Submitted to: Animal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/1/2011
Publication Date: 7/1/2011
Citation: Hausman, G.J., Barb, C.R., Dean, R.G. 2011. Gene expression profiling in developing pig adipose tissue: non-secreted regulatory proteins. Animal. 5(07):1071-1081. Interpretive Summary: Rodent and human studies show that fat tissue expresses a number of genes that ultimately play key regulatory roles during development. Identification of new fat tissue regulatory factors and factors associated with leptin expression continues on as global approaches are used to study fat tissue proteins and genes. The gene expression levels in pig fat tissue of a number of regulatory factors associated with leptin were studied in growing pigs. Most gene levels examined did not change with age. However, the gene levels of several regulatory factors changed with age and a number of genes were identified in pig fat tissue for the first time. Therefore, fat tissue regulatory factors represent a potential new target for regulating physiological processes in the growing animal.
Technical Abstract: The expression of many genes encoding secreted and non-secreted factors have been studied in human and rodent adipose tissue with cDNA microarrays, but few such studies in adipose tissue from growing pigs have been reported. Total RNA was collected at slaughter from outer subcutaneous adipose tissue (OSQ) and middle subcutaneous adipose tissue (MSQ) samples from gilts at 90, 150, and 210 d ( n = 5 / age). Dye-labeled cDNA probes were hybridized to custom microarrays (70 mer oligonucleotides) representing about 600 pig genes involved in growth and reproduction. Gene expression intensity ratios changed little with age for 100 transcription factors, nuclear receptors, enzymes and other regulatory proteins in OSQ and MSQ from pigs between 90 - 210 d of age. However, the relative expression of 13 genes distinguished OSQ and MSQ depots in growing pigs. The expression of several genes were influenced by age including an increase in CCND3, HSF1 and PTGR1 expression in MSQ and a decrease in UCP2 and prohibitin -2 expression in OSQ. These studies demonstrate for the first time the expression of several key regulatory genes in pig adipose tissue. Simple linear regression analysis showed that leptin gene expression was associated with expression of some of these regulatory genes. Negative associations between expression of some regulatory factors and leptin gene expression indicated that local leptin may decrease or antagonize adipogenesis.