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Salagre D, Navarro-Alarcón M, Villalón-Mir M, Alcázar-Navarrete B, Gómez-Moreno G, Tamimi F, Agil A. Chronic melatonin treatment improves obesity by inducing uncoupling of skeletal muscle SERCA-SLN mediated by CaMKII/AMPK/PGC1α pathway and mitochondrial biogenesis in female and male Zücker diabetic fatty rats. Biomed Pharmacother 2024; 172:116314. [PMID: 38387135 DOI: 10.1016/j.biopha.2024.116314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/14/2024] [Accepted: 02/17/2024] [Indexed: 02/24/2024] Open
Abstract
Melatonin acute treatment limits obesity of young Zücker diabetic fatty (ZDF) rats by non-shivering thermogenesis (NST). We recently showed melatonin chronically increases the oxidative status of vastus lateralis (VL) in both obese and lean adult male animals. The identification of VL skeletal muscle-based NST by uncoupling of sarcoendoplasmic reticulum Ca2+-ATPase (SERCA)- sarcolipin (SLN) prompted us to investigate whether melatonin is a SERCA-SLN calcium futile cycle uncoupling and mitochondrial biogenesis enhancer. Obese ZDF rats and lean littermates (ZL) of both sexes were subdivided into two subgroups: control (C) and 12 weeks orally melatonin treated (M) (10 mg/kg/day). Compared to the control groups, melatonin decreased the body weight gain and visceral fat in ZDF rats of both sexes. Melatonin treatment in both sex obese rats restored the VL muscle skin temperature and sensitized the thermogenic effect of acute cold exposure. Moreover, melatonin not only raised SLN protein levels in the VL of obese and lean rats of both sexes; also, the SERCA activity. Melatonin treatment increased the SERCA2 expression in obese and lean rats (both sexes), with no effects on SERCA1 expression. Melatonin increased the expression of thermogenic genes and proteins (PGC1-α, PPARγ, and NRF1). Furthermore, melatonin treatment enhanced the expression ratio of P-CaMKII/CaMKII and P-AMPK/AMPK. In addition, it rose mitochondrial biogenesis. These results provided the initial evidence that chronic oral melatonin treatment triggers the CaMKII/AMPK/PGC1α axis by upregulating SERCA2-SLN-mediated NST in ZDF diabetic rats of both sexes. This may further contribute to the body weight control and metabolic benefits of melatonin.
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Affiliation(s)
- D Salagre
- Department of Pharmacology, BioHealth Institute Granada (IBs Granada), Neuroscience Institute (CIBM), School of Medicine, University of Granada, Granada 18016, Spain
| | - M Navarro-Alarcón
- Department of Nutrition and Bromatology, School of Pharmacy, University of Granada, Granada 18071, Spain
| | - M Villalón-Mir
- Department of Nutrition and Bromatology, School of Pharmacy, University of Granada, Granada 18071, Spain
| | - B Alcázar-Navarrete
- CIBERES, Carlos III Health Institute, Madrid, and Pulmonology Unit, Hospital Universitario Virgen de las Nieves, Granada 18014, Spain
| | - G Gómez-Moreno
- Department of Medically Compromised Patients in Dentistry, School of Dentistry, University of Granada, Granada 18011, Spain
| | - F Tamimi
- College of Dental Medicine, QU Health, Qatar University, Doha, Qatar
| | - A Agil
- Department of Pharmacology, BioHealth Institute Granada (IBs Granada), Neuroscience Institute (CIBM), School of Medicine, University of Granada, Granada 18016, Spain.
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2
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Waataja JJ, Nihalani RK, Honda CN, Billington CJ. Use of a bio-electronic device comprising of targeted dual neuromodulation of the hepatic and celiac vagal branches demonstrated enhanced glycemic control in a type 2 diabetic rat model as well as in an Alloxan treated swine model. Front Neurosci 2022; 16:1005932. [PMID: 36389223 PMCID: PMC9640365 DOI: 10.3389/fnins.2022.1005932] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/22/2022] [Indexed: 12/03/2022] Open
Abstract
Background There is an unmet need for new type 2 diabetes treatments providing improved efficacy, durability and customized to improve patient’s compliance. Bio-electronic neuromodulation of Vagus nerve branches innervating organs that regulate plasma glucose, may be a method for treating type 2 diabetes. The pancreas has been shown to release insulin during Vagus stimulation. The hepatic vagal branch, innervating the liver, has been shown to decrease glucose release and decrease insulin resistance following ligation. However, standalone stimulation of the Vagus nerve has shown mixed results and Vagus nerve ligation has undesirable effects. Little is known; however, of the effect on plasma glucose with combined neuromodulation consisting of stimulation of the celiac branch innervating the pancreas with simultaneous high frequency alternating current (HFAC) blockade of the hepatic branch. This study tested the effects of this approach on increasing glycemic control in rat a model of type 2 diabetes and Alloxan treated swine. Materials and methods Zucker obese (fatty) male rats (ZDF fa/fa) were used as a model of type 2 diabetes as well as glucose intolerant Alloxan treated swine. In ZDF rat experiments glycemic control was accessed with an intravenous glucose tolerance test during HFAC-induced hepatic branch block with concurrent celiac stimulation (HFAC + stimulation). In swine experiments glycemic control was accessed by an oral glucose tolerance test during HFAC + stimulation. Insulin measurements were taken prior to and following swine experiments giving insight into beta cell exhaustion. Histopathology was conducted to determine safety of HFAC + stimulation on Vagal branches. Results Zucker rats demonstrated a significant improvement to an intravenous glucose tolerance test during HFAC + stimulation compared to sham. There was no significant difference from sham compared to hepatic vagotomy or celiac stimulation. In Alloxan treated swine, when subjected to HFAC + stimulation, there was a significant improvement in glycemic control as measured by an improvement on oral glucose tolerance tests and a decrease in fasting plasma glucose. Insulin responses were similar prior to and following HFAC + stimulation experiments. Histopathology demonstrated healthy swine Vagus nerves. Conclusion Electrical blockade of the hepatic Vagus branch with simultaneous stimulation of the celiac Vagus branch may be a novel, adjustable and localized approach for a treatment of type 2 diabetes.
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Affiliation(s)
- Jonathan J. Waataja
- ReShape Lifesciences Inc., San Clemente, CA, United States
- *Correspondence: Jonathan J. Waataja,
| | | | - Chris N. Honda
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
| | - Charles J. Billington
- Division of Endocrinology and Diabetes, Department of Medicine, University of Minnesota, Minneapolis, MN, United States
- Minnesota Veterans’ Administration Medical Center, Minneapolis, MN, United States
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3
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Sparks RP, Arango AS, Jenkins JL, Guida WC, Tajkhorshid E, Sparks CE, Sparks JD, Fratti RA. An Allosteric Binding Site on Sortilin Regulates the Trafficking of VLDL, PCSK9, and LDLR in Hepatocytes. Biochemistry 2020; 59:4321-4335. [PMID: 33153264 DOI: 10.1021/acs.biochem.0c00741] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
ApoB lipoproteins (apo B-Lp) are produced in hepatocytes, and their secretion requires the cargo receptor sortilin. We examined the secretion of apo B-Lp-containing very low-density lipoprotein (VLDL), an LDL progenitor. Sortilin also regulates the trafficking of the subtilase PCSK9, which when secreted binds the LDL receptor (LDLR), resulting in its endocytosis and destruction at the lysosome. We show that the site 2 binding compound (cpd984) has multiple effects in hepatocytes, including (1) enhanced Apo-Lp secretion, (2) increased cellular PCSK9 retention, and (3) augmented levels of LDLR at the plasma membrane. We postulate that cpd984 enhances apo B-Lp secretion in part through binding the lipid phosphatidylinositol 3,4,5-trisphosphate (PIP3), which is present at higher levels on circulating VLDL form fed rats relative to after fasting. We attribute the enhanced VLDL secretion to its increased binding affinity for sortilin site 1 induced by cpd984 binding site 2. This hinders PCSK9 binding and secretion, which would subsequently prevent its binding to LDLR leading to its degradation. This suggests that site 2 is an allosteric regulator of site 1 binding. This effect is not limited to VLDL, as cpd984 augments binding of the neuropeptide neurotensin (NT) to sortilin site 1. Molecular dynamics simulations demonstrate that the C-terminus of NT (Ct-NT) stably binds site 1 through an electrostatic interaction. This was bolstered by the ability of Ct-NT to disrupt lower-affinity interactions between sortilin and the site 1 ligand PIP3. Together, these data show that binding cargo at sortilin site 1 is allosterically regulated through site 2 binding, with important ramifications for cellular lipid homeostasis involving proteins such as PCSK9 and LDLR.
