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Becattini B, Breasson L, Sardi C, Zani F, Solinas G. PI3Kγ promotes obesity-associated hepatocellular carcinoma by regulating metabolism and inflammation. JHEP Rep 2021; 3:100359. [PMID: 34704005 PMCID: PMC8521290 DOI: 10.1016/j.jhepr.2021.100359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 08/17/2021] [Accepted: 08/23/2021] [Indexed: 01/08/2023] Open
Abstract
Background & Aims Phosphatidylinositides-3 kinases (PI3Ks) are promising drug targets for cancer therapy, but blockage of PI3K-AKT signalling causes hyperglycaemia, hyperinsulinaemia, and liver damage in patients, and hepatocellular carcinoma (HCC) in mice. There are 4 PI3Ks: PI3Kα, PI3Kβ, PI3Kδ, and PI3Kγ. The role of PI3Kγ in HCC is unknown. Methods We performed histopathological, metabolic, and molecular phenotyping of mice with genetic ablation of PI3Kγ using models where HCC was initiated by the carcinogen diethylnitrosamine (DEN) and promoted by dietary or genetic obesity (ob/ob). The role of PI3Kγ in leucocytes was investigated in mice lacking PI3Kγ in haematopoietic and endothelial cells. Results Loss of PI3Kγ had no effects on the development of DEN-induced HCC in lean mice. However, in mice injected with DEN and placed on an obesogenic diet, PI3Kγ ablation reduced tumour growth, which was associated with reduced insulinaemia, steatosis, and expression of inflammatory cytokines. ob/ob mice lacking PI3Kγ, and mice with diet-induced obesity lacking PI3Kγ in leucocytes and endothelial cells did not display improved insulin sensitivity, steatosis, metabolic inflammation, or reduced tumour growth. However, these mice showed a reduced number of tumours, reduced liver infiltration by neutrophils, and reduced hepatocyte proliferation acutely induced by DEN. Conclusions Loss of PI3Kγ reduces tumour development in obesity-promoted HCC through multiple cell types and mechanisms that include improved insulinaemia, steatosis, and metabolic inflammation as well as the regulation of acute neutrophil infiltration and compensatory hepatocyte proliferation. PI3Kγ-selective inhibition may represent a novel therapeutic approach to reduce HCC initiation and slow HCC progression. Lay summary Class-1 phosphatidylinositides-3 kinases (PI3Ks) are critical targets in cancer therapy, but complete inhibition of all isoforms causes liver damage, hyperglycaemia, and insulinaemia. Here we show that selective ablation of the PI3Kγ isoform dampens tumour initiation and growth in a mouse model of carcinogen-initiated and obesity-promoted hepatocellular carcinoma (HCC). The effect of PI3Kγ ablation on reduced tumour growth was explained by reduced tumour cell proliferation, which was associated with reduced insulin levels, liver lipids, and reduced expression of tumour-promoting cytokines. PI3Kγ ablation in leucocytes of obese mice had no effects on tumour size. However, it reduced tumour number in association with reduced carcinogen-induced neutrophil infiltration and hepatocyte proliferation in livers of obese mice. Inhibition of PI3Kγ may thus reduce HCC initiation and growth in obese subjects by a mechanism involving reduced metabolic stress and insulinaemia and reduced carcinogen-induced neutrophil infiltration to the fatty liver. PI3Kγ ablation does not affect carcinogen-induced liver cancer in lean mice. PI3Kγ ablation reduces carcinogen-induced liver cancer in obese mice. Systemic PI3Kγ ablation reduces hyperinsulinaemia, steatosis, metabolic inflammation, and growth of liver tumours. PI3Kγ ablation in leucocytes and endothelial cells reduces neutrophil infiltration and hepatocyte proliferation acutely induced by carcinogen in the fatty liver.
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Key Words
- AKT
- AST, aspartate aminotransferase
- BMDM, bone marrow-derived macrophages
- DEN, diethylnitrosamine
- GTT, glucose tolerance test
- HCC, hepatocellular carcinoma
- HFD, high-fat diet
- ITT, insulin tolerance test
- Insulin
- NAFLD
- NASH
- PI3K, phosphatidylinositides-3 kinase
- PTEN, phosphatase and tensin homolog
- RT, room temperature
- TUNEL, terminal deoxynucleotidyl transferase dUTP nick-end labelling
- WT, wild-type
- mTOR
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Affiliation(s)
- Barbara Becattini
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine at Institute of Medicine, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ludovic Breasson
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine at Institute of Medicine, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Claudia Sardi
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine at Institute of Medicine, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | | | - Giovanni Solinas
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine at Institute of Medicine, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
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Disotuar MM, Smith JA, Li J, Alam S, Lin NP, Chou DH. Facile synthesis of insulin fusion derivatives through sortase A ligation. Acta Pharm Sin B 2021; 11:2719-25. [PMID: 34589392 DOI: 10.1016/j.apsb.2020.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/29/2020] [Accepted: 11/12/2020] [Indexed: 11/22/2022] Open
Abstract
Insulin derivatives such as insulin detemir and insulin degludec are U.S. Food and Drug Administration (FDA)-approved long-acting insulin currently used by millions of people with diabetes. These derivatives are modified in C-terminal B29 lysine to retain insulin bioactivity. New and efficient methods for facile synthesis of insulin derivatives may lead to new discovery of therapeutic insulin. Herein, we report a new method using sortase A (SrtA)-mediated ligation for the synthesis of insulin derivatives with high efficiency and functional group tolerance in the C-terminal B chain. This new insulin molecule (Ins-SA) with an SrtA-recognizing motif can be conjugated to diverse groups with N-terminal oligoglycines to generate new insulin derivatives. We further demonstrated that a new insulin derivative synthesized by this SrtA-mediated ligation shows strong cellular and in vivo bioactivity. This enzymatic method can therefore be used for future insulin design and development.
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Key Words
- Alb, albumin
- Albumin-binding peptide SA21
- Boc, tert-butyloxycarbonyl
- DCM, dichloromethane
- DIEA, N,N-diisopropylethylamine
- DMEM, Dulbecco's Modified Eagle Medium
- DMF, dimethylformamide
- DMSO, dimethyl sulfoxide
- DOI, desoctapeptide (B23−30) insulin
- Diabetes mellitus
- EDT, 1,2-ethanedithiol
- FBS, fetal bovine serum
- Fmoc, 9-fluorenylmethoxycarbonyl
- HATU, 1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate
- HBTU, O-(benxontriazol-1-yl)-1,1,3,3-tetramethyluronium
- HPLC, high performance liquid chromatography
- HTRF, homogeneous time resolved fluorescence
- IR-B, human insulin receptor isoform B
- ITT, insulin tolerance test
- Insulin synthesis
- LC‒MS, liquid chromatography mass spectrometry
- Long-acting insulin
- Mtt, 4-methyltrityl
- NBD-X, 6-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)hexanoic acid
- STZ, streptozotocin
- Sortase A (SrtA) ligation
- SrtA, sortase A
- THF, triflouroacetic acid
- TIS, triisoproylsilane
- i.p., intraperitoneal
- pAkt, phosphorylated protein kinase B
- t-Bu, tert-butyl
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Ding L, Yang Q, Zhang E, Wang Y, Sun S, Yang Y, Tian T, Ju Z, Jiang L, Wang X, Wang Z, Huang W, Yang L. Notoginsenoside Ft1 acts as a TGR5 agonist but FXR antagonist to alleviate high fat diet-induced obesity and insulin resistance in mice. Acta Pharm Sin B 2021; 11:1541-1554. [PMID: 34221867 PMCID: PMC8245856 DOI: 10.1016/j.apsb.2021.03.038] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/07/2021] [Accepted: 03/10/2021] [Indexed: 02/08/2023] Open
Abstract
Obesity and its associated complications are highly related to a current public health crisis around the world. A growing body of evidence has indicated that G-protein coupled bile acid (BA) receptor TGR5 (also known as Gpbar-1) is a potential drug target to treat obesity and associated metabolic disorders. We have identified notoginsenoside Ft1 (Ft1) from Panax notoginseng as an agonist of TGR5 in vitro. However, the pharmacological effects of Ft1 on diet-induced obese (DIO) mice and the underlying mechanisms are still elusive. Here we show that Ft1 (100 mg/100 diet) increased adipose lipolysis, promoted fat browning in inguinal adipose tissue and induced glucagon-like peptide-1 (GLP-1) secretion in the ileum of wild type but not Tgr5 -/- obese mice. In addition, Ft1 elevated serum free and taurine-conjugated bile acids (BAs) by antagonizing Fxr transcriptional activities in the ileum to activate Tgr5 in the adipose tissues. The metabolic benefits of Ft1 were abolished in Cyp27a1 -/- mice which have much lower BA levels. These results identify Ft1 as a single compound with opposite activities on two key BA receptors to alleviate high fat diet-induced obesity and insulin resistance in mice.
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Key Words
- ANOVA, analysis of variance
- AUC, area under the curve
- BAT, brown adipose tissue
- BAs, bile acids
- Bile acids
- DIO, diet-induced obesity
- FGF, fibroblast growth factor
- FXR
- Ft1, notoginsenoside Ft1
- Fxr, nuclear farnesoid X receptor
- GLP-1
- GLP-1, glucagon-like peptide-1
- GTT, glucose tolerance test
- HFD, high fat diet
- ITT, insulin tolerance test
- Insulin resistance
- KO, knockout
- Metabolic disorders
- Notoginsenoside Ft1
- Obesity
- TGR5
- Tgr5, membrane-bound G protein-coupled receptor
- Ucp, uncoupling protein
- Wt, wild-type
- cAMP, adenosine 3′,5′ cyclic monophosphate
- eWAT, epididymal white adipose tissue
- iWAT, inguinal white adipose tissue
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Affiliation(s)
- Lili Ding
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Qiaoling Yang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
- Department of Pharmacy, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 200040, China
| | - Eryun Zhang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Yangmeng Wang
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Siming Sun
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Yingbo Yang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Tong Tian
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhengcai Ju
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Linshan Jiang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Xunjiang Wang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhengtao Wang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Wendong Huang
- Department of Diabetes Complications and Metabolism, Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
- Graduate School of Biological Science, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Li Yang
- Shanghai Key Laboratory of Complex Prescriptions and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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Yoon SJ, Kim SK, Lee NY, Choi YR, Kim HS, Gupta H, Youn GS, Sung H, Shin MJ, Suk KT. Effect of Korean Red Ginseng on metabolic syndrome. J Ginseng Res 2020; 45:380-389. [PMID: 34025131 PMCID: PMC8134847 DOI: 10.1016/j.jgr.2020.11.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/24/2020] [Accepted: 11/02/2020] [Indexed: 12/27/2022] Open
Abstract
Metabolic syndrome (MS) refers to a clustering of at least three of the following medical conditions: high blood pressure, abdominal obesity, hyperglycemia, low high-density lipoprotein level, and high serum triglycerides. MS is related to a wide range of diseases which includes obesity, diabetes, insulin resistance, cardiovascular disease, dyslipidemia, or non-alcoholic fatty liver disease. There remains an ongoing need for improved treatment strategies for MS. The most important risk factors are dietary pattern, genetics, old age, lack of exercise, disrupted biology, medication usage, and excessive alcohol consumption, but pathophysiology of MS has not been completely identified. Korean Red Ginseng (KRG) refers to steamed/dried ginseng, traditionally associated with beneficial effects such as anti-inflammation, anti-fatigue, anti-obesity, anti-oxidant, and anti-cancer effects. KRG has been often used in traditional medicine to treat multiple metabolic conditions. This paper summarizes the effects of KRG in MS and related diseases such as obesity, cardiovascular disease, insulin resistance, diabetes, dyslipidemia, or non-alcoholic fatty liver disease based on experimental research and clinical studies.
