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Yen IW, Chen SC, Lin CH, Fan KC, Yang CY, Hsu CY, Kuo CH, Lin MS, Lyu YP, Juan HC, Heng-Huei L, Li HY. Precision medicine in diabetes prediction: Exploring a subgroup-specific biomarker strategy for risk stratification. J Diabetes Investig 2025; 16:43-50. [PMID: 39535373 DOI: 10.1111/jdi.14311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2024] [Revised: 08/17/2024] [Accepted: 08/23/2024] [Indexed: 11/16/2024] Open
Abstract
INTRODUCTION The early detection of high-risk individuals is crucial to delay and reduce the incidence of type 2 diabetes. In this study, we aimed to explore the performance of a novel subgroup-specific biomarker strategy in the prediction of incident diabetes. MATERIALS AND METHODS In the Taiwan Lifestyle Cohort Study, adult subjects without diabetes were included and followed for the incidence of diabetes in 2006-2019. The biomarkers measured included blood secretogranin III (SCG3), vascular adhesion protein-1 (VAP-1), fibrinogen-like protein 1 (FGL1), angiopoietin-like protein 6 (ANGPTL6), and angiopoietin-like protein 4 (ANGPTL4). RESULTS Among the 1,287 subjects, 12.2% developed diabetes during a 6 year follow-up. Blood VAP-1 was significantly associated with incident diabetes in the overall population (HR = 0.724, P < 0.05), participants under 65 years old (HR = 0.685, P < 0.05), those with a BMI of ≥24 kg/m2 (HR = 0.673, P < 0.05), and females (HR = 0.635, P < 0.05). Blood ANGPTL6 was significantly correlated with incident diabetes in participants aged 65 and older (HR = 0.314, P < 0.05), and blood SCG3 was associated with incident diabetes in those with a BMI of <24 kg/m2 (HR = 1.296, P < 0.05). Two subgroup-specific biomarker strategies were developed. The gender and BMI-specific biomarker strategy, using traditional risk factors and blood SCG3 or VAP-1 in different subgroups, could improve prediction performance, especially the specificity and positive prediction value, compared with the whole-population strategy using only traditional risk factors or traditional risk factors plus blood VAP-1. CONCLUSION Gender- and BMI-specific biomarker strategy can improve the prediction of incident diabetes. A subgroup-specific biomarker strategy is a novel approach in the prediction of incident diabetes.
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Affiliation(s)
- I-Weng Yen
- Department of Internal Medicine, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu County, Taiwan
- College of Medicine, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
| | - Szu-Chi Chen
- Department of Internal Medicine, Taipei City Hospital, Ren-Ai Branch, Taipei, Taiwan
| | - Chia-Hung Lin
- Division of Endocrinology and Metabolism, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Kang-Chih Fan
- Department of Internal Medicine, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu County, Taiwan
- College of Medicine, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
| | - Chung-Yi Yang
- School of Medicine, College of Medicine, I-Shou University, Kaohsiung, Taiwan
- Department of Medical Imaging, E-DA Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Chih-Yao Hsu
- Department of Internal Medicine, Taipei City Hospital, Ren-Ai Branch, Taipei, Taiwan
| | - Chun-Heng Kuo
- College of Medicine, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Mao-Shin Lin
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ya-Pin Lyu
- Department of Obstetrics & Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsien-Chia Juan
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Lin Heng-Huei
- Department of Obstetrics & Gynecology, National Taiwan University Hospital, Taipei, Taiwan
| | - Hung-Yuan Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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Yen I, Li H. The role of vascular adhesion protein-1 in diabetes and diabetic complications. J Diabetes Investig 2024; 15:982-989. [PMID: 38581224 PMCID: PMC11292389 DOI: 10.1111/jdi.14209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 03/21/2024] [Indexed: 04/08/2024] Open
Abstract
Vascular adhesion protein-1 (VAP-1) plays a dual role with its adhesive and enzymatic properties, facilitating leukocyte migration to sites of inflammation and catalyzing the breakdown of primary amines into harmful by-products, which are linked to diabetic complications. Present in various tissues, VAP-1 also circulates in a soluble form in the bloodstream. Diabetes is associated with several complications such as cardiovascular disease, retinopathy, nephropathy, and neuropathy, significantly contributing to disability and mortality. These complications arise from hyperglycemia-induced oxidative stress, inflammation, and the formation of advanced glycation end-products (AGEs). Earlier research, including our own from the 1990s and early 2000s, has underscored the critical role of VAP-1 in these pathological processes, prompting extensive investigation into its contribution to diabetic complications. In this review, we examine the involvement of VAP-1 in diabetes and its complications, alongside its link to other conditions related to diabetes, such as cancer and metabolic dysfunction-associated fatty liver disease. We also explore the utility of soluble VAP-1 as a biomarker for diabetes, its complications, and other related conditions. Since the inhibition of VAP-1 to treat diabetic complications is a novel and promising treatment option, further studies are needed to translate the beneficial effect of VAP-1 inhibitors observed in animal studies to clinical trials recruiting human subjects. Besides, future studies should focus on using serum sVAP-1 levels for risk assessment in diabetic patients, identifying those who need intensive glycemic control, and determining the patient population that would benefit most from VAP-1 inhibitor therapies.
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Affiliation(s)
- I‐Weng Yen
- Division of Endocrinology and Metabolism, Department of Internal MedicineNational Taiwan University Hospital Hsin‐Chu BranchHsinchuTaiwan
| | - Hung‐Yuan Li
- Division of Endocrinology and Metabolism, Department of Internal MedicineNational Taiwan University HospitalTaipeiTaiwan
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Semicarbazide-Sensitive Amine Oxidase (SSAO) and Lysyl Oxidase (LOX) Association in Rat Aortic Vascular Smooth Muscle Cells. Biomolecules 2022; 12:biom12111563. [DOI: 10.3390/biom12111563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022] Open
Abstract
Vascular smooth muscle cells (VSMCs) are the main stromal cells in the medial layer of the vascular wall. These cells produce the extracellular matrix (ECM) and are involved in many pathological changes in the vascular wall. Semicarbazide-sensitive amine oxidase (SSAO) and lysyl oxidase (LOX) are vascular enzymes associated with the development of atherosclerosis. In the vascular smooth muscle cells, increased SSAO activity elevates reactive oxygen species (ROS) and induces VSMCs death; increased LOX induces chemotaxis through hydrogen peroxide dependent mechanisms; and decreased LOX contributes to endothelial dysfunction. This study investigates the relationship between SSAO and LOX in VSMCs by studying their activity, protein, and mRNA levels during VSMCs passaging and after silencing the LOX gene, while using their respective substrates and inhibitors. At the basal level, LOX activity decreased with passage and its protein expression was maintained between passages. βAPN abolished LOX activity (** p < 0.01 for 8 vs. 3 and * p < 0.05 for 5 vs. 8) and had no effect on LOX protein and mRNA levels. MDL72527 reduced LOX activity at passage 3 and 5 (## p < 0.01) and had no effect on LOX protein, and mRNA expression. At the basal level, SSAO activity also decreased with passage, and its protein expression was maintained between passages. MDL72527 abolished SSAO activity (**** p < 0.0001 for 8 vs. 3 and * p < 0.05 for 5 vs. 8), VAP-1 expression at passage 5 (** p < 0.01) and 8 (**** p < 0.0001), and Aoc3 mRNA levels at passage 8 (* p < 0.05). βAPN inhibited SSAO activity (**** p < 0.0001 for 5 vs. 3 and 8 vs. 3 and * p < 0.05 for 5 vs. 8), VAP-1 expression at passage 3 (* p < 0.05), and Aoc3 mRNA levels at passage 3 (* p < 0.05). Knockdown of the LOX gene (**** p < 0.0001 for Si6 vs. Sictrl and *** p < 0.001 for Si8 vs. Sictrl) and LOX protein (** p < 0.01 for Si6 and Si8 vs. Sictrl) in VSMCs at passage 3 resulted in a reduction in Aoc3 mRNA (#### p < 0.0001 for Si6 vs. Sictrl and ### p < 0.001 for Si8 vs. Sictrl) and VAP-1 protein (# p < 0.05 for Si8 vs. Sictrl). These novel findings demonstrate a passage dependent decrease in LOX activity and increase in SSAO activity in rat aortic VSMCs and show an association between both enzymes in early passage rat aortic VSMCs, where LOX was identified as a regulator of SSAO activity, protein, and mRNA expression.
