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Saraswathi V, Ai W, Kumar V, Sharma K, Gopal T, Kumar N, Malhi H, Sehrawat T, Desouza CV. A Pilot Study on the Proteomics Profile of Serum Exosome-Enriched Extracellular Vesicles from Normal versus Individuals with Obesity-Related Insulin Resistance. Biomedicines 2024; 12:799. [PMID: 38672154 PMCID: PMC11048419 DOI: 10.3390/biomedicines12040799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
OBJECTIVE Circulating exosome-enriched extracellular vesicles (EVs) have drawn considerable importance in obesity-related insulin-resistance (IR). We sought to compare the proteomics profile of serum exosomes from normal individuals and those with obesity and IR. METHODS We isolated serum exosomes from male subjects with obesity and insulin resistance (Ob-IR, HOMA-IR > 2.0) and lean/overweight insulin-sensitive (Normal (N), HOMA-IR < 2.0) individuals. The differential protein expression between the two groups was detected by a label-free quantitative mass spectrometry analysis followed by GO annotation and ingenuity pathway analysis (IPA). RESULTS We identified 23 upregulated and 46 downregulated proteins between Ob-IR and N groups. Some of these proteins are involved in altering insulin signaling (VPS13C, TBC1D32, TTR, and ADIPOQ), inflammation (NFκB and CRP), and B-cell proliferation/activation (IGLV4-69, IGKV1D-13, and IGHV4-28). GO analysis revealed that the differentially expressed proteins (DEPs) are mainly involved in regulating immune cell activation and are located in extracellular space. IPA analysis showed that top molecules mediating IR, inflammation and B-cell activation were upregulated in Ob-IR subjects compared to N subjects. CONCLUSIONS Serum exosomal proteins can be used as biomarkers to identify the future risk of diabetes and a therapeutic target to prevent or slow down the progression of diabetes in high-risk individuals.
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Affiliation(s)
- Viswanathan Saraswathi
- VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (V.S.); (W.A.); (T.G.); (N.K.)
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Weilun Ai
- VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (V.S.); (W.A.); (T.G.); (N.K.)
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Vikas Kumar
- Department of Genetics Cell Biology & Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA; (V.K.); (K.S.)
| | - Kanika Sharma
- Department of Genetics Cell Biology & Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA; (V.K.); (K.S.)
| | - Thiyagarajan Gopal
- VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (V.S.); (W.A.); (T.G.); (N.K.)
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Narendra Kumar
- VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (V.S.); (W.A.); (T.G.); (N.K.)
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Harmeet Malhi
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA (T.S.)
| | - Tejasav Sehrawat
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA (T.S.)
| | - Cyrus V. Desouza
- VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (V.S.); (W.A.); (T.G.); (N.K.)
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Brahadeeswaran S, Dasgupta T, Manickam V, Saraswathi V, Tamizhselvi R. NLRP3: a new therapeutic target in alcoholic liver disease. Front Immunol 2023; 14:1215333. [PMID: 37520548 PMCID: PMC10374212 DOI: 10.3389/fimmu.2023.1215333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 06/28/2023] [Indexed: 08/01/2023] Open
Abstract
The liver is in charge of a wide range of critical physiological processes and it plays an important role in activating the innate immune system which elicits the inflammatory events. Chronic ethanol exposure disrupts hepatic inflammatory mechanism and leads to the release of proinflammatory mediators such as chemokines, cytokines and activation of inflammasomes. The mechanism of liver fibrosis/cirrhosis involve activation of NLRP3 inflammasome, leading to the destruction of hepatocytes and subsequent metabolic dysregulation in humans. In addition, increasing evidence suggests that alcohol intake significantly modifies liver epigenetics, promoting the development of alcoholic liver disease (ALD). Epigenetic changes including histone modification, microRNA-induced genetic modulation, and DNA methylation are crucial in alcohol-evoked cell signaling that affects gene expression in the hepatic system. Though we are at the beginning stage without having the entire print of epigenetic signature, it is time to focus more on NLRP3 inflammasome and epigenetic modifications. Here we review the novel aspect of ALD pathology linking to inflammation and highlighting the role of epigenetic modification associated with NLRP3 inflammasome and how it could be a therapeutic target in ALD.
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Affiliation(s)
- Subhashini Brahadeeswaran
- Department of Biosciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Tiasha Dasgupta
- Department of Biosciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Venkatraman Manickam
- Department of Biosciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Viswanathan Saraswathi
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Veterans Affairs Medical Center, University of Nebraska Medical Center, Omaha, NE, United States
| | - Ramasamy Tamizhselvi
- Department of Biosciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
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Wade H, Pan K, Duan Q, Kaluzny S, Pandey E, Fatumoju L, Saraswathi V, Wu R, Harris EN, Su Q. Akkermansia muciniphila and its membrane protein ameliorates intestinal inflammatory stress and promotes epithelial wound healing via CREBH and miR-143/145. J Biomed Sci 2023; 30:38. [PMID: 37287024 DOI: 10.1186/s12929-023-00935-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 05/30/2023] [Indexed: 06/09/2023] Open
Abstract
BACKGROUND The intestinal epithelial barrier is the interface for interaction between gut microbiota and host metabolic systems. Akkermansia muciniphila (A. muciniphila) is a key player in the colonic microbiota that resides in the mucus layer, whose abundance is selectively decreased in the faecal microbiota of inflammatory bowel disease (IBD) patients. This study aims to investigate the regulatory mechanism among A. muciniphila, a transcription factor cAMP-responsive element-binding protein H (CREBH), and microRNA-143/145 (miR-143/145) in intestinal inflammatory stress, gut barrier integrity and epithelial regeneration. METHODS A novel mouse model with increased colonization of A muciniphila in the intestine of CREBH knockout mice, an epithelial wound healing assay and several molecular biological techniques were applied in this study. Results were analysed using a homoscedastic 2-tailed t-test. RESULTS Increased colonization of A. muciniphila in mouse gut enhanced expression of intestinal CREBH, which was associated with the mitigation of intestinal endoplasmic reticulum (ER) stress, gut barrier leakage and blood endotoxemia induced by dextran sulfate sodium (DSS). Genetic depletion of CREBH (CREBH-KO) significantly inhibited the expression of tight junction proteins that are associated with gut barrier integrity, including Claudin5 and Claudin8, but upregulated Claudin2, a tight junction protein that enhances gut permeability, resulting in intestinal hyperpermeability and inflammation. Upregulation of CREBH by A. muciniphila further coupled with miR-143/145 promoted intestinal epithelial cell (IEC) regeneration and wound repair via insulin-like growth factor (IGF) and IGFBP5 signalling. Moreover, the gene expressing an outer membrane protein of A. muciniphila, Amuc_1100, was cloned into a mammalian cell-expression vector and successfully expressed in porcine and human IECs. Expression of Amuc_1100 in IECs could recapitulate the health beneficial effect of A. muciniphila on the gut by activating CREBH, inhibiting ER stress and enhancing the expression of genes involved in gut barrier integrity and IEC's regeneration. CONCLUSIONS This study uncovers a novel mechanism that links A. muciniphila and its membrane protein with host CREBH, IGF signalling and miRNAs in mitigating intestinal inflammatory stress-gut barrier permeability and promoting intestinal wound healing. This novel finding may lend support to the development of therapeutic approaches for IBD by manipulating the interaction between host genes, gut bacteria and its bioactive components.
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Affiliation(s)
- Henry Wade
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Kaichao Pan
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, USA
| | - Qihua Duan
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Szczepan Kaluzny
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Ekta Pandey
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Linda Fatumoju
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | | | - Rongxue Wu
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, USA
| | - Edward N Harris
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Qiaozhu Su
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK.
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Kumar N, Rachagani S, Natarajan G, Crook A, Gopal T, Rajamanickam V, Kaushal JB, Nagabhishek SN, Powers R, Batra SK, Saraswathi V. Histidine Enhances the Anticancer Effect of Gemcitabine against Pancreatic Cancer via Disruption of Amino Acid Homeostasis and Oxidant-Antioxidant Balance. Cancers (Basel) 2023; 15:cancers15092593. [PMID: 37174059 PMCID: PMC10177467 DOI: 10.3390/cancers15092593] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Due to the severe toxicity posed by chemotherapeutic drugs, adjuvant nutritional intervention has gained increased attention in the treatment of pancreatic cancer (PC). Amino acid (AA) metabolism is aberrantly regulated in PC and circulating histidine (His) levels are low in PC patients. We hypothesized that His uptake and/or metabolism is dysregulated in PC and that combining His with gemcitabine (Gem), a drug used in the treatment of PC, will enhance the anti-cancer effects of Gem. We performed in vitro and in vivo studies to determine the anticancer effect of the combination of His and Gem against lethal PC. We demonstrate that circulating His levels are low in both human subjects and genetically engineered mice exhibiting pancreatic tumors. Interestingly, the expression of histidine ammonia lyase, an enzyme involved in His catabolism, is higher in PC compared to normal subjects. His + Gem exerts a more potent cytotoxic effect in PC cells compared to individual treatments. His treatment results in a profound increase in His accumulation, accompanied by a depletion of a number of AAs, promoting cancer cell survival and/or glutathione (GSH) synthesis. His but not Gem increases hydrogen peroxide and depletes cellular GSH. Supplementation with GSH protects cells against His + Gem-induced cytotoxicity. Further, our in vivo studies demonstrate that His + Gem potently reduced tumor mass and improved mouse survival. Taken together, our data suggest that PC cells exhibit an aberrant His uptake/accumulation which, in turn, leads to oxidative stress and depletion of AA pool, thereby enhancing the anticancer effect of Gem.
