51
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Tagoma A, Alnek K, Kirss A, Uibo R, Haller-Kikkatalo K. MicroRNA profiling of second trimester maternal plasma shows upregulation of miR-195-5p in patients with gestational diabetes. Gene 2018; 672:137-142. [PMID: 29879500 DOI: 10.1016/j.gene.2018.06.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/02/2018] [Accepted: 06/03/2018] [Indexed: 12/11/2022]
Abstract
Gestational diabetes (GDM) is defined as glucose intolerance that presents during pregnancy. It increases the risk of developing diabetes later in life. Recent studies indicate the important role of microRNAs (miRNAs) in the pathogenesis of diabetes, including GDM. However, information on the plasma miRNA profile in GDM patients at the late second trimester, at which time the glucose metabolism disorder manifests, is scarce. This study aimed to determine the plasma miRNA expression profiles of the pregnant women with GDM and compare them to those of pregnant controls using the real-time PCR array method. The study involved 22 single-pregnancy women (mean age ± standard deviation of 29.9 ± 4.5 years old) who underwent a glucose tolerance test between 23 and 31 weeks of gestation. Of them, 13 were diagnosed with GDM. We identified 15 upregulated miRNAs in the GDM patients that were involved in 41 pathways. Among the top 10 associated pathways, fatty acid biosynthesis and fatty acid metabolism were targeted by the most, of the miRNAs investigated, with very low p values (p < 1e-325, false discovery rate corrected). MiR-195-5p, which targeted the highest number of genes important in metabolism, showed the highest fold upregulation. We conclude that increased miRNA expression, especially miR-195-5p, in plasma is characteristic of and causally related to the development of GDM.
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Affiliation(s)
- Aili Tagoma
- Department of Immunology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia.
| | - Kristi Alnek
- Department of Immunology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia
| | - Anne Kirss
- Women's Clinic, Tartu University Hospital, L. Puusepa 8, 51014 Tartu, Estonia
| | - Raivo Uibo
- Department of Immunology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia
| | - Kadri Haller-Kikkatalo
- Department of Immunology, Institute of Biomedicine and Translational Medicine, University of Tartu, Ravila 19, 50411 Tartu, Estonia
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52
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Botta M, Audano M, Sahebkar A, Sirtori CR, Mitro N, Ruscica M. PPAR Agonists and Metabolic Syndrome: An Established Role? Int J Mol Sci 2018; 19:E1197. [PMID: 29662003 PMCID: PMC5979533 DOI: 10.3390/ijms19041197] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 04/10/2018] [Accepted: 04/11/2018] [Indexed: 12/14/2022] Open
Abstract
Therapeutic approaches to metabolic syndrome (MetS) are numerous and may target lipoproteins, blood pressure or anthropometric indices. Peroxisome proliferator-activated receptors (PPARs) are involved in the metabolic regulation of lipid and lipoprotein levels, i.e., triglycerides (TGs), blood glucose, and abdominal adiposity. PPARs may be classified into the α, β/δ and γ subtypes. The PPAR-α agonists, mainly fibrates (including newer molecules such as pemafibrate) and omega-3 fatty acids, are powerful TG-lowering agents. They mainly affect TG catabolism and, particularly with fibrates, raise the levels of high-density lipoprotein cholesterol (HDL-C). PPAR-γ agonists, mainly glitazones, show a smaller activity on TGs but are powerful glucose-lowering agents. Newer PPAR-α/δ agonists, e.g., elafibranor, have been designed to achieve single drugs with TG-lowering and HDL-C-raising effects, in addition to the insulin-sensitizing and antihyperglycemic effects of glitazones. They also hold promise for the treatment of non-alcoholic fatty liver disease (NAFLD) which is closely associated with the MetS. The PPAR system thus offers an important hope in the management of atherogenic dyslipidemias, although concerns regarding potential adverse events such as the rise of plasma creatinine, gallstone formation, drug-drug interactions (i.e., gemfibrozil) and myopathy should also be acknowledged.
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Affiliation(s)
- Margherita Botta
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy.
| | - Matteo Audano
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy.
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran.
- Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran.
- School of Pharmacy, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran.
| | - Cesare R Sirtori
- Centro Dislipidemie, Azienda Socio Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda, 20162 Milan, Italy.
| | - Nico Mitro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy.
| | - Massimiliano Ruscica
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy.
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53
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Moreno-Fernandez ME, Giles DA, Stankiewicz TE, Sheridan R, Karns R, Cappelletti M, Lampe K, Mukherjee R, Sina C, Sallese A, Bridges JP, Hogan SP, Aronow BJ, Hoebe K, Divanovic S. Peroxisomal β-oxidation regulates whole body metabolism, inflammatory vigor, and pathogenesis of nonalcoholic fatty liver disease. JCI Insight 2018; 3:93626. [PMID: 29563328 DOI: 10.1172/jci.insight.93626] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 02/08/2018] [Indexed: 12/14/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD), a metabolic predisposition for development of hepatocellular carcinoma (HCC), represents a disease spectrum ranging from steatosis to steatohepatitis to cirrhosis. Acox1, a rate-limiting enzyme in peroxisomal fatty acid β-oxidation, regulates metabolism, spontaneous hepatic steatosis, and hepatocellular damage over time. However, it is unknown whether Acox1 modulates inflammation relevant to NAFLD pathogenesis or if Acox1-associated metabolic and inflammatory derangements uncover and accelerate potential for NAFLD progression. Here, we show that mice with a point mutation in Acox1 (Acox1Lampe1) exhibited altered cellular metabolism, modified T cell polarization, and exacerbated immune cell inflammatory potential. Further, in context of a brief obesogenic diet stress, NAFLD progression associated with Acox1 mutation resulted in significantly accelerated and exacerbated hepatocellular damage via induction of profound histological changes in hepatocytes, hepatic inflammation, and robust upregulation of gene expression associated with HCC development. Collectively, these data demonstrate that β-oxidation links metabolism and immune responsiveness and that a better understanding of peroxisomal β-oxidation may allow for discovery of mechanisms central for NAFLD progression.
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Affiliation(s)
- Maria E Moreno-Fernandez
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Daniel A Giles
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA.,Immunology Graduate Program, CCHMC, and the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Traci E Stankiewicz
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Rachel Sheridan
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Pathology, CCHMC, Cincinnati, Ohio, USA
| | - Rebekah Karns
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Gastroenterology, Hepatology, and Nutrition, CCHMC, Cincinnati, Ohio, USA
| | - Monica Cappelletti
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Kristin Lampe
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Rajib Mukherjee
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Christian Sina
- Molecular Gastroenterology, University Hospital Schleswig-Holstein, Campus Lübeck, Germany
| | - Anthony Sallese
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Neonatology and Pulmonary Biology
| | - James P Bridges
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Neonatology and Pulmonary Biology
| | - Simon P Hogan
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Allergy and Immunology, and
| | - Bruce J Aronow
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Biomedical Informatics, CCHMC, Cincinnati, Ohio, USA
| | - Kasper Hoebe
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
| | - Senad Divanovic
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio, USA
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54
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Sugihara T, Tanaka S, Braga-Tanaka I, Murano H, Nakamura-Murano M, Komura JI. Screening of biomarkers for liver adenoma in low-dose-rate γ-ray-irradiated mice. Int J Radiat Biol 2018; 94:315-326. [PMID: 29424599 DOI: 10.1080/09553002.2018.1439193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Chronic low-dose-rate (20 mGy/day) γ-irradiation increases the incidence of hepatocellular adenomas (HCA) in female B6C3F1 mice. The purpose of this study is to identify potential serum biomarkers for these HCAs by a new approach. MATERIAL AND METHODS Microarray analysis were performed to compare the gene expression profiles of HCAs from mice exposed to low-dose-rate γ-rays with those of normal livers from non-irradiated mice. From the differentially expressed genes, those for possibly secretory proteins were selected. Then, the levels of the proteins in sera were analysed by ELISA. RESULTS Microarray analysis identified 4181 genes differentially expressed in HCAs (>2.0-fold). From these genes, those for α-fetoprotein (Afp), α-1B-glycoprotein (A1bg) and serine peptidase inhibitor Kazal type-3 (Spink3) were selected as the genes for candidate proteins. ELISA revealed that the levels of Afp and A1bg proteins in sera significantly increased and decreased, respectively, in low-dose-rate irradiated mice with HCAs and also same tendency was observed in human patients with hepatocellular carcinomas. CONCLUSION These results indicate that A1bg could be a new serum biomarker for liver tumor. This new approach of using microarray to select genes for secretory proteins is useful for prediction of novel tumor markers in sera.
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Affiliation(s)
- Takashi Sugihara
- a Department of Radiobiology , Institute for Environmental Sciences , Rokkasho Kamikita , Aomori , Japan
| | - Satoshi Tanaka
- a Department of Radiobiology , Institute for Environmental Sciences , Rokkasho Kamikita , Aomori , Japan
| | - Ignacia Braga-Tanaka
- a Department of Radiobiology , Institute for Environmental Sciences , Rokkasho Kamikita , Aomori , Japan
| | - Hayato Murano
- b Tohoku Environmental Sciences Services Corporation , Rokkasho Kamikita , Aomori , Japan
| | - Masako Nakamura-Murano
- b Tohoku Environmental Sciences Services Corporation , Rokkasho Kamikita , Aomori , Japan
| | - Jun-Ichiro Komura
- a Department of Radiobiology , Institute for Environmental Sciences , Rokkasho Kamikita , Aomori , Japan
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55
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Rutkowski DT. Liver function and dysfunction - a unique window into the physiological reach of ER stress and the unfolded protein response. FEBS J 2018; 286:356-378. [PMID: 29360258 DOI: 10.1111/febs.14389] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/08/2018] [Accepted: 01/17/2018] [Indexed: 02/06/2023]
Abstract
The unfolded protein response (UPR) improves endoplasmic reticulum (ER) protein folding in order to alleviate stress. Yet it is becoming increasingly clear that the UPR regulates processes well beyond those directly involved in protein folding, in some cases by mechanisms that fall outside the realm of canonical UPR signaling. These pathways are highly specific from one cell type to another, implying that ER stress signaling affects each tissue in a unique way. Perhaps nowhere is this more evident than in the liver, which-beyond being a highly secretory tissue-is a key regulator of peripheral metabolism and a uniquely proliferative organ upon damage. The liver provides a powerful model system for exploring how and why the UPR extends its reach into physiological processes that occur outside the ER, and how ER stress contributes to the many systemic diseases that involve liver dysfunction. This review will highlight the ways in which the study of ER stress in the liver has expanded the view of the UPR to a response that is a key guardian of cellular homeostasis outside of just the narrow realm of ER protein folding.
