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Yuliana ME, Chou HC, Su ECY, Chuang HC, Huang LT, Chen CM. Uteroplacental insufficiency decreases leptin expression and impairs lung development in growth-restricted newborn rats. Pediatr Res 2024; 95:1503-1509. [PMID: 38049649 DOI: 10.1038/s41390-023-02946-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/16/2023] [Indexed: 12/06/2023]
Abstract
BACKGROUND The study aimed to analyze the effect of uteroplacental insufficiency (UPI) on leptin expression and lung development of intrauterine growth restriction (IUGR) rats. METHODS On day 17 of pregnancy, time-dated Sprague-Dawley rats were randomly divided into either an IUGR group or a control group. Uteroplacental insufficiency surgery (IUGR) and sham surgery (control) were conducted. Offspring rats were spontaneously delivered on day 22 of pregnancy. On postnatal days 0 and 7, rats' pups were selected at random from the control and IUGR groups. Blood was withdrawn from the heart to determine leptin levels. The right lung was obtained for leptin and leptin receptor levels, immunohistochemistry, proliferating cell nuclear antigen (PCNA), western blot, and metabolomic analyses. RESULTS UPI-induced IUGR decreased leptin expression and impaired lung development, causing decreased surface area and volume in offspring. This results in lower body weight, decreased serum leptin levels, lung leptin and leptin receptor levels, alveolar space, PCNA, and increased alveolar wall volume fraction in IUGR offspring rats. The IUGR group found significant relationships between serum leptin, radial alveolar count, von Willebrand Factor, and metabolites. CONCLUSION Leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment. IMPACT The neonatal rats with intrauterine growth restriction (IUGR) caused by uteroplacental insufficiency (UPI) showed decreased leptin expression and impaired lung development. UPI-induced IUGR significantly decreased surface area and volume in lung offspring. This is a novel study that investigates leptin expression and lung development in neonatal rats with IUGR caused by UPI. If our findings translate to IUGR infants, leptin may contribute to UPI-induced lung development during the postnatal period, suggesting supplementation as a potential treatment.
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Affiliation(s)
- Merryl Esther Yuliana
- International PhD Program in Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hsiu-Chu Chou
- Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Emily Chia-Yu Su
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Research Center for Artificial Intelligence in Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hsiao-Chi Chuang
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Liang-Ti Huang
- Department of Pediatrics, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chung-Ming Chen
- International PhD Program in Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan.
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Kumar AA, Satheesh G, Vijayakumar G, Chandran M, Prabhu PR, Simon L, Kutty VR, Kartha CC, Jaleel A. Plasma leptin level mirrors metabolome alterations in young adults. Metabolomics 2020; 16:87. [PMID: 32772182 DOI: 10.1007/s11306-020-01708-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 08/03/2020] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Leptin is known to regulate pathways of energy metabolism, reproduction, and control appetite. Whether plasma leptin levels reflect changes in metabolites of these pathways is unknown. OBJECTIVES We aimed to find whether there is an association between leptin levels and levels of metabolites of energy and hormone metabolism. METHODS We performed an untargeted metabolomics analysis of plasma from 110 healthy adults (men: women = 1:1; aged 18-40 years), using liquid chromatography-tandem mass spectrometry. Blood samples were collected from all the study subjects in the fasting state. Clinical features and markers of obesity and Type 2 diabetes mellitus (T2DM) were assessed in all. The association between levels of metabolites and clinical and biochemical parameters was identified using the multivariable-adjusted linear regression model and PLS-DA analysis. RESULTS The leptin level was found to have a significant association with a substantial number of metabolites in women and men. Leptin level was positively associated with glycocholic acid and arachidic acid, metabolites related to energy metabolisms, pregnanediol-3-glucuronide, a metabolite of progesterone metabolism, and quercetin 3'-sulfate, a diet-derived metabolite. Leptin level was negatively associated with ponasteroside A and barringtogenol C levels. Leptin level was positively correlated with adiponectin and negatively with total calorie intake and levels of triglyceride and very-low-density lipoprotein. Leptin levels were associated with lipid and sex hormone metabolism in women, while metabolites involved in amino acid metabolism were correlated to leptin in men. CONCLUSION Our study indicates that leptin level reflects metabolome alterations and hence could be a useful marker to detect early changes in energy and hormone metabolisms.