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Affiliation(s)
- Narendra Kumar
- The Department of Internal Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
- The VA Nebraska Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Satyanarayana Rachagani
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Gopalakrishnan Natarajan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Alexandra Crook
- The Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Thiyagarajan Gopal
- The Department of Internal Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
- The VA Nebraska Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Vinothkumar Rajamanickam
- The Department of Internal Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
- The VA Nebraska Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Jyoti B Kaushal
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Sirpu N Nagabhishek
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Robert Powers
- The Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Surinder K Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Viswanathan Saraswathi
- The Department of Internal Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Nebraska Medical Center, Omaha, NE 68198, USA
- The VA Nebraska Western Iowa Health Care System, Omaha, NE 68105, USA
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Saraswathi V, Vignesh S. EFFECT OF VAGAL NERVE STIMULATION AND JACOBSON RELAXATION TECHNIQUE ON AGORAPHOBIA AMONG POST NEUROLOGICAL ILL-PATIENTS. Psychiatr Danub 2023; 35:604-605. [PMID: 37992111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Affiliation(s)
- V Saraswathi
- Saveetha College of Physiotherapy, SIMATS, Chennai, Tamil Nadu, India
| | - S Vignesh
- Saveetha College of Physiotherapy, SIMATS, Chennai, Tamil Nadu, India
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Saraswathi V, Kumar N, Ai W, Gopal T, Bhatt S, Harris EN, Talmon GA, Desouza CV. Myristic Acid Supplementation Aggravates High Fat Diet-Induced Adipose Inflammation and Systemic Insulin Resistance in Mice. Biomolecules 2022; 12:739. [PMID: 35740864 PMCID: PMC9220168 DOI: 10.3390/biom12060739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 12/12/2022] Open
Abstract
Saturated fatty acids (SFAs) are considered to be detrimental to human health. One of the SFAs, myristic acid (MA), is known to exert a hypercholesterolemic effect in mice as well as humans. However, its effects on altering adipose tissue (AT) inflammation and systemic insulin resistance (IR) in obesity are still unclear. Here, we sought to determine the effects of a high fat (HF) diet supplemented with MA on obesity-associated metabolic disorders in mice. Wild-type C57BL/6 mice were fed a HF diet in the presence or absence of 3% MA for 12 weeks. Plasma lipids, plasma adipokines, AT inflammation, systemic IR, glucose homeostasis, and hepatic steatosis were assessed. The body weight and visceral adipose tissue (VAT) mass were significantly higher in mice receiving the HF+MA diet compared to HF diet-fed controls. Plasma total cholesterol levels were marginally increased in HF+MA-fed mice compared to controls. Fasting blood glucose was comparable between HF and HF+MA-fed mice. Interestingly, the plasma insulin and HOMA-IR index, a measure of insulin resistance, were significantly higher in HF+MA-fed mice compared to HF controls. Macrophage and inflammatory markers were significantly elevated in the AT and AT-derived stromal vascular cells upon MA feeding. Moreover, the level of circulating resistin, an adipokine promoting insulin resistance, was significantly higher in HF+MA-fed mice compared with HF controls. The insulin tolerance test revealed that the IR was higher in mice receiving the MA supplementation compared to HF controls. Moreover, the glucose tolerance test showed impairment in systemic glucose homeostasis in MA-fed mice. Analyses of liver samples showed a trend towards an increase in liver TG upon MA feeding. However, markers of oxidative stress and inflammation were reduced in the liver of mice fed an MA diet compared to controls. Taken together, our data suggest that chronic administration of MA in diet exacerbates obesity-associated insulin resistance and this effect is mediated in part, via increased AT inflammation and increased secretion of resistin.
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Affiliation(s)
- Viswanathan Saraswathi
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Narendra Kumar
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Weilun Ai
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Thiyagarajan Gopal
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Saumya Bhatt
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
| | - Edward N. Harris
- Department of Biochemistry, University of Nebraska, Lincoln, NE 68588, USA;
| | - Geoffrey A. Talmon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Cyrus V. Desouza
- Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; (N.K.); (W.A.); (T.G.); (S.B.); (C.V.D.)
- Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA
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Gopal T, Ai W, Casey CA, Donohue TM, Saraswathi V. A review of the role of ethanol-induced adipose tissue dysfunction in alcohol-associated liver disease. Alcohol Clin Exp Res 2021; 45:1927-1939. [PMID: 34558087 PMCID: PMC9153937 DOI: 10.1111/acer.14698] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022]
Abstract
Alcohol-associated liver disease (AALD) encompasses a spectrum of liver diseases that includes simple steatosis, steatohepatitis, fibrosis, and cirrhosis. The adverse effects of alcohol in liver and the mechanisms by which ethanol (EtOH) promotes liver injury are well studied. Although liver is known to be the primary organ affected by EtOH exposure, alcohol's effects on other organs are also known to contribute significantly to the development of liver injury. It is becoming increasingly evident that adipose tissue (AT) is an important site of EtOH action. Both AT storage and secretory functions are altered by EtOH. For example, AT lipolysis, stimulated by EtOH, contributes to chronic alcohol-induced hepatic steatosis. Adipocytes secrete a wide variety of biologically active molecules known as adipokines. EtOH alters the secretion of these adipokines from AT, which include cytokines and chemokines that exert paracrine effects in liver. In addition, the level of EtOH-metabolizing enzymes, in particular, CYP2E1, rises in the AT of EtOH-fed mice, which promotes oxidative stress and/or inflammation in AT. Thus, AT dysfunction characterized by increased AT lipolysis and free fatty acid mobilization and altered secretion of adipokines can contribute to the severity of AALD. Of note, moderate EtOH exposure results in AT browning and activation of brown adipose tissue which, in turn, can promote thermogenesis. In this review article, we discuss the direct effects of EtOH consumption in AT and the mechanisms by which EtOH impacts the functions of AT, which, in turn, increases the severity of AALD in animal models and humans.
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Affiliation(s)
- Thiyagarajan Gopal
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism
- VA Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Weilun Ai
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism
- VA Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Carol A. Casey
- Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE
- VA Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Terrence M. Donohue
- Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE
- VA Nebraska-Western Iowa Health Care System, Omaha, NE
| | - Viswanathan Saraswathi
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism
- VA Nebraska-Western Iowa Health Care System, Omaha, NE
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Thomes PG, Rasineni K, Saraswathi V, Kharbanda KK, Clemens DL, Sweeney SA, Kubik JL, Donohue TM, Casey CA. Natural Recovery by the Liver and Other Organs after Chronic Alcohol Use. Alcohol Res 2021; 41:05. [PMID: 33868869 PMCID: PMC8041137 DOI: 10.35946/arcr.v41.1.05] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Chronic, heavy alcohol consumption disrupts normal organ function and causes structural damage in virtually every tissue of the body. Current diagnostic terminology states that a person who drinks alcohol excessively has alcohol use disorder. The liver is especially susceptible to alcohol-induced damage. This review summarizes and describes the effects of chronic alcohol use not only on the liver, but also on other selected organs and systems affected by continual heavy drinking—including the gastrointestinal tract, pancreas, heart, and bone. Most significantly, the recovery process after cessation of alcohol consumption (abstinence) is explored. Depending on the organ and whether there is relapse, functional recovery is possible. Even after years of heavy alcohol use, the liver has a remarkable regenerative capacity and, following alcohol removal, can recover a significant portion of its original mass and function. Other organs show recovery after abstinence as well. Data on studies of both heavy alcohol use among humans and animal models of chronic ethanol feeding are discussed. This review describes how (or whether) each organ/tissue metabolizes ethanol, as metabolism influences the organ’s degree of injury. Damage sustained by the organ/tissue is reviewed, and evidence for recovery during abstinence is presented.
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Affiliation(s)
- Paul G Thomes
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Karuna Rasineni
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Viswanathan Saraswathi
- Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska.,Department of Internal Medicine, Section of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska
| | - Kusum K Kharbanda
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Dahn L Clemens
- Department of Internal Medicine, Section of Cardiovascular Medicine, University of Nebraska Medical Center, Omaha, Nebraska.,Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska
| | - Sarah A Sweeney
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Jacy L Kubik
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Terrence M Donohue
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Carol A Casey
- Department of Internal Medicine, Section of Gastroenterology, University of Nebraska Medical Center, Omaha, Nebraska.,Research Service, U.S. Department of Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
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Gopal T, Kumar N, Perriotte-Olson C, Casey CA, Donohue TM, Harris EN, Talmon G, Kabanov AV, Saraswathi V. Nanoformulated SOD1 ameliorates the combined NASH and alcohol-associated liver disease partly via regulating CYP2E1 expression in adipose tissue and liver. Am J Physiol Gastrointest Liver Physiol 2020; 318:G428-G438. [PMID: 31928222 PMCID: PMC7099493 DOI: 10.1152/ajpgi.00217.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Enhanced free fatty acid (FFA) flux from adipose tissue (AT) to liver plays an important role in the development of nonalcoholic steatohepatitis (NASH) and alcohol-associated liver disease (AALD). We determined the effectiveness of nanoformulated superoxide dismutase 1 (Nano) in attenuating liver injury in a mouse model exhibiting a combination of NASH and AALD. Male C57BL6/J mice were fed a chow diet (CD) or a high-fat diet (HF) for 10 wk followed by pair feeding of the Lieber-DeCarli control (control) or ethanol (ET) diet for 4 wk. Nano was administered once every other day for the last 2 wk of ET feeding. Mice were divided into 1) CD + control diet (CD + Cont), 2) high-fat diet (HF) + control diet (HF + Cont), 3) HF + Cont + Nano, 4) HF + ET diet (HF + ET), and 5) HF + ET + Nano. The total fat mass, visceral AT mass (VAT), and VAT perilipin 1 content were significantly lower only in HF + ET-fed mice but not in HF + ET + Nano-treated mice compared with controls. The HF + ET-fed mice showed an upregulation of VAT CYP2E1 protein, and Nano abrogated this effect. We noted a significant rise in plasma FFAs, ALT, and monocyte chemoattractant protein-1 in HF + ET-fed mice, which was blunted in HF + ET + Nano-treated mice. HF + ET-induced increases in hepatic steatosis and inflammatory markers were attenuated upon Nano treatment. Nano reduced hepatic CYP2E1 and enhanced catalase levels in HF + ET-fed mice with a concomitant increase in SOD1 protein and activity in liver. Nano was effective in attenuating AT and liver injury in mice exhibiting a combination of NASH and AALD, partly via reduced CYP2E1-mediated ET metabolism in these organs.NEW & NOTEWORTHY Increased free fatty acid flux from adipose tissue (AT) to liver accompanied by oxidative stress promotes nonalcoholic steatohepatitis (NASH) and alcohol-associated liver injury (AALD). Obesity increases the severity of AALD. Using a two-hit model involving a high-fat diet and chronic ethanol feeding to mice, and treating them with nanoformulated superoxide dismutase (nanoSOD), we have shown that nanoSOD improves AT lipid storage, reduces CYP2E1 in AT and liver, and attenuates the combined NASH/AALD in mice.
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Affiliation(s)
- Thiyagarajan Gopal
- 1Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Narendra Kumar
- 1Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Curtis Perriotte-Olson
- 1Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska
| | - Carol A. Casey
- 2Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska,3Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Terrence M. Donohue
- 2Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska,3Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Edward N. Harris
- 4Department of Biochemistry, University of Nebraska Lincoln, Lincoln, Nebraska
| | - Geoffrey Talmon
- 5Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Alexander V. Kabanov
- 6Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina
| | - Viswanathan Saraswathi
- 1Division of Diabetes, Endocrinology, and Metabolism, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska,3Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
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Saraswathi V, Heineman R, Alnouti Y, Shivaswamy V, Desouza CV. A combination of Omega-3 PUFAs and COX inhibitors: A novel strategy to manage obesity-linked dyslipidemia and adipose tissue inflammation. J Diabetes Complications 2020; 34:107494. [PMID: 31787562 DOI: 10.1016/j.jdiacomp.2019.107494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 01/30/2023]
Abstract
We previously reported that fish oil in combination with cyclooxygenase (COX) inhibitors exerts enhanced hypolipidemic and anti-inflammatory effects in mice. Here, we sought to determine the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in combination with naproxen (NX), a COX inhibitor, on dyslipidemia and gene expression in adipose tissue (AT) in humans. Obese dyslipidemic patients were randomly assigned to one of these interventions for 12 wk: 1) Standard nutrition counseling (control), 2) ω-3 PUFAs (2 g twice daily), 3) NX (220 mg twice daily), and 4) ω-3 PUFAs (2 g twice daily) + NX (220 mg twice daily). The serum triglycerides showed a trend towards a reduction and a significant reduction (P<0.05) in ω-3 and ω3 + NX-treated subjects, respectively, compared to control. The mRNA expression of vascular cell adhesion molecule-1 (Vcam1), an inflammatory marker, increased significantly in AT of ω-3 PUFA-treated subjects but not in ω-3 PUFAs+NX-treated group. The plasma level of glycine-conjugated hyodeoxycholic acid, a secondary bile acid with hypolipidemic property, increased significantly in ω-3 PUFAs + NX-treated group. Our data suggest that combining NX with ω-3 PUFAs increases their effectiveness in reducing serum TG and favorably altering AT gene expression and plasma bile acid profile.