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Affiliation(s)
- D Thomas Rutkowski
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, IA, USA.,Department of Internal Medicine, University of Iowa Carver College of Medicine, IA, USA
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56
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Sheikh AB, Nasrullah A, Haq S, Akhtar A, Ghazanfar H, Nasir A, Afzal RM, Bukhari MM, Chaudhary AY, Naqvi SW. The Interplay of Genetics and Environmental Factors in the Development of Obesity. Cureus 2017; 9:e1435. [PMID: 28924523 PMCID: PMC5587406 DOI: 10.7759/cureus.1435] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Obesity is a major health issue in the developed nations, and it has been increasingly clear that both genetics and environment play an important role in determining if an individual will be obese or not. We reviewed the latest researches which were carried out to identify the obesity susceptible genes and to identify the metabolic pathways having a central role in energy balance. Obesity is a heritable disorder, and some of the many obesity susceptible genes are fat mass and obesity (FTO), leptin, and Melanocortin-4 receptor (MC4R). Glucose metabolism is the central pathway for fatty acid synthesis, de novo generating the major substrate acetyl-CoA. Further knowledge of these genes and their complex interaction with the environment will help devise individual, family and community-based preventive lifestyle interventions as well as nutritional and medical therapies.
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Affiliation(s)
| | - Adeel Nasrullah
- Department of Internal Medicine, Shifa International Hospital
| | - Shujaul Haq
- Department of Internal Medicine, Shifa International Hospital
| | - Aisha Akhtar
- Surgery, Texas Tech Health Sciences Center Lubbock
| | | | - Amara Nasir
- Shifa College of Medicine, Shifa International Hospital
| | - Rao M Afzal
- Internal Medicine, Shifa College Of Medicine
| | | | | | - Syed W Naqvi
- Shifa College of Medicine, Shifa International Hospital
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57
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Wu H, Zhang T, Pan F, Steer CJ, Li Z, Chen X, Song G. MicroRNA-206 prevents hepatosteatosis and hyperglycemia by facilitating insulin signaling and impairing lipogenesis. J Hepatol 2017; 66:816-824. [PMID: 28025059 PMCID: PMC5568011 DOI: 10.1016/j.jhep.2016.12.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 11/23/2016] [Accepted: 12/15/2016] [Indexed: 01/08/2023]
Abstract
BACKGROUND & AIMS The paradox of selective hepatic insulin resistance, wherein the insulin-resistant liver fails to suppress glucose production but continues to produce lipids, has been central to the pathophysiology of hepatosteatosis and hyperglycemia. Our study was designed to investigate the mechanism(s) by which microRNA-206 alleviates the pathogenesis of hepatosteatosis and hyperglycemia. METHODS Dietary obese mice induced by a high fat diet were used to study the role of microRNA-206 in the pathogenesis of hepatosteatosis and hyperglycemia. A mini-circle vector was used to deliver microRNA-206 into the livers of mice. RESULTS Lipid accumulation impaired biogenesis of microRNA-206 in fatty livers of dietary obese mice and human hepatocytes (p<0.01). Delivery of microRNA-206 into the livers of dietary obese mice resulted in the strong therapeutic effects on hepatosteatosis and hyperglycemia. Mechanistically, miR-206 interacted with the 3' untranslated region of PTPN1 (protein tyrosine phosphatase, non-receptor type 1) and induced its degradation. By inhibiting PTPN1 expression, microRNA-206 facilitated insulin signaling by promoting phosphorylation of INSR (insulin receptor) and impaired hepatic lipogenesis by inhibiting Srebp1c transcription. By simultaneously modulating lipogenesis and insulin signaling, microRNA-206 reduced lipid (p=0.006) and glucose (p=0.018) production in human hepatocytes and livers of dietary obese mice (p<0.001 and p<0.01 respectively). Re-introduction of Ptpn1 into livers offset the inhibitory effects of microRNA-206, indicating that PTPN1 mediates the inhibitory effects of microRNA-206 on both hepatosteatosis and hyperglycemia. CONCLUSIONS MicroRNA-206 is a potent inhibitor of lipid and glucose production by simultaneously facilitating insulin signaling and impairing hepatic lipogenesis. Our findings potentially provide a novel therapeutic agent for both hepatosteatosis and hyperglycemia. LAY SUMMARY The epidemic of obesity is causing a sharp rise in the incidence of insulin resistance and its major complications, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). However, there are no effective treatments because the mechanisms underlying both disorders are not well described. We identified microRNA-206 as a novel and effective inhibitor for both glucose and lipid production in liver and potentially provide a unique therapeutic drug for both hepatosteatosis and hyperglycemia.
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Affiliation(s)
- Heng Wu
- Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Tianpeng Zhang
- Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Fei Pan
- Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Clifford J. Steer
- Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA,Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Zhuoyu Li
- Institute of Biotechnology, Shanxi University, Taiyuan City 030006, China
| | - Xin Chen
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA
| | - Guisheng Song
- Department of Medicine, University of Minnesota Medical School, Minneapolis, MN 55455, USA; Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
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58
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Wang Q, Zhao X, Zhang Z, Zhao H, Huang D, Cheng G, Yang Y. Proteomic analysis of physiological function response to hot summer in liver from lactating dairy cows. J Therm Biol 2017; 65:82-87. [PMID: 28343581 DOI: 10.1016/j.jtherbio.2017.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 02/18/2017] [Accepted: 02/21/2017] [Indexed: 11/28/2022]
Abstract
Lactation performance of dairy cattle is susceptible to heat stress. The liver is one of the most crucial organs affected by high temperature in dairy cows. However, the physiological adaption by the liver to hot summer conditions has not been well elucidated in lactating dairy cows. In the present study, proteomic analysis of the liver in dairy cows in spring and hot summer was performed using a label-free method. In total, 127 differentially expressed proteins were identified; most of the upregulated proteins were involved in protein metabolic processes and responses to stimuli, whereas most of the downregulated proteins were related to oxidation-reduction. Pathway analysis indicated that 3 upregulated heat stress proteins (HSP90α, HSP90β, and endoplasmin) were enriched in the NOD-like receptor signaling pathway, whereas several downregulated NADH dehydrogenase proteins were involved in the oxidative phosphorylation pathway. The protein-protein interaction network indicated that several upregulated HSPs (HSP90α, HSP90β, and GRP78) were involved in more interactions than other proteins and were thus considered as central hub nodes. Our findings provide novel insights into the physiological adaption of liver function in lactating dairy cows to natural high temperature.
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Affiliation(s)
- Qiangjun Wang
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China; College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Xiaowei Zhao
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Zijun Zhang
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, China
| | - Huiling Zhao
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Dongwei Huang
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Guanglong Cheng
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Yongxin Yang
- Institute of Animal Science and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei 230031, China.
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59
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Hallowell RW, Collins SL, Craig JM, Zhang Y, Oh M, Illei PB, Chan-Li Y, Vigeland CL, Mitzner W, Scott AL, Powell JD, Horton MR. mTORC2 signalling regulates M2 macrophage differentiation in response to helminth infection and adaptive thermogenesis. Nat Commun 2017; 8:14208. [PMID: 28128208 PMCID: PMC5290163 DOI: 10.1038/ncomms14208] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 12/05/2016] [Indexed: 12/24/2022] Open
Abstract
Alternatively activated macrophages (M2) have an important function in innate immune responses to parasitic helminths, and emerging evidence also indicates these cells are regulators of systemic metabolism. Here we show a critical role for mTORC2 signalling in the generation of M2 macrophages. Abrogation of mTORC2 signalling in macrophages by selective conditional deletion of the adaptor molecule Rictor inhibits the generation of M2 macrophages while leaving the generation of classically activated macrophages (M1) intact. Selective deletion of Rictor in macrophages prevents M2 differentiation and clearance of a parasitic helminth infection in mice, and also abrogates the ability of mice to regulate brown fat and maintain core body temperature. Our findings define a role for mTORC2 in macrophages in integrating signals from the immune microenvironment to promote innate type 2 immunity, and also to integrate systemic metabolic and thermogenic responses.
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Affiliation(s)
- R. W. Hallowell
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brooklyn Avenue, Boston, Massachusetts 02215, USA
| | - S. L. Collins
- Department of Medicine, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - J. M. Craig
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 650 North Wolfe Street, Baltimore, Maryland 21205, USA
| | - Y. Zhang
- Department of Respiratory Diseases, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 1239 Siping Road, Shanghai 200433, China
| | - M. Oh
- Department of Oncology, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - P. B. Illei
- Department of Pathology, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - Y. Chan-Li
- Department of Medicine, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - C. L. Vigeland
- Department of Medicine, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - W. Mitzner
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 650 North Wolfe Street, Baltimore, Maryland 21205, USA
| | - A. L. Scott
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, 650 North Wolfe Street, Baltimore, Maryland 21205, USA
| | - J. D. Powell
- Department of Oncology, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
| | - M. R. Horton
- Department of Medicine, Johns Hopkins University School of Medicine, 735 North Broadway, Baltimore, Maryland 21205, USA
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60
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Zeng J, Deng S, Wang Y, Li P, Tang L, Pang Y. Specific Inhibition of Acyl-CoA Oxidase-1 by an Acetylenic Acid Improves Hepatic Lipid and Reactive Oxygen Species (ROS) Metabolism in Rats Fed a High Fat Diet. J Biol Chem 2017; 292:3800-3809. [PMID: 28077576 DOI: 10.1074/jbc.m116.763532] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 01/05/2017] [Indexed: 01/08/2023] Open
Abstract
A chronic high fat diet results in hepatic mitochondrial dysfunction and induction of peroxisomal fatty acid oxidation (FAO); whether specific inhibition of peroxisomal FAO benefits mitochondrial FAO and reactive oxygen species (ROS) metabolism remains unclear. In this study a specific inhibitor for the rate-limiting enzyme involved in peroxisomal FAO, acyl-CoA oxidase-1 (ACOX1) was developed and used for the investigation of peroxisomal FAO inhibition upon mitochondrial FAO and ROS metabolism. Specific inhibition of ACOX1 by 10,12-tricosadiynoic acid increased hepatic mitochondrial FAO via activation of the SIRT1-AMPK (adenosine 5'-monophosphate-activated protein kinase) pathway and proliferator activator receptor α and reduced hydrogen peroxide accumulation in high fat diet-fed rats, which significantly decreased hepatic lipid and ROS contents, reduced body weight gain, and decreased serum triglyceride and insulin levels. Inhibition of ACOX1 is a novel and effective approach for the treatment of high fat diet- or obesity-induced metabolic diseases by improving mitochondrial lipid and ROS metabolism.