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Affiliation(s)
- Robert P Sparks
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Andres S Arango
- Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jermaine L Jenkins
- Structural Biology & Biophysics Facility, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Wayne C Guida
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Beckman Institute for Advanced Science & Technology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Charles E Sparks
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Janet D Sparks
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States.,Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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Wagman AS, Boyce RS, Brown SP, Fang E, Goff D, Jansen JM, Le VP, Levine BH, Ng SC, Ni ZJ, Nuss JM, Pfister KB, Ramurthy S, Renhowe PA, Ring DB, Shu W, Subramanian S, Zhou XA, Shafer CM, Harrison SD, Johnson KW, Bussiere DE. Synthesis, Binding Mode, and Antihyperglycemic Activity of Potent and Selective (5-Imidazol-2-yl-4-phenylpyrimidin-2-yl)[2-(2-pyridylamino)ethyl]amine Inhibitors of Glycogen Synthase Kinase 3. J Med Chem 2017; 60:8482-8514. [DOI: 10.1021/acs.jmedchem.7b00922] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Allan S. Wagman
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Rustum S. Boyce
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Sean P. Brown
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Eric Fang
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Dane Goff
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Johanna M. Jansen
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Vincent P. Le
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Barry H. Levine
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Simon C. Ng
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Zhi-Jie Ni
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - John M. Nuss
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Keith B. Pfister
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Savithri Ramurthy
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Paul A. Renhowe
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - David B. Ring
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Wei Shu
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Sharadha Subramanian
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Xiaohui A. Zhou
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Cynthia M. Shafer
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Stephen D. Harrison
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Kirk W. Johnson
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Dirksen E. Bussiere
- Global Discovery Chemistry, Novartis Institutes for BioMedical Research, 5300 Chiron Way, Emeryville, California 94608, United States
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5
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Szabó K, Énzsöly A, Dékány B, Szabó A, Hajdú RI, Radovits T, Mátyás C, Oláh A, Laurik LK, Somfai GM, Merkely B, Szél Á, Lukáts Á. Histological Evaluation of Diabetic Neurodegeneration in the Retina of Zucker Diabetic Fatty (ZDF) Rats. Sci Rep 2017; 7:8891. [PMID: 28827737 PMCID: PMC5566374 DOI: 10.1038/s41598-017-09068-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/21/2017] [Indexed: 01/24/2023] Open
Abstract
In diabetes, retinal dysfunctions exist prior to clinically detectable vasculopathy, however the pathology behind these functional deficits is still not fully established. Previously, our group published a detailed study on the retinal histopathology of type 1 diabetic (T1D) rat model, where specific alterations were detected. Although the majority of human diabetic patients have type 2 diabetes (T2D), similar studies on T2D models are practically absent. To fill this gap, we examined Zucker Diabetic Fatty (ZDF) rats - a model for T2D - by immunohistochemistry at the age of 32 weeks. Glial reactivity was observed in all diabetic specimens, accompanied by an increase in the number of microglia cells. Prominent outer segment degeneration was detectable with changes in cone opsin expression pattern, without a decrease in the number of labelled elements. The immunoreactivity of AII amacrine cells was markedly decreased and changes were detectable in the number and staining of some other amacrine cell subtypes, while most other cells examined did not show any major alterations. Overall, the retinal histology of ZDF rats shows a surprising similarity to T1D rats indicating that despite the different evolution of the disease, the neuroretinal cells affected are the same in both subtypes of diabetes.
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Affiliation(s)
- Klaudia Szabó
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Anna Énzsöly
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Bulcsú Dékány
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Arnold Szabó
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Rozina I Hajdú
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Tamás Radovits
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Csaba Mátyás
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Attila Oláh
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Lenke K Laurik
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Gábor M Somfai
- Department of Ophthalmology, Semmelweis University, Budapest, H-1085, Hungary
| | - Béla Merkely
- Heart and Vascular Center, Semmelweis University, Budapest, H-1085, Hungary
| | - Ágoston Szél
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, H-1085, Hungary.
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6
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Porfirio MC, Gomes de Almeida JP, Stornelli M, Giovinazzo S, Purper-Ouakil D, Masi G. Can melatonin prevent or improve metabolic side effects during antipsychotic treatments? Neuropsychiatr Dis Treat 2017; 13:2167-2174. [PMID: 28860773 PMCID: PMC5560235 DOI: 10.2147/ndt.s127564] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In the last two decades, second-generation antipsychotics (SGAs) were more frequently used than typical antipsychotics for treating both psychotic and nonpsychotic psychiatric disorders in both children and adolescents, because of their lower risk of adverse neurological effects, that is, extrapyramidal symptoms. Recent studies have pointed out their effect on weight gain and increased visceral adiposity as they induce metabolic syndrome. Patients receiving SGAs often need to be treated with other substances to counteract metabolic side effects. In this paper, we point out the possible protective effect of add-on melatonin treatment in preventing, mitigating, or even reversing SGAs metabolic effects, improving quality of life and providing safer long-term treatments in pediatric patients. Melatonin is an endogenous indolamine secreted during darkness by the pineal gland; it plays a key role in regulating the circadian rhythm, generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, and has many other biological functions, including chronobiotic, antioxidant and neuroprotective properties, anti-inflammatory and free radical scavenging effects, and diminishing oxidative injury and fat distribution. It has been hypothesized that SGAs cause adverse metabolic effects that may be restored by nightly administration of melatonin because of its influence on autonomic and hormonal outputs. Interestingly, atypical anti-psychotics (AAPs) can cause several sleep disorders, and circadian misalignment can influence hormones involved in the metabolic regulation, such as insulin, leptin, and ghrelin; furthermore, a relationship between obesity and sleep curtailment has been demonstrated, as well as sleep deprivation in rats has been associated with hyperphagia. Metabolic effects of melatonin, both central and peripheral, direct and indirect, target most metabolic disorders reported during and after SGA treatment in children, adolescents, and adults. Further systematic studies on psychiatric patients are needed to explore the effect of add-on melatonin on metabolic side effects of SGAs, independent of energy intake, diet, and exercise.
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Affiliation(s)
| | | | - Maddalena Stornelli
- Unit of Child Neurology and Psychiatry, "Tor Vergata" University of Rome, Italy
| | - Silvia Giovinazzo
- Unit of Child Neurology and Psychiatry, "Tor Vergata" University of Rome, Italy
| | - Diane Purper-Ouakil
- Unit of Child and Adolescent Psychiatry, Saint Eloi Hospital, Montpellier, France
| | - Gabriele Masi
- IRCCS Stella Maris, Scientific Institute of Child Neurology and Psychiatry, Calambrone, Pisa, Italy
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7
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Sparks RP, Jenkins JL, Miner GE, Wang Y, Guida WC, Sparks CE, Fratti RA, Sparks JD. Phosphatidylinositol (3,4,5)-trisphosphate binds to sortilin and competes with neurotensin: Implications for very low density lipoprotein binding. Biochem Biophys Res Commun 2016; 479:551-556. [PMID: 27666481 DOI: 10.1016/j.bbrc.2016.09.108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 09/21/2016] [Indexed: 12/27/2022]
Abstract
Sortilin is a multi-ligand sorting receptor that interacts with B100-containing VLDL and LDL as well as other ligands including neurotensin (NT). The current study investigates the hypothesis that phosphatidylinositol (3,4,5)-trisphosphate (PIP3) generated downstream of insulin action can directly bind to sortilin. NT binds to sortilin at a well characterized site via its carboxy terminus (C-term). Using a crystal structure of human sortilin (hsortilin), PIP3 is predicted to bind at this C-term site. Binding of PIP3 to hsortilin is demonstrated using surface plasmon resonance (SPR) flowing PIP3 nanodiscs over immobilized hsortilin. Studies were performed using SPR where dibutanoyl PIP3 is shown to compete with NT for sortilin binding. Rat VLDL and LDL were evaluated for PIP3 content immunologically using monoclonal antibodies directed against PIP3. Rat plasma VLDL contained three times more immunoreactive PIP3 than LDL per μg of protein. Because VLDL contains additional ligands that bind sortilin, to distinguish specific PIP3 binding, we used PIP3 liposomes. Liposome floatation assays were used to demonstrate PIP3 liposome binding to sortilin. Using SPR and immobilized hsortilin, the C-term NT tetrapeptide (P-Y-I-L) is shown to bind to hsortilin. A compound (cpd984) was identified with strong theoretical binding to the site on sortilin involved in NT N-terminal binding. When cpd984 is co-incubated with the tetrapeptide, the affinity of binding to sortilin is increased. Similarly, the affinity of PIP3 liposome binding increased in the presence of cpd984. Overall, results demonstrate that sortilin is a PIP3 binding protein with binding likely to occur at the C-term NT binding site. The presence of multiple ligands on B100-containing lipoproteins, VLDL and LDL, raises the interesting possibility for increased interaction with sortilin based on the presence of PIP3.
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Affiliation(s)
- Robert P Sparks
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Jermaine L Jenkins
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Gregory E Miner
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Yan Wang
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Wayne C Guida
- Department of Chemistry, University of South Florida, Tampa, FL 33520, USA
| | - Charles E Sparks
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Janet D Sparks
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA.
