Nerve growth factor induces process formation in meningeal cells: implications for scar formation in the injured CNS.
Nerve growth factor (NGF) induces the differentiation and supports the survival of subpopulations of neurons in the PNS and CNS. Here we report that meningeal cells in the pia mater express immunoreactivity and mRNA for both known NGF receptors, the low-affinity receptor p75 and the tyrosine kinase receptor trkA. NGF induces rapid tyrosine phosphorylation of trkA in meningeal cells in vitro. NGF does not stimulate proliferation of primary meningeal cells but induces process outgrowth. p75- and trkA-immunoreactive meningeal cells with long processes, resembling NGF-treated cells in vitro, are abundant in the scar tissue that forms at spinal cord lesions in rat and cat. These data suggest that NGF, which is expressed at increased levels in the brain and spinal cord after lesions, may be involved in scar formation in the injured CNS.
Frisén
J
J
Department of Cell and Molecular Biology, Medical Nobel Institute, S-171 77 Stockholm, Sweden.
Risling
M
M
Korhonen
L
L
Zirrgiebel
U
U
Johansson
C B
CB
Cullheim
S
S
Lindholm
D
D
D000818:Animals; D002415:Cats; D002478:Cells, Cultured; D002921:Cicatrix / Q000473:pathology*; D005260:Female; D007150:Immunohistochemistry; D008578:Meninges / Q000187:drug effects* / Q000473:pathology; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D010766:Phosphorylation; D010841:Pia Mater / Q000187:drug effects / Q000293:injuries* / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis; D020800:Receptor, Nerve Growth Factor; D020917:Receptor, trkA; D017475:Receptors, Nerve Growth Factor / Q000032:analysis; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
D009414:Nerve Growth Factors; D011518:Proto-Oncogene Proteins; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA