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Relationship Between Myocardial Injury and Expression of PGC-1α and Its Coactivators in Chronic Keshan Disease. Curr Med Sci 2021; 42:85-92. [PMID: 34705216 DOI: 10.1007/s11596-021-2454-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Keshan disease (KD) is a mitochondrial cardiomyopathy. The present study explored the roles of peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), the key regulator of mitochondrial structure and function, and its coactivators in myocardial injury in chronic KD. Furthermore, the usefulness of these molecules in the diagnosis of chronic KD was assessed. METHODS In the present case-control study, 43 patients with chronic KD and 30 healthy individuals living in KD endemic areas were included. The myocardial injury indicators and mRNA expression levels of PGC-1α, nuclear respiratory factor 1 (NRF1), PPARα, and estrogen-related receptor alpha (ERRα) in peripheral blood were examined. RESULTS It was found that the levels of atrial natriuretic peptide, creatine kinase, and lactate dehydrogenase (LDH) were higher in patients with chronic KD, when compared to controls, while the level of bradykinin was lower. Furthermore, the PGC-1α, NRF1 and PPARα mRNA levels were higher in patients with KD. The area under the receiver operating characteristic curve and the optimal diagnostic threshold of LDH was 0.937 and 304.0 U/L, respectively. It is noteworthy that the area under the combined receiver operating characteristic curve was larger, when compared to that for LDH detection alone (Z=2.055, P=0.0399). The area under the curve for the "LDH+PPARα" combination was 0.984, with 96.7% sensitivity and 93.0% specificity. CONCLUSION The combined detection of LDH and the expression of PPARα can be performed to diagnose the chronic KD.
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2
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Ali A, Wang Y, Wu L, Yang G. Gasotransmitter signaling in energy homeostasis and metabolic disorders. Free Radic Res 2020; 55:83-105. [PMID: 33297784 DOI: 10.1080/10715762.2020.1862827] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Gasotransmitters are small molecules of gases, including nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO). These three gasotransmitters can be endogenously produced and regulate a wide range of pathophysiological processes by interacting with specific targets upon diffusion in the biological media. By redox and epigenetic regulation of various physiological functions, NO, H2S, and CO are critical for the maintenance of intracellular energy homeostasis. Accumulated evidence has shown that these three gasotransmitters control ATP generation, mitochondrial biogenesis, glucose metabolism, insulin sensitivity, lipid metabolism, and thermogenesis, etc. Abnormal generation and metabolism of NO, H2S, and/or CO are involved in various abnormal metabolic diseases, including obesity, diabetes, and dyslipidemia. In this review, we summarized the roles of NO, H2S, and CO in the regulation of energy homeostasis as well as their involvements in the metabolism of dysfunction-related diseases. Understanding the interaction among these gasotransmitters and their specific molecular targets are very important for therapeutic applications.
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Affiliation(s)
- Amr Ali
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Yuehong Wang
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Lingyun Wu
- Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada.,School of Human Kinetics, Laurentian University, Sudbury, Canada.,Health Science North Research Institute, Sudbury, Canada
| | - Guangdong Yang
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Canada.,Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
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3
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Ferver A, Dridi S. Regulation of avian uncoupling protein (av-UCP) expression by cytokines and hormonal signals in quail myoblast cells. Comp Biochem Physiol A Mol Integr Physiol 2020; 248:110747. [PMID: 32565233 DOI: 10.1016/j.cbpa.2020.110747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/05/2020] [Accepted: 06/16/2020] [Indexed: 01/20/2023]
Abstract
Uncoupling proteins (UCPs), members of the mitochondrial anion carrier family, play a pivotal role in thermogenesis, redox balance, reactive oxygen species and many other cellular processes. They were extensively studied in mammalian species and have been shown to be tightly regulated at transcriptional and translational levels by various environmental and hormonal factors. Such studies are very limited in avian species which represent a unique model because they lack brown adipose tissue and they contain only one UCP (av-UCP) predominantly expressed in the muscle. The present study aimed, therefore, to determine the effects of pro-inflammatory cytokines (IL-6 and TNFα) and energy homeostasis-related hormones (leptin and T3) on the expression of av-UCP and its related transcription factors in quail myoblast (QM7) cells. Leptin treatment for 24 h significantly down-regulated av-UCP, and up-regulated PGC-1α, PPARα, and PPARγ expression in QM7 cells. IL-6 and TNFα administration significantly up-regulated the expression of av-UCP, however T3 had a biphasic effects (up-regulation with low dose and down-regulation with high dose) on av-UCP mRNA levels (P < .05). TNFα significantly induced PPARα and PPARγ mRNA abundances, however T3 and IL-6 down-regulated PPARα expression (P < .05). Together, these data are the first to report cytokine and hormonal regulation of av-UCP in avian muscle cells, suggesting that these effects are mediated through PPARs and PGC-1α, and opening a new vista for future functional and mechanistic studies.
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Affiliation(s)
- Alison Ferver
- University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, AR 72701, United States of America
| | - Sami Dridi
- University of Arkansas, Center of Excellence for Poultry Science, Fayetteville, AR 72701, United States of America.
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4
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Gheibi S, Samsonov AP, Gheibi S, Vazquez AB, Kashfi K. Regulation of carbohydrate metabolism by nitric oxide and hydrogen sulfide: Implications in diabetes. Biochem Pharmacol 2020; 176:113819. [PMID: 31972170 DOI: 10.1016/j.bcp.2020.113819] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/15/2020] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) and hydrogen sulfide (H2S) are two gasotransmitters that are produced in the human body and have a key role in many of the physiological activities of the various organ systems. Decreased NO bioavailability and deficiency of H2S are involved in the pathophysiology of type 2 diabetes and its complications. Restoration of NO levels have favorable metabolic effects in diabetes. The role of H2S in pathophysiology of diabetes is however controversial; H2S production is decreased during development of obesity, diabetes, and its complications, suggesting the potential therapeutic effects of H2S. On the other hand, increased H2S levels disturb the pancreatic β-cell function and decrease insulin secretion. In addition, there appear to be important interactions between NO and H2S at the levels of both biosynthesis and signaling pathways, yet clear an insight into this relationship is lacking. H2S potentiates the effects of NO in the cardiovascular system as well as NO release from its storage pools. Likewise, NO increases the activity and the expression of H2S-generating enzymes. Inhibition of NO production leads to elimination/attenuation of the cardioprotective effects of H2S. Regarding the increasing interest in the therapeutic applications of NO or H2S-releasing molecules in a variety of diseases, particularly in the cardiovascular disorders, much is to be learned about their function in glucose/insulin metabolism, especially in diabetes. The aim of this review is to provide a better understanding of the individual and the interactive roles of NO and H2S in carbohydrate metabolism.
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Affiliation(s)
- Sevda Gheibi
- Department of Clinical Sciences in Malmö, Unit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden.
| | - Alan P Samsonov
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA
| | - Shahsanam Gheibi
- Maternal and Childhood Obesity Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Alexandra B Vazquez
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA
| | - Khosrow Kashfi
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA; Graduate Program in Biology, City University of New York Graduate Center, New York, NY, USA.
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5
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Becerril S, Rodríguez A, Catalán V, Ramírez B, Unamuno X, Portincasa P, Gómez-Ambrosi J, Frühbeck G. Functional Relationship between Leptin and Nitric Oxide in Metabolism. Nutrients 2019; 11:nu11092129. [PMID: 31500090 PMCID: PMC6769456 DOI: 10.3390/nu11092129] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/23/2019] [Accepted: 09/02/2019] [Indexed: 12/28/2022] Open
Abstract
Leptin, the product of the ob gene, was originally described as a satiety factor, playing a crucial role in the control of body weight. Nevertheless, the wide distribution of leptin receptors in peripheral tissues supports that leptin exerts pleiotropic biological effects, consisting of the modulation of numerous processes including thermogenesis, reproduction, angiogenesis, hematopoiesis, osteogenesis, neuroendocrine, and immune functions as well as arterial pressure control. Nitric oxide (NO) is a free radical synthesized from L-arginine by the action of the NO synthase (NOS) enzyme. Three NOS isoforms have been identified: the neuronal NOS (nNOS) and endothelial NOS (eNOS) constitutive isoforms, and the inducible NOS (iNOS). NO mediates multiple biological effects in a variety of physiological systems such as energy balance, blood pressure, reproduction, immune response, or reproduction. Leptin and NO on their own participate in multiple common physiological processes, with a functional relationship between both factors having been identified. The present review describes the functional relationship between leptin and NO in different physiological processes.