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Carpéné C, Viana P, Iffiú-Soltesz Z, Tapolcsányi P, Földi AÁ, Mátyus P, Dunkel P. Effects of Chemical Structures Interacting with Amine Oxidases on Glucose, Lipid and Hydrogen Peroxide Handling by Human Adipocytes. Molecules 2022; 27:6224. [PMID: 36234761 PMCID: PMC9571511 DOI: 10.3390/molecules27196224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/07/2022] [Accepted: 09/19/2022] [Indexed: 11/26/2022] Open
Abstract
Benzylamine is a natural molecule present in food and edible plants, capable of activating hexose uptake and inhibiting lipolysis in human fat cells. These effects are dependent on its oxidation by amine oxidases present in adipocytes, and on the subsequent hydrogen peroxide production, known to exhibit insulin-like actions. Virtually, other substrates interacting with such hydrogen peroxide-releasing enzymes potentially can modulate lipid accumulation in adipose tissue. Inhibition of such enzymes has also been reported to influence lipid deposition. We have therefore studied in human adipocytes the lipolytic and lipogenic activities of pharmacological entities designed to interact with amine oxidases highly expressed in this cell type: the semicarbazide-sensitive amine oxidase (SSAO also known as PrAO or VAP-1) and the monoamine oxidases (MAO). The results showed that SZV-2016 and SZV-2017 behaved as better substrates than benzylamine, releasing hydrogen peroxide once oxidized, and reproduced or even exceeded its insulin-like metabolic effects in fat cells. Additionally, several novel SSAO inhibitors, such as SZV-2007 and SZV-1398, have been evidenced and shown to inhibit benzylamine metabolic actions. Taken as a whole, our findings reinforce the list of molecules that influence the regulation of triacylglycerol assembly/breakdown, at least in vitro in human adipocytes. The novel compounds deserve deeper investigation of their mechanisms of interaction with SSAO or MAO, and constitute potential candidates for therapeutic use in obesity and diabetes.
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Affiliation(s)
- Christian Carpéné
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1297, 31432 Toulouse, France
- Team Dinamix, Institute of Metabolic and Cardiovascular Diseases (I2MC), Paul Sabatier University, 31432 Toulouse, France
| | - Pénélope Viana
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1297, 31432 Toulouse, France
- Team Dinamix, Institute of Metabolic and Cardiovascular Diseases (I2MC), Paul Sabatier University, 31432 Toulouse, France
| | - Zsuzsa Iffiú-Soltesz
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1297, 31432 Toulouse, France
| | - Pál Tapolcsányi
- Department of Organic Chemistry, Semmelweis University, H-1092 Budapest, Hungary
| | - Anna Ágota Földi
- Department of Organic Chemistry, Semmelweis University, H-1092 Budapest, Hungary
| | - Péter Mátyus
- Department of Organic Chemistry, Semmelweis University, H-1092 Budapest, Hungary
- E-Group ICT SOFTWARE, H-1027 Budapest, Hungary
| | - Petra Dunkel
- Department of Organic Chemistry, Semmelweis University, H-1092 Budapest, Hungary
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Carpéné C, Stiliyanov Atanasov K, Les F, Mercader Barcelo J. Hyperglycemia and reduced adiposity of streptozotocin-induced diabetic mice are not alleviated by oral benzylamine supplementation. World J Diabetes 2022; 13:752-764. [PMID: 36188146 PMCID: PMC9521444 DOI: 10.4239/wjd.v13.i9.752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/13/2022] [Accepted: 08/22/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Benzylamine (Bza) oral administration delays the onset of hyperglycemia in insulin-resistant db-/- mice; a genetic model of obesity and type 2 diabetes.
AIM To extend the antihyperglycemic properties of oral benzylamine to a model of insulin-deficient type 1 diabetes.
METHODS Male Swiss mice were rendered diabetic by streptozotocin treatment (STZ) and divided in two groups: one received 0.5% Bza as drinking solution for 24 d (STZ Bza-drinking) while the other was drinking water ad libitum. Similar groups were constituted in age-matched, nondiabetic mice. Food intake, liquid intake, body weight gain and nonfasting blood glucose levels were followed during treatment. At the end of treatment, fasted glycemia, liver and white adipose tissue (WAT) mass were measured, while glucose uptake assays were performed in adipocytes.
RESULTS STZ diabetic mice presented typical features of insulin-deficient diabetes: reduced body mass and increased blood glucose levels. These altered parameters were not normalized in the Bza-drinking group in spite of restored food and water intake. Bza consumption could not reverse the severe fat depot atrophy of STZ diabetic mice. In the nondiabetic mice, no difference was found between control and Bza-drinking mice for any parameter. In isolated adipocytes, hexose uptake was partially activated by 0.1 mmol/L Bza in a manner that was obliterated in vitro by the amine oxidase inhibitor phenelzine and that remained unchanged after Bza supplementation. Oxidation of 0.1 mmol/L Bza in WAT was lower in STZ diabetic than in normoglycemic mice.
CONCLUSION Bza supplementation could not normalize the altered glucose handling of STZ diabetic mice with severe WAT atrophy. Consequently, its antidiabetic potential in obese and diabetic rodents does not apply to lipoatrophic type 1 diabetic mice.
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Affiliation(s)
- Christian Carpéné
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR 1297, Toulouse 31432, France
| | - Kristiyan Stiliyanov Atanasov
- Molecular Biology and One Health research group, Department of Fundamental Biology and Health Sciences, University of the Balearic Islands, Palma 07122, Spain
| | - Francisco Les
- Department of Pharmacy, Faculty of Health Sciences, Universidad San Jorge, Villanueva de Gállego, Zaragoza 50830, Spain
| | - Josep Mercader Barcelo
- Molecular Biology and One Health research group, Department of Fundamental Biology and Health Sciences, University of the Balearic Islands, Palma 07122, Spain
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Filip A, Taleb S, Bascetin R, Jahangiri M, Bardin M, Lerognon C, Fève B, Lacolley P, Jalkanen S, Mercier N. Increased atherosclerotic plaque in AOC3 knock-out in ApoE−/− mice and characterization of AOC3 in atherosclerotic human coronary arteries. Front Cardiovasc Med 2022; 9:848680. [PMID: 36176983 PMCID: PMC9513161 DOI: 10.3389/fcvm.2022.848680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 08/04/2022] [Indexed: 11/20/2022] Open
Abstract
Introduction Amine oxidase copper containing 3 (AOC3) displays adhesion between leukocytes and endothelial cells and enzymatic functions. Given its controversial role in atherogenesis, we proposed to investigate the involvement of AOC3 in the formation of atherosclerotic plaques in ApoE−/−AOC3−/− mice and human coronary arteries. Methods Lesions, contractile markers, and AOC3 were studied in aortic tissues from 15- and 25-week-old mice and different stages of human coronary atherosclerotic arteries by immunohistochemistry (IHC) and/or western blot. Human VSMCs, treated or not with LJP1586, an AOC3 inhibitor, were used to measure differentiation markers by qPCR. AOC3 co-localization with specific cell markers was studied by using confocal microscopy in mice and human samples. Results At 15 weeks old, the absence of AOC3 was associated with increased lesion size, α-SMA, and CD3 staining in the plaque independently of a cholesterol modification. At 25 weeks old, advanced plaques were larger with equivalent staining for α-SMA while CD3 increased in the media from ApoE−/−AOC3−/− mice. At both ages, the macrophage content of the lesion was not modified. Contractile markers decreased whereas MCP-1 appeared augmented only in the 15-week-old ApoE−/−AOC3. AOC3 is mainly expressed by mice and human VSMC is slightly expressed by endothelium but not by macrophages. Conclusion AOC3 knock-out increased atherosclerotic plaques at an early stage related to a VSMC dedifferentiation associated with a higher T cells recruitment in plaques explained by the MCP-1 augmentation. This suggests that AOC3 may have an important role in atherosclerosis independent of its canonical inflammatory effect. The dual role of AOC3 impacts therapeutic strategies using pharmacological regulators of SSAO activity.