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Affiliation(s)
- Viswanathan Saraswathi
- Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, United States of America; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States of America
| | - Robert Heineman
- Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, United States of America; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States of America
| | - Yazen Alnouti
- Pharmaceutical Sciences, University of Nebraska Medical Center, United States of America
| | - Vijay Shivaswamy
- Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, United States of America; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States of America
| | - Cyrus V Desouza
- Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, United States of America; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States of America.
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Natarajan G, Perriotte-Olson C, Casey CA, Donohue TM, Talmon GA, Harris EN, Kabanov AV, Saraswathi V. Effect of nanoformulated copper/zinc superoxide dismutase on chronic ethanol-induced alterations in liver and adipose tissue. Alcohol 2019; 79:71-79. [PMID: 30611703 DOI: 10.1016/j.alcohol.2018.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 12/22/2018] [Accepted: 12/28/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND We previously reported that nanoformulated copper/zinc superoxide dismutase (Nano) attenuates non-alcoholic fatty liver disease and adipose tissue (AT) inflammation in obese animals. Here, we sought to determine whether Nano treatment attenuates alcohol-associated liver disease (AALD) and AT inflammation in alcohol-fed mice. METHODS We pre-treated E-47 cells (HepG2 cells that over-express CYP2E1) with native- or nano-superoxide dismutase (SOD) for 6 h, followed by treatment with ethanol and/or linoleic acid (LA), a free fatty acid. For in vivo studies, male C57BL/6 mice were fed the Lieber-DeCarli control or ethanol liquid diet for 4 weeks. The mice received Nano once every 2 days during the last 2 weeks of ethanol feeding. RESULTS Our in vitro studies revealed that Nano pretreatment reduced LA + ethanol-induced oxidative stress in E-47 cells. Our in vivo experiments showed that ethanol-fed Nano-treated mice had 22% lower hepatic triglyceride levels than mice fed ethanol alone. Nano-treated ethanol-fed mice also had 2-fold lower levels of Cd68 and similarly reduced levels of Ccl2 and Mmp12 mRNAs, than in untreated ethanol-fed mice. We also noted that ethanol feeding caused a remarkable increase in hepatic and/or plasma MCP-1 and CCR2 protein, which was blunted in ethanol + Nano-treated animals. The hepatic content of SREBP-1c, a transcription factor that promotes lipogenesis, was higher in ethanol-fed mice than controls but was attenuated in ethanol + Nano-treated animals. Further, livers of ethanol + Nano-treated mice had significantly higher levels of phosphorylated adenosine monophosphate-activated protein kinase (AMPK) than both control and ethanol-fed mice. In AT, the levels of Il6 mRNA, a hepatoprotective cytokine, and that of Arg1, a marker of anti-inflammatory macrophages, were significantly increased in ethanol + Nano-treated mice compared with control mice. CONCLUSION Our data indicate that Nano treatment attenuates ethanol-induced steatohepatitis and that this effect is associated with an apparent activation of AMPK signaling. Our data also suggest that Nano induces Arg1 and Il6 expression in AT, suggesting anti-inflammatory effects in this tissue.
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Affiliation(s)
- Gopalakrishnan Natarajan
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, United States
| | - Curtis Perriotte-Olson
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, United States
| | - Carol A Casey
- Department of Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE, United States; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States
| | - Terrence M Donohue
- Department of Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE, United States; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States
| | - Geoffrey A Talmon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Edward N Harris
- Department of Biochemistry, University of Nebraska at Lincoln, Lincoln, NE, United States
| | - Alexander V Kabanov
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Viswanathan Saraswathi
- Department of Internal Medicine, Divisions of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, United States; VA Nebraska-Western Iowa Health Care System, Omaha, NE, United States.
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12
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Pothuraju R, Rachagani S, Junker WM, Chaudhary S, Saraswathi V, Kaur S, Batra SK. Pancreatic cancer associated with obesity and diabetes: an alternative approach for its targeting. J Exp Clin Cancer Res 2018; 37:319. [PMID: 30567565 PMCID: PMC6299603 DOI: 10.1186/s13046-018-0963-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/14/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Pancreatic cancer (PC) is among foremost causes of cancer related deaths worldwide due to generic symptoms, lack of effective screening strategies and resistance to chemo- and radiotherapies. The risk factors associated with PC include several metabolic disorders such as obesity, insulin resistance and type 2 diabetes mellitus (T2DM). Studies have shown that obesity and T2DM are associated with PC pathogenesis; however, their role in PC initiation and development remains obscure. MAIN BODY Several biochemical and physiological factors associated with obesity and/or T2DM including adipokines, inflammatory mediators, and altered microbiome are involved in PC progression and metastasis albeit by different molecular mechanisms. Deep understanding of these factors and causal relationship between factors and altered signaling pathways will facilitate deconvolution of disease complexity as well as lead to development of novel therapies. In the present review, we focuses on the interplay between adipocytokines, gut microbiota, adrenomedullin, hyaluronan, vanin and matrix metalloproteinase affected by metabolic alteration and pancreatic tumor progression. CONCLUSIONS Metabolic diseases, such as obesity and T2DM, contribute PC development through altered metabolic pathways. Delineating key players in oncogenic development in pancreas due to metabolic disorder could be a beneficial strategy to combat cancers associated with metabolic diseases in particular, PC.
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Affiliation(s)
- Ramesh Pothuraju
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Satyanarayana Rachagani
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Wade M Junker
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.,Sanguine Diagnostics and Therapeutics, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sanjib Chaudhary
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Viswanathan Saraswathi
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Sukhwinder Kaur
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Surinder K Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA. .,Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA. .,Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA.
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13
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Natarajan G, Perriotte-Olson C, Bhinderwala F, Powers R, Desouza CV, Talmon GA, Yuhang J, Zimmerman MC, Kabanov AV, Saraswathi V. Nanoformulated copper/zinc superoxide dismutase exerts differential effects on glucose vs lipid homeostasis depending on the diet composition possibly via altered AMPK signaling. Transl Res 2017; 188:10-26. [PMID: 28867395 PMCID: PMC5819896 DOI: 10.1016/j.trsl.2017.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 12/17/2022]
Abstract
Evidence suggests that superoxide dismutase 1 (SOD1) promotes glucose vs lipid metabolism depending on the diet type. We recently reported that nanoformulated SOD1 (Nano) improved lipid metabolism without altering glucose homeostasis in high-fat (HF) diet-fed mice. Here, we sought to determine the effects and potential mechanisms of Nano in modulating glucose and lipid homeostasis in mice fed a normal chow diet (CD) vs HF diet. Mice were fed a CD or a HF diet (45%) for 10 wk and injected with Nano once every 2 days for 15 days. The fasting glucose level was lower (P < 0.05) in CD + Nano-treated mice compared to control. Conversely, blood glucose was not altered but serum triglycerides were lower in HF + Nano-treated mice. Genes involved in fatty acid synthesis were reduced by Nano in the skeletal muscle of CD but not of HF diet-fed mice. Adenosine monophosphate-activated protein kinase (AMPK), which promotes both glucose and lipid metabolism depending on the fuel availability, is activated by Nano in CD-fed mice. Moreover, Nano increased phosphorylation of ACC, a downstream target of AMPK, in both CD and HF diet-fed mice. Nano increased mitochondrial respiration in C2C12 myocytes in the presence of glucose or fatty acid, and this effect is inhibited by Compound C, an AMPK inhibitor. Our data suggest that Nano promotes glucose and lipid metabolism in CD and HF diet-fed mice, respectively, and this effect is mediated partly via AMPK signaling.
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Affiliation(s)
- Gopalakrishnan Natarajan
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Neb
| | - Curtis Perriotte-Olson
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Neb
| | - Fatema Bhinderwala
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Neb; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Neb
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Neb; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, Neb
| | - Cyrus V Desouza
- VA Nebraska-Western Iowa Health Care System, Omaha, Neb; Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Neb
| | - Geoffrey A Talmon
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Neb
| | - Jiang Yuhang
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Matthew C Zimmerman
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Neb
| | - Alexander V Kabanov
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Viswanathan Saraswathi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Neb; VA Nebraska-Western Iowa Health Care System, Omaha, Neb.
