Genes are differentially expressed in the epididymal fat of rats rendered obese by a high-fat diet

The aim of present study was to identify the visceral adipose tissue genes differentially expressed in a well-characterized rat model of high-fat diet (HFD)-induced obesity. Male Sprague-Dawley rats were fed either the HFD (17 g lard + 3 g corn oil/100 g) or the normal diet (5 g corn oil/100 g) for 9 weeks. The HFD rats weighed 55% more and accumulated 85% to 133% greater visceral fats than did the normal-diet rats (P < .05). Animals given the HFD for 9 weeks acquired dyslipidemia, fatty liver, insulin resistance, and hyperleptinemia along with the overexpression of several obesity-related genes, such as leptin, tumor necrosis factor alpha, resistin, peroxisome proliferator-activated receptor gamma2, CCAAT/enhancer-binding protein alpha, and sterol regulatory element-binding protein-1c, in the epididymal adipose tissue. The differential gene expression profile obtained from the cDNA microarray analysis followed by the real-time polymerase chain reaction confirmation led to a recruitment of several uncharacterized adipose tissue genes responding to the HFD. We report herein, for the first time, that a series of genes which might be implicated in the insulin-stimulated glucose transporter 4 translocation, such as protein phosphatase 2 (formerly 2A), cell division cycle 42-interacting protein 4, syntaxin 6, linker of T-cell receptor pathways 10, as well as the genes which might be involved in cancer development, such as heat shock 10-kd protein 1, and ras-related C3 botulinum toxin substrate 1, were differentially expressed in the epididymal adipose tissue of rats rendered obese by an HFD.