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Liu HY, Hu P, Li Y, Sun MA, Qu H, Zong Q, Gu H, Chen X, Bao W, Cai D. Targeted inhibition of PPARα ameliorates CLA-induced hypercholesterolemia via hepatic cholesterol biosynthesis reprogramming. Liver Int 2022; 42:1449-1466. [PMID: 35184357 DOI: 10.1111/liv.15199] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Disruption of lipid metabolism is largely linked to metabolic disorders, such as hypercholesterolemia (HCL) and liver steatosis. While cholesterol metabolic re-programmers can serve as targets for relevant interventions. Here we explored the dietary conjugated linoleic acids (CLA)-induced HCL in mice and the molecular regulation behind it. METHODS A high dose of CLA supplementation in the diet was used to induce HCL in mice and was found to cause a hyper-activated cholesterol biosynthesis programme in the liver, leading to cholesterol metabolism dysregulation. The effects of a small-molecule drug targeting PPARα, i.e., GW6471 were studied in vivo in mice fed diets with CLA supplementation for 28 days, and in primary hepatocytes derived from HCL-mice in vitro. RESULTS We demonstrate that CLA induced HCL and liver steatosis through multiple pathways. Among which was the PPARα-mediated cholesterogenesis. It was found to cooperate with SREBP2 via binding to Hmgcr and Dhcr7 (genes encoding key enzymes of the cholesterol biosynthetic pathway) and recruits the histone marks H3K27ac and H3K4me1 and cofactors. PPARα inhibition disrupts its physical association with SREBP2 by blocking cobinding of PPARα and SREBP2 to the genomic DNA response element. We showed that NR RORγ functions as an essential mediator that facilitates the interaction of PPARα and SREBP2 to modulate the cholesterol biosynthesis genes expression. CONCLUSIONS Our study unravels that the small-molecule compound GW6471 exerts an attractive therapeutic effect for CLA-induced HCL, involving multiple pathways with the "PPARα-RORγ-SREBP2" being a potential complex player in this hepatic cholesterol biosynthesis programming.
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Affiliation(s)
- Hao-Yu Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Ping Hu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Yanwei Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Ming-An Sun
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Huan Qu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Qiufang Zong
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Haotian Gu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Xiaobo Chen
- Centre for Environment and Sustainability, University of Surrey, Surrey, UK
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Demin Cai
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
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Cai D, Li Y, Zhang K, Zhou B, Guo F, Holm L, Liu HY. Co-option of PPARα in the regulation of lipogenesis and fatty acid oxidation in CLA-induced hepatic steatosis. J Cell Physiol 2020; 236:4387-4402. [PMID: 33184849 DOI: 10.1002/jcp.30157] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 11/06/2022]
Abstract
Nonalcoholic-fatty-liver-disease (NAFLD) is the result of imbalances in hepatic lipid partitioning and is linked to dietary factors. We demonstrate that conjugated linoleic acid (CLA) when given to mice as a dietary supplement, induced an enlarged liver, hepatic steatosis, and increased plasma levels of fatty acid (FA), alanine transaminase, and triglycerides. The progression of NAFLD and insulin resistance was reversed by GW6471 a small-molecule antagonist of peroxisome proliferator-activated receptor α (PPARα). Transcriptional profiling of livers revealed that the genes involved in FA oxidation and lipogenesis as two core gene programs controlled by PPARα in response to CLA and GW6471 including Acaca and Acads. Bioinformatic analysis of PPARα ChIP-seq data set and ChIP-qPCR showed that GW6471 blocks PPARα binding to Acaca and Acads and abolishes the PPARα-mediated local histone modifications of H3K27ac and H3K4me1 in CLA-treated hepatocytes. Thus, our findings reveal a dual role of PPARα in the regulation of lipid homeostasis and highlight its druggable nature in NAFLD.
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Affiliation(s)
- Demin Cai
- College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Yanwei Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Kexin Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Bo Zhou
- Institute of Digestive Disease, Zhengzhou University, Zhengzhou, China
| | - Feilong Guo
- Department of General Surgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Lena Holm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Hao-Yu Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.,Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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Cong R, Qu X, Zhang H, Hu Y, Ye S, Cai D, Li X, Liu HY. Maternal high-protein diet modulates hepatic growth axis in weaning piglets by reprogramming the IGFBP-3 gene. Eur J Nutr 2019; 59:2497-2506. [PMID: 31570976 PMCID: PMC7413878 DOI: 10.1007/s00394-019-02097-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 09/19/2019] [Indexed: 10/29/2022]
Abstract
PURPOSE The aim of this study was to investigate the effects of maternal high dietary protein intake on the hepatic growth axis in offspring. METHODS Fourteen primiparous purebred Meishan sows were fed either a standard-protein (SP, n = 7) diet or a high-protein (HP, 150% of SP, n = 7) diet during pregnancy. Offspring (one male and one female per group, n = 14) on day 70 of the embryonic stage and on days 1, 35 and 180 after birth were selected, weighed and killed. Serum samples were analyzed for Tch, insulin and insulin-like growth factor-binding protein 3 (IGFBP-3) levels. Liver samples were analyzed for IGFBP-3 and IGF-I mRNA expression by qRT-PCR and for IGFBP-3, IGF1R and growth hormone receptor (GHR) protein expression by Western blotting. The underlying mechanism of IGFBP-3 regulation was determined by methylated DNA immunoprecipitation (MeDIP) and chromatin immunoprecipitation (ChIP). RESULTS High-protein exposure resulted in significantly higher body and liver weights of piglets, and it increased their serum T3 and T4 levels at birth and/or at weaning. Furthermore, the IGFBP-3 protein content in the liver and serum was significantly reduced in the HP-exposed weaning piglets, whereas at the transcriptional level IGFBP-3 mRNA expression was downregulated in the livers of HP group piglets. Finally, DNA hypermethylation and higher enrichment of the histone repressive marks H3K27me3 and H3K9me3 were observed. CONCLUSIONS Taken together, these results suggest that a maternal high-protein diet during gestation epigenetically reprograms IGFBP-3 gene expression to modulate the hepatic growth axis in weaning piglets.
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Affiliation(s)
- Rihua Cong
- College of Veterinary Medicine, Northwest A and F University, Yangling, 712100, Shannxi, China
| | - Xiaoli Qu
- School of Life Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Hui Zhang
- College of Veterinary Medicine, Northwest A and F University, Yangling, 712100, Shannxi, China
| | - Yongling Hu
- College of Veterinary Medicine, Northwest A and F University, Yangling, 712100, Shannxi, China
| | - Silin Ye
- College of Veterinary Medicine, Northwest A and F University, Yangling, 712100, Shannxi, China
| | - Demin Cai
- Department of Biochemistry and Molecular Medicine, University of California at Davis, Sacramento, 95817, CA, USA. .,College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
| | - Xian Li
- College of Veterinary Medicine, Northwest A and F University, Yangling, 712100, Shannxi, China.
| | - Hao-Yu Liu
- Department of Medical Cell Biology, Uppsala University, SE-75123, Uppsala, Sweden.
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den Hartigh LJ, Wang S, Goodspeed L, Wietecha T, Houston B, Omer M, Ogimoto K, Subramanian S, Gowda GAN, O’Brien KD, Kaiyala KJ, Morton GJ, Chait A. Metabolically distinct weight loss by 10,12 CLA and caloric restriction highlight the importance of subcutaneous white adipose tissue for glucose homeostasis in mice. PLoS One 2017; 12:e0172912. [PMID: 28245284 PMCID: PMC5330530 DOI: 10.1371/journal.pone.0172912] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/10/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Widely used as a weight loss supplement, trans-10,cis-12 conjugated linoleic acid (10,12 CLA) promotes fat loss in obese mice and humans, but has also been associated with insulin resistance. OBJECTIVE We therefore sought to directly compare weight loss by 10,12 CLA versus caloric restriction (CR, 15-25%), an acceptable healthy method of weight loss, to determine how 10,12 CLA-mediated weight loss fails to improve glucose metabolism. METHODS Obese mice with characteristics of human metabolic syndrome were either supplemented with 10,12 CLA or subjected to CR to promote weight loss. Metabolic endpoints such as energy expenditure, glucose and insulin tolerance testing, and trunk fat distribution were measured. RESULTS By design, 10,12 CLA and CR caused equivalent weight loss, with greater fat loss by 10,12 CLA accompanied by increased energy expenditure, reduced respiratory quotient, increased fat oxidation, accumulation of alternatively activated macrophages, and browning of subcutaneous white adipose tissue (WAT). Moreover, 10,12 CLA-supplemented mice better defended their body temperature against a cold challenge. However, 10,12 CLA concurrently induced the detrimental loss of subcutaneous WAT without reducing visceral WAT, promoted reduced plasma and WAT adipokine levels, worsened hepatic steatosis, and failed to improve glucose metabolism. Obese mice undergoing CR were protected from subcutaneous-specific fat loss, had improved hepatic steatosis, and subsequently showed the expected improvements in WAT adipokines, glucose metabolism and WAT inflammation. CONCLUSIONS These results suggest that 10,12 CLA mediates the preferential loss of subcutaneous fat that likely contributes to hepatic steatosis and maintained insulin resistance, despite significant weight loss and WAT browning in mice. Collectively, we have shown that weight loss due to 10,12 CLA supplementation or CR results in dramatically different metabolic phenotypes, with the latter promoting a healthier form of weight loss.