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8
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Cordero-Herrera I, Martín MÁ, Fernández-Millán E, Álvarez C, Goya L, Ramos S. Cocoa and cocoa flavanol epicatechin improve hepatic lipid metabolism in in vivo and in vitro models. Role of PKCζ. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.06.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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9
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Manukyan L, Ubhayasekera SJKA, Bergquist J, Sargsyan E, Bergsten P. Palmitate-induced impairments of β-cell function are linked with generation of specific ceramide species via acylation of sphingosine. Endocrinology 2015; 156:802-12. [PMID: 25535826 DOI: 10.1210/en.2014-1467] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Prolonged exposure to palmitate impairs β-cell function and mass. One of the proposed mechanisms is alteration in ceramide (Cer) generation. In the present study, exposure to palmitate induced the level of palmitoyl transferase and Cer synthases, enzymes of the Cer de novo and salvage pathways, and doubled total Cer levels, which was associated with decreased insulin secretion and augmented apoptosis in MIN6 cells and human islets. By inhibiting enzymes of the pathways pharmacologically with myriocin (ISP-1) or fumonisin B1 or by small interfering RNA (siRNA), we showed that Cer(14:0), Cer(16:0), Cer(20:1), and Cer(24:0) species, generated by the salvage pathway, are linked to the harmful effect of palmitate on β-cells. Oleate attenuates negative effects of palmitate on β-cells. When oleate was included during culture of MIN6 cells with palmitate, the palmitate-induced up-regulation of the enzymes of the de novo and salvage pathways was prevented resulting in normalized levels of all Cer species except Cer(20:1). Our data suggest that enhanced Cer generation in response to elevated palmitate levels involves both de novo and salvage pathways. However, the negative effects of palmitate on β-cells are attributed to generation of Cer species Cer(14:0), Cer(16:0), and Cer(24:0) via acylation of sphingosine.
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Affiliation(s)
- Levon Manukyan
- Department of Medical Cell Biology (L.M., E.S., P.B.), Uppsala University, SE-75123, Uppsala, Sweden; and Analytical Chemistry (S.J.K.A.U., J.B.), Department of Chemistry-Biomedical Center and Science for Life Laboratory, Uppsala University, SE-75123, Uppsala, Sweden
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Fuentes-Antrás J, Picatoste B, Gómez-Hernández A, Egido J, Tuñón J, Lorenzo Ó. Updating experimental models of diabetic cardiomyopathy. J Diabetes Res 2015; 2015:656795. [PMID: 25973429 PMCID: PMC4417999 DOI: 10.1155/2015/656795] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/26/2015] [Accepted: 03/29/2015] [Indexed: 11/17/2022] Open
Abstract
Diabetic cardiomyopathy entails a serious cardiac dysfunction induced by alterations in structure and contractility of the myocardium. This pathology is initiated by changes in energy substrates and occurs in the absence of atherothrombosis, hypertension, or other cardiomyopathies. Inflammation, hypertrophy, fibrosis, steatosis, and apoptosis in the myocardium have been studied in numerous diabetic experimental models in animals, mostly rodents. Type I and type II diabetes were induced by genetic manipulation, pancreatic toxins, and fat and sweet diets, and animals recapitulate the main features of human diabetes and related cardiomyopathy. In this review we update and discuss the main experimental models of diabetic cardiomyopathy, analysing the associated metabolic, structural, and functional abnormalities, and including current tools for detection of these responses. Also, novel experimental models based on genetic modifications of specific related genes have been discussed. The study of specific pathways or factors responsible for cardiac failures may be useful to design new pharmacological strategies for diabetic patients.
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Affiliation(s)
- J. Fuentes-Antrás
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
| | - B. Picatoste
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
| | - A. Gómez-Hernández
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
- Biochemistry and Molecular Biology Department, School of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain
| | - J. Egido
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
| | - J. Tuñón
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
| | - Ó. Lorenzo
- IIS-Fundación Jiménez Díaz, Autónoma University, 28040 Madrid, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM) Network, 28040 Madrid, Spain
- *Ó. Lorenzo:
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Effect of orally administered L. fermentum NCIMB 5221 on markers of metabolic syndrome: an in vivo analysis using ZDF rats. Appl Microbiol Biotechnol 2014; 98:115-26. [PMID: 24121931 DOI: 10.1007/s00253-013-5252-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/05/2013] [Accepted: 09/07/2013] [Indexed: 02/06/2023]
Abstract
Metabolic syndrome, encompassing type 2 diabetes mellitus and cardiovascular disease, is a growing health concern of industrialized countries. Ferulic acid (FA) is a phenolic acid found in foods normally consumed by humans that has demonstrated antioxidant activity, cholesterol-lowering capabilities, and anti-tumorigenic properties. Select probiotic bacteria, including Lactobacillus fermentum NCIMB 5221, produce FA due to intrinsic ferulic acid esterase activity. The aim of the present research was to investigate a FA-producing probiotic, L. fermentum NCIMB 5221, as a biotherapeutic for metabolic syndrome. The probiotic formulation was administered daily for 8 weeks to Zucker diabetic fatty (ZDF) rats, a model of hyperlipidemia and hyperglycemia. Results show that the probiotic formulation reduced fasting insulin levels and insulin resistance, significantly reduced serum triglycerides (p = 0.016), lowered serum low-density lipoprotein cholesterol levels (p = 0.008), and significantly reduced the atherogenic (p = 0.016) and atherosclerosis (p = 0.012) index as compared to the control animals. In addition, the probiotic formulation significantly increased high-density lipoprotein cholesterol levels (p = 0.041) as compared to the control animals. This research indicates that administration of the FA-producing L. fermentum NCIMB 5221 has the potential to reduce insulin resistance, hyperinsulinemia, hypercholesterolemia, and other markers involved in the pathogenesis of metabolic syndrome. Further studies are required to investigate the human clinical potential of the probiotic formulation in affecting the markers and pathogenesis of metabolic syndrome.
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Navarro-Alarcón M, Ruiz-Ojeda FJ, Blanca-Herrera RM, A-Serrano MM, Acuña-Castroviejo D, Fernández-Vázquez G, Agil A. Melatonin and metabolic regulation: a review. Food Funct 2014; 5:2806-32. [DOI: 10.1039/c4fo00317a] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Wang B, Chandrasekera PC, Pippin JJ. Leptin- and leptin receptor-deficient rodent models: relevance for human type 2 diabetes. Curr Diabetes Rev 2014; 10:131-45. [PMID: 24809394 PMCID: PMC4082168 DOI: 10.2174/1573399810666140508121012] [Citation(s) in RCA: 343] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 05/06/2014] [Accepted: 05/07/2014] [Indexed: 12/11/2022]
Abstract
Among the most widely used animal models in obesity-induced type 2 diabetes mellitus (T2DM) research are the congenital leptin- and leptin receptor-deficient rodent models. These include the leptin-deficient ob/ob mice and the leptin receptor-deficient db/db mice, Zucker fatty rats, Zucker diabetic fatty rats, SHR/N-cp rats, and JCR:LA-cp rats. After decades of mechanistic and therapeutic research schemes with these animal models, many species differences have been uncovered, but researchers continue to overlook these differences, leading to untranslatable research. The purpose of this review is to analyze and comprehensively recapitulate the most common leptin/leptin receptor-based animal models with respect to their relevance and translatability to human T2DM. Our analysis revealed that, although these rodents develop obesity due to hyperphagia caused by abnormal leptin/leptin receptor signaling with the subsequent appearance of T2DM-like manifestations, these are in fact secondary to genetic mutations that do not reflect disease etiology in humans, for whom leptin or leptin receptor deficiency is not an important contributor to T2DM. A detailed comparison of the roles of genetic susceptibility, obesity, hyperglycemia, hyperinsulinemia, insulin resistance, and diabetic complications as well as leptin expression, signaling, and other factors that confound translation are presented here. There are substantial differences between these animal models and human T2DM that limit reliable, reproducible, and translatable insight into human T2DM. Therefore, it is imperative that researchers recognize and acknowledge the limitations of the leptin/leptin receptor- based rodent models and invest in research methods that would be directly and reliably applicable to humans in order to advance T2DM management.
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Affiliation(s)
| | | | - John J Pippin
- Physicians Committee for Responsible Medicine, 5100 Wisconsin Avenue NW, Suite 400, Washington, DC 20016, USA.
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Lezcano EJ, Iñigo P, Larraga AM, Barranquero C, Gimenez I, Osada J. Caloric restriction or telmisartan control dyslipidemia and nephropathy in obese diabetic Zücker rats. Diabetol Metab Syndr 2014; 6:10. [PMID: 24468233 PMCID: PMC3906927 DOI: 10.1186/1758-5996-6-10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/23/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The obese Zücker diabetic fatty male rat (ZDF:Gmi™-fa) is an animal model of type II diabetes associated with obesity and related metabolic disturbances like dyslipidaemia and diabetic nephropathy. In addition, diabetic dyslipidaemia has been linked to vascular and glomerular damage too. Dietary fat restriction is a current strategy to tackle obesity and, telmisartan, as a renoprotective agent, may mediate cholesterol efflux by activating PPARγ. To test the hypothesis that both therapeutical alternatives may influence dyslipidaemia and nephropathy in the ZDF rat, we studied their effect on development of diabetes. METHODS Male Zücker Diabetic Fatty (ZDF) rats received a low-calorie diet, vehicle or telmisartan for 9 weeks. Blood samples were obtained for analyses of lipids and lipoproteins, LDL-oxidisability, HDL structural and functional properties. Urinalysis was carried out to estimate albumin loss. At the end of the experimental period, rats were sacrificed, liver extracted and APOA1 mRNA quantified. RESULTS Results indicated that low-calorie diet and telmisartan can slower the onset of overt hyperglycaemia and renal damage assessed as albuminuria. Both interventions decreased the oxidative susceptibility of LDL and hepatic APOA1 mRNA expression but only dietary restriction lowered hyperlipidaemia. CONCLUSION Either a dietary or pharmacologic interventions with telmisartan have important beneficial effects in terms of LDL oxidative susceptibility and progression of albuminuria in obesity related type II diabetes.
