1
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Siewe N, Friedman A. A mathematical model of obesity-induced type 2 diabetes and efficacy of anti-diabetic weight reducing drug. J Theor Biol 2024; 581:111756. [PMID: 38307451 DOI: 10.1016/j.jtbi.2024.111756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/04/2023] [Accepted: 01/26/2024] [Indexed: 02/04/2024]
Abstract
The dominant paradigm for modeling the obesity-induced T2DM (type 2 diabetes mellitus) today focuses on glucose and insulin regulatory systems, diabetes pathways, and diagnostic test evaluations. The problem with this approach is that it is not possible to explicitly account for the glucose transport mechanism from the blood to the liver, where the glucose is stored, and from the liver to the blood. This makes it inaccurate, if not incorrect, to properly model the concentration of glucose in the blood in comparison to actual glycated hemoglobin (A1C) test results. In this paper, we develop a mathematical model of glucose dynamics by a system of ODEs. The model includes the mechanism of glucose transport from the blood to the liver, and from the liver to the blood, and explains how obesity is likely to lead to T2DM. We use the model to evaluate the efficacy of an anti-T2DM drug that also reduces weight.
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Affiliation(s)
- Nourridine Siewe
- School of Mathematics and Statistics, College of Science, Rochester Institute of Technology, Rochester, NY, USA.
| | - Avner Friedman
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
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2
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Williams EJ, Guilleminault L, Berthon BS, Eslick S, Wright T, Karihaloo C, Gately M, Baines KJ, Wood LG. Sulforaphane Reduces Pro-Inflammatory Response To Palmitic Acid In Monocytes And Adipose Tissue Macrophages. J Nutr Biochem 2022; 104:108978. [DOI: 10.1016/j.jnutbio.2022.108978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/03/2021] [Accepted: 02/09/2022] [Indexed: 10/18/2022]
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3
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Tański W, Świątoniowska-Lonc N, Tabin M, Jankowska-Polańska B. The Relationship between Fatty Acids and the Development, Course and Treatment of Rheumatoid Arthritis. Nutrients 2022; 14:nu14051030. [PMID: 35268002 PMCID: PMC8912339 DOI: 10.3390/nu14051030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023] Open
Abstract
For this systematic review, a search of the relevant literature was conducted in the EMBASE and PubMed databases. We used the following terms: ‘rheumatoid arthritis’ in conjunction with ‘fatty acid’. The following inclusion criteria had to be satisfied for the studies to be included in the analysis: an RCT/observational/cohort study published in English. A total of seventy-one studies were analysed. The presented systematic review of the available data indicates that increased consumption of omega-3 fatty acids (FAs) may have a beneficial effect on human health by decreasing pain and disease activity in patients with RA. The beneficial effect of unsaturated FA on the clinical parameters of RA was demonstrated in all 71 studies analysed. The content of omega-3 FAs in the diet and the consumption of fish, which are their main source, may contribute to a reduced incidence of RA. FAs are an essential component in the synthesis of eicosanoids that exhibit anti-inflammatory properties. Due to the documented positive influence of unsaturated FAs on treatment outcomes, the use of a diet rich in long-chain unsaturated FAs should be the standard of care, along with pharmacotherapy, in the treatment of RA patients. An important element in the control of the treatment process should be the routine assessment of the quality of life of RA patients.
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Affiliation(s)
- Wojciech Tański
- Department of Internal Medicine, 4th Military Teaching Hospital, 50-981 Wroclaw, Poland;
| | - Natalia Świątoniowska-Lonc
- Center for Research and Innovation, 4th Military Teaching Hospital, 50-981 Wroclaw, Poland;
- Correspondence:
| | - Mateusz Tabin
- Clinical Endocrinology Department, 4th Military Teaching Hospital, 50-981 Wroclaw, Poland;
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4
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Wu Q, Zhao M, He X, Xue R, Li D, Yu X, Wang S, Zang W. Acetylcholine reduces palmitate-induced cardiomyocyte apoptosis by promoting lipid droplet lipolysis and perilipin 5-mediated lipid droplet-mitochondria interaction. Cell Cycle 2021; 20:1890-1906. [PMID: 34424820 DOI: 10.1080/15384101.2021.1965734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Lipid droplets (LDs), which are neutral lipid storage organelles, are important for lipid metabolism and energy homeostasis. LD lipolysis and interactions with mitochondria are tightly coupled to cellular metabolism and may be potential targets to buffer the effects of excessive toxic lipid species levels. Acetylcholine (ACh), the major neurotransmitter of the vagus nerve, exhibits cardioprotective effects. However, limited research has focused on its effects on LD lipolysis and the LD-mitochondria association in fatty acid (FA) overload models. Here, we reveal that palmitate (PA) induces an increase in expression of the FA transport protein cluster of differentiation 36 (CD36) and LD formation; remarkably reduces the expression of lipases involved in triacylglycerol (TAG) lipolysis, such as adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and monoacylglycerol lipase (MGL); impairs LD-mitochondria interaction; and decreases perilipin 5 (PLIN5) expression, resulting in LD accumulation and mitochondrial dysfunction, which ultimately lead to cardiomyocyte apoptosis. ACh significantly upregulates PLIN5 expression and improved LD lipolysis and the LD-mitochondria association. Moreover, ACh reduces CD36 expression, LD deposition and mitochondrial dysfunction, ultimately suppressing apoptosis in PA-treated neonatal rat ventricular cardiomyocytes (NRVCs). Knockdown of PLIN5, which plays a role in LD-mitochondria contact site formation, abolishes the protective effects of ACh in PA-treated NRVCs. Thus, ACh protects cardiomyocytes from PA-induced apoptosis, at least partly, by promoting LD lipolysis and activating LD-mitochondria interactions via PLIN5. These findings may aid in developing novel therapeutic approaches that target LD lipolysis and PLIN5-mediated LD-mitochondria interactions to prevent or alleviate lipotoxic cardiomyopathy.
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Affiliation(s)
- Qing Wu
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Ming Zhao
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Xi He
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Runqing Xue
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Dongling Li
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Xiaojiang Yu
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
| | - Shengpeng Wang
- Cardiovascular Research Center, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, P.R. China
| | - Weijin Zang
- Department of Pharmacology,School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, P.R. China
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5
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Ferreira HB, Melo T, Paiva A, Domingues MDR. Insights in the Role of Lipids, Oxidative Stress and Inflammation in Rheumatoid Arthritis Unveiled by New Trends in Lipidomic Investigations. Antioxidants (Basel) 2021; 10:antiox10010045. [PMID: 33401700 PMCID: PMC7824304 DOI: 10.3390/antiox10010045] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 02/07/2023] Open
Abstract
Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.
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Affiliation(s)
- Helena Beatriz Ferreira
- Mass Spectrometry Center & QOPNA/LAQV-REQUIMTE, Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal;
| | - Tânia Melo
- Mass Spectrometry Center & QOPNA/LAQV-REQUIMTE, Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal;
- CESAM, Centre for Environmental and Marine Studies, Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
- Correspondence: (T.M.); (M.d.R.D.); Tel.: +351-234-370-698 (M.d.R.D.)
| | - Artur Paiva
- Unidade de Gestão Operacional em Citometria, Centro Hospitalar e Universitário de Coimbra (CHUC), 3004-561 Coimbra, Portugal;
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
- Instituto Politécnico de Coimbra, ESTESC-Coimbra Health School, Ciências Biomédicas Laboratoriais, 3046-854 Coimbra, Portugal
| | - Maria do Rosário Domingues
- Mass Spectrometry Center & QOPNA/LAQV-REQUIMTE, Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal;
- CESAM, Centre for Environmental and Marine Studies, Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
- Correspondence: (T.M.); (M.d.R.D.); Tel.: +351-234-370-698 (M.d.R.D.)
