Fig. 7

Astrocytes co-cultured with iGlut carrying the AD protective allele show increased energy production and ROS level and reduced glutamate uptake. A The schematic diagram depicts the FA β oxidation process of astrocytes, where they produce KB (ketone body) and ROS; the glycolysis is further facilitated by ROS and generates Lac (lactate); both KB and Lac are further transferred to surrounding neurons as the energy source. B the schematic diagram depicts the transwell co-culture system to measure KB and Lac release from mAst. C-D The amount of ketone body (β-hydroxybutyrate) and Lactate released from mAst at different time points in the transwell co-culture system. n = 6 biological replicates per group (2 clones per line and 3 biological replicates for each clone) from two independent differentiations of each line. E–F CellROX staining in iGlut-mAst co-cultures. n = 5–6 coverslips per group (2 clones per line, 2–3 coverslips for each clone with 2–5 images per coverslip, shown are example images of CD07) from two independent differentiations of each line. G Neural allelic effect on mAst glutamate uptake diagram showing the transwell coculture system for glutamate uptake assay in mAst (upper panel) and the quantification (down panel). n = 6 biological replicates per group (2 clones per line, 3 biological replicates for each clone) from two independent differentiations of each line. H The schematic diagram (upper panel) shows the test for whether ROS inhibition can affect glutamate uptake in mAst in the transwell co-culture system; quantification of glutamate uptake assay after ROS inhibition in mAst. n = 6 biological replicates per group (2 clones per line, 3 biological replicates for each clone) from two independent differentiations of each line. I CLU immunodepletion assay confirms the role of CLU in glutamate uptake by mAst. Up panel, the diagram of the CLU immunodepletion assay; bottom-left panel, the culturing and assay timeline; bottom-right panel, the quantification of residual glutamate in glutamate uptake assay. n = 7 biological replicates per group from two independent assays (the supernatant was all from one clone in CD07 line). Note the similar levels of residual glutamate of the C/C group with CLU-depletion (C/C; IgG) and the T/T group upon CLU-depletion (T/T; Anti-CLU). J A graphic model of how the AD protective allele promotes neural CLU expression, subsequently facilitating neuron-glia lipid transfer and fine-tuning mAst glutamate uptake, thereby maintaining neuronal excitability. All statistical graphs depict mean ± SEM. Scale bars are indicated in corresponding image. * p < 0.05, ** p < 0.01, *** p < 0.001, and **** p < 0.0001