Figure 6.

Simultaneous stimulation of AMPARs and mGluRs elicits a TACE-dependent increase in TGFα release from hypothalamic astrocytes. A, Accumulation of TGFα in the culture medium increases after exposing hypothalamic astrocytes to the glutamate receptor agonists AMPA plus tACPD (100 μm each), and this increase is prevented by blockade of TACE activity with TAPI-2. B, The cellular content of TGFα decreases in AMPA plus tACPD-treated astrocytes, concomitantly with the enhanced release of the mature peptide into the culture medium, and the decrease is prevented by blocking TACE activity with TAPI-2. All measurements were made after a 4 h incubation period with the receptor agonists. TGFα was measured with an ELISA that uses antibodies directed against the TGFα mature peptide and that is able to detect both the cleaved peptide and the peptide still attached to its precursor. *p < 0.05 versus all other groups (n = 8–12 independent observations per group).