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Key Words
- ACC, Acetyl-Coenzyme A carboxylase
- ADP, adenosine diphosphate
- AG, American ginseng extract
- AGE, advanced glycation end product
- ALT, alanine aminotransferase
- AMPK, AMP-activated protein kinase
- AST, aspartate aminotransferase
- Akt, protein kinase B
- BMI, body mass index
- C/EBPα, CCAAT/enhancer-binding protein alpha
- COX-2, cyclooxygenase-2
- CPT, current perception threshold
- CPT-1, carnitine palmitoyl transferase 1
- CRP, C-reactive protein
- CVD, Cardiovascular disease
- DBP, diastolic blood pressure
- DEN, diethyl nitrosamine
- EAT, epididymis adipose tissue
- EF, ejection fraction
- FABP4, fatty acid binding protein 4
- FAS, Fatty acid synthase
- FFA, free fatty acid
- FR, fine root concentration
- FS, fractional shortening
- GBHT, ginseng-plus-Bai-Hu-Tang
- GLUT, glucose transporter type
- GPx, glutathione peroxidase
- GS, ginsenoside
- GST, glutathione S-transferase
- GST-P, glutathione S-transferase placental form
- GTT, glucose tolerance test
- HCC, hepatocellular carcinoma
- HCEF-RG, hypotensive components-enriched fraction of red ginseng
- HDL, high-density lipoprotein
- HFD, High fat diet
- HOMA-IR, homeostasis model assessment of insulin resistance index
- HbA1c, glycosylated hemoglobin
- I.P., intraperitoneal injection
- IL, interleukin
- IR, insulin resistance
- ITT, insulin tolerance test
- Insulin resistance
- KRG, Korean Red Ginseng
- LDL, low-density lipoprotein
- LPL, lipoprotein lipase
- Lex, lower extremities
- MDA, malondialdehyde
- MMP, Matrix metallopeptidases
- MS, Metabolic syndrome
- Metabolic syndrome
- NAFLD, Non-alcoholic fatty liver disease
- NF-кB, nuclear factor kappa-light-chain-enhancer of activated B cells
- NK cell, Natural killer cell
- NMDA-NR1, N-methyl-D-aspartate NR1
- NO, nitric oxide
- NRF1, Nuclear respiratory factor 1
- Non-alcoholic fatty liver disease
- Nrf2, Nuclear factor erythroid 2-related factor 2
- OLETF rat, Otsuka Long-Evans Tokushima fatty rat
- PCG-1α, PPAR-γ coactivator-1α
- PI3K, phosphoinositide 3-kinase
- PPAR, peroxisome proliferator-activated receptors
- PPD, protopanaxadiol
- PPT, protopanaxatriol
- Panax ginseng
- REKRG, Rg3-enriched KRG
- ROS, Reactive oxygen species
- Rg3-KGE, Rg3-enriched KRG extract
- SBP, systolic blood pressure
- SCD, Stearoyl-Coenzyme A desaturase
- SHR, spontaneously hypertensive rat
- SREBP-1C, Sterol regulatory element-binding protein 1
- STAT5, Signal transducer and activator of transcription 5
- STZ, streptozotocin
- TBARS, thiobarbituric acid reactive substances
- TC, total cholesterol
- TG, triglyceride
- TNF, tumor necrosis factor
- UCP, Mitochondrial uncoupling proteins
- VLDL, very low-density lipoprotein
- iNOS, inducible nitric oxide synthase
- t-BHP, tert-butyl hyperoxide
- tGST, total glutathione
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Affiliation(s)
- Sang Jun Yoon
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Seul Ki Kim
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Na Young Lee
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Ye Rin Choi
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Hyeong Seob Kim
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Haripriya Gupta
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Gi Soo Youn
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Hotaik Sung
- School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Min Jea Shin
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
| | - Ki Tae Suk
- Institute for Liver and Digestive Diseases, Hallym University, Chuncheon, Republic of Korea
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Hong KU, Doll MA, Lykoudi A, Salazar-González RA, Habil MR, Walls KM, Bakr AF, Ghare SS, Barve SS, Arteel GE, Hein DW. Acetylator Genotype-Dependent Dyslipidemia in Rats Congenic for N-Acetyltransferase 2. Toxicol Rep 2020; 7:1319-1330. [PMID: 33083237 PMCID: PMC7553889 DOI: 10.1016/j.toxrep.2020.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/14/2020] [Accepted: 09/23/2020] [Indexed: 01/10/2023] Open
Abstract
Recent reports suggest that arylamine N-acetyltransferases (NAT1 and/or NAT2) serve important roles in regulation of energy utility and insulin sensitivity. We investigated the interaction between diet (control vs. high-fat diet) and acetylator phenotype (rapid vs. slow) using previously established congenic rat lines (in F344 background) that exhibit rapid or slow Nat2 (orthologous to human NAT1) acetylator genotypes. Male and female rats of each genotype were fed control or high-fat (Western-style) diet for 26 weeks. We then examined diet- and acetylator genotype-dependent changes in body and liver weights, systemic glucose tolerance, insulin sensitivity, and plasma lipid profile. Male and female rats on the high fat diet weighed approximately 10% more than rats on the control diet and the percentage liver to body weight was consistently higher in rapid than slow acetylator rats. Rapid acetylator rats were more prone to develop dyslipidemia overall (i.e., higher triglyceride; higher LDL; and lower HDL), compared to slow acetylator rats. Total cholesterol (TC)-to-HDL ratios were significantly higher and HDL-to-LDL ratios were significantly lower in rapid acetylator rats. Our data suggest that rats with rapid systemic Nat2 (NAT1 in humans) genotype exhibited higher dyslipidemia conferring risk for metabolic syndrome and cardiovascular dysfunction.
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Affiliation(s)
- Kyung U. Hong
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Mark A. Doll
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Angeliki Lykoudi
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Raúl A. Salazar-González
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Mariam R. Habil
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Kennedy M. Walls
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Alaa F. Bakr
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Smita S. Ghare
- Departments of Medicine and Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Shirish S. Barve
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
- Departments of Medicine and Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Gavin E. Arteel
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
| | - David W. Hein
- Department of Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
- Departments of Medicine and Pharmacology & Toxicology, Center for Hepatobiology & Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
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Diniz AB, Antunes MM, Lacerda VADS, Nakagaki BN, Freitas Lopes MA, Castro-Oliveira HMD, Mattos MS, Mafra K, de Miranda CDM, de Oliveira Costa KM, Lopes ME, Alvarenga DM, Carvalho-Gontijo R, Marchesi SC, Lacerda DR, de Araújo AM, de Carvalho É, David BA, Santos MM, Lima CX, Silva Gomes JA, Minto Fontes Cal TC, de Souza BR, Couto CA, Faria LC, Teixeira Vidigal PV, Matos Ferreira AV, Radhakrishnnan S, Ricci M, Oliveira AG, Rezende RM, Menezes GB. Imaging and immunometabolic phenotyping uncover changes in the hepatic immune response in the early phases of NAFLD. JHEP Rep 2020; 2:100117. [PMID: 32695965 PMCID: PMC7365949 DOI: 10.1016/j.jhepr.2020.100117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/02/2020] [Accepted: 03/26/2020] [Indexed: 12/25/2022] Open
Abstract
Background & Aims The precise determination of non-alcoholic fatty liver disease (NAFLD) onset is challenging. Thus, the initial hepatic responses to fat accumulation, which may be fundamental to our understanding of NAFLD evolution and clinical outcomes, are largely unknown. Herein, we chronologically mapped the immunologic and metabolic changes in the liver during the early stages of fatty liver disease in mice and compared this with human NAFLD samples. Methods Liver biopsies from patients with NAFLD (NAFLD activity score [NAS] 2–3) were collected for gene expression profiling. Mice received a high-fat diet for short periods to mimic initial steatosis and the hepatic immune response was investigated using a combination of confocal intravital imaging, gene expression, cell isolation, flow cytometry and bone marrow transplantation assays. Results We observed major immunologic changes in patients with NAS 2–3 and in mice in the initial stages of NAFLD. In mice, these changes significantly increased mortality rates upon drug-induced liver injury, as well as predisposing mice to bacterial infections. Moreover, deletion of Toll-like receptor 4 in liver cells dampened tolerogenesis, particularly in Kupffer cells, in the initial stages of dietary insult. Conclusion The hepatic immune system acts as a sentinel for early and minor changes in hepatic lipid content, mounting a biphasic response upon dietary insult. Priming of liver immune cells by gut-derived Toll-like receptor 4 ligands plays an important role in liver tolerance in initial phases, but continuous exposure to insults may lead to damage and reduced ability to control infections. Lay summary Fatty liver is a very common form of hepatic disease, leading to millions of cases of cirrhosis every year. Patients are often asymptomatic until becoming very sick. Therefore, it is important that we expand our knowledge of the early stages of disease pathogenesis, to enable early diagnosis. Herein, we show that even in the early stages of fatty liver disease, there are significant alterations in genes involved in the inflammatory response, suggesting that the hepatic immune system is disturbed even following minor and undetectable changes in liver fat content. This could have implications for the diagnosis and clinical management of fatty liver disease. Hepatic immune response is already altered in liver biopsies from patients with mild NAFLD. We designed a novel mouse model to mimic mild NAFLD, enabling the chronological mapping of liver changes. This revealed an increased mortality rate upon secondary liver damage and a window of increased susceptibility to infection. NAFLD diagnosis may be significantly improved by a more profound investigation of changes in hepatic immunology. These data could guide customized nutritional and therapeutic interventions at different stages of NAFLD.
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Key Words
- ALT, alanine aminotransferase
- APAP, acetaminophen
- CFUs, colony forming units
- DCs, dendritic cells
- E. coli, Escherichia coli
- HFD, high-fat diet
- ITT, insulin tolerance test
- KCs, Kupffer cells
- NAFLD
- NAFLD, non-alcoholic fatty liver disease
- NAS, NAFLD activity score
- NPCs, non-parenchymal cells
- SD, standard diet
- TLR4, Toll-like receptor 4
- WT, wild-type
- diet
- immune system
- immunity
- in vivo imaging
- liver
- metabolism
- steatosis
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Affiliation(s)
- Ariane Barros Diniz
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Maísa Mota Antunes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Viviane Aparecida de Souza Lacerda
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Brenda Naemi Nakagaki
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Maria Alice Freitas Lopes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Hortência Maciel de Castro-Oliveira
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Matheus Silvério Mattos
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Kassiana Mafra
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Camila Dutra Moreira de Miranda
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Karen Marques de Oliveira Costa
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Mateus Eustáquio Lopes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Débora Moreira Alvarenga
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | - Sarah Cozzer Marchesi
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | - Alan Moreira de Araújo
- Department of Pharmacodynamics, University of Florida, College of Pharmacy, Gainesville, FL, USA
| | - Érika de Carvalho
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | - Mônica Morais Santos
- Laboratório de Morfologia, Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Cristiano Xavier Lima
- Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | | | - Bruna Roque de Souza
- Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Cláudia Alves Couto
- Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Luciana Costa Faria
- Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | | | | | | | | | | | - Rafael Machado Rezende
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gustavo Batista Menezes
- Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
- Corresponding author. Address: Center for Gastrointestinal Biology, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627 - Belo Horizonte, Minas Gerais, 31270-901, Brazil. Tel./fax: +5531 3409 3015.
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Hu Y, Liu HX, Jena PK, Sheng L, Ali MR, Wan YJY. miR-22 inhibition reduces hepatic steatosis via FGF21 and FGFR1 induction. JHEP Rep 2020; 2:100093. [PMID: 32195457 PMCID: PMC7078383 DOI: 10.1016/j.jhepr.2020.100093] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 01/11/2020] [Accepted: 01/15/2020] [Indexed: 12/12/2022] Open
Abstract
Background & Aims Metabolism supports cell proliferation and growth. Surprisingly, the tumor suppressor miR-22 is induced by metabolic stimulators like bile acids. Thus, this study examines whether miR-22 could be a metabolic silencer. Methods The relationship between miR-22 and the expression of fibroblast growth factor 21 (FGF21) and its receptor FGFR1 was studied in cells and fatty livers obtained from patients and mouse models. We evaluated the effect of an miR-22 inhibitor alone and in combination with obeticholic acid (OCA) for the treatment of steatosis. Results The levels of miR-22 were inversely correlated with those of FGF21, FGFR1, and PGC1α in human and mouse fatty livers, suggesting that hepatic miR-22 acts as a metabolic silencer. Indeed, miR-22 reduced FGFR1 by direct targeting and decreased FGF21 by reducing the recruitment of PPARα and PGC1α to their binding motifs. In contrast, an miR-22 inhibitor increases hepatic FGF21 and FGFR1, leading to AMPK and ERK1/2 activation, which was effective in treating alcoholic steatosis in mouse models. The farnesoid x receptor-agonist OCA induced FGF21 and FGFR1, as well as their inhibitor miR-22. An miR-22 inhibitor and OCA were effective in treating diet-induced steatosis, both alone and in combination. The combined treatment was the most effective at improving insulin sensitivity, releasing glucagon-like peptide 1, and reducing hepatic triglyceride in obese mice. Conclusion The simultaneous induction of miR-22, FGF21 and FGFR1 by metabolic stimulators may maintain FGF21 homeostasis and restrict ERK1/2 activation. Reducing miR-22 enhances hepatic FGF21 and activates AMPK, which could be a novel approach to treat steatosis and insulin resistance. Lay summary This study examines the metabolic role of a tumor suppressor, miR-22, that can be induced by metabolic stimulators such as bile acids. Our novel data revealed that the metabolic silencing effect of miR-22 occurs as a result of reductions in metabolic stimulators, which likely contribute to the development of fatty liver. Consistent with this finding, an miR-22 inhibitor effectively reversed both alcohol- and diet-induced fatty liver; miR-22 inhibition is a promising therapeutic option which could be used in combination with obeticholic acid.
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Key Words
- 3'-UTR, 3' untranslated region
- ALP, alkaline phosphatase
- ALT, alanine aminotransferase
- CD, control diet
- FGF21, fibroblast growth factor 21
- FXR, farnesoid X receptor
- GLP-1, glucagon-like peptide
- HDAC, histone deacetylase
- ITT, insulin tolerance test
- LPS, lipopolysaccharide
- NPCs, non-parenchymal cells
- OCA, obeticholic acid
- PFUs, plaque-forming units
- PGC1α, PPAR-activated receptor-γ coactivator-1α
- PHHs, primary human hepatocytes
- PPREs, peroxisome proliferative-response elements
- RARβ, retinoic acid receptor β
- RT-PCR, reverse transcription PCR
- SIRT1, sirtuin 1
- Steatosis
- WD, Western diet
- alcoholic steatosis
- insulin sensitivity
- metabolic syndrome
- non-alcoholic steatohepatitis
- obeticholic acid
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Affiliation(s)
- Ying Hu
- Department of Pathology and Laboratory Medicine, University of California Davis Health, Sacramento, CA 95817, United States of America
| | - Hui-Xin Liu
- Department of Pathology and Laboratory Medicine, University of California Davis Health, Sacramento, CA 95817, United States of America
| | - Prasant Kuma Jena
- Department of Pathology and Laboratory Medicine, University of California Davis Health, Sacramento, CA 95817, United States of America
| | - Lili Sheng
- Department of Pathology and Laboratory Medicine, University of California Davis Health, Sacramento, CA 95817, United States of America
| | - Mohamed R Ali
- Department of Surgery, University of California Davis Health, Sacramento, CA 95817, United States of America
| | - Yu-Jui Yvonne Wan
- Department of Pathology and Laboratory Medicine, University of California Davis Health, Sacramento, CA 95817, United States of America
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Sun L, Pang Y, Wang X, Wu Q, Liu H, Liu B, Liu G, Ye M, Kong W, Jiang C. Ablation of gut microbiota alleviates obesity-induced hepatic steatosis and glucose intolerance by modulating bile acid metabolism in hamsters. Acta Pharm Sin B 2019; 9:702-710. [PMID: 31384531 PMCID: PMC6664038 DOI: 10.1016/j.apsb.2019.02.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/30/2018] [Accepted: 01/18/2019] [Indexed: 02/07/2023] Open
Abstract
Since metabolic process differs between humans and mice, studies were performed in hamsters, which are generally considered to be a more appropriate animal model for studies of obesity-related metabolic disorders. The modulation of gut microbiota, bile acids and the farnesoid X receptor (FXR) axis is correlated with obesity-induced insulin resistance and hepatic steatosis in mice. However, the interactions among the gut microbiota, bile acids and FXR in metabolic disorders remained largely unexplored in hamsters. In the current study, hamsters fed a 60% high-fat diet (HFD) were administered vehicle or an antibiotic cocktail by gavage twice a week for four weeks. Antibiotic treatment alleviated HFD-induced glucose intolerance, hepatic steatosis and inflammation accompanied with decreased hepatic lipogenesis and elevated thermogenesis in subcutaneous white adipose tissue (sWAT). In the livers of antibiotic-treated hamsters, cytochrome P450 family 7 subfamily B member 1 (CYP7B1) in the alternative bile acid synthesis pathway was upregulated, contributing to a more hydrophilic bile acid profile with increased tauro-β-muricholic acid (TβMCA). The intestinal FXR signaling was suppressed but remained unchanged in the liver. This study is of potential translational significance in determining the role of gut microbiota-mediated bile acid metabolism in modulating diet-induced glucose intolerance and hepatic steatosis in the hamster.