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Affiliation(s)
- Anna Filip
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Soraya Taleb
- Inserm UMR_S970, Paris Centre de Recherche Cardiovasculaire (PARCC), Paris, France
| | - Rümeyza Bascetin
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Mohammad Jahangiri
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Matthieu Bardin
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Cindy Lerognon
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Bruno Fève
- Sorbonne Université, Inserm UMR_S938, Centre de Recherche Saint Antoine, IHU ICAN, Service d'Endocrinologie, CRMR PRISIS, APHP Hôpital Saint-Antoine, Paris, France
| | - Patrick Lacolley
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
| | - Sirpa Jalkanen
- Medicity Laboratory, University of Turku, Turku, Finland
| | - Nathalie Mercier
- Université de Lorraine, Inserm, Défaillance Cardiovasculaire Aigue et Chronique (DCAC), Université de Lorraine, Lorraine, France
- *Correspondence: Nathalie Mercier
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Carpéné C, Viana P, Fontaine J, Laurell H, Grolleau JL. Multiple Direct Effects of the Dietary Protoalkaloid N-Methyltyramine in Human Adipocytes. Nutrients 2022; 14:nu14153118. [PMID: 35956295 PMCID: PMC9370673 DOI: 10.3390/nu14153118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/23/2022] [Accepted: 07/27/2022] [Indexed: 02/06/2023] Open
Abstract
Dietary amines have been the subject of a novel interest in nutrition since the discovery of trace amine-associated receptors (TAARs), especially TAAR-1, which recognizes tyramine, phenethylamine, tryptamine, octopamine, N-methyltyramine (NMT), synephrine, amphetamine and related derivatives. Alongside the psychostimulant properties of TAAR-1 ligands, it is their ephedrine-like action on weight loss that drives their current consumption via dietary supplements advertised for ‘fat-burning’ properties. Among these trace amines, tyramine has recently been described, at high doses, to exhibit an antilipolytic action and activation of glucose transport in human adipocytes, i.e., effects that are facilitating lipid storage rather than mobilization. Because of its close structural similarity to tyramine, NMT actions on human adipocytes therefore must to be reevaluated. To this aim, we studied the lipolytic and antilipolytic properties of NMT together with its interplay with insulin stimulation of glucose transport along with amine oxidase activities in adipose cells obtained from women undergoing abdominal surgery. NMT activated 2-deoxyglucose uptake when incubated with freshly isolated adipocytes at 0.01–1 mM, reaching one-third of the maximal stimulation by insulin. However, when combined with insulin, NMT limited by half the action of the lipogenic hormone on glucose transport. The NMT-induced stimulation of hexose uptake was sensitive to inhibitors of monoamine oxidases (MAO) and of semicarbazide-sensitive amine oxidase (SSAO), as was the case for tyramine and benzylamine. All three amines inhibited isoprenaline-induced lipolysis to a greater extent than insulin, while they were poorly lipolytic on their own. All three amines—but not isoprenaline—interacted with MAO or SSAO. Due to these multiple effects on human adipocytes, NMT cannot be considered as a direct lipolytic agent, potentially able to improve lipid mobilization and fat oxidation in consumers of NMT-containing dietary supplements.
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Affiliation(s)
- Christian Carpéné
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM U1297), I2MC, CEDEX 4, 31432 Toulouse, France; (P.V.); (J.F.); (H.L.)
- CHU Rangueil, Université Paul Sabatier, I2MC, CEDEX 4, 31432 Toulouse, France
- Correspondence:
| | - Pénélope Viana
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM U1297), I2MC, CEDEX 4, 31432 Toulouse, France; (P.V.); (J.F.); (H.L.)
- CHU Rangueil, Université Paul Sabatier, I2MC, CEDEX 4, 31432 Toulouse, France
| | - Jessica Fontaine
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM U1297), I2MC, CEDEX 4, 31432 Toulouse, France; (P.V.); (J.F.); (H.L.)
- CHU Rangueil, Université Paul Sabatier, I2MC, CEDEX 4, 31432 Toulouse, France
| | - Henrik Laurell
- Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM U1297), I2MC, CEDEX 4, 31432 Toulouse, France; (P.V.); (J.F.); (H.L.)
- CHU Rangueil, Université Paul Sabatier, I2MC, CEDEX 4, 31432 Toulouse, France
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Carpéné C, Marti L, Morin N. Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats. World J Biol Chem 2022; 13:15-34. [PMID: 35126867 PMCID: PMC8790288 DOI: 10.4331/wjbc.v13.i1.15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/09/2021] [Accepted: 01/14/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Despite overt insulin resistance, adipocytes of genetically obese Zucker rats accumulate the excess of calorie intake in the form of lipids.
AIM To investigate whether factors can replace or reinforce insulin lipogenic action by exploring glucose uptake activation by hydrogen peroxide, since it is produced by monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO) in adipocytes.
METHODS 3H-2-deoxyglucose uptake (2-DG) was determined in adipocytes from obese and lean rats in response to insulin or MAO and SSAO substrates such as tyramine and benzylamine. 14C-tyramine oxidation and binding of imidazolinic radioligands [3H-Idazoxan, 3H-(2-benzofuranyl)-2-imidazoline] were studied in adipocytes, the liver, and muscle. The influence of in vivo administration of tyramine + vanadium on glucose handling was assessed in lean and obese rats.
RESULTS 2-DG uptake and lipogenesis stimulation by insulin were dampened in adipocytes from obese rats, when compared to their lean littermates. Tyramine and benzylamine activation of hexose uptake was vanadate-dependent and was also limited, while MAO was increased and SSAO decreased. These changes were adipocyte-specific and accompanied by a greater number of imidazoline I2 binding sites in the obese rat, when compared to the lean. In vitro, tyramine precluded the binding to I2 sites, while in vivo, its administration together with vanadium lowered fasting plasma levels of glucose and triacylglycerols in obese rats.
CONCLUSION The adipocytes from obese Zucker rats exhibit increased MAO activity and imidazoline binding site number. However, probably as a consequence of SSAO down-regulation, the glucose transport stimulation by tyramine is decreased as much as that of insulin in these insulin-resistant adipocytes. The adipocyte amine oxidases deserve more studies with respect to their putative contribution to the management of glucose and lipid handling.
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Affiliation(s)
- Christian Carpéné
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM, Toulouse 31342, France
| | - Luc Marti
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM, Toulouse 31342, France
| | - Nathalie Morin
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM, Toulouse 31342, France
- Faculté de Pharmacie de Paris, Paris University, Paris 75270, France
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Wang H, Poe A, Pak L, Nandakumar K, Jandu S, Steppan J, Löser R, Santhanam L. An in situ activity assay for lysyl oxidases. Commun Biol 2021; 4:840. [PMID: 34226627 PMCID: PMC8257687 DOI: 10.1038/s42003-021-02354-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
The lysyl oxidase family of enzymes (LOXs) catalyze oxidative deamination of lysine side chains on collagen and elastin to initialize cross-linking that is essential for the formation of the extracellular matrix (ECM). Elevated expression of LOXs is highly associated with diverse disease processes. To date, the inability to detect total LOX catalytic function in situ has limited the ability to fully elucidate the role of LOXs in pathobiological mechanisms. Using LOXL2 as a representative member of the LOX family, we developed an in situ activity assay by utilizing the strong reaction between hydrazide and aldehyde to label the LOX-catalyzed allysine (-CHO) residues with biotin-hydrazide. The biotinylated ECM proteins are then labeled via biotin-streptavidin interaction and detected by fluorescence microscopy. This assay detects the total LOX activity in situ for both overexpressed and endogenous LOXs in cells and tissue samples and can be used for studies of LOXs as therapeutic targets.
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Affiliation(s)
- Huilei Wang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Alan Poe
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Lydia Pak
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Kavitha Nandakumar
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Sandeep Jandu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jochen Steppan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Reik Löser
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Lakshmi Santhanam
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA.
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA.
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Semicarbazide-Sensitive Amine Oxidase Increases in Calcific Aortic Valve Stenosis and Contributes to Valvular Interstitial Cell Calcification. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:5197376. [PMID: 32411328 PMCID: PMC7201527 DOI: 10.1155/2020/5197376] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 10/21/2019] [Accepted: 11/26/2019] [Indexed: 12/20/2022]
Abstract
Introduction Calcific aortic valve stenosis (CAVS) is a common disease associated with aging. Oxidative stress participates in the valve calcification process in CAVS. Semicarbazide-sensitive amine oxidase (SSAO), also referred to as vascular adhesion protein 1 (VAP-1), transforms primary amines into aldehydes, generating hydrogen peroxide and ammonia. SSAO is expressed in calcified aortic valves, but its role in valve calcification has remained largely unexplored. The aims of this study were to characterize the expression and the activity of SSAO during aortic valve calcification and to establish the effects of SSAO inhibition on human valvular interstitial cell (VIC) calcification. Methods Human aortic valves from n = 80 patients were used for mRNA extraction and expression analysis, Western blot, SSAO activity determination, immunohistochemistry, and the isolation of primary VIC cultures. Results SSAO mRNA, protein, and activity were increased with increasing calcification within human aortic valves and localized in the vicinity of the calcified zones. The valvular SSAO upregulation was consistent after stratification of the subjects according to cardiovascular and CAVS risk factors associated with increased oxidative stress: body mass index, diabetes, and smoking. SSAO mRNA levels were significantly associated with poly(ADP-ribose) polymerase 1 (PARP1) in calcified tissue. Calcification of VIC was inhibited in the presence of the specific SSAO inhibitor LJP1586. Conclusion The association of SSAO expression and activity with valvular calcification and oxidative stress as well as the decreased VIC calcification by SSAO inhibition points to SSAO as a possible marker and therapeutic target to be further explored in CAVS.