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Affiliation(s)
- Sara Becerril
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
| | - Amaia Rodríguez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
| | - Victoria Catalán
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
| | - Beatriz Ramírez
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
| | - Xabier Unamuno
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Medical Engineering Laboratory, University of Navarra, 31008 Pamplona, Spain.
| | - Piero Portincasa
- Clinica Medica "A. Murri", Department of Biomedical Sciences and Human Oncology, University of Bari Medical School, Policlinico Hospital, 70124 Bari, Italy.
| | - Javier Gómez-Ambrosi
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
| | - Gema Frühbeck
- Metabolic Research Laboratory, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 31008 Pamplona, Spain.
- Obesity and Adipobiology Group, Instituto de Investigación Sanitaria de Navarra (IdiSNA), 31008 Pamplona, Spain.
- Department of Endocrinology & Nutrition, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
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6
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Garcia-Diaz DF, Jimenez P, Reyes-Farias M, Soto-Covasich J, Costa AGV. A Review of the Potential of Chilean Native Berries in the Treatment of Obesity and its Related Features. PLANT FOODS FOR HUMAN NUTRITION (DORDRECHT, NETHERLANDS) 2019; 74:277-286. [PMID: 31278560 DOI: 10.1007/s11130-019-00746-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Obesity is a major worldwide health threat. It is characterized by an abnormal adipose tissue overgrowth together with increased monocytes infiltration, causing inflammation and oxidative stress, events associated with several illnesses. Investigations have focused on the benefits of native fruit consumption, claiming these to be natural sources of bioactive compounds with antioxidant and anti-inflammatory characteristics. It has been widely stated that berries are a source of the most antioxidant compounds, and, thus, seem highly promising to endure research efforts on these vegetal matrices. The present article describes botanical, chemical and biomedical features of the Chilean native berries, Aristotelia chilensis, Ugni molinae, and Berberis microphylla. This work aims to potentiate incoming research focused on the search for novel treatments for first-order diseases with these particular plant sources.
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Affiliation(s)
- Diego F Garcia-Diaz
- Department of Nutrition, School of Medicine, University of Chile, Independencia, 1027, Santiago, Chile.
| | - P Jimenez
- Department of Nutrition, School of Medicine, University of Chile, Independencia, 1027, Santiago, Chile
| | - M Reyes-Farias
- Department of Nutrition, School of Medicine, University of Chile, Independencia, 1027, Santiago, Chile
| | - J Soto-Covasich
- Biotechnology Doctoral Program, Pontificia Universidad Catolica de Valparaiso - Universidad Tecnica Federico Santa Maria, Valparaiso, Chile
| | - A G V Costa
- Department of Pharmacy and Nutrition, Centre of Exact, Natural and Health Sciences, Federal University of Espirito Santo, Alegre, Brazil
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7
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Zheng S, Zhao J, Xing H, Xu S. Oxidative stress, inflammation, and glycometabolism disorder-induced erythrocyte hemolysis in selenium-deficient exudative diathesis broilers. J Cell Physiol 2019; 234:16328-16337. [PMID: 30741419 DOI: 10.1002/jcp.28298] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/04/2018] [Accepted: 12/10/2018] [Indexed: 01/24/2023]
Abstract
Selenium (Se) deficiency causes injury of diversified tissues and cells, including livers, hearts, skeletal muscles, and erythrocytes. The aim of the present study is to explore the molecular mechanism of erythrocyte hemolysis due to Se deficiency in broilers. One hundred and eighty broilers (male/female, 1 day old) were randomly divided into two groups and fed with either a normal Se content diet (C group, 0.2 mg Se/kg) or a Se-deficient diet (ED group, 0.008 mg Se/kg) for 45 days. During the trial period of 15-30 days, biological properties such as osmotic fragility, fluidity, phospholipid components of cell membrane, adenosine triphosphatase activities, and antioxidant function of erythrocytes in broilers were examined. Moreover, the messenger RNA (mRNA) expressions of genes associated with inflammation, glycometabolism, and avian uncoupling protein (avUCP) were detected. We found that compared with the C group, hemolysis rate, degree of polarization, and microviscosity of erythrocytes were increased in broilers of the ED group. The composition of erythrocyte membrane lipids was changed. Meanwhile, the antioxidant function of erythrocytes was weakened and mRNA levels of inflammatory genes were stimulated by Se deficiency (p < 0.05). In addition, mRNA expressions of rate-limiting enzymes in glycometabolism were effected and avUCP mRNA level was downregulated (p < 0.05) in the ED group. It has been concluded from the results that oxidative stress, inflammatory response, and glycometabolism disorder lead to erythrocyte hemolysis by changing the structure and function of erythrocyte membrane in ED broilers suffered from Se deficiency.
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Affiliation(s)
- Shufang Zheng
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People's Republic of China.,Key Laboratory of the Provincial Education, Department of Heilongjiang for Common Animal Disease Prevention and Treatment, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People's Republic of China
| | - Jinxin Zhao
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People's Republic of China
| | - Houjuan Xing
- Department of Animal Production, College of Animal Science and Technology, Northeast Agricultural University, Harbin, People's Republic of China
| | - Shiwen Xu
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People's Republic of China.,Key Laboratory of the Provincial Education, Department of Heilongjiang for Common Animal Disease Prevention and Treatment, College of Veterinary Medicine, Northeast Agricultural University, Harbin, People's Republic of China
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8
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Dias S, Paredes S, Ribeiro L. Drugs Involved in Dyslipidemia and Obesity Treatment: Focus on Adipose Tissue. Int J Endocrinol 2018; 2018:2637418. [PMID: 29593789 PMCID: PMC5822899 DOI: 10.1155/2018/2637418] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 09/28/2017] [Accepted: 10/11/2017] [Indexed: 12/15/2022] Open
Abstract
Metabolic syndrome can be defined as a state of disturbed metabolic homeostasis characterized by visceral obesity, atherogenic dyslipidemia, arterial hypertension, and insulin resistance. The growing prevalence of metabolic syndrome will certainly contribute to the burden of cardiovascular disease. Obesity and dyslipidemia are main features of metabolic syndrome, and both can present with adipose tissue dysfunction, involved in the pathogenic mechanisms underlying this syndrome. We revised the effects, and underlying mechanisms, of the current approved drugs for dyslipidemia and obesity (fibrates, statins, niacin, resins, ezetimibe, and orlistat; sibutramine; and diethylpropion, phentermine/topiramate, bupropion and naltrexone, and liraglutide) on adipose tissue. Specifically, we explored how these drugs can modulate the complex pathways involved in metabolism, inflammation, atherogenesis, insulin sensitivity, and adipogenesis. The clinical outcomes of adipose tissue modulation by these drugs, as well as differences of major importance for clinical practice between drugs of the same class, were identified. Whether solutions to these issues will be found in further adjustments and combinations between drugs already in use or necessarily in new advances in pharmacology is not known. To better understand the effect of drugs used in dyslipidemia and obesity on adipose tissue not only is challenging for physicians but could also be the next step to tackle cardiovascular disease.
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Affiliation(s)
- Sofia Dias
- Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Sílvia Paredes
- Department of Endocrinology, Hospital de Braga, 4710-243 Braga, Portugal
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Laura Ribeiro
- Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- I3S-Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal
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9
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Gupta A, Beg M, Kumar D, Shankar K, Varshney S, Rajan S, Srivastava A, Singh K, Sonkar S, Mahdi AA, Dikshit M, Gaikwad AN. Chronic hyper-leptinemia induces insulin signaling disruption in adipocytes: Implications of NOS2. Free Radic Biol Med 2017; 112:93-108. [PMID: 28739528 DOI: 10.1016/j.freeradbiomed.2017.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 07/11/2017] [Accepted: 07/20/2017] [Indexed: 01/12/2023]
Abstract
Leptin, following its discovery, has developed a formidable interest in the scientific community to delineate its contribution towards overall metabolic homeostasis. Contradictory reports have been published on leptin administration effects on whole body insulin sensitivity. Following late reports, we surveyed human serum leptin levels along with other metabolic parameters including BMI and HOMA-IR. We found a positive correlation between leptin levels and insulin resistance parameters. Considering the presence of the long form of leptin receptor on adipocytes, we explored the effects of chronic physiological hyper-leptinemic exposure on adipocyte insulin sensitivity. Chronic leptin (50ng/ml) treatment in 3T3-L1 adipocytes decreased insulin-induced phosphorylation of nodal insulin signaling proteins along with reduced glucose uptake. Metabolic flux studies indicated mitochondrial dysfunction and reduced oxygen consumption rate. Leptin treatment also increased both cellular and mitochondrial superoxide levels concomitant to increased expression of nitric oxide synthase-2 (NOS2). Further, pharmacological depletion of NOS2 reversed leptin mediated effects on insulin signaling. In-vivo implantation of leptin osmotic pumps in C57BL/6 mice also decreased insulin responsiveness. Interestingly, these effects were lacking in NOS2 knockout strain. In conclusion, our studies put forward a potential link between leptin and adipocyte insulin responsiveness in an NOS2 dependent manner.
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Affiliation(s)
- Abhishek Gupta
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Muheeb Beg
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Durgesh Kumar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Kripa Shankar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Salil Varshney
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Sujith Rajan
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Ankita Srivastava
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Kalpana Singh
- Department of Biochemistry, King George's Medical University, Lucknow 226003, India
| | - Satyendra Sonkar
- Department of Internal Medicine, King George's Medical University, Lucknow 226003, India
| | - Abbas Ali Mahdi
- Department of Biochemistry, King George's Medical University, Lucknow 226003, India
| | - Madhu Dikshit
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Anil Nilkanth Gaikwad
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India.
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10
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Pierelli G, Stanzione R, Forte M, Migliarino S, Perelli M, Volpe M, Rubattu S. Uncoupling Protein 2: A Key Player and a Potential Therapeutic Target in Vascular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7348372. [PMID: 29163755 PMCID: PMC5661070 DOI: 10.1155/2017/7348372] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 05/19/2017] [Accepted: 09/10/2017] [Indexed: 12/17/2022]
Abstract
Uncoupling protein 2 (UCP2) is an inner mitochondrial membrane protein that belongs to the uncoupling protein family and plays an important role in lowering mitochondrial membrane potential and dissipating metabolic energy with prevention of oxidative stress accumulation. In the present article, we will review the evidence that UCP2, as a consequence of its roles within the mitochondria, represents a critical player in the predisposition to vascular disease development in both animal models and in humans, particularly in relation to obesity, diabetes, and hypertension. The deletion of the UCP2 gene contributes to atherosclerosis lesion development in the knockout mice, also showing significantly shorter lifespan. The UCP2 gene downregulation is a key determinant of higher predisposition to renal and cerebrovascular damage in an animal model of spontaneous hypertension and stroke. In contrast, UCP2 overexpression improves both hyperglycemia- and high-salt diet-induced endothelial dysfunction and ameliorates hypertensive target organ damage in SHRSP. Moreover, drugs (fenofibrate and sitagliptin) and several vegetable compounds (extracts from Brassicaceae, berberine, curcumin, and capsaicin) are able to induce UCP2 expression level and to exert beneficial effects on the occurrence of vascular damage. As a consequence, UCP2 becomes an interesting therapeutic target for the treatment of common human vascular diseases.
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Affiliation(s)
- Giorgia Pierelli
- Department of Cardiovascular Disease, Tor Vergata University of Rome, Rome, Italy
| | | | | | - Serena Migliarino
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Marika Perelli
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Massimo Volpe
- IRCCS Neuromed, Pozzilli, Isernia, Italy
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
| | - Speranza Rubattu
- IRCCS Neuromed, Pozzilli, Isernia, Italy
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University of Rome, Rome, Italy
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11
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Jankovic A, Korac A, Buzadzic B, Stancic A, Otasevic V, Ferdinandy P, Daiber A, Korac B. Targeting the NO/superoxide ratio in adipose tissue: relevance to obesity and diabetes management. Br J Pharmacol 2017; 174:1570-1590. [PMID: 27079449 PMCID: PMC5446578 DOI: 10.1111/bph.13498] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/31/2016] [Accepted: 04/04/2016] [Indexed: 12/21/2022] Open
Abstract
Insulin sensitivity and metabolic homeostasis depend on the capacity of adipose tissue to take up and utilize excess glucose and fatty acids. The key aspects that determine the fuel-buffering capacity of adipose tissue depend on the physiological levels of the small redox molecule, nitric oxide (NO). In addition to impairment of NO synthesis, excessive formation of the superoxide anion (О2•- ) in adipose tissue may be an important interfering factor diverting the signalling of NO and other reactive oxygen and nitrogen species in obesity, resulting in metabolic dysfunction of adipose tissue over time. Besides its role in relief from superoxide burst, enhanced NO signalling may be responsible for the therapeutic benefits of different superoxide dismutase mimetics, in obesity and experimental diabetes models. This review summarizes the role of NO in adipose tissue and highlights the effects of NO/О2•- ratio 'teetering' as a promising pharmacological target in the metabolic syndrome. LINKED ARTICLES This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.
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Affiliation(s)
- Aleksandra Jankovic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”University of BelgradeBelgradeSerbia
| | - Aleksandra Korac
- Faculty of Biology, Center for Electron MicroscopyUniversity of BelgradeBelgradeSerbia
| | - Biljana Buzadzic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”University of BelgradeBelgradeSerbia
| | - Ana Stancic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”University of BelgradeBelgradeSerbia
| | - Vesna Otasevic
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”University of BelgradeBelgradeSerbia
| | - Péter Ferdinandy
- Department of Pharmacology and PharmacotherapySemmelweis UniversityBudapestHungary
- Pharmahungary GroupSzegedHungary
| | - Andreas Daiber
- Center for Cardiology ‐ Cardiology 1, Molecular CardiologyUniversity Medical CenterMainzGermany
| | - Bato Korac
- Department of Physiology, Institute for Biological Research “Sinisa Stankovic”University of BelgradeBelgradeSerbia
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12
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Thangavel R, Kempuraj D, Zaheer S, Raikwar S, Ahmed ME, Selvakumar GP, Iyer SS, Zaheer A. Glia Maturation Factor and Mitochondrial Uncoupling Proteins 2 and 4 Expression in the Temporal Cortex of Alzheimer's Disease Brain. Front Aging Neurosci 2017; 9:150. [PMID: 28572767 PMCID: PMC5435744 DOI: 10.3389/fnagi.2017.00150] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/03/2017] [Indexed: 11/13/2022] Open
Abstract
Alzheimer’s disease (AD) is characterized by the presence of neuropathological lesions containing amyloid plaques (APs) and neurofibrillary tangles (NFTs). AD is associated with mitochondrial dysfunctions, neuroinflammation and neurodegeneration in the brain. We have previously demonstrated enhanced expression of the proinflammatory protein glia maturation factor (GMF) in glial cells near APs and NFTs in the AD brains. Parahippocampal gyrus consisting of entorhinal and perirhinal subdivisions of temporal cortex is the first brain region affected during AD pathogenesis. Current paradigm implicates oxidative stress-mediated neuronal damage contributing to the early pathology in AD with mitochondrial membrane potential regulating reactive oxygen species (ROS) production. The inner mitochondrial membrane anion transporters called the uncoupling proteins (UCPs), function as regulators of cellular homeostasis by mitigating oxidative stress. In the present study, we have analyzed the expression of GMF and mitochondrial UCP2 and UCP4 in the parahippocampal gyrus of AD and non-AD brains by immunostaining techniques. APs were detected by thioflavin-S fluorescence staining or immunohistochemistry (IHC) with 6E10 antibody. Our current results suggest that upregulation of GMF expression is associated with down-regulation of UCP2 as well as UCP4 in the parahippocampal gyrus of AD brains as compared to non-AD brains. Further, GMF expression is associated with up-regulation of inducible nitric oxide synthase (iNOS), the enzyme that induces the production of nitric oxide (NO), as well as nuclear factor kB p65 (NF-κB p65) expression. Also, GMF appeared to localize to the mitochondria in AD brains. Based on our current observations, we propose that enhanced expression of GMF down-regulates mitochondrial UCP2 and UCP4 thereby exacerbating AD pathophysiology and this effect is potentially mediated by iNOS and NF-κB. Thus, GMF functions as an activator protein that interferes with the cytoprotective mechanisms in AD brains.
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Affiliation(s)
- Ramasamy Thangavel
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States.,Research Services, Harry S. Truman Memorial Veterans HospitalColumbia, MO, United States
| | - Duraisamy Kempuraj
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States.,Research Services, Harry S. Truman Memorial Veterans HospitalColumbia, MO, United States
| | - Smita Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States
| | - Sudhanshu Raikwar
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States
| | - Mohammad E Ahmed
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States
| | | | - Shankar S Iyer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States
| | - Asgar Zaheer
- Department of Neurology, Center for Translational Neuroscience, School of Medicine, University of MissouriColumbia, MO, United States.,Research Services, Harry S. Truman Memorial Veterans HospitalColumbia, MO, United States
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Kumazoe M, Nakamura Y, Yamashita M, Suzuki T, Takamatsu K, Huang Y, Bae J, Yamashita S, Murata M, Yamada S, Shinoda Y, Yamaguchi W, Toyoda Y, Tachibana H. Green Tea Polyphenol Epigallocatechin-3-gallate Suppresses Toll-like Receptor 4 Expression via Up-regulation of E3 Ubiquitin-protein Ligase RNF216. J Biol Chem 2017; 292:4077-4088. [PMID: 28154178 DOI: 10.1074/jbc.m116.755959] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/18/2017] [Indexed: 12/13/2022] Open
Abstract
Toll-like receptor 4 (TLR4) plays an essential role in innate immunity through inflammatory cytokine induction. Recent studies demonstrated that the abnormal activation of TLR4 has a pivotal role in obesity-induced inflammation, which is associated with several diseases, including hyperinsulinemia, hypertriglyceridemia, and cardiovascular disease. Here we demonstrate that (-)-epigallocatechin-3-O-gallate, a natural agonist of the 67-kDa laminin receptor (67LR), suppressed TLR4 expression through E3 ubiquitin-protein ring finger protein 216 (RNF216) up-regulation. Our data indicate cyclic GMP mediates 67LR agonist-dependent RNF216 up-regulation. Moreover, we show that the highly absorbent 67LR agonist (-)-epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3″Me) significantly attenuated TLR4 expression in the adipose tissue. EGCG3″Me completely inhibited the high-fat/high-sucrose (HF/HS)-induced up-regulation of tumor necrosis factor α in adipose tissue and serum monocyte chemoattractant protein-1 increase. Furthermore, this agonist intake prevented HF/HS-induced hyperinsulinemia and hypertriglyceridemia. Taken together, 67LR presents an attractive target for the relief of obesity-induced inflammation.
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Affiliation(s)
- Motofumi Kumazoe
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Yuki Nakamura
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Mai Yamashita
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Takashi Suzuki
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Kanako Takamatsu
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Yuhui Huang
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Jaehoon Bae
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Shuya Yamashita
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Motoki Murata
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Shuhei Yamada
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
| | - Yuki Shinoda
- the Products Research & Development Laboratory, Asahi Soft Drinks Co., Ltd., Ibaraki 302-0106, Japan
| | - Wataru Yamaguchi
- the Products Research & Development Laboratory, Asahi Soft Drinks Co., Ltd., Ibaraki 302-0106, Japan
| | - Yui Toyoda
- the Products Research & Development Laboratory, Asahi Soft Drinks Co., Ltd., Ibaraki 302-0106, Japan
| | - Hirofumi Tachibana
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 and
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Litvinova L, Atochin DN, Fattakhov N, Vasilenko M, Zatolokin P, Kirienkova E. Nitric oxide and mitochondria in metabolic syndrome. Front Physiol 2015; 6:20. [PMID: 25741283 PMCID: PMC4330700 DOI: 10.3389/fphys.2015.00020] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 01/12/2015] [Indexed: 12/15/2022] Open
Abstract
Metabolic syndrome (MS) is a cluster of metabolic disorders that collectively increase the risk of cardiovascular disease. Nitric oxide (NO) plays a crucial role in the pathogeneses of MS components and is involved in different mitochondrial signaling pathways that control respiration and apoptosis. The present review summarizes the recent information regarding the interrelations of mitochondria and NO in MS. Changes in the activities of different NO synthase isoforms lead to the formation of metabolic disorders and therefore are highlighted here. Reduced endothelial NOS activity and NO bioavailability, as the main factors underlying the endothelial dysfunction that occurs in MS, are discussed in this review in relation to mitochondrial dysfunction. We also focus on potential therapeutic strategies involving NO signaling pathways that can be used to treat patients with metabolic disorders associated with mitochondrial dysfunction. The article may help researchers develop new approaches for the diagnosis, prevention and treatment of MS.
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Affiliation(s)
- Larisa Litvinova
- Laboratory of Immunology and Cellular Biotechnologies, Innovation Park of the Immanuel Kant Baltic Federal UniversityKaliningrad, Russia
| | - Dmitriy N. Atochin
- Cardiology Division, Department of Medicine, Cardiovascular Research Center, Harvard Medical School, Massachusetts General HospitalBoston, MA, USA
| | - Nikolai Fattakhov
- Laboratory of Immunology and Cellular Biotechnologies, Innovation Park of the Immanuel Kant Baltic Federal UniversityKaliningrad, Russia
| | - Mariia Vasilenko
- Laboratory of Immunology and Cellular Biotechnologies, Innovation Park of the Immanuel Kant Baltic Federal UniversityKaliningrad, Russia
| | - Pavel Zatolokin
- Department of Reconstructive and Endoscopic Surgery, Kaliningrad Regional HospitalKaliningrad, Russia
| | - Elena Kirienkova
- Laboratory of Immunology and Cellular Biotechnologies, Innovation Park of the Immanuel Kant Baltic Federal UniversityKaliningrad, Russia
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15
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Sansbury BE, Hill BG. Regulation of obesity and insulin resistance by nitric oxide. Free Radic Biol Med 2014; 73:383-99. [PMID: 24878261 PMCID: PMC4112002 DOI: 10.1016/j.freeradbiomed.2014.05.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 02/07/2023]
Abstract
Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a worldwide pandemic with few tangible and safe treatment options. Although it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many "distal" causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity-those that directly regulate energy metabolism or caloric intake-seem to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin-resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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16
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Gómez-Hernández A, Perdomo L, de las Heras N, Beneit N, Escribano O, Otero YF, Guillén C, Díaz-Castroverde S, Gozalbo-López B, Cachofeiro V, Lahera V, Benito M. Antagonistic effect of TNF-alpha and insulin on uncoupling protein 2 (UCP-2) expression and vascular damage. Cardiovasc Diabetol 2014; 13:108. [PMID: 25077985 PMCID: PMC4149264 DOI: 10.1186/s12933-014-0108-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/27/2014] [Indexed: 12/11/2022] Open
Abstract
Background It has been reported that increased expression of UCP-2 in the vasculature may prevent the development of atherosclerosis in patients with increased production of reactive oxygen species, as in the diabetes, obesity or hypertension. Thus, a greater understanding in the modulation of UCP-2 could improve the atherosclerotic process. However, the effect of TNF-α or insulin modulating UCP-2 in the vascular wall is completely unknown. In this context, we propose to study new molecular mechanisms that help to explain whether the moderate hyperinsulinemia or lowering TNF-α levels might have a protective role against vascular damage mediated by UCP-2 expression levels. Methods We analyzed the effect of insulin or oleic acid in presence or not of TNF-α on UCP-2 expression in murine endothelial and vascular smooth muscle cells. At this step, we wondered if some mechanisms studied in vitro could be of any relevance in vivo. We used the following experimental models: ApoE−/− mice under Western type diet for 2, 6, 12 or 18 weeks, BATIRKO mice under high-fat diet for 16 weeks and 52-week-old BATIRKO mice with o without anti-TNF-α antibody pre-treatment. Results Firstly, we found that TNF-α pre-treatment reduced UCP-2 expression induced by insulin in vascular cells. Secondly, we observed a progressive reduction of UCP-2 levels together with an increase of lipid depots and lesion area in aorta from ApoE−/− mice. In vivo, we also observed that moderate hyperinsulinemic obese BATIRKO mice have lower TNF-α and ROS levels and increased UCP-2 expression levels within the aorta, lower lipid accumulation, vascular dysfunction and macrovascular damage. We also observed that the anti-TNF-α antibody pre-treatment impaired the loss of UCP-2 expression within the aorta and relieved vascular damage observed in 52-week-old BATIRKO mice. Finally, we observed that the pretreatment with iNOS inhibitor prevented UCP-2 reduction induced by TNF-α in vascular cells. Moreover, iNOS levels are augmented in aorta from mice with lower UCP-2 levels and higher TNF-α levels. Conclusions Our data suggest that moderate hyperinsulinemia in response to insulin resistance or lowering of TNF-α levels within the aorta attenuates vascular damage, this protective effect being mediated by UCP-2 expression levels through iNOS. Electronic supplementary material The online version of this article (doi:10.1186/s12933-014-0108-9) contains supplementary material, which is available to authorized users.