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Key Words
- ALT, alanine amino-transferase
- AST, aspartate transaminase
- AUC, area under curve
- ApoB, apolipoprotein B
- BAs, bile acids
- BSH, bile acid hydrolase
- CA, cholic acid
- CAPE, caffeic acid phenethyl ester
- CDCA, chenodeoxycholic acid
- CETP, cholesterol ester transfer protein
- CYP27A1, cytochrome P450 family 27 subfamily A member 1
- CYP7A1, cytochrome P450 family 7 subfamily A member 1
- CYP7B1
- CYP7B1, cytochrome P450 family 7 subfamily B member 1
- CYP8B1, cytochrome P450 family 8 subfamily B member 1
- DCA, deoxycholic acid
- FGF15/19, fibroblast growth factor 15/19
- FXR
- FXR, farnesoid X receptor
- GCA, glycocholic acid
- GCDCA, glycochenodeoxycholic acid
- GTT, glucose tolerance test
- Gut microbiota
- H&E, hematoxylin and eosin
- HFD, high fat diet
- ITT, insulin tolerance test
- LCA, lithocholic acid
- Metabolic disorders
- NAFLD, non-alcoholic fatty liver disease
- NASH, non-alcoholic steatohepatitis
- PBA/SBA, primary bile acids to secondary bile acids
- T2D, type 2 diabetes
- TC, total cholesterol
- TCA, taurocholic acid
- TG, triglycerides
- TβMCA
- TβMCA, tauro-β-muricholic acid
- UDCA, ursodeoxycholic acid
- UPLC–MS/MS, ultra performance liquid chromatography–tandem mass spectrometry
- VLDL, very low-density lipoprotein
- eWAT, epididymal white adipose tissue
- sWAT, subcutaneous white adipose tissue
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Affiliation(s)
- Lulu Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Yuanyuan Pang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Xuemei Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Qing Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Huiying Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Bo Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - George Liu
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Min Ye
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Wei Kong
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
| | - Changtao Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, and the Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, China
- Corresponding author.
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Sharma RS, Harrison DJ, Kisielewski D, Cassidy DM, McNeilly AD, Gallagher JR, Walsh SV, Honda T, McCrimmon RJ, Dinkova-Kostova AT, Ashford ML, Dillon JF, Hayes JD. Experimental Nonalcoholic Steatohepatitis and Liver Fibrosis Are Ameliorated by Pharmacologic Activation of Nrf2 (NF-E2 p45-Related Factor 2). Cell Mol Gastroenterol Hepatol 2018; 5:367-398. [PMID: 29552625 PMCID: PMC5852394 DOI: 10.1016/j.jcmgh.2017.11.016] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/30/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Nonalcoholic steatohepatitis (NASH) is associated with oxidative stress. We surmised that pharmacologic activation of NF-E2 p45-related factor 2 (Nrf2) using the acetylenic tricyclic bis(cyano enone) TBE-31 would suppress NASH because Nrf2 is a transcriptional master regulator of intracellular redox homeostasis. METHODS Nrf2+/+ and Nrf2-/- C57BL/6 mice were fed a high-fat plus fructose (HFFr) or regular chow diet for 16 weeks or 30 weeks, and then treated for the final 6 weeks, while still being fed the same HFFr or regular chow diets, with either TBE-31 or dimethyl sulfoxide vehicle control. Measures of whole-body glucose homeostasis, histologic assessment of liver, and biochemical and molecular measurements of steatosis, endoplasmic reticulum (ER) stress, inflammation, apoptosis, fibrosis, and oxidative stress were performed in livers from these animals. RESULTS TBE-31 treatment reversed insulin resistance in HFFr-fed wild-type mice, but not in HFFr-fed Nrf2-null mice. TBE-31 treatment of HFFr-fed wild-type mice substantially decreased liver steatosis and expression of lipid synthesis genes, while increasing hepatic expression of fatty acid oxidation and lipoprotein assembly genes. Also, TBE-31 treatment decreased ER stress, expression of inflammation genes, and markers of apoptosis, fibrosis, and oxidative stress in the livers of HFFr-fed wild-type mice. By comparison, TBE-31 did not decrease steatosis, ER stress, lipogenesis, inflammation, fibrosis, or oxidative stress in livers of HFFr-fed Nrf2-null mice. CONCLUSIONS Pharmacologic activation of Nrf2 in mice that had already been rendered obese and insulin resistant reversed insulin resistance, suppressed hepatic steatosis, and mitigated against NASH and liver fibrosis, effects that we principally attribute to inhibition of ER, inflammatory, and oxidative stress.
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Key Words
- ACACA, acetyl-CoA carboxylase alpha
- ACLY, ATP citrate lyase
- ACOT7, acetyl-CoA thioesterase 7
- ACOX2, acetyl-CoA oxidase 2
- ADRP, adipose differentiation-related protein
- AP-1, activator protein 1
- ATF4, activating transcription factor-4
- ATF6, activating transcription factor-6
- ApoB, apolipoprotein B
- BCL-2, B-cell lymphoma
- BIP, binding immunoglobulin protein
- C/EBP, CCAAT/enhancer-binding protein
- CAT, catalase
- CD36, cluster of differentiation 36
- CDDO, 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid
- CES1G, carboxylesterase 1g
- CHOP, C/EBP homologous protein
- COL1A1, collagen, type I, alpha-1
- COX2, cyclooxygenase-2
- CPT1A, carnitine palmitoyltransferase 1a
- ChREBP, carbohydrate-responsive element-binding protein
- DGAT2, diacylglycerol acyltransferase-2
- DMSO, dimethyl sulfoxide
- ER, endoplasmic reticulum
- FASN, fatty acid synthase
- FXR, farnesoid X receptor
- GCLC, glutamate-cysteine ligase catalytic
- GCLM, glutamate-cysteine ligase modifier
- GPX2, glutathione peroxidase-2
- GSH, reduced glutathione
- GSSG, oxidized glutathione
- GSTA4, glutathione S-transferase Alpha-4
- GSTM1, glutathione S-transferase Mu-1
- GTT, glucose tolerance test
- H&E, hematoxylin and eosin
- HF, high-fat
- HF30Fr, high-fat diet with 30% fructose in drinking water
- HF55Fr, high-fat diet with 55% fructose in drinking water
- HFFr, high-fat diet with fructose in drinking water
- HMOX1, heme oxygenase-1
- IKK, IκB kinase
- IRE1α, inositol requiring kinase-1α
- ITT, insulin tolerance test
- IκB, inhibitor of NF-κB
- JNK1, c-Jun N-terminal kinase 1
- Keap1, Kelch-like ECH-associated protein-1
- LXRα, liver X receptor α
- MCD, methionine- and choline-deficient
- MCP-1, monocyte chemotactic protein-1
- MGPAT, mitochondrial glycerol-3-phosphate acetyltransferase
- MPO, myeloperoxidase
- MTTP, microsomal triglyceride transfer protein
- NAFLD, non-alcoholic fatty liver disease
- NAS, NAFLD activity score
- NASH
- NASH, nonalcoholic steatohepatitis
- NF-κB, nuclear factor-κB
- NOS2, nitric oxide synthase-2
- NQO1, NAD(P)H:quinone oxidoreductase 1
- Nrf2
- Nrf2, NF-E2 p45-related factor 2
- PARP, poly ADP ribose polymerase
- PCR, polymerase chain reaction
- PDI, protein disulfide isomerase
- PERK, PRK-like endoplasmic reticulum kinase
- PPARα, peroxisome proliferator-activated receptor α
- PPARγ, peroxisome proliferator-activated receptor γ
- PRDX6, peroxiredoxin 6
- PTGR1, prostaglandin reductase-1
- PTT, pyruvate tolerance test
- RC, regular chow
- SCAD, short-chain acyl-CoA dehydrogenase
- SCD1, stearoyl-CoA desaturase-1
- SFN, sulforaphane
- SHP, small heterodimer partner
- SLC7A11, solute carrier family 7 member 11
- SREBP-1c, sterol regulatory element-binding protein-1c
- TBE-31
- TGFβ, transforming growth factor beta-1
- TNF-α, tumor necrosis factor-α
- TXN1, thioredoxin-1
- TXNRD1, thioredoxin reductase-1
- UPR, unfolded protein response
- XBP1, X-box binding protein-1
- eIf2α, eukaryotic translation initiation factor 2A
- p58IPK, p58 inhibitor of the PKR kinase
- qRT-PCR, quantitative reverse transcriptase PCR
- α-SMA, alpha smooth muscle actin
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Affiliation(s)
- Ritu S. Sharma
- Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - David J. Harrison
- School of Medicine, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Dorothy Kisielewski
- Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Diane M. Cassidy
- Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Alison D. McNeilly
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Jennifer R. Gallagher
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Shaun V. Walsh
- Department of Pathology, Ninewells Hospital and Medical School, Tayside NHS Trust, Dundee, Scotland, United Kingdom
| | - Tadashi Honda
- Department of Chemistry and Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, New York
| | - Rory J. McCrimmon
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Albena T. Dinkova-Kostova
- Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - Michael L.J. Ashford
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - John F. Dillon
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
| | - John D. Hayes
- Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, United Kingdom
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Douris N, Desai BN, Fisher FM, Cisu T, Fowler AJ, Zarebidaki E, Nguyen NLT, Morgan DA, Bartness TJ, Rahmouni K, Flier JS, Maratos-Flier E. Beta-adrenergic receptors are critical for weight loss but not for other metabolic adaptations to the consumption of a ketogenic diet in male mice. Mol Metab 2017; 6:854-62. [PMID: 28752049 DOI: 10.1016/j.molmet.2017.05.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/26/2017] [Accepted: 05/31/2017] [Indexed: 11/21/2022] Open
Abstract
Objective We have previously shown that the consumption of a low-carbohydrate ketogenic diet (KD) by mice leads to a distinct physiologic state associated with weight loss, increased metabolic rate, and improved insulin sensitivity [1]. Furthermore, we identified fibroblast growth factor 21 (FGF21) as a necessary mediator of the changes, as mice lacking FGF21 fed KD gain rather than lose weight [2]. FGF21 activates the sympathetic nervous system (SNS) [3], which is a key regulator of metabolic rate. Thus, we considered that the SNS may play a role in mediating the metabolic adaption to ketosis. Methods To test this hypothesis, we measured the response of mice lacking all three β-adrenergic receptors (β-less mice) to KD feeding. Results In contrast to wild-type (WT) controls, β-less mice gained weight, increased adipose tissue depots mass, and did not increase energy expenditure when consuming KD. Remarkably, despite weight-gain, β-less mice were insulin sensitive. KD-induced changes in hepatic gene expression of β-less mice were similar to those seen in WT controls eating KD. Expression of FGF21 mRNA rose over 60-fold in both WT and β-less mice fed KD, and corresponding circulating FGF21 levels were 12.5 ng/ml in KD-fed wild type controls and 35.5 ng/ml in KD-fed β-less mice. Conclusions The response of β-less mice distinguishes at least two distinct categories of physiologic effects in mice consuming KD. In the liver, KD regulates peroxisome proliferator-activated receptor alpha (PPARα)-dependent pathways through an action of FGF21 independent of the SNS and beta-adrenergic receptors. In sharp contrast, induction of interscapular brown adipose tissue (BAT) and increased energy expenditure absolutely require SNS signals involving action on one or more β-adrenergic receptors. In this way, the key metabolic actions of FGF21 in response to KD have diverse effector mechanisms. Ketogenic diets lead to rapid increases in energy expenditure via increased sympathetic outflow to BAT. Long term the diet leads to weight loss. β-adrenergic receptors mediate these effects; in mice lacking all three β-receptors the effects of the ketogenic diet are not observed. Browning of subcutaneous fat by the diet is partially activated by presumed peripheral mechanisms in the absence of β-adrenergic receptors. Sympathetic nervous system activity not required for improved insulin sensitivity and activation of fatty acid oxidation in the liver.