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Affiliation(s)
- Jia Zeng
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Senwen Deng
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Yiping Wang
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Ping Li
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Lian Tang
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
| | - Yefeng Pang
- From the School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
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61
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Ulloa-Martínez M, Burguete-García AI, Murugesan S, Hoyo-Vadillo C, Cruz-Lopez M, García-Mena J. Expression of candidate genes associated with obesity in peripheral white blood cells of Mexican children. Arch Med Sci 2016; 12:968-976. [PMID: 27695486 PMCID: PMC5016575 DOI: 10.5114/aoms.2016.58126] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/04/2015] [Indexed: 01/16/2023] Open
Abstract
INTRODUCTION Obesity is a chronic, complex, and multifactorial disease, characterized by excess body fat. Diverse studies of the human genome have led to the identification of susceptibility genes that contribute to obesity. However, relatively few studies have addressed specifically the association between the level of expression of these genes and obesity. MATERIAL AND METHODS We studied 160 healthy and obese unrelated Mexican children aged 6 to 14 years. We measured the transcriptional expression of 20 genes associated with obesity, in addition to the biochemical parameters, in peripheral white blood cells. The detection of mRNA levels was performed using the OpenArray Real-Time PCR System (Applied Biosystems). RESULTS Obese children exhibited higher values of fasting glucose (p = 0.034), fasting insulin (p = 0.004), low-density lipoprotein (p = 0.006), triglycerides (p < 0.001), systolic blood pressure and diastolic blood pressure (p < 0.001), and lower values of high-density lipoprotein (p < 0.001) compared to lean children. Analysis of transcriptional expression data showed a difference for ADRB1 (p = 0.0297), ADIPOR1 (p = 0.0317), GHRL (p = 0.0060) and FTO (p = 0.0348) genes. CONCLUSIONS Our results suggest that changes in the expression level of the studied genes are involved in biological processes implicated in the development of childhood obesity. Our study contributes new perspectives for a better understanding of biological processes involved in obesity. The protocol was approved by the National Committee and Ethical Committee Board from the Mexican Social Security Institute (IMSS) (IMSS FIS/IMSS/PRIO/10/011).
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Affiliation(s)
- Marcela Ulloa-Martínez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, México
| | - Ana I. Burguete-García
- Dirección de Infecciones Crónicas y Cáncer, CISEI, Instituto Nacional de Salud Pública, México, México
| | - Selvasankar Murugesan
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, México
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, México, México
| | - Carlos Hoyo-Vadillo
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del IPN, México, México
| | - Miguel Cruz-Lopez
- Unidad Unidad de Investigación Médica en Bioquímica, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, México, México
| | - Jaime García-Mena
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, México
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Hinds TD, Adeosun SO, Alamodi AA, Stec DE. Does bilirubin prevent hepatic steatosis through activation of the PPARα nuclear receptor? Med Hypotheses 2016; 95:54-57. [PMID: 27692168 PMCID: PMC5433619 DOI: 10.1016/j.mehy.2016.08.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/05/2016] [Accepted: 08/31/2016] [Indexed: 12/15/2022]
Abstract
Several large population studies have demonstrated a negative correlation between serum bilirubin levels and the development of obesity, hepatic steatosis, and cardiovascular disease. Despite the strong correlative data demonstrating the protective role of bilirubin, the mechanism by which bilirubin can protect against these pathologies remains unknown. Bilirubin has long been known as a powerful antioxidant and also has anti-inflammatory actions, each of which may contribute to the protection afforded by increased levels. We have recently described a novel function of bilirubin as a ligand for the peroxisome proliferator-activated receptor-alpha (PPARα), which we show specifically binds to the nuclear receptor. Bilirubin may function as a selective PPAR modulator (SPPARM) to control lipid accumulation and blood glucose. However, it is not known to what degree bilirubin activation of PPARα is responsible for the protection afforded to reduce hepatic steatosis. We hypothesize that bilirubin, acting as a novel SPPARM, increases hepatic fatty acid metabolism through a PPARα-dependent mechanism which reduces hepatic lipid accumulation and protects against hepatic steatosis and non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Terry D Hinds
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3000 Arlington Avenue, Toledo, OH 43614, USA
| | - Samuel O Adeosun
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA
| | - Abdulhadi A Alamodi
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA
| | - David E Stec
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216, USA.
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63
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Du C, Wu M, Liu H, Ren Y, Du Y, Wu H, Wei J, Liu C, Yao F, Wang H, Zhu Y, Duan H, Shi Y. Thioredoxin-interacting protein regulates lipid metabolism via Akt/mTOR pathway in diabetic kidney disease. Int J Biochem Cell Biol 2016; 79:1-13. [PMID: 27497988 DOI: 10.1016/j.biocel.2016.08.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/30/2016] [Accepted: 08/03/2016] [Indexed: 12/12/2022]
Abstract
Abnormal lipid metabolism contributes to the renal lipid accumulation, which is associated with diabetic kidney disease, but its precise mechanism remains unclear. The growing evidence demonstrates that thioredoxin-interacting protein is involved in regulating cellular glucose and lipid metabolism. Here, we investigated the effects of thioredoxin-interacting protein on lipid accumulation in diabetic kidney disease. In contrast to the diabetic wild-type mice, the physical and biochemical parameters were improved in the diabetic thioredoxin-interacting protein knockout mice. The increased renal lipid accumulation, expression of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element binding protein-1, and phosphorylated Akt and mTOR associated with diabetes in wild-type mice was attenuated in diabetic thioredoxin-interacting protein knockout mice. Furthermore, thioredoxin-interacting protein knockout significantly increased the expression of peroxisome proliferator-activated receptor-α, acyl-coenzyme A oxidase 1 and carnitine palmitoyltransferaser 1 in diabetic kidneys. In vitro experiments, using HK-2 cells, revealed that knockdown of thioredoxin-interacting protein inhibited high glucose-mediated lipid accumulation, expression of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element binding protein-1, as well as activation of Akt and mTOR. Moreover, knockdown of thioredoxin-interacting protein reversed high glucose-induced reduction of peroxisome proliferator-activated receptor-α, acyl-coenzyme A oxidase 1 and carnitine palmitoyltransferaser 1 expression in HK-2 cells. Importantly, blockade of Akt/mTOR signaling pathway with LY294002, a specific PI3K inhibitor, replicated these effects of thioredoxin-interacting protein silencing. Taken together, these data suggest that thioredoxin-interacting protein deficiency alleviates diabetic renal lipid accumulation through regulation of Akt/mTOR pathway, thioredoxin-interacting protein may be a potential therapeutic target for diabetic kidney disease.
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Affiliation(s)
- Chunyang Du
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China.
| | - Ming Wu
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Huan Liu
- BGI-Shenzhen, Shenzhen, Guangdong, China
| | - Yunzhuo Ren
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China.
| | - Yunxia Du
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Haijiang Wu
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Jinying Wei
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Chuxin Liu
- BGI-Shenzhen, Shenzhen, Guangdong, China
| | - Fang Yao
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Hui Wang
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China
| | - Yan Zhu
- Laboratorical Center for Electron Microscopy, Hebei Medical University, Shijiazhuang, China
| | - Huijun Duan
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China.
| | - Yonghong Shi
- Department of Pathology, Hebei Medical University, Shijiazhuang, China; Hebei Key Laboratory of Kidney Diseases, Shijiazhuang, China.
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SIK2 regulates fasting-induced PPARα activity and ketogenesis through p300. Sci Rep 2016; 6:23317. [PMID: 26983400 PMCID: PMC4794759 DOI: 10.1038/srep23317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/03/2016] [Indexed: 11/19/2022] Open
Abstract
Fatty acid oxidation and subsequent ketogenesis is one of the major mechanisms to maintain hepatic lipid homeostasis under fasting conditions. Fasting hormone glucagon has been shown to stimulate ketone body production through activation of PPARα; however, the signal pathway linking glucagon to PPARα is largely undiscovered. Here we report that a SIK2-p300-PPARα cascade mediates glucagon’s effect on ketogenesis. p300 interacts with PPARα through a conserved LXXLL motif and enhances its transcriptional activity. SIK2 disrupts p300-PPARα interaction by direct phosphorylation of p300 at Ser89, which in turn decreases PPARα-mediated ketogenic gene expression. Moreover, SIK2 phosphorylation defective p300 (p300 S89A) shows increased interaction with PPARα and abolishes suppression of SIK2 on PPARα-mediated ketogenic gene expression in liver. Taken together, our results unveil the signal pathway that mediates fasting induced ketogenesis to maintain hepatic lipid homeostasis.
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Chen WM, Shaw LH, Chang PJ, Tung SY, Chang TS, Shen CH, Hsieh YY, Wei KL. Hepatoprotective effect of resveratrol against ethanol-induced oxidative stress through induction of superoxide dismutase in vivo and in vitro. Exp Ther Med 2016; 11:1231-1238. [PMID: 27073428 PMCID: PMC4812565 DOI: 10.3892/etm.2016.3077] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/01/2015] [Indexed: 12/14/2022] Open
Abstract
The present study aimed to investigate the hepatoprotective effect of resveratrol (RSV) against ethanol-induced oxidative stress in vivo, and investigate the underlying mechanisms by which RSV exerts its anti-oxidative effects on hepatic cells. C57BL/6J mice were divided into four groups: Untreated control, ethanol-treated, RSV-treated, and ethanol + RSV-treated. The plasma lipid profile, hepatic lipid accumulation and antioxidative enzyme activities were analyzed. HepG2 cells were used as a cellular model to analyze the effects of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and peroxisome proliferator-activated receptors (PPARs) in the RSV-mediated protection of ethanol-induced oxidative stress. In C57BL/6J mice, ethanol caused a significant increase in plasma triglyceride levels and hepatic lipid accumulation (P<0.05), whereas RSV notably increased SOD activity. In HepG2 cells, SOD activity was enhanced in the RSV-treated HepG2 cells, whereas the activity of CAT and GPx was not affected. Western blot and quantitative polymerase chain reaction analyses demonstrated that RSV significantly increased SOD protein and mRNA expression levels (P<0.05). Using a transient transfection assay, PPARγ was observed to participate in the regulation of SOD gene expression in RSV-administered HepG2 cells. To conclude, the results from the present study suggest that RSV may contribute towards the protection of hepatic cells from ethanol-induced oxidative stress via the induction of SOD activity and gene expression.
