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Petricek KM, Kirchner M, Sommerfeld M, Stephanowitz H, Kiefer MF, Meng Y, Dittrich S, Dähnhardt HE, Mai K, Krause E, Mertins P, Wowro SJ, Schupp M. An acetylated Lysine Residue of Its Low-glucose Inhibitory Domain Controls Activity and Protein Interactions of ChREBP. J Mol Biol 2025; 437:169189. [PMID: 40339981 DOI: 10.1016/j.jmb.2025.169189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2025] [Revised: 04/17/2025] [Accepted: 05/01/2025] [Indexed: 05/10/2025]
Abstract
Carbohydrate response element-binding protein (ChREBP) is a transcription factor activated by glucose metabolites that orchestrates the expression of genes involved in glycolysis, de novo lipogenesis, and ATP homeostasis. Inadequate ChREBP activity impairs the cellular adaptations to glucose exposure and in humans associates with dyslipidemia, fatty liver disease, and type 2 diabetes. ChREBP activity is regulated by cytosolic-nuclear translocation involving its low-glucose inhibitory domain (LID). Whether this domain is targeted by post-translational lysine acetylation is unknown. Here we report a novel LID acetylation site that controls activity and protein interactions of ChREBP. Mutation of this residue increased glucose-induced activity and target gene expression of ChREBP. Mechanistically, mutant ChREBP protein showed more nuclear localization and enhanced genomic binding to a target promoter. Interactions with proteins that exhibit differential binding upon glucose exposure were attenuated by the mutation, demonstrating the importance of the LID in the formation of the protein interactome. Particularly interactions with 14-3-3 proteins, factors that regulate cytosolic/nuclear trafficking of ChREBP, were reduced, whereas interactions with proteins of the nucleosome remodeling deacetylase complex (NuRD) were increased. These molecular insights may shape new therapeutic strategies to target ChREBP activity and counteract metabolic diseases.
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Affiliation(s)
- Konstantin M Petricek
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany; Department of Endocrinology and Metabolism, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, European Reference Network on Rare Endocrine Diseases (ENDO-ERN), Berlin, Germany
| | - Marieluise Kirchner
- Core Unit Proteomics, Berlin Institute of Health at Charité - Universitätsmedizin Berlin and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Manuela Sommerfeld
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Heike Stephanowitz
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Marie F Kiefer
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Yueming Meng
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sarah Dittrich
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Henriette E Dähnhardt
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Knut Mai
- Department of Endocrinology and Metabolism, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, European Reference Network on Rare Endocrine Diseases (ENDO-ERN), Berlin, Germany; German Center for Diabetes Research (DZD e.V.), Neuherberg, Germany; Department of Human Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | - Eberhard Krause
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | - Philipp Mertins
- Core Unit Proteomics, Berlin Institute of Health at Charité - Universitätsmedizin Berlin and Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Sylvia J Wowro
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Michael Schupp
- Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular Metabolic Renal Research, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
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Wang CM, Bai QF, Liu YJ, Lin J, Wei CC, Ma XH, Zhao JM, Zhu M, Chen YX, Shi YN, Shi JH, Zhang WJ. ChREBP mediates metabolic remodeling in FBP1-deficient liver. Am J Physiol Cell Physiol 2025; 328:C1234-C1246. [PMID: 40055186 DOI: 10.1152/ajpcell.00875.2024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2024] [Revised: 11/30/2024] [Accepted: 03/03/2025] [Indexed: 04/01/2025]
Abstract
The deficiency of fructose-1,6-bisphosphatase 1 (FBP1), a key enzyme of gluconeogenesis, causes fatty liver. However, its underlying mechanism and physiological significance are not fully understood. Here we demonstrate that carbohydrate response element-binding protein (ChREBP) mediates lipid metabolic remodeling and promotes progressive triglyceride accumulation against metabolic injury in adult FBP1-deficient liver. Inducible liver-specific deletion of Fbp1 gene caused progressive hepatomegaly and hepatic steatosis, with a marked increase in hepatic de novo lipogenesis (DNL) as well as a decrease in plasma β-hydroxybutyrate levels. Notably, FBP1 deficiency resulted in a persistent activation of ChREBP and its target genes involved in glycolysis, lipogenesis, and fatty acid oxidation, even under fasting conditions. Furthermore, liver-specific ChREBP disruption could markedly restore the phenotypes of enhanced DNL and triglyceride accumulation in FBP1-deficient liver but exacerbated its hepatomegaly and liver injury, which was associated with remarkable energy deficit, impaired mammalian target of rapamycin (mTOR) activation, and increased oxidative stress. Furthermore, metabolomics analysis revealed a robust elevation of phosphoenolpyruvate, phosphoglycerates, phospholipids, and ceramides caused by ChREBP deletion in FBP1-deficient liver. Put together, these results suggest that overactivation of ChREBP pathway mediates liver metabolic remodeling in the absence of FBP1, which contributes to the pathogenesis of progressive hepatic steatosis and provides a protection against liver injury. Thus, our findings point to a beneficial role of ChREBP in metabolic remodeling in the context of excessive gluconeogenic intermediates.NEW & NOTEWORTHY FBP1 deficiency in adulthood causes progressive hepatic steatosis due to the overactivation of ChREBP pathway, which enhances lipid synthesis and inhibits fat oxidation. ChREBP-mediated metabolic remodeling protects against liver injury caused by energy deficit and oxidative stress in FBP1-deficient liver.
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Affiliation(s)
- Chen-Ma Wang
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
| | - Qiu-Fang Bai
- Department of Endocrinology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China
| | - Ya-Jin Liu
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
| | - Jie Lin
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
| | - Chun-Chun Wei
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
| | - Xian-Hua Ma
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
| | - Jia-Mu Zhao
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
| | - Meng Zhu
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
| | - Yu-Xia Chen
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
| | - Ya-Nan Shi
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
| | - Jian-Hui Shi
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
| | - Weiping J Zhang
- NHC Key Lab of Hormones and Development and Tianjin Key Lab of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Institute of Endocrinology, Tianjin, People's Republic of China
- National Key Laboratory of Immunity and Inflammation, Department of Pathophysiology, Naval Medical University, Shanghai, People's Republic of China
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An J, Astapova I, Zhang G, Cangelosi AL, Ilkayeva O, Marchuk H, Muehlbauer MJ, George T, Brozinick J, Herman MA, Newgard CB. Integration of metabolomic and transcriptomic analyses reveals regulatory functions of the ChREBP transcription factor in energy metabolism. Cell Rep 2025; 44:115278. [PMID: 39921857 DOI: 10.1016/j.celrep.2025.115278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2024] [Revised: 12/03/2024] [Accepted: 01/16/2025] [Indexed: 02/10/2025] Open
Abstract
The transcription factor carbohydrate response element binding protein (ChREBP) activates genes of glucose, fructose, and lipid metabolism in response to carbohydrate feeding. Integrated transcriptomic and metabolomic analyses in rats with GalNac-siRNA-mediated suppression of ChREBP expression in liver reveal other ChREBP functions. GalNac-siChREBP treatment reduces expression of genes involved in coenzyme A (CoA) biosynthesis, with lowering of CoA and short-chain acyl-CoA levels. Despite suppression of pyruvate kinase, pyruvate levels are maintained, possibly via increased expression of pyruvate and amino acid transporters. In addition, expression of multiple anaplerotic enzymes is decreased by GalNac-siChREBP treatment, affecting TCA cycle intermediates. Finally, GalNAc-siChREBP treatment suppresses late steps in purine and NAD synthesis, with increases in precursors and lowering of end products in both pathways. In sum, our study reveals functions of ChREBP beyond its canonical roles in carbohydrate and lipid metabolism to include regulation of substrate transport, mitochondrial function, and energy balance.
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Affiliation(s)
- Jie An
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - Inna Astapova
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Guofang Zhang
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA; Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Andrew L Cangelosi
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA; Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Hannah Marchuk
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - Michael J Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | - Tabitha George
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
| | | | - Mark A Herman
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Christopher B Newgard
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA; Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center, Durham, NC, USA; Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC, USA.
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Eccles-Miller JA, Johnson TD, Baldwin WS. Sexually Dimorphic Effects of CYP2B6 in the Development of Fasting-Mediated Steatosis in Mice: Role of the Oxylipin Products 9-HODE and 9-HOTrE. Biomedicines 2025; 13:295. [PMID: 40002708 PMCID: PMC11853041 DOI: 10.3390/biomedicines13020295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2024] [Revised: 01/17/2025] [Accepted: 01/19/2025] [Indexed: 02/27/2025] Open
Abstract
Background: Cytochrome P450 2B6 (CYP2B6) is a sexually dimorphic, anti-obesity CYP enzyme responsible for the metabolism of xeno- and endobiotics, including the metabolism of polyunsaturated fatty acids (PUFAs) into 9-hydroxyoctadecadienoic acid (9-HODE) and 9-hydroxyoctadecatrienoic acid (9-HOTrE). However, humanized CYP2B6 transgenic (hCYP2B6-Tg) mice are sensitive to diet-induced hepatic steatosis despite their resistance to obesity. The purpose of this study was to determine if 9-HODE, 9-HOTrE, or other factors contribute to the sexually dimorphic steatosis observed in hCYP2B6-Tg mice. Results: Cyp2b9/10/13-null (Cyp2b-null) mice were injected with either 9-HODE or 9-HOTrE for 2 days and were then subjected to a fasting period of 20 h to induce steatosis. Serum lipids were moderately increased, especially in females, after 9-HODE (triglycerides (TGs), very low-density lipoproteins (VLDLs)) and 9-HOTrE (high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), cholesterol) treatment. No change in hepatic lipids and few changes in hepatic gene expression were observed in mice treated with either oxylipin, suggesting that these oxylipins had minimal to moderate effects. Therefore, to further investigate CYP2B6's role in steatosis, hCYP2B6-Tg and Cyp2b-null mice were subjected to a 20 h fast and compared. Both male and female hCYP2B6-Tg mice exhibited increased steatosis compared to Cyp2b-null mice. Serum cholesterol, triglycerides, HDLs, and VLDLs were increased in hCYP2B6-Tg males. Serum triglycerides and VLDLs were decreased in hCYP2B6-Tg females, suggesting the greater hepatic retention of lipids in females. Hepatic oxylipin profiles revealed eight perturbed oxylipins in female hCYP2B6-Tg mice and only one in males when compared to Cyp2b-null mice. RNA-seq also demonstrated greater effects in females in terms of the number of genes and gene ontology (GO) terms perturbed. There were only a few overlapping GO terms between sexes, and lipid metabolic processes were enriched in hCYP2B6-Tg male mice but were repressed in hCYP2B6-Tg females compared to Cyp2b-nulls. Conclusions: hCYP2B6-Tg mice are sensitive to fasting-mediated steatosis in males and females, although the responses are different. In addition, the oxylipins 9-HODE and 9-HOTrE are unlikely to be the primary cause of CYP2B6's pro-steatotic effects.
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Affiliation(s)
| | | | - William S. Baldwin
- Biological Sciences, Clemson University, Clemson, SC 29634, USA; (J.A.E.-M.); (T.D.J.)
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An J, Astapova I, Zhang G, Cangelosi AL, Ilkayeva O, Marchuk H, Muehlbauer MJ, George T, Brozinick J, Herman MA, Newgard CB. Integration of metabolomic and transcriptomic analyses reveals novel regulatory functions of the ChREBP transcription factor in energy metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.17.613577. [PMID: 39345566 PMCID: PMC11429843 DOI: 10.1101/2024.09.17.613577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Carbohydrate Response Element-Binding Protein (ChREBP) is a transcription factor that activates key genes involved in glucose, fructose, and lipid metabolism in response to carbohydrate feeding, but its other potential roles in metabolic homeostasis have not been as well studied. We used liver-selective GalNAc-siRNA technology to suppress expression of ChREBP in rats fed a high fat/high sucrose diet and characterized hepatic and systemic responses by integrating transcriptomic and metabolomic analyses. GalNAc-siChREBP-treated rats had lower levels of multiple short-chain acyl CoA metabolites compared to rats treated with GalNAc-siCtrl containing a non-targeting siRNA sequence. These changes were related to a sharp decrease in free CoA levels in GalNAc-siChREBP treated-rats, accompanied by lower expression of transcripts encoding enzymes and transporters involved in CoA biosynthesis. These activities of ChREBP likely contribute to its complex effects on hepatic lipid and energy metabolism. While core enzymes of fatty acid (FA) oxidation are induced by ChREBP knockdown, accumulation of liver acylcarnitines and circulating ketones indicate diversion of acetyl CoA to ketone production rather than complete oxidation in the TCA cycle. Despite strong suppression of pyruvate kinase and activation of pyruvate dehydrogenase, pyruvate levels were maintained, likely via increased expression of pyruvate transporters, and decreased expression of lactate dehydrogenase and alanine transaminase. GalNAc-siChREBP treatment increased hepatic citrate and isocitrate levels while decreasing levels of distal TCA cycle intermediates. The drop in free CoA levels, needed for the 2-ketoglutarate dehydrogenase reaction, as well as a decrease in transcripts encoding the anaplerotic enzymes pyruvate carboxylase, glutamate dehydrogenase, and aspartate transaminase likely contributed to these effects. GalNAc-siChREBP treatment caused striking increases in PRPP and ZMP/AICAR levels, and decreases in GMP, IMP, AMP, NaNM, NAD(P), and NAD(P)H levels, accompanied by reduced expression of enzymes that catalyze late steps in purine and NAD synthesis. ChREBP suppression also increased expression of a set of plasma membrane amino acid transporters, possibly as an attempt to replenish TCA cycle intermediates. In sum, combining transcriptomic and metabolomic analyses has revealed regulatory functions of ChREBP that go well beyond its canonical roles in control of carbohydrate and lipid metabolism to now include mitochondrial metabolism and cellular energy balance.