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Affiliation(s)
- A Aneesh Kumar
- Cardiovascular Diseases & Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India
- Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Gopika Satheesh
- Cardiovascular Diseases & Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India
| | - Gadadharan Vijayakumar
- Medical Trust Hospital and Diabetes Care Centre, Kulanada, Pathanamthitta, Kerala, India
| | - Mahesh Chandran
- Mass Spectrometry and Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India
| | - Priya R Prabhu
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India
| | - Leena Simon
- Medical Trust Hospital and Diabetes Care Centre, Kulanada, Pathanamthitta, Kerala, India
| | - Vellappillil Raman Kutty
- Achutha Menon Centre for Health Science Studies, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Thiruvananthapuram, Kerala, 695012, India
| | - Chandrasekharan C Kartha
- Society for Continuing Medical Education & Research, Kerala Institute of Medical Sciences, Thiruvananthapuram, Kerala, 695029, India
| | - Abdul Jaleel
- Cardiovascular Diseases & Diabetes Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India.
- Mass Spectrometry and Proteomics Core Facility, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, 695012, India.
- Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
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Sarabhai T, Kahl S, Szendroedi J, Markgraf DF, Zaharia OP, Barosa C, Herder C, Wickrath F, Bobrov P, Hwang JH, Jones JG, Roden M. Monounsaturated fat rapidly induces hepatic gluconeogenesis and whole-body insulin resistance. JCI Insight 2020; 5:134520. [PMID: 32434996 DOI: 10.1172/jci.insight.134520] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/09/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUNDWhile saturated fat intake leads to insulin resistance and nonalcoholic fatty liver, Mediterranean-like diets enriched in monounsaturated fatty acids (MUFA) may have beneficial effects. This study examined effects of MUFA on tissue-specific insulin sensitivity and energy metabolism.METHODSA randomized placebo-controlled cross-over study enrolled 16 glucose-tolerant volunteers to receive either oil (OIL, ~1.18 g/kg), rich in MUFA, or vehicle (VCL, water) on 2 occasions. Insulin sensitivity was assessed during preclamp and hyperinsulinemic-euglycemic clamp conditions. Ingestion of 2H2O/acetaminophen was combined with [6,6-2H2]glucose infusion and in vivo 13C/31P/1H/ex vivo 2H-magnet resonance spectroscopy to quantify hepatic glucose and energy fluxes.RESULTSOIL increased plasma triglycerides and oleic acid concentrations by 44% and 66% compared with VCL. Upon OIL intervention, preclamp hepatic and whole-body insulin sensitivity markedly decreased by 28% and 27%, respectively, along with 61% higher rates of hepatic gluconeogenesis and 32% lower rates of net glycogenolysis, while hepatic triglyceride and ATP concentrations did not differ from VCL. During insulin stimulation hepatic and whole-body insulin sensitivity were reduced by 21% and 25%, respectively, after OIL ingestion compared with that in controls.CONCLUSIONA single MUFA-load suffices to induce insulin resistance but affects neither hepatic triglycerides nor energy-rich phosphates. These data indicate that amount of ingested fat, rather than its composition, primarily determines the development of acute insulin resistance.TRIAL REGISTRATIONClinicalTrials.gov NCT01736202.FUNDINGGerman Diabetes Center, German Federal Ministry of Health, Ministry of Culture and Science of the state of North Rhine-Westphalia, German Federal Ministry of Education and Research, German Diabetes Association, German Center for Diabetes Research, Portugal Foundation for Science and Technology, European Regional Development Fund, and Rede Nacional de Ressonancia Magnética Nuclear.
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Affiliation(s)
- Theresia Sarabhai
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Sabine Kahl
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Daniel F Markgraf
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Oana-Patricia Zaharia
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Cristina Barosa
- Centre for Neurosciences and Cell Biology, UC Biotech, Cantanhede, Portugal.,Portuguese Diabetes Association, Lisbon, Portugal
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Frithjof Wickrath
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Pavel Bobrov
- German Center for Diabetes Research, München-Neuherberg, Germany.,Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jong-Hee Hwang
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - John Griffith Jones
- Centre for Neurosciences and Cell Biology, UC Biotech, Cantanhede, Portugal.,Portuguese Diabetes Association, Lisbon, Portugal
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany.,Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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Tan B, Li X, Wu G, Kong X, Liu Z, Li T, Yin Y. Dynamic changes in blood flow and oxygen consumption in the portal-drained viscera of growing pigs receiving acute administration of l-arginine. Amino Acids 2012; 43:2481-9. [DOI: 10.1007/s00726-012-1328-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 05/15/2012] [Indexed: 12/18/2022]
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Tan B, Li X, Yin Y, Wu Z, Liu C, Tekwe CD, Wu G. Regulatory roles for L-arginine in reducing white adipose tissue. FRONT BIOSCI-LANDMRK 2012; 17:2237-46. [PMID: 22652774 PMCID: PMC3422877 DOI: 10.2741/4047] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
As the nitrogenous precursor of nitric oxide, L-arginine regulates multiple metabolic pathways involved in the metabolism of fatty acids, glucose, amino acids, and proteins through cell signaling and gene expression. Specifically, arginine stimulates lipolysis and the expression of key genes responsible for activation of fatty acid oxidation to CO2 and water. The underlying mechanisms involve increases in the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha), mitochondrial biogenesis, and the growth of brown adipose tissue growth. Furthermore, arginine regulates adipocyte-muscle crosstalk and energy partitioning via the secretion of cytokines and hormones. In addition, arginine enhances AMP-activated protein kinase (AMPK) expression and activity, thereby modulating lipid metabolism and energy balance toward the loss of triacylglycerols. Growing evidence shows that dietary supplementation with arginine effectively reduces white adipose tissue in Zucker diabetic fatty rats, diet-induced obese rats, growing-finishing pigs, and obese patients with type II diabetes. Thus, arginine can be used to prevent and treat adiposity and the associated metabolic syndrome.