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Wilhelmi de Toledo F, Grundler F, Sirtori CR, Ruscica M. Unravelling the health effects of fasting: a long road from obesity treatment to healthy life span increase and improved cognition. Ann Med 2020; 52:147-161. [PMID: 32519900 PMCID: PMC7877980 DOI: 10.1080/07853890.2020.1770849] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In recent years a revival of interest has emerged in the health benefits of intermittent fasting and long-term fasting, as well as of other related nutritional strategies. In addition to meal size and composition a new focus on time and frequency of meals has gained attention. The present review will investigate the effects of the main forms of fasting, activating the metabolic switch from glucose to fat and ketones (G-to-K), starting 12-16 h after cessation or strong reduction of food intake. During fasting the deactivation of mTOR regulated nutrient signalling pathways and activation of the AMP protein kinase trigger cell repair and inhibit anabolic processes. Clinical and animal studies have clearly indicated that modulating diet and meal frequency, as well as application of fasting patterns, e.g. intermittent fasting, periodic fasting, or long-term fasting are part of a new lifestyle approach leading to increased life and health span, enhanced intrinsic defences against oxidative and metabolic stresses, improved cognition, as well as a decrease in cardiovascular risk in both obese and non-obese subjects. Finally, in order to better understand the mechanisms beyond fasting-related changes, human studies as well as non-human models closer to human physiology may offer useful clues.KEY-MESSAGESBiochemical changes during fasting are characterised by a glucose to ketone switch, leading to a rise of ketones, advantageously used for brain energy, with consequent improved cognition.Ketones reduce appetite and help maintain effective fasting.Application of fasting patterns increases healthy life span and defences against oxidative and metabolic stresses.Today's strategies for the use of therapeutic fasting are based on different protocols, generally relying on intermittent fasting, of different duration and calorie intake.Long-term fasting, with durations between 5 and 21 days can be successfully repeated in the course of a year.
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Affiliation(s)
| | - Franziska Grundler
- Buchinger Wilhelmi Clinic, Wilhelm-Beck-Straße 27, Überlingen, Germany.,Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Cesare R Sirtori
- Dyslipidemia Center, A.S.S.T. Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Massimiliano Ruscica
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
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7
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Hosseini M, Poljak A, Braidy N, Crawford J, Sachdev P. Blood fatty acids in Alzheimer's disease and mild cognitive impairment: A meta-analysis and systematic review. Ageing Res Rev 2020; 60:101043. [PMID: 32194194 DOI: 10.1016/j.arr.2020.101043] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/23/2019] [Accepted: 03/05/2020] [Indexed: 12/31/2022]
Abstract
Plasma fatty acids have been reported to be dysregulated in mild cognitive impairment (MCI) and Alzheimer's disease (AD), though outcomes are not always consistent, and subject numbers often small. Our aim was to use a meta-analysis and systematic review approach to identify if plasma fatty acid dysregulation would be observed in case control studies of AD and MCI. Six databases were searched for studies reporting quantified levels of fatty acids in MCI and/or AD individuals, relative to cognitively normal controls. Docosahexaenoic (DHA) and vaccenic acids were significantly lower and higher respectively in MCI relative to controls. Total fatty acids were 27.2% lower in AD relative to controls, and this was reflected almost uniformly in all specific fatty acids in AD. Changes to plasma/serum fatty acids were identified in both MCI and AD relative to age and gender matched controls. Differences were greatest in AD, in both total number of fatty acids significantly altered, and the degree of change. Docosahexaenoic acid was lower in both MCI and AD, suggesting that it may be a driver of pathology.
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Affiliation(s)
- Mahboobeh Hosseini
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
| | - Anne Poljak
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Mark Wainwright Analytical Centre, Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, Australia; School of Medical Sciences, University of New South Wales, Sydney, Australia.
| | - Nady Braidy
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
| | - John Crawford
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia.
| | - Perminder Sachdev
- Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Euroa Centre, Prince of Wales Hospital, Sydney, Australia.
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8
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Ha SY, Qiu XM, Lai ZZ, Yang HL, Wang Y, Ruan LY, Shi JW, Zhu XY, Li DJ, Li MQ. Excess palmitate induces decidual stromal cell apoptosis via the TLR4/JNK/NF-kB pathways and possibly through glutamine oxidation. Mol Hum Reprod 2020; 26:88-100. [PMID: 31977025 DOI: 10.1093/molehr/gaaa004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/23/2019] [Accepted: 01/08/2020] [Indexed: 12/30/2022] Open
Abstract
During gestation, excess palmitate (PA) is enriched in decidua. Both excess PA and decidual dysfunctions are associated with numerous adverse pregnancy outcomes such as gestational diabetes, preeclampsia and preterm birth and intrauterine growth restriction. Here, mRNA data about the effects of PA were collected from multiple databases and analyzed. Human decidual tissues were obtained from clinically normal pregnancies, terminated for non-medical reasons, during the first trimester, and decidual stromal cells (DSCs) were isolated and exposed to PA, alone or together with the inhibitors of Toll-like receptor 4 (TLR4), Jun N-terminal kinase (JNK), nuclear factor-kappa-gene binding (NF-kB) or glutamine (GLN) oxidation. Furthermore, DSCs were transfected with lentiviral particles overexpressing human TLR4. We demonstrate that excess PA interacting with its receptor TLR4 disturbs DSC hemostasis during the first trimester. Specifically, high PA signal induced DSC apoptosis and formed an inflammatory program (elevated interleukin-1 beta and decreased interleukin-10) via the activation of TLR4/JNK/NF-kB pathways. A complexed cross-talk was found between TLR4/JNK/NF-kB signals and PA deposition in DSCs. Besides, under an excess PA environment, GLN oxidation was significantly enhanced in DSCs and the suppression of GLN oxidation further augmented PA-mediated DSC apoptosis and inflammatory responses. In conclusion, excess PA induces apoptosis and inflammation in DSCs via the TLR4/JNK/NF-kB pathways, which can be augmented by the suppression of GLN oxidation.
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Affiliation(s)
- Si-Yao Ha
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Xue-Min Qiu
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Zhen-Zhen Lai
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Hui-Li Yang
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Yan Wang
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Lu-Yu Ruan
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Jia-Wei Shi
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Xiao-Yong Zhu
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China.,Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200011, People's Republic of China
| | - Da-Jin Li
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China
| | - Ming-Qing Li
- Laboratory for Reproductive Immunology, National Health Commission (NHC) Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200082, People's Republic of China.,Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Hospital of Obstetrics and Gynecology, Shanghai Medical School, Fudan University, Shanghai 200011, People's Republic of China
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9
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Fatima S, Hu X, Gong RH, Huang C, Chen M, Wong HLX, Bian Z, Kwan HY. Palmitic acid is an intracellular signaling molecule involved in disease development. Cell Mol Life Sci 2019; 76:2547-2557. [PMID: 30968170 PMCID: PMC11105207 DOI: 10.1007/s00018-019-03092-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/31/2019] [Accepted: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Emerging evidence shows that palmitic acid (PA), a common fatty acid in the human diet, serves as a signaling molecule regulating the progression and development of many diseases at the molecular level. In this review, we focus on its regulatory roles in the development of five pathological conditions, namely, metabolic syndrome, cardiovascular diseases, cancer, neurodegenerative diseases, and inflammation. We summarize the clinical and epidemiological studies; and also the mechanistic studies which have identified the molecular targets for PA in these pathological conditions. Activation or inactivation of these molecular targets by PA controls disease development. Therefore, identifying the specific targets and signaling pathways that are regulated by PA can give us a better understanding of how these diseases develop for the design of effective targeted therapeutics.
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Affiliation(s)
- Sarwat Fatima
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Xianjing Hu
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Rui-Hong Gong
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Chunhua Huang
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Minting Chen
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Hoi Leong Xavier Wong
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China
| | - Zhaoxiang Bian
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China.
| | - Hiu Yee Kwan
- School of Chinese Medicine, Centre of Clinical Research for Chinese Medicine, and Centre for Cancer and Inflammation Research, Hong Kong Baptist University, Hong Kong, China.
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10
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Walker AE, Breevoort SR, Durrant JR, Liu Y, Machin DR, Dobson PS, Nielson EI, Meza AJ, Islam MT, Donato AJ, Lesniewski LA. The pro-atherogenic response to disturbed blood flow is increased by a western diet, but not by old age. Sci Rep 2019; 9:2925. [PMID: 30814657 PMCID: PMC6393500 DOI: 10.1038/s41598-019-39466-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 01/24/2019] [Indexed: 12/12/2022] Open
Abstract
Atherogenic remodeling often occurs at arterial locations with disturbed blood flow (i.e., low or oscillatory) and both aging and western diet (WD) increase the likelihood for pro-atherogenic remodeling. However, it is unknown if old age and/or a WD modify the pro-atherogenic response to disturbed blood flow. We induced disturbed blood flow by partial carotid ligation (PCL) of the left carotid artery in young and old, normal chow (NC) or WD fed male B6D2F1 mice. Three weeks post-PCL, ligated carotid arteries had greater intima media thickness, neointima formation, and macrophage content compared with un-ligated arteries. WD led to greater remodeling and macrophage content in the ligated artery compared with NC mice, but these outcomes were similar between young and old mice. In contrast, nitrotyrosine content, a marker of oxidative stress, did not differ between WD and NC fed mice, but was greater in old compared with young mice in both ligated and un-ligated carotid arteries. In primary vascular smooth muscle cells, aging reduced proliferation, whereas conditioned media from fatty acid treated endothelial cells increased proliferation. Taken together, these findings suggest that the remodeling and pro-inflammatory response to disturbed blood flow is increased by WD, but is not increased by aging.