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Saraswathi V, Perriotte-Olson C, Ganesan M, Desouza CV, Alnouti Y, Duryee MJ, Thiele GM, Nordgren TM, Clemens DL. A combination of dietary N-3 fatty acids and a cyclooxygenase-1 inhibitor attenuates nonalcoholic fatty liver disease in mice. J Nutr Biochem 2017; 42:149-159. [PMID: 28187366 DOI: 10.1016/j.jnutbio.2017.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/13/2016] [Accepted: 01/19/2017] [Indexed: 12/12/2022]
Abstract
We sought to determine whether a combination of purified n-3 fatty acids (n-3) and SC-560 (SC), a cyclooxygenase-1-specific inhibitor, is effective in ameliorating nonalcoholic fatty liver disease in obesity. Female wild-type mice were fed a high-fat and high-cholesterol diet (HF) supplemented with n-3 in the presence or absence of SC. Mice treated with SC alone exhibited no change in liver lipids, whereas n-3-fed mice tended to have lower hepatic lipids. Mice given n-3+SC had significantly lower liver lipids compared with HF controls indicating enhanced lipid clearance. Total and sulfated bile acids were significantly higher only in n-3+SC-treated mice compared with chow diet (CD) controls. Regarding mechanisms, the level of pregnane X receptor (PXR), a nuclear receptor regulating drug/bile detoxification, was significantly higher in mice given n-3 or n-3+SC. Studies in precision-cut liver slices and in cultured hepatoma cells showed that n-3+SC enhanced not only the expression/activation of PXR and its target genes but also the expression of farnesoid X receptor (FXR), another regulator of bile synthesis/clearance, indicating that n-3+SC can induce both PXR and FXR. The mRNA level of FGFR4 which inhibits bile formation showed a significant reduction in Huh 7 cells upon n-3 and n-3+SC treatment. PXR overexpression in hepatoma cells confirmed that n-3 or SC each induced the expression of PXR target genes and in combination had an enhanced effect. Our findings suggest that combining SC with n-3 potentiates its lipid-lowering effect, in part, by enhanced PXR and/or altered FXR/FGFR4 signaling.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Curtis Perriotte-Olson
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA
| | - Murali Ganesan
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA
| | - Cyrus V Desouza
- Department of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - Yazen Alnouti
- Department of Pharmaceutical Science, University of Nebraska Medical Center, Omaha, NE, USA
| | - Michael J Duryee
- Department of Internal Medicine, Division of Rheumatology and Immunology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Geoffrey M Thiele
- Department of Pharmaceutical Science, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - Tara M Nordgren
- Department of Internal Medicine, Division of Pulmonary, Critical Care, Sleep, and Allergy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Dahn L Clemens
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
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Saraswathi V, Perriotte-Olson C, Natarajan G, Desouza CV. ID: 80: IMPACT OF CYCLOOXYGENASE-2 DELETION ON ADIPOSE TISSUE INFLAMMATION AND SYSTEMIC METABOLIC HOMEOSTASIS IN OBESITY. J Investig Med 2016. [DOI: 10.1136/jim-2016-000120.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
ObjectiveAdipose tissue (AT) inflammation characterized by macrophage accumulation and secretion of inflammatory mediators is considered to play a critical role in the pathogenesis of obesity-linked metabolic disorders, in particular, insulin resistance. Although an intimate relationship exists between inflammation and metabolism, there is a lack of consistent therapeutic success in targeting inflammatory pathways to treat obesity-linked metabolic diseases suggesting that certain immunoregulatory genes can exert differential effects on metabolic regulation. The objective of this study is to determine the role of cyclooxygenase-2 (COX-2), an inducible inflammatory gene, abundantly upregulated in macrophages upon exposure to inflammatory stimuli, in modulating AT inflammation and systemic metabolic homeostasis in obesity.MethodsWild type (WT) and COX-2 knock-out (COX-2-/-) mice were fed a standard chow diet (CD) or a high fat (HF, 45% fat calories) diet for 13 wk. The expression of macrophage and inflammatory markers were determined in visceral AT and macrophage-rich stromal cells collected from visceral AT. In addition, various metabolic tests including insulin and glucose tolerance tests and energy expenditure measurements were performed to determine the impact of COX-2 deletion in modulating metabolic homeostasis.ResultsConsistent with its role in inducing an inflammatory response, deletion of COX-2 resulted in a decrease in markers of AT inflammation. For example, the markers of M1 pro-inflammatory macrophages were reduced and that of M2 anti-inflammatory macrophages were increased in the visceral AT of COX-2−/− compared to WT mice on a HF diet. Moreover, the mRNA expression of inflammatory genes such as MIP1α and TNFα was significantly lower (P<0.05) in COX-2−/− compared to WT mice. Although AT inflammation was reduced, COX-2 deletion led to impaired metabolic homeostasis. Notably, the total fat mass determined by EchoMRI was significantly higher (P<0.001) with a concomitant increase in visceral AT mass and plasma leptin levels (P<0.05) in COX-2−/− mice. In addition, the plasma total cholesterol was significantly higher (P<0.05) in COX-2−/− compared to WT mice on a HF diet. Moreover, COX-2−/− mice exhibit systemic insulin resistance and impaired glucose handling as analyzed by insulin and glucose tolerance tests. Further, the energy expenditure and locomotor activity determined using the metabolic cages were greatly reduced in COX-2−/− compared to WT mice.ConclusionTaken together, deletion of COX-2 attenuated AT inflammation but increased adiposity and impaired metabolic homeostasis in a state of nutrient excess. Although inflammation is intricately linked to metabolism, our study suggests that a considerable discordance exists between these two processes and that COX-2 derived eicosanoids can exert differential effects in modulating inflammatory and metabolic processes.
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Perriotte-Olson C, Adi N, Manickam DS, Westwood RA, Desouza CV, Natarajan G, Crook A, Kabanov AV, Saraswathi V. Nanoformulated copper/zinc superoxide dismutase reduces adipose inflammation in obesity. Obesity (Silver Spring) 2016; 24:148-56. [PMID: 26612356 PMCID: PMC6699510 DOI: 10.1002/oby.21348] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/20/2015] [Accepted: 08/26/2015] [Indexed: 12/17/2022]
Abstract
OBJECTIVE An intimate association exists between oxidative stress and inflammation. Because adipose tissue (AT) inflammation is intricately linked to metabolic disorders, it was hypothesized that reducing oxidative stress would be effective in ameliorating AT inflammation in obesity. METHODS Wild-type mice were fed a high-fat diet (HF) for 8 weeks followed by a 2-week treatment with nanoformulated copper/zinc superoxide dismutase (NanoSOD). The mice were divided into: 1) chow diet, 2) HF, and 3) HF + NanoSOD. RESULTS The HF + NanoSOD-treated mice showed a significant decrease in plasma and liver triglycerides when compared with HF-fed mice. Interestingly, NanoSOD reduced the expression of macrophage and inflammatory markers in visceral AT (VAT) and stromal cells derived from VAT. Moreover, the activation of proinflammatory signaling pathways, in particular, the extracellular signal-regulated kinases, was blunted in VAT on NanoSOD treatment. However, markers of oxidative stress were not altered significantly in the HF + NanoSOD group in the experimental conditions. Pretreatment of either macrophages or adipocytes significantly reduced the inflammatory response invoked in an in vitro coculture system, further supporting the role of NanoSOD in inhibiting obesity-linked inflammation. CONCLUSIONS This data suggest that NanoSOD is effective not only in reducing AT macrophage accumulation and AT inflammation but also in promoting triglyceride metabolism in obesity.
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Affiliation(s)
- Curtis Perriotte-Olson
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Nikhil Adi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Devika S Manickam
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Rachel A Westwood
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Cyrus V Desouza
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Gopalakrishnan Natarajan
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Alexandra Crook
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
| | - Alexander V Kabanov
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Viswanathan Saraswathi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Research Service, Veterans Administration Nebraska-Western Iowa Health Care System, Omaha, Nebraska, USA
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Saraswathi V, Ganesan M, Perriotte-Olson C, Manickam DS, Westwood RA, Zimmerman MC, Ahmad IM, Desouza CV, Kabanov AV. Nanoformulated copper/zinc superoxide dismutase attenuates vascular cell activation and aortic inflammation in obesity. Biochem Biophys Res Commun 2015; 469:495-500. [PMID: 26692492 DOI: 10.1016/j.bbrc.2015.12.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/08/2015] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Endothelial cell (EC) oxidative stress can lead to vascular dysfunction which is an underlying event in the development of cardiovascular disease (CVD). The lack of a potent and bioavailable anti-oxidant enzyme is a major challenge in studies on antioxidant therapy. The objective of this study is to determine whether copper/zinc superoxide dismutase (CuZnSOD or SOD1) after nanoformulation (nanoSOD) can effectively reduce EC oxidative stress and/or vascular inflammation in obesity. METHODS Human aortic endothelial cells (HAECs) were treated with native- or nanoSOD for 6 h followed by treatment with linoleic acid (LA), a free fatty acid, for 6-24 h. To determine the in vivo relevance, the effectiveness of nanoSOD in reducing vascular cell activation was studied in a mouse model of diet-induced obesity. RESULTS We noted that nanoSOD was more effectively taken up by ECs than native SOD. Western blot analysis further confirmed that the intracellular accumulation of SOD1 protein was greatly increased upon nanoSOD treatment. Importantly, nanoSOD pretreatment led to a significant decrease in LA-induced oxidative stress in ECs which was associated with a marked increase in SOD enzyme activity in ECs. In vivo studies showed a significant decrease in markers of EC/vascular cell activation and/or inflammation in visceral adipose tissue (VAT), thoracic aorta, and heart collected from nanoSOD-treated mice compared to obese control mice. Interestingly, the expression of metallothionein 2, an antioxidant gene was significantly increased in nanoSOD-treated mice. CONCLUSION Our data show that nanoSOD is very effective in delivering active SOD to ECs and in reducing EC oxidative stress. Our data also demonstrate that nanoSOD will be a useful tool to reduce vascular cell activation in VAT and aorta in obesity which, in turn, can protect against obesity-associated CVD, in particular, hypertension.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA; Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA.
| | - Murali Ganesan
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - Curtis Perriotte-Olson
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - Devika S Manickam
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rachel A Westwood
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA; VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA
| | - Matthew C Zimmerman
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Iman M Ahmad
- Radiation Science Technology Education, College of Allied Health Professions, University of Nebraska Medical Center, Omaha, USA
| | - Cyrus V Desouza
- VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center, Omaha, NE, USA
| | - Alexander V Kabanov
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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18
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Adi N, Perriotte-Olson C, Desouza C, Ramalingam R, Saraswathi V. Hematopoietic cyclooxygenase-2 deficiency increases adipose tissue inflammation and adiposity in obesity. Obesity (Silver Spring) 2015; 23:2037-45. [PMID: 26316178 PMCID: PMC6368065 DOI: 10.1002/oby.21184] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 05/18/2015] [Accepted: 05/20/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Adipose tissue (AT) macrophages mediate AT inflammation in obesity, and cyclooxygenase-2 (COX-2) is a major inflammatory gene. It was hypothesized that deletion of hematopoietic COX-2 will inhibit AT inflammation in obesity. METHODS Lethally irradiated wild-type (WT) mice were injected with bone marrow (BM) cells collected from WT or COX-2 knock-out (COX-2-/-) donor mice and fed a high-fat diet for 16 weeks. RESULTS The mice that received BM cells from COX-2-/- mice (BM-COX-2-/-) gained increased body weight, fat mass, and visceral AT (VAT) mass. These mice exhibited reduced inflammatory markers in the VAT stromal vascular cells (SVC). However, the inflammatory markers were increased in adipocyte fraction and/or whole VAT. The activation of ERK1/2 MAPK, a pro-inflammatory signaling pathway, was increased in BM-COX-2-/- mice. The molecular markers of adipogenesis were increased in the VAT or adipocyte fraction. Wnt signaling markers which inhibit adipogenesis, including Wnt3A and DVL3, were reduced, and Wnt5a/b which promotes inflammation was increased in the VAT and/or adipocytes. Finally, an increase in hepatic triglyceride levels in BM-COX-2-/- mice was noted. CONCLUSIONS The data suggest that COX-2 deletion in hematopoietic cells reduces SVC inflammation but increases VAT inflammation and promotes adiposity likely via altered Wnt signaling.
