TY - JOUR
T1 - Glutamate-mediated overexpression of CD38 in astrocytes cultured with neurones
AU - Bruzzone, Santina
AU - Verderio, Claudia
AU - Schenk, Ursula
AU - Fedele, Ernesto
AU - Zocchi, Elena
AU - Matteolit, Michela
AU - De Flora, Antonio
PY - 2004/4
Y1 - 2004/4
N2 - Recently, a new system of astrocyte-neurone glutamatergic signalling has been identified. It is started in astrocytes by ectocellular, CD38-catalysed conversion of NAD+ to the calcium mobilizer cyclic ADP-ribose (cADPR). This is then pumped by CD38 itself into the cytosol where the resulting free intracellular Ca2+ concentration [Ca 2+]i transients elicit an increased release of glutamate, which can induce an enhanced Ca2+ response in neighbouring neurones. Here, we demonstrate that co-culture of either cortical or hippocampal astrocytes with neurones results in a significant overexpression of astrocyte CD38 both on the plasma membrane and intracellularly. The causal role of neurone-released glutamate in inducing overexpression of astrocyte CD38 is demonstrated by two observations: first, in the absence of neurones, induction of CD38 in pure astrocyte cultures can be obtained with glutamate and second, it can be prevented in co-cultures by glutamate receptor antagonists. The neuronal glutamate-mediated effect of neurones on astrocyte CD38 expression is paralleled by increased intracellular cADPR and [Ca2+]i levels, both findings indicating functionality of overexpressed CD38. These results reveal a new neurone-to-astrocyte glutamatergic signalling based on the CD38/cADPR system, which affects the [Ca2+]i in both cell types, adding further complexity to the bi-directional patterns of communication between astrocytes and neurones.
AB - Recently, a new system of astrocyte-neurone glutamatergic signalling has been identified. It is started in astrocytes by ectocellular, CD38-catalysed conversion of NAD+ to the calcium mobilizer cyclic ADP-ribose (cADPR). This is then pumped by CD38 itself into the cytosol where the resulting free intracellular Ca2+ concentration [Ca 2+]i transients elicit an increased release of glutamate, which can induce an enhanced Ca2+ response in neighbouring neurones. Here, we demonstrate that co-culture of either cortical or hippocampal astrocytes with neurones results in a significant overexpression of astrocyte CD38 both on the plasma membrane and intracellularly. The causal role of neurone-released glutamate in inducing overexpression of astrocyte CD38 is demonstrated by two observations: first, in the absence of neurones, induction of CD38 in pure astrocyte cultures can be obtained with glutamate and second, it can be prevented in co-cultures by glutamate receptor antagonists. The neuronal glutamate-mediated effect of neurones on astrocyte CD38 expression is paralleled by increased intracellular cADPR and [Ca2+]i levels, both findings indicating functionality of overexpressed CD38. These results reveal a new neurone-to-astrocyte glutamatergic signalling based on the CD38/cADPR system, which affects the [Ca2+]i in both cell types, adding further complexity to the bi-directional patterns of communication between astrocytes and neurones.
KW - Astrocytes
KW - CD38
KW - Cyclic ADP-ribose
KW - Glutamate
KW - Intracellular calcium
KW - Neurones
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M3 - Article
C2 - 15030411
AN - SCOPUS:1842509947
VL - 89
SP - 264
EP - 272
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 1
ER -