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Affiliation(s)
- Ashley E Walker
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA. .,Department of Human Physiology, University of Oregon, Eugene, Oregon, USA.
| | - Sarah R Breevoort
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | | | - Yu Liu
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Daniel R Machin
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.,Geriatrics Research Education and Clinical Center, Veteran's Affairs Medical Center, Salt Lake City, Utah, USA
| | - Parker S Dobson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Elizabeth I Nielson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Antonio J Meza
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Md Torikul Islam
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA
| | - Anthony J Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.,Geriatrics Research Education and Clinical Center, Veteran's Affairs Medical Center, Salt Lake City, Utah, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA
| | - Lisa A Lesniewski
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.,Geriatrics Research Education and Clinical Center, Veteran's Affairs Medical Center, Salt Lake City, Utah, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah, USA
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11
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Sid V, Siow YL, Shang Y, Woo CW, O K. High-fat diet consumption reduces hepatic folate transporter expression via nuclear respiratory factor-1. J Mol Med (Berl) 2018; 96:1203-1213. [PMID: 30178194 DOI: 10.1007/s00109-018-1688-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 08/03/2018] [Accepted: 08/17/2018] [Indexed: 12/13/2022]
Abstract
Folate is an essential micronutrient for biological function. The liver, a primary organ for folate metabolism and storage, plays an important role in folate homeostasis. Proton-coupled folate transporter (PCFT) and reduced folate carrier (RFC) are the major folate transporters responsible for folate uptake at basolateral membrane of hepatocytes. Low serum folate levels are frequently associated with obesity. We investigated the mechanism that regulated folate status in a mouse model with diet-induced obesity. Mice (C57BL/6J) were fed a high-fat diet (60% kcal fat) for 8 weeks. Mice displayed increased hepatic lipid accumulation and decreased folate levels in the liver and serum compared to mice fed a normal chow diet (10% kcal fat). High-fat diet-fed mice had low expression of PCFT and RFC and decreased nuclear respiratory factor-1 (NRF-1)/DNA-binding activity. Treatment with NRF-1 siRNA or palmitic acid reduced folate transporter expression in hepatocytes. Inhibition of NRF-1 mediated folate transporter expression significantly reduced intracellular folate levels. These results suggest that chronic consumption of high-fat diets impairs folate transporter expression via NRF-1-dependent mechanism, leading to reduced hepatic folate storage. Understanding the regulation of folate homeostasis in obesity may have an important implication in current guideline of folate intake. KEY MESSAGES: Serum and liver folate levels are decreased in diet-induced obese mice. Chronic high-fat diet consumption impairs expression of hepatic PCFT and RFC. NRF-1 regulates hepatic folate transporters expression and folate levels.
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Affiliation(s)
- Victoria Sid
- St. Boniface Hospital Research Centre, Winnipeg, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
| | - Yaw L Siow
- St. Boniface Hospital Research Centre, Winnipeg, Canada
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada
- Agriculture and Agri-Food Canada, Winnipeg, Canada
| | - Yue Shang
- St. Boniface Hospital Research Centre, Winnipeg, Canada
- Department of Animal Science, University of Manitoba, Winnipeg, Canada
| | - Connie W Woo
- Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong, SAR, China.
| | - Karmin O
- St. Boniface Hospital Research Centre, Winnipeg, Canada.
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.
- Department of Animal Science, University of Manitoba, Winnipeg, Canada.
- Laboratory of Integrative Biology, CCARM, St. Boniface Hospital Research Centre, 351 Tache Avenue, Winnipeg, Manitoba, R2H 2A6, Canada.
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12
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Natarajan SK, Stringham BA, Mohr AM, Wehrkamp CJ, Lu S, Phillippi MA, Harrison-Findik D, Mott JL. FoxO3 increases miR-34a to cause palmitate-induced cholangiocyte lipoapoptosis. J Lipid Res 2017; 58:866-875. [PMID: 28250026 PMCID: PMC5408604 DOI: 10.1194/jlr.m071357] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 02/27/2017] [Indexed: 01/07/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) patients have elevated plasma saturated free fatty acid levels. These toxic fatty acids can induce liver cell death and our recent results demonstrated that the biliary epithelium may be susceptible to lipotoxicity. Here, we explored the molecular mechanisms of cholangiocyte lipoapoptosis in cell culture and in an animal model of NASH. Treatment of cholangiocytes with palmitate (PA) showed increased caspase 3/7 activity and increased levels of cleaved poly (ADP-ribose) polymerase and cleaved caspase 3, demonstrating cholangiocyte lipoapoptosis. Interestingly, treatment with PA significantly increased the levels of microRNA miR-34a, a pro-apoptotic microRNA known to be elevated in NASH. PA induction of miR-34a was abolished in cholangiocytes transduced with forkhead family of transcription factor class O (FoxO)3 shRNA, demonstrating that FoxO3 activation is upstream of miR-34a and suggesting that FoxO3 is a novel transcriptional regulator of miR-34a. Further, anti-miR-34a protected cholangiocytes from PA-induced lipoapoptosis. Direct and indirect targets of miR-34a, such as SIRT1, receptor tyrosine kinase (MET), Kruppel-like factor 4, fibroblast growth factor receptor (FGFR)1, and FGFR4, were all decreased in PA-treated cholangiocytes. SIRT1 and MET were partially rescued by a miR-34a antagonist. Cholangiocyte apoptosis and miR-34a were dramatically increased in the liver of mice with early histologic features of NASH. Our study provides evidence for the pro-apoptotic role of miR-34a in PA-induced cholangiocyte lipoapoptosis in culture and in the liver.
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Affiliation(s)
- Sathish Kumar Natarajan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Bailey A Stringham
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Ashley M Mohr
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Cody J Wehrkamp
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Sizhao Lu
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Mary Anne Phillippi
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Dee Harrison-Findik
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
| | - Justin L Mott
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha NE
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13
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Tanka-Salamon A, Komorowicz E, Szabó L, Tenekedjiev K, Kolev K. Free Fatty Acids Modulate Thrombin Mediated Fibrin Generation Resulting in Less Stable Clots. PLoS One 2016; 11:e0167806. [PMID: 27942000 PMCID: PMC5152833 DOI: 10.1371/journal.pone.0167806] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/21/2016] [Indexed: 12/19/2022] Open
Abstract
Upon platelet activation, free fatty acids are released at the stage of thrombus formation, but their effects on fibrin formation are largely unexplored. Our objective was to characterize the kinetic effects of fatty acids on thrombin activity, as well as the structural and mechanical properties of the resultant fibrin clots. Thrombin activity on fibrinogen was followed by turbidimetry and detailed kinetic characterization was performed using a fluorogenic short peptide substrate. The viscoelastic properties of fibrin were measured with rotatory oscillation rheometer, whereas its structure was analyzed with scanning electron microscopy (SEM). In turbidimetric assays of fibrin generation, oleate and stearate at physiologically relevant concentrations (60–600 μM) produced a bell-shaped inhibitory dose response, increasing 10- to 30-fold the time to half-maximal clotting. Oleate inhibited thrombin activity on a short peptide substrate according to a mixed-type inhibitor pattern (a 9-fold increase of the Michaelis constant, Km and a 20% decrease of the catalytic constant), whereas stearate resulted in only a minor (15%) drop in the catalytic constant without any change in the Km. Morphometric analysis of SEM images showed a 73% increase in the median fiber diameter in the presence of stearate and a 20% decrease in the presence of oleate. Concerning the viscoelastic parameters of the clots, storage and loss moduli, maximal viscosity and critical shear stress decreased by 32–65% in the presence of oleate or stearate, but loss tangent did not change indicating decreased rigidity, higher deformability and decreased internal resistance to shear stress. Our study provides evidence that free fatty acids (at concentrations comparable to those reported in thrombi) reduce the mechanical stability of fibrin through modulation of thrombin activity and the pattern of fibrin assembly.