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Affiliation(s)
- Jie An
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
| | - Inna Astapova
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Baylor College of Medicine
| | - Guofang Zhang
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center
| | - Andrew L. Cangelosi
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
| | - Olga Ilkayeva
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center
| | - Hannah Marchuk
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
| | - Michael J. Muehlbauer
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
| | - Tabitha George
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
| | | | - Mark A. Herman
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Baylor College of Medicine
| | - Christopher B. Newgard
- Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center
- Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Duke University Medical Center
- Department of Pharmacology & Cancer Biology, Duke University Medical Center
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McNeill SM, Zhao P. The roles of RGS proteins in cardiometabolic disease. Br J Pharmacol 2024; 181:2319-2337. [PMID: 36964984 DOI: 10.1111/bph.16076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/12/2023] [Accepted: 03/20/2023] [Indexed: 03/27/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are the most prominent receptors on the surface of the cell and play a central role in the regulation of cardiac and metabolic functions. GPCRs transmit extracellular stimuli to the interior of the cells by activating one or more heterotrimeric G proteins. The duration and intensity of G protein-mediated signalling are tightly controlled by a large array of intracellular mediators, including the regulator of G protein signalling (RGS) proteins. RGS proteins selectively promote the GTPase activity of a subset of Gα subunits, thus serving as negative regulators in a pathway-dependent manner. In the current review, we summarise the involvement of RGS proteins in cardiometabolic function with a focus on their tissue distribution, mechanisms of action and dysregulation under various disease conditions. We also discuss the potential therapeutic applications for targeting RGS proteins in treating cardiometabolic conditions and current progress in developing RGS modulators. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Samantha M McNeill
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Peishen Zhao
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- ARC Centre for Cryo-Electron Microscopy of Membrane Proteins (CCeMMP), Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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Ye M, Fan Z, Xu Y, Luan K, Guo L, Zhang S, Luo Q. Exploring the association between fat-related traits in chickens and the RGS16 gene: insights from polymorphism and functional validation analysis. Front Vet Sci 2023; 10:1180797. [PMID: 37234072 PMCID: PMC10205986 DOI: 10.3389/fvets.2023.1180797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/24/2023] [Indexed: 05/27/2023] Open
Abstract
Introduction Excessive fat deposition in chickens can lead to reduced feed utilization and meat quality, resulting in significant economic losses for the broiler industry. Therefore, reducing fat deposition has become an important breeding objective in addition to achieving high broiler weight, growth rate, and feed conversion efficiency. In our previous studies, we observed high expression of Regulators of G Protein Signaling 16 Gene (RGS16) in high-fat individuals. This led us to speculate that RGS16 might be involved in the process of fat deposition in chickens. Methods Thus, we conducted a polymorphism and functional analysis of the RGS16 gene to investigate its association with fat-related phenotypic traits in chickens. Using a mixed linear model (MLM), this study explored the relationship between RGS16 gene polymorphisms and fat-related traits for the first time. We identified 30 SNPs of RGS16 in a population of Wens Sanhuang chickens, among which 8 SNPs were significantly associated with fat-related traits, including sebum thickness (ST), abdominal fat weight (AFW), and abdominal fat weight (AFR). Furthermore, our findings demonstrated that AFW, AFR, and ST showed significant associations with at least two or more out of the eight identified SNPs of RGS16. We also validated the role of RGS16 in ICP-1 cells through various experimental methods, including RT-qPCR, CCK- 8, EdU assays, and oil red O staining. Results Our functional validation experiments showed that RGS16 was highly expressed in the abdominal adipose tissue of high-fat chickens and played a critical role in the regulation of fat deposition by promoting preadipocyte differentiation and inhibiting their proliferation. Taken together, our findings suggest that RGS16 polymorphisms are associated with fat-related traits in chickens. Moreover, the ectopic expression of RGS16 could inhibit preadipocyte proliferation but promote preadipocyte differentiation. Discussion Based on our current findings, we propose that the RGS16 gene could serve as a powerful genetic marker for marker-assisted breeding of chicken fat-related traits.
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Affiliation(s)
- Mao Ye
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Zhexia Fan
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Yuhang Xu
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Kang Luan
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Lijin Guo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Siyu Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
| | - Qingbin Luo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, China
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Liu J, Zhu Y, Zhu D, Shi Y, Lu L, Li W, Li L, Zhou X, Zhang P, Yang H, Li M, Wang B, Sun M. GDF15 negatively regulates RGS16 to impair hepatic lipid metabolism in male mice offspring conceived by in vitro fertilization. Am J Transl Res 2022; 14:7535-7551. [PMID: 36398249 PMCID: PMC9641458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
OBJECTIVES We generated an in vitro fertilization and embryo transfer (IVF-ET) mouse model to investigate the molecular mechanism underlying the abnormal lipid metabolism found in IVF-ET offspring. METHODS The glucose metabolism levels of offspring were assessed by glucose tolerance test (GTT), insulin tolerance test (ITT), and pyruvate tolerance test (PTT). The lipid metabolism levels were assessed by triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). RNA-seq was performed on liver tissues. mRNA and protein expression of relevant genes was verified by the quantitative real-time PCR and protein immunoblotting. HepG2 cells were transfected with either interfering RNA or overexpression plasmids to investigate the gene functions. RESULTS Compared to the control, male IVF-ET offspring showed: 1) higher body, liver, and epididymal white adipose tissue weight; 2) disrupted glucolipid metabolism with abnormal GTT, ITT, and PTT; 3) significantly decreased GDF15 along with increased RGS16. Furthermore, phosphorylation of ERK1/2 and AKT was significantly reduced. In HepG2 cells, knockdown of GDF15 caused an abnormally increased RGS16 and decreased phosphorylation of ERK1/2 and AKT, accompanied by increased lipid deposition. In contrast, overexpression of GDF15 reduced expression of RGS16. Simultaneous knockdown of both GDF15 and RGS16 reversed lipid deposition. CONCLUSIONS Down-regulation of GDF15 results in elevated RGS16, which causes the weakening of the downstream ERK1/2 and AKT phosphorylation, leading to abnormal lipid metabolism in the livers of IVF-ET male offspring. This suggests that the GDF15-RGS16-p-ERK1/2/p-AKT pathway plays a crucial role in liver lipid deposition in IVF-ET male offspring and could be a therapeutic target.
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Affiliation(s)
- Jingliu Liu
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Yichen Zhu
- Cambridge-Suda Genomic Resource Center, Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Suzhou Medical College of Soochow UniversitySuzhou, Jiangsu, China
| | - Dan Zhu
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Yajun Shi
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Likui Lu
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Weisheng Li
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Lingjun Li
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Xiuwen Zhou
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Pengjie Zhang
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Hao Yang
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Min Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Bin Wang
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
| | - Miao Sun
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
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9
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Abstract
BACKGROUND Ulcerative colitis is a chronic and progressive inflammatory disorder. The regulator of the G-protein signaling (RGS) is involved in the pathogenesis of several immune system disorders. RGS16, a member of the RGS protein superfamily, has been shown to play critical roles in several immune system-related diseases. However, the roles of RGS16 in ulcerative colitis remain to be elucidated. METHODS We analyzed the expression of RGS16 in peripheral blood mononuclear cells (PBMCs) and inflamed mucosa of ulcerative colitis patients using quantitative reverse transcription-PCR, western blotting and immunohistochemistry. We performed Spearman's correlation to analyze the correlation between RGS16 expression and the ulcerative colitis endoscopic index of severity (UCEIS), Mayo index, erythrocyte sedimentation rate (ESR) and serum tumor necrosis factor alpha (TNF-a) and IL-17A levels. Further, PBMCs were stimulated with inflammatory cytokines in vitro . RESULTS RGS16 expression significantly increased in the colonic mucosa and PBMCs from patients with ulcerative colitis and significantly correlated with the Mayo index, UCEIS, ESR and serum TNF-α and IL-17A levels. TNF-α upregulated RGS16 expression in PBMCs in a dose- and time-dependent manner via the nuclear factor kappa beta (NF-kB) signaling pathway. Moreover, anti-TNF treatment with infliximab significantly decreased RGS16 expression in PBMCs and intestinal mucosa of patients with ulcerative colitis. CONCLUSION Our study revealed a novel mechanism by which RGS16 expression in ulcerative colitis is positively correlated with disease activity. Thus, RGS16 might serve as a potential therapeutic marker for the treatment of ulcerative colitis.
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10
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Stokar J, Gurt I, Cohen-Kfir E, Yakubovsky O, Hallak N, Benyamini H, Lishinsky N, Offir N, Tam J, Dresner-Pollak R. Hepatic adropin is regulated by estrogen and contributes to adverse metabolic phenotypes in ovariectomized mice. Mol Metab 2022; 60:101482. [PMID: 35364299 PMCID: PMC9044006 DOI: 10.1016/j.molmet.2022.101482] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/13/2022] [Accepted: 03/24/2022] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE Menopause is associated with visceral adiposity, hepatic steatosis and increased risk for cardiovascular disease. As estrogen replacement therapy is not suitable for all postmenopausal women, a need for alternative therapeutics and biomarkers has emerged. METHODS 9-week-old C57BL/6 J female mice were subjected to ovariectomy (OVX) or SHAM surgery (n = 10 per group), fed a standard diet and sacrificed 6- & 12 weeks post-surgery. RESULTS Increased weight gain, hepatic triglyceride content and changes in hepatic gene expression of Cyp17a1, Rgs16, Fitm1 as well as Il18, Rares2, Retn, Rbp4 in mesenteric visceral adipose tissue (VAT) were observed in OVX vs. SHAM. Liver RNA-sequencing 6-weeks post-surgery revealed changes in genes and microRNAs involved in fat metabolism in OVX vs. SHAM mice. Energy Homeostasis Associated gene (Enho) coding for the hepatokine adropin was significantly reduced in OVX mice livers and strongly inversely correlated with weight gain (r = -0.7 p < 0.001) and liver triglyceride content (r = -0.4, p = 0.04), with a similar trend for serum adropin. In vitro, Enho expression was tripled by 17β-estradiol in BNL 1 ME liver cells with increased adropin in supernatant. Analysis of open-access datasets revealed increased hepatic Enho expression in estrogen treated OVX mice and estrogen dependent ERα binding to Enho. Treatment of 5-month-old OVX mice with Adropin (i.p. 450 nmol/kg/twice daily, n = 4,5 per group) for 6-weeks reversed adverse adipokine gene expression signature in VAT, with a trended increase in lean body mass and decreased liver TG content with upregulation of Rgs16. CONCLUSIONS OVX is sufficient to induce deranged metabolism in adult female mice. Hepatic adropin is regulated by estrogen, negatively correlated with adverse OVX-induced metabolic phenotypes, which were partially reversed with adropin treatment. Adropin should be further explored as a potential therapeutic target and biomarker for menopause-related metabolic derangement.
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Affiliation(s)
- Joshua Stokar
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Irina Gurt
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Einav Cohen-Kfir
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Oran Yakubovsky
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Noa Hallak
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Hadar Benyamini
- Info-CORE, Bioinformatics Unit of the I-CORE at the Hebrew University and Hadassah Medical Center, Jerusalem, Israel
| | - Natan Lishinsky
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Neta Offir
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Joseph Tam
- Obesity and Metabolism Laboratory, The Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Rivka Dresner-Pollak
- Department of Endocrinology and Metabolism, Division of Medicine, Hadassah Medical Organization, Faculty of Medicine, Hebrew University of Jerusalem, Israel.
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11
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Weisshaar N, Wu J, Ming Y, Madi A, Hotz-Wagenblatt A, Ma S, Mieg A, Hering M, Zettl F, Mohr K, Schlimbach T, Ten Bosch N, Hertel F, Müller L, Byren H, Wang M, Borgers H, Munz M, Schmitt L, van der Hoeven F, Kloz U, Carretero R, Schleußner N, Jackstadt RF, Hofmann I, Cui G. Rgs16 promotes antitumor CD8 + T cell exhaustion. Sci Immunol 2022; 7:eabh1873. [PMID: 35622904 DOI: 10.1126/sciimmunol.abh1873] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
T cells become functionally exhausted in tumors, limiting T cell-based immunotherapies. Although several transcription factors regulating the exhausted T (Tex) cell differentiation are known, comparatively little is known about the regulators of Tex cell survival. Here, we reported that the regulator of G protein signaling 16 (Rgs-16) suppressed Tex cell survival in tumors. By performing lineage tracing using reporter mice in which mCherry marked Rgs16-expressing cells, we identified that Rgs16+CD8+ tumor-infiltrating lymphocytes (TILs) were terminally differentiated, expressed low levels of T cell factor 1 (Tcf1), and underwent apoptosis as early as 6 days after the onset of Rgs16 expression. Rgs16 deficiency inhibited CD8+ T cell apoptosis and promoted antitumor effector functions of CD8+ T cells. Furthermore, Rgs16 deficiency synergized with programmed cell death protein 1 (PD-1) blockade to enhance antitumor CD8+ T cell responses. Proteomics revealed that Rgs16 interacted with the scaffold protein IQGAP1, suppressed the recruitment of Ras and B-Raf, and inhibited Erk1 activation. Rgs16 deficiency enhanced antitumor CD8+ TIL survival in an Erk1-dependent manner. Loss of function of Erk1 decreased antitumor functions of Rgs16-deficient CD8+ T cells. RGS16 mRNA expression levels in CD8+ TILs of patients with melanoma negatively correlated with genes associated with T cell stemness, such as SELL, TCF7, and IL7R, and predicted low responses to PD-1 blockade. This study uncovers Rgs16 as an inhibitor of Tex cell survival in tumors and has implications for improving T cell-based immunotherapies.
