Demin Cai1, Mengjie Yuan1, Haoyu Liu2, Zhengqiang Han1, Shifeng Pan1,3, Yang Yang1, Ruqian Zhao4,5. 1. Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. 2. Department of Medical Cell Biology, University of Uppsala, 75123, Uppsala, Sweden. 3. College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China. 4. Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. zhao.ruqian@gmail.com. 5. Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing, 210095, People's Republic of China. zhao.ruqian@gmail.com.
Abstract
PURPOSE: In this study, we sought to investigate the effects of maternal betaine supplementation on the expression and regulation of GALK1 gene in the liver of neonatal piglets. METHODS: Sixteen sows of two groups were fed control or betaine-supplemented diets (3 g/kg), respectively, throughout the pregnancy. Newborn piglets were individually weighed immediately after birth, and one male piglet close to mean body weight from the same litter was selected and killed before suckling. Serum samples of newborn piglets were analyzed for biochemical indexes, hormone and amino acid levels. Liver samples were analyzed for GALK1 expression by real-time PCR and western blotting, while GALK1 regulational mechanism was analyzed by methylated DNA immunoprecipitation, chromatin immunoprecipitation and microRNAs expression. RESULTS: Betaine-exposed neonatal piglets had lower serum concentration of galactose, which was associated with significantly down-regulated hepatic GALK1 expression. The repression of GALK1 mRNA expression was associated with DNA hypermethylation and more enriched repression histone mark H3K27me3 on its promoter. Binding sites of SP1, GR and STAT3 were predicted on GALK1 promoter, and decreased SP1 protein content and lower SP1 binding to GALK1 promoter were detected in the liver of betaine-exposed piglets. Furthermore, the expression of miRNA-149 targeting GALK1 was up-regulated in the liver of betaine-exposed piglets, along with elevated miRNAs-processing enzymes Dicer and Ago2. CONCLUSIONS: Our results suggest that maternal dietary betaine supplementation during gestation suppresses GALK1 expression in the liver of neonatal piglets, which involves complex gene regulation mechanisms including DNA methylation, histone modification, miRNAs expression and SP1-mediated transcriptional modulation.
PURPOSE: In this study, we sought to investigate the effects of maternal betaine supplementation on the expression and regulation of GALK1 gene in the liver of neonatal piglets. METHODS: Sixteen sows of two groups were fed control or betaine-supplemented diets (3 g/kg), respectively, throughout the pregnancy. Newborn piglets were individually weighed immediately after birth, and one male piglet close to mean body weight from the same litter was selected and killed before suckling. Serum samples of newborn piglets were analyzed for biochemical indexes, hormone and amino acid levels. Liver samples were analyzed for GALK1 expression by real-time PCR and western blotting, while GALK1 regulational mechanism was analyzed by methylated DNA immunoprecipitation, chromatin immunoprecipitation and microRNAs expression. RESULTS:Betaine-exposed neonatal piglets had lower serum concentration of galactose, which was associated with significantly down-regulated hepatic GALK1 expression. The repression of GALK1 mRNA expression was associated with DNA hypermethylation and more enriched repression histone mark H3K27me3 on its promoter. Binding sites of SP1, GR and STAT3 were predicted on GALK1 promoter, and decreased SP1 protein content and lower SP1 binding to GALK1 promoter were detected in the liver of betaine-exposed piglets. Furthermore, the expression of miRNA-149 targeting GALK1 was up-regulated in the liver of betaine-exposed piglets, along with elevated miRNAs-processing enzymes Dicer and Ago2. CONCLUSIONS: Our results suggest that maternal dietary betaine supplementation during gestation suppresses GALK1 expression in the liver of neonatal piglets, which involves complex gene regulation mechanisms including DNA methylation, histone modification, miRNAs expression and SP1-mediated transcriptional modulation.
Authors: Peter Jepsen; Hendrik Vilstrup; Peter Ott; Susanne Keiding; Per K Andersen; Niels Tygstrup Journal: BMC Gastroenterol Date: 2009-06-30 Impact factor: 3.067
Authors: Colin Delaney; Sanjay K Garg; Chris Fernandes; Mark Hoeltzel; Robert H Allen; Sally Stabler; Raymond Yung Journal: PLoS One Date: 2013-02-21 Impact factor: 3.240