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Key Words
- BAT, brown adipose tissue
- EE, energy expenditure
- FGF21, fibroblast growth factor 21
- IP, intraperitoneal
- ITT, insulin tolerance test
- IWAT, inguinal white adipose tissue
- KD, ketogenic diet
- Ketogenic diet
- PPARα, peroxisome proliferator-activated receptor alpha
- SEM, standard error of the mean
- SNA, sympathetic nerve activity
- SNS, sympathetic nervous system
- Sympathetic nervous system
- UCP1, uncoupling protein 1
- Weight loss
- β-Adrenergic receptors
- β-less, lacking β1, β2, β3 adrenergic receptors
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Mottillo EP, Desjardins EM, Fritzen AM, Zou VZ, Crane JD, Yabut JM, Kiens B, Erion DM, Lanba A, Granneman JG, Talukdar S, Steinberg GR. FGF21 does not require adipocyte AMP-activated protein kinase (AMPK) or the phosphorylation of acetyl-CoA carboxylase (ACC) to mediate improvements in whole-body glucose homeostasis. Mol Metab 2017; 6:471-481. [PMID: 28580278 PMCID: PMC5444097 DOI: 10.1016/j.molmet.2017.04.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 03/28/2017] [Accepted: 04/02/2017] [Indexed: 01/07/2023] Open
Abstract
Objective Fibroblast growth factor 21 (FGF21) shows great potential for the treatment of obesity and type 2 diabetes, as its long-acting analogue reduces body weight and improves lipid profiles of participants in clinical studies; however, the intracellular mechanisms mediating these effects are poorly understood. AMP-activated protein kinase (AMPK) is an important energy sensor of the cell and a molecular target for anti-diabetic medications. This work examined the role of AMPK in mediating the glucose and lipid-lowering effects of FGF21. Methods Inducible adipocyte AMPK β1β2 knockout mice (iβ1β2AKO) and littermate controls were fed a high fat diet (HFD) and treated with native FGF21 or saline for two weeks. Additionally, HFD-fed mice with knock-in mutations on the AMPK phosphorylation sites of acetyl-CoA carboxylase (ACC)1 and ACC2 (DKI mice) along with wild-type (WT) controls received long-acting FGF21 for two weeks. Results Consistent with previous studies, FGF21 treatment significantly reduced body weight, adiposity, and liver lipids in HFD fed mice. To add, FGF21 improved circulating lipids, glycemic control, and insulin sensitivity. These effects were independent of adipocyte AMPK and were not associated with changes in browning of white (WAT) and brown adipose tissue (BAT). Lastly, we assessed whether FGF21 exerted its effects through the AMPK/ACC axis, which is critical in the therapeutic benefits of the anti-diabetic medication metformin. ACC DKI mice had improved glucose and insulin tolerance and a reduction in body weight, body fat and hepatic steatosis similar to WT mice in response to FGF21 administration. Conclusions These data illustrate that the metabolic improvements upon FGF21 administration are independent of adipocyte AMPK, and do not require the inhibitory action of AMPK on ACC. This is in contrast to the anti-diabetic medication metformin and suggests that the treatment of obesity and diabetes with the combination of FGF21 and AMPK activators merits consideration. FGF21 reduces adiposity and improves insulin resistance in mice fed a high-fat diet. FGF21 improves insulin sensitivity and hepatic steatosis independent of adipocyte AMPK. FGF21 treatment does not elicit an increase in browning of BAT or WAT. In contrast to metformin, FGF21's intracellular mechanism is not through AMPK/ACC. Findings suggest that combination of FGF21 and AMPK activators could be of benefit.
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Key Words
- ACC
- ACC DKI, ACC1-S79A and ACC2-S212A double knock-in
- ACC, acetyl-CoA carboxylase
- AKT, protein kinase B
- AMPK
- AMPK, AMP-activated protein kinase
- Adipocyte
- BAT, brown adipose tissue
- Brown fat
- CNS, central nervous system
- COX, cytochrome c oxidase
- CreERT2, Cre recombinase – estrogen receptor T2
- DAG, diacylglycerol
- Diabetes
- FFA, free fatty acid
- FGF21
- FGF21, fibroblast growth factor 21
- FGFR1c, fibroblast growth factor receptor 1c
- GTT, glucose tolerance test
- H&E, hematoxylin and eosin
- HFD, high fat diet
- ITT, insulin tolerance test
- KLB, beta klotho
- NAFLD, non-alcoholic fatty liver disease
- Obesity
- RER, respiratory exchange ratio
- TAG, triacylglycerol
- UCP1, uncoupling protein 1
- WAT, white adipose tissue
- WT, wildtype
- gWAT, gonadal white adipose tissue
- iWAT, inguinal white adipose tissue
- iβ1β2AKO, inducible AMPK β1β2 adipocyte knockout
- mTORC1, mammalian target of rapamycin
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Affiliation(s)
- Emilio P Mottillo
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
| | - Eric M Desjardins
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
| | - Andreas M Fritzen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Vito Z Zou
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
| | - Justin D Crane
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
| | - Julian M Yabut
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Derek M Erion
- Liver Disease Research, Takeda Pharmaceuticals, 35 Landsdowne Street, Cambridge, MA, 02139, USA
| | - Adhiraj Lanba
- Cardiovascular & Metabolic Diseases, Novartis Institute of Biomedical Research, 250 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | | | - Saswata Talukdar
- Cardiometabolic Diseases, Merck Research Laboratories South San Francisco LLC, 630 Gateway Boulevard, South San Francisco, CA, 94080, USA
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8N 3Z5, Canada
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12
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Douglass JD, Dorfman MD, Fasnacht R, Shaffer LD, Thaler JP. Astrocyte IKKβ/NF-κB signaling is required for diet-induced obesity and hypothalamic inflammation. Mol Metab 2017; 6:366-373. [PMID: 28377875 PMCID: PMC5369266 DOI: 10.1016/j.molmet.2017.01.010] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 01/18/2017] [Accepted: 01/20/2017] [Indexed: 12/18/2022] Open
Abstract
Objective Obesity and high fat diet (HFD) consumption in rodents is associated with hypothalamic inflammation and reactive gliosis. While neuronal inflammation promotes HFD-induced metabolic dysfunction, the role of astrocyte activation in susceptibility to hypothalamic inflammation and diet-induced obesity (DIO) remains uncertain. Methods Metabolic phenotyping, immunohistochemical analyses, and biochemical analyses were performed on HFD-fed mice with a tamoxifen-inducible astrocyte-specific knockout of IKKβ (GfapCreERIkbkbfl/fl, IKKβ-AKO), an essential cofactor of NF-κB-mediated inflammation. Results IKKβ-AKO mice with tamoxifen-induced IKKβ deletion prior to HFD exposure showed equivalent HFD-induced weight gain and glucose intolerance as Ikbkbfl/fl littermate controls. In GfapCreERTdTomato marker mice treated using the same protocol, minimal Cre-mediated recombination was observed in the mediobasal hypothalamus (MBH). By contrast, mice pretreated with 6 weeks of HFD exposure prior to tamoxifen administration showed substantially increased recombination throughout the MBH. Remarkably, this treatment approach protected IKKβ-AKO mice from further weight gain through an immediate reduction of food intake and increase of energy expenditure. Astrocyte IKKβ deletion after HFD exposure—but not before—also reduced glucose intolerance and insulin resistance, likely as a consequence of lower adiposity. Finally, both hypothalamic inflammation and astrocytosis were reduced in HFD-fed IKKβ-AKO mice. Conclusions These data support a requirement for astrocytic inflammatory signaling in HFD-induced hyperphagia and DIO susceptibility that may provide a novel target for obesity therapeutics. The first direct evidence that astrocyte inflammatory activation promotes obesity. GfapCreER mice given tamoxifen show minimal recombination in MBH astrocytes. GfapCreER mice given tamoxifen after 6 wks of HFD have recombination in the MBH. Astrocyte IKKβ deletion with tamoxifen before HFD has no effect on energy balance. Astrocyte IKKβ deletion with tamoxifen given after HFD reduces DIO susceptibility.
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Key Words
- ARC, arcuate nucleus
- Agrp, Agouti-related peptide
- Astrocytes
- Bdnf, brain-derived neurotrophic factor
- Cart, cocaine- and amphetamine-regulated transcript
- Ccl2, C–C motif chemokine ligand 2
- DIO, diet-induced obesity
- DMH, dorsomedial hypothalamus
- Energy homeostasis
- GFAP, glial fibrillary acidic protein
- GSIS, glucose-stimulated insulin secretion
- GTT, glucose tolerance test
- HFD, high-fat diet
- Hypothalamus
- IHC, immunohistochemistry
- IKKβ, inhibitor of kappa B kinase beta
- ITT, insulin tolerance test
- Iba1, ionized calcium binding adaptor molecule 1
- Il, interleukin
- Inflammation
- LPS, lipopolysaccharide
- MBH, mediobasal hypothalamus
- Metabolism
- NF-κB, nuclear factor kappa B
- Npy, neuropeptide Y
- Obesity
- Pomc, proopiomelanocortin
- RER, respiratory exchange ratio
- TMX, tamoxifen
- Tnfa, tumor necrosis factor α
- VMN, ventromedial nucleus
- ir, immunoreactivity
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Affiliation(s)
- J D Douglass
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - M D Dorfman
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - R Fasnacht
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - L D Shaffer
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | - J P Thaler
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, WA 98109, USA.
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13
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Shimazu-Kuwahara S, Harada N, Yamane S, Joo E, Sankoda A, Kieffer TJ, Inagaki N. Attenuated secretion of glucose-dependent insulinotropic polypeptide (GIP) does not alleviate hyperphagic obesity and insulin resistance in ob/ob mice. Mol Metab 2017; 6:288-94. [PMID: 28271035 DOI: 10.1016/j.molmet.2017.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 01/11/2017] [Accepted: 01/16/2017] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVE Glucose-dependent insulinotropic polypeptide (GIP) is released during meals and promotes nutrient uptake and storage. GIP receptor knockout mice are protected from diet induced weight gain and thus GIP antagonists have been proposed as a treatment for obesity. In this study, we assessed the role of GIP in hyperphagia induced obesity and metabolic abnormalities in leptin deficient (Lepob/ob) mice. METHODS We crossbred GIP-GFP knock-in homozygous mice (GIPgfp/gfp) that have complete GIP knockout, and mice heterozygous for the ob mutation (Lepob/+) mice to generate Lepob/+/GIP+/+, Lepob/ob/GIP+/+, and Lepob/ob/GIPgfp/gfp mice. Male animals were weighed weekly and both oral glucose and insulin tolerance testing were performed to assess glucose homeostasis and circulating profiles of GIP and insulin. Body composition was evaluated by computerized tomography (CT) scan and analyses of indirect calorimetry and locomotor activity were performed. RESULTS Postprandial GIP levels were markedly elevated in Lepob/ob/GIP+/+ mice compared to Lepob/+/GIP+/+ controls and were undetectable in Lepob/ob/GIPgfp/gfp mice. Insulin levels were equivalently elevated in both Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice compared to controls at 8 weeks of age but the hyperinsulinemia was marginally reduced in Lepob/ob/GIPgfp/gfp by 21 weeks, in association with amelioration of glucose intolerance. Both Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice remained equivalently insulin resistant. Body weight gain and subcutaneous and visceral fat volume of both Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice were significantly higher than that of Lepob/+/GIP+/+ mice, while no significant differences were seen between Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice. Locomotor activity and energy expenditure were decreased in both Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice compared to control Lepob/+/GIP+/+ mice, while no significant differences were seen between Lepob/ob/GIP+/+ and Lepob/ob/GIPgfp/gfp mice. There was no significant difference in fat oxidation among the three groups. Fat content in liver was significantly lower in Lepob/ob/GIPgfp/gfp compared to Lepob/ob/GIP+/+ mice, while that of control Lepob/+/GIP+/+ mice was the lowest. CONCLUSIONS Our results indicate that GIP knockout does not prevent excess weight gain and metabolic derangement in hyperphagic leptin deficient mice.
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14
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Zanotto TM, Quaresma PGF, Guadagnini D, Weissmann L, Santos AC, Vecina JF, Calisto K, Santos A, Prada PO, Saad MJA. Blocking iNOS and endoplasmic reticulum stress synergistically improves insulin resistance in mice. Mol Metab 2016; 6:206-218. [PMID: 28180062 PMCID: PMC5279911 DOI: 10.1016/j.molmet.2016.12.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/02/2016] [Accepted: 12/12/2016] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Recent data show that iNOS has an essential role in ER stress in obesity. However, whether iNOS is sufficient to account for obesity-induced ER stress and Unfolded Protein Response (UPR) has not yet been investigated. In the present study, we used iNOS knockout mice to investigate whether high-fat diet (HFD) can still induce residual ER stress-associated insulin resistance. METHODS For this purpose, we used the intraperitoneal glucose tolerance test (GTT), euglycemic-hyperinsulinemic clamp, western blotting and qPCR in liver, muscle, and adipose tissue of iNOS KO and control mice on HFD. RESULTS The results of the present study demonstrated that, in HFD fed mice, iNOS-induced alteration in insulin signaling is an essential mechanism of insulin resistance in muscle, suggesting that iNOS may represent an important target that could be blocked in order to improve insulin sensitivity in this tissue. However, in liver and adipose tissue, the insulin resistance induced by HFD was only partially dependent on iNOS, and, even in the presence of genetic or pharmacological blockade of iNOS, a clear ER stress associated with altered insulin signaling remained evident in these tissues. When this ER stress was blocked pharmacologically, insulin signaling was improved, and a complete recovery of glucose tolerance was achieved. CONCLUSIONS Taken together, these results reinforce the tissue-specific regulation of insulin signaling in obesity, with iNOS being sufficient to account for insulin resistance in muscle, but in liver and adipose tissue ER stress and insulin resistance can be induced by both iNOS-dependent and iNOS-independent mechanisms.
