Obese canine skeletal muscle transcriptome exhibits altered inflammatory signaling

Abstract

Obesity induces changes in skeletal muscle that lead to insulin resistance and metabolic dysfunction. The purpose of this study was to characterize the skeletal muscle transcriptome of lean and obese dogs after 24 wk of diet‐induced obesity. 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). Latissimus dorsi muscle and blood samples were collected and body composition was measured at baseline and at 24 wk. The skeletal muscle transcriptome of lean and obese dogs, at 24 wk, were assessed using Affymetrix Canine 2.0 microarrays and analyzed using the Limma package. Obese dogs had increased (P≤0.05) BW, body fat mass, bone mineral mass, and blood leptin and insulin concentrations, but lean mass and blood NEFA, triglycerides, glucose, and adiponectin concentrations were unchanged. 77 gene transcripts were differentially expressed in obese dogs. Functional classification of 55 annotated gene transcripts revealed differential regulation of cell signaling, transport, growth, and transcription. The obese state had decreased expression of anti‐inflammatory gene transcripts (SOCS2, CISH) and increased expression of pro‐inflammatory gene transcripts (STAT2, FLT1, TPST1). These results indicate that skeletal muscle of obese dogs has increased inflammation.Funding: Illinois CFAR # CF071‐003‐SEN