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Affiliation(s)
- Nikhil Adi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center
- VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Curtis Perriotte-Olson
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center
- VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Cyrus Desouza
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center
- VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Ramesh Ramalingam
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center
- VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Viswanathan Saraswathi
- Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism, University of Nebraska Medical Center
- VA Nebraska-Western Iowa Health Care System, Omaha, Nebraska
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee
- Address correspondence to: Viswanathan Saraswathi, Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE. Ph: 402-995-3033; Fax: 402-449-0604;
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Saraswathi V, Meena K, Perriotte‐Olson C, Desouza C, Bowen J, Adi N, Ramalingam R. Ablation of COX‐2 Attenuates Adipose Inflammation but Impairs Metabolic Homeostasis in Diet‐induced Obesity. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.818.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Viswanathan Saraswathi
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Kiran Meena
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Curtis Perriotte‐Olson
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Cyrus Desouza
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Jayden Bowen
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Nikhil Adi
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
| | - Ramesh Ramalingam
- Dept. of Internal Medicine/DEM Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care System, Omaha, NEOmahaNEUnited States
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20
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Saraswathi V, Murali G, Desouza C, Manickam D, Bronich T, Kabanov A. NanoSOD reduces adipose tissue inflammation in obesity (1107.10). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.1107.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Viswanathan Saraswathi
- Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care SystemOmahaNEUnited States
| | - Ganesan Murali
- Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care SystemOmahaNEUnited States
| | - Cyrus Desouza
- Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care SystemOmahaNEUnited States
| | - Devika Manickam
- Division of Molecular Therapeutics University of North CarolinaCHAPEL HILLNCUnited States
| | - Tatiana Bronich
- Univ. of Nebraska Medical Center and VA Nebraska Western Iowa Health Care SystemOmahaNEUnited States
| | - Alexander Kabanov
- Division of Molecular Therapeutics University of North CarolinaCHAPEL HILLNCUnited States
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21
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Murali G, Desouza CV, Clevenger ME, Ramalingam R, Saraswathi V. Differential effects of eicosapentaenoic acid and docosahexaenoic acid in promoting the differentiation of 3T3-L1 preadipocytes. Prostaglandins Leukot Essent Fatty Acids 2014; 90:13-21. [PMID: 24332315 DOI: 10.1016/j.plefa.2013.10.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/01/2013] [Accepted: 10/30/2013] [Indexed: 11/24/2022]
Abstract
The objective of this study was to determine the effects of enrichment with n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the differentiation of 3T3-L1 preadipocytes. Enrichment with DHA but not EPA significantly increased the differentiation markers compared to control differentiated cells. DHA compared to EPA treatment led to a greater increase in adiponectin secretion and, conditioned media collected from DHA treated cells inhibited monocyte migration. Moreover, DHA treatment resulted in inhibition of pro-inflammatory signaling pathways. DHA treated cells predominantly accumulated DHA in phospholipids whereas EPA treatment led to accumulation of both EPA and its elongation product docosapentaenoic acid (DPA), an n-3 fatty acid. Of note, adding DPA to DHA inhibited DHA-induced differentiation. The differential effects of EPA and DHA on preadipocyte differentiation may be due, in part, to differences in their intracellular modification which could impact the type of n-3 fatty acids incorporated into the cells.
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Affiliation(s)
- Ganesan Murali
- Departments of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Omaha, NE, United States; Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States; Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE, United States
| | - Cyrus V Desouza
- Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE, United States; Departments of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Omaha, NE, United States
| | - Michelle E Clevenger
- Departments of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Omaha, NE, United States; Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE, United States
| | - Ramesh Ramalingam
- Departments of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Omaha, NE, United States; Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE, United States
| | - Viswanathan Saraswathi
- Departments of Internal Medicine, Division of Diabetes, Endocrinology, and Metabolism, Omaha, NE, United States; Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, United States; Research Services, VA Nebraska Western Iowa Health Care System, Omaha, NE, United States.
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22
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Saraswathi V, Ramnanan CJ, Wilks AW, Desouza CV, Eller AA, Murali G, Ramalingam R, Milne GL, Coate KC, Edgerton DS. Impact of hematopoietic cyclooxygenase-1 deficiency on obesity-linked adipose tissue inflammation and metabolic disorders in mice. Metabolism 2013; 62:1673-85. [PMID: 23987235 PMCID: PMC4845736 DOI: 10.1016/j.metabol.2013.07.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 06/13/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Adipose tissue (AT)-specific inflammation is considered to mediate the pathological consequences of obesity and macrophages are known to activate inflammatory pathways in obese AT. Because cyclooxygenases play a central role in regulating the inflammatory processes, we sought to determine the role of hematopoietic cyclooxygenase-1 (COX-1) in modulating AT inflammation in obesity. MATERIALS/METHODS Bone marrow transplantation was performed to delete COX-1 in hematopoietic cells. Briefly, female wild type (wt) mice were lethally irradiated and injected with bone marrow (BM) cells collected from wild type (COX-1+/+) or COX-1 knock-out (COX-1-/-) donor mice. The mice were fed a high fat diet for 16 weeks. RESULTS The mice that received COX-1-/- bone marrow (BM-COX-1-/-) exhibited a significant increase in fasting glucose, total cholesterol and triglycerides in the circulation compared to control (BM-COX-1+/+) mice. Markers of AT-inflammation were increased and were associated with increased leptin and decreased adiponectin in plasma. Hepatic inflammation was reduced with a concomitant reduction in TXB2 levels. The hepatic mRNA expression of genes involved in lipogenesis and lipid transport was increased while expression of genes involved in regulating hepatic glucose output was reduced in BM-COX-1-/- mice. Finally, renal inflammation and markers of renal glucose release were increased in BM-COX-1-/- mice. CONCLUSION Hematopoietic COX-1 deletion results in impairments in metabolic homeostasis which may be partly due to increased AT inflammation and dysregulated adipokine profile. An increase in renal glucose release and hepatic lipogenesis/lipid transport may also play a role, at least in part, in mediating hyperglycemia and dyslipidemia, respectively.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics; Department of Internal Medicine/Division of Diabetes, Endocrinology, and Metabolism; Department of Cellular and Integrative Physiology, University of Nebraska Medical Center; VA Nebraska Western Iowa Health Care System, Omaha, NE.
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23
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Winnick JJ, Ramnanan CJ, Saraswathi V, Roop J, Scott M, Jacobson P, Jung P, Basu R, Cherrington AD, Edgerton DS. Effects of 11β-hydroxysteroid dehydrogenase-1 inhibition on hepatic glycogenolysis and gluconeogenesis. Am J Physiol Endocrinol Metab 2013; 304:E747-56. [PMID: 23403942 PMCID: PMC3625750 DOI: 10.1152/ajpendo.00639.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to determine the effect of prolonged 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1) inhibition on basal and hormone-stimulated glucose metabolism in fasted conscious dogs. For 7 days prior to study, either an 11β-HSD1 inhibitor (HSD1-I; n = 6) or placebo (PBO; n = 6) was administered. After the basal period, a 4-h metabolic challenge followed, where glucagon (3×-basal), epinephrine (5×-basal), and insulin (2×-basal) concentrations were increased. Hepatic glucose fluxes did not differ between groups during the basal period. In response to the metabolic challenge, hepatic glucose production was stimulated in PBO, resulting in hyperglycemia such that exogenous glucose was required in HSD-I (P < 0.05) to match the glycemia between groups. Net hepatic glucose output and endogenous glucose production were decreased by 11β-HSD1 inhibition (P < 0.05) due to a reduction in net hepatic glycogenolysis (P < 0.05), with no effect on gluconeogenic flux compared with PBO. In addition, glucose utilization (P < 0.05) and the suppression of lipolysis were increased (P < 0.05) in HSD-I compared with PBO. These data suggest that inhibition of 11β-HSD1 may be of therapeutic value in the treatment of diseases characterized by insulin resistance and excessive hepatic glucose production.
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Affiliation(s)
- J. J. Winnick
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - C. J. Ramnanan
- 2Department of Cellular and Molecular Medicine, University of Ottawa School of Medicine, Ottawa, Ontario, Canada;
| | - V. Saraswathi
- 3Department of Medicine, University of Nebraska Medical Center, Omaha, Nebraska;
| | - J. Roop
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - M. Scott
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - P. Jacobson
- 4Abbott Laboratories, Chicago, Illinois; and
| | - P. Jung
- 4Abbott Laboratories, Chicago, Illinois; and
| | - R. Basu
- 5Department of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - A. D. Cherrington
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - D. S. Edgerton
- 1Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee;
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24
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Raju R, Suneetha S, Sagili K, Meher VC, Saraswathi V, Satyanarayana AVV, Suneetha LM. Diagnostic role of the antibody response to the 38kDa, 16kDa proteins and lipoarabinomannan of mycobacterium tuberculosis. Indian J Clin Biochem 2012; 20:123-8. [PMID: 23105508 DOI: 10.1007/bf02893056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The antibody response to the 38kDa, 16kDa and Lipoarabinomannan (LAM) antigens ofMycobacterium tuberculosis was evaluated using three different ELISAs based on these antigens. The study group included tuberculosis patients (n=52), patients with HIV and TB co-infection (n=10), other chest symptomatics (n=5), HIV infected individuals (n=10), leprosy cases (n=7) and healthy controls (n=75). The results indicate that the 38kDa and LAM based ELISA for IgM/IgG has a low specificity (ranging from 69-85%) and sensitivity (ranging from 55-78%). When three ELISAs are carried out on a single patient the probability of detection of tuberculosis was significantly increased to 95.2% indicating that a single ELISA test is of low sensitivity and that a combination of ELISA's may be needed to be of any value as a diagnostic test for tuberculosis. Additionally, a western blot assay of the serum antibody response to protein fraction ofM. tuberculosis was analysed in 15 tuberculosis patients and five healthy controls. A multiple antibody response to various M.tuberculosis proteins was observed which varied from patient to patient as compared to controls who showed a single 38-39 kDa protein band positivity. These finding suggest that a western blot assay which determines the antibody response to a set of antigenic components ofM. tuberculosis could be a better serological test for the diagnosis of tuberculosis in our population.
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Affiliation(s)
- Renuka Raju
- Blue Peter Research Centre, LEPRA India, Hyderabad, India
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25
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Murali G, Milne GL, Webb CD, Stewart AB, McMillan RP, Lyle BC, Hulver MW, Saraswathi V. Fish oil and indomethacin in combination potently reduce dyslipidemia and hepatic steatosis in LDLR(-/-) mice. J Lipid Res 2012; 53:2186-2197. [PMID: 22847176 DOI: 10.1194/jlr.m029843] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Fish oil (FO) is a potent anti-inflammatory and lipid-lowering agent. Because inflammation can modulate lipid metabolism and vice versa, we hypothesized that combining FO with cyclooxygenase inhibitors (COXIBs), well-known anti-inflammatory drugs, can enhance the anti-inflammatory and lipid-lowering effect of FO. LDLR(-/-) mice were fed a high-fat diet supplemented with 6% olive oil or FO for 12 wk in the presence or absence of indomethacin (Indo, 6 mg/l drinking water). FO reduced plasma total cholesterol by 30% but, in combination with Indo, exerted a greater decrease (44%). The reduction of liver cholesterol ester (CE) and triglycerides (TG) by FO (63% and 41%, respectively) was enhanced by Indo (80% in CE and 64% in TG). FO + Indo greatly increased the expression of genes modulating lipid metabolism and reduced the expression of inflammatory genes compared with control. The mRNA and/or protein expression of pregnane X receptor (PXR) and cytochrome P450 isoforms that alter inflammation and/or lipid metabolism are increased to a greater extent in mice that received FO + Indo. Moroever, the nuclear level of PXR is significantly increased in FO + Indo group. Combining FO with COXIBs may exert their beneficial effects on inflammation and lipid metabolism via PXR and cytochrome P450.