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Schiffer TA, Larsen FJ, Lundberg JO, Weitzberg E, Lindholm P. Effects of dietary inorganic nitrate on static and dynamic breath-holding in humans. Respir Physiol Neurobiol 2012; 185:339-48. [PMID: 23099220 DOI: 10.1016/j.resp.2012.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/17/2012] [Accepted: 09/18/2012] [Indexed: 10/27/2022]
Abstract
Inorganic nitrate has been shown to reduce oxygen cost during exercise. Since the nitrate-nitrite-NO pathway is facilitated during hypoxia, we investigated the effects of dietary nitrate on oxygen consumption and cardiovascular responses during apnea. These variables were measured in two randomized, double-blind, placebo-controlled, crossover protocols at rest and ergometer exercise in competitive breath-hold divers. Subjects held their breath for predetermined times along with maximum effort apneas after two separate 3-day periods with supplementation of potassium nitrate/placebo. In contrast to our hypothesis, nitrate supplementation led to lower arterial oxygen saturation (SaO(2), 77 ± 3%) compared to placebo (80 ± 2%) during static apnea, along with lower end-tidal fraction of oxygen (FETO(2)) after 4 min of apnea (nitrate 6.9 ± 0.4% vs. placebo 7.6 ± 0.4%). Maximum apnea duration was shorter after nitrate (329 ± 13 s) compared to placebo (344 ± 13 s). During cycle ergometry nitrate had no effect on SaO(2), FETO(2) or maximum apnea duration. The negative effects of inorganic nitrate during static apnea may be explained by an attenuated diving response.
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Affiliation(s)
- Tomas A Schiffer
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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18
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Abstract
Understanding the role of oxidative injury will allow for therapy with agents that scavenge ROS (reactive oxygen species) and antioxidants in the management of several diseases related to free radical damage. The majority of free radicals are generated by mitochondria as a consequence of the mitochondrial cycle, whereas free radical accumulation is limited by the action of a variety of antioxidant processes that reside in every cell. In the present review, we provide an overview of the mitochondrial generation of ROS and discuss the role of ROS in the regulation of endothelial and adipocyte function. Moreover, we also discuss recent findings on the role of ROS in sepsis, cerebral ataxia and stroke. These results provide avenues for the therapeutic potential of antioxidants in a variety of diseases.
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19
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Deletion of inducible nitric-oxide synthase in leptin-deficient mice improves brown adipose tissue function. PLoS One 2010; 5:e10962. [PMID: 20532036 PMCID: PMC2881035 DOI: 10.1371/journal.pone.0010962] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 05/16/2010] [Indexed: 01/22/2023] Open
Abstract
Background Leptin and nitric oxide (NO) on their own participate in the control of non-shivering thermogenesis. However, the functional interplay between both factors in this process has not been explored so far. Therefore, the aim of the present study was to analyze the impact of the absence of the inducible NO synthase (iNOS) gene in the regulation of energy balance in ob/ob mice. Methods and Findings Double knockout (DBKO) mice simultaneously lacking the ob and iNOS genes were generated, and the expression of molecules involved in the control of brown fat cell function was analyzed by real-time PCR, western-blot and immunohistochemistry. Twelve week-old DBKO mice exhibited reduced body weight (p<0.05), decreased amounts of total fat pads (p<0.05), lower food efficiency rates (p<0.05) and higher rectal temperature (p<0.05) than ob/ob mice. Ablation of iNOS also improved the carbohydrate and lipid metabolism of ob/ob mice. DBKO showed a marked reduction in the size of brown adipocytes compared to ob/ob mutants. In this sense, in comparison to ob/ob mice, DBKO rodents showed an increase in the expression of PR domain containing 16 (Prdm16), a transcriptional regulator of brown adipogenesis. Moreover, iNOS deletion enhanced the expression of mitochondria-related proteins, such as peroxisome proliferator-activated receptor γ coactivator-1 α (Pgc-1α), sirtuin-1 (Sirt-1) and sirtuin-3 (Sirt-3). Accordingly, mitochondrial uncoupling proteins 1 and 3 (Ucp-1 and Ucp-3) were upregulated in brown adipose tissue (BAT) of DBKO mice as compared to ob/ob rodents. Conclusion Ablation of iNOS improved the energy balance of ob/ob mice by decreasing food efficiency through an increase in thermogenesis. These effects may be mediated, in part, through the recovery of the BAT phenotype and brown fat cell function improvement.
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20
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Leung PS, Cheng Q. The Novel Roles of Glucagon-Like Peptide-1, Angiotensin II, and Vitamin D in Islet Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:339-61. [DOI: 10.1007/978-90-481-3271-3_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Lien CC, Au LC, Tsai YL, Ho LT, Juan CC. Short-term regulation of tumor necrosis factor-alpha-induced lipolysis in 3T3-L1 adipocytes is mediated through the inducible nitric oxide synthase/nitric oxide-dependent pathway. Endocrinology 2009; 150:4892-900. [PMID: 19819972 DOI: 10.1210/en.2009-0403] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TNF-alpha has several effects on adipocytes that may be related to the development of type 2 diabetes in obese subjects. Many studies demonstrated that long-term treatment with TNF-alpha increases lipolysis in adipocytes. However, the short-term (<4 h) effects of TNF-alpha on lipolysis have not been well investigated. The aim of this study was to investigate the short-term regulatory mechanism of TNF-alpha-induced lipolysis in 3T3-L1 adipocytes. Well-differentiated 3T3-L1 adipocytes were used. Lipolysis was determined by measuring glycerol release. Expression of inducible nitric oxide (iNOS) and nitric oxide (NO) production were measured, respectively, by Western blots and the Griess reagent. A selective iNOS inhibitor (s-ethylisothiourea . HBr), an adenylyl cyclase inhibitor (SQ22536), and a guanylyl cyclase inhibitor (LY83583) were used to investigate the involvement of iNOS, cAMP, and cGMP in TNF-alpha-induced lipolysis. Transient transfection with iNOS short hairpin RNA was performed to confirm the involvement of iNOS in TNF-alpha-induced lipolysis. Phosphorylation of hormone-sensitive lipase (HSL) was measured by immunoprecipitation and Western blotting. Results showed that short-term TNF-alpha treatment significantly increased lipolysis, iNOS expression, and NO production in a time- and dose-dependent manner. Furthermore, treatment with the NO donor S-nitroso-N-acetylpenicillamine also stimulated lipolysis and HSL phosphorylation in 3T3-L1 adipocytes. Moreover, pretreatment with inhibitors of iNOS and guanylate cyclase, but not an adenylate cyclase inhibitor, abolished TNF-alpha-induced lipolysis and HSL phosphorylation. Suppression of TNF-alpha-induced iNOS expression using short hairpin RNA significantly reduced TNF-alpha-induced lipolysis. In conclusion, short-term TNF-alpha treatment induces lipolysis in 3T3-L1 adipocytes by increasing iNOS expression and NO production, which activates the guanylyl cyclase/cGMP-dependent pathway and induces phosphorylation of HSL.
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Affiliation(s)
- Chih-Chan Lien
- Department of Physiology, National Yang-Ming University, Number 155, Section 2, Li-Nong Street, Taipei, Taiwan.
