| 1. |
S100B is a calcium-binding protein expressed and secreted by astrocytes, which has been implicated in glial-neuronal communication.
Extracellular S100B appears to protect hippocampal neurons against toxic concentrations of glutamate. Here we investigated
a possible autocrine role of S100B in glutamate uptake activity.
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| 2. |
Astrocyte cultures were prepared of hippocampi from neonate Wistar rats. [3H] Glutamate uptake was measured after addition of S100B protein, antibody anti-S100B or TRTK-12, a peptide that blocks S100B
activity mediated by the C-terminal region.
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| 3. |
Antibody anti-S100B addition decreased glutamate uptake measured 30 min after medium replacement, without affecting cell integrity
or viability. Moreover, low levels of S100B (less than 0.1 ng/mL) stimulated glutamate uptake measured immediately after medium
replacement.
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| 4. |
This finding reinforces the importance of astrocytes in the glutamatergic transmission, particularly the role of S100B neuroprotection
against excitotoxic damage.
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Keywords astrocyte - excitotoxicity - glutamate uptake - S100B