title: A rapid and dynamic regulation of GDNF-family ligands and receptors correlate with the developmental dependency of cutaneous sensory innervation.
abstract: Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) are members of the transforming growth factor-beta family and have been shown to elicit neurotrophic effects upon several classes of neurons including dopaminergic neurons, motoneurons, parasympathetic, sympathetic as well as primary sensory neurons. However, there is little information available on their roles in cutaneous innervation. Herein, we have studied the regulation of gdnf, ntn and the GDNF family receptors and examined their role in the development of facial cutaneous innervation in GDNF mutant mice. A dynamic spatial and temporal regulation of gdnf, ntn and their ligand binding receptors within the follicle-sinus complex correlate with development of distinct subclasses of sensory nerve endings. Furthermore, development of NGF-dependent myelinated mechanoreceptors, i.e. reticular and transverse lanceolate endings also require GDNF during ending formation and maintenance. In addition, ligand and receptor association seems to be intricately linked to a local Schwann cell-axon interaction essential for sensory terminal formation. Our results suggests that functionally specified nerve endings depend on different GDNF family members and that in contrast to neurotrophins, this family of neurotrophic factors may be acting at local sites of terminal Schwann cell-axon growth cone interactions and that they collaborate with neurotrophins by supporting the same populations of neurons but at different times in development.
authors.affiliation: Laboratory of Molecular Neurobiology, MBB, Karolinska Institute, S171 77 Stockholm, Sweden. Bengt@cajal.mbb.ki.se
authors.forename: B T
authors.initials: BT
authors.lastname: Fundin
authors.forename: A
authors.initials: A
authors.lastname: Mikaels
authors.forename: H
authors.initials: H
authors.lastname: Westphal
authors.forename: P
authors.initials: P
authors.lastname: Ernfors
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D029721:Drosophila Proteins; D005145:Face / Q000294:innervation; D018507:Gene Expression Regulation, Developmental; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D018859:Hair Follicle / Q000294:innervation; D008562:Membrane Glycoproteins; D051379:Mice; D008817:Mice, Mutant Strains; D009186:Myelin Sheath / Q000502:physiology; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D016501:Neurites / Q000378:metabolism; D009475:Neurons, Afferent / Q000502:physiology*; D051101:Neurturin; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor; D012583:Schwann Cells / Q000378:metabolism; D012867:Skin / Q000294:innervation*; D012668:Trigeminal Ganglion / Q000378:metabolism; D014738:Vibrissae / Q000294:innervation
chemical_list: D029721:Drosophila Proteins; C495040:Gdnf protein, mouse; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D051101:Neurturin; C495056:Nrtn protein, mouse; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D017475:Receptors, Nerve Growth Factor; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila