Fig. 3: Adenosine A2B receptor-mediated cAMP signalling in astrocytes regulates brain glucose metabolism.

a,c, Representative traces (a) and summary data (c) showing the effect of A2BR activation (with Bay 60-6583) followed by blockade of glucose transport with cytochalasin B (CytB; 20 µM) on changes in intracellular [glucose] (reporting the glycolytic rate), recorded using the FLIP¹²glu-700μΔ6 sensor in wild-type astrocytes and astrocytes with genetic A2BR deletion. Superimposed expanded traces show changes in astrocyte intracellular glucose concentration following application of CytB in the presence of Bay 60-6583 (inset). The slope of the sensor signal decline under conditions of glucose transport blockade was used to calculate the glycolytic rate, which was markedly reduced by A2BR deletion. b,d, Representative trace (b) and summary data (d) showing ATP-induced and adenosine-induced changes in the astrocyte cytosolic NADH–NAD⁺ redox state (reporting glucose consumption) recorded using the Peredox sensor. In panels a,b, traces show averaged (mean ± s.e.m.) recordings from several individual cells in a representative experiment. In panels c,d, the numbers in parentheses indicate the number of individual cells/number of separate cultures prepared from the same number of animals. P values were determined by one-way ANOVA followed by Sidak’s post-hoc test. e, Representative trace showing the release of lactate in response to AMPA in the absence and presence of ZM241385, recorded using microelectrode biosensors in acute brain slices. f, Representative trace and summary data showing the effects of lactate dehydrogenase inhibition with oxamate or A2BR blockade on the basal level of lactate release recorded in brain slices. The numbers in parentheses indicate the number of independent slice experiments/number of animals per experimental group. P values were determined by ANOVA followed by Dunnett’s post-hoc test. g, Adora2b^flox/flox mice were crossed with \(Aldh{1}l{{1}}^{Cre/ERT{{2}}^{+/-}}\) mice to produce animals with conditional deletion of A2BRs in brain astrocytes after tamoxifen treatment. Data are shown as individual values and mean ± s.e.m. h, A2BR deletion in astrocytes reduced the basal release of lactate recorded in brain slices. i, A2BR deletion in astrocytes depleted brain cAMP. In panels g–i, the numbers in parentheses indicate the numbers of animals per experimental group. P values were determined by two-tailed Mann–Whitney test. j, Multivariate analysis of brain metabolites by partial least squares-discriminant analysis (PLS-DA) showing a clear separation between the groups after sevenfold cross-validation for 10,000 iterations (pQ2 = 0.05). Ellipses denote 95% confidence intervals. k, Loading plot for PLS-DA in panel j showing the top five metabolites most enriched in the brains of tamoxifen-treated Adora2b^flox/flox:\(Aldh{1}l{{1}}^{Cr{e}^{-}}\) or Adora2b^flox/flox: \(Aldh{1}l{{1}}^{Cre/ERT{{2}}^{+}}\) mice (black and red symbols, respectively). l, Illustration of the pathway enrichment analysis predicting metabolic pathways or processes that are more active in the brains of control animals versus the brains of mice with conditional deletion of A2BRs in astrocytes. The most significantly affected processes are highlighted in orange.

Source Data