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Affiliation(s)
- Eduardo J Lezcano
- Servicio de Cardiología, Hospital de San Pedro, Logroño, Calle Piqueras, 98 26006 Logroño, La Rioja, Spain
| | - Pablo Iñigo
- Departamento de Medicina. Facultad de Medicina. Servicio de Nefrología, Hospital Clínico Universitario “Lozano Blesa”, Universidad de Zaragoza, Zaragoza, Spain
| | - Ana M Larraga
- Departamento de Medicina. Facultad de Medicina. Servicio de Nefrología, Hospital Clínico Universitario “Lozano Blesa”, Universidad de Zaragoza, Zaragoza, Spain
| | - Cristina Barranquero
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón - Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Ignacio Gimenez
- Departamento de Farmacología y Fisiología, Universidad de Zaragoza, Zaragoza, Spain
| | - Jesús Osada
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Veterinaria, Instituto de Investigación Sanitaria de Aragón - Universidad de Zaragoza, Zaragoza, Spain
- CIBER de Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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Hartvigsen ML, Jeppesen PB, Lærke HN, Njabe EN, Knudsen KEB, Hermansen K. Concentrated arabinoxylan in wheat bread has beneficial effects as rye breads on glucose and changes in gene expressions in insulin-sensitive tissues of Zucker diabetic fatty (ZDF) rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:5054-5063. [PMID: 23656567 DOI: 10.1021/jf3043538] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The health-promoting effects of dietary fiber may vary with content, structure, and composition in the diet. The aim was to study how low-fiber wheat bread (WB), wheat bread supplemented with wheat arabinoxylan (AX) or oat β-glucan (BG), whole meal rye bread (RM), and rye bread with kernels (RK) affected central parameters of glucose and lipid metabolism and gene changes of Zucker diabetic fatty rats. Blood glucose response areas after an oral glucose tolerance test were significantly lower after AX (mean ± SEM; 2117 ± 170 mmol/L·180 min), RM (1978 ± 206 mmol/L·180 min), and RK (2234 ± 262 mmol/L·180 min) breads than after WB (3586 ± 100 mmol/L·180 min; p < 0.0001). AX, RK, and RM changed expressions of adipose GAPDH, AMPK, FAS, SREBP-1c, and hepatic PCG-1α, whereas BG had similar effects as WB. Thus, arabinoxylan added to wheat bread had beneficial effects on glycemic control as whole grain rye bread in this animal model.
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Qin B, Anderson RA, Kuzuya T, Kitaura Y, Shimomura Y. Multiple factors and pathways involved in hepatic very low density lipoprotein-apoB100 overproduction in Otsuka Long-Evans Tokushima Fatty rats. Atherosclerosis 2012; 222:409-16. [PMID: 22546076 DOI: 10.1016/j.atherosclerosis.2012.03.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 03/02/2012] [Accepted: 03/29/2012] [Indexed: 01/04/2023]
Abstract
AIMS Overproduction of hepatic very low-density lipoprotein (VLDL) particles is a major abnormality of lipoprotein dysregulation in type 2 diabetes (T2D). We sought to examine the relationship between systemic/hepatic inflammation associated with insulin resistance and apolipoprotein (apo)B100-containing VLDL production. METHODS AND RESULTS At the age of 19 wks, Otsuka Long-Evans Tokushima Fatty (OLETF) rats showed systemic inflammation (plasma TNF-α and interleukin (IL)-6 levels increased), insulin resistance (plasma retinol binding protein 4 and soluble CD36 levels were higher), dyslipidemia and fatty liver (plasma and liver triglyceride and cholesterol levels were higher as well as total VLDL-, VLDL(1)-, VLDL(2)-apoB100 and VLDL-triglycerides were overproduced), compared with the control rats. In livers of OLETF rats, mRNA levels of tnf, il1b and il6 were increased, but an anti-inflammatory protein, zinc finger protein 36, and its mRNA expression were decreased. We also found that the liver mRNA, protein levels, and tyrosine phosphorylation (pY) of insulin receptor (InsR) substrate (IRS) 2, but not IRS1, were decreased in OLETF rats; pY of InsR and Akt protein and phospho-Akt (ser437) were also reduced; but protein tyrosine phosphatase-1B protein was overexpressed. The gene expressions of glucose transporters 1 and 2, and glycogen synthase were decreased, but phosphatase and tensin homolog deleted on chromosome ten and glycogen synthase kinase 3β mRNAs were overexpressed, compared with the controls. Sterol regulatory element binding protein-1c mRNA, ATP-binding cassette transporter A1 mRNA, microsomal triglyceride transfer protein mRNA/protein, and CD36 mRNA/protein levels were increased and lipoprotein lipase and Niemann-Pick c1-like1 mRNA levels were decreased, which are all involved in lipogenesis. Decreased sirtuins1-3 mRNA levels were also observed in OLETF rats. CONCLUSIONS These abnormal genes, proteins expression and phosphorylation of multiple pathways related to inflammatory, insulin signaling and lipogenesis may be important underlying factors in VLDL-apoB100 particles overproduction observed in T2D. Our data contribute to the further understanding of an association of dyslipoproteinemia with systemic metabolic disorders, fatty liver and dysregulated hepatic metabolic pathways.
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Affiliation(s)
- Bolin Qin
- United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics and Immunology Laboratory, Beltsville, MD 20705, USA.
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Rinaldi B, Di Filippo C, Capuano A, Donniacuo M, Sodano L, Ferraraccio F, Rossi F, D'Amico M. Adiponectin elevation by telmisartan ameliorates ischaemic myocardium in Zucker diabetic fatty rats with metabolic syndrome. Diabetes Obes Metab 2012; 14:320-8. [PMID: 22050607 DOI: 10.1111/j.1463-1326.2011.01527.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM This study investigated whether telmisartan, a selective angiotensin type 1 (AT1) receptor antagonist and gamma peroxisome proliferator-activated receptor (PPAR-γ) partial agonist, reduces myocardial ischaemia/reperfusion (I/R) injury in an experimental model of metabolic syndrome. METHODS Zucker Diabetic Fatty (ZDF) rats were treated for 3 weeks with telmisartan at doses of 2, 7 and 12 mg/kg/day. After treatment, rats were subjected to a 25-min occlusion of the left descending coronary artery followed by 2-h reperfusion (I/R). RESULTS Telmisartan reduced the extension of the infarct size in a dose-dependent fashion and decreased the levels of plasma troponin I, a specific marker of myocardial damage. Telmisartan also caused a dose-dependent increase in adiponectin both in plasma and cardiac tissue of infarcted ZDF rats. These levels were minimally increased (p < 0.05 vs. vehicle) by telmisartan 7 mg/kg/day and reached the maximum values with the highest dose of 12 mg/kg/day (p < 0.01 vs. vehicle). In contrast, within the infarcted tissue telmisartan decreased the expression of markers of inflammation such as the transcription factor NF-κB, the toll-like receptors TLR2 and TLR4 as well as TNF-α cytokine. Nitrosative stress was maximal in vehicle-treated infarcted hearts as evidenced by increased expression of iNOS, which was almost abolished after treatement with telmisartan. CONCLUSIONS Treatment of ZDF rats for 3 weeks with telmisartan, a dual angiotensin II receptor antagonist and partial PPAR-γ receptor agonist, resulted in a significant reduction of myocardial damage induced by I/R and was associated with increased adiponectin and a decrease in inflammatory markers.
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Affiliation(s)
- B Rinaldi
- Department of Experimental Medicine, Section of Pharmacology L. Donatelli, Second University of Naples, Via Costantinopoli 16, Naples, Italy
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Abstract
Male Zucker diabetic fatty fa/fa (ZDF) rats develop obesity and insulin resistance at a young age, and then with aging, progressively develop hyperglycemia. This hyperglycemia is associated with impaired pancreatic β-cell function, loss of pancreatic β-cell mass, and decreased responsiveness of liver and extrahepatic tissues to the actions of insulin and glucose. Of particular interest are the insights provided by studies of these animals into the mechanism behind the progressive impairment of carbohydrate metabolism. This feature among others, including the development of obesity- and hyperglycemia-related complications, is common between male ZDF rats and humans with type 2 diabetes associated with obesity. We discuss the diabetic features and complications found in ZDF rats and why these animals are widely used as a genetic model for obese type 2 diabetes.