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Affiliation(s)
- Wei-Ming Chen
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C.; College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Lee-Hsin Shaw
- Institute of Traditional Medicine, National Yang-Ming University, Taipei 11221, Taiwan, R.O.C
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Shui-Yi Tung
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Te-Sheng Chang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Chein-Heng Shen
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Yung-Yu Hsieh
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
| | - Kuo-Liang Wei
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Chang Gung Memorial Hospital, Puzi, Chiayi 61363, Taiwan, R.O.C.; College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, R.O.C
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Jiang Y, Chen L, Wang H, Narisi B, Chen B. Li-Gan-Shi-Liu-Ba-Wei-San improves non-alcoholic fatty liver disease through enhancing lipid oxidation and alleviating oxidation stress. JOURNAL OF ETHNOPHARMACOLOGY 2015; 176:499-507. [PMID: 26571089 DOI: 10.1016/j.jep.2015.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 09/18/2015] [Accepted: 11/06/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Mongolian medicine is an important constituent of traditional Chinese medicine. Its representative prescription, Li-Gan-Shi-Liu-Ba-Wei-San (LGSLBWS), is widely used for long-term treatment of chronic liver disease and nonalcoholic fatty liver disease (NAFLD). AIM OF THE STUDY This study explored the effects and mechanism of LGSLBWS on NAFLD. MATERIALS AND METHODS NAFLD rat model was established with high-fat diet. The effects of LGSLBWS on lipid metabolism, liver function, and hepatic morphology were observed in NAFLD rats. Superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver, as well as the expression levels of peroxisome proliferator-activated receptor (PPAR)α, PPARβ, inhibitor of nuclear factor κB α(IκBα), and inducible nitric oxide synthase (iNOS) were all detected. Finally, the effects of LGSLBWS on fatty acid oxidation, PPARα, PPARβ, IκBα, and iNOS were determined in HepG2 cells. RESULTS LGSLBWS significantly reduced the fat deposition in the liver and the serum aspartate aminotransferase levels in NAFLD rats. Serum triglyceride and free fatty acid levels were reduced by LGSLBWS. Total cholesterol and triglyceride contents in the liver were also downregulated. SOD and MDA levels were increased and decreased by LGSLBWS, respectively. LGSLBWS can significantly promote fatty acid oxidation of HepG2 cells. Upregulation of PPARα, PPARβ, and IκBα and downregulation of iNOS by LGSLBWS were both observed in the NAFLD model and HepG2 cells. CONCLUSIONS LGSLBWS can significantly improve NAFLD by enhancing fatty acid oxidation and alleviating oxidative stress.
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Affiliation(s)
- Youzhao Jiang
- Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Liu Chen
- Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Hui Wang
- Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Bao Narisi
- Department of Basic Theory of Mongolian medicine, Institute of Mongolian Medicine, Inner Mongolia Medical University, Hohhot 010110, China
| | - Bing Chen
- Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
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Liu H, Wu C, Wang S, Gao S, Liu J, Dong Z, Zhang B, Liu M, Sun X, Guo P. Extracts and lignans of Schisandra chinensis fruit alter lipid and glucose metabolism in vivo and in vitro. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.09.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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68
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Gao Q, Jia Y, Yang G, Zhang X, Boddu PC, Petersen B, Narsingam S, Zhu YJ, Thimmapaya B, Kanwar YS, Reddy JK. PPARα-Deficient ob/ob Obese Mice Become More Obese and Manifest Severe Hepatic Steatosis Due to Decreased Fatty Acid Oxidation. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1396-408. [PMID: 25773177 DOI: 10.1016/j.ajpath.2015.01.018] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 01/05/2015] [Accepted: 01/12/2015] [Indexed: 02/06/2023]
Abstract
Obesity poses an increased risk of developing metabolic syndrome and closely associated nonalcoholic fatty liver disease, including liver cancer. Satiety hormone leptin-deficient (ob/ob) mice, considered paradigmatic of nutritional obesity, develop hepatic steatosis but are less prone to developing liver tumors. Sustained activation of peroxisome proliferator-activated receptor α (PPARα) in ob/ob mouse liver increases fatty acid oxidation (FAO), which contributes to attenuation of obesity but enhances liver cancer risk. To further evaluate the role of PPARα-regulated hepatic FAO and energy burning in the progression of fatty liver disease, we generated PPARα-deficient ob/ob (PPARα(Δ)ob/ob) mice. These mice become strikingly more obese compared to ob/ob littermates, with increased white and brown adipose tissue content and severe hepatic steatosis. Hepatic steatosis becomes more severe in fasted PPARα(Δ)ob/ob mice as they fail to up-regulate FAO systems. PPARα(Δ)ob/ob mice also do not respond to peroxisome proliferative and mitogenic effects of PPARα agonist Wy-14,643. Although PPARα(Δ)ob/ob mice are severely obese, there was no significant increase in liver tumor incidence, even when maintained on a diet containing Wy-14,643. We conclude that sustained PPARα activation-related increase in FAO in fatty livers of obese ob/ob mice increases liver cancer risk, whereas deletion of PPARα in ob/ob mice aggravates obesity and hepatic steatosis. However, it does not lead to liver tumor development because of reduction in FAO and energy burning.
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Affiliation(s)
- Qian Gao
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Shaanxi, China
| | - Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Gongshe Yang
- Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Shaanxi, China
| | - Xiaohong Zhang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Prajwal C Boddu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Bryon Petersen
- Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida
| | - Saiprasad Narsingam
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yi-Jun Zhu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yashpal S Kanwar
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Janardan K Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
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Abstract
The liver is an essential metabolic organ, and its metabolic function is controlled by insulin and other metabolic hormones. Glucose is converted into pyruvate through glycolysis in the cytoplasm, and pyruvate is subsequently oxidized in the mitochondria to generate ATP through the TCA cycle and oxidative phosphorylation. In the fed state, glycolytic products are used to synthesize fatty acids through de novo lipogenesis. Long-chain fatty acids are incorporated into triacylglycerol, phospholipids, and/or cholesterol esters in hepatocytes. These complex lipids are stored in lipid droplets and membrane structures, or secreted into the circulation as very low-density lipoprotein particles. In the fasted state, the liver secretes glucose through both glycogenolysis and gluconeogenesis. During pronged fasting, hepatic gluconeogenesis is the primary source for endogenous glucose production. Fasting also promotes lipolysis in adipose tissue, resulting in release of nonesterified fatty acids which are converted into ketone bodies in hepatic mitochondria though β-oxidation and ketogenesis. Ketone bodies provide a metabolic fuel for extrahepatic tissues. Liver energy metabolism is tightly regulated by neuronal and hormonal signals. The sympathetic system stimulates, whereas the parasympathetic system suppresses, hepatic gluconeogenesis. Insulin stimulates glycolysis and lipogenesis but suppresses gluconeogenesis, and glucagon counteracts insulin action. Numerous transcription factors and coactivators, including CREB, FOXO1, ChREBP, SREBP, PGC-1α, and CRTC2, control the expression of the enzymes which catalyze key steps of metabolic pathways, thus controlling liver energy metabolism. Aberrant energy metabolism in the liver promotes insulin resistance, diabetes, and nonalcoholic fatty liver diseases.
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Affiliation(s)
- Liangyou Rui
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan
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Parihar P, Solanki I, Mansuri ML, Parihar MS. Mitochondrial sirtuins: emerging roles in metabolic regulations, energy homeostasis and diseases. Exp Gerontol 2014; 61:130-41. [PMID: 25482473 DOI: 10.1016/j.exger.2014.12.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/19/2014] [Accepted: 12/03/2014] [Indexed: 12/18/2022]
Abstract
The energy production and metabolic homeostasis are well-orchestrated networks of carbohydrate, lipid and protein metabolism. These metabolic pathways are integrated by a key cytoplasmic organelle, the mitochondria, leading to production of many metabolic intermediates and harvest cellular energy in the form of ATP. Sirtuins are a highly conserved family of proteins that mediate cellular physiology and energy demands in response to metabolic inputs. Mitochondria inhabit three main types of sirtuins classified as Sirt3, Sirt4 and Sirt5. These sirtuins regulate mitochondrial metabolic functions mainly through controlling post-translational modifications of mitochondrial protein. However, the biological mechanism involved in controlling mitochondrial metabolic functions is not well understood at this stage. In this review the current knowledge on how mitochondrial sirtuins govern mitochondrial functions including energy production, metabolism, biogenesis and their involvement in different metabolic pathways are discussed. The identifications of potential pharmacological targets of sirtuins in the mitochondria and the bioactive compounds that target mitochondrial sirtuins will increase our understanding on regulation of mitochondrial metabolism in normal and disease state.
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Affiliation(s)
- Priyanka Parihar
- School of Studies in Zoology & Biotechnology, Vikram University, Ujjain, MP, India
| | - Isha Solanki
- School of Studies in Zoology & Biotechnology, Vikram University, Ujjain, MP, India
| | | | - Mordhwaj S Parihar
- School of Studies in Zoology & Biotechnology, Vikram University, Ujjain, MP, India.
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71
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Prabhakar P, Reeta KH, Maulik SK, Dinda AK, Gupta YK. Protective effect of thymoquinone against high-fructose diet-induced metabolic syndrome in rats. Eur J Nutr 2014; 54:1117-27. [DOI: 10.1007/s00394-014-0788-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 10/14/2014] [Indexed: 01/18/2023]
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Ringseis R, Gessner DK, Eder K. Molecular insights into the mechanisms of liver-associated diseases in early-lactating dairy cows: hypothetical role of endoplasmic reticulum stress. J Anim Physiol Anim Nutr (Berl) 2014; 99:626-45. [DOI: 10.1111/jpn.12263] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 09/10/2014] [Indexed: 12/14/2022]
Affiliation(s)
- R. Ringseis
- Institute of Animal Nutrition and Nutrition Physiology; Justus-Liebig-University Giessen; Giessen Germany
| | - D. K. Gessner
- Institute of Animal Nutrition and Nutrition Physiology; Justus-Liebig-University Giessen; Giessen Germany
| | - K. Eder
- Institute of Animal Nutrition and Nutrition Physiology; Justus-Liebig-University Giessen; Giessen Germany
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Wang XG, Han M, Zhang LD, Wu GX, Ding H, Zhang B, Huang LH. Regulatory effect of hydrogen sulfide on β oxidation in fatty liver in rats. Shijie Huaren Xiaohua Zazhi 2014; 22:3791-3795. [DOI: 10.11569/wcjd.v22.i25.3791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To observe the regulatory effect of hydrogen sulfide on β oxidation in fatty liver in rats.
METHODS: Eighteen male SD rats were randomly divided into a normal control group, a high-fat diet group and a high-fat diet + NaHS group. High-fat diet was ordinary diet supplemented with 2% cholesterol and 18% lard. The high-fat diet + NaHS group was given a high-fat diet and intraperitoneal injection of 400 mmol/L sodium hydrosulfide solution (5 mL/kg). Eight weeks after treatment, the animals were killed. The content of ketones and enoyl-CoA hydratase activity in liver homogenates were measured, and pathological changes in the liver were observed.
