Glial Cell Line-Derived Neurotrophic Factor and Neurturin Inhibit Neurite Outgrowth and Activate RhoA through GFRα2b, an Alternatively Spliced Isoform of GFRα2

Abstract

The glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) belong to a structurally related family of neurotrophic factors. NTN exerts its effect through a multicomponent receptor system consisting of the GDNF family receptor ␣2 (GFR␣2), RET, and/or NCAM (neural cell adhesion molecule). GFR␣2 is alternatively spliced into at least three isoforms (GFR␣2a, GFR␣2b, and GFR␣2c). It is currently unknown whether these isoforms share similar functional and biochemical properties. Using highly specific and sensitive quantitative real-time PCR, these isoforms were found to be expressed at comparable levels in various regions of the human brain. When stimulated with GDNF and NTN, both GFR␣2a and GFR␣2c, but not GFR␣2b, promoted neurite outgrowth in transfected Neuro2A cells. These isoforms showed ligand selectivity in MAPK (mitogen-activated protein kinase) [ERK1/2 (extracellular signalregulated kinase 1/2)] and Akt signaling. In addition, the GFR␣2 isoforms regulated different early-response genes when stimulated with GDNF or NTN. In coexpression studies, GFR␣2b was found to inhibit ligand-induced neurite outgrowth by GFR␣2a and GFR␣2c. Stimulation of GFR␣2b also inhibited the neurite outgrowth induced by GFR␣1a, another member of the GFR␣. Furthermore, activation of GFR␣2b inhibited neurite outgrowth induced by retinoic acid and activated RhoA. Together, these data suggest a novel paradigm for the regulation of growth factor signaling and neurite outgrowth via an inhibitory splice variant of the receptor. Thus, depending on the expressions of specific GFR␣2 receptor spliced isoforms, GDNF and NTN may promote or inhibit neurite outgrowth through the multicomponent receptor complex.

PRMT1 and PRMT8 Regulate Retinoic Acid-Dependent Neuronal Differentiation with Implications to Neuropathology

“…D). We validated Phox2b (Paired‐Like Homeobox 2b), an important transcription factor of neural specification and Gfra2 (GDNF Family Receptor Alpha), a regulator of neurite outgrowth by RT‐qPCR (Fig. E).…”

Patient Mutations of the Intellectual Disability Gene KDM5C Downregulate Netrin G2 and Suppress Neurite Growth in Neuro2a Cells

“…These are mouse neuroblastoma cells that have gained increasing popularity in recent years for functionality studies, including analysis of guidance cues (e.g. Netrins, Slits, Ephrins, and Semaphorins) and cell adhesion molecules as well as intracellular signaling pathways, determining the contributions of these genes to neuronal differentiation, axon/dendrite growth, and cell migration (Goshima et al, 1993, Nakata and Troy, 2005, Jankowski et al, 2006, Dasgupta and Milbrandt, 2007, Shin et al, 2007, Yoong and Too, 2007, Schwaibold and Brandt, 2008, Chen et al, 2011, Hagiyama et al, 2011, Li et al, 2011, Takahashi et al, 2012, Ito et al, 2014). In these studies, the gene of interest is typically mutated, knocked down, or over-expressed in N2a cells, taking advantage of the high efficiency of plasmid transfection in these cells.…”

Gene expression profile analysis of genes in rat hippocampus from antidepressant treated rats using DNA microarray

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