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Affiliation(s)
- Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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Hata T, Mera Y, Kawai T, Ishii Y, Kuroki Y, Kakimoto K, Ohta T, Kakutani M. JTT-130, a novel intestine-specific inhibitor of microsomal triglyceride transfer protein, ameliorates impaired glucose and lipid metabolism in Zucker diabetic fatty rats. Diabetes Obes Metab 2011; 13:629-38. [PMID: 21362121 DOI: 10.1111/j.1463-1326.2011.01387.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AIM Microsomal triglyceride transfer protein (MTP) takes part in the mobilization of triglyceride-rich lipoproteins from enterocytes and hepatocytes. We investigated the effects of JTT-130, a novel intestine-specific MTP inhibitor, on impaired glucose and lipid metabolism in Zucker diabetic fatty (ZDF) rats. METHODS Male ZDF rats were fed a regular powdered diet with or without JTT-130 as a food admixture (0.01-0.02%) for 6 weeks. Food intake, body weight, blood biochemical parameters, fecal lipid contents, hepatic lipid contents, tissue mRNA levels and glucose utilization in adipose tissues were assessed. An intraperitoneal glucose tolerance test (IPGTT) and histological analysis of the pancreas were performed. RESULTS JTT-130 treatment decreased food intake, glycated hemoglobin, plasma levels of glucose, triglycerides and total cholesterol, hepatic levels of triglycerides and cholesterol and hepatic mRNA levels of glucose-6-phosphatase, phosphoenolpyruvate carboxykinase and fructose-1,6-bisphosphatase. JTT-130 treatment increased fecal levels of free fatty acids and cholesterol, plasma levels of glucagon-like peptide-1 and peptide YY, mRNA levels of glucose transporter 4 (GLUT4) and lipoprotein lipase in adipose tissues and GLUT4 in muscle and glucose utilization in adipose tissues. Plasma insulin decreased after 2 weeks and increased after 4 weeks of JTT-130 treatment. Plasma glucose in the JTT-130-treated rats was lower with higher plasma insulin than in the control rats during the IPGTT. The islets of the JTT-130-treated rats were larger and contained more insulin than those of the control rats. CONCLUSIONS JTT-130 ameliorates impaired glucose and lipid metabolism in the ZDF rats thereby suggesting that JTT-130 could be useful for prevention and treatment of type 2 diabetes.
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Affiliation(s)
- T Hata
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc, Osaka, Japan.
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Agil A, Navarro-Alarcón M, Ruiz R, Abuhamadah S, El-Mir MY, Vázquez GF. Beneficial effects of melatonin on obesity and lipid profile in young Zucker diabetic fatty rats. J Pineal Res 2011; 50:207-12. [PMID: 21087312 DOI: 10.1111/j.1600-079x.2010.00830.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The study objective was to investigate the effects of melatonin on obesity and obesity-associated systolic hypertension and dyslipidemia in young male Zucker diabetic fatty (ZDF) rats, an experimental model of the metabolic syndrome. ZDF rats (n=30) and lean littermates (ZL) (n=30) were used. At 6wk of age, both lean and fatty animals were subdivided into three groups (n=10): naive (N), vehicle-treated (V), and melatonin-treated (M) (10mg/kg/day) for 6wk. Vehicle and melatonin were added to the drinking water. Melatonin reduced mean weight gain (51±2/100g BW) versus N-ZDF group (58±3, P<0.05) without food intake differences. M-ZDF rats showed an apparent reduction in systolic hypertension that proved not to be statistically significant, and a significant improvement in dyslipidemia, with a reduction in hypertriglyceridemia from 580±40 to 420.6±40.9mg/dL (P<0.01). Melatonin raised high-density-lipoprotein (HDL) cholesterol in ZDF (from 81.6±4.9 to 103.1±4.5mg/dL, P<0.01) and ZL rats (from 62.8±4.8 to 73.5±4.8mg/dL, P<0.05) and significantly reduced low-density-lipoprotein (LDL) cholesterol in ZDF rats from 5.20±0.4 to 4.14±0.3 mg/dL (P<0.05) but had no effect on total cholesterol levels. To our knowledge, this is the first evidence of a positive effect of melatonin on overweight and lipid pattern of obese Zucker diabetic rats, supporting the proposition that melatonin administration may ameliorate overweight and lipid metabolism in humans. Because these benefits occurred in youth, before advanced metabolic and vascular complications, melatonin might help to prevent cardiovascular disease associated with obesity and dyslipidemia.
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Affiliation(s)
- Ahmad Agil
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain.
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Panchal SK, Brown L. Rodent models for metabolic syndrome research. J Biomed Biotechnol 2010; 2011:351982. [PMID: 21253582 PMCID: PMC3018657 DOI: 10.1155/2011/351982] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 12/01/2010] [Accepted: 12/02/2010] [Indexed: 02/07/2023] Open
Abstract
Rodents are widely used to mimic human diseases to improve understanding of the causes and progression of disease symptoms and to test potential therapeutic interventions. Chronic diseases such as obesity, diabetes and hypertension, together known as the metabolic syndrome, are causing increasing morbidity and mortality. To control these diseases, research in rodent models that closely mimic the changes in humans is essential. This review will examine the adequacy of the many rodent models of metabolic syndrome to mimic the causes and progression of the disease in humans. The primary criterion will be whether a rodent model initiates all of the signs, especially obesity, diabetes, hypertension and dysfunction of the heart, blood vessels, liver and kidney, primarily by diet since these are the diet-induced signs in humans with metabolic syndrome. We conclude that the model that comes closest to fulfilling this criterion is the high carbohydrate, high fat-fed male rodent.
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Affiliation(s)
- Sunil K. Panchal
- Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - Lindsay Brown
- Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, QLD 4350, Australia
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Lu M, Patsouris D, Li P, Flores-Riveros J, Frincke JM, Watkins S, Schenk S, Olefsky JM. A new antidiabetic compound attenuates inflammation and insulin resistance in Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2010; 298:E1036-48. [PMID: 20159859 PMCID: PMC2867370 DOI: 10.1152/ajpendo.00668.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tissue macrophage inflammatory pathways contribute to obesity-associated insulin resistance. Here, we have examined the efficacy and mechanisms of action of a novel anti-inflammatory compound (HE3286) in vitro and in vivo. In primary murine macrophages, HE3286 attenuates LPS- and TNFalpha-stimulated inflammation. In Zucker diabetic fatty rats, inflammatory cytokine/chemokine expression was downregulated in liver and adipose tissue by HE3286 treatment, as was macrophage infiltration into adipose tissue. In line with reduced inflammation, HE3286 treatment normalized fasting and fed glucose levels, improved glucose tolerance, and enhanced skeletal muscle and liver insulin sensitivity, as assessed by hyperinsulinemic euglycemic clamp studies. In phase 2 clinical trials, HE3286 treatment led to an enhancement in insulin sensitivity in humans. Gluconeogenic capacity was also reduced by HE3286 treatment, as evidenced by a reduced glycemic response during pyruvate tolerance tests and decreased basal hepatic glucose production (HGP) rates. Since serum levels of gluconeogenic substrates were decreased by HE3286, it indicates that the reduction of both intrinsic gluconeogenic capacity and substrate availability contributes to the decrease in HGP. Lipidomic analysis revealed that HE3286 treatment reduced liver cholesterol and triglyceride content, leading to a feedback elevation of LDL receptor and HMG-CoA reductase expression. Accordingly, HE3286 treatment markedly decreased total serum cholesterol. In conclusion, HE3286 is a novel anti-inflammatory compound, which displays both glucose-lowering and cholesterol-lowering effects.
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Affiliation(s)
- Min Lu
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0673, USA
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Wu L, Yang W, Jia X, Yang G, Duridanova D, Cao K, Wang R. Pancreatic islet overproduction of H2S and suppressed insulin release in Zucker diabetic rats. J Transl Med 2009; 89:59-67. [PMID: 19002107 DOI: 10.1038/labinvest.2008.109] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Hydrogen sulfide (H(2)S) has been traditionally known for its toxic effects on living organisms. The role of H(2)S in the homeostatic regulation of pancreatic insulin metabolism has been unclear. The present study is aimed at elucidating the effect of endogenously produced H(2)S on pancreatic insulin release and its role in diabetes development. Diabetes development in Zucker diabetic fatty (ZDF) rats was evaluated in comparison with Zucker fatty (ZF) and Zucker lean (ZL) rats. Pancreatic H(2)S production and insulin release were also assayed. It was found that H(2)S was generated in rat pancreas islets, catalyzed predominantly by cystathionine gamma-lyase (CSE). Pancreatic CSE expression and H(2)S production were greater in ZDF rats than in ZF or ZL rats. ZDF rats exhibited reduced serum insulin level, hyperglycemia, and insulin resistance. Inhibition of pancreatic H(2)S production in ZDF rats by intraperitoneal injection of DL-propargylglycine (PPG) for 4 weeks increased serum insulin level, lowered hyperglycemia, and reduced hemoglobin A1c level (P<0.05). Although in ZF rats it also reduced pancreatic H(2)S production and serum H(2)S level, PPG treatment did not alter serum insulin and glucose level. Finally, H(2)S significantly increased K(ATP) channel activity in freshly isolated rat pancreatic beta-cells. It appears that insulin release is impaired in ZDF because of abnormally high pancreatic production of H(2)S. New therapeutic approach for diabetes management can be devised based on our observation by inhibiting endogenous H(2)S production from pancreas.