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Key Words
- AKT, Protein kinase B
- ATF6, activating transcription factor 6
- Blocking
- ER, endoplasmic reticulum
- Endoplasmic reticulum stress
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- GTT, glucose tolerance test
- HFD, high-fat diet
- IKK, kappa α/β kinase
- IRE1, inositol requiring enzyme 1
- ITT, insulin tolerance test
- Improving
- Insulin resistance
- JNK, c-JunN-terminal kinase
- NO, nitric oxide
- PERK, protein kinase RNA-like ER kinase
- UPR, unfolded protein response
- iNOS
- iNOS, inducible nitric oxide synthase
- qPCR, real time PCR
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Affiliation(s)
- Tamires M Zanotto
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Paula G F Quaresma
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Dioze Guadagnini
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Lais Weissmann
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Andressa C Santos
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Juliana F Vecina
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Kelly Calisto
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Andrey Santos
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Patrícia O Prada
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; School of Applied Sciences, State University of Campinas (UNICAMP), Limeira, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Mario J A Saad
- Department of Internal Medicine, State University of Campinas (UNICAMP), Campinas, SP, Brazil; Department of Medical Clinics, Obesity and Comorbidities Research Center (O.C.R.C.), State University of Campinas (UNICAMP), Campinas, SP, Brazil.
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15
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Schmitt CC, Aranias T, Viel T, Chateau D, Le Gall M, Waligora-Dupriet AJ, Melchior C, Rouxel O, Kapel N, Gourcerol G, Tavitian B, Lehuen A, Brot-Laroche E, Leturque A, Serradas P, Grosfeld A. Intestinal invalidation of the glucose transporter GLUT2 delays tissue distribution of glucose and reveals an unexpected role in gut homeostasis. Mol Metab 2016; 6:61-72. [PMID: 28123938 PMCID: PMC5220280 DOI: 10.1016/j.molmet.2016.10.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 10/20/2016] [Accepted: 10/26/2016] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE Intestinal glucose absorption is orchestrated by specialized glucose transporters such as SGLT1 and GLUT2. However, the role of GLUT2 in the regulation of glucose absorption remains to be fully elucidated. METHODS We wanted to evaluate the role of GLUT2 on glucose absorption and glucose homeostasis after intestinal-specific deletion of GLUT2 in mice (GLUT2ΔIEC mice). RESULTS As anticipated, intestinal GLUT2 deletion provoked glucose malabsorption as visualized by the delay in the distribution of oral sugar in tissues. Consequences of intestinal GLUT2 deletion in GLUT2ΔIEC mice were limiting body weight gain despite normal food intake, improving glucose tolerance, and increasing ketone body production. These features were reminiscent of calorie restriction. Other adaptations to intestinal GLUT2 deletion were reduced microvillus length and altered gut microbiota composition, which was associated with improved inflammatory status. Moreover, a reduced density of glucagon-like peptide-1 (GLP-1) positive cells was compensated by increased GLP-1 content per L-cell, suggesting a preserved enteroendocrine function in GLUT2ΔIEC mice. CONCLUSIONS Intestinal GLUT2 modulates glucose absorption and constitutes a control step for the distribution of dietary sugar to tissues. Consequently, metabolic and gut homeostasis are improved in the absence of functional GLUT2 in the intestine, thus mimicking calorie restriction.
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Key Words
- 2FDG, 2-deoxy-2-[18F]fluoro-d-glucose
- DPP-IV, dipeptidyl-peptidase IV
- GLP-1
- GLP-1, glucagon-like peptide-1
- GLUT1-7, glucose transporter 1–7
- Glucose homeostasis
- IEC, intestinal epithelial cells
- IL, interleukin
- IPGTT, intraperitoneal glucose tolerance test
- ITT, insulin tolerance test
- Intestinal adaptation
- Malabsorption
- Microbiota
- OGTT, oral glucose tolerance test
- PET-CT, Positron Emission Tomography-Computed Tomography
- SGLT1, sodium-glucose transporter 1
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Affiliation(s)
- Charlotte C Schmitt
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Thomas Aranias
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Thomas Viel
- Plateforme imagerie du vivant, Centre de Recherche Cardiovasculaire de Paris, INSERM U970, Université Paris Descartes-Sorbonne Paris cité, Paris, France
| | - Danielle Chateau
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Maude Le Gall
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | | | - Chloé Melchior
- INSERM UMR-1073, Gastroenterology Department, Rouen University Hospital, Rouen, France
| | - Ophélie Rouxel
- INSERM U1016 and CNRS UMR8104, Institut Cochin, Laboratoire d'Excellence INFLAMEX, Paris, France
| | - Nathalie Kapel
- Service de Coprologie Fonctionnelle, Hopital La Pitié Salpêtrière, Paris, France
| | - Guillaume Gourcerol
- INSERM UMR-1073, Gastroenterology Department, Rouen University Hospital, Rouen, France
| | - Bertrand Tavitian
- Plateforme imagerie du vivant, Centre de Recherche Cardiovasculaire de Paris, INSERM U970, Université Paris Descartes-Sorbonne Paris cité, Paris, France
| | - Agnès Lehuen
- INSERM U1016 and CNRS UMR8104, Institut Cochin, Laboratoire d'Excellence INFLAMEX, Paris, France
| | - Edith Brot-Laroche
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Armelle Leturque
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Patricia Serradas
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France
| | - Alexandra Grosfeld
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, UPMC Univ Paris 06, Sorbonne Cités, UPD Univ Paris 05, CNRS, IHU ICAN, Paris, France.
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16
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DiStefano MT, Roth Flach RJ, Senol-Cosar O, Danai LV, Virbasius JV, Nicoloro SM, Straubhaar J, Dagdeviren S, Wabitsch M, Gupta OT, Kim JK, Czech MP. Adipocyte-specific Hypoxia-inducible gene 2 promotes fat deposition and diet-induced insulin resistance. Mol Metab 2016; 5:1149-1161. [PMID: 27900258 PMCID: PMC5123203 DOI: 10.1016/j.molmet.2016.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/15/2016] [Accepted: 09/19/2016] [Indexed: 12/18/2022] Open
Abstract
Objective Adipose tissue relies on lipid droplet (LD) proteins in its role as a lipid-storing endocrine organ that controls whole body metabolism. Hypoxia-inducible Gene 2 (Hig2) is a recently identified LD-associated protein in hepatocytes that promotes hepatic lipid storage, but its role in the adipocyte had not been investigated. Here we tested the hypothesis that Hig2 localization to LDs in adipocytes promotes adipose tissue lipid deposition and systemic glucose homeostasis. Method White and brown adipocyte-deficient (Hig2fl/fl × Adiponection cre+) and selective brown/beige adipocyte-deficient (Hig2fl/fl × Ucp1 cre+) mice were generated to investigate the role of Hig2 in adipose depots. Additionally, we used multiple housing temperatures to investigate the role of active brown/beige adipocytes in this process. Results Hig2 localized to LDs in SGBS cells, a human adipocyte cell strain. Mice with adipocyte-specific Hig2 deficiency in all adipose depots demonstrated reduced visceral adipose tissue weight and increased glucose tolerance. This metabolic effect could be attributed to brown/beige adipocyte-specific Hig2 deficiency since Hig2fl/fl × Ucp1 cre+ mice displayed the same phenotype. Furthermore, when adipocyte-deficient Hig2 mice were moved to thermoneutral conditions in which non-shivering thermogenesis is deactivated, these improvements were abrogated and glucose intolerance ensued. Adipocyte-specific Hig2 deficient animals displayed no detectable changes in adipocyte lipolysis or energy expenditure, suggesting that Hig2 may not mediate these metabolic effects by restraining lipolysis in adipocytes. Conclusions We conclude that Hig2 localizes to LDs in adipocytes, promoting adipose tissue lipid deposition and that its selective deficiency in active brown/beige adipose tissue mediates improved glucose tolerance at 23 °C. Reversal of this phenotype at thermoneutrality in the absence of detectable changes in energy expenditure, adipose mass, or liver triglyceride suggests that Hig2 deficiency triggers a deleterious endocrine or neuroendocrine pathway emanating from brown/beige fat cells. Hig2 localizes to lipid droplets in adipocytes and promotes adipose tissue lipid deposition. Its selective deficiency in active brown/beige adipose tissue mediates improved glucose tolerance at 23 °C. Metabolic improvements are independent of changes in lipolysis.
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Key Words
- Adipocyte
- BAT, brown adipose tissue
- FFA, free fatty acid
- GTT, glucose tolerance test
- HFD, high fat diet
- Hig2, Hypoxia-inducible gene 2
- Hypoxia-inducible gene 2 (Hig2)
- ITT, insulin tolerance test
- LD, lipid droplet
- Lipid droplet
- Lipolysis
- NEFA, non-esterified fatty acid
- Obesity
- RER, respiratory exchange ratio
- SGBS, Simpson-Golabi-Behmel syndrome
- SVF, stromal vascular fraction
- TG, triglyceride
- Ucp1, uncoupling protein 1
- WAT, white adipose tissue
- eWAT, epididymal white adipose tissue
- iWAT, inguinal white adipose tissue
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Affiliation(s)
- Marina T DiStefano
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Rachel J Roth Flach
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ozlem Senol-Cosar
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Laura V Danai
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Joseph V Virbasius
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sarah M Nicoloro
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Juerg Straubhaar
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sezin Dagdeviren
- From the Program in Molecular Medicine and the Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Martin Wabitsch
- From the Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University Medical Center Ulm, Ulm 89075, Germany
| | - Olga T Gupta
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jason K Kim
- From the Program in Molecular Medicine and the Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Michael P Czech
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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Ghoshal S, Zhu Q, Asteian A, Lin H, Xu H, Ernst G, Barrow JC, Xu B, Cameron MD, Kamenecka TM, Chakraborty A. TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway. Mol Metab 2016; 5:903-917. [PMID: 27689003 PMCID: PMC5034689 DOI: 10.1016/j.molmet.2016.08.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/10/2016] [Accepted: 08/15/2016] [Indexed: 12/30/2022] Open
Abstract
Objective Obesity and type 2 diabetes (T2D) lead to various life-threatening diseases such as coronary heart disease, stroke, osteoarthritis, asthma, and neurodegeneration. Therefore, extensive research is ongoing to identify novel pathways that can be targeted in obesity/T2D. Deletion of the inositol pyrophosphate (5-IP7) biosynthetic enzyme, inositol hexakisphosphate kinase-1 (IP6K1), protects mice from high fat diet (HFD) induced obesity (DIO) and insulin resistance. Yet, whether this pathway is a valid pharmacologic target in obesity/T2D is not known. Here, we demonstrate that TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine], a pan-IP6K inhibitor, has strong anti-obesity and anti-diabetic effects in DIO mice. Methods Q-NMR, GTT, ITT, food intake, energy expenditure, QRT-PCR, ELISA, histology, and immunoblot studies were conducted in short (2.5-week)- and long (10-week)-term TNP treated DIO C57/BL6 WT and IP6K1-KO mice, under various diet and temperature conditions. Results TNP, when injected at the onset of HFD-feeding, decelerates initiation of DIO and insulin resistance. Moreover, TNP facilitates weight loss and restores metabolic parameters, when given to DIO mice. However, TNP does not reduce weight gain in HFD-fed IP6K1-KO mice. TNP specifically enhances insulin sensitivity in DIO mice via Akt activation. TNP decelerates weight gain primarily by enhancing thermogenic energy expenditure in the adipose tissue. Accordingly, TNP's effect on body weight is partly abolished whereas its impact on glucose homeostasis is preserved at thermoneutral temperature. Conclusion Pharmacologic inhibition of the inositol pyrophosphate pathway has strong therapeutic potential in obesity, T2D, and other metabolic diseases. Pharmacologic inhibition of IP6K by TNP, at the onset of high fat feeding, decelerates initiation of DIO and insulin resistance in mice. TNP, when treated to DIO mice, promotes weight loss and restores metabolic homeostasis. TNP does not reduce high fat diet induced weight gain in IP6K1-KO mice. TNP promotes insulin sensitivity by stimulating Akt activity, whereas it reduces body weight primarily by enhancing thermogenic energy expenditure. Long-term TNP treatment does not display deleterious side effects.
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Key Words
- 5-IP7, diphosphoinositol pentakisphosphate
- ALT, alanine aminotransferase
- AST, aspartate transaminase
- AUC, area under curve
- Akt
- BAT, brown adipose tissue
- CD, chow-diet
- CPT1a, carnitine palmitoyltransferase I
- Cidea, cell death activator-A
- DIO, diet-induced obesity
- Diabetes
- EE, energy expenditure
- EWAT, epididymal adipose tissue
- Energy expenditure
- GSK3, glycogen synthase kinase
- GTT, glucose tolerance test
- H&E, hematoxylin and eosin
- HFD, high-fat diet
- HPLC, high performance liquid chromatography
- IP6K
- IP6K, Inositol hexakisphosphate kinase
- IP6K1-KO, IP6K1 knockout
- ITT, insulin tolerance test
- IWAT, inguinal adipose tissue
- Inositol pyrophosphate
- Obesity
- PCR, polymerase chain reaction
- PGC1α, PPAR coactivator 1 alpha
- PKA, protein kinase A
- PPARγ, peroxisome proliferator-activated receptor gamma
- PRDM16, PR domain containing 16
- Pro-TNP, TNP treatment for protection against DIO
- Q-NMR, quantitative nuclear magnetic resonance
- QRT-PCR, quantitative reverse transcription polymerase chain reaction
- RER, Respiratory exchange ratio
- RWAT, retroperitoneal adipose tissue
- Rev-TNP, long-term TNP treatment for reversal of DIO
- RevT-TNP, Long-term TNP treatment for reversal of DIO at thermoneutral temperature
- S473, serine 473
- S9, serine 9
- SREV-TNP, short-term TNP treatment for reversal of DIO
- T2D, type-2 diabetes
- T308, threonine 308
- TNP, [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine]
- UCP-1/3, uncoupling protein 1/3
- VO2, volume of oxygen consumption
- WAT, white adipose tissue
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Affiliation(s)
- Sarbani Ghoshal
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Qingzhang Zhu
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Alice Asteian
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hua Lin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Haifei Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Glen Ernst
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - James C Barrow
- Drug Discovery Division, Lieber Institute for Brain Development, Baltimore, MD 21205, USA
| | - Baoji Xu
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Michael D Cameron
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Theodore M Kamenecka
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Anutosh Chakraborty
- Department of Metabolism and Aging, The Scripps Research Institute, Jupiter, FL 33458, USA.
