Abstract
In our previous study, the CS-56 antibody, which recognizes a chondroitin sulfate moiety, labeled a subset of adult brain astrocytes, yielding a patchy extracellular matrix pattern. To explore the molecular nature of CS-56-labeled glycoproteins, we purified glycoproteins of the adult mouse cerebral cortex using a combination of anion-exchange, charge-transfer, and size-exclusion chromatographies. One of the purified proteins was identified as tenascin-R (TNR) by mass spectrometric analysis. When we compared TNR mRNA expression patterns with the distribution patterns of CS-56-positive cells, TNR mRNA was detected in CS-56-positive astrocytes. To examine the functions of TNR in astrocytes, we first confirmed that cultured astrocytes also expressed TNR protein. TNR knockdown by siRNA expression significantly reduced glutamate uptake in cultured astrocytes. Furthermore, expression of mRNA and protein of excitatory amino acid transporter 1 (GLAST), which is a major component of astrocytic glutamate transporters, was reduced by TNR knockdown. Our results suggest that TNR is expressed in a subset of astrocytes and contributes to glutamate homeostasis by regulating astrocytic GLAST expression.
Highlights
CS-56 immunoreactivity reveals a subpopulation of astrocytes in the adult mouse cerebral cortex
We examined the distribution of Chondroitin sulfate proteoglycans (CSPGs) in the adult brain using CS-56, an anti-chondroitin sulfate antibody, and found a unique matrix structure distinct from perineuronal nets (PNNs) in the cerebral cortex
As shown in Fig. 1A2, CS-56 immunoreactivity exhibited a patchy pattern in the adult mouse cerebral cortex
Summary
CS-56 immunoreactivity reveals a subpopulation of astrocytes in the adult mouse cerebral cortex. The CS-56 antibody, which recognizes a chondroitin sulfate moiety, labeled a subset of adult brain astrocytes, yielding a patchy extracellular matrix pattern. Expression of mRNA and protein of excitatory amino acid transporter 1 (GLAST), which is a major component of astrocytic glutamate transporters, was reduced by TNR knockdown. We examined the distribution of CSPGs in the adult brain using CS-56, an anti-chondroitin sulfate antibody, and found a unique matrix structure distinct from PNNs in the cerebral cortex. We sought to identify core proteins in CS-56positive CSPGs. We first purified glycoproteins from the adult mouse cerebral cortex by anion-exchange, charge-transfer, and size-exclusion chromatographies. TNR is an extracellular matrix protein with chondroitin sulfate moieties that is expressed primarily in the central nervous system, which prompted us to examine whether it is expressed in the CS-56-positive astrocytes. Based on the present findings, the functional implications of TNR in neuro-glial interactions are discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
