Fig. 2: Dietary-induced obesity alters gene expression profiles in the hypothalamus.

a (Left) Global gene expression analysis of hypothalamic samples taken from wild-type (WT) C57BL/6J mice maintained on either a normal diet (ND) or a high-fat diet (HFD) for a period of 4 or 8 weeks. Colors represent values as log₁₀ after normalization by z-score. Low expression level is shown in green and high expression level in red. Each column represents a different mouse and in each condition there are three different mice. (Right) The most upregulated and downregulated genes affected by HFD compared with ND. b Heat map of the key genes altered by HFD and are involved in the three main signaling pathways affected by the consumption of an HFD. Colors represent values as log₁₀ after normalization by z-score. c Microarray analysis by IPA Ingenuity Pathway Analysis software of the canonical pathways affected by HFD compared with ND. Grayscale represents P-values of the statistics by the IPA Ingenuity pathway analysis. d Gene ontology (GO) enrichment pathways that were affected by the consumption of an HFD compared with ND. Grayscale represents the P-values statistics of each pathway by GO. e (Left) Western blot analysis detecting the phosphorylated status of protein kinase A (PKA) substrates of whole-hypothalamic homogenates from WT C57BL/6J mice fed either ND or HFD for 3 weeks. pPKA refers to the sum of all phosphorylated substrates of PKA. GAPDH was used as a loading control. (Right) Quantification of the total phosphorylated status of PKA substrates between whole-hypothalamic homogenates from mice fed either ND or HFD. Each line represents a different mouse. (n = 4 mice per group, ****P < 0.0001 by two-tail unpaired Student's t-test). f (left) Western blot analysis of total phosphorylated cAMP response element-binding protein (p-Creb) and cAMP response element-binding protein (CREB) protein levels in whole-hypothalamic homogenates of mice fed either ND or HFD for 3 weeks. (Right) Quantification of the total phosphorylated levels of Creb between whole-hypothalamic homogenates from mice fed either ND or HFD for 3 weeks. Each line represents a different individual mouse. (n = 3 mice per group, **P < 0.01 by two-tail unpaired Student's t-test). All data in the figure are represented as mean ± SEM