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Affiliation(s)
- Bi’e Tan
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
| | - Xinguo Li
- Hunan Institute of Animal Husbandry and Veterinary Medicine, Changsha, Hunan, China 410131
| | - Yulong Yin
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
| | - Zhenlong Wu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
| | - Chuang Liu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
| | - Carmen D. Tekwe
- Department of Statistics, Texas A and M University, College Station, TX, USA 77843-3143
| | - Guoyao Wu
- Research Center of Healthy Breeding of Livestock and Poultry and Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, the Chinese Academy of Sciences, Changsha, Hunan, China 410125
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193
- Department of Animal Science, Texas A&M University, College Station, TX, USA 77843-2471
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Tan B, Yin Y, Liu Z, Tang W, Xu H, Kong X, Li X, Yao K, Gu W, Smith SB, Wu G. Dietary l-arginine supplementation differentially regulates expression of lipid-metabolic genes in porcine adipose tissue and skeletal muscle. J Nutr Biochem 2011; 22:441-5. [DOI: 10.1016/j.jnutbio.2010.03.012] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 03/09/2010] [Accepted: 03/18/2010] [Indexed: 11/16/2022]
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7
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Harvey KA, Walker CL, Xu Z, Whitley P, Pavlina TM, Hise M, Zaloga GP, Siddiqui RA. Oleic acid inhibits stearic acid-induced inhibition of cell growth and pro-inflammatory responses in human aortic endothelial cells. J Lipid Res 2010; 51:3470-80. [PMID: 20852092 DOI: 10.1194/jlr.m010371] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Saturated fatty acids (SFAs), significant components of both enteral/parenteral nutritional formulations (including diet), are linked to cardiovascular disease complications, such as atherosclerosis. We investigated whether oleic acid (C18:1n-9) reduces the growth inhibitory and pro-inflammatory effects of the stearic acid (C18:0) in human aortic endothelial cells (HAEC). Stearic acid induced growth inhibition at concentrations less than 50 μM, whereas higher concentrations invoked cytotoxicity. Stearic acid-induced growth inhibition and cytotoxic effects were eradicated upon cosupplementation with oleic acid (25 μM). Oleic acid (as low as 5 μM) also inhibited the stearic acid-induced increase in intercellular adhesion molecule-1 (ICAM-1) expression. Stearic acid-induced phosphorylation of nuclear factor-kappa B (NF-κB), a transcriptional regulator of ICAM-1, was also reduced by oleic acid. HAECs supplemented with either stearic or oleic acid resulted in cellular incorporation of C18:0 and C18:1n-9, respectively. Stearic acid primarily incorporated into phospholipids without increasing the total fatty acid content in HAECs. In contrast, oleic acid, with or without stearic acid, incorporated into both phospholipids and triglycerides, with a significant increase in total fatty acid amounts in triglycerides. Our data suggest that oleic acid has the ability to reduce the inflammatory effects of long-chain SFAs in HAECs through reducing cellular stearic acid incorporation and NF-κB activation.