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Affiliation(s)
- Lingyun Wu
- Department of Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
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Spielmann J, Stangl GI, Eder K. Dietary pea protein stimulates bile acid excretion and lowers hepatic cholesterol concentration in rats. J Anim Physiol Anim Nutr (Berl) 2008; 92:683-93. [PMID: 19012614 DOI: 10.1111/j.1439-0396.2007.00766.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
It has been shown that some dietary plant proteins beneficially influence lipid metabolism in animals. The effect of pea protein in this respect however has not yet been investigated. Therefore, we studied the effect of purified pea protein on the lipid metabolism in rats. Twenty-four rats received diets with either 200 g/kg of casein or purified pea protein for 16 days. Concentrations of triacylglycerols in liver, plasma and lipoproteins did not differ between both groups of rats. However, rats fed the pea protein diet had a lower concentration of total cholesterol in the liver and the very low density lipoproteins (VLDL) fraction than rats fed the casein diet (p < 0.05); cholesterol concentration in plasma, low density lipoproteins (LDL) and high density lipoproteins (HDL) did not differ between both groups. Rats fed pea protein moreover had an increased mRNA concentration of cholesterol-7alpha-hydroxylase in the liver and an increased amount of bile acids excreted via faeces compared with rats fed casein (p < 0.05). Concomitantly, mRNA concentrations of sterol regulatory element-binding protein (SREBP)-2 and its target genes 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and LDL receptor in the liver were increased in rats fed pea protein (p < 0.05). The data of this study suggests that pea protein stimulates formation and excretion of bile acids, which leads to a reduced hepatic cholesterol concentration and a reduced secretion of cholesterol via VLDL. An increased gene expression of SREBP-2 and its target genes HMG-CoA reductase and LDL receptor may be a means to compensate for the increased loss of cholesterol for bile acid synthesis.
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Affiliation(s)
- J Spielmann
- Institute of Agricultural and Nutritional Sciences, Martin-Luther-University of Halle-Wittenberg, Halle, Saale, Germany
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Lesniewski LA, Donato AJ, Behnke BJ, Woodman CR, Laughlin MH, Ray CA, Delp MD. Decreased NO signaling leads to enhanced vasoconstrictor responsiveness in skeletal muscle arterioles of the ZDF rat prior to overt diabetes and hypertension. Am J Physiol Heart Circ Physiol 2008; 294:H1840-50. [PMID: 18245568 PMCID: PMC2646849 DOI: 10.1152/ajpheart.00692.2007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Approximately 40% of patients with type 2 diabetes present with concurrent hypertension at the time of diabetes diagnosis. Increases in peripheral vascular resistance and correspondingly enhanced vasoconstrictor capacity could have profound implications for the development of hypertension and the progression of insulin resistance to overt diabetes. The purpose of this study was to determine whether skeletal muscle arteriolar vasoconstrictor dysfunction precedes or occurs concurrently with the onset of diabetes and hypertension. Male Zucker diabetic fatty (ZDF) rats were studied at 7, 13, and 20 wk of age to represent prediabetic and short-term and long-term diabetic states, respectively. Conscious mean arterial pressure (MAP), fasted plasma insulin and glucose, vasoconstrictor responses, and passive mechanical properties of isolated skeletal muscle arterioles were measured in prediabetic, diabetic, and age-matched control rats. Elevated MAP was manifest in short-term diabetes (control 117 +/- 1, diabetic 135 +/- 3 mmHg) and persisted with long-term diabetes (control 113 +/- 2, diabetic 135 +/- 3 mmHg). This higher MAP was preceded by augmented arteriolar vasoconstrictor responses to norepinephrine and endothelin-1 and followed by diminished beta-adrenergic vasodilation and enhanced myogenic constriction in long-term diabetes. Furthermore, we demonstrate that diminished nitric oxide (NO) signaling underlies the increases in vasoconstrictor responsiveness in arterioles from prediabetic and diabetic rats. Arteriolar stiffness was not different between control and prediabetic or diabetic rats at any time point studied. Collectively, these results indicate that increases in vasoconstrictor responsiveness resulting from diminished NO signaling in skeletal muscle arterioles precede the development of diabetes and hypertension in ZDF rats.
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Affiliation(s)
- Lisa A Lesniewski
- Dept. of Health and Kinesiology, Texas A & M University, College Station, Texas, USA
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Spielmann J, Shukla A, Brandsch C, Hirche F, Stangl GI, Eder K. Dietary lupin protein lowers triglyceride concentrations in liver and plasma in rats by reducing hepatic gene expression of sterol regulatory element-binding protein-1c. ANNALS OF NUTRITION AND METABOLISM 2007; 51:387-92. [PMID: 17785965 DOI: 10.1159/000107720] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 05/02/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND Recently, it has been shown that dietary lupin protein lowers plasma triglyceride concentrations in rats. In this study, we investigated the hypothesis that this effect is due to a downregulation of sterol regulatory element-binding protein (SREBP)-1c, a transcription factor that regulates the expression of lipogenic enzymes in the livers of rats. METHODS Two groups of 12 rats each were fed semisynthetic diets containing 200 g/kg of either casein (control group) or lupin protein from Lupinus albus for 22 days. RESULTS Rats fed the diet containing lupin protein had lower concentrations of triglycerides in the liver, plasma and VLDL + chylomicrons (p < 0.05). The concentration of protein in VLDL + chylomicrons was also lower in rats fed lupin protein than in rats fed casein (p < 0.05). The mRNA concentrations of SREBP-1c and fatty acid synthase in the liver were lower in rats fed lupin protein than in rats fed casein (p < 0.05). The mRNA concentrations of lipoprotein lipase in the liver did not differ between both groups of rats. CONCLUSION This study confirms that a protein isolated from L. albus is strongly hypotriglyceridemic in rats. It is shown for the first time that this effect is at least in part due to a downregulation of SREBP-1c in the liver which in turn leads to a reduction in hepatic fatty acid synthesis.
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Affiliation(s)
- Julia Spielmann
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
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Brandsch C, Shukla A, Hirche F, Stangl GI, Eder K. Effect of proteins from beef, pork, and turkey meat on plasma and liver lipids of rats compared with casein and soy protein. Nutrition 2006; 22:1162-70. [PMID: 16979322 DOI: 10.1016/j.nut.2006.06.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 06/26/2006] [Accepted: 06/30/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE We assessed the effect of dietary proteins isolated from beef, pork, and turkey meat on concentrations of cholesterol and triacylglycerols in plasma, lipoproteins, and liver and the composition of the microsomal membrane (fatty acids, phosphatidylcholine/phosphatidylethanolamine ratio) compared with that of casein and soy protein in rats. METHODS Five groups of 12 rats each were fed semisynthetic diets for 20 d that contained 200 g/kg of proteins isolated from beef, pork, or turkey meat or, as controls, casein or soy protein. RESULTS Rats fed beef, pork, or turkey proteins did not differ in cholesterol concentrations of plasma, lipoproteins, and liver and in composition of microsomal membrane from rats fed the casein diet. All groups fed a protein from an animal source had higher very low-density lipoprotein (VLDL) and liver cholesterol concentrations than did rats fed soy protein. However, rats fed pork protein had lower concentrations of triacylglycerols in liver, plasma, and VLDL and lower mRNA concentrations of sterol regulatory element binding protein-1 and glucose-6-phosphate dehydrogenase than did rats fed casein. However, concentrations of plasma and VLDL triacylglycerols in rats fed pork protein were not as low as those observed in rats fed soy protein. CONCLUSION Proteins isolated from beef, pork, or turkey meat do not differ from casein in their effects on cholesterol metabolism. Pork protein decreases plasma triacylglycerol concentrations compared with casein but not compared with soy protein. The triacylglycerol-lowering effect of pork protein compared with casein is suggested to be caused by decreased hepatic fatty acid synthesis.
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Affiliation(s)
- Corinna Brandsch
- Institute of Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany
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van Lunteren E, Moyer M. Altered diaphragm muscle action potentials in zucker diabetic fatty (ZDF) rats. Respir Physiol Neurobiol 2006; 153:157-65. [PMID: 16311078 DOI: 10.1016/j.resp.2005.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 08/31/2005] [Accepted: 09/01/2005] [Indexed: 10/25/2022]
Abstract
The Zucker diabetic fatty (ZDF) rat is a model of type 2 diabetes, being characterized by obesity, diabetes, and dyslipidemia. In vitro studies tested the hypothesis that diaphragm muscle from ZDF rats has abnormal resting membrane potential and action potentials, similar to type 1 diabetic rodents. Resting membrane potential was comparable for muscle from ZDF and control rats. Diaphragm from ZDF rats had augmented action potential peak height (92.1 mV versus 82.4 mV, P<0.00001), overshoot (15.6 mV versus 8.1 mV, P<0.001) and area (80.7 mV ms versus 68.6 mV ms, P<0.001) compared with that from controls. Action potential rate of depolarization and repolarization were not affected. The K(+) blocker, 3,4-diaminopyridine, augmented action potential duration and area of muscle from ZDF and controls, but without significant differences between animal groups. These findings in ZDF rats contrast with type 1 diabetic rats, suggesting that isolated hyperglycemia differs from hyperglycemia combined with other metabolic perturbations with respect to diaphragm electrophysiological derangements.