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Wu QL, Buhtoiarov IN, Sondel PM, Rakhmilevich AL, Ranheim EA. Tumoricidal effects of activated macrophages in a mouse model of chronic lymphocytic leukemia. THE JOURNAL OF IMMUNOLOGY 2009; 182:6771-8. [PMID: 19454672 DOI: 10.4049/jimmunol.0801847] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Emu-TCL1 transgenic mouse spontaneously develops a CD5(+) B cell lymphoproliferative disorder similar to human chronic lymphocytic leukemia (CLL). Given the ineffectual T cell antitumor responses in this mouse model of CLL, we sought to determine whether combined treatment with anti-CD40 mAb (alphaCD40) and CpG-containing oligodeoxynucleotides (CpG) could exert immunotherapeutic effects. We have previously shown that macrophages activated by sequential ligation of CD40 and TLR9 could become cytotoxic against solid tumor cell lines both in vitro and in vivo. In the current study, we find that alphaCD40 plus CpG-activated macrophages induce tumor B cell apoptosis in vitro and that alphaCD40 plus CpG treatment markedly retards tumor growth in immunodeficient SCID/Beige mice following transplantation of primary tumor B cells. Our results suggest a novel immunotherapeutic strategy for CLL that may be effective even in the face of tumor or chemotherapy-induced T cell immunodeficiency.
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Affiliation(s)
- Qing-Li Wu
- Department of Pathology and Laboratory Medicine, Pediatrics University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
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Cheng Q, Law PK, de Gasparo M, Leung PS. Combination of the dipeptidyl peptidase IV inhibitor LAF237 [(S)-1-[(3-hydroxy-1-adamantyl)ammo]acetyl-2-cyanopyrrolidine] with the angiotensin II type 1 receptor antagonist valsartan [N-(1-oxopentyl)-N-[[2'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-4-yl]methyl]-L-valine] enhances pancreatic islet morphology and function in a mouse model of type 2 diabetes. J Pharmacol Exp Ther 2008; 327:683-91. [PMID: 18787107 DOI: 10.1124/jpet.108.142703] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
LAF237 [(S)-1-[(3-hydroxy-1-adamantyl)ammo]acetyl-2-cyanopyrrolidine] is an inhibitor of dipeptidyl peptidase IV that delays the degradation of glucagon-like peptide-1 (GLP-1). Valsartan [N-(1-oxopentyl)-N-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-l-valine] is an antagonist of the angiotensin II type 1 receptor (AT1R) that reduces the incidence of type 2 diabetes mellitus. LAF237 and valsartan act on a common target through separate pathways to improve pancreatic islet cell function. We hypothesize that the combination of these two drugs acts in a synergistic or additive manner on islet function and structure. To test this hypothesis, we performed in vitro and in vivo studies. To measure the acute effect of the treatment, pancreatic islets of db/db mice were isolated and stimulated in vitro with glucose in the presence of valsartan (1 microM) and exendin-4 (100 nM), a GLP-1 receptor agonist. Combination treatment with valsartan and exendin-4 significantly enhanced glucose-stimulated insulin secretion from isolated islets. For studies of chronic effect, db/db mice received LAF237 (1 mg/kg/day) and/or valsartan (10 mg/kg/day). Islet cell reactive oxygen species (ROS), proliferation, apoptosis, fibrosis, beta-cell area, and glucose homeostasis were evaluated after 8 weeks of treatment, which showed that combination treatment resulted in a significant increase in pancreatic islet beta-cell area compared with monotherapy. This beneficial effect correlated with an increase in beta-cell proliferation and a decrease in ROS-induced islet apoptosis and fibrosis. These in vitro and in vivo data indicate that combination treatment with LAF237 and valsartan has significant beneficial additive effects on pancreatic beta-cell structure and function compared with their respective monotherapeutic effects.
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Affiliation(s)
- Qianni Cheng
- Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Kung LC, Chan SHH, Wu KLH, Ou CC, Tai MH, Chan JYH. Mitochondrial respiratory enzyme complexes in rostral ventrolateral medulla as cellular targets of nitric oxide and superoxide interaction in the antagonism of antihypertensive action of eNOS transgene. Mol Pharmacol 2008; 74:1319-32. [PMID: 18715945 DOI: 10.1124/mol.108.048793] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Overproduction of nitric oxide (NO) by gene transduction of endothelial NO synthase (eNOS) in rostral ventrolateral medulla (RVLM), which is responsible for maintenance of vasomotor tone, reduces arterial pressure in spontaneously hypertensive rats (SHR). This NO-induced vasodepression, however, is not sustained and is followed by rebound hypertension. Because superoxide anion (O(2)(*-)) level is increased and synthesis or activity of mitochondrial manganese superoxide dismutase (SOD2) is reduced in RVLM during hypertension, we hypothesized that an interaction between NO and O(2)(*-) in RVLM, using mitochondrial respiratory enzyme complexes (MRC) as the cellular target, contributes to those cardiovascular outcomes after eNOS gene transduction in SHR. The present study assessed this hypothesis using adenoviral vectors to overexpress eNOS (AdeNOS) and/or SOD2 (AdSOD2) in RVLM of SHR or normotensive Wistar-Kyoto (WKY) rats. Microinjection of AdeNOS bilaterally into RVLM elicited 35% depression of MRC-I enzyme activity and evoked 60% and 50% increase in O(2)(*-) and peroxynitrite level in RVLM of SHR, but not WKY rats, which was reversed by cotransduced AdSOD2 or treatment with peroxynitrite decomposition catalyst. Cotransduction of AdeNOS and AdSOD2 in RVLM of SHR elicited significantly greater decreases in arterial pressure and heart rate than those promoted by the individual transgene and prevented the AdeNOS-induced rebound hypertension. We conclude that an interactive action between NO and O(2)(*-) on MRC-I in RVLM via formation of peroxynitrite contributes to the unsustained hypotensive effects of NO after overexpression of eNOS in SHR. The mitochondria-derived O(2)(*-) also mediates the rebound hypertension induced by eNOS transgene in RVLM of SHR.
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Affiliation(s)
- Ling-Chang Kung
- Department of Neurology, Antai Tian-Sheng Memorial Hospital, Pintong, Taiwan, Republic of China
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25
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Juan CC, Lien CC, Chang CL, Huang YH, Ho LT. Involvement of iNOS and NO in TNF-alpha-downregulated resistin gene expression in 3T3-L1 adipocytes. Obesity (Silver Spring) 2008; 16:1219-25. [PMID: 18369347 DOI: 10.1038/oby.2008.200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE In order to characterize the regulation of resistin gene expression, we explore the effect of tumornecrosis factor-alpha (TNF-alpha) on resistin mRNA expression and its underlying mechanism in 3T3-L1 adipocytes. METHODS AND PROCEDURES Differentiated 3T3-L1 adipocytes were treated for 24 h with 0-10 ng/ml of TNF-alpha or with 2.5 ng/ml of TNF-alpha for 0-24 h, and then resistin mRNA levels were measured by northern blotting. To further explore the involvement of nitric oxide (NO) in TNF-alpha-regulated resistin expression, the effect of the NO donor, sodium nitroprusside (SNP), on resistin mRNA levels in adipocytes and the effect of the nitric oxide synthase (NOS) inhibitors, N(G)-nitro-L-arginine methyl ester (L-NAME), and S,S'-1,3-phenylene-bis(1,2-ethanediyl)-bis-isothiourea.2HBr (PBITU), on the TNF-alpha effect in adipocytes were examined. The effects of TNF-alpha on inducible NOS (iNOS) protein expression in adipocytes were also measured by western blotting. RESULTS Our results showed that TNF-alpha caused a dose-dependent reduction in resistin mRNA levels. This effect seemed to be associated with the TNF-alpha-induced expression of iNOS. The results showed that TNF-alpha induced iNOS expression and release of NO after 24-h treatment of differentiated 3T3-L1 adipocytes. Pretreatment with L-NAME and PBITU significantly reversed the TNF-alpha-induced downregulation of resistin expression, while treatment with SNP mimicked the inhibitory effect of TNF-alpha on resistin expression. In addition, pretreatment with protein tyrosine kinase (PTK) inhibitors, genistein and AG-1288, prevented TNF-alpha-induced iNOS expression and subsequent resistin downregulation. DISCUSSION Our data suggest that TNF-alpha suppresses resistin expression by inducing iNOS expression, thus causing overproduction of NO, which downregulates resistin gene expression.
