The work described herein was performed at The Ohio State University College of Veterinary Medicine, Columbus, OH. Portions of this study were presented in abstract form at the 27th Forum of the American College of Veterinary Internal Medicine, Montreal, Quebec.
Proinflammatory Cytokine and Chemokine Gene Expression Profiles in Subcutaneous and Visceral Adipose Tissue Depots of Insulin-Resistant and Insulin-Sensitive Light Breed Horses
Article first published online: 1 JUL 2010
Copyright © 2010 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 4, pages 932–939, July/August 2010
How to Cite
Burns, T.A., Geor, R.J., Mudge, M.C., McCutcheon, L.J., Hinchcliff, K.W. and Belknap, J.K. (2010), Proinflammatory Cytokine and Chemokine Gene Expression Profiles in Subcutaneous and Visceral Adipose Tissue Depots of Insulin-Resistant and Insulin-Sensitive Light Breed Horses. Journal of Veterinary Internal Medicine, 24: 932–939. doi: 10.1111/j.1939-1676.2010.0551.x
- Issue published online: 1 JUL 2010
- Article first published online: 1 JUL 2010
- Submitted December 4, 2009; Revised March 15, 2010; Accepted April 9, 2010.
- Equine metabolic syndrome;
- Nuchal ligament;
Background: Insulin resistance has been associated with risk of laminitis in horses. Genes coding for proinflammatory cytokines and chemokines are expressed more in visceral adipose tissue than in subcutaneous adipose tissue of insulin-resistant (IR) humans and rodents.
Hypothesis/Objectives: To investigate adipose depot-specific cytokine and chemokine gene expression in horses and its relationship to insulin sensitivity (SI).
Animals: Eleven light breed mares.
Methods: Animals were classified as IR (SI = 0.58 ± 0.31 × 10−4 L/min/mU; n = 5) or insulin sensitive (IS; SI = 2.59 ± 1.21 × 10−4 L/min/mU; n = 6) based on results of a frequently sampled intravenous glucose tolerance test. Omental, retroperitoneal, and mesocolonic fat was collected by ventral midline celiotomy; incisional nuchal ligament and tail head adipose tissue biopsy specimens were collected concurrently. The expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, plasminogen activator inhibitor-1 (PAI-1), and monocyte chemoattractant protein-1 (MCP-1) in each depot was measured by real-time quantitative polymerase chain reaction. Data were analyzed by 2-way analysis of variance for repeated measures (P < .05).
Results: No differences in TNF-α, IL-1β, IL-6, PAI-1, or MCP-1 mRNA concentrations were noted between IR and IS groups for each depot. Concentrations of mRNA coding for IL-1β (P= .0005) and IL-6 (P= .004) were significantly higher in nuchal ligament adipose tissue than in other depots.
Conclusions and Clinical Importance: These data suggest that the nuchal ligament depot has unique biological behavior in the horse and is more likely to adopt an inflammatory phenotype than other depots examined. Visceral fat may not contribute to the pathogenesis of obesity-related disorders in the horse as in other species.