Overexpression of glial cell line-derived neurotrophic factor induces genes regulating migration and differentiation of neuronal progenitor cells☆
Introduction
The glial cell line-derived neurotrophic factor (GDNF) is vital to the development and maintenance of neural tissues. It is a distant member of the TGFβ-superfamily, which comprises an expanding list of multifunctional proteins serving as regulators of cell proliferation and differentiation [1]. Recently, the neuronal cell adhesion molecule (NCAM) has been identified as a receptor for GDNF. Functional assays of Schwann cell migration and axon growth of central nervous system (CNS) neurons suggest physiological significance for this newly discovered pathway [2]. However, the effector proteins of GDNF signaling still remain to be elucidated. In this paper, we highlight new genes, which are influenced by GDNF signaling.
In normal development, GDNF promotes survival of sympathetic, parasympathetic [3], and spinal motorneurons [4]. It even promotes regeneration of spinal motor neurons after spinal cord injury [5]. In Hirschsprung's disease, several mutations of signaling components of the known GDNF-signaling pathway were found to cause migration deficits of enteric ganglia [6]. GDNF was first identified as a survival factor for dopaminergic neurons of the midbrain [7]. These neurons degenerate in Parkinson's disease (PD), and treatment of animal models and PD patients with exogenous GDNF promotes functional recovery [8], [9]. However, GDNF is a large molecule that must be delivered directly to the brain rather than given peripherally [10]. When this is done, it can support the survival and outgrowth of dopaminergic neurons following transplantation [11]. Additionally, GDNF added to cell suspensions of embryonic ventral mesencephalic tissue improves the survival of dopaminergic neurons following grafting into the striatum [12]. Intermittent injections of GDNF near intrastriatally transplanted, fetal nigral cell suspension grafts have similar effects on survival and neurite outgrowth of transplanted dopaminergic neurons [13]. How these effects precisely arise and which genes and pathways are involved is still unknown.
Another strategy for the delivery of trophic molecules to transplanted dopaminergic neurons is to cograft cells that endogenously produce trophic factors [14]. Several studies have taken advantage of neuronal stem or progenitor cells for this purpose [15], [16]. One of the best-characterized progenitor cell lines used for transplantation and differentiation studies in rodents is the ST14A cell line, originally established by Cattaneo et al. [17]. These researchers isolated striatal progenitor cells from embryonic day 14 rats and immortalized the cells by retroviral transfection of a temperature-sensitive mutant of the SV40 large T-antigen (SV40-T). ST14A cells remain properties of neural progenitor cells, including the expression of nestin and the capability to differentiate into MAP2-positive cells [18]. The temperature-dependent oncogene expression allows controlled growth of mature or neurotrophin-producing ST14A cells in vitro [19], [20] and in vivo, thereby supplying a tool for in vitro expansion (33°C) and in vivo differentiation (39°C) [21]. The inactivation of the SV40-T at 39°C corresponds to the brain temperature of the grafted rodents. Several studies have shown that the transplantation of progenitor cells into embryonic or adult brain leads to a differentiation into mature neurons and glial cells [17], [22]. However, significant improvement of the neurological deficits in the PD model was not seen. On the other hand, ST14A cells can be easily modified genetically and therefore used as vehicle for endogenous overproduction of neurotrophins [19], [20]. In addition, the effects of endogenous overproduction of neurotrophic factors on survival, migration, and differentiation processes can easily be investigated with these cells.
In two recent studies, we showed that the overproduction of ciliary neurotrophic factor (CNTF) leads to an improved stress response of neuronal progenitor cells during the early stages of differentiation [19], [20]. Here, we identified 43 genes exclusively involved in GDNF-dependent signaling, which are directly or indirectly involved in the differentiation and migration of neuronal progenitor cells. The knowledge of these GDNF-regulated genes will open new possibilities for directly influencing differentiation and developmental processes, enabling the treatment of neurodegenerative diseases by modulating precisely these new effectors.
Section snippets
Cell culture
ST14A cells were cultured as monolayers in Dulbecco's MEM-Glutamax I (DMEM) supplemented with 50 IU/ml penicillin, 60 μg/ml streptomycin and 10% inactivated fetal bovine serum (FBS) (all solutions from GibcoBRL, Life Technologies) in humidified atmosphere of 33°C and 39°C, respectively [21].
Cloning of the rat GDNF
Total RNA was extracted from rat brain according to standard protocols. After reverse transcription (Superscript™, GibcoBRL), an aliquot of the resulting cDNA was PCR-amplified with rat GDNF-specific primers
Results
Our goal was to identify genes that are exclusively regulated by GDNF. We used our previous expression data from native and CNTF-transfected ST14A cells and compared those with the expression values of the GDNF-overexpressing cells [20]. The signal values were normalized to the expression of native ST14A cells at each timepoint and at 33°C. Expression changes of native, CNTF-, and GDNF-transfected ST14A cells were then compared. By doing so, we gained information about temperature-dependent
Discussion
In this study, we investigated the effects of GDNF overexpression in striatal precursor cells with special emphasis on functional pathways and common mechanisms of GDNF signaling during neuronal development and differentiation. For this purpose, we primarily compared the gene expression changes of GDNF-transfected ST14A cells during the early stages of temperature-induced differentiation with the result of our recent study in non-transfected and in CNTF-transfected ST14A cells [20]. By this
Acknowledgements
We thank K. Biedermann, N. Deinet and J. Kropp for their technical support and Prof. Lary C. Walker (Yerkes Institute, Emory Univerity, Atlanta, USA) as well as Prof. Mart Saarma (Institute of Biotechnology, University of Helsinki, Finland) for helpful comments on the manuscript. The work was supported by the Bundesministerium für Bildung und Forschung (NBL3 FKZ01-ZZ-0108).