RESULTS: After 8 wk of treatment, fatty liver was successfully induced. Application of sodium hydrosulfide reduced fatty liver significantly. Intrahepatic triglyceride and cholesterol significantly increased in the high-fat diet group compared with the normal control group (3.87 mmol/L ± 2.63 mmol/L vs 1.18 mmol/L ± 0.85 mmol/L, 5.00 mmol/L ± 1.01 mmol/L vs 2.61 mmol/L ± 0.33 mmol/L), while treatment with sodium hydrosulfide significantly reduced hepatic lipid composition (2.28 mmol/L ± 0.51 mmol/L vs 3.87 ± 2.63 mmol/L, 4.50 mmol/L ± 1.25 mmol/L vs 5.00 mmol/L ± 1.01 mmol/L). Compared with the normal control group, hydrogen sulfide content in the high-fat diet group was significantly reduced (14.00 µmol/L ± 6.21 µmol/L vs 20.20 µmol/L ± 11.90 µmol/L); however, application of sodium hydrosulfide significantly increased hydrogen sulfide content (48.20 µmol/L ± 8.50 µmol/L vs 14.00 µmol/L ± 6.21 µmol/L). Compared with the control animals, the liver enoyl-CoA activity was significantly reduced in the high-fat diet group (25.0 µmol/min ± 7.7 µmol/min vs 12.6 µmol/min ± 3.1 µmol/min), by up to 50%, while sodium hydrosulfide significantly increased enoyl-CoA activity (19.9 µmol/min ± 6.0 µmol/min vs 12.6 µmol/min ± 3.1 µmol/min), by 60%. Hydrogen sulfide content was negatively correlated with TG and TC in the high-fat diet group (r = -0.621, -0.432, P = 0.01036, 0.04497), but positively correlated with enoyl-CoA hydratase activity (r = 0.513, P = 0.00833).
CONCLUSION: Hydrogen sulfide promotes β oxidation and reduces fat accumulation in fatty liver in rats.
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Moon J, Do HJ, Cho Y, Shin MJ. Arginase inhibition ameliorates hepatic metabolic abnormalities in obese mice. PLoS One 2014; 9:e103048. [PMID: 25057910 PMCID: PMC4109998 DOI: 10.1371/journal.pone.0103048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 06/26/2014] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVES We examined whether arginase inhibition influences hepatic metabolic pathways and whole body adiposity in diet-induced obesity. METHODS AND RESULTS After obesity induction by a high fat diet (HFD), mice were fed either the HFD or the HFD with an arginase inhibitor, Nω-hydroxy-nor-L-arginine (nor-NOHA). Nor-NOHA significantly prevented HFD-induced increases in body, liver, and visceral fat tissue weight, and ameliorated abnormal lipid profiles. Furthermore, nor-NOHA treatment reduced lipid accumulation in oleic acid-induced hepatic steatosis in vitro. Arginase inhibition increased hepatic nitric oxide (NO) in HFD-fed mice and HepG2 cells, and reversed the elevated mRNA expression of hepatic genes in lipid metabolism. Expression of phosphorylated 5' AMPK-activated protein kinase α was increased by arginase inhibition in the mouse livers and HepG2 cells. CONCLUSIONS Arginase inhibition ameliorated obesity-induced hepatic lipid abnormalities and whole body adiposity, possibly as a result of increased hepatic NO production and subsequent activation of metabolic pathways involved in hepatic triglyceride metabolism and mitochondrial function.
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Affiliation(s)
- Jiyoung Moon
- Department of Food and Nutrition, Korea University, Seoul, Republic of Korea
- Department of Public Health Sciences, Graduate School, Korea University, Seoul, Republic of Korea
| | - Hyun Ju Do
- Department of Food and Nutrition, Korea University, Seoul, Republic of Korea
| | - Yoonsu Cho
- Department of Food and Nutrition, Korea University, Seoul, Republic of Korea
- Department of Public Health Sciences, Graduate School, Korea University, Seoul, Republic of Korea
| | - Min-Jeong Shin
- Department of Food and Nutrition, Korea University, Seoul, Republic of Korea
- Department of Public Health Sciences, Graduate School, Korea University, Seoul, Republic of Korea
- Korea University Guro Hospital, Korea University, Seoul, Republic of Korea
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Ruscogenin ameliorates experimental nonalcoholic steatohepatitis via suppressing lipogenesis and inflammatory pathway. BIOMED RESEARCH INTERNATIONAL 2014; 2014:652680. [PMID: 25136608 PMCID: PMC4127260 DOI: 10.1155/2014/652680] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 06/11/2014] [Indexed: 11/18/2022]
Abstract
The aim of the study was to investigate the protective effects of ruscogenin, a major steroid sapogenin in Ophiopogon japonicus, on experimental models of nonalcoholic steatohepatitis. HepG2 cells were exposed to 300 μmol/l palmitic acid (PA) for 24 h with the preincubation of ruscogenin for another 24 h. Ruscogenin (10.0 μmol/l) had inhibitory effects on PA-induced triglyceride accumulation and inflammatory markers in HepG2 cells. Male golden hamsters were randomly divided into five groups fed a normal diet, a high-fat diet (HFD), or a HFD supplemented with ruscogenin (0.3, 1.0, or 3.0 mg/kg/day) by gavage once daily for 8 weeks. Ruscogenin alleviated dyslipidemia, liver steatosis, and necroinflammation and reversed plasma markers of metabolic syndrome in HFD-fed hamsters. Hepatic mRNA levels involved in fatty acid oxidation were increased in ruscogenin-treated HFD-fed hamsters. Conversely, ruscogenin decreased expression of genes involved in hepatic lipogenesis. Gene expression of inflammatory cytokines, chemoattractive mediator, nuclear transcription factor-(NF-) κB, and α-smooth muscle actin were increased in the HFD group, which were attenuated by ruscogenin. Ruscogenin may attenuate HFD-induced steatohepatitis through downregulation of NF-κB-mediated inflammatory responses, reducing hepatic lipogenic gene expression, and upregulating proteins in β-oxidation pathway.
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Misra P, Reddy JK. Peroxisome proliferator-activated receptor-α activation and excess energy burning in hepatocarcinogenesis. Biochimie 2014; 98:63-74. [DOI: 10.1016/j.biochi.2013.11.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 11/14/2013] [Indexed: 01/23/2023]
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Ezrokhi M, Luo S, Trubitsyna Y, Cincotta AH. Neuroendocrine and metabolic components of dopamine agonist amelioration of metabolic syndrome in SHR rats. Diabetol Metab Syndr 2014; 6:104. [PMID: 25937836 PMCID: PMC4416398 DOI: 10.1186/1758-5996-6-104] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/16/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The hypertensive, pro-inflammatory, obese state is strongly coupled to peripheral and hepatic insulin resistance (in composite termed metabolic syndrome [MS]). Hepatic pro-inflammatory pathways have been demonstrated to initiate or exacerbate hepatic insulin resistance and contribute to fatty liver, a correlate of MS. Previous studies in seasonally obese animals have implicated an important role for circadian phase-dependent increases in hypothalamic dopaminergic tone in the maintenance of the lean, insulin sensitive condition. However, mechanisms driving this dopaminergic effect have not been fully delineated and the impact of such dopaminergic function upon the above mentioned parameters of MS, particularly upon key intra-hepatic regulators of liver inflammation and lipid and glucose metabolism have never been investigated. OBJECTIVE This study therefore investigated the effects of timed daily administration of bromocriptine, a potent dopamine D2 receptor agonist, on a) ventromedial hypothalamic catecholamine activity, b) MS and c) hepatic protein levels of key regulators of liver inflammation and glucose and lipid metabolism in a non-seasonal model of MS - the hypertensive, obese SHR rat. METHODS Sixteen week old SHR rats maintained on 14 hour daily photoperiods were treated daily for 16 days with bromocriptine (10 mg/kg, i.p.) or vehicle at 1 hour before light offset and, subsequent to blood pressure recordings on day 14, were then utilized for in vivo microdialysis of ventromedial hypothalamic catecholamine activity or sacrificed for the analyses of MS factors and regulators of hepatic metabolism. Normal Wistar rats served as wild-type controls for hypothalamic activity, body fat levels, and insulin sensitivity. RESULTS Bromocriptine treatment significantly reduced ventromedial hypothalamic norepinephrine and serotonin levels to the normal range and systolic and diastolic blood pressures, retroperitoneal body fat level, plasma insulin and glucose levels and HOMA-IR relative to vehicle treated SHR controls. Such treatment also reduced plasma levels of C-reactive protein, leptin, and norepinephrine and increased that of plasma adiponectin significantly relative to SHR controls. Finally, bromocriptine treatment significantly reduced hepatic levels of several pro-inflammatory pathway proteins and of the master transcriptional activators of lipogenesis, gluconeogenesis, and free fatty acid oxidation versus control SHR rats. CONCLUSION These findings indicate that in SHR rats, timed daily dopamine agonist treatment improves hypothalamic and neuroendocrine pathologies associated with MS and such neuroendocrine events are coupled to a transformation of liver metabolism potentiating a reduction of elevated lipogenic and gluconeogenic capacity. This liver effect may be driven in part by concurrent reductions in hyperinsulinemia and sympathetic tone as well as by reductions in intra-hepatic inflammation.
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78
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Luo Y, McKeehan WL. Stressed Liver and Muscle Call on Adipocytes with FGF21. Front Endocrinol (Lausanne) 2013; 4:194. [PMID: 24385972 PMCID: PMC3866528 DOI: 10.3389/fendo.2013.00194] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 12/04/2013] [Indexed: 01/03/2023] Open
Abstract
Fibroblast growth factor 21 (FGF21) is an emerging regulator of local and systemic metabolic homeostasis. Treatment with pharmacological levels of FGF21 alleviates obesity and associated metabolic diseases including diabetes. However, beyond anti-obesogenic effects, the normal roles and underlying mechanisms of FGF21 as an endocrine hormone remain unclear. A recent wave of studies has revealed that FGF21 is a stress-induced endocrine factor in liver, muscle, and other tissues that targets adipose tissue and adipocytes through the FGFR1-betaKlotho complex. Adipose tissues and adipocytes within diverse tissues respond with metabolites and adipokine signals that affect functions of body tissues systemically and cells within the local microenvironment adjacent to adipocytes. Normally this is to prevent impaired tissue-specific function and damage to diverse tissues secreting FGF21 in response to chronic stress. Therefore, diverse stressed tissues and the adipose tissue and adipocytes constitute a beneficial endocrine and paracrine communication network through FGF21. Here we attempt to unify these developments with beneficial pharmacological effects of FGF21 on obesity in respect to inter-organ stress communication and mechanisms.
