mouse, and pig. To evaluate whether the full 5' untranslated region (UTR) of the porcine insulin gene (INS) confers robust and specific expression in beta-cells we generated an expression cassette containing 1500bp of the porcine INS 5' UTR and the 3' UTR of the bovine growth hormone gene (GH). The cassette was designed to allow easy exchange of the sequences to be expressed and easy removal of the vector backbone from the expression cassette. To evaluate the properties of the cassette, we initially inserted a cDNA encoding human betacellulin, a growth factor known to affect structural and functional parameters of beta-cells. After confirming the functionality and specificity of the construct in vitro, transgenic mouse lines were generated by pronuclear DNA microinjection. Using RT-PCR, immunohistochemistry and immunofluorescence, we show that transgenic mice expressed human betacellulin exclusively in beta-cells. Confirming the proposed insulinotropic effect of betacellulin, transgenic mice showed improved glucose tolerance. We conclude that the newly designed expression cassette containing 1500bp of the porcine insulin promoter 5' UTR confers robust and specific transgene expression to beta-cells in vitro and in transgenic mice.
authors.affiliation: Chair for Molecular Animal Breeding and Biotechnology, Gene Center, LMU Munich, Feodor-Lynen-Str. 25, 81377 Munich, Germany.
authors.forename: Marjeta
authors.initials: M
authors.lastname: Grzech
authors.forename: Maik
authors.initials: M
authors.lastname: Dahlhoff
authors.forename: Nadja
authors.initials: N
authors.lastname: Herbach
authors.forename: Felix A
authors.initials: FA
authors.lastname: Habermann
authors.forename: Ingrid
authors.initials: I
authors.lastname: Renner-Müller
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Wanke
authors.forename: Heinrich
authors.initials: H
authors.lastname: Flaswinkel
authors.forename: Eckhard
authors.initials: E
authors.lastname: Wolf
authors.forename: Marlon R
authors.initials: MR
authors.lastname: Schneider
mesh_terms: D000818:Animals; D001483:Base Sequence; D066259:Betacellulin; D001786:Blood Glucose / Q000378:metabolism; D002417:Cattle; D005786:Gene Expression Regulation; D006801:Humans; D007328:Insulin / Q000235:genetics*; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000502:physiology*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D010641:Phenotype; D011401:Promoter Regions, Genetic; D051381:Rats; D013552:Swine; D014018:Tissue Distribution; D019076:Transgenes; D020506:Untranslated Regions / Q000235:genetics
chemical_list: C587851:BTC protein, human; D066259:Betacellulin; D001786:Blood Glucose; C587852:Btc protein, mouse; C587853:Btc protein, rat; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D020506:Untranslated Regions