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Affiliation(s)
- Kevin A Harvey
- Cellular Biochemistry Laboratory, Methodist Research Institute, Indianapolis, IN, USA
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8
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Artwohl M, Lindenmair A, Roden M, Waldhäusl WK, Freudenthaler A, Klosner G, Ilhan A, Luger A, Baumgartner-Parzer SM. Fatty acids induce apoptosis in human smooth muscle cells depending on chain length, saturation, and duration of exposure. Atherosclerosis 2008; 202:351-62. [PMID: 18597758 DOI: 10.1016/j.atherosclerosis.2008.05.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Revised: 05/04/2008] [Accepted: 05/06/2008] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Plasma free fatty acid (FFA) concentrations are increased in states of insulin resistance. Therefore, this study evaluated apoptosis and underlying mechanisms induced by selected nutritional FFAs, a defined FFA-mix, and human plasma containing high FFA concentrations in human smooth muscle cells (HSMCs). RESEARCH DESIGN AND METHODS HSMCs were incubated (24-72 h) with selected FFAs (100-300 micromol/l), an FFA-mix (palmitic-/stearic-/oleic-/linoleic-/alpha-linolenic acid=2.6/1/3.6/9/1; 300-900 micromol/l), or with high FFA-plasma (600 micromol/l) versus respective control cultures. Apoptosis, caspase activation, and protein expression were determined by DNA-fragmentation assays, flow cytometry, and Western blots, respectively. RESULTS Exposure (24h) of HSMCs to 300 micromol/l stearic-, oleic-, linoleic-, alpha-linolenic-, and arachidonic acid induced apoptosis, correlating (p<0.01) with the FFAs' chain length (r=0.602) and number of FFA double bonds (r=0.956). After 48 h, 100 micromol/l of all tested FFAs - including palmitic acid - were already sufficient to trigger HSMCs' cell death. FFA-exposure resulted in activation of caspases and apoptosis was completely abolished by co-incubation with caspase inhibitors and negatively correlated (p<0.01) with the base-excision repair protein XRCC1 (r=-0.765) and with c-myc's antagonist mad (r=-0.916), whereas positive correlations (p<0.01) were found for protein expression of the proto-oncogene c-myc (r=0.972) and the transcription factor E2F-1 (r=0.971). Exposure of HSMCs to the defined FFA-mix and to plasma samples from individuals with elevated plasma FFAs supported the results obtained by defined FFA stimulation. CONCLUSIONS Since smooth muscle cells surround the macrophage/foam cell/lipid-laden artheromatous core of atherosclerotic lesions with a protective fibrous cap, their FFA-induced HSMC apoptosis could contribute to progression of atherosclerosis by thinning of the fibrous cap and subsequent plaque destabilization.
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Affiliation(s)
- Michaela Artwohl
- Department of Internal Medicine III, Clinical Division of Endocrinology and Metabolism, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
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9
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Artwohl M, Roden M, Waldhäusl W, Freudenthaler A, Baumgartner-Parzer SM. Free fatty acids trigger apoptosis and inhibit cell cycle progression in human vascular endothelial cells. FASEB J 2003; 18:146-8. [PMID: 14597560 DOI: 10.1096/fj.03-0301fje] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Plasma free fatty acid (FFA) concentrations are increased in states of insulin resistance and impair endothelial function. Because the underlying mechanisms are largely unknown, we examined selected, purified FFAs' (100-300 micromol/l, 24-48 h) action on apoptosis, cell cycle distribution, and associated gene/protein expression in human umbilical vein endothelial cells (HUVECs). Stearic acid, but not oleic acid, time and concentration dependently increased endothelial apoptosis by fivefold (n=6, P<0.01), whereas polyunsaturated FFAs (PUFAs; linoleic, gamma-linolenic, and arachidonic acid) exerted proapoptotic activity only at 300 micromol/l (P<0.05). Proapoptotic FFA action increased with FFAs' number of double bonds and with protein expression of the apoptosis promotor bak. The G0/G1 cell cycle arrest (n=6, P<0.05) induced by stearic acid (+14%) and PUFAs (+30%) is reflected by up-regulation of p21(WAF-1/Cip1). In addition, all FFAs concentration dependently reduced (P<0.05) gene/protein expression of clusterin (-54%), NF-kappaB's inhibitor, IkappaBalpha (-50%), endothelin-1 (-44%), and endothelial NO synthase (-44%). Plasma samples obtained from individuals with elevated plasma FFAs (372+/-22 micromol/l) increased endothelial apoptosis by 4.2-fold (P<0.001, n=10) compared with intra-individually matched low plasma FFA (56+/-21 micromol/l) conditions, underlining the results obtained by defined FFA stimulation. In conclusion, FFA structure differently affects endothelial cell proliferation and apoptosis, both representing key factors in the development of micro- and macrovascular dysfunction.