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Affiliation(s)
- Nina Weisshaar
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Jingxia Wu
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Yanan Ming
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alaa Madi
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Agnes Hotz-Wagenblatt
- Core Facility Omics IT and Data Management, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Sicong Ma
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alessa Mieg
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Marvin Hering
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Ferdinand Zettl
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Kerstin Mohr
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Tilo Schlimbach
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Nora Ten Bosch
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Franziska Hertel
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Lisann Müller
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Hannah Byren
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Mona Wang
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Helena Borgers
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Mareike Munz
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Lukas Schmitt
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Franciscus van der Hoeven
- Transgenic Service (W450), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ulrich Kloz
- Transgenic Service (W450), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Rafael Carretero
- DKFZ-Bayer Immunotherapeutic Lab, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Nikolai Schleußner
- Cancer Progression and Metastasis (A013), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, University Heidelberg, 69120 Heidelberg, Germany
| | - Rene-Filip Jackstadt
- Cancer Progression and Metastasis (A013), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ilse Hofmann
- Division of Vascular Oncology and Metastasis (A190), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Core Facility Antibodies (W170), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Guoliang Cui
- T Cell Metabolism Group (D192), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany.,Helmholtz Institute for Translational Oncology (HI-TRON), 55131 Mainz, Germany
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12
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Mahata T, Sengar AS, Basak M, Das K, Pramanick A, Verma SK, Singh PK, Biswas S, Sarkar S, Saha S, Chatterjee S, Das M, Stewart A, Maity B. Hepatic Regulator of G Protein Signaling 6 (RGS6) drives non-alcoholic fatty liver disease by promoting oxidative stress and ATM-dependent cell death. Redox Biol 2021; 46:102105. [PMID: 34534913 PMCID: PMC8446788 DOI: 10.1016/j.redox.2021.102105] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 08/14/2021] [Indexed: 12/15/2022] Open
Abstract
The pathophysiological mechanism(s) driving non-alcoholic fatty liver disease, the most prevalent chronic liver disease globally, have yet to be fully elucidated. Here, we identify regulator of G protein signaling 6 (RGS6), up-regulated in the livers of NAFLD patients, as a critical mediator of hepatic steatosis, fibrosis, inflammation, and cell death. Human patients with high hepatic RGS6 expression exhibited a corresponding high inflammatory burden, pronounced insulin resistance, and poor liver function. In mice, liver-specific RGS6 knockdown largely ameliorated high fat diet (HFD)-driven oxidative stress, fibrotic remodeling, inflammation, lipid deposition and cell death. RGS6 depletion allowed for maintenance of mitochondrial integrity restoring redox balance, improving fatty acid oxidation, and preventing loss of insulin receptor sensitivity in hepatocytes. RGS6 is both induced by ROS and increases ROS generation acting as a key amplification node to exacerbate oxidative stress. In liver, RGS6 forms a direct complex with ATM kinase supported by key aspartate residues in the RGS domain and is both necessary and sufficient to drive hyperlipidemia-dependent ATM phosphorylation. pATM and markers of DNA damage (γH2AX) were also elevated in livers from NAFLD patients particularly in samples with high RGS6 protein content. Unsurprisingly, RGS6 knockdown prevented ATM phosphorylation in livers from HFD-fed mice. Further, RGS6 mutants lacking the capacity for ATM binding fail to facilitate palmitic acid-dependent hepatocyte apoptosis underscoring the importance of the RGS6-ATM complex in hyperlipidemia-dependent cell death. Inhibition of RGS6, then, may provide a viable means to prevent or reverse liver damage by mitigating oxidative liver damage.
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Affiliation(s)
- Tarun Mahata
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Abhishek Singh Sengar
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Madhuri Basak
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Kiran Das
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Arnab Pramanick
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Sumit Kumar Verma
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India
| | - Praveen Kumar Singh
- Department of Surgery, Millers School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Sayan Biswas
- Department of Forensic Medicine, College of Medicine and Sagore Dutta Hospital, B.T. Road, Kamarhati, Kolkata, West Bengal, 700058, India
| | - Subhasish Sarkar
- Department of Surgery, College of Medicine and Sagore Dutta Hospital, B.T. Road, Kamarhati, Kolkata, West Bengal, 700058, India
| | - Sudipta Saha
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow, Uttar Pradesh, 226025, India
| | - Suvro Chatterjee
- Department of Biotechnology, Anna University and Vascular Biology Laboratory, AU-KBC Research Centre, MIT Campus, Chennai, 600044, India
| | - Madhusudan Das
- Department of Zoology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, West Bengal, 700019, India.
| | - Adele Stewart
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Biswanath Maity
- Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus, Raebareli Road, Lucknow, Uttar Pradesh, 226014, India.
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13
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Bai X, Liao Y, Sun F, Xiao X, Fu S. Diurnal regulation of oxidative phosphorylation restricts hepatocyte proliferation and inflammation. Cell Rep 2021; 36:109659. [PMID: 34496251 DOI: 10.1016/j.celrep.2021.109659] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/14/2021] [Accepted: 08/13/2021] [Indexed: 12/13/2022] Open
Abstract
The principles guiding the diurnal organization of biological pathways remain to be fully elucidated. Here, we perturb the hepatic transcriptome through nutrient regulators (high-fat diet and mTOR signaling components) to identify enduring properties of pathway organization. Temporal separation and counter-regulation between pathways of energy metabolism and inflammation/proliferation emerge as persistent transcriptome features across animal models, and network analysis identifies the G0s2 and Rgs16 genes as potential mediators at the metabolism-inflammation interface. Mechanistically, G0s2 and Rgs16 are sequentially induced during the light phase, promoting amino acid oxidation and suppressing overall mitochondrial respiration. In their absence, sphingolipids and diacylglycerides accumulate, accompanied by hepatic inflammation and hepatocyte proliferation. Notably, the expression of G0s2 and Rgs16 is further induced in obese mouse livers, and silencing of their expression accentuates hepatic fibrosis. Therefore, diurnal regulation of energy metabolism alleviates inflammatory and proliferative stresses under physiological and pathological conditions.
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Affiliation(s)
- Xiaojie Bai
- School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Yilie Liao
- School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Fangfang Sun
- School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Xia Xiao
- School of Life Sciences, Tsinghua University, Beijing, China 100084
| | - Suneng Fu
- School of Life Sciences, Tsinghua University, Beijing, China 100084; Department of Basic Research, Guangzhou Laboratory, Guangdong, China 510005.
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14
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Zhang D, Wang S, Ospina E, Shabandri O, Lank D, Akakpo JY, Zhao Z, Yang M, Wu J, Jaeschke H, Saha P, Tong X, Yin L. Fructose Protects Against Acetaminophen-Induced Hepatotoxicity Mainly by Activating the Carbohydrate-Response Element-Binding Protein α-Fibroblast Growth Factor 21 Axis in Mice. Hepatol Commun 2021; 5:992-1008. [PMID: 34141985 PMCID: PMC8183176 DOI: 10.1002/hep4.1683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 01/08/2021] [Accepted: 01/18/2021] [Indexed: 12/28/2022] Open
Abstract
Acetaminophen (N-acetyl-para-aminophenol [APAP]) overdose is the most common cause of drug-induced liver injury in the Western world and has limited therapeutic options. As an important dietary component intake, fructose is mainly metabolized in liver, but its impact on APAP-induced liver injury is not well established. We aimed to examine whether fructose supplementation could protect against APAP-induced hepatotoxicity and to determine potential fructose-sensitive intracellular mediators. We found that both high-fructose diet feeding before APAP injection and fructose gavage after APAP injection reduced APAP-induced liver injury with a concomitant induction of the hepatic carbohydrate-response element-binding protein α (ChREBPα)-fibroblast growth factor 21 (FGF21) pathway. In contrast, Chrebpα liver-specific-knockout (Chrebpα-LKO) mice failed to respond to fructose following APAP overdose, suggesting that ChREBPα is the essential intracellular mediator of fructose-induced hepatoprotective action. Primary mouse hepatocytes with deletion of Fgf21 also failed to show fructose protection against APAP hepatotoxicity. Furthermore, overexpression of FGF21 in the liver was sufficient to reverse liver toxicity in APAP-injected Chrebpα-LKO mice. Conclusion: Fructose protects against APAP-induced hepatotoxicity likely through its ability to activate the hepatocyte ChREBPα-FGF21 axis.
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Affiliation(s)
- Deqiang Zhang
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Sujuan Wang
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Erin Ospina
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Omar Shabandri
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Daniel Lank
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Jephte Y Akakpo
- Department of PharmacologyToxicology, and TherapeuticsUniversity of Kansas Medical CenterKansas CityKSUSA
| | - Zifeng Zhao
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Meichan Yang
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Jun Wu
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA.,Life Sciences InstituteUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Hartmut Jaeschke
- Department of PharmacologyToxicology, and TherapeuticsUniversity of Kansas Medical CenterKansas CityKSUSA
| | - Pradip Saha
- Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
| | - Xin Tong
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
| | - Lei Yin
- Department of Molecular and Integrative PhysiologyUniversity of Michigan Medical SchoolAnn ArborMIUSA
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15
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Yang M, Zhang CY. G protein-coupled receptors as potential targets for nonalcoholic fatty liver disease treatment. World J Gastroenterol 2021; 27:677-691. [PMID: 33716447 PMCID: PMC7934005 DOI: 10.3748/wjg.v27.i8.677] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/24/2020] [Accepted: 01/21/2021] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a broad-spectrum disease, ranging from simple hepatic steatosis to nonalcoholic steatohepatitis, which can progress to cirrhosis and liver cancer. Abnormal hepatic lipid accumulation is the major manifestation of this disease, and lipotoxicity promotes NAFLD progression. In addition, intermediate metabolites such as succinate can stimulate the activation of hepatic stellate cells to produce extracellular matrix proteins, resulting in progression of NAFLD to fibrosis and even cirrhosis. G protein-coupled receptors (GPCRs) have been shown to play essential roles in metabolic disorders, such as NAFLD and obesity, through their function as receptors for bile acids and free fatty acids. In addition, GPCRs link gut microbiota-mediated connections in a variety of diseases, such as intestinal diseases, hepatic steatosis, diabetes, and cardiovascular diseases. The latest findings show that gut microbiota-derived acetate contributes to liver lipogenesis by converting dietary fructose into hepatic acetyl-CoA and fatty acids. GPCR agonists, including peptides and natural products like docosahexaenoic acid, have been applied to investigate their role in liver diseases. Therapies such as probiotics and GPCR agonists may be applied to modulate GPCR function to ameliorate liver metabolism syndrome. This review summarizes the current findings regarding the role of GPCRs in the development and progression of NAFLD and describes some preclinical and clinical studies of GPCR-mediated treatment. Overall, understanding GPCR-mediated signaling in liver disease may provide new therapeutic options for NAFLD.
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Affiliation(s)
- Ming Yang
- Department of Surgery, University of Missouri, Columbia, MO 65212, United States
| | - Chun-Ye Zhang
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65212, United States
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16
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Morral N, Liu S, Conteh AM, Chu X, Wang Y, Dong XC, Liu Y, Linnemann AK, Wan J. Aberrant gene expression induced by a high fat diet is linked to H3K9 acetylation in the promoter-proximal region. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2021; 1864:194691. [PMID: 33556624 DOI: 10.1016/j.bbagrm.2021.194691] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/22/2021] [Accepted: 01/30/2021] [Indexed: 12/13/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, with an estimated global prevalence of 1 in 4 individuals. Aberrant transcriptional control of gene expression is central to the pathophysiology of metabolic diseases. However, the molecular mechanisms leading to gene dysregulation are not well understood. Histone modifications play important roles in the control of transcription. Acetylation of histone 3 at lysine 9 (H3K9ac) is associated with transcriptional activity and is implicated in transcript elongation by controlling RNA polymerase II (RNAPII) pause-release. Hence, changes in this histone modification may shed information on novel pathways linking transcription control and metabolic dysfunction. Here, we carried out genome-wide analysis of H3K9ac in the liver of mice fed a control or a high-fat diet (an animal model of NAFLD), and asked whether this histone mark associates with changes in gene expression. We found that over 70% of RNAPII peaks in promoter-proximal regions overlapped with H3K9ac, consistent with a role of H3K9ac in the regulation of transcription. When comparing high-fat with control diet, approximately 17% of the differentially expressed genes were associated with changes in H3K9ac in their promoters, showing a strong correlation between changes in H3K9ac signal and gene expression. Overall, our data indicate that in response to a high-fat diet, dysregulated gene expression of a subset of genes may be attributable to changes in transcription elongation driven by H3K9ac. Our results point at an added mechanism of gene regulation that may be important in the development of metabolic diseases.
