1. Ca 2+ ‐dependent release of <scp>ATP</scp> from astrocytes affects herpes simplex virus type 1 infection of neurons
- Author
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Claudio Grassi, Domenica Donatella Li Puma, Giacomo Lazzarino, Giovanna De Chiara, Anna Teresa Palamara, Barbara Tavazzi, Maria Elena Marcocci, and Roberto Piacentini
- Subjects
0301 basic medicine ,Cell type ,Settore BIO/09 - FISIOLOGIA ,GSK-3 beta ,Biology ,medicine.disease_cause ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,GSK-3 ,Extracellular ,medicine ,Receptor ,GSK-3β ,Purinergic receptor ,astrocytes ,herpes simplex virus ,Cell biology ,ATP ,030104 developmental biology ,Herpes simplex virus ,medicine.anatomical_structure ,Neurology ,P2Rs ,030217 neurology & neurosurgery ,Intracellular ,Astrocyte - Abstract
Astrocytes provide metabolic support for neurons and modulate their functions by releasing a plethora of neuroactive molecules diffusing to neighboring cells. Here we report that astrocytes also play a role in cortical neurons' vulnerability to Herpes simplex virus type-1 (HSV-1) infection through the release of extracellular ATP. We found that the interaction of HSV-1 with heparan sulfate proteoglycans expressed on the plasma membrane of astrocytes triggered phospholipase C-mediated IP3-dependent intracellular Ca(2+)transients causing extracellular release of ATP. ATP binds membrane purinergic P2 receptors (P2Rs) of both neurons and astrocytes causing an increase in intracellular Ca(2+)concentration that activates the Glycogen Synthase Kinase (GSK)-3 beta, whose action is necessary for HSV-1 entry/replication in these cells. Indeed, in co-cultures of neurons and astrocytes HSV-1-infected neurons were only found in proximity of infected astrocytes releasing ATP, whereas in the presence of fluorocitrate, an inhibitor of astrocyte metabolism, switching-off the HSV-1-induced ATP release, very few neurons were infected. The addition of exogenous ATP, mimicking that released by astrocytes after HSV-1 challenge, restored the ability of HSV-1 to infect neurons co-cultured with metabolically-inhibited astrocytes. The ATP-activated, P2R-mediated, and GSK-3-dependent molecular pathway underlying HSV-1 infection is likely shared by neurons and astrocytes, given that the blockade of either P2Rs or GSK-3 activation inhibited infection of both cell types. These results add a new layer of information to our understanding of the critical role played by astrocytes in regulating neuronal functions and their response to noxious stimuli including microbial agents via Ca2+-dependent release of neuroactive molecules.
- Published
- 2020