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Affiliation(s)
- Anna Tanka-Salamon
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Erzsébet Komorowicz
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - László Szabó
- IMEC, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Kiril Tenekedjiev
- Nikola Vaptsarov Naval Academy, Varna, Bulgaria
- Australian Maritime College, University of Tasmania, Newnham, Australia
| | - Krasimir Kolev
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- * E-mail:
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14
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Schumann T, Adhikary T, Wortmann A, Finkernagel F, Lieber S, Schnitzer E, Legrand N, Schober Y, Nockher WA, Toth PM, Diederich WE, Nist A, Stiewe T, Wagner U, Reinartz S, Müller-Brüsselbach S, Müller R. Deregulation of PPARβ/δ target genes in tumor-associated macrophages by fatty acid ligands in the ovarian cancer microenvironment. Oncotarget 2016; 6:13416-33. [PMID: 25968567 PMCID: PMC4537024 DOI: 10.18632/oncotarget.3826] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/29/2015] [Indexed: 01/04/2023] Open
Abstract
The nuclear receptor peroxisome proliferator-activated receptor β/δ (PPARβ/δ) is a lipid ligand-inducible transcription factor associated with macrophage polarization. However, its function in tumor-associated macrophages (TAMs) has not been investigated to date. Here, we report the PPARβ/δ-regulated transcriptome and cistrome for TAMs from ovarian carcinoma patients. Comparison with monocyte-derived macrophages shows that the vast majority of direct PPARβ/δ target genes are upregulated in TAMs and largely refractory to synthetic agonists, but repressible by inverse agonists. Besides genes with metabolic functions, these include cell type-selective genes associated with immune regulation and tumor progression, e.g., LRP5, CD300A, MAP3K8 and ANGPTL4. This deregulation is not due to increased expression of PPARβ/δ or its enhanced recruitment to target genes. Instead, lipidomic analysis of malignancy-associated ascites revealed high concentrations of polyunsaturated fatty acids, in particular linoleic acid, acting as potent PPARβ/δ agonists in macrophages. These fatty acid ligands accumulate in lipid droplets in TAMs, thereby providing a reservoir of PPARβ/δ ligands. These observations suggest that the deregulation of PPARβ/δ target genes by ligands of the tumor microenvironment contributes to the pro-tumorigenic polarization of ovarian carcinoma TAMs. This conclusion is supported by the association of high ANGPTL4 expression with a shorter relapse-free survival in serous ovarian carcinoma.
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Affiliation(s)
- Tim Schumann
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Till Adhikary
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Annika Wortmann
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Florian Finkernagel
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Sonja Lieber
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Evelyn Schnitzer
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Nathalie Legrand
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
| | - Yvonne Schober
- Metabolomics Core Facility and Institute of Laboratory Medicine and Pathobiochemistry, Philipps University, Marburg, Germany
| | - W Andreas Nockher
- Metabolomics Core Facility and Institute of Laboratory Medicine and Pathobiochemistry, Philipps University, Marburg, Germany
| | - Philipp M Toth
- Medicinal Chemistry Core Facility and Institute of Pharmaceutical Chemistry, Philipps University, Marburg, Germany
| | - Wibke E Diederich
- Medicinal Chemistry Core Facility and Institute of Pharmaceutical Chemistry, Philipps University, Marburg, Germany
| | - Andrea Nist
- Genomics Core Facility, Philipps University, Marburg, Germany
| | - Thorsten Stiewe
- Genomics Core Facility, Philipps University, Marburg, Germany
| | - Uwe Wagner
- Clinic for Gynecology, Gynecological Oncology and Gynecological Endocrinology, Center for Tumor Biology and Immunology (ZTI), Philipps University, Marburg, Germany
| | - Silke Reinartz
- Clinic for Gynecology, Gynecological Oncology and Gynecological Endocrinology, Center for Tumor Biology and Immunology (ZTI), Philipps University, Marburg, Germany
| | | | - Rolf Müller
- Institute of Molecular Biology and Tumor Research (IMT), Philipps University, Marburg, Germany
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15
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Yasa SR, Kaki SS, Rao BB, Jain N, Penumarthy V. Synthesis, characterization and evaluation of antiproliferative activity of diisopropylphenyl esters of fatty acids from selected oils. Med Chem Res 2016. [DOI: 10.1007/s00044-016-1564-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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16
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DeBosch BJ, Heitmeier MR, Mayer AL, Higgins CB, Crowley JR, Kraft TE, Chi M, Newberry EP, Chen Z, Finck BN, Davidson NO, Yarasheski KE, Hruz PW, Moley KH. Trehalose inhibits solute carrier 2A (SLC2A) proteins to induce autophagy and prevent hepatic steatosis. Sci Signal 2016; 9:ra21. [PMID: 26905426 DOI: 10.1126/scisignal.aac5472] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Trehalose is a naturally occurring disaccharide that has gained attention for its ability to induce cellular autophagy and mitigate diseases related to pathological protein aggregation. Despite decades of ubiquitous use as a nutraceutical, preservative, and humectant, its mechanism of action remains elusive. We showed that trehalose inhibited members of the SLC2A (also known as GLUT) family of glucose transporters. Trehalose-mediated inhibition of glucose transport induced AMPK (adenosine 5'-monophosphate-activated protein kinase)-dependent autophagy and regression of hepatic steatosis in vivo and a reduction in the accumulation of lipid droplets in primary murine hepatocyte cultures. Our data indicated that trehalose triggers beneficial cellular autophagy by inhibiting glucose transport.
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Affiliation(s)
- Brian J DeBosch
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Monique R Heitmeier
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Allyson L Mayer
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Cassandra B Higgins
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jan R Crowley
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Thomas E Kraft
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Maggie Chi
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth P Newberry
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zhouji Chen
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicholas O Davidson
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kevin E Yarasheski
- Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Paul W Hruz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kelle H Moley
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
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17
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Wolfer AM, Gaudin M, Taylor-Robinson SD, Holmes E, Nicholson JK. Development and Validation of a High-Throughput Ultrahigh-Performance Liquid Chromatography-Mass Spectrometry Approach for Screening of Oxylipins and Their Precursors. Anal Chem 2015; 87:11721-31. [PMID: 26501362 DOI: 10.1021/acs.analchem.5b02794] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Lipid mediators, highly bioactive compounds synthesized from polyunsaturated fatty acids (PUFAs), have a fundamental role in the initiation and signaling of the inflammatory response. Although extensively studied in isolation, only a limited number of analytical methods offer a comprehensive coverage of the oxylipin synthetic cascade applicable to a wide range of human biofluids. We report the development of an ultrahigh-performance liquid chromatography-electrospray ionization triple quadrupole mass spectrometry (UHPLC-MS) assay to quantify oxylipins and their PUFA precursors in 100 μL of human serum, plasma, urine, and cell culture supernatant. A single 15 min UHPLC run enables the quantification of 43 oxylipins and 5 PUFAs, covering pro and anti-inflammatory lipid mediators synthesized across the cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP450) pathways. The method was validated in multiple biofluid matrixes (serum, plasma, urine, and cell supernatant) and suppliers, ensuring its suitability for large scale metabonomic studies. The approach is accurate, precise, and reproducible (RSD < 15%) over multiple days and concentrations. Very high sensitivity is achieved with limits of quantification inferior to picograms for the majority of analytes (0.05-125 pg) and linear range spanning up to 5 orders of magnitude. This enabled the quantification of the great majority of these analytes at their low endogenous level in human biofluids. We successfully applied the procedure to individuals undergoing a fasting intervention; oxylipin profiles highlighted significantly altered PUFA and inflammatory profiles in accordance with previously published studies as well as offered new insight on the modulation of the biosynthetic cascade responsible for the regulation of oxylipins.
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Affiliation(s)
- Arnaud M Wolfer
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London , Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Mathieu Gaudin
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London , Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom
| | | | - Elaine Holmes
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London , Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom.,MRC-NIHR National Phenome Centre, Imperial College London , IRDB Building, Hammersmith Hospital, London W12 0NN, United Kingdom
| | - Jeremy K Nicholson
- Division of Computational and Systems Medicine, Department of Surgery and Cancer, Imperial College London , Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom.,MRC-NIHR National Phenome Centre, Imperial College London , IRDB Building, Hammersmith Hospital, London W12 0NN, United Kingdom
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18
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Palmitate-induced endothelial dysfunction is attenuated by cyanidin-3-O-glucoside through modulation of Nrf2/Bach1 and NF-κB pathways. Toxicol Lett 2015; 239:152-60. [PMID: 26422990 DOI: 10.1016/j.toxlet.2015.09.020] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 01/06/2023]
Abstract
Free fatty acids (FFA), commonly elevated in diabetes and obesity, have been shown to impair endothelial functions and cause oxidative stress, inflammation, and insulin resistance. Anthocyanins represent one of the most important and interesting classes of flavonoids and seem to play a role in preventing cardiovascular diseases. Herein, we investigated the in vitro protective effects of cyanidin-3-O-glucoside (C3G) on cell signaling pathways in human umbilical vein endothelial cells (HUVECs) exposed to palmitic acid (PA), the most prevalent saturated FFA in circulation. Our data reported a significant augmentation of free radicals and oxidative stress in HUVECs exposed to PA for 3h, while C3G pretreatment improved intracellular redox status altered by FFA. Moreover, C3G significantly inhibited NF-κB proinflammatory pathway and adhesion molecules induced by PA, and these effects were attributed to the activation of Nrf2/EpRE pathway. In fact, C3G induced Nrf2 nuclear localization and activation of cellular antioxidant and cytoprotective genes at baseline and after PA exposure in endothelial cells. Our data confirm the hypothesis that natural Nrf2 inducers, such as C3G, might be a potential therapeutic strategy to protect vascular system against various stressors preventing several pathological conditions.
