Figure 1. Effects of increasing lithium concentrations on cell viability and induction of senescence and the SASP in human iPSC-derived astrocytes. (A, B) cell viability measured by the MTT assay. Data are expressed as individual points, mean and SEM; performed in triplicate. (C, D) Relative levels of secreted IL-6 and IL-8. Conditioned media was collected 24h following induction of senescence with 1% FBS and data was normalized to cell number. (E–G) RNA isolated from human iPSCs-derived astrocytes was analyzed for IL-1α, p16INK4a and p21 mRNA levels by qPCR. Transcripts were normalized to actin and are shown as fold change over control levels. (H) GSK-3β activation measured as the proportion of phosphorylated and total GSK-3β. Data are expressed as individual points, mean and SEM. (I) SA β-gal in iPSC-derived astrocytes in the absence and presence of Aβ with increasing concentrations of lithium. Values show relative amounts of SA β-gal positive cells in three independent experiments. (J) Representative panels of SA-β gal staining under various treatment conditions.*p<0.05; **: p<0.01; ***:p < 0.001. For (C–H), data are expressed as individual points, mean and SEM of 4-5 independent experiments.