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Affiliation(s)
- Ganesan Murali
- Division of Diabetes, Endocrinology and Metabolism, University of Nebraska Medical Center and the VA Nebraska Western Iowa Health Care System, Omaha, NE
| | - Ginger L Milne
- Department of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Corey D Webb
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN; and
| | - Ann B Stewart
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN; and
| | - Ryan P McMillan
- Department of Human Nutrition, Foods, and Exercise and The Virginia Tech Metabolic Phenotyping Core, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Brandon C Lyle
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN; and
| | - Matthew W Hulver
- Department of Human Nutrition, Foods, and Exercise and The Virginia Tech Metabolic Phenotyping Core, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN; and.
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26
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Ganesan M, Clevenger M, Desouza C, Saraswathi V. Abstract 142: Effects of Omega-3 Fatty Acids on 3T3-L1 Preadipocyte Differentiation and Inflammatory Response. Arterioscler Thromb Vasc Biol 2012. [DOI: 10.1161/atvb.32.suppl_1.a142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Adipose tissue (AT)-specific inflammation in obesity is associated with several metabolic disorders such as insulin resistance, and hepatic steatosis. We and others have shown that fish oil containing the omega-3 fatty acids increases AT mass in animal models which is associated with reduced AT-inflammation, hepatic steatosis, and dyslipidemia. Therefore, the objective of this study is to determine whether the omega-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) induce the differentiation process in 3T3-L1 preadipocytes.
Methods:
3T3-L1 cells were pretreated and differentiated in the presence of different long chain fatty acids such as oleic acid (OA), stearic acid (SA), EPA, DHA, or a mixture of EPA and DHA (E+D) at a concentration of 50 μM.
Results:
Oil red O staining revealed that the differentiation process was remarkably increased in cells treated with DHA and, to a lesser extent with SA, compared to control cells differentiated in the absence of fatty acids. Real time PCR analysis showed that the expression of aP2, a marker of preadipocyte differentiation, was increased significantly in cells treated with DHA (4.1-fold,
P
<0.001) or SA (2.8-fold, p<0.05), compared to undifferentiated control cells. DHA and E+D but not SA increased the expression of cEBP alpha, another marker of differentiation (8.0-fold and 6.2-fold in DHA and E+D, respectively,
P
<0.001). EPA and OA did not increase the expression of these differentiation markers. SA but not DHA-mediated increase in preadipocyte differentiation was associated with an increase in the expression of MCP-1, an inflammatory marker (1.9-fold,
P
<0.05). Analysis of MAPK pathways that modulate cell differentiation and inflammation showed that treatment with DHA but not other fatty acids, led to a significant decrease in the phosphorylation of ERK1/2 and p38 MAPK compared to differentiated control cells.
Conclusions:
Our data demonstrate that EPA and DHA have differential effects with regard to the differentiation of preadipocytes. Our data also show that unlike SA, the differentiation induced by DHA is not associated with an activation of inflammatory pathways suggesting that this effect of DHA is beneficial in improving the lipid storage function of AT.
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Affiliation(s)
- Murali Ganesan
- Dept. of Internal Medicine/DEM, Univ of Nebraska Med Cntr, Omaha, NE
| | | | - Cyrus Desouza
- Dept. of Internal Medicine/DEM, Univ of Nebraska Med Cntr, Omaha, NE
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Ramnanan CJ, Saraswathi V, Smith MS, Donahue EP, Farmer B, Farmer TD, Neal D, Williams PE, Lautz M, Mari A, Cherrington AD, Edgerton DS. Brain insulin action augments hepatic glycogen synthesis without suppressing glucose production or gluconeogenesis in dogs. J Clin Invest 2011; 121:3713-23. [PMID: 21865644 DOI: 10.1172/jci45472] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 06/22/2011] [Indexed: 01/26/2023] Open
Abstract
In rodents, acute brain insulin action reduces blood glucose levels by suppressing the expression of enzymes in the hepatic gluconeogenic pathway, thereby reducing gluconeogenesis and endogenous glucose production (EGP). Whether a similar mechanism is functional in large animals, including humans, is unknown. Here, we demonstrated that in canines, physiologic brain hyperinsulinemia brought about by infusion of insulin into the head arteries (during a pancreatic clamp to maintain basal hepatic insulin and glucagon levels) activated hypothalamic Akt, altered STAT3 signaling in the liver, and suppressed hepatic gluconeogenic gene expression without altering EGP or gluconeogenesis. Rather, brain hyperinsulinemia slowly caused a modest reduction in net hepatic glucose output (NHGO) that was attributable to increased net hepatic glucose uptake and glycogen synthesis. This was associated with decreased levels of glycogen synthase kinase 3β (GSK3β) protein and mRNA and with decreased glycogen synthase phosphorylation, changes that were blocked by hypothalamic PI3K inhibition. Therefore, we conclude that the canine brain senses physiologic elevations in plasma insulin, and that this in turn regulates genetic events in the liver. In the context of basal insulin and glucagon levels at the liver, this input augments hepatic glucose uptake and glycogen synthesis, reducing NHGO without altering EGP.
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Affiliation(s)
- Christopher J Ramnanan
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA.
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Puglisi MJ, Hasty AH, Saraswathi V. The role of adipose tissue in mediating the beneficial effects of dietary fish oil. J Nutr Biochem 2010; 22:101-8. [PMID: 21145721 DOI: 10.1016/j.jnutbio.2010.07.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 04/14/2010] [Accepted: 07/28/2010] [Indexed: 12/22/2022]
Abstract
Fish oil improves several features of metabolic syndrome (MetS), such as dyslipidemia, insulin resistance and hepatic steatosis. Fish oil may mediate some of its beneficial effects by modulating the storage and/or secretory functions of adipose tissue (AT). The storage of triglycerides in AT is regulated by the availability of free fatty acids and the degree of lipolysis in AT. Fish oil has been shown to reduce lipolysis in several studies, indicating improved triglyceride storage. Importantly, AT secretes a variety of adipokines and fish oil feeding is associated with remarkable changes in the plasma levels of two key adipokines, adiponectin and leptin. Much attention has been focused on the contribution of adiponectin in fish oil-mediated improvements in MetS. However, emerging evidence also indicates a role of leptin in modulating the components of the MetS upon fish oil feeding. In addition to improving the storage and secretory functions of AT, fish oil, and the n-3 fatty acids found in fish oil, has been shown to reduce inflammation in AT. These effects may be in part a result of activation of peroxisome proliferator-activated receptor γ or inhibition of Toll-like receptor 4. Thus, there is compelling evidence that fish oil mediates its beneficial effects on MetS by improving AT storage and secretory functions and by reducing inflammation.
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Affiliation(s)
- Michael J Puglisi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232-0615, USA
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Saraswathi V, Morrow JD, Hasty AH. Dietary fish oil exerts hypolipidemic effects in lean and insulin sensitizing effects in obese LDLR-/- mice. J Nutr 2009; 139:2380-6. [PMID: 19864403 PMCID: PMC2777481 DOI: 10.3945/jn.109.111567] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Obesity is often associated with dyslipidemia, insulin resistance, and hypertension. Together, these metabolic perturbations greatly increase the risk of developing cardiovascular disease and diabetes. Although fish oil is a well-established hypolipidemic agent, the mechanisms by which it mediates its lipid-lowering effects are not clear. In addition, it has not been established whether dietary fish oil has different effects in lean and obese mice. LDL receptor deficient (LDLR-/-) and leptin deficient mice on a LDLR-/- background (ob/ob;LDLR-/-) were fed a high fat diet (39% total fat) supplemented with 6% olive oil or fish oil for 6 wk. Fish oil supplementation resulted in lower concentrations of plasma total cholesterol (P < 0.01), triglycerides (P < 0.01), and free fatty acids (P < 0.001) in lean LDLR-/- mice, but not in ob/ob;LDLR-/- mice. In contrast, a fish oil diet did not modulate insulin sensitivity in lean LDLR-/- mice, but it improved insulin sensitivity in ob/ob;LDLR-/- mice (P < 0.05) compared with olive oil fed ob/ob;LDLR-/- mice. Interestingly, plasma adiponectin concentrations were significantly higher and hepatic steatosis was reduced in both mouse models upon fish oil feeding. Finally, fish oil fed LDLR-/- mice exhibited higher hepatic AMP activated protein kinase (AMPK) phosphorylation (P < 0.05), whereas AMPK phosphorylation was not elevated by fish oil feeding in ob/ob;LDLR-/- mice. Taken together, our data suggest that fish oil reduces hepatic steatosis in both lean and obese mice, has potent plasma lipid lowering effects in lean mice, and exerts insulin sensitizing effects in obese mice.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Jason D. Morrow
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Alyssa H. Hasty
- Department of Molecular Physiology and Biophysics and Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232,To whom correspondence should be addressed.
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Abstract
OBJECTIVE Obesity is often associated with hypertriglyceridemia and elevated free fatty acids (FFAs), which are independent risk factors for cardiovascular disease and diabetes. Although impairment of cholesterol homeostasis is known to induce toxicity in macrophages, the consequence of altered fatty acid homeostasis is not clear. METHODS AND RESULTS Long-chain acyl CoA synthetases (ACSLs) play a critical role in fatty acid homeostasis by channeling fatty acids to diverse metabolic pools. We treated mouse peritoneal macrophages (MPMs) with VLDL or FFAs in the presence of triacsin C, an inhibitor of the 3 ACSL isoforms present in macrophages. Treatment of macrophages with VLDL and triacsin C resulted in reduced TG accumulation but increased intracellular FFA levels, which induced lipotoxicity characterized by apoptosis. Treatment of MPMs with the saturated fatty acid stearic acid in the presence of triacsin C increased intracellular stearic acid and induced apoptosis. Stromal vascular cells collected from high-fat diet-fed mice displayed foam cell morphology and exhibited increased mRNA levels of macrophage markers and ACSL1. Importantly, all of these changes were associated with increased FFA level in AT. CONCLUSIONS Inhibition of ACSLs during fatty acid loading results in apoptosis via accumulation of FFAs. Our data have implications in understanding the consequences of dysregulated fatty acid metabolism in macrophages.
