title: GDNF Overexpression from the Native Locus Reveals its Role in the Nigrostriatal Dopaminergic System Function.
abstract: Degeneration of nigrostriatal dopaminergic system is the principal lesion in Parkinson's disease. Because glial cell line-derived neurotrophic factor (GDNF) promotes survival of dopamine neurons in vitro and in vivo, intracranial delivery of GDNF has been attempted for Parkinson's disease treatment but with variable success. For improving GDNF-based therapies, knowledge on physiological role of endogenous GDNF at the sites of its expression is important. However, due to limitations of existing genetic model systems, such knowledge is scarce. Here, we report that prevention of transcription of Gdnf 3'UTR in Gdnf endogenous locus yields GDNF hypermorphic mice with increased, but spatially unchanged GDNF expression, enabling analysis of postnatal GDNF function. We found that increased level of GDNF in the central nervous system increases the number of adult dopamine neurons in the substantia nigra pars compacta and the number of dopaminergic terminals in the dorsal striatum. At the functional level, GDNF levels increased striatal tissue dopamine levels and augmented striatal dopamine release and re-uptake. In a proteasome inhibitor lactacystin-induced model of Parkinson's disease GDNF hypermorphic mice were protected from the reduction in striatal dopamine and failure of dopaminergic system function. Importantly, adverse phenotypic effects associated with spatially unregulated GDNF applications were not observed. Enhanced GDNF levels up-regulated striatal dopamine transporter activity by at least five fold resulting in enhanced susceptibility to 6-OHDA, a toxin transported into dopamine neurons by DAT. Further, we report how GDNF levels regulate kidney development and identify microRNAs miR-9, miR-96, miR-133, and miR-146a as negative regulators of GDNF expression via interaction with Gdnf 3'UTR in vitro. Our results reveal the role of GDNF in nigrostriatal dopamine system postnatal development and adult function, and highlight the importance of correct spatial expression of GDNF. Furthermore, our results suggest that 3'UTR targeting may constitute a useful tool in analyzing gene function.
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Anmol
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kopra
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Kärt
authors.initials: K
authors.lastname: Varendi
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Lauriina L
authors.initials: LL
authors.lastname: Porokuokka
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Panhelainen
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Kuure
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Pepin
authors.initials: P
authors.lastname: Marshall
authors.affiliation: Department of Histology and Cell Biology, Umeå University, Umeå, Sweden.
authors.forename: Nina
authors.initials: N
authors.lastname: Karalija
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Mari-Anne
authors.initials: MA
authors.lastname: Härma
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Carolina
authors.initials: C
authors.lastname: Vilenius
authors.affiliation: Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Kersti
authors.initials: K
authors.lastname: Lilleväli
authors.affiliation: Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Triin
authors.initials: T
authors.lastname: Tekko
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
authors.forename: Jelena
authors.initials: J
authors.lastname: Mijatovic
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
authors.forename: Nita
authors.initials: N
authors.lastname: Pulkkinen
authors.affiliation: Department of Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
authors.forename: Madis
authors.initials: M
authors.lastname: Jakobson
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Maili
authors.initials: M
authors.lastname: Jakobson
authors.affiliation: Department of Biochemistry and Developmental Biology, Institute of Biomedicine, University of Helsinki, Helsinki, Finland.
authors.forename: Roxana
authors.initials: R
authors.lastname: Ola
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Erik
authors.initials: E
authors.lastname: Palm
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Maria
authors.initials: M
authors.lastname: Lindahl
authors.affiliation: Department of Histology and Cell Biology, Umeå University, Umeå, Sweden.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Strömberg
authors.affiliation: Neuroscience Center and Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Vootele
authors.initials: V
authors.lastname: Võikar
authors.affiliation: Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland.
authors.forename: T Petteri
authors.initials: TP
authors.lastname: Piepponen
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Mart
authors.initials: M
authors.lastname: Saarma
authors.affiliation: Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
authors.forename: Jaan-Olle
authors.initials: JO
authors.lastname: Andressoo
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000633:toxicity; D000818:Animals; D002490:Central Nervous System / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004298:Dopamine / Q000235:genetics* / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000378:metabolism* / Q000473:pathology; D018507:Gene Expression Regulation, Developmental; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D007668:Kidney / Q000254:growth & development / Q000378:metabolism; D051379:Mice; D017072:Neostriatum / Q000378:metabolism / Q000473:pathology; D018696:Neuroprotective Agents / Q000378:metabolism; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D013378:Substantia Nigra / Q000378:metabolism* / Q000473:pathology
chemical_list: C495040:Gdnf protein, mouse; D051100:Glial Cell Line-Derived Neurotrophic Factor; D018696:Neuroprotective Agents; C067713:lactacystin; D004298:Dopamine; D000111:Acetylcysteine