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19
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Cohen G, Shamni O, Avrahami Y, Cohen O, Broner EC, Filippov-Levy N, Chatgilialoglu C, Ferreri C, Kaiser N, Sasson S. Beta cell response to nutrient overload involves phospholipid remodelling and lipid peroxidation. Diabetologia 2015; 58:1333-43. [PMID: 25810039 DOI: 10.1007/s00125-015-3566-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/11/2015] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Membrane phospholipids are the major intracellular source for fatty acid-derived mediators, which regulate myriad cell functions. We showed previously that high glucose levels triggered the hydrolysis of polyunsaturated fatty acids from beta cell phospholipids. These fatty acids were subjected to free radical-catalysed peroxidation to generate the bioactive aldehyde 4-hydroxy-2E-nonenal (4-HNE). The latter activated the nuclear peroxisome proliferator-activated receptor-δ (PPARδ), which in turn augmented glucose-stimulated insulin secretion. The present study aimed at investigating the combined effects of glucose and fatty acid overload on phospholipid turnover and the subsequent generation of lipid mediators, which affect insulin secretion and beta cell viability. METHODS INS-1E cells were incubated with increasing glucose concentrations (5-25 mmol/l) without or with palmitic acid (PA; 50-500 μmol/l) and taken for fatty acid-based lipidomic analysis and functional assays. Rat isolated islets of Langerhans were used similarly. RESULTS PA was incorporated into membrane phospholipids in a concentration- and time-dependent manner; incorporation was highest at 25 mmol/l glucose. This was coupled to a rapid exchange with saturated, mono-unsaturated and polyunsaturated fatty acids. Importantly, released arachidonic acid and linoleic acid were subjected to peroxidation, resulting in the generation of 4-HNE, which further augmented insulin secretion by activating PPARδ in beta cells. However, this adaptive increase in insulin secretion was abolished at high glucose and PA levels, which induced endoplasmic reticulum stress, apoptosis and cell death. CONCLUSIONS/INTERPRETATION These findings highlight a key role for phospholipid remodelling and fatty acid peroxidation in mediating adaptive and cytotoxic interactions induced by nutrient overload in beta cells.
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Affiliation(s)
- Guy Cohen
- Department of Pharmacology, Institute for Drug Research, Faculty of Medicine, The Hebrew University, Jerusalem, 9112102, Israel
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20
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Loss of Egr-1 sensitizes pancreatic β-cells to palmitate-induced ER stress and apoptosis. J Mol Med (Berl) 2015; 93:807-18. [DOI: 10.1007/s00109-015-1272-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/23/2015] [Accepted: 02/11/2015] [Indexed: 01/07/2023]
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21
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Mitochondrial fission mediates ceramide-induced metabolic disruption in skeletal muscle. Biochem J 2015; 456:427-39. [PMID: 24073738 DOI: 10.1042/bj20130807] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ceramide is a sphingolipid that serves as an important second messenger in an increasing number of stress-induced pathways. Ceramide has long been known to affect the mitochondria, altering both morphology and physiology. We sought to assess the impact of ceramide on skeletal muscle mitochondrial structure and function. A primary observation was the rapid and dramatic division of mitochondria in ceramide-treated cells. This effect is likely to be a result of increased Drp1 (dynamin-related protein 1) action, as ceramide increased Drp1 expression and Drp1 inhibition prevented ceramide-induced mitochondrial fission. Further, we found that ceramide treatment reduced mitochondrial O2 consumption (i.e. respiration) in cultured myotubes and permeabilized red gastrocnemius muscle fibre bundles. Ceramide treatment also increased H2O2 levels and reduced Akt/PKB (protein kinase B) phosphorylation in myotubes. However, inhibition of mitochondrial fission via Drp1 knockdown completely protected the myotubes and fibre bundles from ceramide-induced metabolic disruption, including maintained mitochondrial respiration, reduced H2O2 levels and unaffected insulin signalling. These data suggest that the forced and sustained mitochondrial fission that results from ceramide accrual may alter metabolic function in skeletal muscle, which is a prominent site not only of energy demand (via the mitochondria), but also of ceramide accrual with weight gain.
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22
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Hansen ME, Tippetts TS, Anderson MC, Holub ZE, Moulton ER, Swensen AC, Prince JT, Bikman BT. Insulin increases ceramide synthesis in skeletal muscle. J Diabetes Res 2014; 2014:765784. [PMID: 24949486 PMCID: PMC4052187 DOI: 10.1155/2014/765784] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/15/2014] [Accepted: 04/22/2014] [Indexed: 02/07/2023] Open
Abstract
AIMS The purpose of this study was to determine the effect of insulin on ceramide metabolism in skeletal muscle. METHODS Skeletal muscle cells were treated with insulin with or without palmitate for various time periods. Lipids (ceramides and TAG) were isolated and gene expression of multiple biosynthetic enzymes were quantified. Additionally, adult male mice received daily insulin injections for 14 days, followed by muscle ceramide analysis. RESULTS In muscle cells, insulin elicited an increase in ceramides comparable to palmitate alone. This is likely partly due to an insulin-induced increase in expression of multiple enzymes, particularly SPT2, which, when knocked down, prevented the increase in ceramides. In mice, 14 days of insulin injection resulted in increased soleus ceramides, but not TAG. However, insulin injections did significantly increase hepatic TAG compared with vehicle-injected animals. CONCLUSIONS This study suggests that insulin elicits an anabolic effect on sphingolipid metabolism in skeletal muscle, resulting in increased ceramide accumulation. These findings reveal a potential mechanism of the deleterious consequences of the hyperinsulinemia that accompanies insulin resistance and suggest a possible novel therapeutic target to mitigate its effects.
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Affiliation(s)
- M. E. Hansen
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - T. S. Tippetts
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - M. C. Anderson
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - Z. E. Holub
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - E. R. Moulton
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
| | - A. C. Swensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
| | - J. T. Prince
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
| | - B. T. Bikman
- Department of Physiology and Developmental Biology, 593 WIDB, Brigham Young University, Provo, UT 84602, USA
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23
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Khan S, Abu Jawdeh BG, Goel M, Schilling WP, Parker MD, Puchowicz MA, Yadav SP, Harris RC, El-Meanawy A, Hoshi M, Shinlapawittayatorn K, Deschênes I, Ficker E, Schelling JR. Lipotoxic disruption of NHE1 interaction with PI(4,5)P2 expedites proximal tubule apoptosis. J Clin Invest 2014; 124:1057-68. [PMID: 24531551 DOI: 10.1172/jci71863] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 12/11/2013] [Indexed: 12/12/2022] Open
Abstract
Chronic kidney disease progression can be predicted based on the degree of tubular atrophy, which is the result of proximal tubule apoptosis. The Na+/H+ exchanger NHE1 regulates proximal tubule cell survival through interaction with phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], but pathophysiologic triggers for NHE1 inactivation are unknown. Because glomerular injury permits proximal tubule luminal exposure and reabsorption of fatty acid/albumin complexes, we hypothesized that accumulation of amphipathic, long-chain acyl-CoA (LC-CoA) metabolites stimulates lipoapoptosis by competing with the structurally similar PI(4,5)P2 for NHE1 binding. Kidneys from mouse models of progressive, albuminuric kidney disease exhibited increased fatty acids, LC-CoAs, and caspase-2-dependent proximal tubule lipoapoptosis. LC-CoAs and the cytosolic domain of NHE1 directly interacted, with an affinity comparable to that of the PI(4,5)P2-NHE1 interaction, and competing LC-CoAs disrupted binding of the NHE1 cytosolic tail to PI(4,5)P2. Inhibition of LC-CoA catabolism reduced NHE1 activity and enhanced apoptosis, whereas inhibition of proximal tubule LC-CoA generation preserved NHE1 activity and protected against apoptosis. Our data indicate that albuminuria/lipiduria enhances lipotoxin delivery to the proximal tubule and accumulation of LC-CoAs contributes to tubular atrophy by severing the NHE1-PI(4,5)P2 interaction, thereby lowering the apoptotic threshold. Furthermore, these data suggest that NHE1 functions as a metabolic sensor for lipotoxicity.