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Affiliation(s)
| | - Alyssa H. Hasty
- Correspondence to: Alyssa H. Hasty, Vanderbilt University Medical Center, 702 Light Hall, Nashville, TN 37232-0615, Phone: 615-322-5177, Fax: 615-322-8973,
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Li S, Sun Y, Liang CP, Thorp EB, Han S, Jehle AW, Saraswathi V, Pridgen B, Kanter JE, Li R, Welch CL, Hasty AH, Bornfeldt KE, Breslow JL, Tabas I, Tall AR. Defective phagocytosis of apoptotic cells by macrophages in atherosclerotic lesions of ob/ob mice and reversal by a fish oil diet. Circ Res 2009; 105:1072-82. [PMID: 19834009 DOI: 10.1161/circresaha.109.199570] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RATIONALE The complications of atherosclerosis are a major cause of death and disability in type 2 diabetes. Defective clearance of apoptotic cells by macrophages (efferocytosis) is thought to lead to increased necrotic core formation and inflammation in atherosclerotic lesions. OBJECTIVE To determine whether there is defective efferocytosis in a mouse model of obesity and atherosclerosis. METHODS AND RESULTS We quantified efferocytosis in peritoneal macrophages and in atherosclerotic lesions of obese ob/ob or ob/ob;Ldlr(-/-) mice and littermate controls. Peritoneal macrophages from ob/ob and ob/ob;Ldlr(-/-) mice showed impaired efferocytosis, reflecting defective phosphatidylinositol 3-kinase activation during uptake of apoptotic cells. Membrane lipid composition of ob/ob and ob/ob;Ldlr(-/-) macrophages showed an increased content of saturated fatty acids (FAs) and decreased omega-3 FAs (eicosapentaenoic acid and docosahexaenoic acid) compared to controls. A similar defect in efferocytosis was induced by treating control macrophages with saturated free FA/BSA complexes, whereas the defect in ob/ob macrophages was reversed by treatment with eicosapentaenoic acid/BSA or by feeding ob/ob mice a fish oil diet rich in omega-3 FAs. There was also defective macrophage efferocytosis in atherosclerotic lesions of ob/ob;Ldlr(-/-) mice and this was reversed by a fish oil-rich diet. CONCLUSIONS The findings suggest that in obesity and type 2 diabetes elevated levels of saturated FAs and/or decreased levels of omega-3 FAs contribute to decreased macrophage efferocytosis. Beneficial effects of fish oil diets in atherosclerotic cardiovascular disease may involve improvements in macrophage function related to reversal of defective efferocytosis and could be particularly important in type 2 diabetes and obesity.
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Affiliation(s)
- Suzhao Li
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY 10032, USA.
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Batoy SMAB, Borgmann S, Flick K, Griffith J, Jones JJ, Saraswathi V, Hasty AH, Kaiser P, Wilkins CL. Lipid and phospholipid profiling of biological samples using MALDI Fourier transform mass spectrometry. Lipids 2008; 44:367-71. [PMID: 19005715 DOI: 10.1007/s11745-008-3260-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 10/17/2008] [Indexed: 11/30/2022]
Abstract
Here we describe a study of the feasibility of lipid and phospholipid (PL) profiling using matrix assisted laser desorption/ionization (MALDI) Fourier transform mass spectrometry (FTMS) for two different applications. In this work PL profiles of different mammalian tissues as well as those of whole cell organisms were examined. In particular, comparative analysis of lipid and PL profiles of tissues from mice fed different diets was done and, in another application, MALDI FTMS was used to analyze PL profiles of genetically modified Saccharomyces cerevisiae. Computational sorting of the observed ions was done in order to group the lipid and PL ions from complex MALDI spectra. The PL profiles of liver tissues from mice fed different diets showed a cross correlation coefficient of 0.2580, indicating significant dissimilarity, and revealed more than 30 significantly different peaks at the 99.9% confidence level. Histogram plots derived from the spectra of wild type and genetically modified yeast resulted in a cross correlation coefficient 0.8941 showing greater similarity, but still revealing a number of significantly different peaks. Based on these results, it appears possible to use MALDI FTMS to identify PLs as potential biomarkers for metabolic processes in whole cells and tissues.
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Affiliation(s)
- S Mariccor A B Batoy
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, USA
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Saraswathi V, Gao L, Morrow JD, Chait A, Niswender KD, Hasty AH. Fish oil increases cholesterol storage in white adipose tissue with concomitant decreases in inflammation, hepatic steatosis, and atherosclerosis in mice. J Nutr 2007; 137:1776-82. [PMID: 17585030 DOI: 10.1093/jn/137.7.1776] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although fish oil has hypolipidemic and antiatherosclerotic properties, the potential for white adipose tissue (WAT) to mediate these effects has not been studied. LDL-receptor deficient (LDLR-/-) mice were fed high fat, olive oil-containing diets supplemented with additional olive oil or with fish oil for 12 wk. Fish oil feeding significantly reduced plasma lipid levels. In contrast, lipid storage in WAT was increased in fish oil-fed mice as evidenced by increased total fat (P < 0.05) and perigonadal WAT mass (P < 0.05), increased cholesterol storage (P < 0.001), and adipocyte hypertrophy. Despite increased adipose tissue mass, WAT-specific inflammation and insulin sensitivity were improved (P < 0.05), concomitant with reduced macrophage infiltration. Furthermore, fish oil increased WAT and plasma levels of adiponectin. In addition, fish oil feeding decreased the formation of proinflammatory F2- isoprostanes, markers of oxidative stress (P < 0.05). The increased WAT lipid storage in fish oil-fed mice was associated with reduced lipid accumulation in liver (P < 0.05) and decreased atherosclerotic lesion area (P < 0.05). Taken together, these data highlight the specific role of WAT in regulating dietary fish oil-mediated improvement in systemic lipid homeostasis and atherosclerosis.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Gruen ML, Saraswathi V, Nuotio-Antar AM, Plummer MR, Coenen KR, Hasty AH. Plasma insulin levels predict atherosclerotic lesion burden in obese hyperlipidemic mice. Atherosclerosis 2006; 186:54-64. [PMID: 16102772 DOI: 10.1016/j.atherosclerosis.2005.07.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 06/21/2005] [Accepted: 07/06/2005] [Indexed: 10/25/2022]
Abstract
Despite a clear association between obesity, insulin resistance and atherosclerosis in humans, to date, no animal models have been described in which insulin resistance is associated with atherosclerotic lesion burden. Using two mouse models of obesity-induced hyperlipidemia:leptin deficient (ob/ob) mice on an apolipoprotein E deficient (apoE-/-) or low density lipoprotein receptor deficient (LDLR-/-) background, we sought to determine metabolic parameters most closely associated with atherosclerotic lesion burden. Total plasma cholesterol (TC) levels in ob/ob;apoE-/- mice and ob/ob;LDLR-/- mice were indistinguishable (682+/-48 versus 663+/-16, respectively). Analysis of lipoprotein profiles showed that cholesterol was carried primarily on VLDL in the ob/ob;apoE-/- mice and on LDL in the ob/ob;LDLR-/- mice. Plasma triglycerides (TG) were 55% lower (P<0.001), non-esterified fatty acids (NEFA) were 1.5-fold higher (P<0.01), and insulin levels were 1.7-fold higher (NS) in ob/ob;apoE-/- mice compared to ob/ob;LDLR-/- mice. Other parameters such as body weight, fat pad weight, and glucose levels were not different between the groups. Aortic sinus lesion area of ob/ob;apoE-/- mice was increased 3.2-fold above ob/ob;LDLR-/- mice (102,455+/-8565 microm2/section versus 31,750+/-4478 microm2/section, P<0.001). Lesions in ob/ob;apoE-/- mice were also more complex as evidenced by a 7.7-fold increase in collagen content (P<0.001). Atherosclerotic lesion area was positively correlated with body weight (P<0.005), NEFA (P=0.007), and insulin (P=0.002) levels in the ob/ob;LDLR-/- mice and with insulin (P=0.014) in the ob/ob;apoE-/- mice. In contrast, lesion burden was neither associated with TC and TG, nor with individual lipoprotein pools, in either animal model. These data provide a direct demonstration of the pathophysiologic relevance of hyperinsulinemia, NEFA, and increased body weight to atherosclerotic lesion formation.
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Affiliation(s)
- Marnie L Gruen
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Room 702 Light Hall, Nashville, TN 37232-0615, USA
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Saraswathi V, Hasty AH. The role of lipolysis in mediating the proinflammatory effects of very low density lipoproteins in mouse peritoneal macrophages. J Lipid Res 2006; 47:1406-15. [PMID: 16639077 DOI: 10.1194/jlr.m600159-jlr200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypertriglyceridemia is an important risk factor for atherosclerosis, especially in obesity. Macrophages are one of the primary cell types involved in atherogenesis and are thought to contribute to lesion formation through both lipid accumulation and proinflammatory gene expression. In this study, we sought to determine the direct impact of triglyceride (TG)-rich VLDL-induced lipid accumulation on macrophage proinflammatory processes. Incubation of mouse peritoneal macrophages with 100 microg/ml VLDL for 6 h led to 2.8- and 3.7-fold increases in intracellular TGs and FFAs, respectively (P < 0.05). The inflammatory proteins tumor necrosis factor-alpha, interleukin-1beta, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, matrix metalloproteinase 3 (MMP3), and macrophage inflammatory protein-1alpha (MIP-1alpha) were all upregulated by at least 2-fold (P < 0.05) in a dose-dependent manner in VLDL-treated macrophages. The increase in inflammatory gene expression coincided with the phosphorylation of the mitogen-activated protein kinase (MAPK) pathway members extracellular signal-regulated kinase (ERK) 1/2, stress-activated protein kinase/c-Jun NH2-terminal kinase, and p38 MAPK and was ameliorated by U0126, an inhibitor of ERK1/2. Inhibition of extracellular TG hydrolysis with tetrahydrolipstatin (Orlistat) resulted in the absence of intracellular TG and FFA accumulation and was accompanied by the amelioration of ERK1/2 phosphorylation and MIP-1alpha gene expression. These data indicate that VLDL hydrolysis, and the subsequent accumulation of intracellular FFAs and TGs, plays a substantive role in mediating the proinflammatory effects of VLDL. These data have important implications for the direct proatherogenic effects of VLDL on macrophage-driven atherosclerosis.