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Affiliation(s)
- Laura J. den Hartigh
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Shari Wang
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Leela Goodspeed
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Tomasz Wietecha
- Department of Medicine, Cardiology, University of Washington, Seattle, Washington, United States of America
| | - Barbara Houston
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Mohamed Omer
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Kayoko Ogimoto
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Savitha Subramanian
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - G. A. Nagana Gowda
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kevin D. O’Brien
- Department of Medicine, Cardiology, University of Washington, Seattle, Washington, United States of America
| | - Karl J. Kaiyala
- Department of Oral Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Gregory J. Morton
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
| | - Alan Chait
- Department of Medicine, Metabolism, University of Washington, Seattle, Washington, United States of America
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Epigenetic and SP1-mediated regulation is involved in the repression of galactokinase 1 gene in the liver of neonatal piglets born to betaine-supplemented sows. Eur J Nutr 2016; 56:1899-1909. [PMID: 27250629 DOI: 10.1007/s00394-016-1232-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 05/20/2016] [Indexed: 10/21/2022]
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.
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Maternal gestational betaine supplementation-mediated suppression of hepatic cyclin D2 and presenilin1 gene in newborn piglets is associated with epigenetic regulation of the STAT3-dependent pathway. J Nutr Biochem 2015; 26:1622-31. [DOI: 10.1016/j.jnutbio.2015.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 01/19/2023]
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Gestational dietary betaine supplementation suppresses hepatic expression of lipogenic genes in neonatal piglets through epigenetic and glucocorticoid receptor-dependent mechanisms. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1861:41-50. [PMID: 26494244 DOI: 10.1016/j.bbalip.2015.10.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/21/2015] [Accepted: 10/11/2015] [Indexed: 01/04/2023]
Abstract
Methyl donors play critical roles in nutritional programming through epigenetic regulation of gene expression. Here we fed gestational sows with control or betaine-supplemented diets (3g/kg) throughout the pregnancy to explore the effects of maternal methyl-donor nutrient on neonatal expression of hepatic lipogenic genes. Betaine-exposed piglets demonstrated significantly lower liver triglyceride content associated with down-regulated hepatic expression of lipogenic genes acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD) and sterol regulatory element-binding protein-1c. Moreover, s-adenosyl methionine to s-adenosyl homocysteine ratio was elevated in the liver of betaine-exposed piglets, which was accompanied by DNA hypermethylation on FAS and SCD gene promoters and more enriched repression histone mark H3K27me3 on SCD gene promoter. Furthermore, glucocorticoid receptor (GR) binding to SCD gene promoter was diminished along with reduced serum cortisol and liver GR protein content in betaine-exposed piglets. GR-mediated SCD gene regulation was confirmed in HepG2 cells in vitro. Dexamethasone (Dex) drastically increased the luciferase activity of porcine SCD promoter, while the deletion of GR response element on SCD promoter significantly attenuated Dex-mediated SCD transactivation. In addition, miR-let-7e, miR-1285 and miR-124a, which respectively target porcine SCD, ACC and GR, were significantly up-regulated in the liver of betaine-exposed piglets, being in accordance with decreased protein content of these three genes. Taken together, our results suggest that maternal dietary betaine supplementation during gestation attenuates hepatic lipogenesis in neonatal piglets via epigenetic and GR-mediated mechanisms.
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