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Affiliation(s)
- Erik van Lunteren
- Department of Medicine (Pulmonary and Critical Care Division), Cleveland VA Medical Center and Case Western Reserve University, 10701 East Boulevard, Cleveland, OH 44106, USA.
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Eid A, Bodin S, Ferrier B, Delage H, Boghossian M, Martin M, Baverel G, Conjard A. Intrinsic gluconeogenesis is enhanced in renal proximal tubules of Zucker diabetic fatty rats. J Am Soc Nephrol 2006; 17:398-405. [PMID: 16396963 DOI: 10.1681/asn.2005070742] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Recent studies indicate that renal gluconeogenesis is substantially stimulated in patients with type 2 diabetes, but the mechanism that is responsible for such stimulation remains unknown. Therefore, this study tested the hypothesis that renal gluconeogenesis is intrinsically elevated in the Zucker diabetic fatty rat, which is considered to be an excellent model of type 2 diabetes. For this, isolated renal proximal tubules from diabetic rats and from their lean nondiabetic littermates were incubated in the presence of physiologic gluconeogenic precursors. Although there was no increase in substrate removal and despite a reduced cellular ATP level, a marked stimulation of gluconeogenesis was observed in diabetic relative to nondiabetic rats, with near-physiologic concentrations of lactate (38%), glutamine (51%) and glycerol (66%). This stimulation was caused by a change in the fate of the substrate carbon skeletons resulting from an increase in the activities and mRNA levels of the key gluconeogenic enzymes that are common to lactate, glutamine, and glycerol metabolism, i.e., mainly of phosphoenolpyruvate carboxykinase and, to a lesser extent, of glucose-6-phosphatase and fructose-1,6-bisphosphatase. Experimental evidence suggests that glucocorticoids and cAMP were two factors that were responsible for the long-term stimulation of renal gluconeogenesis observed in the diabetic rats. These data provide the first demonstration in an animal model that renal gluconeogenesis is upregulated by a long-term mechanism during type 2 diabetes. Together with the increased renal mass (38%) observed, they lend support to the view so far based only on in vivo studies performed in humans that renal gluconeogenesis may be stimulated by and crucially contribute to the hyperglycemia of type 2 diabetes.
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Affiliation(s)
- Assaad Eid
- Laboratoire de Physiopathologie Métabolique et Rénale, INSERM UMR 499, Faculté de Médecine R.T.H. Laennec, rue G. Paradin, 69372 Lyon Cedex 08, France
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30
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Carley AN, Severson DL. Fatty acid metabolism is enhanced in type 2 diabetic hearts. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1734:112-26. [PMID: 15904868 DOI: 10.1016/j.bbalip.2005.03.005] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 03/11/2005] [Accepted: 03/22/2005] [Indexed: 12/30/2022]
Abstract
The metabolic phenotype of hearts has been investigated using rodent models of type 2 diabetes which exhibit obesity and insulin resistance: db/db and ob/ob mice, and Zucker fatty and ZDF rats. In general, cardiac fatty acid (FA) utilization is enhanced in type 2 diabetic hearts, with increased rates of FA oxidation (db/db, ob/ob and ZDF models) and increased FA esterification into cellular triacylglycerols (db/db hearts). Hearts from db/db and ob/ob mice and ZDF rat hearts all have elevated levels of myocardial triacylglycerols, consistent with enhanced FA utilization. A number of mechanisms may be responsible for enhanced FA utilization in type 2 diabetic hearts: (i) increased FA uptake into cardiac myocytes and into mitochondria; (ii) altered mitochondrial function, with up-regulation of uncoupling proteins; and (iii) stimulation of peroxisome proliferator-activated receptor-alpha. Enhanced cardiac FA utilization in rodent type 2 diabetic models is associated with reduced cardiac contractile function, perhaps as a consequence of lipotoxicity and/or reduced cardiac efficiency. Similar results have been obtained with human type 2 diabetic hearts, suggesting that pharmacological interventions that can reduce cardiac FA utilization may have beneficial effects on contractile function.
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Affiliation(s)
- Andrew N Carley
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, Canada T2N 4N1
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Chirieac DV, Collins HL, Cianci J, Sparks JD, Sparks CE. Altered triglyceride-rich lipoprotein production in Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2004; 287:E42-9. [PMID: 14970003 DOI: 10.1152/ajpendo.00297.2003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Triglyceride-rich lipoprotein (TRL) production was studied in Zucker diabetic fatty (ZDF) rats, a model of insulin-resistant type 2 diabetes progression. TRL production was measured in vivo by blocking catabolism with Triton WR-1339. Ten-week ZDF rats are hyperinsulinemic with increased TRL production [both triglyceride and apolipoprotein B (apoB)]. Twenty-week ZDF rats are insulinopenic, and TRL production is similar to lean controls. Insulin infusion suppresses glucose and free fatty acids in 10- and 20-wk ZDF rats. Increased TRL production is not reduced by insulin in 10-wk rats; however, at 20 wk, TRL production is suppressed by insulin. In vitro studies with hepatocytes derived from 10-wk ZDF rats showed minimal insulin dose effects on apoB secretion compared with the response and sensitivity of hepatocytes derived from 20-wk ZDF and control lean rats. Hepatic sterol regulatory-binding protein (SREBP)-1c mRNA levels are increased at 10 wk but return to control levels at 20 wk. ApoB mRNA levels are similar to lean controls at 10 and 20 wk. The following two mechanisms for hypertriglyceridemia associated with hyperinsulinemia are suggested: increased TRL synthesis and loss of TRL suppression. Increased triglyceride production in hyperinsulinemic rats likely relates to increased expression of SREBP-1c, whereas increased apoB production involves posttranscriptional processes.
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Affiliation(s)
- Doru V Chirieac
- Dept. of Pathology and Laboratory Medicine, Univ. of Rochester School of Medicine & Dentistry, P. O. Box 626, 601 Elmwood Ave., Rochester, New York 14642, USA
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Wang P, Chatham JC. Onset of diabetes in Zucker diabetic fatty (ZDF) rats leads to improved recovery of function after ischemia in the isolated perfused heart. Am J Physiol Endocrinol Metab 2004; 286:E725-36. [PMID: 14722022 DOI: 10.1152/ajpendo.00295.2003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [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 whether the transition from insulin resistance to hyperglycemia in a model of type 2 diabetes leads to intrinsic changes in the myocardium that increase the sensitivity to ischemic injury. Hearts from 6-, 12-, and 24-wk-old lean (Control) and obese Zucker diabetic fatty (ZDF) rats were isolated, perfused, and subjected to 30 min of low-flow ischemia (LFI) and 60 min of reperfusion. At 6 wk, ZDF animals were insulin resistant but not hyperglycemic. By 12 wk, the ZDF group was hyperglycemic and became progressively worse by 24 wk. In spontaneously beating hearts rate-pressure product (RPP) was depressed in the ZDF groups compared with age-matched Controls, primarily due to lower heart rate. Pacing significantly increased RPP in all ZDF groups; however, this was accompanied by a significant decrease in left ventricular developed pressure. There was also greater contracture during LFI in the ZDF groups compared with the Control group; surprisingly, however, functional recovery upon reperfusion was significantly higher in the diabetic 12- and 24-wk ZDF groups compared with age-matched Control groups and the 6-wk ZDF group. This improvement in recovery in the ZDF diabetic groups was independent of substrate availability, severity of ischemia, and duration of diabetes. These data demonstrate that, although the development of type 2 diabetes leads to progressive contractile and metabolic abnormalities during normoxia and LFI, it was not associated with increased susceptibility to ischemic injury.