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11
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Serum vascular adhesion protein-1 is up-regulated in hyperglycemia and is associated with incident diabetes negatively. Int J Obes (Lond) 2018; 43:512-522. [PMID: 30022055 DOI: 10.1038/s41366-018-0172-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 06/22/2018] [Accepted: 06/25/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND/OBJECTIVES Vascular adhesion protein-1 (VAP-1) can enhance tissue glucose uptake in cell studies and normalize hyperglycemia in animal studies. However, serum VAP-1 concentration (sVAP-1) is higher in subjects with diabetes in cross-sectional studies. In this cohort study, we test our hypothesis that sVAP-1 is increased in prediabetes to counteract hyperglycemia and is associated with incident diabetes negatively. SUBJECTS/METHODS From 2006 to 2012, 600 subjects without diabetes from Taiwan Lifestyle Study were included and followed regularly. Diabetes was diagnosed if FPG ≥ 126 mg/dL (7 mmol/L), 2-h plasma glucose (2hPG) during an oral glucose tolerance test (OGTT) ≥ 200 mg/dL (11.1 mmol/L), or hemoglobin A1c (HbA1c) ≥ 6.5%, or if the subject received anti-diabetic medications. Abdominal fat areas were measured by abdominal computed tomography and sVAP-1 was analyzed by ELISA. RESULTS sVAP-1 was higher in subjects with prediabetes (p < 0.05) and increased during an OGTT (p < 0.001). Fasting sVAP-1 was associated with the response of sVAP-1 during an OGTT (p < 0.001). Besides, sVAP-1 was associated negatively with body mass index (BMI, r = -0.1449, p = 0.003), waist circumference (r = -0.1425, p = 0.004), abdominal visceral (r = -0.1457, p = 0.003), and subcutaneous (r = -0.1025, p = 0.035) fat areas, and serum high-sensitivity C-reactive protein (hsCRP) concentration (r = -0.2035, p < 0.0001), and positively with plasma adiponectin concentration (r = 0.2086, p < 0.0001), adjusted for age and gender. After 4.7 ± 2.6 years, 73 subjects (12.2%) developed incident diabetes. High sVAP-1 predicted a lower incidence of diabetes, adjusted for age, gender, BMI, family history of diabetes, HbA1c, HOMA2-%B and HOMA2-IR (HR = 0.66, 95% CI = 0.50-0.88, p < 0.01). CONCLUSIONS sVAP-1 is increased in response to hyperglycemia. It is associated with obesity and serum hsCRP concentration negatively, and plasma adiponectin concentration positively. Besides, a high sVAP-1 is associated with a lower incidence of diabetes in human.
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Wang SH, Yu TY, Tsai FC, Weston CJ, Lin MS, Hung CS, Kao HL, Li YI, Solé M, Unzeta M, Chen YL, Chuang LM, Li HY. Inhibition of semicarbazide-sensitive amine oxidase reduces atherosclerosis in apolipoprotein E-deficient mice. Transl Res 2018; 197:12-31. [PMID: 29653075 DOI: 10.1016/j.trsl.2018.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 02/28/2018] [Accepted: 03/18/2018] [Indexed: 01/08/2023]
Abstract
Inflammation, oxidative stress, and formation of advanced glycated end products (AGEs) and advanced lipoxidation end products (ALEs) are important for atherosclerosis. Vascular adhesion protein-1 (VAP-1) participates in inflammation and has semicarbazide-sensitive amine oxidase (SSAO) activity, which catalyzes oxidative deamination to produce hydrogen peroxide and aldehydes, leading to generation of AGEs and ALEs. However, the effect of VAP-1/SSAO inhibition on atherosclerosis remains controversial, and no studies used coronary angiography to evaluate if plasma VAP-1/SSAO is a biomarker for coronary artery disease (CAD). Here, we examined if plasma VAP-1/SSAO is a biomarker for CAD diagnosed by coronary angiography in humans and investigated the effect of VAP-1/SSAO inhibition by a specific inhibitor PXS-4728A on atherosclerosis in cell and animal models. In the study, VAP-1/SSAO expression was increased in plaques in humans and in apolipoprotein E (ApoE)-deficient mice, and colocalized with vascular endothelial cells and smooth muscle cells (SMCs). Patients with CAD had higher plasma VAP-1/SSAO than those without CAD. Plasma VAP-1/SSAO was positively associated with the extent of CAD. In ApoE-deficient mice, VAP-1/SSAO inhibition reduced atheroma and decreased oxidative stress. VAP-1/SSAO inhibition attenuated the expression of adhesion molecules, chemoattractant proteins, and proinflammatory cytokines in the aorta, and suppressed monocyte adhesion and transmigration across human umbilical vein endothelial cells. Consequently, the expression of markers for macrophage recruitment and activation in plaques was decreased by VAP-1/SSAO inhibition. Besides, VAP-1/SSAO inhibition suppressed proliferation and migration of A7r5 SMC. Our data suggest that plasma VAP-1/SSAO is a novel biomarker for the presence and the extent of CAD in humans. VAP-1/SSAO inhibition by PXS-4728A is a potential treatment for atherosclerosis.
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Affiliation(s)
- Shu-Huei Wang
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Tse-Ya Yu
- Health Management Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Feng-Chiao Tsai
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chris J Weston
- Centre for Liver Research, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Mao-Shin Lin
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Sheng Hung
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsien-Li Kao
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-I Li
- Department and Graduate Institute of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Montse Solé
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra (Barcelona), Spain
| | - Mercedes Unzeta
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Bellaterra (Barcelona), Spain
| | - Yuh-Lien Chen
- Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Lee-Ming Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hung-Yuan Li
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
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13
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Inhibition of Semicarbazide-sensitive Amine Oxidase Reduces Atherosclerosis in Cholesterol-fed New Zealand White Rabbits. Sci Rep 2018; 8:9249. [PMID: 29915377 PMCID: PMC6006253 DOI: 10.1038/s41598-018-27551-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 06/05/2018] [Indexed: 01/05/2023] Open
Abstract
Inflammation, oxidative stress, and the formation of advanced glycated end-products (AGEs) are important components of atherosclerosis. Vascular adhesion protein-1 (VAP-1) participates in inflammation. Its enzymatic activity, semicarbazide-sensitive amine oxidase (SSAO), can catalyze oxidative deamination reactions to produce hydrogen peroxide and aldehydes, leading to the subsequent generation of AGEs. This study aimed to investigate the effect of VAP-1/SSAO inhibition on atherosclerosis. In our study, immunohistochemical staining showed that atherosclerotic plaques displayed higher VAP-1 expression than normal arterial walls in apolipoprotein E-deficient mice, cholesterol-fed New Zealand White rabbits and humans. In cholesterol-fed rabbits, VAP-1 was expressed on endothelial cells and smooth muscle cells in the thickened intima of the aorta. Treatment with PXS-4728A, a selective VAP-1/SSAO inhibitor, in cholesterol-fed rabbits significantly decreased SSAO-specific hydrogen peroxide generation in the aorta and reduced atherosclerotic plaques. VAP-1/SSAO inhibition also lowered blood low-density lipoprotein cholesterol, reduced the expression of adhesion molecules and inflammatory cytokines, suppressed recruitment and activation of macrophages, and decreased migration and proliferation of SMC. In conclusion, VAP-1/SSAO inhibition reduces atherosclerosis and may act through suppression of several important mechanisms for atherosclerosis.
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14
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Gonzalez RJ, Lin SA, Bednar B, Connolly B, LaFranco-Scheuch L, Mesfin GM, Philip T, Patel S, Johnson T, Sistare FD, Glaab WE. Vascular Imaging of Matrix Metalloproteinase Activity as an Informative Preclinical Biomarker of Drug-induced Vascular Injury. Toxicol Pathol 2018; 45:633-648. [PMID: 28830331 DOI: 10.1177/0192623317720731] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lack of biomarkers specific to and either predictive or diagnostic of drug-induced vascular injury (DIVI) continues to be a major obstacle during drug development. Biomarkers derived from physiologic responses to vessel injury, such as inflammation and vascular remodeling, could make good candidates; however, they characteristically lack specificity for vasculature. We evaluated whether vascular remodeling-associated protease activity, as well as changes to vessel permeability resulting from DIVI, could be visualized ex vivo in affected vessels, thereby allowing for visual monitoring of the pathology to address specificity. We found that visualization of matrix metalloproteinase activation accompanied by increased vascular leakage in the mesentery of rats treated with agents known to induce vascular injury correlated well with incidence and severity of histopathological findings and associated inflammation as well as with circulating levels of tissue inhibitors of metalloproteinase 1 and neutrophil gelatinase-associated lipocalin. The weight of evidence approach reported here shows promise as a composite DIVI preclinical tool by means of complementing noninvasive monitoring of circulating biomarkers of inflammation with direct imaging of affected vasculature and thus lending specificity to its interpretation. These findings are supportive of a potential strategy that relies on translational imaging tools in conjunction with circulating biomarker data for high-specificity monitoring of VI both preclinically and clinically.
