Anatomical localization of protease-activated receptor-1 and protease-mediated neuroglilal crosstalk on peri-synaptic astrocytic endfeet
Article first published online: 23 SEP 2011
© 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry
Journal of Neurochemistry
Volume 119, Issue 3, pages 460–473, November 2011
How to Cite
Shavit, E., Michaelson, D. M. and Chapman, J. (2011), Anatomical localization of protease-activated receptor-1 and protease-mediated neuroglilal crosstalk on peri-synaptic astrocytic endfeet. Journal of Neurochemistry, 119: 460–473. doi: 10.1111/j.1471-4159.2011.07436.x
- Issue published online: 12 OCT 2011
- Article first published online: 23 SEP 2011
- Accepted manuscript online: 19 AUG 2011 03:57PM EST
- Received March 15, 2011; revised manuscript received August 8, 2011; accepted August 8, 2011.
- astrocytic endfeet;
- protease-activated receptors;
J. Neurochem. (2011) 119, 460–473.
We studied the localization, activation and function of protease-activated receptor 1 (PAR-1) at the CNS synapse utilizing rat brain synaptosomes and slices. Confocal immunofluoresence and transmission electron microscopy in brain slices with pre-embedding diaminobenzidine (DAB) immunostaining found PAR-1 predominantly localized to the peri-synaptic astrocytic endfeet. Structural confocal immunofluorescence microscopy studies of isolated synaptosomes revealed spherical structures stained with anti-PAR-1 antibody which co-stained mainly for glial-filament acidic protein compared with the neuronal markers synaptophysin and PSD-95. Immunoblot studies of synaptosomes demonstrated an appropriate major band corresponding to PAR-1 and activation of the receptor by a specific agonist peptide (SFLLRN) significantly modulated phosphorylated extracellular signal-regulated kinase. A significant membrane potential depolarization was produced by thrombin (1 U/mL) and the PAR-1 agonist (100 μM) and depolarization by high K+ elevated extracellular thrombin-like activity in the synaptosomes preparation. The results indicate PAR-1 localized to the peri-synaptic astrocytic endfeet is most likely activated by synaptic proteases and induces cellular signaling and modulation of synaptic electrophysiology. A protease mediated neuron-glia pathway may be important in both physiological and pathological regulation of the synapse.