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Affiliation(s)
- Viswanathan Saraswathi
- Department of Molecular Physiology and Biophysics,Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Hennig B, Lei W, Arzuaga X, Ghosh DD, Saraswathi V, Toborek M. Linoleic acid induces proinflammatory events in vascular endothelial cells via activation of PI3K/Akt and ERK1/2 signaling. J Nutr Biochem 2006; 17:766-72. [PMID: 16563718 DOI: 10.1016/j.jnutbio.2006.01.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 01/04/2006] [Accepted: 01/09/2006] [Indexed: 11/20/2022]
Abstract
Linoleic acid (18:2n-6), is a major unsaturated fatty acid in the American diet. Linoleic acid is considered to be atherogenic because of its pro-oxidative and proinflammatory properties. There is substantial evidence that linoleic acid (LA) can activate vascular endothelial cells and contribute to an inflammatory response. To explore the mechanisms of LA-induced proinflammatory signaling pathways, the present study addresses the role of the phosphatidylinositol 3-kinase/amino kinase terminal (PI3K/Akt), extracellular signal regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) pathways during vascular endothelial cell activation. After a 3- to 6-h exposure, LA significantly activated both Akt and ERK in endothelial cells, as assessed by western blot and immunofluorescence. In contrast, LA activated p38 MAPK already at 10 min, suggesting that p38 MAPK signaling occurred upstream of the ERK1/2 pathway. Furthermore, inhibition of ERK activity by PD98059 and PI3K/Akt activity by LY294002 or wortmannin significantly reduced the LA-induced activation of nuclear factor kappa B (NF-kappaB). These results suggest a contribution of both the ERK1/2 and PI3K/Akt pathways to the effect of LA on NF-kappaB-dependent transcription. Indeed, LA-mediated gene expression of the vascular cell adhesion molecule 1 was suppressed by PD98059, wortmannin and LY294002. These data indicate that both PI3K/Akt- and ERK1/2-mediated proinflammatory signaling events are critical in LA-induced endothelial cell activation and vascular inflammation.
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Affiliation(s)
- Bernhard Hennig
- Molecular and Cell Nutrition Laboratory, College of Agriculture, University of Kentucky, Lexington, KY 40536-0200, USA.
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Abstract
Hypertriglyceridemia, an important risk factor of atherosclerosis, is associated with increased circulating free fatty acids. Research to date indicates that linoleic acid (LA), the major fatty acid in the American diet, may be atherogenic by activating vascular endothelial cells. However, the exact signaling mechanisms involved in LA-mediated proinflammatory events in endothelial cells still remain unclear. We previously reported increased superoxide formation after LA exposure in endothelial cells. The objective of the present investigation is to determine the role of calcium and peroxynitrite in mediating the proinflammatory effect of LA in vascular endothelial cells. LA exposure increased intracellular calcium, nitric oxide, and tetrahydrodiopterin levels as well as the expression of E-selectin. Inhibiting calcium signaling using 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid and heparin decreased the expression of E-selectin. Also, LA-mediated nuclear factor kappa B activation and E-selectin gene expression were suppressed by Mn (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (a superoxide scavenger), N(G)-monomethyl-l-arginine (an endothelial nitric oxide synthase inhibitor), and 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron (III) chloride (a peroxynitrite scavenger). LA exposure resulted in increased nitrotyrosine levels, as observed by Western blotting and immunofluorescence. Our data suggest that the proinflammatory effects of LA can be mediated through calcium and peroxynitrite signaling.
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Affiliation(s)
- Viswanathan Saraswathi
- Molecular and Cell Nutrition Laboratory, College of Agriculture, University of Kentucky, Lexington, KY 40546, USA
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Hennig B, Hammock BD, Slim R, Toborek M, Saraswathi V, Robertson LW. PCB-induced oxidative stress in endothelial cells: modulation by nutrients. Int J Hyg Environ Health 2002; 205:95-102. [PMID: 12018021 DOI: 10.1078/1438-4639-00134] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
There is an increasing body of evidence suggesting that exposure to Superfund chemicals may have adverse consequences on many organ systems, as well as carcinogenic and atherogenic effects. This is particularly true for polyhalogenated aromatic hydrocarbons such as the polychlorinated biphenyls (PCBs). The vascular endothelium, which is constantly exposed to blood components including environmental contaminants, is extremely vulnerable to chemical insult as well as necrotic and apoptotic injury. Our recent studies suggest that certain PCBs, especially coplanar PCBs, can compromise normal functions of vascular endothelial cells by activating oxidative stress-sensitive signaling pathways and subsequent proinflammatory events critical in the pathology of atherosclerosis and cardiovascular disease. Our findings suggest that an increase in the level of cellular oxidative stress is a significant event in PCB-mediated endothelial cell dysfunction and that nutrients can modulate PCB-induced oxidative stress and endothelial toxicity. We have demonstrated that the dietary fat linoleic acid, the parent unsaturated fatty acid of the omega-6 family, can increase endothelial dysfunction induced by selected PCBs, probably by contributing to oxidative stress and as the result of the production of toxic metabolites called leukotoxins. The subsequent imbalance in the overall cellular oxidant/antioxidant status can activate oxidative stress- or redoxsensitive transcription factors, which in turn promote gene expression for inflammatory cytokines and adhesion molecules, intensifying the inflammatory response and endothelial cell dysfunction. Our data also suggest that antioxidant nutrients such as vitamin E can protect against endothelial cell damage mediated by PCBs or polyunsaturated dietary fats by interfering with oxidative stress-sensitive and proinflammatory signaling pathways. The concept that nutrition can modify or ameliorate the toxicity of Superfund chemicals is provocative and warrants further study as the implications for human health are significant. The information from such studies could be used to develop dietary recommendations and nutritional interventions for populations at high risk for exposure to PCBs, including communities living near Superfund sites and those exposed via occupation or diet.
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Affiliation(s)
- Bernhard Hennig
- Cell Nutrition Group, Department of Animal Sciences, University of Kentucky, Lexington, KY 40546, USA.
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Slim R, Hammock BD, Toborek M, Robertson LW, Newman JW, Morisseau CH, Watkins BA, Saraswathi V, Hennig B. The role of methyl-linoleic acid epoxide and diol metabolites in the amplified toxicity of linoleic acid and polychlorinated biphenyls to vascular endothelial cells. Toxicol Appl Pharmacol 2001; 171:184-93. [PMID: 11243918 DOI: 10.1006/taap.2001.9131] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Selected dietary lipids may increase the atherogenic effects of environmental chemicals, such as polychlorinated biphenyls (PCBs), by cross-amplifying mechanisms leading to dysfunction of the vascular endothelium. We have shown previously that the omega-6 parent fatty acid, linoleic acid, or 3,3',4,4'-tetrachlorobiphenyl (PCB 77), an aryl hydrocarbon (Ah) receptor agonist, independently can cause disruption of endothelial barrier function. Furthermore, cellular enrichment with linoleic acid can amplify PCB-induced endothelial cell dysfunction. We hypothesize that the amplified toxicity of linoleic acid and PCBs to endothelial cells could be mediated in part by cytotoxic epoxide metabolites of linoleic acid called leukotoxins (LTX) or their diol derivatives (LTXD). Exposure to LTXD resulted in a dose-dependent increase in albumin transfer across endothelial cell monolayers, whereas this disruption of endothelial barrier function was observed only at a high concentration of LTX. Pretreatment with the cytosolic epoxide hydrolase inhibitor 1-cyclohexyl-3-dodecyl urea partially protected against the observed LTX-induced endothelial dysfunction. Endothelial cell activation mediated by LTX and/or LTXD also enhanced nuclear translocation of the transcription factor NF-kappa B and gene expression of the inflammatory cytokine IL-6. Inhibiting cytosolic epoxide hydrolase decreased the LTX-mediated induction of both NF-kappa B and the IL-6 gene, whereas the antioxidant vitamin E did not block LTX-induced endothelial cell activation. Most importantly, inhibition of cytosolic epoxide hydrolase blocked both linoleic acid-induced cytotoxicity, as well as the additive toxicity of linoleic acid plus PCB 77 to endothelial cells. Interestingly, cellular uptake and accumulation of linoleic acid was markedly enhanced in the presence of PCB 77. These data suggest that cytotoxic epoxide metabolites of linoleic acid play a critical role in linoleic acid-induced endothelial cell dysfunction. Furthermore, the severe toxicity of PCBs in the presence of linoleic acid may be due in part to the generation of epoxide and diol metabolites. These findings have implications in understanding interactive mechanisms of how dietary fats can modulate dysfunction of the vascular endothelium mediated by certain environmental contaminants.
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Affiliation(s)
- R Slim
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40506-0054, USA
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Saraswathi V, Mathuram V, Subramanian S, Govindasamy S. Modulation of the impaired drug metabolism in sarcoma-180-bearing mice by echitamine chloride. Cancer Biochem Biophys 1999; 17:79-88. [PMID: 10738904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Echitamine chloride (EC), an indole alkaloid, extracted from the bark of Alstonia scholaris has got highly promising anticancer effect. The effect of this drug on the microsomal drug detoxifying system was studied in sarcoma-180 induced mice. When given sub-cutaneously at a dosage of 5 mg/kg body weight, it was able to alter the impaired drug detoxifying system which was observed in the Sarcoma-180 bearing mice. The levels of microsomal protein, Cyt-P450, Cyt-b5, NADH-Cyt-C-reductase, NADPH-Cyt-C-reductase, and glu-6 phosphatase were determined. The levels of these drug metabolizing enzymes were decreased in S-180 bearing mice. EC treatment corrected to near normal levels of these enzymes and microsomal hemeproteins. In order to understand the mechanism responsible for the decreased protein level and its normalization after treatment with EC, 3H-Phenylalanine incorporation study was carried out. From the results, it is observed that the synthesis of apoproteins is also altered in tumor-bearing animals. All these changes which were observed in tumor-bearing animals were corrected to near normal levels after treatment with EC.
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Affiliation(s)
- V Saraswathi
- Department of Biochemistry, University of Madras, Guindy Campus, Chennai
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Saraswathi V, Ramamoorthy N, Subramaniam S, Mathuram V, Gunasekaran P, Govindasamy S. Inhibition of glycolysis and respiration of sarcoma-180 cells by echitamine chloride. Chemotherapy 1998; 44:198-205. [PMID: 9612610 DOI: 10.1159/000007115] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Malignant tumors are known to exhibit high rates of glycolytic activity leading to high production of lactic acid. Hence, neoplastic cells have elevated activity of enzymes responsible for glycolysis. Echitamine chloride, an indole alkaloid extracted from the bark of Alstonia scholaris, has been reported to have a highly promising anticancer activity against fibrosarcoma in rats. In the present study, the effect of echitamine chloride on energy metabolism of S-180 cells is investigated to have a better understanding on the mode of action of echitamine chloride. The effect of echitamine chloride on the mitochondrial and cellular respiration of S-180 cells was studied. Also, the effects on glucose utilization, pyruvate utilization and lactate formation were studied on whole S-180 cells and S-180 cell-free homogenate. The levels of glycolytic enzymes such as hexokinase and lactate dehydrogenase were estimated in which particular emphasis has been laid on hexokinase which occurs both in cytosolic and particulate forms in neoplastic cells. Hence the differential effect of echitamine chloride on the levels of total, cytosolic and particulate hexokinase has been investigated. In conclusion, echitamine chloride affects both cellular and mitochondrial respiration, leading to reduction of the cellular energy pool and thereby resulting in the loss of viability of S-180 cells.
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Affiliation(s)
- V Saraswathi
- Department of Biochemistry, University of Madras, India
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