Fig. 2: Pdk2-deficiency attenuates the diabetes-induced increase in proinflammatory cytokines, gliosis, lactate level in the hypothalamus, food intake, and blood and CSF glucose levels in mice.

GFAP (#p = 0.0101, KO + STZ for hypothalamus; ###p = 0.0003, KO + STZ for ARC; and #p = 0.0192, KO + STZ for PVN) and Iba-1 (#p = 0.0170, KO + STZ for hypothalamus, ##p = 0.0090, KO + STZ for ARC; and #p = 0.0277, KO + STZ for PVN) immunofluorescence staining and image analysis were performed using WT and Pdk2-deficient mice at 3 w post-STZ injection (a, b). Microscope data were gathered using five to six randomly selected fields captured at the same magnification. Scale bars indicate 400 µm (a, b, hypothalamus) and 200 µm (a, b, ARC and PVN). The relative expression of Tnf-α (#p = 0.0112, KO + STZ), Il-1β (###p = 0.0003, KO + STZ), and Il-6 (##p = 0.0016, KO + STZ) mRNAs in the hypothalamus after 3 w of STZ injection (c) was evaluated by real-time RT-PCR. Results for mRNA expression are displayed as the fold increase in gene expression normalized to Gapdh. Lactate concentration in hypothalamic tissues collected from WT and Pdk2 KO mice at 3 w post-STZ/vehicle injection was measured with an HPLC analyzer (d). The quantification of lactate concentration (###p = 0.0002, KO + STZ) from HPLC graphs is shown. Food intake (*p = 0.0017, KO + STZ at 22 d) (e) and fasting blood (*p = 0.0033, KO + STZ at 23 d) (f) and CSF glucose (#p = 0.0101, KO + STZ) (g) levels in mice were assessed following STZ injection at the indicated time points. Fasting blood glucose levels were measured in the pair-feeding condition following STZ administration (h). The pair-feeding condition was established based on the consumption of food by diabetic KO animals (p = 0.9997, KO + STZ for PF at 3 w). The relative expression of Npy (##p = 0.0031, KO + STZ), Agrp (###p = 0.0004, KO + STZ), and Pomc (#p = 0.0158, KO + STZ) mRNA in the hypothalamus after 3 w of STZ injection (i) was evaluated by real-time RT-PCR. mRNA expression results are displayed as the fold increase of gene expression normalized to Gapdh. *p < 0.05, **p < 0.01, or ***p < 0.001 versus the WT/KO control animals (a–d, g–i) or STZ-injected animals (e, f); #p < 0.05 or ##p < 0.01 versus indicated groups. Two-way ANOVA with Tukey’s post hoc test, n = 6 for KO + Control and 5 for other groups (a, b), n = 5 for control and 6 for STZ groups (d), n = 6 (e–h), and n = 3 (c, i); mean ± SEM. Value of “n” indicates the number of animals. Source data are provided as a Source data file. w week(s); d day(s); WT wild-type; KO knock out; STZ streptozotocin; ARC arcuate nucleus; PVN paraventricular nucleus; IR immunoreactivity; RF regular feeding; PF pair feeding; ns not significant.