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Affiliation(s)
- Yongde Luo
- IBT Proteomics and Nanotechnology Laboratory, Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
- *Correspondence: Yongde Luo, IBT Proteomics and Nanotechnology Laboratory, Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 W. Holcombe Blvd., Houston, TX 77030-3303, USA e-mail:
| | - Wallace L. McKeehan
- IBT Proteomics and Nanotechnology Laboratory, Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, USA
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79
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Chang CJ, Liou SS, Tzeng TF, Liu IM. The ethanol extract of Zingiber zerumbet Smith attenuates non-alcoholic fatty liver disease in hamsters fed on high-fat diet. Food Chem Toxicol 2013; 65:33-42. [PMID: 24342243 DOI: 10.1016/j.fct.2013.11.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Revised: 10/25/2013] [Accepted: 11/29/2013] [Indexed: 12/30/2022]
Abstract
The beneficial effects of the ethanol extract of Zingiber zerumbet rhizome (EEZZR) for use in the treatment of non-alcoholic fatty liver disease (NAFLD) were investigated. Syrian golden hamsters were fed a high-fat diet to induce NAFLD. EEZZR (100, 200, or 300mg/kg) were orally administered by gavage once daily for 8weeks. The higher plasma levels of total cholesterol, triglycerides, free fatty acids, and hepatic lipids, as well as the degree of insulin resistance were lowered by EEZZR. Histological evaluation of liver specimens demonstrated that the hepatic steatosis of EEZZR-treated groups was improved. EEZZR decreased hepatic mRNA levels of sterol regulatory element-binding protein-1c and its lipogenic target genes. The hepatic mRNA expression of peroxisome proliferator-activated receptor α, together with its target genes responsible for β-oxidation of fatty acids were also upregulated by EEZZR. In conclusion, these findings suggest that EEZZR has the promising potential to ameliorate NAFLD.
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Affiliation(s)
- Chia Ju Chang
- Department of Pharmacy & Graduate Institute of Pharmaceutical Technology, Tajen University, Yanpu Shiang, Ping Tung Shien, Taiwan, ROC
| | - Shorong-Shii Liou
- Department of Pharmacy & Graduate Institute of Pharmaceutical Technology, Tajen University, Yanpu Shiang, Ping Tung Shien, Taiwan, ROC
| | - Thing-Fong Tzeng
- Department of Pharmacy & Graduate Institute of Pharmaceutical Technology, Tajen University, Yanpu Shiang, Ping Tung Shien, Taiwan, ROC
| | - I-Min Liu
- Department of Pharmacy & Graduate Institute of Pharmaceutical Technology, Tajen University, Yanpu Shiang, Ping Tung Shien, Taiwan, ROC.
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Pessentheiner AR, Pelzmann HJ, Walenta E, Schweiger M, Groschner LN, Graier WF, Kolb D, Uno K, Miyazaki T, Nitta A, Rieder D, Prokesch A, Bogner-Strauss JG. NAT8L (N-acetyltransferase 8-like) accelerates lipid turnover and increases energy expenditure in brown adipocytes. J Biol Chem 2013; 288:36040-51. [PMID: 24155240 PMCID: PMC3861652 DOI: 10.1074/jbc.m113.491324] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
NAT8L (N-acetyltransferase 8-like) catalyzes the formation of N-acetylaspartate (NAA) from acetyl-CoA and aspartate. In the brain, NAA delivers the acetate moiety for synthesis of acetyl-CoA that is further used for fatty acid generation. However, its function in other tissues remained elusive. Here, we show for the first time that Nat8l is highly expressed in adipose tissues and murine and human adipogenic cell lines and is localized in the mitochondria of brown adipocytes. Stable overexpression of Nat8l in immortalized brown adipogenic cells strongly increases glucose incorporation into neutral lipids, accompanied by increased lipolysis, indicating an accelerated lipid turnover. Additionally, mitochondrial mass and number as well as oxygen consumption are elevated upon Nat8l overexpression. Concordantly, expression levels of brown marker genes, such as Prdm16, Cidea, Pgc1α, Pparα, and particularly UCP1, are markedly elevated in these cells. Treatment with a PPARα antagonist indicates that the increase in UCP1 expression and oxygen consumption is PPARα-dependent. Nat8l knockdown in brown adipocytes has no impact on cellular triglyceride content, lipogenesis, or oxygen consumption, but lipolysis and brown marker gene expression are increased; the latter is also observed in BAT of Nat8l-KO mice. Interestingly, the expression of ATP-citrate lyase is increased in Nat8l-silenced adipocytes and BAT of Nat8l-KO mice, indicating a compensatory mechanism to sustain the acetyl-CoA pool once Nat8l levels are reduced. Taken together, our data show that Nat8l impacts on the brown adipogenic phenotype and suggests the existence of the NAT8L-driven NAA metabolism as a novel pathway to provide cytosolic acetyl-CoA for lipid synthesis in adipocytes.
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Affiliation(s)
- Ariane R. Pessentheiner
- From the Institute for Genomics and Bioinformatics, Graz University of Technology, Petergasse 14, 8010 Graz, Austria, ,the Institute of Biochemistry, Graz University of Technology, Petergasse 12, 8010 Graz, Austria
| | - Helmut J. Pelzmann
- From the Institute for Genomics and Bioinformatics, Graz University of Technology, Petergasse 14, 8010 Graz, Austria, ,the Institute of Biochemistry, Graz University of Technology, Petergasse 12, 8010 Graz, Austria
| | - Evelyn Walenta
- From the Institute for Genomics and Bioinformatics, Graz University of Technology, Petergasse 14, 8010 Graz, Austria
| | - Martina Schweiger
- the Institute for Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | | | | | - Dagmar Kolb
- Institute of Cell Biology, Histology, and Embryology, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria, ,the Core Facility Ultrastructure Analysis, Center for Medical Research, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
| | - Kyosuke Uno
- the Department of Pharmaceutical Therapy and Neuropharmacology, Faculty of Pharmaceutical Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan, and
| | - Toh Miyazaki
- the Department of Pharmaceutical Therapy and Neuropharmacology, Faculty of Pharmaceutical Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan, and
| | - Atsumi Nitta
- the Department of Pharmaceutical Therapy and Neuropharmacology, Faculty of Pharmaceutical Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan, and
| | - Dietmar Rieder
- the Division of Bioinformatics, Biocenter, Innsbruck Medical University, Innrain 80, 6020 Innsbruck, Austria
| | - Andreas Prokesch
- From the Institute for Genomics and Bioinformatics, Graz University of Technology, Petergasse 14, 8010 Graz, Austria, ,the Institute of Biochemistry, Graz University of Technology, Petergasse 12, 8010 Graz, Austria
| | - Juliane G. Bogner-Strauss
- From the Institute for Genomics and Bioinformatics, Graz University of Technology, Petergasse 14, 8010 Graz, Austria, ,the Institute of Biochemistry, Graz University of Technology, Petergasse 12, 8010 Graz, Austria, , To whom correspondence should be addressed: Petersgasse 14/5, 8010 Graz, Austria. Tel.: 43-316-873-5337; E-mail:
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Grape seed proanthocyanidin rescues rats from steatosis: a comparative and combination study with metformin. J Lipids 2013; 2013:153897. [PMID: 24307947 PMCID: PMC3836386 DOI: 10.1155/2013/153897] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 09/05/2013] [Indexed: 12/26/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD), a premorbid condition, lacks proper management owing to multitude of abnormalities. In this study, we compared the effects of a potent antioxidant, grape seed proanthocyanidins (GSP), and an insulin sensitizer, metformin (MET), in high-fat-fructose-diet- (HFFD-) induced albino Wistar rat model of NAFLD. Either GSP (100 mg/Kg b.w) or MET (50 mg/Kg b.w) or both were administered as therapeutic options. HFFD-fed rats showed abnormal plasma lipid profile, inflammation, and steatosis of the liver when examined by biochemical and histology techniques. Increased lipid storage, lipogenesis, and reduced lipolysis were evident from mRNA expression studies of hepatic lipid droplets (LD) proteins, sterol regulatory element binding 1c (SREBP 1c), and peroxisome proliferator activated receptor- α (PPAR- α ). GSP administration to HFFD-fed rats caused 69% reduction in hepatic TG levels, whereas MET caused only 23%. The combination treatment reduced TG levels by 63%. GSP reduced the mRNA expression of SREBP1c and LD proteins and increased that of PPAR- α more effectively compared to MET in HFFD-induced hyperlipidemic rats. Combination of MET and GSP improved the metabolism of lipids effectively, but the effect was not additive in restoring lipid levels.
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Zerumbone, a Natural Cyclic Sesquiterpene of Zingiber zerumbet Smith, Attenuates Nonalcoholic Fatty Liver Disease in Hamsters Fed on High-Fat Diet. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:303061. [PMID: 24223615 PMCID: PMC3810186 DOI: 10.1155/2013/303061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 08/08/2013] [Indexed: 12/18/2022]
Abstract
We investigated the effects of zerumbone, a natural cyclic sesquiterpene, on hepatic lipid metabolism in Syrian golden hamsters fed on high-fat diet (HFD). After being fed HFD for 2 weeks, hamsters were dosed orally with zerumbone (75, 150, and 300 mg kg(-1)) once daily for 8 weeks. After treatment with zerumbone, the plasma levels of total cholesterol (TC) and triglycerides (TGs) and the contents of TC and TG in hepatic tissue as well as homeostasis model assessment of insulin resistance were lowered, especially in the zerumbone-treated group (300 mg kg(-1)). Moreover, the histological evaluation of liver specimens demonstrated that the steatosis and inflammation in liver of zerumbone-treated groups were improved. Zerumbone exhibited the ability to decrease hepatic mRNA levels of sterol regulatory element-binding protein-1c and its lipogenic target genes, such as fatty acid synthase, acetyl-CoA carboxylase 1, and stearoyl-CoA desaturase 1. The hepatic mRNA expression of peroxisome proliferator-activated receptor α , together with its target genes including carnitine palmitoyl transferase-1, acyl-CoA oxidase, and acyl-CoA oxidase 1, was also upregulated by zerumbone. In conclusion, zerumbone improves insulin sensitivity, decreases lipogenesis, and increases lipid oxidation in the liver of HFD-fed hamsters, implying a potential application in the treatment of nonalcoholic fatty liver disease.
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Ford NA, Elsen AC, Erdman JW. Genetic ablation of carotene oxygenases and consumption of lycopene or tomato powder diets modulate carotenoid and lipid metabolism in mice. Nutr Res 2013; 33:733-42. [PMID: 24034573 DOI: 10.1016/j.nutres.2013.07.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/05/2013] [Accepted: 07/08/2013] [Indexed: 11/27/2022]
Abstract
Carotene-15,15'-monooxygenase (CMO-I) cleaves β-carotene to form vitamin A, whereas carotene-9',10'-monooxygenase (CMO-II) preferentially cleaves non-provitamin A carotenoids. Recent reports indicate that β-carotene metabolites regulate dietary lipid uptake, whereas lycopene regulates peroxisome proliferator-activated receptor expression. To determine the physiologic consequences of carotenoids and their interactions with CMO-I and CMO-II, we characterized mammalian carotenoid metabolism, metabolic perturbations, and lipid metabolism in female CMO-I(-/-) and CMO-II(-/-) mice fed lycopene or tomato-containing diets for 30 days. We hypothesized that there would be significant interactions between diet and genotype on carotenoid accumulation and lipid parameters. CMO-I(-/-) mice had higher levels of leptin, insulin, and hepatic lipidosis but lower levels of serum cholesterol. CMO-II(-/-) mice had increased tissue lycopene and phytofluene accumulation, reduced insulin-like growth factor 1 levels and cholesterol levels, but elevated liver lipids and cholesterol compared with wild-type mice. The diets did not modulate these genotypic perturbations, but lycopene and tomato powder significantly decreased serum insulin-like growth factor 1. Tomato powder also increased hepatic peroxisome proliferator-activated receptor expression, independent of genotype. These data point to the pleiotropic actions of CMO-I and CMO-II supporting a strong role of these proteins in regulating tissue carotenoid accumulation and the lipid metabolic phenotype as well as tomato carotenoid-independent regulation of lipid metabolism.
