Canine Adipose Tissue Transcriptome Changes Following Four Weeks of Rapid Weight Gain

Abstract

Changes that occur in organs and tissues during the early stages of weight gain prior to the onset of clinical obesity remain unclear. The purpose of this study was to characterize adipose tissue transcriptome changes occurring after 4 wk of rapid weight gain and relate these changes to circulating metabolites. Intact female beagles were fed a commercially available high‐fat diet and randomized to either ad libitum feeding (n=5) or weight maintenance (n=4). Adipose tissue biopsies and blood samples were collected at baseline and at 4 wk. Transcriptome changes were assessed using Affymetrix Canine 2.0 microarrays and analyzed using the Limma package with an FDR = 0.05. After 4 wk, BW, body fat mass, and blood leptin and fasting glucose concentrations were elevated (P<0.05) in dogs fed ad libitum, but blood NEFA, triglyceride, insulin, adiponectin, CRP, and TNF‐α concentrations were unchanged. 139 gene transcripts were differentially expressed in adipose tissue following rapid weight gain. The majority of these changes were observed in 5 functional classes: metabolism, apoptosis/cell cycle regulation, cell adhesion, redox state, and transport. These results indicate that major changes associated with cell growth, metabolism, and redox status occur during rapid weight gain and adipose tissue expansion in the absence of systemic low‐grade inflammation. Funding: Illinois CFAR # CF071‐003‐SENGrant Funding SourceIllinois CFAR # CF071‐003‐SEN