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Nitric oxide induces the expression of the monocarboxylate transporter MCT4 in cultured astrocytes by a cGMP‐independent transcriptional activation
Author(s) -
Marcillac Fabrice,
Brix Britta,
Repond Cendrine,
Jöhren Olaf,
Pellerin Luc
Publication year - 2011
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.21240
Subject(s) - monocarboxylate transporter , biology , nitric oxide , transporter , astrocyte , microbiology and biotechnology , glycolysis , intracellular , neuroglia , central nervous system , downregulation and upregulation , cell culture , gene expression , biochemistry , metabolism , gene , endocrinology , genetics
The monocarboxylate transporter MCT4 is a proton‐linked carrier particularly important for lactate release from highly glycolytic cells. In the central nervous system, MCT4 is exclusively expressed by astrocytes. Surprisingly, MCT4 expression in primary cultures of mouse cortical astrocytes is conspicuously low, suggesting that an external, nonastrocytic signal is necessary to obtain the observed pattern of expression in vivo . Here, we demonstrate that nitric oxide (NO), delivered by various NO donors, time‐ and dose‐dependently induces MCT4 expression in cultured cortical astrocytes both at the mRNA and protein levels. In contrast, NO does not enhance the expression of MCT1, the other astrocytic monocarboxylate transporter. The transcriptional effect of NO is not mediated by a cGMP‐dependent mechanism as shown by the absence of effect of a cGMP analog or of a selective guanylate cyclase inhibitor. NO causes an increase in astrocytic lactate transport capacity which requires the enhancement of MCT4 expression as both are prevented by the use of a specific siRNA against MCT4. In addition, cumulated lactate release by astrocytes over a period of 24 h was also enhanced by NO treatment. Our data suggest that NO represents a putative intercellular signal to control MCT4 expression in astrocytes and in doing so, to facilitate lactate transfer to other surrounding cell types in the central nervous system. © 2011 Wiley‐Liss, Inc.