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Affiliation(s)
- Michaela Artwohl
- Department of Internal Medicine III, Division of Endocrinology and Metabolism, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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Kunert O, Stingl H, Rosian E, Krssák M, Bernroider E, Seebacher W, Zangger K, Staehr P, Chandramouli V, Landau BR, Nowotny P, Waldhäusl W, Haslinger E, Roden M. Measurement of fractional whole-body gluconeogenesis in humans from blood samples using 2H nuclear magnetic resonance spectroscopy. Diabetes 2003; 52:2475-82. [PMID: 14514629 DOI: 10.2337/diabetes.52.10.2475] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Several problems limit quantification of gluconeogenesis. We applied in vitro 2H-nuclear magnetic resonance (NMR) spectroscopy to simultaneously measure 2H in all glucose carbons for direct assessment of gluconeogenesis. This method was compared with 2H measurement in carbons 5 and 2 using gas chromatography-mass spectrometry (hexamethylenetetramine [HMT]) and with in vivo 13C magnetic resonance spectroscopy (MRS). After 14 h of fasting, and following 2H2O ingestion, blood was obtained from nine healthy and seven type 2 diabetic subjects. Glucose was purified, acetylated, and analyzed for 2H in carbons 1-6 with 2H-NMR. Using 5:2 ratios, gluconeogenesis increased (P < 0.05) over time and mean gluconeogenesis was lower in control subjects than in type 2 diabetic patients (63 +/- 3 vs. 75 +/- 2%, P < 0.01). 13C-MRS revealed higher hepatic glycogenolysis in control subjects (3.9 +/- 0.4 vs. 2.3 +/- 0.2 micromol.kg(-1).min(-1)) yielding mean contribution of gluconeogenesis of 65 +/- 3 and 77 +/- 2% (P < 0.005). Measurement of gluconeogenesis by 2H-NMR correlated linearly with 13C-MRS (r = 0.758, P = 0.0007) and HMT (r = 0.759, P = 0.0007). In an additional protocol, 2H enrichments demonstrated a fast decline of gluconeogenesis from approximately 100 to approximately 68% (P < 0.02) within 4 h of galactose infusion after 40-44 h of fasting. Thus, in vitro 2H-NMR offers an alternative approach to determine fractional gluconeogenesis in good agreement with standard methods and allows monitoring of rapid metabolic alterations.
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Affiliation(s)
- O Kunert
- Department of Pharmaceutical Chemistry, University of Graz, Graz, Austria
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11
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Cammisotto PG, Gélinas Y, Deshaies Y, Bukowiecki LJ. Regulation of leptin secretion from white adipocytes by free fatty acids. Am J Physiol Endocrinol Metab 2003; 285:E521-6. [PMID: 12736159 DOI: 10.1152/ajpendo.00052.2003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Norepinephrine stimulates lipolysis and concurrently inhibits insulin-stimulated leptin secretion from white adipocytes. To assess whether there is a cause-effect relationship between these two metabolic events, the effects of fatty acids were investigated in isolated rat adipocytes incubated in buffer containing low (0.1%) and high (4%) albumin concentrations. Palmitic acid (1 mM) mimicked the inhibitory effects of norepinephrine (1 microM) on insulin (10 nM)-stimulated leptin secretion, but only at low albumin concentrations. Studies investigating the effects of the chain length of saturated fatty acids [from butyric (C4) to stearic (C18) acids] revealed that only fatty acids with a chain length superior or equal to eight carbons effectively inhibited insulin-stimulated leptin secretion. Long-chain mono- and polyunsaturated fatty acids constitutively present in adipocyte triglyceride stores (oleic, linoleic, gamma-linolenic, palmitoleic, eicosapentanoic, and docosahexanoic acids) also completely suppressed leptin secretion. Saturated and unsaturated fatty acids inhibited insulin-stimulated leptin secretion with the same potency and without any significant effect on basal secretion. On the other hand, inhibitors of mitochondrial fatty acid oxidation (palmoxirate, 2-bromopalmitate, 2-bromocaproate) attenuated the stimulatory effects of insulin on leptin release without reversing the effects of fatty acids or norepinephrine, suggesting that fatty acids do not need to be oxidized by the mitochondria to inhibit leptin release. These results demonstrate that long-chain fatty acids mimic the effects of norepinephrine on leptin secretion and suggest that they may play a regulatory role as messengers between stimulation of lipolysis by norepinephrine and inhibition of leptin secretion.
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Affiliation(s)
- Philippe G Cammisotto
- Department of Anatomy and Physiology, Faculty of Medicine, Laval University, Quebec, Canada G1K 7P4
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