Fig. 1

CS treatment increases apoE secretion and cholesterol efflux from APOE3 and APOE4 cultured glia. A In vitro study design. Mixed glial were treated with CS (0.5–500 μg/ml) or vehicle control (VC) for 6, 12, or 24h. B Cell viability of APOE4-glia in response to 6-h or 24-h treatment with increasing concentrations of CS (0.0–500 μg/ml) measured by MTT assay. There was an interaction between concentration and treatment time [F_(8,54): 20.86, p < 0.0001] because compared to vehicle, CS lowered MTT signal beyond 100 μg/ml with 24-h treatment (100: p = 0.0101; 250: p = 0.0003; 500: p < 0.0001), however, increased signal at concentrations above 25 μg/ml with 6-h treatment (25: p = 0.0029; 50: p = 0.0001; 100: p < 0.0001; 500: p < 0.0463). C Quantification of apoE secreted by APOE3- or APOE4-glia in response to 24-h CS treatment (0.0–50.0 μg/ml) when measured by ELISA (media). CS treatment increased apoE levels [treatment, F_(3,24): 29.55, p < 0.0001]. D Quantification of fold increase in secreted apoE levels (ELISA, media) by glia treated with CS (50 μg/ml) for 6, 12, and 24 h. Relative apoE levels in the media are greater with APOE4-glia at 24 h (p = 0.0002). E The effect of CS on cholesterol efflux capacity. APOE-KO, APOE3-, or APOE4-glial were treated with CS for 24 h (0.0–5.0 μg/ml), and the media was added to APOE-KO-glia loaded with BODIPY-cholesterol. CS treatment promoted cholesterol efflux [Treatment effect: F_(3,29): 9.27, p = 0.0002], with APOE3- and APOE4- but not APOE-KO-glia [Genotype effect: F_(3,29): 13.00, p < 0.0001]. Data are expressed as means ± SEM (n = 4) and were analyzed by 2-way (B, C, D) or 3-way ANOVA (1D), followed by Tukey postdoc: p < 0.05