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McCommis KS, Hodges WT, Bricker DK, Wisidagama DR, Compan V, Remedi MS, Thummel CS, Finck BN. An ancestral role for the mitochondrial pyruvate carrier in glucose-stimulated insulin secretion. Mol Metab 2016; 5:602-614. [PMID: 27656398 PMCID: PMC5021712 DOI: 10.1016/j.molmet.2016.06.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 06/24/2016] [Accepted: 06/30/2016] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE Transport of pyruvate into the mitochondrial matrix by the Mitochondrial Pyruvate Carrier (MPC) is an important and rate-limiting step in its metabolism. In pancreatic β-cells, mitochondrial pyruvate metabolism is thought to be important for glucose sensing and glucose-stimulated insulin secretion. METHODS To evaluate the role that the MPC plays in maintaining systemic glucose homeostasis, we used genetically-engineered Drosophila and mice with loss of MPC activity in insulin-producing cells. RESULTS In both species, MPC deficiency results in elevated blood sugar concentrations and glucose intolerance accompanied by impaired glucose-stimulated insulin secretion. In mouse islets, β-cell MPC-deficiency resulted in decreased respiration with glucose, ATP-sensitive potassium (KATP) channel hyperactivity, and impaired insulin release. Moreover, treatment of pancreas-specific MPC knockout mice with glibenclamide, a sulfonylurea KATP channel inhibitor, improved defects in islet insulin secretion and abnormalities in glucose homeostasis in vivo. Finally, using a recently-developed biosensor for MPC activity, we show that the MPC is rapidly stimulated by glucose treatment in INS-1 insulinoma cells suggesting that glucose sensing is coupled to mitochondrial pyruvate carrier activity. CONCLUSIONS Altogether, these studies suggest that the MPC plays an important and ancestral role in insulin-secreting cells in mediating glucose sensing, regulating insulin secretion, and controlling systemic glycemia.
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Key Words
- DILP2, Drosophila insulin-like peptide 2
- Diabetes
- Drosophila
- GSIS, glucose-stimulated insulin secretion
- GTT, glucose tolerance test
- IMM, inner mitochondrial membrane
- IPCs, Insulin-producing Cells
- ITT, insulin tolerance test
- Insulin
- MPC1 and MPC2, Mitochondrial Pyruvate Carrier 1 and 2
- Mitochondria
- OCR, oxygen consumption rates
- Pdx1, pancreatic and duodenal homeobox 1
- Pyruvate
- RESPYR, REporter Sensitive to PYRuvate
- Stimulus-coupled secretion
- β-Cell
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Affiliation(s)
- Kyle S McCommis
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Wesley T Hodges
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daniel K Bricker
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Dona R Wisidagama
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Vincent Compan
- Institute of Functional Genomics, Labex ICST; INSERM U1191, CNRS UMR5203; University of Montpellier, Montpellier, France
| | - Maria S Remedi
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carl S Thummel
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Bowman TA, O'Keeffe KR, D'Aquila T, Yan QW, Griffin JD, Killion EA, Salter DM, Mashek DG, Buhman KK, Greenberg AS. Acyl CoA synthetase 5 (ACSL5) ablation in mice increases energy expenditure and insulin sensitivity and delays fat absorption. Mol Metab 2016; 5:210-220. [PMID: 26977393 PMCID: PMC4770262 DOI: 10.1016/j.molmet.2016.01.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/22/2015] [Accepted: 01/03/2016] [Indexed: 11/10/2022] Open
Abstract
Objective The family of acyl-CoA synthetase enzymes (ACSL) activates fatty acids within cells to generate long chain fatty acyl CoA (FACoA). The differing metabolic fates of FACoAs such as incorporation into neutral lipids, phospholipids, and oxidation pathways are differentially regulated by the ACSL isoforms. In vitro studies have suggested a role for ACSL5 in triglyceride synthesis; however, we have limited understanding of the in vivo actions of this ACSL isoform. Methods To elucidate the in vivo actions of ACSL5 we generated a line of mice in which ACSL5 expression was ablated in all tissues (ACSL5−/−). Results Ablation of ACSL5 reduced ACSL activity by ∼80% in jejunal mucosa, ∼50% in liver, and ∼37% in brown adipose tissue lysates. Body composition studies revealed that ACSL5−/−, as compared to control ACSL5loxP/loxP, mice had significantly reduced fat mass and adipose fat pad weights. Indirect calorimetry studies demonstrated that ACSL5−/− had increased metabolic rates, and in the dark phase, increased respiratory quotient. In ACSL5−/− mice, fasting glucose and serum triglyceride were reduced; and insulin sensitivity was improved during an insulin tolerance test. Both hepatic mRNA (∼16-fold) and serum levels of fibroblast growth factor 21 (FGF21) (∼13-fold) were increased in ACSL5−/− as compared to ACSL5loxP/loxP. Consistent with increased FGF21 serum levels, uncoupling protein-1 gene (Ucp1) and PPAR-gamma coactivator 1-alpha gene (Pgc1α) transcript levels were increased in gonadal adipose tissue. To further evaluate ACSL5 function in intestine, mice were gavaged with an olive oil bolus; and the rate of triglyceride appearance in serum was found to be delayed in ACSL5−/− mice as compared to control mice. Conclusions In summary, ACSL5−/− mice have increased hepatic and serum FGF21 levels, reduced adiposity, improved insulin sensitivity, increased energy expenditure and delayed triglyceride absorption. These studies suggest that ACSL5 is an important regulator of whole-body energy metabolism and ablation of ACSL5 may antagonize the development of obesity and insulin resistance. Role of acyl CoA synthetase 5 (ACSL5) in systemic metabolism was studied in an ACSL5 deficient mouse. ACSL5 deficiency reduced total ACSL activity in liver, intestine, and brown adipose tissue. ACSL5 deficient mice had increased hepatic and circulating FGF21 expression and energy expenditure. ACSL5 deficient mice demonstrated delayed triglyceride absorption.
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Key Words
- ACSL
- ACSL, long-chain acyl-CoA synthetase
- ACSL5−/−, mice with global ablation of ACSL5
- AUC, area under the curve
- Acyl-CoA
- Dietary fat absorption
- ES, embryonic stem
- FGF21
- FGF21, fibroblast growth factor 21
- ITT, insulin tolerance test
- Intestine
- Liver
- NAFLD, non-alcoholic fatty liver disease
- PGC1α, PPAR-gamma coactivator 1α
- PPAR, peroxisome proliferator activated receptor
- RER, respiratory exchange ratio
- SDS, sodium dodecyl sulfate
- SREBP1c, steroid response element binding protein-1c
- T2DM, type2 diabetes
- UCP1, uncoupling protein-1
- VLDL, very low density lipoprotein
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Affiliation(s)
- Thomas A Bowman
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - Kayleigh R O'Keeffe
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - Theresa D'Aquila
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA.
| | - Qing Wu Yan
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - John D Griffin
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - Elizabeth A Killion
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - Deanna M Salter
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
| | - Douglas G Mashek
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN, USA.
| | - Andrew S Greenberg
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA.
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Iizuka Y, Kim H, Nakasatomi M, Izawa T, Hirako S, Matsumoto A. Fish oil prevents excessive accumulation of subcutaneous fat caused by an adverse effect of pioglitazone treatment and positively changes adipocytes in KK mice. Toxicol Rep 2016; 3:4-14. [PMID: 28959521 DOI: 10.1016/j.toxrep.2015.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/07/2015] [Accepted: 11/09/2015] [Indexed: 12/17/2022] Open
Abstract
Pioglitazone, a thiazolidinedione (TZD), is widely used as an insulin sensitizer in the treatment of type 2 diabetes. However, body weight gain is frequently observed in TZD-treated patients. Fish oil improves lipid metabolism dysfunction and obesity. In this study, we demonstrated suppression of body weight gain in response to pioglitazone administration by combination therapy of pioglitazone and fish oil in type 2 diabetic KK mice. Male KK mice were fed experimental diets for 8 weeks. In safflower oil (SO), safflower oil/low-dose pioglitazone (S/PL), and safflower oil/high-dose pioglitazone (S/PH) diets, 20% of calories were provided by safflower oil containing 0%, 0.006%, or 0.012% (wt/wt) pioglitazone, respectively. In fish oil (FO), fish oil/low-dose pioglitazone (F/PL), and fish oil/high-dose pioglitazone (F/PH) diets, 20% of calories were provided by a mixture of fish oil and safflower oil. Increased body weight and subcutaneous fat mass were observed in the S/PL and S/PH groups; however, diets containing fish oil were found to ameliorate these changes. Hepatic mRNA levels of lipogenic enzymes were significantly decreased in fish oil-fed groups. These findings demonstrate that the combination of pioglitazone and fish oil decreases subcutaneous fat accumulation, ameliorating pioglitazone-induced body weight gain, through fish oil-mediated inhibition of hepatic de novo lipogenesis.
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Key Words
- ACC, acetyl-CoA carboxylase
- AOX, acyl-CoA oxidase
- ATM, adipose tissue macrophage
- AUC, area under the curve
- Adverse effect
- BAT, brown adipose tissue
- CPT-1, carnitine palmitoyl transferase 1
- CT, computed tomography
- DHA, docosahexaenoic acid
- ELISA, enzyme-linked immunosorbent assay
- EPA, eicosapentaenoic acid
- FAS, fatty acid synthase
- FFA, free fatty acid
- Fish oil
- G6pase, glucose-6-phosphatase
- GPAT, glycerol-3-phosphate acyltransferase
- H&E, hematoxylin and eosin
- HDL-C, high-density lipoprotein cholesterol
- HOMA-IR, homeostasis model assessment of insulin resistance
- IR, insulin resistance
- ITT, insulin tolerance test
- Insig-1, insulin-induced gene 1
- MCAD, medium-chain acyl-CoA dehydrogenase
- MCP-1, monocyte chemoattractant protein-1
- OGTT, oral glucose tolerance test
- PEPCK, phosphoenolpyruvate carboxykinase
- PPARα, peroxisome proliferator-activated receptor alpha
- PPARγ, peroxisome proliferator-activated receptor gamma
- Pioglitazone
- RT-PCR, real-time polymerase chain reaction
- SCD-1, stearoyl-CoA desaturase 1
- SREBP, sterol regulatory element-binding protein
- TLR-4, toll-like receptor-4
- TNF-α, tumor necrosis factor-α
- TZD, thiazolidinedione
- UCP-2, uncoupling protein 2
- VLDL, very low-density lipoprotein
- WAT, white adipose tissue
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Nixon M, Stewart-Fitzgibbon R, Fu J, Akhmedov D, Rajendran K, Mendoza-Rodriguez MG, Rivera-Molina YA, Gibson M, Berglund ED, Justice NJ, Berdeaux R. Skeletal muscle salt inducible kinase 1 promotes insulin resistance in obesity. Mol Metab 2015; 5:34-46. [PMID: 26844205 PMCID: PMC4703802 DOI: 10.1016/j.molmet.2015.10.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 10/19/2015] [Accepted: 10/22/2015] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE Insulin resistance causes type 2 diabetes mellitus and hyperglycemia due to excessive hepatic glucose production and inadequate peripheral glucose uptake. Our objectives were to test the hypothesis that the proposed CREB/CRTC2 inhibitor salt inducible kinase 1 (SIK1) contributes to whole body glucose homeostasis in vivo by regulating hepatic transcription of gluconeogenic genes and also to identify novel SIK1 actions on glucose metabolism. METHODS We created conditional (floxed) SIK1-knockout mice and studied glucose metabolism in animals with global, liver, adipose or skeletal muscle Sik1 deletion. We examined cAMP-dependent regulation of SIK1 and the consequences of SIK1 depletion on primary mouse hepatocytes. We probed metabolic phenotypes in tissue-specific SIK1 knockout mice fed high fat diet through hyperinsulinemic-euglycemic clamps and biochemical analysis of insulin signaling. RESULTS SIK1 knockout mice are viable and largely normoglycemic on chow diet. On high fat diet, global SIK1 knockout animals are strikingly protected from glucose intolerance, with both increased plasma insulin and enhanced peripheral insulin sensitivity. Surprisingly, liver SIK1 is not required for regulation of CRTC2 and gluconeogenesis, despite contributions of SIK1 to hepatocyte CRTC2 and gluconeogenesis regulation ex vivo. Sik1 mRNA accumulates in skeletal muscle of obese high fat diet-fed mice, and knockout of SIK1 in skeletal muscle, but not liver or adipose tissue, improves insulin sensitivity and muscle glucose uptake on high fat diet. CONCLUSIONS SIK1 is dispensable for glycemic control on chow diet. SIK1 promotes insulin resistance on high fat diet by a cell-autonomous mechanism in skeletal muscle. Our study establishes SIK1 as a promising therapeutic target to improve skeletal muscle insulin sensitivity in obese individuals without deleterious effects on hepatic glucose production.