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24
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Kampe K, Sieber J, Orellana JM, Mundel P, Jehle AW. Susceptibility of podocytes to palmitic acid is regulated by fatty acid oxidation and inversely depends on acetyl-CoA carboxylases 1 and 2. Am J Physiol Renal Physiol 2013; 306:F401-9. [PMID: 24338821 DOI: 10.1152/ajprenal.00454.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes is characterized by dyslipidemia with elevated free fatty acids (FFAs). Loss of podocytes is a hallmark of diabetic nephropathy, and podocytes are susceptible to saturated FFAs, which induce endoplasmic reticulum (ER) stress and podocyte death. Genome-wide association studies indicate that expression of acetyl-CoA carboxylase (ACC) 2, a key enzyme of fatty acid oxidation (FAO), is associated with proteinuria in type 2 diabetes. Here, we show that stimulation of FAO by aminoimidazole-4-carboxamide-1β-D-ribofuranoside (AICAR) or by adiponectin, activators of the low-energy sensor AMP-activated protein kinase (AMPK), protects from palmitic acid-induced podocyte death. Conversely, inhibition of carnitine palmitoyltransferase (CPT-1), the rate-limiting enzyme of FAO and downstream target of AMPK, augments palmitic acid toxicity and impedes the protective AICAR effect. Etomoxir blocked the AICAR-induced FAO measured with tritium-labeled palmitic acid. The beneficial effect of AICAR was associated with a reduction of ER stress, and it was markedly reduced in ACC-1/-2 double-silenced podocytes. In conclusion, the stimulation of FAO by modulating the AMPK-ACC-CPT-1 pathway may be part of a protective mechanism against saturated FFAs that drive podocyte death. Further studies are needed to investigate the potentially novel therapeutic implications of these findings.
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Affiliation(s)
- Kapil Kampe
- Dept. of Biomedicine, Molecular Nephrology, Rm. 303, Univ. Hospital Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
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Bolsoni-Lopes A, Festuccia WT, Farias TSM, Chimin P, Torres-Leal FL, Derogis PBM, de Andrade PB, Miyamoto S, Lima FB, Curi R, Alonso-Vale MIC. Palmitoleic acid (n-7) increases white adipocyte lipolysis and lipase content in a PPARα-dependent manner. Am J Physiol Endocrinol Metab 2013; 305:E1093-102. [PMID: 24022867 DOI: 10.1152/ajpendo.00082.2013] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated whether palmitoleic acid, a fatty acid that enhances whole body glucose disposal and suppresses hepatic steatosis, modulates triacylglycerol (TAG) metabolism in adipocytes. For this, both differentiated 3T3-L1 cells treated with either palmitoleic acid (16:1n7, 200 μM) or palmitic acid (16:0, 200 μM) for 24 h and primary adipocytes from wild-type or PPARα-deficient mice treated with 16:1n7 (300 mg·kg(-1)·day(-1)) or oleic acid (18:1n9, 300 mg·kg(-1)·day(-1)) by gavage for 10 days were evaluated for lipolysis, TAG, and glycerol 3-phosphate synthesis and gene and protein expression profile. Treatment of differentiated 3T3-L1 cells with 16:1n7, but not 16:0, increased basal and isoproterenol-stimulated lipolysis, mRNA levels of adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) and protein content of ATGL and pSer(660)-HSL. Such increase in lipolysis induced by 16:1n7, which can be prevented by pharmacological inhibition of PPARα, was associated with higher rates of PPARα binding to DNA. In contrast to lipolysis, both 16:1n7 and 16:0 increased fatty acid incorporation into TAG and glycerol 3-phosphate synthesis from glucose without affecting glyceroneogenesis and glycerokinase expression. Corroborating in vitro findings, treatment of wild-type but not PPARα-deficient mice with 16:1n7 increased primary adipocyte basal and stimulated lipolysis and ATGL and HSL mRNA levels. In contrast to lipolysis, however, 16:1n7 treatment increased fatty acid incorporation into TAG and glycerol 3-phosphate synthesis from glucose in both wild-type and PPARα-deficient mice. In conclusion, palmitoleic acid increases adipocyte lipolysis and lipases by a mechanism that requires a functional PPARα.
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Affiliation(s)
- Andressa Bolsoni-Lopes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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26
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Zhao M, Lamers Y, Ralat MA, Coats BS, Chi YY, Muller KE, Bain JR, Shankar MN, Newgard CB, Stacpoole PW, Gregory JF. Marginal vitamin B-6 deficiency decreases plasma (n-3) and (n-6) PUFA concentrations in healthy men and women. J Nutr 2012; 142:1791-7. [PMID: 22955512 PMCID: PMC3442793 DOI: 10.3945/jn.112.163246] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Previous animal studies showed that severe vitamin B-6 deficiency altered fatty acid profiles of tissue lipids, often with an increase of linoleic acid and a decrease of arachidonic acid. However, little is known about the extent to which vitamin B-6 deficiency affects human fatty acid profiles. The aim of this study was to determine the effects of marginal vitamin B-6 deficiency on fatty acid profiles in plasma, erythrocytes, and peripheral blood mononuclear cells (PBMC) of healthy adults fed a 28-d, low-vitamin B-6 diet. Healthy participants (n = 23) received a 2-d, controlled, vitamin B-6-adequate diet followed by a 28-d, vitamin B-6-restricted diet to induce a marginal deficiency. Plasma HDL and LDL cholesterol concentrations, FFA concentrations, and erythrocyte and PBMC membrane fatty acid compositions did not significantly change from baseline after the 28-d restriction. Plasma total arachidonic acid, EPA, and DHA concentrations decreased from (mean ± SD) 548 ± 96 to 490 ± 94 μmol/L, 37 ± 13 to 32 ± 13 μmol/L, and 121 ± 28 to 109 ± 28 μmol/L [positive false discovery rate (pFDR) adjusted P < 0.05], respectively. The total (n-6):(n-3) PUFA ratio in plasma exhibited a minor increase from 15.4 ± 2.8 to 16.6 ± 3.1 (pFDR adjusted P < 0.05). These data indicate that short-term vitamin B-6 restriction decreases plasma (n-3) and (n-6) PUFA concentrations and tends to increase the plasma (n-6):(n-3) PUFA ratio. Such changes in blood lipids may be associated with the elevated risk of cardiovascular disease in vitamin B-6 insufficiency.
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Affiliation(s)
- Mei Zhao
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences
| | - Yvonne Lamers
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences
| | - Maria A. Ralat
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences
| | - Bonnie S. Coats
- Division of Endocrinology and Metabolism, Department of Medicine, College of Medicine
| | | | | | - James R. Bain
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC
| | | | - Christopher B. Newgard
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC
| | - Peter W. Stacpoole
- Division of Endocrinology and Metabolism, Department of Medicine, College of Medicine,Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL; and
| | - Jesse F. Gregory
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences,To whom correspondence should be addressed. E-mail:
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Lupachyk S, Watcho P, Hasanova N, Julius U, G.Obrosova I. Triglyceride, nonesterified fatty acids, and prediabetic neuropathy: role for oxidative-nitrosative stress. Free Radic Biol Med 2012; 52:1255-63. [PMID: 22366714 PMCID: PMC3312982 DOI: 10.1016/j.freeradbiomed.2012.01.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/27/2012] [Accepted: 01/27/2012] [Indexed: 01/16/2023]
Abstract
Peripheral neuropathy develops in human subjects with prediabetes and metabolic syndrome before overt hyperglycemia. The contributions of impaired glucose tolerance and insulin signaling, hypertriglyceridemia and/or increased nonesterified fatty acids (NEFA), and hypercholesterolemia to this condition remain unknown. Niacin and its derivatives alleviate dyslipidemia with a minor effect on glucose homeostasis. This study evaluated the roles of impaired glucose tolerance versus dyslipidemia in prediabetic neuropathy using Zucker fatty (fa/fa) rats and the niacin derivative acipimox, as well as the interplay of hypertriglyceridemia, increased NEFA, and oxidative-nitrosative stress. Sixteen-week-old Zucker fatty rats with impaired glucose tolerance, obesity, hyperinsulinemia, hypertriglyceridemia, hypercholesterolemia, and increased NEFA displayed sensory nerve conduction velocity deficit, thermal and mechanical hypoalgesia, and tactile allodynia. Acipimox (100 mg kg(-1) day(-1), 4 weeks) reduced serum insulin, NEFA, and triglyceride concentrations without affecting glucose tolerance and hypercholesterolemia. It alleviated sensory nerve conduction velocity deficit and changes in behavioral measures of sensory function and corrected oxidative-nitrosative stress, but not impaired insulin signaling, in peripheral nerve. Elevated NEFA increased total and mitochondrial superoxide production and NAD(P)H oxidase activity in cultured human Schwann cells. In conclusion, hypertriglyceridemia and/or increased NEFA concentrations cause prediabetic neuropathy through oxidative-nitrosative stress. Lipid-lowering agents and antioxidants may find a use in the management of this condition.
