Neurotractin/kilon promotes neurite outgrowth and is expressed on reactive astrocytes after entorhinal cortex lesion.
The IgLON subgroup of the immunoglobulin superfamily consists of four members that are thought to be important in neural cell-cell recognition. Here, we cloned and characterized the murine IgLON subgroup member neurotractin/kilon, in the context of brain development and axonal regeneration. Neurotractin/kilon was found to be upregulated during brain development and is expressed on neurites of primary hippocampal neurons. To elucidate a potential role for neurotractin/kilon during regeneration in the CNS, we performed lesions in the entorhinal cortex, and showed that the expression of neurotractin/kilon is induced on reactive astrocytes. Notably, the expression on reactive astrocytes appears specifically in the denervated outer molecular layer of the dentate gyrus, where regenerative axon sprouting occurs. In vitro assays demonstrated that neurotractin/kilon attracts hippocampal axons in the stripe assay and that astroglial neurotractin/kilon promotes neurite outgrowth. These results suggest a function for neurotractin/kilon as a trans-neural growth-promoting factor for outgrowing axons following hippocampal denervation.
Schäfer
Michael
M
Max-Delbrueck-Centre for Molecular Medicine, Developmental Neurobiology Group, D-13092 Berlin, Germany. schaefer@inmed.uni-mrs.fr
Bräuer
Anja U
AU
Savaskan
Nicolai E
NE
Rathjen
Fritz G
FG
Brümmendorf
Thomas
T
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D030161:Avian Proteins / Q000378:metabolism; D001930:Brain Injuries / Q000378:metabolism* / Q000503:physiopathology; D019556:COS Cells; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D002642:Chick Embryo; D002522:Chlorocebus aethiops; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D003714:Denervation; D018891:Dentate Gyrus / Q000166:cytology / Q000378:metabolism; D004195:Disease Models, Animal; D018728:Entorhinal Cortex / Q000293:injuries; D005911:Gliosis / Q000378:metabolism* / Q000503:physiopathology; D006133:Growth Substances / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009416:Nerve Regeneration / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D030161:Avian Proteins; D015816:Cell Adhesion Molecules, Neuronal; D018076:DNA, Complementary; D006133:Growth Substances; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C118293:Negr1 protein, rat; C120081:neurotractin protein, chicken; C000592528:NEGR1 protein, mouse