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Key Words
- AKT, protein kinase B
- AMPK, AMP-activated protein kinase
- BAT, brown adipose tissue
- CHX, cycloheximide
- CREB
- CREB, cAMP response element-binding protein
- CRTC
- CRTC, CREB regulated transcription coactivator
- EndoRa, endogenous rate of glucose appearance
- FGF21, fibroblast growth factor 21
- FOXO1, forkhead box protein O1
- FSK, forskolin
- G6pase, glucose 6-phosphatase
- GDR, glucose disposal rate
- GIR, glucose infusion rate
- GTT, glucose tolerance test
- Glgn, glucagon
- Gluconeogenesis
- Glut, glucose transporter
- HDAC, histone deacetylase
- HFD, high fat diet
- HSP, heat shock protein
- IBMX, 3-isobutyl-1-methylxantine
- ITT, insulin tolerance test
- Insulin resistance
- PTT, pyruvate tolerance test
- Pepck, phosphoenolpyruvate carboxykinase
- Pgc, peroxisome proliferator-activated receptor gamma coactivator
- SIK, salt inducible kinase
- SIK1
- Salt inducible kinase
- WAT, white adipose tissue
- cAMP, cyclic adenosine monophosphate
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Affiliation(s)
- Mark Nixon
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Randi Stewart-Fitzgibbon
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA; Program in Cell and Regulatory Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston TX 77030, USA
| | - Jingqi Fu
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Dmitry Akhmedov
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Kavitha Rajendran
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Maria G Mendoza-Rodriguez
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Yisel A Rivera-Molina
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Micah Gibson
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Eric D Berglund
- Advanced Imaging Research Center and Department of Pharmacology, University of Texas Southwestern Medical School, USA
| | - Nicholas J Justice
- Institute of Molecular Medicine Center for Metabolic and Degenerative Diseases, University of Texas Health Science Center, Houston, TX 77030, USA; Program in Cell and Regulatory Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston TX 77030, USA
| | - Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA; Institute of Molecular Medicine Center for Metabolic and Degenerative Diseases, University of Texas Health Science Center, Houston, TX 77030, USA; Program in Cell and Regulatory Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston TX 77030, USA
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Üner A, Gonçalves GH, Li W, Porceban M, Caron N, Schönke M, Delpire E, Sakimura K, Bjørbæk C. The role of GluN2A and GluN2B NMDA receptor subunits in AgRP and POMC neurons on body weight and glucose homeostasis. Mol Metab 2015; 4:678-91. [PMID: 26500840 PMCID: PMC4588453 DOI: 10.1016/j.molmet.2015.06.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/15/2015] [Accepted: 06/19/2015] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Hypothalamic agouti-related peptide (AgRP) and pro-opiomelanocortin (POMC) expressing neurons play critical roles in control of energy balance. Glutamatergic input via n-methyl-d-aspartate receptors (NMDARs) is pivotal for regulation of neuronal activity and is required in AgRP neurons for normal body weight homeostasis. NMDARs typically consist of the obligatory GluN1 subunit and different GluN2 subunits, the latter exerting crucial differential effects on channel activity and neuronal function. Currently, the role of specific GluN2 subunits in AgRP and POMC neurons on whole body energy and glucose balance is unknown. METHODS We used the cre-lox system to genetically delete GluN2A or GluN2B only from AgRP or POMC neurons in mice. Mice were then subjected to metabolic analyses and assessment of AgRP and POMC neuronal function through morphological studies. RESULTS We show that loss of GluN2B from AgRP neurons reduces body weight, fat mass, and food intake, whereas GluN2B in POMC neurons is not required for normal energy balance control. GluN2A subunits in either AgRP or POMC neurons are not required for regulation of body weight. Deletion of GluN2B reduces the number of AgRP neurons and decreases their dendritic length. In addition, loss of GluN2B in AgRP neurons of the morbidly obese and severely diabetic leptin-deficient Lep (ob/ob) mice does not affect body weight and food intake but, remarkably, leads to full correction of hyperglycemia. Lep (ob/ob) mice lacking GluN2B in AgRP neurons are also more sensitive to leptin's anti-obesity actions. CONCLUSIONS GluN2B-containing NMDA receptors in AgRP neurons play a critical role in central control of body weight homeostasis and blood glucose balance via mechanisms that likely involve regulation of AgRP neuronal survival and structure, and modulation of hypothalamic leptin action.
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Key Words
- AAC, area above the curve
- AMPARs, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors
- ANCOVA, analysis of covariance
- ANOVA, analysis of variance
- AUC, area under the curve
- AgRP
- AgRP, agouti-related peptide
- CNS, central nervous system
- DAB, 3,3′-diaminobenzidine
- DIO, diet-induced obesity
- DREADD, Designer Receptor Exclusively Activated by Dedigner Drugs
- EPSCs, excitatory post-synaptic synaptic currents
- GABA, gamma-aminobutyric acid
- GTT, glucose tolerance test
- GluN2B
- Glycemia
- HFD, high-fat diet
- HSD, honestly significant difference
- ITT, insulin tolerance test
- KO, knockout
- LTD, long-term depression
- LTP, long-term potentiation
- Lepob/ob mice, obese leptin-deficient mice
- Leptin
- Metabolism
- NMDAR
- NMDARs, N-methyl-d-aspartate receptors
- PBS, phosphate-buffered saline
- POMC, pro-opiomelanocortin
- PVN, paraventricular nucleus
- RT, room temperature
- hrGFP, humanized renilla GFP
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Affiliation(s)
- Aykut Üner
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Gabriel H.M. Gonçalves
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Wenjing Li
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Matheus Porceban
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Nicole Caron
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Milena Schönke
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical School, Nashville, TN 37232, USA
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Christian Bjørbæk
- Department of Medicine, Division of Endocrinology and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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Liu PS, Lin YW, Burton FH, Wei LN. Injecting engineered anti-inflammatory macrophages therapeutically induces white adipose tissue browning and improves diet-induced insulin resistance. Adipocyte 2015; 4:123-8. [PMID: 26167415 DOI: 10.4161/21623945.2014.981438] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/03/2014] [Accepted: 10/23/2014] [Indexed: 12/17/2022] Open
Abstract
We recently exploited a transgenic approach to coerce macrophage anti-inflammatory M2 polarization in vivo by lowering Receptor Interacting Protein 140 (RIP140) level in macrophages (mφRIP140KD), which induced browning of white adipose tissue (WAT). In vitro, conditioned medium from cultured adipose tissue macrophages (ATMs) of mφRIP140KD mice could trigger preadipocytes' differentiation into beige cells. Here we describe a cell therapy for treating high fat diet (HFD)-induced insulin resistance (IR). Injecting M2 ATMs retrieved from the WAT of mφRIP140KD mice into HFD-fed obese adult wild-type mice effectively triggers their WAT browning, reduces their pro-inflammatory responses, and improves their insulin sensitivity. These data provide a proof-of-concept that delivering engineered anti-inflammatory macrophages can trigger white fat browning, stimulate whole-body thermogenesis, and reduce obesity-associated IR.
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Key Words
- (v)WAT, (visceral) white adipose tissue
- ATM(s), adipose tissue macrophage(s)
- BAT, brown adipose tissue
- FFA, free fatty acid
- GTT, glucose tolerance test
- HFD
- HFD, high-fat diet
- IL4, Interleukin 4
- IR, insulin resistance
- ITT, insulin tolerance test
- KD, knockdown mice
- M2 ATM
- ND, normal diet
- PBS, phosphate-buffered saline
- RIP140
- RIP140, Receptor Interacting Protein 140
- SVF, stromal vascular fraction
- TG, triglyceride
- WT, wild-type mice
- beige cells
- browning
- insulin resistance
- macrophages
- mφRIP140KD, macrophage-specific RIP140 knockdown mutation
- obesity
- preadipocyte differentiation
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Krüger J, Brachs S, Trappiel M, Kintscher U, Meyborg H, Wellnhofer E, Thöne-Reineke C, Stawowy P, Östman A, Birkenfeld AL, Böhmer FD, Kappert K. Enhanced insulin signaling in density-enhanced phosphatase-1 (DEP-1) knockout mice. Mol Metab 2015; 4:325-36. [PMID: 25830095 PMCID: PMC4354926 DOI: 10.1016/j.molmet.2015.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 01/30/2015] [Accepted: 02/04/2015] [Indexed: 01/06/2023] Open
Abstract
Objective Insulin resistance can be triggered by enhanced dephosphorylation of the insulin receptor or downstream components in the insulin signaling cascade through protein tyrosine phosphatases (PTPs). Downregulating density-enhanced phosphatase-1 (DEP-1) resulted in an improved metabolic status in previous analyses. This phenotype was primarily caused by hepatic DEP-1 reduction. Methods Here we further elucidated the role of DEP-1 in glucose homeostasis by employing a conventional knockout model to explore the specific contribution of DEP-1 in metabolic tissues. Ptprj−/− (DEP-1 deficient) and wild-type C57BL/6 mice were fed a low-fat or high-fat diet. Metabolic phenotyping was combined with analyses of phosphorylation patterns of insulin signaling components. Additionally, experiments with skeletal muscle cells and muscle tissue were performed to assess the role of DEP-1 for glucose uptake. Results High-fat diet fed-Ptprj−/− mice displayed enhanced insulin sensitivity and improved glucose tolerance. Furthermore, leptin levels and blood pressure were reduced in Ptprj−/− mice. DEP-1 deficiency resulted in increased phosphorylation of components of the insulin signaling cascade in liver, skeletal muscle and adipose tissue after insulin challenge. The beneficial effect on glucose homeostasis in vivo was corroborated by increased glucose uptake in skeletal muscle cells in which DEP-1 was downregulated, and in skeletal muscle of Ptprj−/− mice. Conclusion Together, these data establish DEP-1 as novel negative regulator of insulin signaling.
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Key Words
- DEP-1, density-enhanced phosphatase-1
- Density-enhanced phosphatase-1
- GTT, glucose tolerance test
- Glucose homeostasis
- HFD, high-fat diet
- IL-6, interleukin 6
- IR, insulin receptor
- ITT, insulin tolerance test
- Insulin resistance
- Insulin signaling
- KO, knockout
- LFD, low-fat diet
- MCP-1, monocyte chemotactic protein-1
- PTP, protein tyrosine phosphatase
- Phosphorylation
- RER, respiratory exchange ratio
- RTK, receptor tyrosine kinase
- WT, wild-type
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Affiliation(s)
- Janine Krüger
- Center for Cardiovascular Research/CCR, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Sebastian Brachs
- Center for Cardiovascular Research/CCR, Department of Endocrinology, Diabetes and Nutrition, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Manuela Trappiel
- Center for Cardiovascular Research/CCR, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Ulrich Kintscher
- Center for Cardiovascular Research/CCR, Institute of Pharmacology, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Heike Meyborg
- Department of Medicine/Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Ernst Wellnhofer
- Department of Medicine/Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Christa Thöne-Reineke
- Center for Cardiovascular Research/CCR, Department of Experimental Medicine, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Philipp Stawowy
- Department of Medicine/Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Arne Östman
- Cancer Center Karolinska, R8:03, Department of Oncology-Pathology, Karolinska Institutet, 171 76 Stockholm, Sweden
| | - Andreas L Birkenfeld
- Center for Cardiovascular Research/CCR, Department of Endocrinology, Diabetes and Nutrition, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
| | - Frank D Böhmer
- Center for Molecular Biomedicine, Institute of Molecular Cell Biology, Universitätsklinikum Jena, Hans-Knöll-Str. 2, 07745 Jena, Germany
| | - Kai Kappert
- Center for Cardiovascular Research/CCR, Institute of Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Hessische Str. 3-4, 10115 Berlin, Charité - Universitätsmedizin Berlin, Germany
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Zampieri TT, Ramos-Lobo AM, Furigo IC, Pedroso JAB, Buonfiglio DC, Donato J. SOCS3 deficiency in leptin receptor-expressing cells mitigates the development of pregnancy-induced metabolic changes. Mol Metab 2014; 4:237-45. [PMID: 25737950 PMCID: PMC4338315 DOI: 10.1016/j.molmet.2014.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 12/08/2014] [Accepted: 12/12/2014] [Indexed: 12/25/2022] Open
Abstract
Objective During pregnancy, women normally increase their food intake and body fat mass, and exhibit insulin resistance. However, an increasing number of women are developing metabolic imbalances during pregnancy, including excessive gestational weight gain and gestational diabetes mellitus. Despite the negative health impacts of pregnancy-induced metabolic imbalances, their molecular causes remain unclear. Therefore, the present study investigated the molecular mechanisms responsible for orchestrating the metabolic changes observed during pregnancy. Methods Initially, we investigated the hypothalamic expression of key genes that could influence the energy balance and glucose homeostasis during pregnancy. Based on these results, we generated a conditional knockout mouse that lacks the suppressor of cytokine signaling-3 (SOCS3) only in leptin receptor-expressing cells and studied these animals during pregnancy. Results Among several genes involved in leptin resistance, only SOCS3 was increased in the hypothalamus of pregnant mice. Remarkably, SOCS3 deletion from leptin receptor-expressing cells prevented pregnancy-induced hyperphagia, body fat accumulation as well as leptin and insulin resistance without affecting the ability of the females to carry their gestation to term. Additionally, we found that SOCS3 conditional deletion protected females against long-term postpartum fat retention and streptozotocin-induced gestational diabetes. Conclusions Our study identified the increased hypothalamic expression of SOCS3 as a key mechanism responsible for triggering pregnancy-induced leptin resistance and metabolic adaptations. These findings not only help to explain a common phenomenon of the mammalian physiology, but it may also aid in the development of approaches to prevent and treat gestational metabolic imbalances.
