Transcriptomic profiling of the white adipose tissue (WAT) in ApoE3L.CETP mice fed a high fat diet (HFD) or a low fat diet (LFD) for three different time periods, or chow diet at baseline

The metabolic syndrome (MetS) is characterized by the presence of metabolic abnormalities that include abdominal obesity, dyslipidemia, hypertension, increased blood glucose/insulin resistance, hypertriglyceridemia and increased risk for cardiovascular disease (CVD). The ApoE*3Leiden.human Cholesteryl Ester Transfer Protein (ApoE3L.CETP) mouse model manifests several features of the MetS upon high fat diet (HFD) feeding. Moreover, the physiological changes in the white adipose tissue (WAT) contribute to MetS comorbidities. The aim of this study was to identify transcriptomic signatures in the gonadal WAT of ApoE3L.CETP mice in discrete stages of diet-induced MetS. For this purpose, 12 weeks old male ApoE3L.CETP mice fed for 4, 8 or 12 weeks a low fat diet (LFD) (D12450B, Research diets, New Brunswick, USA) as control groups or a high fat diet (HFD) (D14010701, Research diets, New Brunswick, USA) to induce the MetS. The clinical profile of mice was thoroughly assessed before and after diet administration and has been previously described (doi: 10.1002/jcp.28649). Mice were sacrificed at the corresponding time points and the gonadal white adipose tissues were collected to assess global gene expression changes. Baseline expression was assessed in mice 12 weeks of age that were fed with a chow diet. Total RNA from all mice (LFD or HFD group at 4, 8 and 12 weeks, 3-4 replicates/ Baseline group, 2 replicates) was labeled and hybridized to GeneChip™ Mouse Gene 2.0 ST Affymetrix expression arrays. The total of 25 arrays was analyzed to the Affymetrix Transcriptome Analysis Console (TAC) Software Version 4.0.2. To determine the differentially expressed genes, we applied the Two Way Analysis of Variance specifying two conditions (diet and time) under specific statistical criteria (p-value <0.05 and absolute fold change ≥1.5).