References (76)
- et al.
The neural cell adhesion molecule NCAM is an alternative signaling receptor for GDNF family ligands
Cell
(2003) - et al.
Glial cell line-derived neurotrophic factor does not enter normal mouse brain
Neurosci. Lett.
(2003) - et al.
Transplantation of human neural progenitor cells into the neonatal rat brain: extensive migration and differentiation with long-distance axonal projections
Exp. Neurol.
(2002) - et al.
Conditionally immortalized neural progenitor cell lines integrate and differentiate after grafting to the adult rat striatum. A combined autoradiographic and electron microscopic study
Brain Res.
(1996) - et al.
A short term analysis of the behaviour of conditionally immortalized neuronal progenitors and primary neuroepithelial cells implanted into the fetal rat brain
Brain Res., Dev. Brain Res.
(1994) - et al.
Gene expression profiling of the nervous system in murine experimental autoimmune encephalomyelitis
Brain
(2001) - et al.
Doublecortin, a stabilizer of microtubules
Hum. Mol. Genet.
(1999) - et al.
Dual role of Fyn in the regulation of FAK+6,7 by cannabinoids in hippocampus
J. Biol. Chem.
(2001) - et al.
High-frequency synaptic stimulation induces association of fyn and c-src to distinct phosphorylated components
NeuroReport
(2000) - et al.
Rapid induction of dendritic spine morphogenesis by trans-synaptic ephrinB-EphB receptor activation of the Rho-GEF kalirin
Neuron
(2003)
The receptor tyrosine kinase EphB2 regulates NMDA-dependent synaptic function
Neuron
EphB forward signaling controls directional branch extension and arborization required for dorsal-ventral retinotopic mapping
Neuron
EphB receptors regulate dendritic spine development via intersectin, Cdc42 and N-WASP
Nat. Neurosci.
Diminished Sonic hedgehog signaling and lack of floor plate differentiation in Gli2 mutant mice
Development
The essential role of Cited2, a negative regulator for HIF-1alpha, in heart development and neurulation
Proc. Natl. Acad. Sci. U. S. A.
Vascular endothelial growth factor (VEGF) stimulates neurogenesis in vitro and in vivo
Proc. Natl. Acad. Sci. U. S. A.
Cellular diversification in the vertebrate retina
Curr. Opin. Genet. Dev.
Neurogenic genes and vertebrate neurogenesis
Curr. Opin. Neurobiol.
Transient Notch activation initiates an irreversible switch from neurogenesis to gliogenesis by neural crest stem cells
Cell
The expression and function of Notch pathway genes in the developing rat eye
J. Neurosci.
Radial glial identity is promoted by Notch1 signaling in the murine forebrain
Neuron
Sequential signaling through Notch1 and erbB receptors mediates radial glia differentiation
J. Neurosci.
Signaling to and from radial glia
Glia
Identification of cortexin: a novel, neuron-specific, 82-residue membrane protein enriched in rodent cerebral cortex
J. Neurochem.
Notch1 and Notch3 instructively restrict bFGF-responsive multipotent neural progenitor cells to an astroglial fate
Neuron
Mode of cell migration to the superficial layers of fetal monkey neocortex
J. Comp. Neurol.
DCX in PC12 cells: CREB-mediated transcription and neurite outgrowth
Hum. Mol. Genet.
Stages of synapse development defined by dependence on F-actin
J. Neurosci.
Hirschsprung disease is linked to defects in neural crest stem cell function
Science
The TGF-beta superfamily: new members, new receptors, and new genetic tests of function in different organisms
Genes Dev.
Peripheral expression and biological activities of GDNF, a new neurotrophic factor for avian and mammalian peripheral neurons
J. Cell Biol.
Glial cell line-derived neurotrophic factor (GDNF), a new neurotrophic factor for motoneurones
NeuroReport
Functional regeneration of sensory axons into the adult spinal cord
Nature
Enteric nervous system: development and developmental disturbances—Part 2
Pediatr. Dev. Pathol.
GDNF: a glial cell line-derived neurotrophic factor for midbrain dopaminergic neurons
Science
Functional recovery in parkinsonian monkeys treated with GDNF
Nature
Direct brain infusion of glial cell line-derived neurotrophic factor in Parkinson disease
Nat. Med.
Effects of glial cell line-derived neurotrophic factor on developing and mature ventral mesencephalic grafts in oculo
Exp. Neurol.
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Supplementary data associated with this article can be found at doi: 10.1016/S0014-4827(04)00174-0.