Nerve Growth Factor Induces Process Formation in Meningeal Cells: Implications for Scar Formation in the Injured CNS
- Jonas Frisén1,
- Mårten Risling2,
- Laura Korhonen3,
- Ute Zirrgiebel4,
- Clas B. Johansson1,2,
- Staffan Cullheim2, and
- Dan Lindholm3
- 1Department of Cell and Molecular Biology, Medical Nobel Institute, and
- 2Department of Neuroscience, Karolinska Institute, S-171 77 Stockholm, Sweden,
- 3Department of Developmental Neuroscience, Biomedical Center, S-751 23 Uppsala, Sweden, and
- 4Brain Tumor Research Centre, Montreal Neurological Institute, Montreal, PQ, Canada, H3A 2B4
Abstract
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.
- Received March 25, 1998.
- Revision received May 13, 1998.
- Accepted May 13, 1998.
- Copyright © 1998 Society for Neuroscience
