title: Repeatable, Inducible Micro-RNA-Based Technology Tightly Controls Liver Transgene Expression.
abstract: Inducible systems for gene expression emerge as a new class of artificial vectors offering temporal and spatial exogenous control of gene expression. However, most inducible systems are less efficient in vivo and lack the target-organ specificity. In the present study, we have developed and optimized an oligonucleotide-based inducible system for the in vivo control of transgenes in the liver. We generated a set of simple, inducible plasmid-vectors based on the addition of four units of liver-specific miR-122 target sites to the 3'untranslated region of the gene of interest. Once the vector was delivered into hepatocytes this modification induced a dramatic reduction of gene expression that could be restored by the infusion of an antagomir for miR-122. The efficiency of the system was tested in vivo, and displayed low background and strong increase in gene expression upon induction. Moreover, gene expression was repeatedly induced even several months after the first induction showing no toxic effect in vivo. By combining tissue-specific control elements with antagomir treatment we generated, optimized and validated a robust inducible system that could be used successfully for in vivo experimental models requiring tight and cyclic control of gene expression.
authors.affiliation: 1] Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden [2] Department of Pharmaceutical Technology and Biopharmaceutics, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania [3] Department of Oncology and Pathology, Cancer Center Karolinska, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Iulian I
authors.initials: II
authors.lastname: Oprea
authors.affiliation: Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden.
authors.forename: Joana R
authors.initials: JR
authors.lastname: Viola
authors.affiliation: Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden.
authors.forename: Pedro M D
authors.initials: PM
authors.lastname: Moreno
authors.affiliation: Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden.
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Simonson
authors.affiliation: Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sergey
authors.initials: S
authors.lastname: Rodin
authors.affiliation: Eurogentec S.A., Seraing, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Teller
authors.affiliation: Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Karl
authors.initials: K
authors.lastname: Tryggvason
authors.affiliation: Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden.
authors.forename: Karin E
authors.initials: KE
authors.lastname: Lundin
authors.affiliation: Department of Oncology and Pathology, Cancer Center Karolinska, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Leonard
authors.initials: L
authors.lastname: Girnita
authors.affiliation: Department of Laboratory Medicine, Clinical Research Center, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, Sweden.
authors.forename: Carl Inge Edvard
authors.initials: CI
authors.lastname: Smith