title: Spatiotemporally limited BDNF and GDNF overexpression rescues motoneurons destined to die and induces elongative axon growth.
abstract: Axonal injury close to cell bodies of motoneurons induces the death of the vast majority of affected cells. Neurotrophic factors, such as brain derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF), delivered close to the damaged motor pool in a non-regulated manner induce good survival of injured motoneurons and sprouting of their axons but fail to induce functional reinnervation. To avoid these drawbacks of high levels of neurotrophic expression, we devised an ex vivo gene therapy system to induce transient expression of BDNF/GDNF in transfected rat adipose tissue-derived stem cells (rASCs) which were grafted around the reimplanted ventral root, embedded in collagen gel. Strong BDNF/GDNF expression was induced in vitro in the first days after transfection with a significant decline in expression 10-14 days following transfection. Numerous axons of injured motoneurons were able to enter the reimplanted root following reimplantation and BDNF or GDNF treatment (192±17 SEM vs 187±12 SEM, respectively) and produce morphological and functional reinnervation. Treatment with a combined cell population (BDNF+GDNF-transfected rASCs) induced slightly improved reinnervation (247±24 SEM). In contrast, only few motoneurons regenerated their axons in control animals (63±4 SEM) which received untransfected cells. The axons of surviving motoneurons showed elongative growth typical of regenerative axons, without aberrant growth or coil formation of sprouting axons. These findings provide evidence that damaged motoneurons require limited and spatially directed amounts of BDNF and GDNF to support their survival and regeneration. Moreover, neurotrophic support appears to be needed only for a critical period of time not longer than for two weeks after injury.
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology at the Research Centre for Traumatology of the Austrian Workers, Donaueschingenstr, 13, A-1200 Vienna, Austria; Department for Trauma Surgery, Medical University Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
authors.forename: Gholam
authors.initials: G
authors.lastname: Pajenda
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology at the Research Centre for Traumatology of the Austrian Workers, Donaueschingenstr, 13, A-1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration and Compensation Board (AUVA), Donaueschingenstr, 13, A-1200 Vienna, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Hercher
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Márton
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary.
authors.forename: Krisztián
authors.initials: K
authors.lastname: Pajer
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology at the Research Centre for Traumatology of the Austrian Workers, Donaueschingenstr, 13, A-1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration and Compensation Board (AUVA), Donaueschingenstr, 13, A-1200 Vienna, Austria.
authors.forename: Georg A
authors.initials: GA
authors.lastname: Feichtinger
authors.affiliation: Department of Anatomy, Histology and Embryology, Faculty of Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary.
authors.forename: József
authors.initials: J
authors.lastname: Maléth
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology at the Research Centre for Traumatology of the Austrian Workers, Donaueschingenstr, 13, A-1200 Vienna, Austria; Austrian Cluster for Tissue Regeneration and Compensation Board (AUVA), Donaueschingenstr, 13, A-1200 Vienna, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Redl
authors.affiliation: Ludwig Boltzmann Institute for Experimental and Clinical Traumatology at the Research Centre for Traumatology of the Austrian Workers, Donaueschingenstr, 13, A-1200 Vienna, Austria; Department of Anatomy, Histology and Embryology, Faculty of Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary; 1st Department of Internal Medicine, Albert Szent-Györgyi Clinical Centre, University of Szeged, Hungary. Electronic address: nogradi.antal@med.u-szeged.hu.
authors.forename: Antal
authors.initials: A
authors.lastname: Nógrádi
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000578:Amidines; D000818:Animals; D001369:Axons / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D004622:Embryo, Mammalian; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology; D005786:Gene Expression Regulation; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D008124:Locomotion / Q000502:physiology; D008297:Male; D051379:Mice; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000628:therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000502:physiology
chemical_list: D000578:Amidines; D019208:Brain-Derived Neurotrophic Factor; D051100:Glial Cell Line-Derived Neurotrophic Factor; C031455:diamidino compound 253-50
keywords: Adipose tissue-derived stem cells; Axonal growth; BDNF; GDNF; Reinnervation; Transfection; Ventral root avulsion