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Affiliation(s)
- Chi-Chang Juan
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
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Juan CC, Chang CL, Chuang TY, Huang SW, Kwok CF, Ho LT. Insulin sensitivity and resistin expression in nitric oxide-deficient rats. Diabetologia 2006; 49:3017-26. [PMID: 17063326 DOI: 10.1007/s00125-006-0403-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 07/03/2006] [Indexed: 12/30/2022]
Abstract
AIMS/HYPOTHESIS The aim of this study was to investigate changes in insulin sensitivity and expression of the gene encoding resistin (Retn) in adipocytes from long-term nitric oxide (NO)-deficient rats. METHODS Male Sprague-Dawley rats received [Formula: see text]-nitro-L: -arginine methyl ester (L-NAME 0.5 mg/ml) in their drinking water for 4 weeks, while control rats received plain drinking water. During the experimental period, changes in plasma glucose, insulin and C-peptide levels were measured. After administration of L-NAME for 4 weeks, insulin sensitivity was evaluated in vivo and in vitro. An insulin binding assay was also performed to determine the number and binding affinity of insulin receptors in adipocytes. Adipocyte Retn mRNA levels were examined using northern blotting. RESULTS Successful induction of NO deficiency was demonstrated by an increase in systemic blood pressure. No difference in plasma glucose levels was found between the two groups. Compared with the control rats, plasma insulin and C-peptide levels were significantly decreased in the NO-deficient rats, and insulin sensitivity was significantly increased. Insulin-stimulated glucose uptake and insulin binding capacity, but not binding affinity, were significantly increased in adipocytes isolated from NO-deficient rats. In addition, adipocyte Retn mRNA levels, but not plasma resistin levels, were significantly decreased in NO-deficient rats, and the Retn mRNA levels were negatively correlated with insulin sensitivity. CONCLUSIONS/INTERPRETATION Insulin sensitivity was increased in NO-deficient rats and this was associated with insulin binding capacity and downregulated Retn expression. These findings suggest that NO plays a regulatory role in metabolism. Dysregulation of NO production may result in the development of metabolic disorders.
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Affiliation(s)
- C C Juan
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
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27
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Carpéné C, Daviaud D, Boucher J, Bour S, Visentin V, Grès S, Duffaut C, Fontana E, Testar X, Saulnier-Blache JS, Valet P. Short- and long-term insulin-like effects of monoamine oxidases and semicarbazide-sensitive amine oxidase substrates in cultured adipocytes. Metabolism 2006; 55:1397-405. [PMID: 16979412 DOI: 10.1016/j.metabol.2006.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 06/16/2006] [Indexed: 01/12/2023]
Abstract
Semicarbazide-sensitive amine oxidase (SSAO) is known to increase during in vitro adipogenesis and to be one of the most highly expressed membrane proteins of white adipocytes. Although less well documented, mitochondrial monoamine oxidases (MAOs) are also present in adipocytes and share with SSAO the capacity to generate hydrogen peroxide. This work therefore aimed to compare several biologic effects of MAO and SSAO substrates in 3T3-F442A adipocytes. In differentiated cells, tyramine oxidation was predominantly MAO dependent, whereas benzylamine oxidation was SSAO dependent. Both amines partially mimicked insulin actions, including stimulation of Akt phosphorylation and glucose uptake. In addition, tyramine and benzylamine impaired tumor necrosis factor alpha-dependent nitric oxide formation in a pargyline- and semicarbazide-sensitive manner, respectively. Various biogenic amines were tested in competition for tyramine or benzylamine oxidation and classified as MAO-preferring (methoxytyramine, tryptamine) or SSAO-preferring substrates (methylamine, octopamine). Short-term incubation with 1 mmol/L of all amines except histamine stimulated glucose uptake up to 20% to 50% of maximal insulin activation. One-week treatment with either MAO or SSAO substrates alone allowed postconfluent cells to differentiate into adipocytes, reproducing 60% of insulin-promoted lipid accumulation. All amines also exerted a slight improvement in the adipogenic action of insulin. Therefore, like SSAO, substrate activation of MAO can interact with adipocyte metabolism by mimicking diverse effects of insulin in addition to preventing tumor necrosis factor alpha-dependent responses.
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Affiliation(s)
- Christian Carpéné
- Institut National de la Santé et de la Recherche Médicale, U586 INSERM, IFR 31, CHU Rangueil, 31432 Toulouse cedex 4, France.
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28
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Unno Y, Akuta T, Sakamoto YI, Horiuchi S, Akaike T. Nitric oxide-induced downregulation of leptin production by 3T3-L1 adipocytes. Nitric Oxide 2006; 15:125-32. [PMID: 16442319 DOI: 10.1016/j.niox.2005.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2005] [Revised: 11/21/2005] [Accepted: 12/10/2005] [Indexed: 02/06/2023]
Abstract
Leptin secreted mainly by adipocytes plays an important role in insulin sensitivity in metabolic syndrome. Inducible nitric oxide synthase (iNOS) in 3T3-L1 adipocytes is induced by lipopolysaccharide (LPS) and several proinflammatory cytokines such as tumor necrosis factor-alpha and interferon-gamma (IFN-gamma). Because the role of iNOS-derived nitric oxide (NO) in adipocyte function has not been fully clarified, the question that we addressed in the present study was whether iNOS-derived NO is involved in regulation of leptin secretion by adipocytes. Incubation of 3T3-L1 adipocytes for 12h with a mixture of IFN-gamma and LPS caused not only a 55% reduction in leptin secretion and a 52% reduction in leptin mRNA, but also significant induction of iNOS at both protein and mRNA levels. Inhibition of leptin secretion that had been induced by the IFN-gamma-LPS mixture was completely nullified by NOS inhibitors such as Nomega-monomethyl-L-arginine and aminoguanidine. Treatment of adipocytes with NO donors such as an NONOate and S-nitrosoglutathione produced an effect on leptin secretion similar to that of the IFN-gamma-LPS mixture. It is likely therefore that NO mediates downregulation of leptin caused by the IFN-gamma-LPS mixture in 3T3-L1 adipocytes, which suggests an important role for NO in adipocyte functions.
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Affiliation(s)
- Yuka Unno
- Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
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McMullen MR, Pritchard MT, Wang Q, Millward CA, Croniger CM, Nagy LE. Early growth response-1 transcription factor is essential for ethanol-induced fatty liver injury in mice. Gastroenterology 2005; 128:2066-76. [PMID: 15940638 PMCID: PMC1959407 DOI: 10.1053/j.gastro.2005.02.065] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Early growth response-1 (Egr-1), an immediate early gene/zinc-finger transcription factor, is required for maximal stimulation of tumor necrosis factor alpha (TNF-alpha) transcription in response to lipopolysaccharide (LPS). Because chronic ethanol exposure sensitizes macrophages to LPS-stimulated TNF-alpha expression, we have investigated the role of Egr-1 in mediating increased LPS-stimulated TNF-alpha expression after chronic ethanol feeding. Furthermore, because TNF-alpha contributes to alcoholic liver injury, we tested the hypothesis that Egr-1 is required for the development of ethanol-induced fatty liver injury in wild type and egr-1 -/- mice. METHODS Wild-type and egr-1 -/- mice were fed ethanol-containing diets or pair-fed control diets for 6 weeks. RESULTS Wild-type mice fed the ethanol diet developed hepatic steatosis characterized by micro- and macrovesicular lipid accumulation. However, egr-1 -/- mice did not develop steatosis after ethanol feeding. Alanine transferase and TNF-alpha concentrations in serum were increased after ethanol feeding in wild-type but not egr-1 -/- mice. In wild-type mice, challenge with LPS increased Egr-1 messenger RNA (mRNA) and DNA binding activity in liver; this response to LPS was enhanced after chronic ethanol feeding. LPS challenge also increased hepatic TNF-alpha mRNA and serum TNF-alpha to a greater extent after ethanol feeding compared with pair-fed wild-type mice. However, chronic ethanol feeding did not enhance LPS-stimulated TNF-alpha mRNA or serum TNF-alpha in egr-1 -/- mice. CONCLUSIONS These data show that Egr-1 contributes to increased LPS-mediated TNF-alpha expression after chronic ethanol and that the absence of Egr-1 prevents chronic ethanol-induced fatty liver, as well as increased sensitivity to LPS.