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Affiliation(s)
- Raymond J Gonzalez
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Shu-An Lin
- 2 MRL, West Point, Pennsylvania, USA.,3 Imaging, West Point, Pennsylvania, USA
| | - Bohumil Bednar
- 2 MRL, West Point, Pennsylvania, USA.,3 Imaging, West Point, Pennsylvania, USA
| | - Brett Connolly
- 2 MRL, West Point, Pennsylvania, USA.,3 Imaging, West Point, Pennsylvania, USA
| | - Lisa LaFranco-Scheuch
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Gebre M Mesfin
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Thomas Philip
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Shetal Patel
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Timothy Johnson
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Frank D Sistare
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
| | - Warren E Glaab
- 1 Safety Assessment and Laboratory Animal Resources, West Point, Pennsylvania, USA.,2 MRL, West Point, Pennsylvania, USA
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15
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Horváth Á, Tékus V, Bencze N, Szentes N, Scheich B, Bölcskei K, Szőke É, Mócsai A, Tóth-Sarudy É, Mátyus P, Pintér E, Helyes Z. Analgesic effects of the novel semicarbazide-sensitive amine oxidase inhibitor SZV 1287 in mouse pain models with neuropathic mechanisms: Involvement of transient receptor potential vanilloid 1 and ankyrin 1 receptors. Pharmacol Res 2018; 131:231-243. [DOI: 10.1016/j.phrs.2018.02.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 12/11/2022]
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16
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Ayala-Lopez N, Thompson JM, Watts SW. Perivascular Adipose Tissue's Impact on Norepinephrine-Induced Contraction of Mesenteric Resistance Arteries. Front Physiol 2017; 8:37. [PMID: 28228728 PMCID: PMC5296360 DOI: 10.3389/fphys.2017.00037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/13/2017] [Indexed: 01/22/2023] Open
Abstract
Background: Perivascular adipose tissue (PVAT) can decrease vascular contraction to NE. We tested the hypothesis that metabolism and/or uptake of vasoactive amines by mesenteric PVAT (MPVAT) could affect NE-induced contraction of the mesenteric resistance arteries. Methods: Mesenteric resistance vessels (MRV) and MPVAT from male Sprague-Dawley rats were used. RT-PCR and Western blots were performed to detect amine metabolizing enzymes. The Amplex® Red Assay was used to quantify oxidase activity by detecting the oxidase reaction product H2O2 and the contribution of PVAT on the mesenteric arteries' contraction to NE was measured by myography. Results: Semicarbazide sensitive amine oxidase (SSAO) and monoamine oxidase A (MAO-A) were detected in MRV and MPVAT by Western blot. Addition of the amine oxidase substrates tyramine or benzylamine (1 mM) resulted in higher amine oxidase activity in the MRV, MPVAT, MPVAT's adipocyte fraction (AF), and the stromal vascular fraction (SVF). Inhibiting SSAO with semicarbazide (1 mM) decreased amine oxidase activity in the MPVAT and AF. Benzylamine-driven, but not tyramine-driven, oxidase activity in the MRV was reduced by semicarbazide. By contrast, no reduction in oxidase activity in all sample types was observed with use of the monoamine oxidase inhibitors clorgyline (1 μM) or pargyline (1 μM). Inhibition of MAO-A/B or SSAO individually did not alter contraction to NE. However, inhibition of both MAO and SSAO increased the potency of NE at mesenteric arteries with PVAT. Addition of MAO and SSAO inhibitors along with the H2O2 scavenger catalase reduced PVAT's anti-contractile effect to NE. Inhibition of the norepinephrine transporter (NET) with nisoxetine also reduced PVAT's anti-contractile effect to NE. Conclusions: PVAT's uptake and metabolism of NE may contribute to the anti-contractile effect of PVAT. MPVAT and adipocytes within MPVAT are a source of SSAO.
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Affiliation(s)
- Nadia Ayala-Lopez
- Department of Pharmacology and Toxicology, Michigan State UniversityEast Lansing, MI, USA
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17
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Ayala-Lopez N, Watts SW. New actions of an old friend: perivascular adipose tissue's adrenergic mechanisms. Br J Pharmacol 2016; 174:3454-3465. [PMID: 27813085 DOI: 10.1111/bph.13663] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/03/2016] [Accepted: 10/21/2016] [Indexed: 12/17/2022] Open
Abstract
The revolutionary discovery in 1991 by Soltis and Cassis that perivascular adipose tissue (PVAT) has an anti-contractile effect changed how we think about the vasculature. Most experiments on vascular pharmacology begin by removing the fat surrounding vessels. Thus, PVAT was thought to have a minor role in vascular function and its presence was just for structural support. The need to rethink PVAT's role was precipitated by observations that obesity carries a high cardiovascular risk and PVAT dysfunction is associated with obesity. PVAT is a vascular-adipose organ that has intimate connections with the nervous and immune system. A complex world of physiology resides in PVAT, including the presence of an 'adrenergic system' that is able to release, take up and metabolize noradrenaline. Adipocytes, stromal vascular cells and nerves within PVAT contain components that make up this adrenergic system. Some of the great strides in PVAT research came from studying adipose tissue as a whole. Adipose tissue has many roles and participates in regulating energy balance, energy stores, inflammation and thermoregulation. However, PVAT is dissimilar from non-PVAT adipose tissues. PVAT is intimately connected with the vasculature, which is what makes its role in body homeostasis unique. The adrenergic system within PVAT may be an integral link connecting the effects of obesity with the vascular dysfunction observed in obesity-associated hypertension, a condition in which the sympathetic nervous system has a significant role. This review will explore what is known about the adrenergic system in adipose tissue and PVAT, plus the translational importance of these findings. LINKED ARTICLES This article is part of a themed section on Molecular Mechanisms Regulating Perivascular Adipose Tissue - Potential Pharmacological Targets? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.20/issuetoc.
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Affiliation(s)
- Nadia Ayala-Lopez
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
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Expression of the semicarbazide-sensitive amine oxidase in articular cartilage: its role in terminal differentiation of chondrocytes in rat and human. Osteoarthritis Cartilage 2016; 24:1223-34. [PMID: 26851450 DOI: 10.1016/j.joca.2016.01.340] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 01/15/2016] [Accepted: 01/20/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Semicarbazide-sensitive amine oxidase (SSAO) catalyzes the oxidation of primary amines into ammonia and reactive species (hydrogen peroxide, aldehydes). It is highly expressed in mammalian tissues, especially in vascular smooth muscle cells and adipocytes, where it plays a role in cell differentiation and glucose transport. The study aims at characterizing the expression and the activity of SSAO in rat and human articular cartilage of the knee, and to investigate its potential role in chondrocyte terminal differentiation. DESIGN SSAO expression was examined by immunohistochemistry and western blot. Enzyme activity was measured using radiolabeled benzylamine as a substrate. Primary cell cultures of rat chondrocytes were treated for 21 days by a specific SSAO inhibitor, LJP 1586. Terminal chondrocyte differentiation markers were quantified by RT-qPCR. The basal and IL1β-stimulated glucose transport was monitored by the entrance of (3)[H]2-deoxyglucose in chondrocytes. RESULTS SSAO was expressed in chondrocytes of rat and human articular cartilage. SSAO expression was significantly enhanced during the hypertrophic differentiation of chondrocytes characterized by an increase in MMP13 and in alkaline phosphatase (ALP) expressions. SSAO inhibition delayed the late stage of chondrocyte differentiation without cell survival alteration and diminished the basal and IL1β-stimulated glucose transport. Interestingly, SSAO activity was strongly increased in human osteoarthritic cartilage. CONCLUSIONS SSAO was expressed as an active form in rat and human cartilage. The results suggest the involvement of SSAO in rat chondrocyte terminal differentiation via a modulation of the glucose transport. In man, the increased SSAO activity detected in osteoarthritic patients may trigger hypertrophy and cartilage degeneration.
