Fig. 4: Downregulation of CPT1 activity by etomoxir ameliorates rotenone-induced cognitive impairment during and following a washout period and modulates gene expressions in the midbrain.

a Male C57Bl/6J and mice received vehicle (carboxymethylcellulose sodium salt, 0.5%) or rotenone (30 mg/kg) for 32 days followed by daily treatment with etomoxir or vehicle until termination at day 54. b Mean latency to fall off the rotarod test at day 54 (n = 5–10). c Mean normalized grip strength at day 54 (n = 5–10). d Visuospatial memory expressed as mean spontaneous alternation percentage in the Y-maze test at day 54 (n = 5–10). e Median time to enter dark in the dark-light box test at day 54 (n = 5–10). f Mean weight of mice at day 32 in grams (n = 5–10). g Mean serum glucose levels measured in mmol/l (n = 4–6). h Mean serum LDL-c levels measured in mmol/l (n = 4). i Mean serum HDL-c levels measured in mmol/l (n = 4). j Mean ratio of serum LDL-c/HDL-c levels (n = 4). k TH levels in the midbrain expressed as mean ng/mg total protein (n = 3). l α-Synuclein levels in the midbrain expressed as mean pg/mg total protein (n = 3). m Dopamine levels in the midbrain expressed as mean ng/mg total protein (n = 3). n Heatmap illustrating mean fold gene expression change in the midbrain of Cpt1a, Cpt1c, Nox2, Pgc1a, Iba1, Cd68 and Gfap (n = 4–5). o Cytochrome-c levels in the midbrain expressed as ng/mg total protein (n = 3). p 4-Hydroxy-2-nonenal levels in the midbrain expressed as ng/mg total protein (n = 3). q Oxidized LDL levels in the midbrain expressed as ng/mg total protein (n = 3). r Advanced glycation end product levels in the midbrain expressed as ng/mg total protein (n = 3). s IL-6 levels in the midbrain expressed as pg/mg total protein (n = 3). t IL-17A levels in the midbrain expressed as pg/mg total protein (n = 3). u TNF-α levels in the midbrain expressed as pg/mg total protein (n = 3). Serum samples and brains were obtained at day 54. Error bars represent the standard error of the mean (SEM) or interquartile rate of the median (IQR). Data are representative of one experiment. Protein levels (TH, α-synuclein, and dopamine) were normalized to total protein concentration. RT-qPCR gene expression was normalized to β-actin and Gapdh. Significant differences for behavior, serum and protein experiments; *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001. Significant differences in RT-qPCR experiments; #=significant difference between Wt+V and Wt+R+V, ¤significant difference between Wt+V and Wt+R+E, *significant difference between Wt+R+V and Wt+R+E. Wt wildtype, R rotenone, V Vehicle, E etomoxir, SAP spontaneous alternation percentage, TH tyrosine hydroxylase. Center line = mean, and whiskers = standard error of the mean except for e, center line = median and whiskers = interquartile range. Statistics: one-way ANOVA followed by Tukey post hoc test and Kruskal–Wallis test followed by Dunn post hoc test except for panels b–f, which were analyzed by two-way ANOVA followed by Tukey post hoc. We acknowledge Servier Medical Art for the mouse illustration, with the following license: https://creativecommons.org/licenses/by/3.0/. No changes were made to the drawing.