[Frontiers in Bioscience E4, 2605-2616, June 1, 2012]

Identifying lipid metabolism genes in pig liver after clenbuterol administration

Qiuyue Liu1, Jin Zhang2, Wei Guo1, Yiqiang Zhao1, Xiaoxiang Hu1, Ning Li1

1State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China, 2College of Life Science and Biotechnology, Hebei Normal University of Science& Technology, Qinhuangdao, 066600, China

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
3.1. Animal management and tissue collection
3.2. Histology
3.3. RNA isolation and Microarray hybridization
3.4. Data analysis
3.4.1.Validation by quantitative real-time RT-PCR
3.5. Clustering of differentially expressed genes
3.6. Gene function and pathway enrichment analysis
3.7. Prioritization of differentially expressed genes
4. Results
4.1. Phenotypic changes
4.2. Differentially expressed transcripts in liver tissue
4.3. Hierarchical Clustering of differentially expressed probe sets
4.4. qPCR validation of differentially expressed transcripts/genes
4.5. Functional enrichment of differentially expressed transcripts/genes
4.6. Pathways enrichment of differentially expressed transcripts/genes
4.7. Prioritization of differentially expressed transcripts/genes
5.Discussion
5.1. Phenotype comparison
5.2. Function and pathway enrichments of differentially expressed genes
5.2.1. Glycogen and fatty acid metabolism
5.2.2. Cell development, differentiation, and intracellular signaling regulation
5.2.3. Cell adhesion molecules
5.3. Prioritized list of differentially expressed genes related to Clenbuterol's repartitioning effect
5.4. Comparison of the cDNA microarray data of adipose tissue derived from identically managed animals
6. Conclusions
7. Acknowledgement
8. References

1. ABSTRACT

Clenbuterol is a repartition agent (beta 2-adrenoceptor agonist) that can decrease fat deposition and increase skeletal muscle growth at manageable dose. To better understand the molecular mechanism of Clenbuterol's action, GeneChips and real-time PCR were used to compare the gene expression profiles of liver tissue in pigs with/without administration of Clenbuterol. Metabolism effects and the global gene expression profiles of liver tissue from Clenbuterol-treated and untreated pigs were conducted. Function enrichment tests showed that the differentially expressed genes are enriched in glycoprotein protein, plasma membrane, fatty acid and amino acid metabolic process, and cell differentiation and signal transduction groups. Pathway mining analysis revealed that physiological pathways such as MAPK, cell adhesion molecules, and the insulin signaling pathway, were remarkably regulated when Clenbuterol was administered. Gene prioritization algorithm was used to associate a number of important differentially expressed genes with lipid metabolism in response to Clenbuterol. Genes identified as differentially expressed in this study will be candidates for further investigation of the molecular mechanisms involved in Clenbuterol's effects on adipose and skeletal muscle tissue.