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Affiliation(s)
- Núria Morral
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America.
| | - Sheng Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Abass M Conteh
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Xiaona Chu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Yue Wang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - X Charlie Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Amelia K Linnemann
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America; Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Jun Wan
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States of America; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, United States of America
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17
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Rojas IY, Moyer BJ, Ringelberg CS, Wilkins OM, Pooler DB, Ness DB, Coker S, Tosteson TD, Lewis LD, Chamberlin MD, Tomlinson CR. Kynurenine-Induced Aryl Hydrocarbon Receptor Signaling in Mice Causes Body Mass Gain, Liver Steatosis, and Hyperglycemia. Obesity (Silver Spring) 2021; 29:337-349. [PMID: 33491319 PMCID: PMC10782555 DOI: 10.1002/oby.23065] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The aryl hydrocarbon receptor (AHR) plays a key role in obesity. In vitro studies revealed that the tryptophan metabolite kynurenine (Kyn) activates AHR signaling in cultured hepatocytes. The objective of this study was to determine whether Kyn activated the AHR in mice to induce obesity. METHODS Mice were fed a low-fat diet and the same diet supplemented with Kyn. Body mass, liver status, and the expression of identified relevant genes were determined. RESULTS Kyn caused mice to gain significant body mass, develop fatty liver and hyperglycemia, and increase expression levels of cytochrome P450 1B1 and stearoyl-CoA desaturase 1. The hyperglycemia was accompanied with decreased insulin levels, which may have been due to the repression of genes involved in insulin secretion. Kyn plasma concentrations and BMI were measured in female patients, and a significant association was observed between Kyn and age in patients with obesity but not in patients who were lean. CONCLUSIONS Results show that (1) Kyn or a metabolite thereof is a ligand responsible for inducing AHR-based obesity, fatty liver, and hyperglycemia in mice; (2) plasma Kyn levels increase with age in women with obesity but not in lean women; and (3) an activated AHR is necessary but not sufficient to attain obesity, a status that also requires fat in the diet.
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Affiliation(s)
- Itzel Y. Rojas
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Benjamin J. Moyer
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Carol S. Ringelberg
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Owen M. Wilkins
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Darcy B. Pooler
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Dylan B. Ness
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Shodeinde Coker
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Tor D. Tosteson
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Department of Biomedical Data Science, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Lionel D. Lewis
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Mary D. Chamberlin
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Craig R. Tomlinson
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
- Department of Molecular & Systems Biology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
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18
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Xia C, Zhang X, Cao T, Wang J, Li C, Yue L, Niu K, Shen Y, Ma G, Chen F. Hepatic Transcriptome Analysis Revealing the Molecular Pathogenesis of Type 2 Diabetes Mellitus in Zucker Diabetic Fatty Rats. Front Endocrinol (Lausanne) 2020; 11:565858. [PMID: 33329383 PMCID: PMC7732450 DOI: 10.3389/fendo.2020.565858] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/22/2020] [Indexed: 01/22/2023] Open
Abstract
Around 9% of the adult population in the world (463 million) suffer from diabetes mellitus. Most of them (~90%) belong to type 2 diabetes mellitus (T2DM), which is a common chronic metabolic disorder, and the number of cases has been reported to increase each year. Zucker diabetic fatty (ZDF) rat provides a successful animal model to study the pathogenesis of T2DM. Although previous hepatic transcriptome studies revealed some novel genes associated with the occurrence and development of T2DM, there still lacks the comprehensive transcriptomic analysis for the liver tissues of ZDF rats. We performed comparative transcriptome analyses between the liver tissues of ZDF rats and healthy ZCL rats and also evaluated several clinical indices. We could identify 214 and 104 differentially expressed genes (DEGs) and lncRNAs in ZDF rats, respectively. Pathway and biofunction analyses showed a synergistic effect between mRNAs and lncRNAs. By comprehensively analyzing transcriptomic data and clinical indices, we detected some typical features of T2DM in ZDF rats, such as upregulated metabolism (significant increased lipid absorption/transport/utilization, gluconeogenesis, and protein hydrolysis), increased inflammation, liver injury and increased endoplasmic reticulum (ER) stress. In addition, of the 214 DEGs, 114 were known and 100 were putative T2DM-related genes, most of which have been associated with substance metabolism (particularly degradation), inflammation, liver injury and ER stress biofunctions. Our study provides an important reference and improves understanding of molecular pathogenesis of obesity-associated T2DM. Our data can also be used to identify potential diagnostic markers and therapeutic targets, which should strengthen the prevention and treatment of T2DM.
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Affiliation(s)
- Chengdong Xia
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiuli Zhang
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Tianshu Cao
- Department of Virology, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jiannong Wang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Cuidan Li
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Liya Yue
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Kaifeng Niu
- China National Center for Bioinformation, Beijing, China
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Yicheng Shen
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guannan Ma
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Fei Chen
- China National Center for Bioinformation, Beijing, China
- CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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19
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Lei Y, Hoogerland JA, Bloks VW, Bos T, Bleeker A, Wolters H, Wolters JC, Hijmans BS, van Dijk TH, Thomas R, van Weeghel M, Mithieux G, Houtkooper RH, de Bruin A, Rajas F, Kuipers F, Oosterveer MH. Hepatic Carbohydrate Response Element Binding Protein Activation Limits Nonalcoholic Fatty Liver Disease Development in a Mouse Model for Glycogen Storage Disease Type 1a. Hepatology 2020; 72:1638-1653. [PMID: 32083759 PMCID: PMC7702155 DOI: 10.1002/hep.31198] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/29/2020] [Accepted: 02/03/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND AIMS Glycogen storage disease (GSD) type 1a is an inborn error of metabolism caused by defective glucose-6-phosphatase catalytic subunit (G6PC) activity. Patients with GSD 1a exhibit severe hepatomegaly due to glycogen and triglyceride (TG) accumulation in the liver. We have shown that the activity of carbohydrate response element binding protein (ChREBP), a key regulator of glycolysis and de novo lipogenesis, is increased in GSD 1a. In the current study, we assessed the contribution of ChREBP to nonalcoholic fatty liver disease (NAFLD) development in a mouse model for hepatic GSD 1a. APPROACH AND RESULTS Liver-specific G6pc-knockout (L-G6pc-/- ) mice were treated with adeno-associated viruses (AAVs) 2 or 8 directed against short hairpin ChREBP to normalize hepatic ChREBP activity to levels observed in wild-type mice receiving AAV8-scrambled short hairpin RNA (shSCR). Hepatic ChREBP knockdown markedly increased liver weight and hepatocyte size in L-G6pc-/- mice. This was associated with hepatic accumulation of G6P, glycogen, and lipids, whereas the expression of glycolytic and lipogenic genes was reduced. Enzyme activities, flux measurements, hepatic metabolite analysis and very low density lipoprotein (VLDL)-TG secretion assays revealed that hepatic ChREBP knockdown reduced downstream glycolysis and de novo lipogenesis but also strongly suppressed hepatic VLDL lipidation, hence promoting the storage of "old fat." Interestingly, enhanced VLDL-TG secretion in shSCR-treated L-G6pc-/- mice associated with a ChREBP-dependent induction of the VLDL lipidation proteins microsomal TG transfer protein and transmembrane 6 superfamily member 2 (TM6SF2), the latter being confirmed by ChIP-qPCR. CONCLUSIONS Attenuation of hepatic ChREBP induction in GSD 1a liver aggravates hepatomegaly because of further accumulation of glycogen and lipids as a result of reduced glycolysis and suppressed VLDL-TG secretion. TM6SF2, critical for VLDL formation, was identified as a ChREBP target in mouse liver. Altogether, our data show that enhanced ChREBP activity limits NAFLD development in GSD 1a by balancing hepatic TG production and secretion.
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Affiliation(s)
- Yu Lei
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Joanne A. Hoogerland
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Vincent W. Bloks
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Trijnie Bos
- Department of Laboratory MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Aycha Bleeker
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Henk Wolters
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Justina C. Wolters
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Brenda S. Hijmans
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Theo H. van Dijk
- Department of Laboratory MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Rachel Thomas
- Dutch Molecular Pathology CenterFaculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Michel van Weeghel
- Laboratory Genetic Metabolic DiseasesAmsterdam Gastroenterology and MetabolismAmsterdam Cardiovascular SciencesAmsterdamthe Netherlands
- Core Facility of MetabolomicsAmsterdam University Medical CenterUniversity of AmsterdamAmsterdamthe Netherlands
| | - Gilles Mithieux
- National Institute of Health and Medical Research, U1213LyonFrance
- University of LyonLyonFrance
- University of Lyon 1VilleurbanneFrance
| | - Riekelt H. Houtkooper
- Laboratory Genetic Metabolic DiseasesAmsterdam Gastroenterology and MetabolismAmsterdam Cardiovascular SciencesAmsterdamthe Netherlands
| | - Alain de Bruin
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
- Dutch Molecular Pathology CenterFaculty of Veterinary MedicineUtrecht UniversityUtrechtthe Netherlands
| | - Fabienne Rajas
- National Institute of Health and Medical Research, U1213LyonFrance
- University of LyonLyonFrance
- University of Lyon 1VilleurbanneFrance
| | - Folkert Kuipers
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
- Department of Laboratory MedicineUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
| | - Maaike H. Oosterveer
- Department of PediatricsUniversity Medical Center GroningenUniversity of GroningenGroningenthe Netherlands
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20
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Genome-wide association study for circulating fibroblast growth factor 21 and 23. Sci Rep 2020; 10:14578. [PMID: 32884031 PMCID: PMC7471933 DOI: 10.1038/s41598-020-71569-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 08/06/2020] [Indexed: 11/09/2022] Open
Abstract
Fibroblast growth factors (FGFs) 21 and 23 are recently identified hormones regulating metabolism of glucose, lipid, phosphate and vitamin D. Here we conducted a genome-wide association study (GWAS) for circulating FGF21 and FGF23 concentrations to identify their genetic determinants. We enrolled 5,000 participants from Taiwan Biobank for this GWAS. After excluding participants with diabetes mellitus and quality control, association of single nucleotide polymorphisms (SNPs) with log-transformed FGF21 and FGF23 serum concentrations adjusted for age, sex and principal components of ancestry were analyzed. A second model additionally adjusted for body mass index (BMI) and a third model additionally adjusted for BMI and estimated glomerular filtration rate (eGFR) were used. A total of 4,201 participants underwent GWAS analysis. rs67327215, located within RGS6 (a gene involved in fatty acid synthesis), and two other SNPs (rs12565114 and rs9520257, located between PHC2-ZSCAN20 and ARGLU1-FAM155A respectively) showed suggestive associations with serum FGF21 level (P = 6.66 × 10–7, 6.00 × 10–7 and 6.11 × 10–7 respectively). The SNPs rs17111495 and rs17843626 were significantly associated with FGF23 level, with the former near PCSK9 gene and the latter near HLA-DQA1 gene (P = 1.04 × 10–10 and 1.80 × 10–8 respectively). SNP rs2798631, located within the TGFB2 gene, was suggestively associated with serum FGF23 level (P = 4.97 × 10–7). Additional adjustment for BMI yielded similar results. For FGF23, further adjustment for eGFR had similar results. We conducted the first GWAS of circulating FGF21 levels to date. Novel candidate genetic loci associated with circulating FGF21 or FGF23 levels were found. Further replication and functional studies are needed to support our findings.
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21
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Tommasi S, Yoon JI, Besaratinia A. Secondhand Smoke Induces Liver Steatosis through Deregulation of Genes Involved in Hepatic Lipid Metabolism. Int J Mol Sci 2020; 21:E1296. [PMID: 32075112 PMCID: PMC7072934 DOI: 10.3390/ijms21041296] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/05/2020] [Accepted: 02/13/2020] [Indexed: 12/24/2022] Open
Abstract
We investigated the role of secondhand smoke (SHS) exposure, independently of diet, in the development of chronic liver disease. Standard diet-fed mice were exposed to SHS (5 h/day, 5 days/week for 4 months). Genome-wide gene expression analysis, together with molecular pathways and gene network analyses, and histological examination for lipid accumulation, inflammation, fibrosis, and glycogen deposition were performed on the liver of SHS-exposed mice and controls, upon termination of exposure and after one-month recovery in clean air. Aberrantly expressed transcripts were found in the liver of SHS-exposed mice both pre- and post-recovery in clean air (n = 473 vs. 222). The persistent deregulated transcripts (n = 210) predominantly affected genes and functional networks involved in lipid metabolism as well as in the regulation of the endoplasmic reticulum where manufacturing of lipids occurs. Significant hepatic fat accumulation (steatosis) was observed in the SHS-exposed mice, which progressively increased as the animals underwent recovery in clean air. Moderate increases in lobular inflammation infiltrates and collagen deposition as well as loss of glycogen were also detectable in the liver of SHS-exposed mice. A more pronounced phenotype, manifested as a disrupted cord-like architecture with foci of necrosis, apoptosis, inflammation, and macrovesicular steatosis, was observed in the liver of SHS-exposed mice post-recovery. The progressive accumulation of hepatic fat and other adverse histological changes in the SHS-exposed mice are highly consistent with the perturbation of key lipid genes and associated pathways in the corresponding animals. Our data support a role for SHS in the genesis and progression of metabolic liver disease through deregulation of genes and molecular pathways and functional networks involved in lipid homeostasis.