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Peng Y, Wang J, Zhang M, Niu P, Yang M, Yang Y, Zhao Y. Inactivation of Semicarbazide-Sensitive Amine Oxidase Stabilizes the Established Atherosclerotic Lesions via Inducing the Phenotypic Switch of Smooth Muscle Cells. PLoS One 2016; 11:e0152758. [PMID: 27043821 PMCID: PMC4820117 DOI: 10.1371/journal.pone.0152758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 03/19/2016] [Indexed: 12/11/2022] Open
Abstract
Given that the elevated serum semicarbazide-sensitive amine oxidase (SSAO) activity is associated with the severity of carotid atherosclerosis in clinic, the current study aims to investigate whether SSAO inactivation by semicarbazide is beneficial for established atherosclerotic lesions in LDLr knockout mice on a high-fat/high- cholesterol Western-type diet or after dietary lipid lowering. Despite no impact on plasma total cholesterol levels, the infiltration of circulating monocytes into peripheral tissues, and the size of atherosclerotic lesions, abrogation of SSAO activity resulted in the stabilization of established lesions as evidenced by the increased collagen contents under both conditions. Moreover, SSAO inactivation decreased Ly6Chigh monocytosis and lesion macrophage contents in hypercholesterolemic mice, while no effect was observed in mice after normalization of hypercholesterolemia by dietary lipid lowering. Strikingly, abrogation of SSAO activity significantly increased not only the absolute numbers of smooth muscle cells (SMCs), but also the percent of SMCs with a synthetic phenotype in established lesions of mice regardless of plasma cholesterol levels. Overall, our data indicate that SSAO inactivation in vivo stabilizes the established plaques mainly via inducing the switch of SMCs from a contractile to a synthetic phenotype. Targeting SSAO activity thus may represent a potential treatment for patients with atherosclerosis.
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MESH Headings
- Amine Oxidase (Copper-Containing)/antagonists & inhibitors
- Amine Oxidase (Copper-Containing)/genetics
- Amine Oxidase (Copper-Containing)/metabolism
- Animals
- Atherosclerosis/chemically induced
- Atherosclerosis/enzymology
- Atherosclerosis/genetics
- Atherosclerosis/pathology
- Cell Adhesion Molecules/antagonists & inhibitors
- Cell Adhesion Molecules/genetics
- Cell Adhesion Molecules/metabolism
- Dietary Fats/adverse effects
- Dietary Fats/pharmacology
- Female
- Macrophages/enzymology
- Macrophages/pathology
- Male
- Mice
- Mice, Knockout
- Monocytes/enzymology
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Plaque, Atherosclerotic/chemically induced
- Plaque, Atherosclerotic/enzymology
- Plaque, Atherosclerotic/genetics
- Plaque, Atherosclerotic/pathology
- Receptors, LDL/genetics
- Receptors, LDL/metabolism
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Affiliation(s)
- Ya Peng
- Department of Neurosurgery, The First People’s Hospital of Changzhou, Soochow University, Changzhou, 213003, China
| | - Jun Wang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, 215123, China
| | - Miao Zhang
- Department of Pathophysiology, Soochow University, Suzhou, 215123, China
| | - Panpan Niu
- Department of Neurosurgery, The First People’s Hospital of Changzhou, Soochow University, Changzhou, 213003, China
| | - Mengya Yang
- Department of Neurosurgery, The First People’s Hospital of Changzhou, Soochow University, Changzhou, 213003, China
| | - Yilin Yang
- Department of Neurosurgery, The First People’s Hospital of Changzhou, Soochow University, Changzhou, 213003, China
- Modern Medical Research Center, The First People’s Hospital of Changzhou, Soochow University, Changzhou, 213003, China
- * E-mail: (YZ); (YY)
| | - Ying Zhao
- Department of Pathophysiology, Soochow University, Suzhou, 215123, China
- * E-mail: (YZ); (YY)
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20
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Sun P, Esteban G, Inokuchi T, Marco-Contelles J, Weksler BB, Romero IA, Couraud PO, Unzeta M, Solé M. Protective effect of the multitarget compound DPH-4 on human SSAO/VAP-1-expressing hCMEC/D3 cells under oxygen-glucose deprivation conditions: an in vitro experimental model of cerebral ischaemia. Br J Pharmacol 2015; 172:5390-402. [PMID: 26362823 DOI: 10.1111/bph.13328] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 08/31/2015] [Accepted: 09/03/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Stroke and Alzheimer's disease (AD) are related pathologies in which the cerebrovascular system is involved. Plasma levels of semicarbazide-sensitive amine oxidase/vascular adhesion protein 1 (SSAO/VAP-1, also known as Primary Amine Oxidase -PrAO) are increased in both stroke and AD patients and contribute to the vascular damage. During inflammation, its enzymatic activity mediates leukocyte recruitment to the injured tissue, inducing damage in the blood-brain barrier (BBB) and neuronal tissue. We hypothesized that by altering cerebrovascular function, SSAO/VAP-1 might play a role in the stroke-AD transition. Therefore, we evaluated the protective effect of the novel multitarget-directed ligand DPH-4, initially designed for AD therapy, on the BBB. EXPERIMENTAL APPROACH A human microvascular brain endothelial cell line expressing human SSAO/VAP-1 was generated, as the expression of SSAO/VAP-1 is lost in cultured cells. To simulate ischaemic damage, these cells were subjected to oxygen and glucose deprivation (OGD) and re-oxygenation conditions. The protective role of DPH-4 was then evaluated in the presence of methylamine, an SSAO substrate, and/or β-amyloid (Aβ). KEY RESULTS Under our conditions, DPH-4 protected brain endothelial cells from OGD and re-oxygenation-induced damage, and also decreased SSAO-dependent leukocyte adhesion. DPH-4 was also effective at preventing the damage induced by OGD and re-oxygenation in the presence of Aβ as a model of AD pathology. CONCLUSIONS AND IMPLICATIONS From these results, we concluded that the multitarget compound DPH-4 might be of therapeutic benefit to delay the onset and/or progression of the neurological pathologies associated with stroke and AD, which appear to be linked.
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Affiliation(s)
- P Sun
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular. Edifici M, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - G Esteban
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular. Edifici M, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - T Inokuchi
- Division of Chemistry and Biotechnology, Graduate School of Natural Science and Technology, Okayama University, 3.1.1 Tsushima-Naka, Kita-ku, Okayama, 700-8530, Japan
| | - J Marco-Contelles
- Instituto de Química Orgánica General (CSIC), 3 Juan de la Cierva, Madrid, 28006, Spain
| | - B B Weksler
- Department of Medicine, Division of Hematology-Oncology, Weill Cornell Medical College, New York, NY, 10065, USA
| | - I A Romero
- Department of Life, Health and Chemical Sciences, Open University, Milton Keynes, UK
| | - P O Couraud
- Institut Cochin, INSERM U1016, CNRS UMR 8104, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - M Unzeta
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular. Edifici M, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - M Solé
- Institut de Neurociències i Departament de Bioquímica i Biologia Molecular. Edifici M, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
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Karim S, Liaskou E, Fear J, Garg A, Reynolds G, Claridge L, Adams DH, Newsome PN, Lalor PF. Dysregulated hepatic expression of glucose transporters in chronic disease: contribution of semicarbazide-sensitive amine oxidase to hepatic glucose uptake. Am J Physiol Gastrointest Liver Physiol 2014; 307:G1180-90. [PMID: 25342050 PMCID: PMC4269679 DOI: 10.1152/ajpgi.00377.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Insulin resistance is common in patients with chronic liver disease (CLD). Serum levels of soluble vascular adhesion protein-1 (VAP-1) are also increased in these patients. The amine oxidase activity of VAP-1 stimulates glucose uptake via translocation of transporters to the cell membrane in adipocytes and smooth muscle cells. We aimed to document human hepatocellular expression of glucose transporters (GLUTs) and to determine if VAP-1 activity influences receptor expression and hepatic glucose uptake. Quantitative PCR and immunocytochemistry were used to study human liver tissue and cultured cells. We also used tissue slices from humans and VAP-1-deficient mice to assay glucose uptake and measure hepatocellular responses to stimulation. We report upregulation of GLUT1, -3, -5, -6, -7, -8, -9, -10, -11, -12, and -13 in CLD. VAP-1 expression and enzyme activity increased in disease, and provision of substrate to hepatic VAP-1 drives hepatic glucose uptake. This effect was sensitive to inhibition of VAP-1 and could be recapitulated by H2O2. VAP-1 activity also altered expression and subcellular localization of GLUT2, -4, -9, -10, and -13. Therefore, we show, for the first time, alterations in hepatocellular expression of glucose and fructose transporters in CLD and provide evidence that the semicarbazide-sensitive amine oxidase activity of VAP-1 modifies hepatic glucose homeostasis and may contribute to patterns of GLUT expression in chronic disease.
