Proceedings of The Physiological Society

Obesity (2014) Proc Physiol Soc 32, PC049

Poster Communications

Lipid profile changes in adipose tissue as a predictor of puberty and inflammation in Large White pigs

H. P. Fainberg1,4, D. Li2, F. Wessely4, K. Almond1, P. Bikker3, M. E. Symonds1, A. Mostyn4

1. School of Medicine, Division of Child Health, Obstetrics & Gynaecology, University of Nottingham, Nottingham, United Kingdom. 2. School of Biosciences, University of Nottingham, Sutton Bonington Campus, United Kingdom. 3. Wageningen UR Livestock Research, Wageningen University, Wageningen, Netherlands. 4. School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, United Kingdom.

Darwin in his book "The Descent of Man and Selection in Relation to Sex" (1871) observed that there are some characteristics that do not appear to help an organism adapt to its environment and are thus not explained by natural selection [1]. He suggested that they feature in the process of sexual selection. The induction of important traits through sexual selection and domestication such as variations in lean mass and muscular growth [2-4] are often accompanied by undesirable metabolic alterations, such as neonatal mortality and reduction of reproductive capacity [2,3]. The intensive selection pressure applied to commercial porcine breeds to increase protein accretion is accompanied by early decline in fertility and adipose tissue dysfunction [3,4]. However, the metabolic mechanisms underlying these processes in pigs are still not completely characterised. Utilizing a comprehensive lipidomics platform, we compared metabolic changes in adipose tissue of Large White pigs.Visceral (VAT) and subcutaneous adipose tissue (SCAT) were collected after humane euthanasia from 7 day (n=7, (SCAT only)) and 6 month (n=8 (both depots)) old pigs. Fatty acid (FA) profiles and gene expression of SCD-1, FASN (lipogenic genes), IL-6 and MCP-1 (pro-inflammatory genes) were assessed by gas-liquid chromatography and real-time PCR, respectively. Lipidomics data were analysed using Bayes moderated t-statistics, unsupervised hierarchical clustering and principal component analysis (PCA) using ArrayMining version 1.0 [5]. Gene expression analysis was evaluated by applying General Linear Models using SPSS 16.0.The SAT FA profile was acutely affected by the transition to puberty, resulting in twenty-two significant changes in FA content (p< 0.05), most of those increasing with age were saturated FAs including C14:0, C18:0 and C22:0. Comparative analyses of VAT and SCAT in six month old pigs identified significant changes in 13 fatty acids, with saturated fatty acids increasing only in VAT (p< 0.05). Increasing age activated the transcription of pro-inflammatory genes (IL-6 and MCP-1) but decreased the expression of lipogenic genes (FASN and SCD-1) (p< 0.05) in both depots, with more pronounced effects in VAT. Both clustering analyses indentified the visceral depot as an independent cluster at 6 months, in relation to the other two depots.In this breed, increasing age leads to a shift in lipid profile, suggesting that an enhanced presence of saturated FAs induces expression of pro-inflammatory cytokines, particularly in the visceral depot.

Where applicable, experiments conform with Society ethical requirements