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Affiliation(s)
- Peipei Wang
- Division of Cardiovascular Disease, Department of Medicine, The Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Al 35294-0005, USA
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Evert M, Schneider-Stock R, Dombrowski F. Apolipoprotein A-IV mRNA overexpression in early preneoplastic hepatic foci induced by low-number pancreatic islet transplants in streptozotocin-diabetic rats. Pathol Res Pract 2003; 199:373-9. [PMID: 12924437 DOI: 10.1078/0344-0338-00433] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
After low-number transplantation of islets of Langerhans into the liver of streptozotocin-diabetic rats, the hepatocytes in the acini, draining the blood from the islets, are exposed to a local hyperinsulinemia, whereas the remaining tissue is affected by hypoinsulinemia. In this model, insulin induces alterations that resemble preneoplastic foci of altered hepatocytes (FAH) and develop into hepatocellular tumors in later stages of carcinogenesis. In rodents, apolipoprotein A-IV (A-IV) is synthesized in the small intestine and the liver. Whereas intestinal production is mainly influenced by lipid intake and chylomicrone formation, little is known about mechanisms regulating hepatic A-IV synthesis. As it is known that insulin modulates lipoprotein metabolism in different ways, we investigated the effect of insulin on hepatocytic A-IV mRNA expression in this model. After Laser microdissection of FAH and quantitative RT-PCR (LightCycler), we found a 3.2 to 7.4-fold increase of A-IV mRNA in the FAH. To the best of our knowledge, these results represent the first data of insulin-stimulated A-IV mRNA overexpression in rat hepatocytes in vivo, and are in line with previously reported results of experiments with cultured hepatocytes. It remains to be elucidated whether A-IV mRNA overexpression is only an epiphenomenon of insulin action or is relevant for hepatocarcinogenesis in this model.
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Affiliation(s)
- Matthias Evert
- Department of Pathology, Otto-von-Guericke-University, Magdeburg, Germany.
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Kearney T, de Gallegos CN, Proudler A, Parker K, Anayaoku V, Bannister P, Venkatesan S, Johnston DG. Effects of short- and long-term growth hormone replacement on lipoprotein composition and on very-low-density lipoprotein and low-density lipoprotein apolipoprotein B100 kinetics in growth hormone-deficient hypopituitary subjects. Metabolism 2003; 52:50-9. [PMID: 12524662 DOI: 10.1053/meta.2003.50061] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study, we concurrently examined the effects of 8 and 40 weeks of growth hormone replacement (GHR) on lipids, lipoprotein composition, low-density lipoprotein (LDL) size, very-low-density lipoprotein (VLDL) apolipoprotein (apo)B kinetics and LDL apoB kinetics. Eight weeks of GHR did not alter lipid profiles. Forty weeks of GHR increased high-density lipoprotein-cholesterol (HDL-C) concentration (P =.01), nonsignificantly reduced LDL-C (P =.06), and reduced the HDL/LDL-C ratio (P =.04). Forty weeks of GHR increased HDL free cholesterol (P =.03), total cholesterol (P =.01), and cholesterol ester (P <.01) concentrations. No other significant changes in VLDL, LDL, or HDL composition or LDL size were noted at any time. Eight weeks of GHR reduced VLDL apoB absolute secretion rate (ASR, P =.03), with nonsignificant reductions in fractional secretion rate (FSR, P =.09) and pool size (P =.09). After 40 weeks of GHR, the VLDL apoB ASR, FSR, and pool size were not significantly different from baseline. Forty weeks of GHR increased both LDL apoB FSR (P =.02) and LDL apoB ASR (P =.04), with a small decrease in pool size. Thus, GHR may have important antiatherogenic effects; HDL-C increased, LDL-C was nonsignificantly reduced, the total/HDL-C ratio was reduced, VLDL apoB production was reduced, and LDL apoB turnover was increased.
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Affiliation(s)
- Tara Kearney
- Department of Metabolic Medicine, St. Mary's Hospital Campus, London, UK
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Fujinami K, Kojima K, Aragane K, Kusunoki J. Postprandial hyperlipidemia in Zucker diabetic fatty fa/fa rats, an animal model of type II diabetes, and its amelioration by acyl-CoA:cholesterol acyltransferase inhibition. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 86:127-9. [PMID: 11430465 DOI: 10.1254/jjp.86.127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Postprandial hyperlipidemia (PH) is frequently observed in diabetic patients. We performed an oral fat-loading test in Zucker diabetic fatty (ZDF) fa/fa rats, a model for type II diabetes, to determine whether PH was induced in the rats. Post fat-loading changes in serum cholesterol and triglyceride levels were significantly greater in the fa/fa rats than those seen in their lean littermates and an acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor significantly reduced these levels by 24% and 31%, respectively. Therefore, we confirmed that PH appeared in ZDF fa/fa rats by fat loading and ACAT inhibition may be a potential treatment for PH.
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Affiliation(s)
- K Fujinami
- Central Research Laboratories, Fujirebio Inc., Hachioji, Tokyo, Japan.
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Sparks JD, Shaw WN, Corsetti JP, Bolognino M, Pesek JF, Sparks CE. Insulin-treated Zucker diabetic fatty rats retain the hypertriglyceridemia associated with obesity. Metabolism 2000; 49:1424-30. [PMID: 11092505 DOI: 10.1053/meta.2000.17736] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lipoprotein and apolipoprotein changes were evaluated in 10-week-old Zucker diabetic fatty (ZDF) male rats following 12 weeks of insulin treatment, which normalized blood glucose and maintained weight gaining characteristic of nondiabetic Zucker fatty rats. Compared with untreated ZDF rats (saline-injected), insulin treatment resulted in increased very-low-density lipoprotein (VLDL; d < 1.006 g/mL) and decreased alpha lipoprotein on agarose gel electrophoresis. These findings were consistent with an observed increase in VLDL triglyceride and cholesterol, and decreased high-density lipoprotein (HDL) cholesterol with insulin treatment in isolated lipoproteins. B100 levels were unchanged by insulin treatment, but B48 levels were significantly increased in the VLDL fraction. Insulin treatment depressed apolipoprotein (apo) A-I levels in HDL, but had little effect on total apo E, apo A-IV, or apo C, although apo C was redistributed to the VLDL fraction. These results suggest that insulin treatment of ZDF rats normalizes hyperglycemia and prevents age-related changes in lipoprotein parameters associated with development of insulinopenic diabetes. Insulin therapy in ZDF rats thereby sustains the hyperlipidemic lipoprotein pattern associated with hyperinsulinemia and obesity.
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Affiliation(s)
- J D Sparks
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, NY, USA
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Stevenson FT, Wheeldon CM, Gades MD, Kaysen GA, Stern JS, van Goor H. Estrogen worsens incipient hypertriglyceridemic glomerular injury in the obese Zucker rat. Kidney Int 2000; 57:1927-35. [PMID: 10792611 DOI: 10.1046/j.1523-1755.2000.00042.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The obese Zucker rat (OZR) is a model of glomerulosclerosis and renal failure in the setting of hyperlipidemia, hyperinsulinemia, and obesity. Our prior work in OZRs has shown that ovariectomy attenuates glomerulosclerosis, while added estrogen worsens it. To investigate the mechanism of estrogen's effects on glomerular disease in this model, we evaluated the effects of ovariectomy and estrogen supplementation on seven-week peripubertal OZRs. At this time point, rats exhibit no overt histologic glomerular disease, but are just beginning to show elevated urinary albumin excretion. METHODS Female OZRs fed ad libitum were ovariectomized at four weeks, with or without estrogen supplementation to raise estrogen levels to just below those of preoestral adults (mean 16.5 pg/mL). Sham-operated controls were included. RESULTS Ovariectomy normalized albuminuria, lowered total and very low-density lipoprotein triglycerides, and reduced glomerular fibronectin expression. Estrogen supplementation worsened albuminuria and raised total/very low-density lipoprotein triglycerides and total cholesterol. Estrogen-supplemented rats exhibited enhanced glomerular deposition of apo A-IV and apo B, increased glomerular expression of desmin and type IV collagen, and increased interstitial macrophage deposition. CONCLUSION Estrogen may be permissive for the early development of renal disease in OZRs and may act by increasing triglyceride-rich lipoproteins, which then bind to glomerular cells and initiate or accelerate glomerulosclerosis.
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Affiliation(s)
- F T Stevenson
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, School of Medicine, University of California, Davis 95616, USA.
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Corsetti JP, Sparks JD, Peterson RG, Smith RL, Sparks CE. Effect of dietary fat on the development of non-insulin dependent diabetes mellitus in obese Zucker diabetic fatty male and female rats. Atherosclerosis 2000; 148:231-41. [PMID: 10657558 DOI: 10.1016/s0021-9150(99)00265-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The obese Zucker diabetic fatty male rat (ZDF/Gmi¿trade mark omitted¿-fa) has become a widely used animal model of NIDDM, in contrast to the obese ZDF females that rarely develop NIDDM. However, preliminary observations suggest that obese ZDF females may become diabetic on high-fat diets. Therefore, we studied the effect of dietary fat on development of NIDDM, dyslipidemia, and alterations in organ-specific serum panels in obese ZDF males and females. Results indicated different effects of dietary fat-content on development of diabetes in males and females. Males, even on low fat-content diets, developed diabetes but the process was accelerated as a function of dietary fat-content, whereas only the highest fat-content diet induced development of NIDDM in obese ZDF females. Additionally, triglyceride/apolipoprotein B ratios demonstrated gender-specific differences in the nature of circulating lipoprotein particles independent of diabetic state with values for females approximately twice those of males indicating more highly triglyceride-enriched lipoprotein particles in females. We conclude that the obese ZDF female rat has the potential to become an important animal model of NIDDM especially in women where few models currently exist.
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Affiliation(s)
- J P Corsetti
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
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