Table of Contents Author Guidelines Submit a Manuscript
Journal of Lipids
Volume 2013, Article ID 890343, 16 pages
http://dx.doi.org/10.1155/2013/890343
Research Article

Trans-10, cis 12-Conjugated Linoleic Acid-Induced Milk Fat Depression Is Associated with Inhibition of PPAR Signaling and Inflammation in Murine Mammary Tissue

1Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA
2Mammalian NutriPhysioGenomics, Department of Animal Sciences, Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA

Received 24 November 2012; Accepted 18 March 2013

Academic Editor: Angel Catala

Copyright © 2013 Anil K. G. Kadegowda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Exogenous trans-10, cis-12-CLA (CLA) reduces lipid synthesis in murine adipose and mammary (MG) tissues. However, genomewide alterations in MG and liver (LIV) associated with dietary CLA during lactation remain unknown. We fed mice ( /diet) control or control + trans-10, cis-12-CLA (37 mg/day) between d 6 and d 10 postpartum. The 35,302 annotated murine exonic evidence-based oligo (MEEBO) microarray and quantitative RT-PCR were used for transcript profiling. Milk fat concentration was 44% lower on d 10 versus d 6 due to CLA. The CLA diet resulted in differential expression of 1,496 genes. Bioinformatics analyses underscored that a major effect of CLA on MG encompassed alterations in cellular signaling pathways and phospholipid species biosynthesis. Dietary CLA induced genes related to ER stress (Xbp1), apoptosis (Bcl2), and inflammation (Orm1, Saa2, and Cp). It also induced marked inhibition of PPARγ signaling, including downregulation of Pparg and Srebf1 and several lipogenic target genes (Scd, Fasn, and Gpam). In LIV, CLA induced hepatic steatosis probably through perturbations in the mitochondrial functions and induction of ER stress. Overall, results from this study underscored the role of PPARγ signaling on mammary lipogenic target regulation. The proinflammatory effect due to CLA could be related to inhibition of PPARγ signaling.