A Contactin–Receptor‐Like Protein Tyrosine Phosphatase β Complex Mediates Adhesive Communication Between Astroglial Cells and Gonadotrophin‐Releasing Hormone Neurones
- 31 July 2007
- journal article
- Published by Wiley in Journal of Neuroendocrinology
- Vol. 19 (11), 847-859
- https://doi.org/10.1111/j.1365-2826.2007.01597.x
Abstract
Although it is well established that gonadotrophin-releasing hormone (GnRH) neurones and astrocytes maintain an intimate contact throughout development and adult life, the cell-surface molecules that may contribute to this adhesiveness remain largely unknown. In the peripheral nervous system, the glycosylphosphatidyl inositol (GPI)-anchored protein contactin is a cell-surface neuronal protein required for axonal-glial adhesiveness. A glial transmembrane protein recognised by neuronal contactin is receptor-like protein tyrosine phosphatase beta (RPTP beta), a phosphatase with structural similarities to cell adhesion molecules. In the present study, we show that contactin, and its preferred in cis partner Caspr1, are expressed in GnRH neurones. We also show that the RPTP beta mRNA predominantly expressed in hypothalamic astrocytes encodes an RPTP beta isoform (short RPTP beta) that uses its carbonic anhydrase (CAH) extracellular subdomain to interact with neuronal contactin. Immunoreactive contactin is most abundant in GnRH nerve terminals projecting to both the organum vasculosum of the lamina terminalis and median eminence, implying GnRH axons as an important site of contactin-dependent cell adhesiveness. GT1-7 immortalised GnRH neurones adhere to the CAH domain of RPTPbeta, and this adhesiveness is blocked when contactin GPI anchoring is disrupted or contactin binding capacity is immunoneutralised, suggesting that astrocytic RPTP beta interacts with neuronal contactin to mediate glial-GnRH neurone adhesiveness. Because the abundance of short RPTP beta mRNA increases in the female mouse hypothalamus (but not in the cerebral cortex) before puberty, it appears that an increased interaction between GnRH axons and astrocytes mediated by RPTP beta-contactin is a dynamic mechanism of neurone-glia communication during female sexual development.Keywords
This publication has 63 references indexed in Scilit:
- Expression of Three Gene Families Encoding Cell–Cell Communication Molecules in the Prepubertal Nonhuman Primate HypothalamusJournal of Neuroendocrinology, 2005
- Phosphacan Short Isoform, a Novel Non-proteoglycan Variant of Phosphacan/Receptor Protein Tyrosine Phosphatase-β, Interacts with Neuronal Receptors and Promotes Neurite OutgrowthJournal of Biological Chemistry, 2003
- Multi-ligand interactions with receptor-like protein tyrosine phosphatase β: implications for intercellular signalingTrends in Biochemical Sciences, 1998
- Expression of polypeptide variants of receptor-type protein tyrosine phosphatase ?: The secreted form, phosphacan, increases dramatically during embryonic development and modulates glial cell behavior in vitroJournal of Neuroscience Research, 1996
- Glial Ensheathment of GnRH Neurons in Pubertal Female Rhesus MacaquesJournal of Neuroendocrinology, 1995
- Luteinizing hormone-releasing hormone terminals in the median eminence of rats undergo dramatic changes after gonadectomy, as revealed by electron microscopic image analysisEndocrinology, 1994
- Developmental Expression of the Genes Encoding Transforming Growth Factor Alpha and Its Receptor in the Hypothalamus of Female Rhesus MacaquesNeuroendocrinology, 1994
- Axonal Glycoproteins with Immunoglobulin‐ and Fibronectin Type III‐Related Domains in Vertebrates: Structural Features, Binding Activities, and Signal TransductionJournal of Neurochemistry, 1993
- Monoclonal Antibodies to Luteinizing Hormone-Releasing Hormone: Production, Characterization, and Immunocytochemical Application1Biology of Reproduction, 1991
- MATURATION OF THE INHIBITORY FEEDBACK ACTION OF OESTROGEN ON FOLLICLE-STIMULATING HORMONE SECRETION IN THE IMMATURE FEMALE RAT: A ROLE FOR ALPHA-FOETOPROTEINJournal of Endocrinology, 1979