Effects of dietary fat and PPARδ deletion on brain lipids, fatty acid composition and lipid metabolism genes.

<p>(A) Total levels of triglyceride (TG), diglyceride (DG) and free fatty acid (FFA) extracted from total lipids from brains of f/f and KO mice fed LFD or HFD for 33 weeks (n = 6–7). Composition of individual FFA species making up the (C) FFA and (E) TG fractions were determined by GC-MS analysis, normalized to brain tissue mass (ng/mg tissue) and shown as group mean±SEM. (B) Changes in hypothalamic mRNA levels of target genes involved in (B) lipid uptake and storage (LPL, CD36, GPAT and DGAT), (D) lipid synthesis (FAS, ACC, SCD) and (F) fatty acid oxidation (ACO, PDK4, CPT1A, UCP2) were assessed by quantitative real-time PCR. Gene expression levels were normalized to endogenous RPL13A levels and are expressed as group mean±SEM relative to the level of the f/f LF diet control group. Statistical significance is designated as ^a (<i>p</i><0.05, f/f <i>vs.</i> KO, same diet) or <i>^b</i> (<i>p</i><0.05, LF <i>vs.</i> HF, same genotype), as determined by one-way ANOVA and Bonferroni post test.