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Affiliation(s)
- Nikki A Ford
- Department of Nutritional Sciences, University of Texas at Austin, Austin TX 78723, USA
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He J, Gao J, Xu M, Ren S, Stefanovic-Racic M, O'Doherty RM, Xie W. PXR ablation alleviates diet-induced and genetic obesity and insulin resistance in mice. Diabetes 2013; 62:1876-87. [PMID: 23349477 PMCID: PMC3661619 DOI: 10.2337/db12-1039] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The pregnane X receptor (PXR), along with its sister receptor constitutive androstane receptor (CAR), was initially characterized as a xenobiotic receptor that regulates drug metabolism. In this study, we have uncovered an unexpected endobiotic role of PXR in obesity and type 2 diabetes. PXR ablation inhibited high-fat diet (HFD)-induced obesity, hepatic steatosis, and insulin resistance, which were accounted for by increased oxygen consumption, increased mitochondrial β-oxidation, inhibition of hepatic lipogenesis and inflammation, and sensitization of insulin signaling. In an independent model, introducing the PXR(-/-) allele into the ob/ob background also improved body composition and relieved the diabetic phenotype. The ob/ob mice deficient of PXR showed increased oxygen consumption and energy expenditure, as well as inhibition of gluconeogenesis and increased rate of glucose disposal during euglycemic clamp. Mechanistically, the metabolic benefits of PXR ablation were associated with the inhibition of c-Jun NH2-terminal kinase activation and downregulation of lipin-1, a novel PXR target gene. The metabolic benefit of PXR ablation was opposite to the reported prodiabetic effect of CAR ablation. Our results may help to establish PXR as a novel therapeutic target, and PXR antagonists may be used for the prevention and treatment of obesity and type 2 diabetes.
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Affiliation(s)
- Jinhan He
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pharmacy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jie Gao
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Meishu Xu
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Songrong Ren
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Maja Stefanovic-Racic
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert Martin O'Doherty
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Wen Xie,
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85
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Conn CA, Vaughan RA, Garver WS. Nutritional Genetics and Energy Metabolism in Human Obesity. Curr Nutr Rep 2013. [DOI: 10.1007/s13668-013-0046-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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86
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Zhang X, Wu C, Wu H, Sheng L, Su Y, Zhang X, Luan H, Sun G, Sun X, Tian Y, Ji Y, Guo P, Xu X. Anti-hyperlipidemic effects and potential mechanisms of action of the caffeoylquinic acid-rich Pandanus tectorius fruit extract in hamsters fed a high fat-diet. PLoS One 2013; 8:e61922. [PMID: 23613974 PMCID: PMC3628350 DOI: 10.1371/journal.pone.0061922] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 03/15/2013] [Indexed: 12/20/2022] Open
Abstract
Hyperlipidemia is considered to be one of the greatest risk factors contributing to the prevalence and severity of cardiovascular diseases. In this work, we investigated the anti-hyperlipidemic effect and potential mechanism of action of the Pandanus tectorius fruit extract in hamsters fed a high fat-diet (HFD). The n-butanol fraction of the P. tectorius fruit ethanol extract (PTF-b) was rich in caffeoylquinic acids (CQAs). Administration of PTF-b for 4 weeks effectively decreased retroperitoneal fat and the serum levels of total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-c) and hepatic TC and TG. The lipid signals (fatty acids, and cholesterol) in the liver as determined by nuclear magnetic resonance (NMR) were correspondingly reduced. Realtime quantitative PCR showed that the mRNA levels of PPARα and PPARα-regulated genes such as ACO, CPT1, LPL and HSL were largely enhanced by PTF-b. The transcription of LDLR, CYP7A1, and PPARγ was also upregulated. Treatment with PTF-b significantly stimulated the activation of AMP-activated protein kinase (AMPK) as well as the activity of serum and hepatic lipoprotein lipase (LPL). Together, these results suggest that administration of the PTF-b enriched in CQAs moderates hyperlipidemia and improves the liver lipid profile. These effects may be caused, at least in part, by increasing the expression of PPARα and its downstream genes and by upregulation of LPL and AMPK activities.
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Affiliation(s)
- Xiaopo Zhang
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Chongming Wu
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Haifeng Wu
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | | | - Yan Su
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- Research Centre on Life Sciences and Environment Sciences, Harbin University of Commerce, Harbin, China
| | - Xue Zhang
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- Research Centre on Life Sciences and Environment Sciences, Harbin University of Commerce, Harbin, China
| | - Hong Luan
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- Research Centre on Life Sciences and Environment Sciences, Harbin University of Commerce, Harbin, China
| | - Guibo Sun
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Xiaobo Sun
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Yu Tian
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Yubin Ji
- Research Centre on Life Sciences and Environment Sciences, Harbin University of Commerce, Harbin, China
| | - Peng Guo
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- * E-mail: (PG); (XX)
| | - Xudong Xu
- Pharmacology and Toxicology Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
- * E-mail: (PG); (XX)
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87
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tert-Butylhydroquinone reduces lipid accumulation in C57BL/6 mice with lower body weight gain. Arch Pharm Res 2013; 36:897-904. [DOI: 10.1007/s12272-013-0109-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 03/24/2013] [Indexed: 01/10/2023]
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88
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Misra P, Viswakarma N, Reddy JK. Peroxisome proliferator-activated receptor-α signaling in hepatocarcinogenesis. Subcell Biochem 2013; 69:77-99. [PMID: 23821144 DOI: 10.1007/978-94-007-6889-5_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Peroxisomes are subcellular organelles that are found in the cytoplasm of most animal cells. They perform diverse metabolic functions, including H2O2-derived respiration, β-oxidation of fatty acids, and cholesterol metabolism. Peroxisome proliferators are a large class of structurally dissimilar industrial and pharmaceutical chemicals that were originally identified as inducers of both the size and the number of peroxisomes in rat and mouse livers or hepatocytes in vitro. Exposure to peroxisome proliferators leads to a stereotypical orchestration of adaptations consisting of hepatocellular hypertrophy and hyperplasia, and transcriptional induction of fatty acid metabolizing enzymes regulated in parallel with peroxisome proliferation. Chronic exposure to peroxisome proliferators causes liver tumors in both male and female mice and rats. Evidence indicates a pivotal role for a subset of nuclear receptor superfamily members, called peroxisome proliferator-activated receptors (PPARs), in mediating energy metabolism. Upon activation, PPARs regulate the expression of genes involved in lipid metabolism and peroxisome proliferation, as well as genes involved in cell growth. In this review, we describe the molecular mode of action of PPAR transcription factors, including ligand binding, interaction with specific DNA response elements, transcriptional activation, and cross talk with other signaling pathways. We discuss the evidence that suggests that PPARα and transcriptional coactivator Med1/PBP, a key subunit of the Mediator complex play a central role in mediating hepatic steatosis to hepatocarcinogenesis. Disproportionate increases in H2O2-generating enzymes generates excess reactive oxygen species resulting in sustained oxidative stress and progressive endoplasmic reticulum (ER) stress with activation of unfolded protein response signaling. Thus, these major contributors coupled with hepatocellular proliferation are the key players of peroxisome proliferators-induced hepatocarcinogenesis.
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Affiliation(s)
- Parimal Misra
- Department of Biology, Dr. Reddy's Institute of Life Sciences, An Associate Institute of University of Hyderabad, Gachibowli, Hyderabad, 500046, India,
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89
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Zhang H, Shen WJ, Cortez Y, Kraemer FB, Azhar S. Nordihydroguaiaretic acid improves metabolic dysregulation and aberrant hepatic lipid metabolism in mice by both PPARα-dependent and -independent pathways. Am J Physiol Gastrointest Liver Physiol 2013; 304:G72-86. [PMID: 23104557 PMCID: PMC3543637 DOI: 10.1152/ajpgi.00328.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Creosote bush-derived nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, possesses antioxidant properties and functions as a potent antihyperlipidemic agent in rodent models. Here, we examined the effect of chronic NDGA treatment of ob/ob mice on plasma dyslipidemia, hepatic steatosis, and changes in hepatic gene expression. Feeding ob/ob mice a chow diet supplemented with either low (0.83 g/kg diet) or high-dose (2.5 g/kg diet) NDGA for 16 wk significantly improved plasma triglyceride (TG), inflammatory chemokine levels, hyperinsulinemia, insulin sensitivity, and glucose intolerance. NDGA treatment caused a marked reduction in liver weight and TG content, while enhancing rates of fatty acid oxidation. Microarray analysis of hepatic gene expression demonstrated that NDGA treatment altered genes for lipid metabolism, with genes involved in fatty acid catabolism most significantly increased. NDGA upregulated the mRNA and nuclear protein levels of peroxisome proliferator-activated receptor α (PPARα), and the activated (phosphorylated) form of AMP-activated kinase. NDGA increased PPARα promoter activity in AML12 hepatocytes and also prevented the fatty acid suppression of PPARα expression. In contrast, PPARα siRNA abrogated the stimulatory effect of NDGA on fatty acid catabolism. Likewise, no stimulatory effect of NDGA on hepatic fatty acid oxidation was observed in the livers of PPARα-deficient mice, but the ability of NDGA to reverse fatty liver conditions was unaffected. In conclusion, the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation via PPARα-dependent pathways. However, PPARα-independent pathways also contribute to NDGA's action to ameliorate hepatic steatosis.