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Affiliation(s)
- Stella Tommasi
- Department of Preventive Medicine, USC Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
| | - Jae-In Yoon
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA;
| | - Ahmad Besaratinia
- Department of Preventive Medicine, USC Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
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22
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Hepatic arginase 2 (Arg2) is sufficient to convey the therapeutic metabolic effects of fasting. Nat Commun 2019; 10:1587. [PMID: 30962478 PMCID: PMC6453920 DOI: 10.1038/s41467-019-09642-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 03/22/2019] [Indexed: 02/08/2023] Open
Abstract
Caloric restriction and intermittent fasting are emerging therapeutic strategies against obesity, insulin resistance and their complications. However, the effectors that drive this response are not completely defined. Here we identify arginase 2 (Arg2) as a fasting-induced hepatocyte factor that protects against hepatic and peripheral fat accumulation, hepatic inflammatory responses, and insulin and glucose intolerance in obese murine models. Arg2 is upregulated in fasting conditions and upon treatment with the hepatocyte glucose transporter inhibitor trehalose. Hepatocyte-specific Arg2 overexpression enhances basal thermogenesis, and protects from weight gain, insulin resistance, glucose intolerance, hepatic steatosis and hepatic inflammation in diabetic mouse models. Arg2 suppresses expression of the regulator of G-protein signalling (RGS) 16, and genetic RGS16 reconstitution reverses the effects of Arg2 overexpression. We conclude that hepatocyte Arg2 is a critical effector of the hepatic glucose fasting response and define a therapeutic target to mitigate the complications of obesity and non-alcoholic fatty liver disease. Fasting is known for its beneficial effects on obesity and diabetes-related health complications. Here Zhang et al. show that fasting induces expression of arginase-2 (Arg2) in the liver, and that hepatic Arg2, by suppressing the expression of the regulator of G-protein signalling 16, recapitulates the positive effects of fasting in obesity and diabetes.
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23
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Perschbacher KJ, Deng G, Fisher RA, Gibson-Corley KN, Santillan MK, Grobe JL. Regulators of G protein signaling in cardiovascular function during pregnancy. Physiol Genomics 2018; 50:590-604. [PMID: 29702036 PMCID: PMC6139632 DOI: 10.1152/physiolgenomics.00037.2018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
G protein-coupled receptor signaling mechanisms are implicated in many aspects of cardiovascular control, and dysfunction of such signaling mechanisms is commonly associated with disease states. Investigators have identified a large number of regulator of G protein signaling (RGS) proteins that variously contribute to the modulation of intracellular second-messenger signaling kinetics. These many RGS proteins each interact with a specific set of second-messenger cascades and receptor types and exhibit tissue-specific expression patterns. Increasing evidence supports the contribution of RGS proteins, or their loss, in the pathogenesis of cardiovascular dysfunctions. This review summarizes the current understanding of the functional contributions of RGS proteins, particularly within the B/R4 family, in cardiovascular disorders of pregnancy including gestational hypertension, uterine artery dysfunction, and preeclampsia.
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Affiliation(s)
| | - Guorui Deng
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
| | - Rory A Fisher
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
| | - Katherine N Gibson-Corley
- Department of Pathology, University of Iowa , Iowa City, Iowa
- UIHC Center for Hypertension Research, University of Iowa , Iowa City, Iowa
| | - Mark K Santillan
- Department of Obstetrics & Gynecology, University of Iowa , Iowa City, Iowa
- UIHC Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- Abboud Cardiovascular Research Center, University of Iowa , Iowa City, Iowa
| | - Justin L Grobe
- Department of Pharmacology, University of Iowa , Iowa City, Iowa
- UIHC Center for Hypertension Research, University of Iowa , Iowa City, Iowa
- Abboud Cardiovascular Research Center, University of Iowa , Iowa City, Iowa
- Fraternal Order of Eagles' Diabetes Research Center, University of Iowa , Iowa City, Iowa
- Obesity Education & Research Initiative, University of Iowa , Iowa City, Iowa
- Iowa Neuroscience Institute, University of Iowa , Iowa City, Iowa
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24
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Li CY, Cui JY. Regulation of protein-coding gene and long noncoding RNA pairs in liver of conventional and germ-free mice following oral PBDE exposure. PLoS One 2018; 13:e0201387. [PMID: 30067809 PMCID: PMC6070246 DOI: 10.1371/journal.pone.0201387] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 07/14/2018] [Indexed: 02/07/2023] Open
Abstract
Gut microbiome communicates with the host liver to modify hepatic xenobiotic biotransformation and nutrient homeostasis. Polybrominated diphenyl ethers (PBDEs) are persistent environmental contaminants that are detected in fatty food, household dust, and human breast milk at worrisome levels. Recently, long noncoding RNAs (lncRNAs) have been recognized as novel biomarkers for toxicological responses and may regulate the transcriptional/translational output of protein-coding genes (PCGs). However, very little is known regarding to what extent the interactions between PBDEs and gut microbiome modulate hepatic lncRNAs and PCGs, and what critical signaling pathways are impacted at the transcriptomic scale. In this study, we performed RNA-Seq in livers of nine-week-old male conventional (CV) and germ-free (GF) mice orally exposed to the most prevalent PBDE congeners BDE-47 and BDE-99 (100 μmol/kg once daily for 4-days; vehicle: corn oil, 10 ml/kg), and unveiled key molecular pathways and PCG-lncRNA pairs targeted by PBDE-gut microbiome interactions. Lack of gut microbiome profoundly altered the PBDE-mediated transcriptomic response in liver, with the most prominent effect observed in BDE-99-exposed GF mice. The top pathways up-regulated by PBDEs were related to xenobiotic metabolism, whereas the top pathways down-regulated by PBDEs were in lipid metabolism and protein synthesis in both enterotypes. Genomic annotation of the differentially regulated lncRNAs revealed that majority of these lncRNAs overlapped with introns and 3'-UTRs of PCGs. Lack of gut microbiome profoundly increased the percentage of PBDE-regulated lncRNAs mapped to the 3'-UTRs of PCGs, suggesting the potential involvement of lncRNAs in increasing the translational efficiency of PCGs by preventing miRNA-3'-UTR binding, as a compensatory mechanism following toxic exposure to PBDEs. Pathway analysis of PCGs paired with lncRNAs revealed that in CV mice, BDE-47 regulated nucleic acid and retinol metabolism, as well as circadian rhythm; whereas BDE-99 regulated fatty acid metabolism. In GF mice, BDE-47 differentially regulated 19 lncRNA-PCG pairs that were associated with glutathione conjugation and transcriptional regulation. In contrast, BDE-99 up-regulated the xenobiotic-metabolizing Cyp3a genes, but down-regulated the fatty acid-metabolizing Cyp4 genes. Taken together, the present study reveals common and unique lncRNAs and PCG targets of PBDEs in mouse liver, and is among the first to show that lack of gut microbiome sensitizes the liver to toxic exposure of BDE-99 but not BDE-47. Therefore, lncRNAs may serve as specific biomarkers that differentiate various PBDE congeners as well as environmental chemical-mediated dysbiosis. Coordinate regulation of PCG-lncRNA pairs may serve as a more efficient molecular mechanism to combat against xenobiotic insult, and especially during dysbiosis-induced increase in the internal dose of toxicants.
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Affiliation(s)
- Cindy Yanfei Li
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Julia Yue Cui
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
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25
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Squires KE, Montañez-Miranda C, Pandya RR, Torres MP, Hepler JR. Genetic Analysis of Rare Human Variants of Regulators of G Protein Signaling Proteins and Their Role in Human Physiology and Disease. Pharmacol Rev 2018; 70:446-474. [PMID: 29871944 PMCID: PMC5989036 DOI: 10.1124/pr.117.015354] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Regulators of G protein signaling (RGS) proteins modulate the physiologic actions of many neurotransmitters, hormones, and other signaling molecules. Human RGS proteins comprise a family of 20 canonical proteins that bind directly to G protein-coupled receptors/G protein complexes to limit the lifetime of their signaling events, which regulate all aspects of cell and organ physiology. Genetic variations account for diverse human traits and individual predispositions to disease. RGS proteins contribute to many complex polygenic human traits and pathologies such as hypertension, atherosclerosis, schizophrenia, depression, addiction, cancers, and many others. Recent analysis indicates that most human diseases are due to extremely rare genetic variants. In this study, we summarize physiologic roles for RGS proteins and links to human diseases/traits and report rare variants found within each human RGS protein exome sequence derived from global population studies. Each RGS sequence is analyzed using recently described bioinformatics and proteomic tools for measures of missense tolerance ratio paired with combined annotation-dependent depletion scores, and protein post-translational modification (PTM) alignment cluster analysis. We highlight selected variants within the well-studied RGS domain that likely disrupt RGS protein functions and provide comprehensive variant and PTM data for each RGS protein for future study. We propose that rare variants in functionally sensitive regions of RGS proteins confer profound change-of-function phenotypes that may contribute, in newly appreciated ways, to complex human diseases and/or traits. This information provides investigators with a valuable database to explore variation in RGS protein function, and for targeting RGS proteins as future therapeutic targets.
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Affiliation(s)
- Katherine E Squires
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Carolina Montañez-Miranda
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Rushika R Pandya
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - Matthew P Torres
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
| | - John R Hepler
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia (K.E.S., C.M.-M., J.R.H.); and School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia (R.R.P., M.P.T.)
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Malnutrition in Pancreatic Ductal Adenocarcinoma (PDA): Dietary Pancreatic Enzymes Improve Short-Term Health but Stimulate Tumor Growth. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:616-626. [PMID: 29248457 DOI: 10.1016/j.ajpath.2017.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/20/2017] [Accepted: 11/09/2017] [Indexed: 02/07/2023]
Abstract
Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer that resists efforts to identify better chemotherapeutics. PDA is associated with chronic pancreatitis and acinar cell dedifferentiation. This reduces enzyme production by the exocrine pancreas, resulting in digestive insufficiencies. Malabsorption of partially digested food causes bloating, overfilled intestines, abdominal pain, excessive feces, steatorrhea, and malnutrition. These maladies affect quality of life and restrict treatment options for pancreatitis and PDA. Here, we characterize health benefits and risks of dietary pancreatic enzymes in three mouse models of PDA-KC, KCR8-16, and KIC. KC expresses oncogenic KrasG12D in pancreatic tissue whereas KCR8-16 also has deletions of the Rgs8 and Rgs16 genes. Rgs proteins inhibit the release of digestive enzymes evoked by G-protein-coupled-receptor agonists. KC and KCR8-16 mice developed dedifferentiated exocrine pancreata within 2 months of age and became malnourished, underweight, hypoglycemic, and hypothermic. KC mice adapted but KCR8-16 mice rapidly transitioned to starvation after mild metabolic challenges. Dietary pancreatic enzyme supplements reversed these symptoms in KC and KCR8-16 animals, and extended survival. Therefore, we tested the benefits of pancreatic enzymes in an aggressive mouse model of PDA (KIC). Median survival improved with dietary pancreatic enzyme supplements and was extended further when combined with warfarin and gemcitabine chemotherapy. However, dietary pancreatic enzymes stimulated tumor growth in the terminal stages of disease progression in KIC mice.
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Baked corn ( Zea mays L.) and bean ( Phaseolus vulgaris L.) snack consumption lowered serum lipids and differentiated liver gene expression in C57BL/6 mice fed a high-fat diet by inhibiting PPARγ and SREBF2. J Nutr Biochem 2017; 50:1-15. [DOI: 10.1016/j.jnutbio.2017.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/28/2017] [Accepted: 08/21/2017] [Indexed: 12/28/2022]
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Retinol saturase coordinates liver metabolism by regulating ChREBP activity. Nat Commun 2017; 8:384. [PMID: 28855500 PMCID: PMC5577314 DOI: 10.1038/s41467-017-00430-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 06/28/2017] [Indexed: 11/09/2022] Open
Abstract
The liver integrates multiple metabolic pathways to warrant systemic energy homeostasis. An excessive lipogenic flux due to chronic dietary stimulation contributes to the development of hepatic steatosis, dyslipidemia and hyperglycemia. Here we show that the oxidoreductase retinol saturase (RetSat) is involved in the development of fatty liver. Hepatic RetSat expression correlates with steatosis and serum triglycerides (TGs) in humans. Liver-specific depletion of RetSat in dietary obese mice lowers hepatic and circulating TGs and normalizes hyperglycemia. Mechanistically, RetSat depletion reduces the activity of carbohydrate response element binding protein (ChREBP), a cellular hexose-phosphate sensor and inducer of lipogenesis. Defects upon RetSat depletion are rescued by ectopic expression of ChREBP but not by its putative enzymatic product 13,14-dihydroretinol, suggesting that RetSat affects hepatic glucose sensing independent of retinol conversion. Thus, RetSat is a critical regulator of liver metabolism functioning upstream of ChREBP. Pharmacological inhibition of liver RetSat may represent a therapeutic approach for steatosis.Fatty liver is one of the major features of metabolic syndrome and its development is associated with deregulation of systemic lipid and glucose homeostasis. Here Heidenreich et al. show that retinol saturase is implicated in hepatic lipid metabolism by regulating the activity of the transcription factor ChREBP.