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Affiliation(s)
- Sergey Lupachyk
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Pierre Watcho
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Nailia Hasanova
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
| | - Ulrich Julius
- University Hospital, Technical University of Dresden, Dresden Germany
| | - Irina G.Obrosova
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
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Mitochondrial fission contributes to mitochondrial dysfunction and insulin resistance in skeletal muscle. Mol Cell Biol 2011; 32:309-19. [PMID: 22083962 DOI: 10.1128/mcb.05603-11] [Citation(s) in RCA: 454] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial dysfunction in skeletal muscle has been implicated in the development of insulin resistance and type 2 diabetes. Considering the importance of mitochondrial dynamics in mitochondrial and cellular functions, we hypothesized that obesity and excess energy intake shift the balance of mitochondrial dynamics, further contributing to mitochondrial dysfunction and metabolic deterioration in skeletal muscle. First, we revealed that excess palmitate (PA), but not hyperglycemia, hyperinsulinemia, or elevated tumor necrosis factor alpha, induced mitochondrial fragmentation and increased mitochondrion-associated Drp1 and Fis1 in differentiated C2C12 muscle cells. This fragmentation was associated with increased oxidative stress, mitochondrial depolarization, loss of ATP production, and reduced insulin-stimulated glucose uptake. Both genetic and pharmacological inhibition of Drp1 attenuated PA-induced mitochondrial fragmentation, mitochondrial depolarization, and insulin resistance in C2C12 cells. Furthermore, we found smaller and shorter mitochondria and increased mitochondrial fission machinery in the skeletal muscle of mice with genetic obesity and those with diet-induced obesity. Inhibition of mitochondrial fission improved the muscle insulin signaling and systemic insulin sensitivity of obese mice. Our findings indicated that aberrant mitochondrial fission is causally associated with mitochondrial dysfunction and insulin resistance in skeletal muscle. Thus, disruption of mitochondrial dynamics may underlie the pathogenesis of muscle insulin resistance in obesity and type 2 diabetes.
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Therapeutic effect of Yunnan Baiyao on rheumatoid arthritis was partially due to regulating arachidonic acid metabolism in osteoblasts. J Pharm Biomed Anal 2011; 59:130-7. [PMID: 22075375 DOI: 10.1016/j.jpba.2011.10.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 10/17/2011] [Accepted: 10/17/2011] [Indexed: 11/23/2022]
Abstract
In order to explore the potential therapeutic effect of Yunnan Baiyao (YNB) on rheumatoid arthritis (RA), rat models were constructed and orally administrated with YNB or methotrexate (MTX) in parallel. Clinical physical, histological and biochemical parameters showed trivial therapeutic difference between YNB and MTX applications. Urine and serum metabonomics results indicated that many endogenous metabolites differentially changed among the rats receiving diverse therapeutic interventions. Among them, the fluctuation of arachidonic acid (AA) was thought to make sense. Thus, its relevant metabolites were subjected to quantitation by using osteoblasts treated by YNB in vitro. It was found that YNB extract of 20 μg/mL could greatly activate the synthesis of intracellular prostaglandin E₂ and thromboxane B₂ in osteoblasts. Excretion of prostaglandin D₂ could be suppressed but not the thromboxane B₂. This study proved the efficacy of YNB on curing RA and its potential mechanism through modulating AA metabolism in osteoblasts to some extent.
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Retamal MA, Evangelista-Martínez F, León-Paravic CG, Altenberg GA, Reuss L. Biphasic effect of linoleic acid on connexin 46 hemichannels. Pflugers Arch 2011; 461:635-43. [PMID: 21360038 PMCID: PMC3108795 DOI: 10.1007/s00424-011-0936-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 02/01/2011] [Accepted: 02/04/2011] [Indexed: 01/05/2023]
Abstract
Connexins form hemichannels at undocked plasma membranes and gap-junction channels (GJCs) at intercellular contacting zones. Under physiological conditions, hemichannels have low open probabilities, but their activation under pathological conditions, such as ischemia, induces and/or accelerates cell death. Connexin 46 (Cx46) is a major connexin of the lens, and mutations of this connexin induce cataracts. Here, we report the effects of linoleic acid (LA) on the electrical properties of Cx46 GJCs and hemichannels expressed in Xenopus laevis oocytes. LA has a biphasic effect, increasing hemichannel current at 0.1 μM and decreasing it at concentrations of 100 μM or higher. The effects of extracellular and microinjected LA conjugated to coenzyme A (LA-CoA) suggest that the current activation site is accessible from the intracellular but not extracellular compartment, whereas the current inhibitory site is either located in a region of the hemichannel pore inaccessible to intracellular LA-CoA, or requires crossing of LA through an organelle membrane. Experiments with other fatty acids demonstrated that the block of hemichannels depends on the presence of a hydrogenated double bond at position 9 and is directly proportional to the number of double bonds. Experiments in paired oocytes expressing Cx46 showed that LA does not affect GJCs. The block by unsaturated fatty acids reported here opens the possibility that increases in the concentration of these lipids in the lens induce cataract formation by blocking Cx46 hemichannels.
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Affiliation(s)
- Mauricio A Retamal
- Laboratorio de Fisiología, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile.
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31
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Lipid profile in Tunisian patients with rheumatoid arthritis. Clin Rheumatol 2011; 30:1325-31. [PMID: 21523363 DOI: 10.1007/s10067-011-1755-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 04/07/2011] [Accepted: 04/11/2011] [Indexed: 10/18/2022]
Abstract
This study aims to assess the prevalence of dyslipidaemia in Tunisian patients with active RA and to investigate the clinical and biological associated factors. A cross-sectional study was conducted on 92 unselected patients with active RA (77 females and 15 males, aged 49.1 ± 12.5 years) and 82 healthy subjects (68 females and 14 males, aged 50.8 ± 13.3 years). We recorded the patients' characteristics and the results of a lipid profile test (total cholesterol, TC; high-density lipoprotein cholesterol, HDL-c; low-density lipoprotein cholesterol, LDL-c; triglyceride, TG; lipoprotein (a), Lp (a); apolipoprotein A-1, apo A-1 and apolipoprotein B, apo B). In comparison to the control group, RA patients showed a higher prevalence of associated dyslipidaemia (95.7% versus 65.9% of cases, p < 0.001). Sera of patients showed higher TC (4.86 ± 1.07 versus 3.98 ± 0.73 mmol/L, p < 0.001), LDL-c (3.49 ± 0.98 versus 1.99 ± 0.62 mmol/L, p < 0.001), Lp (a) (288.04 ± 254.59 versus 187.94 ± 181.37 mmol/L, p = 0.004) and lower HDL-c (0.66 ± 0.24 versus 1.12 ± 0.3 mmol/L, p < 0.001). TC/HDL-c, LDL-c/HDL-c and non-HDL-c/HDL-c were also higher in RA patients; they were 8.24 ± 3.20 versus 3.76 ± 1.26 (p < 0.001), 5.91 ± 2.48 versus 1.92 ± 0.99 (p < 0.001) and 7.24 ± 3.20 versus 2.76 ± 1.26 (p < 0.001), respectively. Apo A-1 was correlated to Lp (a) (r = 0.291, p = 0.005). Corticoid dose was not associated to dyslipidaemia, but in multiple regression models, corticoid dose may be negatively related to some atherogenic markers, in particular non-HDL-c. Tunisian patients with markedly active RA experience substantially reduced serum HDL-c and increased TC, LDL-c and Lp (a) concentrations as well as increased TC/HDL-c, LDL-c/HDL-c and non-HDL-c/HDL-c ratios.
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Bilan PJ, Samokhvalov V, Koshkina A, Schertzer JD, Samaan MC, Klip A. Direct and macrophage-mediated actions of fatty acids causing insulin resistance in muscle cells. Arch Physiol Biochem 2009; 115:176-90. [PMID: 19671019 DOI: 10.1080/13813450903079314] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Obesity is associated with insulin resistance and increased risk for developing type 2 diabetes. Enlarged adipocytes develop resistance to the anti-lipolytic action of insulin. Elevated levels of fatty acids in the plasma and interstitial fluids lead to whole-body insulin resistance by disrupting normal insulin-regulated glucose uptake and glycogen storage in skeletal muscle. A new understanding has been cultivated in the past 5 to 10 years that adipocytes and macrophages (resident or bone marrow-derived) in adipose tissue of obese animals and humans are activated in a pro-inflammatory capacity and secrete insulin resistance-inducing factors. However, only recently have fatty acids themselves been identified as agents that engage toll-like receptors of the innate immunity systems of macrophages, adipocytes and muscle cells to trigger pro-inflammatory responses. This review summarizes our observations that fatty acids evoke the release of pro-inflammatory factors from macrophages that consequently induce insulin resistance in muscle cells.