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Affiliation(s)
- Haiyan Zhang
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Wen-Jun Shen
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Yuan Cortez
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California;
| | - Fredric B. Kraemer
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Salman Azhar
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,3Gastroenterology and Hepatology, Stanford University, Stanford, California
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90
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Basseri S, Lhoták Š, Fullerton MD, Palanivel R, Jiang H, Lynn EG, Ford RJ, Maclean KN, Steinberg GR, Austin RC. Loss of TDAG51 results in mature-onset obesity, hepatic steatosis, and insulin resistance by regulating lipogenesis. Diabetes 2013; 62:158-69. [PMID: 22961087 PMCID: PMC3526025 DOI: 10.2337/db12-0256] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Regulation of energy metabolism is critical for the prevention of obesity, diabetes, and hepatic steatosis. Here, we report an important role for the pleckstrin homology-related domain family member, T-cell death-associated gene 51 (TDAG51), in the regulation of energy metabolism. TDAG51 expression was examined during adipocyte differentiation. Adipogenic potential of preadipocytes with knockdown or absence of TDAG51 was assessed. Weight gain, insulin sensitivity, metabolic rate, and liver lipid content were also compared between TDAG51-deficient (TDAG51(-/-)) and wild-type mice. In addition to its relatively high expression in liver, TDAG51 was also present in white adipose tissue (WAT). TDAG51 was downregulated during adipogenesis, and TDAG51(-/-) preadipocytes exhibited greater lipogenic potential. TDAG51(-/-) mice fed a chow diet exhibited greater body and WAT mass, had reduced energy expenditure, displayed mature-onset insulin resistance (IR), and were predisposed to hepatic steatosis. TDAG51(-/-) mice had increased hepatic triglycerides and SREBP-1 target gene expression. Furthermore, TDAG51 expression was inversely correlated with fatty liver in multiple mouse models of hepatic steatosis. Taken together, our findings suggest that TDAG51 is involved in energy homeostasis at least in part by regulating lipogenesis in liver and WAT, and hence, may constitute a novel therapeutic target for the treatment of obesity and IR.
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Affiliation(s)
- Sana Basseri
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Hamilton Centre for Kidney Research, St. Joseph’s Healthcare Hamilton, Hamilton, Ontario, Canada
| | - Šárka Lhoták
- Hamilton Centre for Kidney Research, St. Joseph’s Healthcare Hamilton, Hamilton, Ontario, Canada
| | - Morgan D. Fullerton
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Rengasamy Palanivel
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Hua Jiang
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | - Edward G. Lynn
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Hamilton Centre for Kidney Research, St. Joseph’s Healthcare Hamilton, Hamilton, Ontario, Canada
| | - Rebecca J. Ford
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Kenneth N. Maclean
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado
| | - Gregory R. Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Richard C. Austin
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Hamilton Centre for Kidney Research, St. Joseph’s Healthcare Hamilton, Hamilton, Ontario, Canada
- Corresponding author: Richard C. Austin,
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91
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Newman JC, He W, Verdin E. Mitochondrial protein acylation and intermediary metabolism: regulation by sirtuins and implications for metabolic disease. J Biol Chem 2012; 287:42436-43. [PMID: 23086951 DOI: 10.1074/jbc.r112.404863] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The sirtuins are a family of NAD(+)-dependent protein deacetylases that regulate cell survival, metabolism, and longevity. Three sirtuins, SIRT3-5, localize to mitochondria. Expression of SIRT3 is selectively activated during fasting and calorie restriction. SIRT3 regulates the acetylation level and enzymatic activity of key metabolic enzymes, such as acetyl-CoA synthetase, long-chain acyl-CoA dehydrogenase, and 3-hydroxy-3-methylglutaryl-CoA synthase 2, and enhances fat metabolism during fasting. SIRT5 exhibits demalonylase/desuccinylase activity, and lysine succinylation and malonylation are abundant mitochondrial protein modifications. No convincing enzymatic activity has been reported for SIRT4. Here, we review the emerging role of mitochondrial sirtuins as metabolic sensors that respond to changes in the energy status of the cell and modulate the activities of key metabolic enzymes via protein deacylation.
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Affiliation(s)
- John C Newman
- Gladstone Institute of Virology and Immunology, San Francisco, California 94158, USA
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92
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Kawai D, Takaki A, Nakatsuka A, Wada J, Tamaki N, Yasunaka T, Koike K, Tsuzaki R, Matsumoto K, Miyake Y, Shiraha H, Morita M, Makino H, Yamamoto K. Hydrogen-rich water prevents progression of nonalcoholic steatohepatitis and accompanying hepatocarcinogenesis in mice. Hepatology 2012; 56:912-21. [PMID: 22505328 DOI: 10.1002/hep.25782] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2011] [Accepted: 03/07/2012] [Indexed: 12/12/2022]
Abstract
UNLABELLED Oxidative stress is a strong contributor to the progression from simple fatty liver to nonalcoholic steatohepatitis (NASH). Molecular hydrogen is an effective antioxidant that reduces cytotoxic reactive oxygen species. In this study, we investigated the effects of hydrogen-rich water and the drug pioglitazone on the progression of NASH in mouse models. A methionine-choline-deficient (MCD) diet mouse model was prepared. Mice were divided into three experimental groups and fed for 8 weeks as follows: (1) MCD diet + control water (CW group); (2) MCD diet + hydrogen-rich water (HW group); and (3) MCD diet mixed with pioglitazone (PGZ group). Plasma alanine aminotransferase levels, hepatic expression of tumor necrosis factor-α, interleukin-6, fatty acid synthesis-related genes, oxidative stress biomarker 8-hydroxydeoxyguanosine (8-OHdG), and apoptosis marker terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive cells in the liver were decreased in the HW and PGZ groups. The HW group showed a smaller decrease in hepatic cholesterol; however, stronger antioxidative effects in serum and lower peroxisome proliferator-activated receptor-α expression in the liver were seen in comparison with the PGZ group. We then investigated the effects of hydrogen in the prevention of hepatocarcinogenesis in STAM mice, known as the NASH-related hepatocarcinogenesis model. Eight-week-old male STAM mice were divided into three experimental groups as follows: (1) control water (CW-STAM); (2) hydrogen-rich water (HW-STAM); and (3) pioglitazone (PGZ-STAM). After 8 weeks, hepatic tumors were evaluated. The number of tumors was significantly lower in the HW-STAM and PGZ-STAM groups than in the CW-STAM group. The maximum tumor size was smaller in the HW-STAM group than in the other groups. CONCLUSION Consumption of hydrogen-rich water may be an effective treatment for NASH by reducing hepatic oxidative stress, apoptosis, inflammation, and hepatocarcinogenesis.
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Affiliation(s)
- Daisuke Kawai
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City, Okayama, Japan
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93
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Tryndyak V, de Conti A, Kobets T, Kutanzi K, Koturbash I, Han T, Fuscoe JC, Latendresse JR, Melnyk S, Shymonyak S, Collins L, Ross SA, Rusyn I, Beland FA, Pogribny IP. Interstrain differences in the severity of liver injury induced by a choline- and folate-deficient diet in mice are associated with dysregulation of genes involved in lipid metabolism. FASEB J 2012; 26:4592-602. [PMID: 22872676 DOI: 10.1096/fj.12-209569] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major health problem and a leading cause of chronic liver disease in the United States and developed countries. In humans, genetic factors greatly influence individual susceptibility to NAFLD. The goals of this study were to compare the magnitude of interindividual differences in the severity of liver injury induced by methyl-donor deficiency among individual inbred strains of mice and to investigate the underlying mechanisms associated with the variability. Feeding mice a choline- and folate-deficient diet for 12 wk caused liver injury similar to NAFLD. The magnitude of liver injury varied among the strains, with the order of sensitivity being A/J ≈ C57BL/6J ≈ C3H/HeJ < 129S1/SvImJ ≈ CAST/EiJ < PWK/PhJ < WSB/EiJ. The interstrain variability in severity of NAFLD liver damage was associated with dysregulation of genes involved in lipid metabolism, primarily with a down-regulation of the peroxisome proliferator receptor α (PPARα)-regulated lipid catabolic pathway genes. Markers of oxidative stress and oxidative stress-induced DNA damage were also elevated in the livers but were not correlated with severity of liver damage. These findings suggest that the PPARα-regulated metabolism network is one of the key mechanisms determining interstrain susceptibility and severity of NAFLD in mice.
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Affiliation(s)
- Volodymyr Tryndyak
- Division of Biochemical Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas 72079, USA
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94
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Cianfarani S, Agostoni C, Bedogni G, Berni Canani R, Brambilla P, Nobili V, Pietrobelli A. Effect of intrauterine growth retardation on liver and long-term metabolic risk. Int J Obes (Lond) 2012; 36:1270-7. [PMID: 22531091 DOI: 10.1038/ijo.2012.54] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Intrauterine growth retardation predisposes toward long-term morbidity from type 2 diabetes and cardiovascular disease. To explain this association, the concept of programming was introduced to indicate a process whereby a stimulus or insult at a critical period of development has lasting or lifelong consequences on key endocrine and metabolic pathways. Subtle changes in cell composition of tissues, induced by suboptimal conditions in utero, can influence postnatal physiological functions. There is increasing evidence, suggesting that liver may represent one of the candidate organs targeted by programming, undergoing structural, functional and epigenetic changes following exposure to an unfavorable intrauterine environment. The aim of this review is to provide insights into the molecular mechanisms underlying liver programming that contribute to increase the cardiometabolic risk in subjects with intrauterine growth restriction.
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Affiliation(s)
- S Cianfarani
- Molecular Endocrinology Unit-DPUO, Bambino Gesù Children's Hospital - 'Rina Balducci' Center of Pediatric Endocrinology, Tor Vergata University, Rome, Italy.
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95
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Tyra HM, Spitz DR, Rutkowski DT. Inhibition of fatty acid oxidation enhances oxidative protein folding and protects hepatocytes from endoplasmic reticulum stress. Mol Biol Cell 2012; 23:811-9. [PMID: 22262455 PMCID: PMC3290641 DOI: 10.1091/mbc.e11-12-1011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The unfolded protein response regulates lipid metabolism, but the functional benefit of this regulation to ER function is not clear. This work shows that inhibition of fatty acid oxidation raises cellular oxidation potential, facilitates ER oxidative folding, and protects hepatocytes from ER stress. The unfolded protein response (UPR) signals protein misfolding in the endoplasmic reticulum (ER) to effect gene expression changes and restore ER homeostasis. Although many UPR-regulated genes encode ER protein processing factors, others, such as those encoding lipid catabolism enzymes, seem unrelated to ER function. It is not known whether UPR-mediated inhibition of fatty acid oxidation influences ER function or, if so, by what mechanism. Here we demonstrate that pharmacological or genetic inhibition of fatty acid oxidation renders liver cells partially resistant to ER stress–induced UPR activation both in vitro and in vivo. Reduced stress sensitivity appeared to be a consequence of increased cellular redox potential as judged by an elevated ratio of oxidized to reduced glutathione and enhanced oxidative folding in the ER. Accordingly, the ER folding benefit of inhibiting fatty acid (FA) oxidation could be phenocopied by manipulating glutathione recycling during ER stress. Conversely, preventing cellular hyperoxidation with N-acetyl cysteine partially negated the stress resistance provided by blocking FA oxidation. Our results suggest that ER stress can be ameliorated through alteration of the oxidizing environment within the ER lumen, and they provide a potential logic for the transient regulation of metabolic pathways by the UPR during stress.
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Affiliation(s)
- Heather M Tyra
- Department of Anatomy and Cell Biology and Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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