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Bisphenol-A exposure in utero programs a sexually dimorphic estrogenic state of hepatic metabolic gene expression. Reprod Toxicol 2017; 71:84-94. [DOI: 10.1016/j.reprotox.2017.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 04/12/2017] [Accepted: 05/01/2017] [Indexed: 01/09/2023]
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Sae-Lee C, Moolsuwan K, Chan L, Poungvarin N. ChREBP Regulates Itself and Metabolic Genes Implicated in Lipid Accumulation in β-Cell Line. PLoS One 2016; 11:e0147411. [PMID: 26808438 PMCID: PMC4725739 DOI: 10.1371/journal.pone.0147411] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/04/2016] [Indexed: 12/20/2022] Open
Abstract
Carbohydrate response element binding protein (ChREBP) is an important transcription factor that regulates a variety of glucose-responsive genes in hepatocytes. To date, only two natural isoforms, Chrebpα and Chrebpβ, have been identified. Although ChREBP is known to be expressed in pancreatic β cells, most of the glucose-responsive genes have never been verified as ChREBP targets in this organ. We aimed to explore the impact of ChREBP expression on regulating genes linked to accumulation of lipid droplets, a typical feature of β-cell glucotoxicity. We assessed gene expression in 832/13 cells overexpressing constitutively active ChREBP (caChREBP), truncated ChREBP with nearly identical amino acid sequence to Chrebpβ, or dominant negative ChREBP (dnChREBP). Among multiple ChREBP-controlled genes, ChREBP was sufficient and necessary for regulation of Eno1, Pklr, Mdh1, Me1, Pdha1, Acly, Acaca, Fasn, Elovl6, Gpd1, Cpt1a, Rgs16, Mid1ip1,Txnip, and Chrebpβ. Expression of Chrebpα and Srebp1c were not changed by caChREBP or dnChREBP. We identified functional ChREBP binding sequences that were located on the promoters of Chrebpβ and Rgs16. We also showed that Rgs16 overexpression lead to increased considerable amounts of lipids in 832/13 cells. This phenotype was accompanied by reduction of Cpt1a expression and slight induction of Fasn and Pklr gene in these cells. In summary, we conclude that Chrebpβ modulates its own expression, not that of Chrebpα; it also regulates the expression of several metabolic genes in β-cells without affecting SREBP-1c dependent regulation. We also demonstrate that Rgs16 is one of the ChREBP-controlled genes that potentiate accumulation of lipid droplets in β-cells.
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Affiliation(s)
- Chanachai Sae-Lee
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Kanya Moolsuwan
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Molecular Medicine Program, Multidisciplinary Unit, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Lawrence Chan
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Naravat Poungvarin
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- * E-mail:
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Studer P, da Silva CG, Revuelta Cervantes JM, Mele A, Csizmadia E, Siracuse JJ, Damrauer SM, Peterson CR, Candinas D, Stroka DM, Ma A, Bhasin M, Ferran C. Significant lethality following liver resection in A20 heterozygous knockout mice uncovers a key role for A20 in liver regeneration. Cell Death Differ 2015; 22:2068-77. [PMID: 25976305 PMCID: PMC4816110 DOI: 10.1038/cdd.2015.52] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 02/24/2015] [Accepted: 03/13/2015] [Indexed: 12/14/2022] Open
Abstract
Hepatic expression of A20, including in hepatocytes, increases in response to injury, inflammation and resection. This increase likely serves a hepatoprotective purpose. The characteristic unfettered liver inflammation and necrosis in A20 knockout mice established physiologic upregulation of A20 as integral to the anti-inflammatory and anti-apoptotic armamentarium of hepatocytes. However, the implication of physiologic upregulation of A20 in modulating hepatocytes' proliferative responses following liver resection remains controversial. To resolve the impact of A20 on hepatocyte proliferation and the liver's regenerative capacity, we examined whether decreased A20 expression, as in A20 heterozygous knockout mice, affects outcome following two-third partial hepatectomy. A20 heterozygous mice do not demonstrate a striking liver phenotype, indicating that their A20 expression levels are still sufficient to contain inflammation and cell death at baseline. However, usually benign partial hepatectomy provoked a staggering lethality (>40%) in these mice, uncovering an unsuspected phenotype. Heightened lethality in A20 heterozygous mice following partial hepatectomy resulted from impaired hepatocyte proliferation due to heightened levels of cyclin-dependent kinase inhibitor, p21, and deficient upregulation of cyclins D1, E and A, in the context of worsened liver steatosis. A20 heterozygous knockout minimally affected baseline liver transcriptome, mostly circadian rhythm genes. Nevertheless, this caused differential expression of >1000 genes post hepatectomy, hindering lipid metabolism, bile acid biosynthesis, insulin signaling and cell cycle, all critical cellular processes for liver regeneration. These results demonstrate that mere reduction of A20 levels causes worse outcome post hepatectomy than full knockout of bona fide liver pro-regenerative players such as IL-6, clearly ascertaining A20's primordial role in enabling liver regeneration. Clinical implications of these data are of utmost importance as they caution safety of extensive hepatectomy for donation or tumor in carriers of A20/TNFAIP3 single nucleotide polymorphisms alleles that decrease A20 expression or function, and prompt the development of A20-based liver pro-regenerative therapies.
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Affiliation(s)
- P Studer
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Department of Visceral Surgery and Medicine, University Hospital Bern, Bern, Switzerland
| | - C G da Silva
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - J M Revuelta Cervantes
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - A Mele
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - E Csizmadia
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - J J Siracuse
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - S M Damrauer
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - C R Peterson
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - D Candinas
- Department of Visceral Surgery and Medicine, University Hospital Bern, Bern, Switzerland
| | - D M Stroka
- Department of Visceral Surgery and Medicine, University Hospital Bern, Bern, Switzerland
| | - A Ma
- Division of Interdisciplinary Medicine and Biotechnology, Bioinformatics core, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - M Bhasin
- Division of Gastroenterology, Department of Medicine, University of California in San Francisco, San Fransisco, CA, USA
| | - C Ferran
- Division of Vascular Surgery, Center for Vascular biology Research and the Transplant Institute, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Barrientos T, Laothamatas I, Koves TR, Soderblom EJ, Bryan M, Moseley MA, Muoio DM, Andrews NC. Metabolic Catastrophe in Mice Lacking Transferrin Receptor in Muscle. EBioMedicine 2015; 2:1705-17. [PMID: 26870796 PMCID: PMC4740293 DOI: 10.1016/j.ebiom.2015.09.041] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/23/2015] [Accepted: 09/23/2015] [Indexed: 11/29/2022] Open
Abstract
Transferrin receptor (Tfr1) is ubiquitously expressed, but its roles in non-hematopoietic cells are incompletely understood. We used a tissue-specific conditional knockout strategy to ask whether skeletal muscle required Tfr1 for iron uptake. We found that iron assimilation via Tfr1 was critical for skeletal muscle metabolism, and that iron deficiency in muscle led to dramatic changes, not only in muscle, but also in adipose tissue and liver. Inactivation of Tfr1 incapacitated normal energy production in muscle, leading to growth arrest and a muted attempt to switch to fatty acid β oxidation, using up fat stores. Starvation signals stimulated gluconeogenesis in the liver, but amino acid substrates became limiting and hypoglycemia ensued. Surprisingly, the liver was also iron deficient, and production of the iron regulatory hormone hepcidin was depressed. Our observations reveal a complex interaction between iron homeostasis and metabolism that has implications for metabolic and iron disorders. Transferrin receptor 1 is required for iron assimilation by skeletal muscle Selective inactivation of transferrin receptor 1 in muscle causes severe, systemic metabolic derangement Isolated muscle iron deficiency leads to changes in iron homeostasis in the liver
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Affiliation(s)
- Tomasa Barrientos
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Indira Laothamatas
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Timothy R Koves
- Molecular Physiology Institute, Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27704, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Erik J Soderblom
- Duke Proteomics and Metabolomics Shared Resource, Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Miles Bryan
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - M Arthur Moseley
- Duke Proteomics and Metabolomics Shared Resource, Center for Genomic and Computational Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Deborah M Muoio
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA; Molecular Physiology Institute, Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, NC 27704, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA
| | - Nancy C Andrews
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA; Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA
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Ocal O, Pashkov V, Kollipara RK, Zolghadri Y, Cruz VH, Hale MA, Heath BR, Artyukhin AB, Christie AL, Tsoulfas P, Lorens JB, Swift GH, Brekken RA, Wilkie TM. A rapid in vivo screen for pancreatic ductal adenocarcinoma therapeutics. Dis Model Mech 2015; 8:1201-11. [PMID: 26438693 PMCID: PMC4610235 DOI: 10.1242/dmm.020933] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 08/13/2015] [Indexed: 12/11/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer-related deaths in the United States, and is projected to be second by 2025. It has the worst survival rate among all major cancers. Two pressing needs for extending life expectancy of affected individuals are the development of new approaches to identify improved therapeutics, addressed herein, and the identification of early markers. PDA advances through a complex series of intercellular and physiological interactions that drive cancer progression in response to organ stress, organ failure, malnutrition, and infiltrating immune and stromal cells. Candidate drugs identified in organ culture or cell-based screens must be validated in preclinical models such as KIC (p48(Cre);LSL-Kras(G12D);Cdkn2a(f/f)) mice, a genetically engineered model of PDA in which large aggressive tumors develop by 4 weeks of age. We report a rapid, systematic and robust in vivo screen for effective drug combinations to treat Kras-dependent PDA. Kras mutations occur early in tumor progression in over 90% of human PDA cases. Protein kinase and G-protein coupled receptor (GPCR) signaling activates Kras. Regulators of G-protein signaling (RGS) proteins are coincidence detectors that can be induced by multiple inputs to feedback-regulate GPCR signaling. We crossed Rgs16::GFP bacterial artificial chromosome (BAC) transgenic mice with KIC mice and show that the Rgs16::GFP transgene is a Kras(G12D)-dependent marker of all stages of PDA, and increases proportionally to tumor burden in KIC mice. RNA sequencing (RNA-Seq) analysis of cultured primary PDA cells reveals characteristics of embryonic progenitors of pancreatic ducts and endocrine cells, and extraordinarily high expression of the receptor tyrosine kinase Axl, an emerging cancer drug target. In proof-of-principle drug screens, we find that weanling KIC mice with PDA treated for 2 weeks with gemcitabine (with or without Abraxane) plus inhibitors of Axl signaling (warfarin and BGB324) have fewer tumor initiation sites and reduced tumor size compared with the standard-of-care treatment. Rgs16::GFP is therefore an in vivo reporter of PDA progression and sensitivity to new chemotherapeutic drug regimens such as Axl-targeted agents. This screening strategy can potentially be applied to identify improved therapeutics for other cancers.
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Affiliation(s)
- Ozhan Ocal
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Victor Pashkov
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rahul K Kollipara
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yalda Zolghadri
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Victoria H Cruz
- Department of Surgery and Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael A Hale
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Blake R Heath
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Alex B Artyukhin
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Alana L Christie
- Simmons Cancer Center, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, University of Miami School of Medicine, Miami, FL 33136, USA
| | - James B Lorens
- Department of Biomedicine, University of Bergen, N-5009 Bergen, Norway
| | - Galvin H Swift
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rolf A Brekken
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA Department of Surgery and Hamon Center for Therapeutic Oncology Research, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Thomas M Wilkie
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
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Woodard GE, Jardín I, Berna-Erro A, Salido GM, Rosado JA. Regulators of G-protein-signaling proteins: negative modulators of G-protein-coupled receptor signaling. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 317:97-183. [PMID: 26008785 DOI: 10.1016/bs.ircmb.2015.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Regulators of G-protein-signaling (RGS) proteins are a category of intracellular proteins that have an inhibitory effect on the intracellular signaling produced by G-protein-coupled receptors (GPCRs). RGS along with RGS-like proteins switch on through direct contact G-alpha subunits providing a variety of intracellular functions through intracellular signaling. RGS proteins have a common RGS domain that binds to G alpha. RGS proteins accelerate GTPase and thus enhance guanosine triphosphate hydrolysis through the alpha subunit of heterotrimeric G proteins. As a result, they inactivate the G protein and quickly turn off GPCR signaling thus terminating the resulting downstream signals. Activity and subcellular localization of RGS proteins can be changed through covalent molecular changes to the enzyme, differential gene splicing, and processing of the protein. Other roles of RGS proteins have shown them to not be solely committed to being inhibitors but behave more as modulators and integrators of signaling. RGS proteins modulate the duration and kinetics of slow calcium oscillations and rapid phototransduction and ion signaling events. In other cases, RGS proteins integrate G proteins with signaling pathways linked to such diverse cellular responses as cell growth and differentiation, cell motility, and intracellular trafficking. Human and animal studies have revealed that RGS proteins play a vital role in physiology and can be ideal targets for diseases such as those related to addiction where receptor signaling seems continuously switched on.
