Neurons Produce a Neuronal Cell Surface-Associated Chondroitin Sulfate Proteoglycan

• Published in: The Journal of neuroscience Vol. 18; no. 1; pp. 174 - 183
• Main Authors: Lander, Cynthia, Zhang, Hong, Hockfield, Susan
• Format: Journal Article
• Language: English
• Published: United States Soc Neuroscience 01.01.1998; Society for Neuroscience
• Subjects: Animals; Antibodies, Monoclonal; Antigens, Surface - immunology; Antigens, Surface - metabolism; Astrocytes - cytology; Brain Chemistry - physiology; Cells, Cultured; Cerebral Cortex - cytology; Chondroitin Sulfate Proteoglycans - immunology; Chondroitin Sulfate Proteoglycans - metabolism; Epitopes - analysis; Extracellular Matrix - chemistry; Neurons - cytology; Neurons - immunology; Neurons - metabolism; Rats; Rats, Sprague-Dawley
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/jneurosci.18-01-00174.1998

Monoclonal antibody Cat-315 recognizes a chondroitin sulfate proteoglycan (CSPG) expressed on the surface of subsets of neurons in many areas of the mammalian CNS (). The cell type-specific expression exhibited by the Cat-315 CSPG and other perineuronal net CSPGs imparts a distinct molecular surface identity to a neuron (Celio and Blumcke, 1994; Lander et al., 1997). The cell type(s) producing these surface-associated proteins and yielding this cellular diversity has remained in question. The expression of the Cat-315 CSPG in primary rat cortical cultures has permitted an examination of the cellular source of the Cat-315 antigen, as well as a determination of its spatial relationship to the neuronal surface. Live-cell labeling of primary neuronal cultures demonstrates that the Cat-315 CSPG is on the extracellular surface of neurons. Furthermore, extraction experiments demonstrate that the Cat-315 CSPG lacks a transmembrane domain and that the entire molecule is extracellular and, therefore, can be considered a constituent of brain extracellular matrix. Several lines of evidence indicate that neurons with cell surface staining produce the Cat-315 CSPG. First, neurons with cell surface staining also show intracellular Cat-315 immunoreactivity. Second, beta-xyloside or monensin, reagents that inhibit the synthesis and transport of CSPGs, increase intracellular Cat-315 immunoreactivity within neurons that express cell surface Cat-315 immunoreactivity. Third, double labeling with Cat-315 and a polyclonal antibody for the Golgi complex demonstrates a precise colocalization of the intracellular Cat-315 immunoreactivity with the Golgi. Together, these observations demonstrate that neurons contribute to the extracellular matrix of brain and that the Cat-315 CSPG is produced by the neurons that carry Cat-315 cell surface immunoreactivity.