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Affiliation(s)
- Sumera Karim
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - Evaggelia Liaskou
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - Janine Fear
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - Abhilok Garg
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - Gary Reynolds
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - Lee Claridge
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
| | - David H. Adams
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and ,2Liver and Hepatobiliary Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom
| | - Philip N. Newsome
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and ,2Liver and Hepatobiliary Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom
| | - Patricia F. Lalor
- 1Centre for Liver Research and National Institute for Health Research Biomedical Research Unit, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom; and
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Januszewski AS, Mason N, Karschimkus CS, Rowley KG, Best JD, O'Neal DN, Jenkins AJ. Plasma semicarbazide-sensitive amine oxidase activity in type 1 diabetes is related to vascular and renal function but not to glycaemia. Diab Vasc Dis Res 2014; 11:262-269. [PMID: 24853908 DOI: 10.1177/1479164114532963] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE Associations of semicarbazide-sensitive amine oxidase (SSAO) activity with renal and vascular function, oxidative stress, glycaemia and diabetes complications were determined. METHODS Plasma SSAO activity in 94 type 1 diabetes (T1DM) patients, including 34 with microvascular complications T1DM CX[+], and in 96 healthy subjects (CON) was measured by production of benzaldehyde using high-performance liquid chromatography (HPLC). RESULTS SSAO activity (mean ± SD) was greater in T1DM than in CON (1049 ± 294 vs 749 ± 204 mU/L; p < 0.00001) and was higher in T1DM CX[+] vs complication-free DM subjects (1148 ± 313 mU/L vs 982 ± 269 mU/L; p = 0.01). In T1DM, SSAO activity correlated with renal dysfunction [estimated glomerular filtration rate (eGFR): r = -0.44; p = 0.0001; cystatin C: r = 0.47; p = 0.0001] and markers of inflammation [soluble vascular cell adhesion molecule-1 (sVCAM-1): r = 0.41, p = 0.0001; soluble intercellular adhesion molecule-1 (sICAM-1): r = 0.33, p = 0.002] and was inversely related to small artery elasticity (SAE) (r = -0.23, p = 0.03). In CON, SSAO activity correlated with HbA1c (r = 0.26; p = 0.02). CONCLUSION In T1DM, SSAO activity correlates with renal dysfunction, but not with glycaemia, and may promote vascular inflammation and be a therapeutic target.
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Affiliation(s)
- Andrzej S Januszewski
- NHMRC Clinical Trials Centre, University of Sydney, Camperdown, NSW, Australia Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Nick Mason
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Connie S Karschimkus
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Kevin G Rowley
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - James D Best
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - David N O'Neal
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Alicia J Jenkins
- NHMRC Clinical Trials Centre, University of Sydney, Camperdown, NSW, Australia Department of Medicine, St Vincent's Hospital, University of Melbourne, Melbourne, Australia
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Wong MYW, Saad S, Pollock C, Wong MG. Semicarbazide-sensitive amine oxidase and kidney disease. Am J Physiol Renal Physiol 2013; 305:F1637-44. [PMID: 24173357 DOI: 10.1152/ajprenal.00416.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
With better understanding of the molecular mechanisms underpinning chronic kidney disease, the roles of inflammation and fibrosis are becoming increasingly inseparable. The progression of renal disease is characterized by pathomorphological changes that consist of early inflammatory responses followed by tubulointerstitial fibrosis, tubular atrophy, and glomerular and vascular sclerosis. Currently available therapies that reduce hypertension, proteinuria, hyperglycemia, and interruption of the renin-angiotensin-aldosterone system are at best only partially effective. Hence, there remains a need to explore agents targeting nonrenin-angiotensin-aldosterone system pathways. In this review, we discuss mechanistic aspects in the physiological and pathological role of semicarbazide-sensitive amine oxidase, a protein enzyme involved in cellular trafficking and inflammation, with respect to the kidney. We explore the evidence for the use of semicarbazide-sensitive amine oxidase inhibitors as potential agents in renal fibrosis to delay the onset and progression of chronic kidney disease.
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Affiliation(s)
- May Y W Wong
- Kolling Institute of Medical Research, Level 7 Kolling Bldg., Royal North Shore Hospital, St Leonards 2065, NSW, Australia.
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Coen M, Burkhardt K, Bijlenga P, Gabbiani G, Schaller K, Kövari E, Rüfenacht DA, Ruíz DSM, Pizzolato G, Bochaton-Piallat ML. Smooth muscle cells of human intracranial aneurysms assume phenotypic features similar to those of the atherosclerotic plaque. Cardiovasc Pathol 2013; 22:339-44. [DOI: 10.1016/j.carpath.2013.01.083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/16/2013] [Accepted: 01/25/2013] [Indexed: 11/29/2022] Open
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Carpéné C, Desquesnes A, Gomez-Ruiz A, Iffiú-Soltész Z, Le Gonidec S, Mercader J. Long-term activation of semicarbazide-sensitive amine oxidase lowers circulating levels of uric acid in diabetic conditions. Physiol Res 2012; 61:251-7. [PMID: 22480418 DOI: 10.33549/physiolres.932211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Uric acid is involved in nitrogenous waste in animals, together with ammonia and urea. Uric acid has also antioxidant properties and is a surrogate marker of metabolic syndrome. We observed that the elevated plasma uric acid of high-fat fed mice was normalized by benzylamine treatment. Indeed, benzylamine is the reference substrate of semicarbazide-sensitive amine oxidase (SSAO), an enzyme highly expressed in fat depots and vessels, which generates ammonia when catalysing oxidative deamination. Ammonia interferes with uric acid metabolism/solubility. Our aim was therefore to investigate whether the lowering action of benzylamine on uric acid was related to an improvement of diabetic complications, or was connected with SSAO-dependent ammonia production. First, we observed that benzylamine administration lowered plasma uric acid in diabetic db/db mice while it did not modify uric acid levels in normoglycemic and lean mice. In parallel, benzylamine improved the glycemic control in diabetic but not in normoglycemic mice, while plasma urea remained unaltered. Then, uric acid plasma levels were measured in mice invalidated for AOC3 gene, encoding for SSAO. These mice were unable to oxidize benzylamine but were not diabetic and exhibited unaltered plasma uric levels. Therefore, activated or abolished ammonia production by SSAO was without influence on uric acid in the context of normoglycemia. Our observations confirm that plasma uric acid increases with diabetes and can be normalized when glucose tolerance is improved. They also show that uric acid, a multifunctional metabolite at the crossroads of nitrogen waste and of antioxidant defences, can be influenced by SSAO, in a manner apparently related to changes in glucose homeostasis.
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Affiliation(s)
- C Carpéné
- INSERM U1048 équipe 3, I2MC, Bat. L4, CHU Rangueil, BP 84225, Toulouse Cedex 4, France.
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Vascular cell lines expressing SSAO/VAP-1: a new experimental tool to study its involvement in vascular diseases. Biol Cell 2012; 103:543-57. [PMID: 21819380 DOI: 10.1042/bc20110049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND INFORMATION PrAO (primary amine oxidase), also known as SSAO (semicarbazide-sensitive amine oxidase)/VAP-1 (vascular adhesion protein-1), is an enzyme (EC 1.4.3.21) that is highly expressed in blood vessels and participates in many cell processes, including glucose handling or inflammatory leucocyte recruitment. High activity levels of this enzyme are associated with diabetes, atherosclerosis, AD (Alzheimer's disease) or stroke, among others, thus meaning that studies concerning SSAO as a therapeutic target are becoming more frequent. However, the study of this enzyme is difficult, owing to its loss of expression in cell cultures. RESULTS We have developed an endothelial cell line that stably expresses the human SSAO/VAP-1 to be used as endothelial cell model for the study of this enzyme. The transfected protein is mainly expressed as a dimer in the membrane of these cells, and we demonstrate its specific localization in the lipid rafts of endothelial cells. The protein shows levels of enzymatic activity and kinetic parameters comparable with those observed in vivo by the same cell type. The transfected SSAO/VAP-1 is also able to mediate the adhesion of leucocytes to the endothelium, a known function of this protein under inflammatory conditions. This distinctive function is not exerted by the SSAO/VAP-1 transfected protein in a smooth muscle cell line that expresses 3-fold higher protein levels. These differences have been widely reported to exist in vivo. Furthermore, using this endothelial cell model, we describe for the first time the involvement of the leucocyte-adhesion activity of SSAO/VAP-1 in the Aβ (amyloid β-peptide)-mediated pro-inflammatory effect. CONCLUSIONS The characterization of this new cell line shows the correct behaviour of the transfected protein and endorses the use of these cellular models for the in-depth study of the currently poorly understood functions of SSAO/VAP-1 and its involvement in the above-mentioned pathologies. This cellular model will be also useful for the evaluation of potential compounds that could modulate its activity for therapeutic purposes.