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Affiliation(s)
- Phillip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, Canada
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Zeng L, Wu GZ, Goh KJ, Lee YM, Ng CC, You AB, Wang J, Jia D, Hao A, Yu Q, Li B. Saturated fatty acids modulate cell response to DNA damage: implication for their role in tumorigenesis. PLoS One 2008; 3:e2329. [PMID: 18523653 PMCID: PMC2402972 DOI: 10.1371/journal.pone.0002329] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 04/24/2008] [Indexed: 12/02/2022] Open
Abstract
DNA damage triggers a network of signaling events that leads to cell cycle arrest or apoptosis. This DNA damage response acts as a mechanism to prevent cancer development. It has been reported that fatty acids (FAs) synthesis is increased in many human tumors while inhibition of fatty acid synthase (FASN) could suppress tumor growth. Here we report that saturated fatty acids (SFAs) play a negative role in DNA damage response. Palmitic acid, as well as stearic acid and myristic acid, compromised the induction of p21 and Bax expression in response to double stranded breaks and ssDNA, while inhibition or knockdown of FASN enhanced these cellular events. SFAs appeared to regulate p21 and Bax expression via Atr-p53 dependent and independent pathways. These effects were only observed in primary mouse embryonic fibroblasts and osteoblasts, but not in immortalized murine NIH3T3, or transformed HCT116 and MCF-7 cell lines. Accordingly, SFAs showed some positive effects on proliferation of MEFs in response to DNA damage. These results suggest that SFAs, by negatively regulating the DNA damage response pathway, might promote cell transformation, and that increased synthesis of SFAs in precancer/cancer cells might contribute to tumor progression and drug resistance.
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Affiliation(s)
- Li Zeng
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Guang-Zhi Wu
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
- China-Japan Union Hospital, Jilin University, Changchun, Jilin, People's Republic of China
| | - Kim Jee Goh
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Yew Mun Lee
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Chuo Chung Ng
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Ang Ben You
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Jianhe Wang
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
| | - Deyong Jia
- The Key Laboratory of Experimental Teratology, Ministry of Education, Faculty of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Aijun Hao
- The Key Laboratory of Experimental Teratology, Ministry of Education, Faculty of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Qiang Yu
- Laboratory of Molecular Pharmacology, Genome Institute of Singapore, Singapore, Republic of Singapore
| | - Baojie Li
- Cancer and Developmental Biology Division, Institute of Molecular and Cell Biology, Singapore, Republic of Singapore
- * E-mail:
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Joshi-Barve S, Barve SS, Amancherla K, Gobejishvili L, Hill D, Cave M, Hote P, McClain CJ. Palmitic acid induces production of proinflammatory cytokine interleukin-8 from hepatocytes. Hepatology 2007; 46:823-30. [PMID: 17680645 DOI: 10.1002/hep.21752] [Citation(s) in RCA: 290] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED Obesity and the metabolic syndrome are closely correlated with hepatic steatosis. Simple hepatic steatosis in nonalcoholic fatty liver disease can progress to nonalcoholic steatohepatitis (NASH), which can be a precursor to more serious liver diseases, such as cirrhosis and hepatocellular carcinoma. The pathogenic mechanisms underlying progression of steatosis to NASH remain unclear; however, inflammation, proinflammatory cytokines, and oxidative stress have been postulated to play key roles. We previously reported that patients with NASH have elevated serum levels of proinflammatory cytokines, such as interleukin-8 (IL-8), which are likely to contribute to hepatic injury. This study specifically examines the effect of hepatic steatosis on IL-8 production. We induced lipid accumulation in hepatocytes (HepG2, rat primary hepatocytes, and human primary hepatocytes) by exposing them to pathophysiologically relevant concentrations of palmitic acid to simulate the excessive influx of fatty acids into hepatocytes. Significant fat accumulation was documented morphologically by Oil Red O staining in cells exposed to palmitic acid, and it was accompanied by an increase in intracellular triglyceride levels. Importantly, palmitic acid was found to induce significantly elevated levels of biologically active neutrophil chemoattractant, IL-8, from steatotic hepatocytes. Incubation of the cells with palmitate led to increased IL-8 gene expression and secretion (both mRNA and protein) through mechanisms involving activation of nuclear factor kappaB (NF-kappaB) and c-Jun N-terminal kinase/activator protein-1. CONCLUSION These data demonstrate for the first time that lipid accumulation in hepatocytes can stimulate IL-8 production, thereby potentially contributing to hepatic inflammation and consequent liver injury.
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Affiliation(s)
- Swati Joshi-Barve
- Department of Internal Medicine, the University of Louisville Medical Center, Louisville, KY 40292, USA
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Abstract
The aim of the present study was to investigate whether fasting for 24 and 48 h induces apoptosis of rat mesenteric lymph node lymphocytes similar to that observed previously in diabetic patients and alloxan-induced diabetic rats. Several features of lymphocyte death were evaluated by flow cytometry. Plasma levels of glucose, NEFAs (non-esterified fatty acids) and ketone bodies (acetoacetate and β-hydroxybutyrate) were determined in rats fasted for 24 and 48 h. Lymphocytes obtained from fasted rats had an increase in DNA fragmentation and phosphatidylserine externalization after 48 h of culture, although there was no loss of membrane integrity in lymphocytes even after 48 h of culture. Cytochrome c release from the mitochondrial intermembrane space into the cytosol was increased significantly in lymphocytes from fasted rats cultured for 24 h, whereas the levels of bcl-2 and bax proteins were not affected. Activities of caspases 3, 6, 8 and 9 were increased significantly in lymphocytes from rats fasted for 24 h, whereas only an increase in caspase 3 and 9 activities were observed in rats fasted for 48 h. In conclusion, fasting for 24 and 48 h caused a significant increase in the proportion of lymphocytes undergoing apoptosis. The occurrence of apoptosis was observed by DNA fragmentation, phosphatidylserine externalization, cytochrome c release from the mitochondria and activation of the caspase cascade. These findings support the hypothesis that conditions that raise plasma fatty acids levels (e.g. diabetes and starvation) may impair immune function by causing lymphocyte death.
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Affiliation(s)
- Juliana Pires
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1524, Butantan 05508-900, São Paulo, SP, Brazil
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Senn JJ. Toll-like receptor-2 is essential for the development of palmitate-induced insulin resistance in myotubes. J Biol Chem 2006; 281:26865-75. [PMID: 16798732 DOI: 10.1074/jbc.m513304200] [Citation(s) in RCA: 199] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fatty acids can activate proinflammatory pathways leading to the development of insulin resistance, but the mechanism is undiscovered. Toll like receptor 2 (TLR2) recognizes lipids, activates proinflammatory pathways, and is genetically associated with inflammatory diseases. This study aimed to examine the role of TLR2 in palmitate-induced insulin resistance in C2C12 myotubes. Treatment with palmitate rapidly induced the association of myeloid differentiation factor 88 (MyD88) with the TLR2 receptor, activated the stress-linked kinases p38, JNK, and protein kinase C, induced degradation of IkappaBalpha, and increased NF-kappaB DNA binding. The activation of these pathways by palmitate was sensitive and temporally regulated and occurred within the upper physiologic range of saturated fatty acid concentrations in vivo, suggesting a receptor-mediated event and not simple lipotoxicity. When compared with an equimolar concentration of palmitate, fibroblast-stimulating lipopeptide-1, a known TLR2 ligand, was a slightly more potent activator of signal transduction and interleukin (IL)-6 production. Palmitate inhibited insulin signal transduction in C2C12 cells beginning 1-2 h after exposure and reached a maximum at 12-16 h. An antagonist TLR2 antibody, mAb 2.5, led to a 50-60% decrease in palmitate-induced IL-6 production and partially restored insulin signal transduction, whereas an isotype-matched control antibody had no effect. RNA interference-mediated inhibition of TLR2 and MyD88 expression in C2C12 muscle cells resulted in a near complete inhibition of palmitate-induced insulin resistance and IL-6 production. This study provides strong evidence that TLR2 mediates the initial events of fatty acid-induced insulin resistance in muscle.
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Affiliation(s)
- Joseph J Senn
- Department of Pediatrics, Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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Haugen M, Fraser D, Forre O. Diet therapy for the patient with rheumatoid arthritis? Rheumatology (Oxford) 1999; 38:1039-44. [PMID: 10556253 DOI: 10.1093/rheumatology/38.11.1039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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