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Affiliation(s)
- Geoffrey E Woodard
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA; Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Isaac Jardín
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - A Berna-Erro
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Gines M Salido
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Juan A Rosado
- Department of Physiology, University of Extremadura, Caceres, Spain
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Li N, Zhang L, An Y, Zhang L, Song Y, Wang Y, Tang H. Antagonist of prostaglandin E2 receptor 4 induces metabolic alterations in liver of mice. J Proteome Res 2015; 14:1566-73. [PMID: 25669961 DOI: 10.1021/pr501236y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prostaglandin E2 receptor 4 (EP4) is one of the receptors for prostaglandin E2 and plays important roles in various biological functions. EP4 antagonists have been used as anti-inflammatory drugs. To investigate the effects of an EP4 antagonist (L-161982) on the endogenous metabolism in a holistic manner, we employed a mouse model, and obtained metabolic and transcriptomic profiles of multiple biological matrixes, including serum, liver, and urine of mice with and without EP4 antagonist (L-161982) exposure. We found that this EP4 antagonist caused significant changes in fatty acid metabolism, choline metabolism, and nucleotide metabolism. EP4 antagonist exposure also induced oxidative stress to mice. Our research is the first of its kind to report information on the alteration of metabolism associated with an EP4 antagonist. This information could further our understanding of current and new biological functions of EP4.
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Affiliation(s)
- Ning Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Centre for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, University of Chinese Academy of Sciences , Wuhan, 430071, P. R. China
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Larsen MC, Bushkofsky JR, Gorman T, Adhami V, Mukhtar H, Wang S, Reeder SB, Sheibani N, Jefcoate CR. Cytochrome P450 1B1: An unexpected modulator of liver fatty acid homeostasis. Arch Biochem Biophys 2015; 571:21-39. [PMID: 25703193 DOI: 10.1016/j.abb.2015.02.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/23/2015] [Accepted: 02/10/2015] [Indexed: 12/12/2022]
Abstract
Cytochrome P450 1b1 (Cyp1b1) expression is absent in mouse hepatocytes, but present in liver endothelia and activated stellate cells. Increased expression during adipogenesis suggests a role of Cyp1b1 metabolism in fatty acid homeostasis. Wild-type C57BL/6j (WT) and Cyp1b1-null (Cyp1b1-ko) mice were provided low or high fat diets (LFD and HFD, respectively). Cyp1b1-deletion suppressed HFD-induced obesity, improved glucose tolerance and prevented liver steatosis. Suppression of lipid droplets in sinusoidal hepatocytes, concomitant with enhanced glycogen granules, was a consistent feature of Cyp1b1-ko mice. Cyp1b1 deletion altered the in vivo expression of 560 liver genes, including suppression of PPARγ, stearoyl CoA desaturase 1 (Scd1) and many genes stimulated by PPARα, each consistent with this switch in energy storage mechanism. Ligand activation of PPARα in Cyp1b1-ko mice by WY-14643 was, nevertheless, effective. Seventeen gene changes in Cyp1b1-ko mice correspond to mouse transgenic expression that attenuated diet-induced diabetes. The absence of Cyp1b1 in mouse hepatocytes indicates participation in energy homeostasis through extra-hepatocyte signaling. Extensive sexual dimorphism in hepatic gene expression suggests a developmental impact of estrogen metabolism by Cyp1b1. Suppression of Scd1 and increased leptin turnover support enhanced leptin participation from the hypothalamus. Cyp1b1-mediated effects on vascular cells may underlie these changes.
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Affiliation(s)
- Michele Campaigne Larsen
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI 53706, United States
| | - Justin R Bushkofsky
- Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI 53706, United States; Endocrinology and Reproductive Physiology Program, University of Wisconsin, Madison, WI 53706, United States
| | - Tyler Gorman
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI 53706, United States
| | - Vaqar Adhami
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, United States
| | - Hasan Mukhtar
- Department of Dermatology, University of Wisconsin, Madison, WI 53706, United States
| | - Suqing Wang
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI 53706, United States
| | - Scott B Reeder
- Department of Radiology, University of Wisconsin, Madison, WI 53706, United States; Department of Medical Physics, University of Wisconsin, Madison, WI 53706, United States; Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706, United States; Department of Medicine, University of Wisconsin, Madison, WI 53706, United States; Department of Emergency Medicine, University of Wisconsin, Madison, WI 53706, United States
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53706, United States
| | - Colin R Jefcoate
- Department of Cell and Regenerative Biology, University of Wisconsin, Madison, WI 53706, United States; Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI 53706, United States; Endocrinology and Reproductive Physiology Program, University of Wisconsin, Madison, WI 53706, United States.
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Suurväli J, Pahtma M, Saar R, Paalme V, Nutt A, Tiivel T, Saaremäe M, Fitting C, Cavaillon J, Rüütel Boudinot S. RGS16 Restricts the Pro-Inflammatory Response of Monocytes. Scand J Immunol 2014; 81:23-30. [DOI: 10.1111/sji.12250] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 09/26/2014] [Indexed: 02/02/2023]
Affiliation(s)
- J. Suurväli
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - M. Pahtma
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - R. Saar
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - V. Paalme
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - A. Nutt
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - T. Tiivel
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - M. Saaremäe
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
| | - C. Fitting
- Unité Cytokines & Inflammation; Institut Pasteur; Paris France
| | - J.M. Cavaillon
- Unité Cytokines & Inflammation; Institut Pasteur; Paris France
| | - S. Rüütel Boudinot
- Department of Gene Technology; Tallinn University of Technology; Tallinn Estonia
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Abstract
MacroH2A core histone variants have a unique structure that includes a C-terminal nonhistone domain. They are highly conserved in vertebrates and are thought to regulate gene expression. However, the nature of genes regulated by macroH2As and their biological significance remain unclear. Here, we examine macroH2A function in vivo by knocking out both macroH2A1 and macroH2A2 in the mouse. While macroH2As are not required for early development, the absence of macroH2As impairs prenatal and postnatal growth and can significantly reduce reproductive efficiency. The distributions of macroH2A.1- and macroH2A.2-containing nucleosomes show substantial overlap, as do their effects on gene expression. Our studies in fetal and adult liver indicate that macroH2As can exert large positive or negative effects on gene expression, with macroH2A.1 and macroH2A.2 acting synergistically on the expression of some genes and apparently having opposing effects on others. These effects are very specific and in the adult liver preferentially involve genes related to lipid metabolism, including the leptin receptor. MacroH2A-dependent gene regulation changes substantially in postnatal development and can be strongly affected by fasting. We propose that macroH2As produce adaptive changes to gene expression, which in the liver focus on metabolism.
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Regulator of G-protein signaling-5 is a marker of hepatic stellate cells and expression mediates response to liver injury. PLoS One 2014; 9:e108505. [PMID: 25290689 PMCID: PMC4188519 DOI: 10.1371/journal.pone.0108505] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/22/2014] [Indexed: 12/11/2022] Open
Abstract
Liver fibrosis is mediated by hepatic stellate cells (HSCs), which respond to a variety of cytokine and growth factors to moderate the response to injury and create extracellular matrix at the site of injury. G-protein coupled receptor (GPCR)-mediated signaling, via endothelin-1 (ET-1) and angiotensin II (AngII), increases HSC contraction, migration and fibrogenesis. Regulator of G-protein signaling-5 (RGS5), an inhibitor of vasoactive GPCR agonists, functions to control GPCR-mediated contraction and hypertrophy in pericytes and smooth muscle cells (SMCs). Therefore we hypothesized that RGS5 controls GPCR signaling in activated HSCs in the context of liver injury. In this study, we localize RGS5 to the HSCs and demonstrate that Rgs5 expression is regulated during carbon tetrachloride (CCl4)-induced acute and chronic liver injury in Rgs5LacZ/LacZ reporter mice. Furthermore, CCl4 treated RGS5-null mice develop increased hepatocyte damage and fibrosis in response to CCl4 and have increased expression of markers of HSC activation. Knockdown of Rgs5 enhances ET-1-mediated signaling in HSCs in vitro. Taken together, we demonstrate that RGS5 is a critical regulator of GPCR signaling in HSCs and regulates HSC activation and fibrogenesis in liver injury.
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Leung A, Parks BW, Du J, Trac C, Setten R, Chen Y, Brown K, Lusis AJ, Natarajan R, Schones DE. Open chromatin profiling in mice livers reveals unique chromatin variations induced by high fat diet. J Biol Chem 2014; 289:23557-67. [PMID: 25006255 DOI: 10.1074/jbc.m114.581439] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Metabolic diseases result from multiple genetic and environmental factors. We report here that one manner in which environmental factors can contribute to metabolic disease progression is through modification to chromatin. We demonstrate that high fat diet leads to chromatin remodeling in the livers of C57BL/6J mice, as compared with mice fed a control diet, and that these chromatin changes are associated with changes in gene expression. We further show that the regions of greatest variation in chromatin accessibility are targeted by liver transcription factors, including HNF4α, CCAAT/enhancer-binding protein α (CEBP/α), and FOXA1. Repeating the chromatin and gene expression profiling in another mouse strain, DBA/2J, revealed that the regions of greatest chromatin change are largely strain-specific and that integration of chromatin, gene expression, and genetic data can be used to characterize regulatory regions. Our data indicate dramatic changes in the epigenome due to diet and demonstrate strain-specific dynamics in chromatin remodeling.
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Affiliation(s)
- Amy Leung
- From the Departments of Diabetes and
| | - Brian W Parks
- the Department of Medicine, UCLA, Los Angeles, California 90095
| | - Juan Du
- Cancer Biology, Beckman Research Institute and the Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, California 91010 and
| | - Candi Trac
- Cancer Biology, Beckman Research Institute and
| | - Ryan Setten
- the Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, California 91010 and
| | - Yin Chen
- the Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, California 91010 and
| | - Kevin Brown
- Cancer Biology, Beckman Research Institute and
| | - Aldons J Lusis
- the Department of Medicine, UCLA, Los Angeles, California 90095
| | - Rama Natarajan
- From the Departments of Diabetes and the Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, California 91010 and
| | - Dustin E Schones
- Cancer Biology, Beckman Research Institute and the Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, California 91010 and
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Liquid fructose downregulates Sirt1 expression and activity and impairs the oxidation of fatty acids in rat and human liver cells. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:514-24. [DOI: 10.1016/j.bbalip.2014.01.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/13/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023]
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Wu CL, Zhao SP, Yu BL. Microarray analysis provides new insights into the function of apolipoprotein O in HepG2 cell line. Lipids Health Dis 2013; 12:186. [PMID: 24341743 PMCID: PMC3878747 DOI: 10.1186/1476-511x-12-186] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Accepted: 12/13/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Apolipoprotein O (apoO) is a new member of the apolipoprotein family. However, data on its physiological functions are limited and inconsistent. Using a microarray expression analysis, this study explored the function of apoO in liver cells. METHODS HepG2 cells were treated either with oleic acid or tumor necrosis factor-α for 24 h. mRNA and protein expression of apoO were assessed by quantitative real-time PCR (qRT-PCR) and Western blot respectively. An efficient lentiviral siRNA vector targeting the human apoO gene was designed and constructed. The gene expression profile of HepG2 human hepatocellular carcinoma cells transfected with the apoO silencing vector was investigated using a whole-genome oligonucleotide microarray. The expression levels of some altered genes were validated using qRT-PCR. RESULTS ApoO expression in HepG2 cells was dramatically affected by lipid and inflammatory stimuli. A total of 282 differentially expressed genes in apoO-silenced HepG2 cells were identified by microarray analysis. These genes included those participating in fatty acid metabolism, such as ACSL4, RGS16, CROT and CYP4F11, and genes participating in the inflammatory response, such as NFKBIZ, TNFSF15, USP2, IL-17, CCL23, NOTCH2, APH-1B and N2N. The gene Uncoupling protein 2 (UCP2), which is involved in both these metabolic pathways, demonstrated significant changes in mRNA level after transfection. CONCLUSIONS It is likely that apoO participates in fatty acid metabolism and the inflammatory response in HepG2 cells, and UCP2 may act as a mediator between lipid metabolism and inflammation in apoO-silenced HepG2 cells.
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Affiliation(s)
- Chen-Lu Wu
- Department of Cardiology, the Second Xiangya Hospital of Central South University, Middle Ren-Min Road No.139, Changsha, Hunan, 410011, PR China
| | - Shui-Ping Zhao
- Department of Cardiology, the Second Xiangya Hospital of Central South University, Middle Ren-Min Road No.139, Changsha, Hunan, 410011, PR China
| | - Bi-Lian Yu
- Department of Cardiology, the Second Xiangya Hospital of Central South University, Middle Ren-Min Road No.139, Changsha, Hunan, 410011, PR China
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Chen C, Yang B, Zeng Z, Yang H, Liu C, Ren J, Huang L. Genetic dissection of blood lipid traits by integrating genome-wide association study and gene expression profiling in a porcine model. BMC Genomics 2013; 14:848. [PMID: 24299188 PMCID: PMC4046658 DOI: 10.1186/1471-2164-14-848] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 11/19/2013] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Serum concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) are highly heritable traits that are used clinically to evaluate risk for cardiovascular disease in humans. In this study, we applied a genome-wide association study (GWAS) in 1,075 pigs from two populations and gene expression studies on 497 liver samples to dissect the genetic basis of serum lipids in a pig model. RESULTS We totally identified 8, 5, 2 and 3 genomic loci harboring 109 SNPs that were significantly associated with LDL-C, TC, TG and the ratio of HDL-C/LDL-C in two experimental populations, respectively. In the F2 population, the most prominent SNP was identified at the SSC3: 124,769,847 bp where APOB is the well-known candidate gene. However, in the Sutai population, the most number of significant SNPs was identified at SSC2: 64.97-82.22 Mb where LDLR was identified as the candidate gene. Furthermore, we firstly reported 4 novel genomic loci in pigs harboring the LDL-C-associated SNPs. We also observed obvious population heterogeneity in the two tested populations. Through whole-genome gene expression analysis, we detected 718 trait-correlated expressions. Many of these transcripts correspond to candidate genes for blood lipids in humans. The GWAS mapped 120 cis-eQTLs and 523 trans-eQTLs for these transcripts. One gene encoding the transcript gnl|UG|Ssc#S35330332 stands out to be an important candidate gene for LDL-C by an integrative analysis of GWAS, eQTL and trait-associated expression. CONCLUSIONS We identified the genomic regions or candidate genes associated with blood lipids by an integrative analysis of GWAS, QTT and eQTL mapping in pigs. The findings would benefit the further identification of the causative genes for blood lipid traits in both pigs and humans.