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Key Words
- ARH, arcuate nucleus of the hypothalamus
- DIO, diet-induced obesity
- DMH, dorsomedial nucleus of the hypothalamus
- EGWG, excessive gestational weight gain
- GDM, gestational diabetes mellitus
- GH-V, placental growth hormone
- GTT, glucose tolerance test
- Gestational diabetes
- Hypothalamus
- IR, insulin receptor
- ITT, insulin tolerance test
- LepR, leptin receptor
- Leptin
- Leptin resistance
- Obesity
- PKC, protein kinase C
- RP, retroperitoneal
- SOCS3, suppressor of cytokine signaling-3
- STZ, streptozotocin
- Suppressor of cytokine signaling
- VMH, ventromedial nucleus of the hypothalamus
- pSTAT3, phosphorylation of the signal transducer and activator of transcription 3
- pSTAT3-ir, pSTAT3-immunoreactive
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Affiliation(s)
- Thais T Zampieri
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
| | - Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
| | - Isadora C Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
| | - João A B Pedroso
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
| | - Daniella C Buonfiglio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, SP, 05508-000, Brazil
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Qin H, Zhang X, Ye F, Zhong L. High-fat diet-induced changes in liver thioredoxin and thioredoxin reductase as a novel feature of insulin resistance. FEBS Open Bio 2014; 4:928-35. [PMID: 25426412 PMCID: PMC4239481 DOI: 10.1016/j.fob.2014.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 10/28/2014] [Accepted: 10/28/2014] [Indexed: 12/25/2022] Open
Abstract
High-fat diet (HFD) can induce oxidative stress. Thioredoxin (Trx) and thioredoxin reductase (TrxR) are critical antioxidant proteins but how they are affected by HFD remains unclear. Using HFD-induced insulin-resistant mouse model, we show here that liver Trx and TrxR are significantly decreased, but, remarkably, the degree of their S-acylation is increased after consuming HFD. These HFD-induced changes in Trx/TrxR may reflect abnormalities of lipid metabolism and insulin signaling transduction. HFD-driven accumulation of 4-hydroxynonenal is another potential mechanism behind inactivation and decreased expression of Trx/TrxR. Thus, we propose HFD-induced impairment of liver Trx/TrxR as major contributor to oxidative stress and as a novel feature of insulin resistance.
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Key Words
- 4-HNE, 4-hydroxynonenal
- ASK-1, apoptosis signal-regulating kinase-1
- Gpx, glutathione peroxidase
- HFD, high-fat diet
- High-fat diet
- IRS-1, insulin receptor substrate-1
- ITT, insulin tolerance test
- Insulin resistance
- OGTT, oral glucose tolerance test
- PTP-1B, protein-tyrosine phophatase-1B
- S-acylation
- Thioredoxin
- Thioredoxin reductase
- Trx, thioredoxin
- TrxR, thioredoxin reductase
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Affiliation(s)
- Huijun Qin
- College of Life Sciences, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Xiaolin Zhang
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Perking Union Medical College, 100050 Beijing, China
| | - Fei Ye
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Perking Union Medical College, 100050 Beijing, China
| | - Liangwei Zhong
- College of Life Sciences, University of Chinese Academy of Sciences, 100049 Beijing, China
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27
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Pedroso JAB, Buonfiglio DC, Cardinali LI, Furigo IC, Ramos-Lobo AM, Tirapegui J, Elias CF, Donato J. Inactivation of SOCS3 in leptin receptor-expressing cells protects mice from diet-induced insulin resistance but does not prevent obesity. Mol Metab 2014; 3:608-18. [PMID: 25161884 PMCID: PMC4142399 DOI: 10.1016/j.molmet.2014.06.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 05/29/2014] [Accepted: 06/03/2014] [Indexed: 02/05/2023] Open
Abstract
Therapies that improve leptin sensitivity have potential as an alternative treatment approach against obesity and related comorbidities. We investigated the effects of Socs3 gene ablation in different mouse models to understand the role of SOCS3 in the regulation of leptin sensitivity, diet-induced obesity (DIO) and glucose homeostasis. Neuronal deletion of SOCS3 partially prevented DIO and improved glucose homeostasis. Inactivation of SOCS3 only in LepR-expressing cells protected against leptin resistance induced by HFD, but did not prevent DIO. However, inactivation of SOCS3 in LepR-expressing cells protected mice from diet-induced insulin resistance by increasing hypothalamic expression of Katp channel subunits and c-Fos expression in POMC neurons. In summary, the regulation of leptin signaling by SOCS3 orchestrates diet-induced changes on glycemic control. These findings help to understand the molecular mechanisms linking obesity and type 2 diabetes, and highlight the potential of SOCS3 inhibitors as a promising therapeutic approach for the treatment of diabetes.
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Key Words
- AP, area postrema
- ARH, arcuate nucleus of the hypothalamus
- DIO, diet-induced obesity
- DMV, dorsal motor nucleus of the vagus
- GTT, glucose tolerance test
- HFD, high-fat diet
- High-fat diet
- Hypothalamus
- ITT, insulin tolerance test
- KO, knockout
- LepR, leptin receptor
- Leptin resistance
- NTS, nucleus of the solitary tract
- PI3K, phosphatidylinositol 3-kinase
- PKC, protein kinase C
- POMC
- POMC, proopiomelanocortin
- PTPs, protein-tyrosine phosphatases
- SOCS3, suppressor of cytokine signaling-3
- Suppressor of cytokine signaling-3
- T2DM, type 2 diabetes mellitus
- Type 2 diabetes mellitus
- VMH, ventromedial nucleus of the hypothalamus
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Affiliation(s)
- João A B Pedroso
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Daniella C Buonfiglio
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Lais I Cardinali
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Isadora C Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Angela M Ramos-Lobo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Julio Tirapegui
- Department of Food Science and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Carol F Elias
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA ; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA ; Department of Internal Medicine, Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
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28
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Kim JH, Meyers MS, Khuder SS, Abdallah SL, Muturi HT, Russo L, Tate CR, Hevener AL, Najjar SM, Leloup C, Mauvais-Jarvis F. Tissue-selective estrogen complexes with bazedoxifene prevent metabolic dysfunction in female mice. Mol Metab 2014; 3:177-90. [PMID: 24634829 DOI: 10.1016/j.molmet.2013.12.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 12/20/2013] [Accepted: 12/21/2013] [Indexed: 12/11/2022] Open
Abstract
Pairing the selective estrogen receptor modulator bazedoxifene (BZA) with estrogen as a tissue-selective estrogen complex (TSEC) is a novel menopausal therapy. We investigated estrogen, BZA and TSEC effects in preventing diabetisity in ovariectomized mice during high-fat feeding. Estrogen, BZA or TSEC prevented fat accumulation in adipose tissue, liver and skeletal muscle, and improved insulin resistance and glucose intolerance without stimulating uterine growth. Estrogen, BZA and TSEC improved energy homeostasis by increasing lipid oxidation and energy expenditure, and promoted insulin action by enhancing insulin-stimulated glucose disposal and suppressing hepatic glucose production. While estrogen improved metabolic homeostasis, at least partially, by increasing hepatic production of FGF21, BZA increased hepatic expression of Sirtuin1, PPARα and AMPK activity. The metabolic benefits of BZA were lost in estrogen receptor-α deficient mice. Thus, BZA alone or in TSEC produces metabolic signals of fasting and caloric restriction and improves energy and glucose homeostasis in female mice.
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Key Words
- AMPKα, AMP-activated protein kinase α
- AUC, area-under the curve
- Akt, protein kinase B
- BAT, brown adipose tissue
- BZA, bazedoxifene
- Bazedoxifene
- CE, conjugated equine estrogens
- E2, 17β-estradiol
- ER, estrogen receptor
- FAS, fatty acid synthase
- FGF21, fibroblast growth factor 21
- GIR, glucose infusion rate
- H&E, hematoxylin and eosin
- HFD, high-fat diet
- HGP, hepatic glucose production
- ITT, insulin tolerance test
- Insulin resistance
- LPL, lipoprotein lipase
- Lcn2, lipocalin 2
- Menopause
- Metabolic syndrome
- NAFLD, non-alcoholic fatty liver disease
- OGTT, oral glucose tolerance test
- OVX, ovariectomy
- PTT, pyruvate tolerance test
- RBP4, retinol binding protein 4
- RER, respiratory exchange ratio
- Rd, rate of whole-body glucose disappearance
- SERM, selective estrogen receptor modulator
- TBARS, thiobarbituric acid reactive substances
- TG, triacylglycerol
- TSEC, tissue-selective estrogen complex
- Tissue-selective estrogen complexes
- Type 2 diabetes
- UCPs, uncoupling proteins
- VO2, oxygen consumption
- WAT, white adipose tissue.
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Affiliation(s)
- Jun Ho Kim
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Matthew S Meyers
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Saja S Khuder
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Simon L Abdallah
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Harrison T Muturi
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Lucia Russo
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Chandra R Tate
- Department of Medicine, Division of Endocrinology and Metabolism, Tulane University Health Sciences Center, School of Medicine, New Orleans, LA 70112, USA
| | - Andrea L Hevener
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Sonia M Najjar
- Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Corinne Leloup
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Franck Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA ; Department of Medicine, Division of Endocrinology and Metabolism, Tulane University Health Sciences Center, School of Medicine, New Orleans, LA 70112, USA
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29
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Abstract
Both type 1 and type 2 diabetes are associated with insufficient functional β-cell mass. Understanding intracellular signaling pathways associated with this decline is important in broadening our understanding of the disease and potential therapeutic strategies. The hypoxia inducible factor pathway (HIF) plays a critical role in cellular adaptation to hypoxic conditions. Activation of this pathway increases expression of numerous genes involved in multiple cellular processes and has been shown to impact the regulation of β-cell function. Previously, deletion of HIF-1α or HIF-1β in pancreatic β-cells, as well as constitutive activation of the HIF pathway in β-cells, was shown to result in glucose intolerance and impaired insulin secretion. The objective of this study was to delineate roles of HIF-2α overexpression in pancreatic β-cells in vivo. We overexpressed HIF-2α in pancreatic β-cells by employing the Cre-loxP system driven by the Pdx1 promoter to delete a stop codon. Our study revealed that pancreatic HIF-2α overexpression does not result in significant differences in glucose tolerance, insulin sensitivity or β-cell area compared to wild-type littermates under basal conditions or after high fat diet. Together, our study shows excess HIF-2α in the pancreatic β-cells does not play a significant role in β-cell function and glucose homeostasis.
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Key Words
- ARNT, aryl hydrocarbon receptor nuclear translocator
- EPAS1, endothelial PAS domain protein 1
- GLUT1 glucose transporter 1
- GTT, glucose tolerance test
- HFD, high fat diet
- HIF, hypoxia inducible factor
- HIF-1α, hypoxia inducible factor-1 α
- HIF-1β, hypoxia inducible factor-1 β
- HIF-2α, hypoxia inducible factor-2 α
- Hypoxia inducible factor β cell glucose homeostasis diabetes mellitus pancreas
- ITT, insulin tolerance test
- OE, overexpression
- VEGF, vascular endothelial growth factor
- VHL, von Hippel-Lindau
- WT, wild-type
- i.p., intraperitoneal
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Affiliation(s)
- Jara J Brunt
- Toronto General Research
Institute; Toronto, Canada
- Institute of Medical Science; University of
Toronto; Toronto, Canada
| | - Sally Yu Shi
- Toronto General Research
Institute; Toronto, Canada
- Institute of Medical Science; University of
Toronto; Toronto, Canada
| | | | - Tharini Sivasubramaniyam
- Toronto General Research
Institute; Toronto, Canada
- Institute of Medical Science; University of
Toronto; Toronto, Canada
| | - Erica P Cai
- Toronto General Research
Institute; Toronto, Canada
- Institute of Medical Science; University of
Toronto; Toronto, Canada
| | - Minna Woo
- Toronto General Research
Institute; Toronto, Canada
- Institute of Medical Science; University of
Toronto; Toronto, Canada
- Division of Endocrinology; Department of
Medicine; Toronto General Hospital; University Health Network; University of
Toronto; Toronto, Canada
- Correspondence to: Minna Woo;
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30
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Abstract
Non-alcoholic fatty liver disease (NAFLD) is an important cause of liver disease worldwide with prevalence ranging from 10% to 30% in various countries. It has become an important cause of unexplained rise in transaminases, cryptogenic cirrhosis, and cryptogenic hepatocellular carcinoma. Pathogenesis is related to obesity, insulin resistance, oxidative stress, lipotoxicity, and resultant inflammation in the liver progressing to fibrosis. Pharmacological treatment in patients with NAFLD is still evolving and the treatment of these patients rests upon lifestyle modification with diet and exercise being the cornerstones of therapy. While there are many similarities between patients with NAFLD from Asia and the West, there are certain features which make the patients with NAFLD from Asia stand apart. This review highlights the data on NAFLD from Asia comparing it with the data from the West.
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Key Words
- ALT, alanine aminotransferases
- APO C3, apolipoprotein C3
- CC, cryptogenic cirrhosis
- CLD, chronic liver disease
- Cirrhosis
- DM, diabetes mellitus
- FRAP, ferric-reducing ability of plasma
- GSH, glutathione
- HCC, hepatocellular carcinoma
- HCV, hepatitis C virus
- HDL, high-density lipoprotein
- HTN, hypertension
- IR, insulin resistance
- ITT, insulin tolerance test
- MS, metabolic syndrome
- NAFLD, non-alcoholic fatty liver disease
- NASH, non-alcoholic steatohepatitis
- PCC, protein carbonyl
- PNPLA3, patatin-like phospholipase domain-containing protein 3
- SOD, superoxide dismutase
- TBARS, thiobarbituric acid reactive substances
- TG, triglyceride
- TGF-β, transforming growth factor-beta
- TNF-α, tumor necrosis factor-alfa
- VLDL, very low density lipoproteins
- diabetes mellitus
- gene mutations
- insulin resistance
- metabolic syndrome
- non-alcoholic steatohepatitis
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