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Affiliation(s)
- Megan R McMullen
- Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106-4906, USA
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30
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Gómez-Ambrosi J, Becerril S, Oroz P, Zabalza S, Rodríguez A, Muruzábal FJ, Archanco M, Gil MJ, Burrell MA, Frühbeck G. Reduced adipose tissue mass and hypoleptinemia in iNOS deficient mice: effect of LPS on plasma leptin and adiponectin concentrations. FEBS Lett 2004; 577:351-6. [PMID: 15556608 DOI: 10.1016/j.febslet.2004.10.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2004] [Revised: 10/05/2004] [Accepted: 10/08/2004] [Indexed: 11/29/2022]
Abstract
The aim of this study was to evaluate the impact of the lack of inducible NO synthase (iNOS) on body weight and adipose tissue mass as well as on plasma leptin and adiponectin in basal conditions and 6 h after lipopolysaccharide (LPS) administration in mice. Body weight was not different among male, six-week-old wild-type (WT) and iNOS-/- animals. However, the amount of epididymal white adipose tissue (EWAT) in iNOS-/- mice was significantly reduced (P<0.05). Circulating leptin and leptin mRNA in EWAT were decreased in iNOS-/- mice (P<0.05 and P<0.01, respectively). Plasma adiponectin and adiponectin mRNA were unchanged. LPS administration increased plasma leptin in both genotypes (P<0.05). Neither genotype nor treatment changed plasma adiponectin. In summary, iNOS-/- mice exhibited normal body weight but reduced adipose mass accompanied by hypoleptinemia. Leptin responsiveness to LPS in iNOS-/- mutants is preserved, showing that the LPS-induced rise in leptin is independent of the presence of functional iNOS. In addition, iNOS deficiency or LPS does not influence expression and circulating levels of adiponectin.
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Affiliation(s)
- Javier Gómez-Ambrosi
- Metabolic Research Laboratory, Clínica Universitaria de Navarra, Edificio CIFA, University of Navarra, Irunlarrea 1, 31008 Pamplona, Spain.
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Li LX, Yoshikawa H, Egeberg KW, Grill V. Interleukin-1beta swiftly down-regulates UCP-2 mRNA in beta-cells by mechanisms not directly coupled to toxicity. Cytokine 2003; 23:101-7. [PMID: 12967645 DOI: 10.1016/s1043-4666(03)00204-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Regulation of uncoupling protein-2 (UCP-2) in beta-cells is presently unclear but may involve oxidative stress. We tested for regulation by beta-cell toxic cytokines. Exposure to interleukin-1beta (IL-1beta, 10 ng/ml) for 6 h down-regulated UCP-2 mRNA in clonal INS-1 cells, by 37 +/- 7%, and in rat pancreatic islets, by 55 +/- 8%. In contrast, a 6 h exposure to IL-1beta did not affect viability as assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, or mitochondrial membrane potential, or ATP cellular contents. Continued exposure to IL-1beta was accompanied by decreased viability and persisting down-regulation of UCP-2 mRNA. Exposure to a combination of IL-1beta and tumor necrosis factor (TNF)-alpha for 48 h additively decreased cell viability and UCP-2 mRNA. The constitutive nitric oxide (NO) synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME, 1 mM) partially protected against toxicity but failed to significantly affect UCP-2 mRNA expression. The inducible NO synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA, 1 mM) protected completely against cytokine-induced toxicity. L-NMMA per se down-regulated UCP-2 mRNA (by 64 +/- 7%). Transfection with a UCP-2-antisense nucleotide failed to affect IL-1beta induced toxicity. In conclusion, down-regulation of UCP-2 mRNA by IL-1beta is an early event of cytokine interaction with beta-cells which is not directly coupled to toxicity.
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Affiliation(s)
- Li-Xin Li
- Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, N-7489 Trondheim, Norway
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Mérial-Kieny C, Lonchampt M, Cogé F, Verwaerde P, Galizzi JP, Boutin JA, Lafontan M, Levens N, Galitzky J, Félétou M. Endothelin-1 inhibits TNF alpha-induced iNOS expression in 3T3-F442A adipocytes. Br J Pharmacol 2003; 139:935-44. [PMID: 12839867 PMCID: PMC1573919 DOI: 10.1038/sj.bjp.0705325] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2003] [Revised: 04/01/2003] [Accepted: 04/10/2003] [Indexed: 01/25/2023] Open
Abstract
1. Endothelin-1 (ET-1) and tumor necrosis factor alpha (TNFalpha) by their action on adipocytes have been independently linked to the pathogenesis of insulino-resistance. In isolated adipocytes, TNFalpha induces the expression of the inducible nitric oxide synthase (iNOS). The purpose of the present work was, in the 3T3-F442A adipocyte cell line, to characterise TNFalpha-induced iNOS expression and to determine whether or not ET-1 could influence TNFalpha-induced iNOS expression and NO production. 2. In differentiated 3T3-F442A, treatment with TNFalpha (20 ng ml(-1)) induced the expression of a functional iNOS as demonstrated by nitrite assay, Western blot, reverse transcription-polymerase chain reaction and Northern blot analysis. TNFalpha-induced iNOS expression requires nuclear factor kappaB activation, but does not necessitate the activation of the PI-3 kinase/Akt and P38-MAP kinase pathways. 3. ET-1, but not ET-3, inhibited the TNFalpha-induced expression of iNOS protein and mRNA as well as nitrite production. The effects of ET-1 were blocked by a specific ETA (BQ123, pA(2) 7.4) but not by a specific ETB receptor antagonist (BQ788). 3T3-F442A adipocytes express the mRNAs for prepro-ET-1 and the ET-A receptor subtype, but not for the ET-B subtype. 4. The inhibitory effect of ET-1 was not affected by bisindolylmaleimide, SB 203580 or indomethacin, inhibitors of protein kinase C, p38-MAP kinase and cyclooxygenase, respectively, and was not associated with cAMP production. However, the effect of ET-1 was partially reversed by wortmannin, suggesting the involvement of PI3 kinase in the transduction signal of ET-1. 5. Differentiated 3T3-F442A adipocytes did not release ET-1 with or without exposure to TNFalpha, although the mRNA for preproET-1 was detected in both pre- and differentiated adipocytes. 6. Thus, these results confirm that adipocytes are a target for circulating ET-1 and demonstrate that the activation of the ETA receptor subtype can prevent TNFalpha-induced iNOS expression.
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Affiliation(s)
- Christelle Mérial-Kieny
- Département Diabète et Maladies Métaboliques, Institut de Recherche SERVIER, Suresnes 92150, France
- INSERM U317, Laboratoire de Pharmacologie Médicale et Clinique, Toulouse, France
| | - Michel Lonchampt
- Département Diabète et Maladies Métaboliques, Institut de Recherche SERVIER, Suresnes 92150, France
| | - Francis Cogé
- Département de Pharmacologie Cellulaire et Moléculaire, Institut de Recherche SERVIER, Croissy, France
| | - Patrick Verwaerde
- INSERM U317, Laboratoire de Pharmacologie Médicale et Clinique, Toulouse, France
| | - Jean-Pierre Galizzi
- Département de Pharmacologie Cellulaire et Moléculaire, Institut de Recherche SERVIER, Croissy, France
| | - Jean A Boutin
- Département de Pharmacologie Cellulaire et Moléculaire, Institut de Recherche SERVIER, Croissy, France
| | - Max Lafontan
- INSERM U317, Laboratoire de Pharmacologie Médicale et Clinique, Toulouse, France
| | - Nigel Levens
- Département Diabète et Maladies Métaboliques, Institut de Recherche SERVIER, Suresnes 92150, France
| | - Jean Galitzky
- INSERM U317, Laboratoire de Pharmacologie Médicale et Clinique, Toulouse, France
| | - Michel Félétou
- Département Diabète et Maladies Métaboliques, Institut de Recherche SERVIER, Suresnes 92150, France
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Brookes PS, Levonen AL, Shiva S, Sarti P, Darley-Usmar VM. Mitochondria: regulators of signal transduction by reactive oxygen and nitrogen species. Free Radic Biol Med 2002; 33:755-64. [PMID: 12208364 DOI: 10.1016/s0891-5849(02)00901-2] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The functional role of mitochondria in cell physiology has previously centered around metabolism, with oxidative phosphorylation playing a pivotal role. Recently, however, this perspective has changed significantly with the realization that mitochondria are active participants in signal transduction pathways, not simply the passive recipients of injunctions from the rest of the cell. In this review the emerging role of the mitochondrion in cell signaling is discussed in the context of cytochrome c release, hydrogen peroxide formation from the respiratory chain, and the nitric oxide-cytochrome c oxidase signaling pathway.
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Affiliation(s)
- Paul S Brookes
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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