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Affiliation(s)
- Congying Chen
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Bin Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Zhijun Zeng
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Hui Yang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Chenlong Liu
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Jun Ren
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
| | - Lusheng Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China
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Kosters A, Sun D, Wu H, Tian F, Felix JC, Li W, Karpen SJ. Sexually dimorphic genome-wide binding of retinoid X receptor alpha (RXRα) determines male-female differences in the expression of hepatic lipid processing genes in mice. PLoS One 2013; 8:e71538. [PMID: 23977068 PMCID: PMC3747242 DOI: 10.1371/journal.pone.0071538] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/28/2013] [Indexed: 02/06/2023] Open
Abstract
Many hepatic functions including lipid metabolism, drug metabolism, and inflammatory responses are regulated in a sex-specific manner due to distinct patterns of hepatic gene expression between males and females. Regulation for the majority of these genes is under control of Nuclear Receptors (NRs). Retinoid X Receptor alpha (RXRα) is an obligate partner for multiple NRs and considered a master regulator of hepatic gene expression, yet the full extent of RXRα chromatin binding in male and female livers is unclear. ChIP-Seq analysis of RXRα and RNA Polymerase2 (Pol2) binding was performed livers of both genders and combined with microarray analysis. Mice were gavage-fed with the RXR ligand LG268 for 5 days (30 mg/kg/day) and RXRα-binding and RNA levels were determined by ChIP-qPCR and qPCR, respectively. ChIP-Seq revealed 47,845 (male) and 46,877 (female) RXRα binding sites (BS), associated with ∼12,700 unique genes in livers of both genders, with 91% shared between sexes. RXRα-binding showed significant enrichment for 2227 and 1498 unique genes in male and female livers, respectively. Correlating RXRα binding strength with Pol2-binding revealed 44 genes being male-dominant and 43 female-dominant, many previously unknown to be sexually-dimorphic. Surprisingly, genes fundamental to lipid metabolism, including Scd1, Fasn, Elovl6, and Pnpla3-implicated in Fatty Liver Disease pathogenesis, were predominant in females. RXRα activation using LG268 confirmed RXRα-binding was 2-3 fold increased in female livers at multiple newly identified RXRα BS including for Pnpla3 and Elovl6, with corresponding ∼10-fold and ∼2-fold increases in Pnpla3 and Elovl6 RNA respectively in LG268-treated female livers, supporting a role for RXRα regulation of sexually-dimorphic responses for these genes. RXRα appears to be one of the most widely distributed transcriptional regulators in mouse liver and is engaged in determining sexually-dimorphic expression of key lipid-processing genes, suggesting novel gender- and gene-specific responses to NR-based treatments for lipid-related liver diseases.
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Affiliation(s)
- Astrid Kosters
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Deqiang Sun
- Division of Biostatistics, Dan L. Duncan Cancer Center, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Hao Wu
- Department of Biostatistics, School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Feng Tian
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Julio C. Felix
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Wei Li
- Division of Biostatistics, Dan L. Duncan Cancer Center, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Saul J. Karpen
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America
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Kursawe R, Caprio S, Giannini C, Narayan D, Lin A, D’Adamo E, Shaw M, Pierpont B, Cushman SW, Shulman GI. Decreased transcription of ChREBP-α/β isoforms in abdominal subcutaneous adipose tissue of obese adolescents with prediabetes or early type 2 diabetes: associations with insulin resistance and hyperglycemia. Diabetes 2013; 62:837-44. [PMID: 23209190 PMCID: PMC3581226 DOI: 10.2337/db12-0889] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Insulin resistance associated with altered fat partitioning in liver and adipose tissues is a prediabetic condition in obese adolescents. We investigated interactions between glucose tolerance, insulin sensitivity, and the expression of lipogenic genes in abdominal subcutaneous adipose and liver tissue in 53 obese adolescents. Based on their 2-h glucose tests they were stratified in the following groups: group 1, 2-h glucose level <120 mg/dL; group 2, 2-h glucose level between 120 and 140 mg/dL; and group 3, 2-h glucose level >140 mg/dL. Liver and adipose tissue insulin sensitivity were greater in group 1 than in group 2 and group 3, and muscle insulin sensitivity progressively decreased from group 1 to group 3. The expression of the carbohydrate-responsive element-binding protein (ChREBP) was decreased in adipose tissue but increased in the liver (eight subjects) in adolescents with impaired glucose tolerance or type 2 diabetes. The expression of adipose ChREBPα and ChREBPβ was inversely related to 2-h glucose level and positively correlated to insulin sensitivity. Improvement of glucose tolerance in four subjects was associated with an increase of ChREBP/GLUT4 expression in the adipose tissue. In conclusion, early in the development of prediabetes/type 2 diabetes in youth, ChREBPβ expression in adipose tissue predicts insulin resistance and, therefore, might play a role in the regulation of glucose tolerance.
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Affiliation(s)
- Romy Kursawe
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
| | - Sonia Caprio
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
- Corresponding author: Sonia Caprio,
| | - Cosimo Giannini
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
| | - Deepak Narayan
- Department of Plastic Surgery, Yale University School of Medicine, New Haven, Connecticut; the
| | - Aiping Lin
- W.M. Keck Foundation Biostatistics Resource, Yale University School of Medicine, New Haven, Connecticut; the
| | - Ebe D’Adamo
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
| | - Melissa Shaw
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
| | - Bridget Pierpont
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; the
| | - Samuel W. Cushman
- Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland; the
| | - Gerald I. Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut; the
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut; and the
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut
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Abstract
Carbohydrate response element binding protein (ChREBP) is a transcription factor activated by glucose that is highly expressed in liver, pancreatic β-cells, brown and white adipose tissues, and muscle. We reported that hepatic suppression of the Chrebp gene improves hepatic steatosis, glucose intolerance, and obesity in genetically obese mice. Moreover, we have studied the role of ChREBP with special reference to feedforward and feedback looping in liver and pancreatic β-cells. Recently, several groups reported that (1) glucose activates ChREBP-α transactivity and in turn ChREBP-α induces ChREBP-β on both transcriptional and translational levels in adipose tissues, and (2) ChREBP regulates glucose transporter type 4 mRNA levels, which may affect glucose uptake in adipose tissues. Moreover, in adipose tissues of obese patients, Chrebpb mRNA levels were much lower than those in lean subjects, while the levels were much higher in liver of obese patients than those in lean subjects. These findings suggest that Chrebpb mRNA levels are different in various tissues and probably in the stages of diabetes mellitus. Herein, we review recent progress in the study of ChREBP with special references to (1) the mechanisms regulating ChREBP transactivity (posttranslational modifications, intramolecular glucose sensing module, feedforward mechanism, and the feedback loop between ChREBP and its target genes), and (2) the role of ChREBP in liver, pancreatic islets and adipose tissues. Understanding the role of ChREBP in each tissue will provide important insight into the pathogenesis of metabolic syndrome.
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Affiliation(s)
- Katsumi Iizuka
- University Hospital Center for Nutritional Support and Infection Control, Gifu University, Gifu 501-1194, Japan.
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47
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Rebollo A, Roglans N, Alegret M, Laguna JC. Way back for fructose and liver metabolism: Bench side to molecular insights. World J Gastroenterol 2012; 18:6552-9. [PMID: 23236229 PMCID: PMC3516224 DOI: 10.3748/wjg.v18.i45.6552] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 09/26/2012] [Accepted: 09/29/2012] [Indexed: 02/06/2023] Open
Abstract
The World Health Organization recommends that the daily intake of added sugars should make up no more than 10% of total energy. The consumption of sugar-sweetened beverages is the main source of added sugars. Fructose, together with glucose, as a component of high fructose corn syrups or as a component of the sucrose molecule, is one of the main sweeteners present in this kind of beverages. Data from prospective and intervention studies clearly point to high fructose consumption, mainly in the form of sweetened beverages, as a risk factor for several metabolic diseases in humans. The incidence of hypertension, nonalcoholic fatty liver disease (NAFLD), dyslipidemia (mainly hypertriglyceridemia), insulin resistance, type 2 diabetes mellitus, obesity, and the cluster of many of these pathologies in the form of metabolic syndrome is higher in human population segments that show high intake of fructose. Adolescent and young adults from low-income families are especially at risk. We recently reviewed evidence from experimental animals and human data that confirms the deleterious effect of fructose on lipid and glucose metabolism. In this present review we update the information generated in the past 2 years about high consumption of fructose-enriched beverages and the occurrence of metabolic disturbances, especially NAFLD, type 2 diabetes mellitus, and metabolic syndrome. We have explored recent data from observational and experimental human studies, as well as experimental data from animal and cell models. Finally, using information generated in our laboratory and others, we provide a view of the molecular mechanisms that may be specifically involved in the development of liver lipid and glucose metabolic alterations after fructose consumption in liquid form.
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48
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Herman MA, Peroni OD, Villoria J, Schön MR, Abumrad NA, Blüher M, Klein S, Kahn BB. A novel ChREBP isoform in adipose tissue regulates systemic glucose metabolism. Nature 2012; 484:333-8. [PMID: 22466288 PMCID: PMC3341994 DOI: 10.1038/nature10986] [Citation(s) in RCA: 463] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 02/23/2012] [Indexed: 12/16/2022]
Abstract
The prevalence of obesity and type 2-diabetes is increasing worldwide and threatens to shorten lifespan. Impaired insulin action in peripheral tissues is a major pathogenic factor. Insulin stimulates glucose uptake in adipose tissue through the Glut4-glucose transporter and alterations in adipose-Glut4 expression or function regulate systemic insulin sensitivity. Downregulation of adipose tissue-Glut4 occurs early in diabetes development. Here we report that adipose tissue-Glut4 regulates the expression of carbohydrate responsive-element binding protein (ChREBP), a transcriptional regulator of lipogenic and glycolytic genes. Furthermore, adipose-ChREBP is a major determinant of adipose tissue fatty acid synthesis and systemic insulin sensitivity. We discovered a new mechanism for glucose-regulation of ChREBP: Glucose-mediated activation of the canonical ChREBP isoform (ChREBPα) induces expression of a novel, potent isoform (ChREBPβ) that is transcribed from an alternative promoter. ChREBPβ expression in human adipose tissue predicts insulin sensitivity indicating that it may be an effective target for treating diabetes.
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Affiliation(s)
- Mark A Herman
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Rudkowska I, Jacques H, Weisnagel SJ, Marette A, Vohl MC. Transcriptomic profiles of skeletal muscle tissue following an euglycemic-hyperinsulinemic clamp in insulin-resistant obese subjects. GENES AND NUTRITION 2012; 8:91-8. [PMID: 22566203 DOI: 10.1007/s12263-012-0298-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 04/21/2012] [Indexed: 12/22/2022]
Abstract
Insulin resistance in skeletal muscle is an early phenomenon in the pathogenesis of type 2 diabetes. Muscle is mainly responsible for insulin-stimulated glucose clearance from the bloodstream. Thus, regulation of gene expression in muscle tissue may be involved in the pathogenesis of insulin resistance. The objective was to investigate gene expression and metabolic pathways alterations in skeletal muscle tissue following an euglycemic-hyperinsulinemic clamp in obese insulin-resistant subjects. We carried out a transcriptome comparison of skeletal muscle tissue before and after a 3-h euglycemic-hyperinsulinemic clamp following 8-week supplementation with n-3 polyunsaturated fatty acid (PUFA) (1.8 g/day) with or without a supplement of fish gelatin (FG) (25 % of daily protein intake) in 16 obese insulin-resistant subjects. Results indicate that approximately 5 % (1932) of expressed transcripts were significantly changed after the clamp in both n-3 PUFA and n-3 PUFA + FG supplementation periods. Of these differentially expressed transcripts, 1394 genes associated with enzymes, transcription and translation regulators, transporters, G protein-coupled receptors, cytokines, and ligand-dependent nuclear receptors were modified. Metabolic pathways that were significantly modified included liver X receptor/retinoid X receptors (RXR) activation, vitamin D receptor/RXR activation, interleukin (IL)-8, acute phase response, IL10, triggering receptor expressed on myeloid cells 1, peroxisome proliferator-activated receptor, G-beta/gamma and hepatocyte growth factor and IL6 signaling. Taken together, results suggest that mainly inflammatory and transcription factors are modified following clamp in obese insulin-resistant subjects. Overall, understanding the changes in metabolic pathways due to insulin may be a potential target for the management of insulin resistance.
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Affiliation(s)
- Iwona Rudkowska
- Institute of Nutraceuticals and Functional Foods (INAF), Laval University, Pavillon des Services, bureau 2729 K, 2440, boulevard Hochelaga, Québec, QC, G1V 0A6, Canada
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