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Lin Z, Han M, Li H, Luo H, Zhang Y, Luo W. Soluble vascular adhesion protein-1: decreased activity in the plasma of trauma victims and predictive marker for severity of traumatic brain injury. Clin Chim Acta 2011; 412:1678-82. [PMID: 21645499 DOI: 10.1016/j.cca.2011.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 05/06/2011] [Accepted: 05/23/2011] [Indexed: 02/05/2023]
Abstract
BACKGROUND This study done was to investigate the clinical significance of soluble vascular adhesion protein-1 (sVAP-1) activity in trauma patients with different patterns. METHODS 96 patients with consecutive trauma ≥15 years who were admitted to emergency department of the Second Affiliated Hospital, Shantou University Medical College, China, between January 2007 and December 2009 were enrolled in this study. Plasma was collected at admission. Injury-severity score (ISS) and Glasgow Coma Scale (GCS) were used to determine the patient conditions. sVAP-1 activity was determined by using the high performance liquid chromatographic (HPLC) system. RESULTS Mean sVAP-1 activity in trauma patients was significantly lower than that of controls (P<0.0001), and the level was negatively correlated with circulating leucocytes and neutrophils (P<0.0001). There was a significant correlation between lower sVAP-1 activity and injury patterns. However, plasma sVAP-1 activity increased significantly in accordance with the severity of traumatic brain injury (TBI), and the patients with sVAP-1 value above 8.61 nmol/ml/h have much higher mortality rate (25.0%) than patients with sVAP-1 value lower than 8.61 nmol/ml/h (0.0%) (P=0.011). CONCLUSIONS Trauma patients had a decreased sVAP-1 activity. However, isolated TBI patients with higher activity of sVAP-1 at admission were more likely to have a poor outcome.
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Affiliation(s)
- Zhexuan Lin
- Bio-analytical Laboratory, Shantou University Medical College, Shantou, Guangdong Province, China
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Lin Z, Li H, Luo H, Zhang Y, Luo W. Benzylamine and methylamine, substrates of semicarbazide-sensitive amine oxidase, attenuate inflammatory response induced by lipopolysaccharide. Int Immunopharmacol 2011; 11:1079-89. [PMID: 21414430 DOI: 10.1016/j.intimp.2011.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 02/17/2011] [Accepted: 03/01/2011] [Indexed: 02/05/2023]
Abstract
Current evidence indicates that semicarbazide-sensitive amine oxidase (SSAO) substrates possess insulin-mimic effect, which was thought to play an anti-inflammatory role. The purpose of the present study was to determine whether SSAO substrates benzylamine (BZA) and methylamine (MA) attenuate inflammatory response induced by lipopolysaccharide (LPS). BALB/c mice peritoneal macrophages (PMs) that express SSAO and RAW264.7 mouse macrophages that do not express SSAO were used in vitro studies. Experimental mice were given BZA or MA through intraperitoneal injection before LPS challenge. The results showed that BZA or MA treatment significantly reduced LPS-induced pro-inflammatory mediators (nitric oxide, TNF-α) production, the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, and glucose consumption in murine PMs, but not in RAW264.7 cell line. The metabolites of BZA or MA catalyzed by SSAO, hydrogen peroxide, formaldehyde, and benzaldehyde could also significantly decrease LPS-induced nitric oxide and TNF-α production, iNOS and COX-2 expression, and glucose consumption in vitro. In addition, BZA or MA administration could significantly decrease plasma pro-inflammatory mediators and the expression of iNOS and COX-2 in liver and lung, and could also attenuate LPS-induced transient hyperglycemia and chronic hypoglycemia. These findings indicated that substrates of SSAO might be involved in the anti-inflammatory effects. The metabolites of BZA and MA catalyzed by SSAO might be responsible for the anti-inflammatory effects. Moreover, BZA or MA administration could be useful for normalization of glucose disposal during endotoxemia.
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Affiliation(s)
- Zhexuan Lin
- Bio-analytical Laboratory, Shantou University Medical College, Shantou, PR China
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SSAO substrates exhibiting insulin-like effects in adipocytes as a promising treatment option for metabolic disorders. Future Med Chem 2011; 2:1735-49. [PMID: 21428797 DOI: 10.4155/fmc.10.260] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Benzylamine exerts insulin-like effects in adipocytes (e.g., glucose uptake and antilipolysis) and improves glucose handling in rodents. RESULTS In murine adipocytes, benzylamine mimics another insulin action: it enhances apelin expression in a manner that is blocked by the semicarbazide-sensitive amine oxidase/vascular adhesion protein-1 (SSAO/VAP-1) inhibitor semicarbazide. It is shown that in human adipocytes, benzylamine activates glucose transport, but its effects are not additive to maximal insulin stimulation. Benzylamine effects are hydrogen peroxide dependent. They can be reproduced by novel substrates, but not by benzaldehyde. CONCLUSION Owing to the parallelism between the in vitro insulin mimicry and the in vivo improvement of glucose handling elicited by benzylamine in rodents, the SSAO/VAP-1 substrates, with stronger effects on human adipocytes than benzylamine, show promising applications for the treatment of insulin resistance.
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Olivieri A, Rico D, Khiari Z, Henehan G, O'Sullivan J, Tipton K. From caffeine to fish waste: amine compounds present in food and drugs and their interactions with primary amine oxidase. J Neural Transm (Vienna) 2011; 118:1079-89. [PMID: 21373760 DOI: 10.1007/s00702-011-0611-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 02/16/2011] [Indexed: 12/29/2022]
Abstract
Tissue bound primary amine oxidase (PrAO) and its circulating plasma-soluble form are involved, through their catalytic activity, in important cellular roles, including the adhesion of lymphocytes to endothelial cells during various inflammatory conditions, the regulation of cell growth and maturation, extracellular matrix deposition and maturation and glucose transport. PrAO catalyses the oxidative deamination of several xenobiotics and has been linked to vascular toxicity, due to the generation of cytotoxic aldehydes. In this study, a series of amines and aldehydes contained in food and drugs were tested via a high-throughput assay as potential substrates or inhibitors of bovine plasma PrAO. Although none of the compounds analyzed were found to be substrates for the enzyme, a series of molecules, including caffeine, the antidiabetics phenformin and tolbutamide and the antimicrobial pentamidine, were identified as PrAO inhibitors. Although the inhibition observed was in the millimolar and micromolar range, these data show that further work will be necessary to elucidate whether the interaction of ingested biogenic or xenobiotic amines with PrAO might adversely affect its biological roles.
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Affiliation(s)
- Aldo Olivieri
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland.
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Desai KM, Chang T, Wang H, Banigesh A, Dhar A, Liu J, Untereiner A, Wu L. Oxidative stress and aging: is methylglyoxal the hidden enemy? Can J Physiol Pharmacol 2011; 88:273-84. [PMID: 20393592 DOI: 10.1139/y10-001] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Aging is a multifactorial process that involves changes at the cellular, tissue, organ and the whole body levels resulting in decreased functioning, development of diseases, and ultimately death. Oxidative stress is believed to be a very important factor in causing aging and age-related diseases. Oxidative stress is caused by an imbalance between oxidants such as reactive oxygen species (ROS) and antioxidants. ROS are produced from the mitochondrial electron transport chain and many oxidative reactions. Methylglyoxal (MG) is a highly reactive dicarbonyl metabolite formed during glucose, protein and fatty acid metabolism. MG levels are elevated in hyperglycemia and other conditions. An excess of MG formation can increase ROS production and cause oxidative stress. MG reacts with proteins, DNA and other biomolecules, and is a major precursor of advanced glycation end products (AGEs). AGEs are also associated with the aging process and age-related diseases such as cardiovascular complications of diabetes, neurodegenerative diseases and connective tissue disorders. AGEs also increase oxidative stress. In this review we discuss the potential role of MG in the aging process through increasing oxidative stress besides causing AGEs formation. Specific and effective scavengers and crosslink breakers of MG and AGEs are being developed and can become potential treatments to slow the aging process and prevent many diseases.
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Affiliation(s)
- Kaushik M Desai
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
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Mercader J, Iffiú-Soltész Z, Bour S, Carpéné C. Oral Administration of Semicarbazide Limits Weight Gain together with Inhibition of Fat Deposition and of Primary Amine Oxidase Activity in Adipose Tissue. J Obes 2011; 2011:475786. [PMID: 21331292 PMCID: PMC3038600 DOI: 10.1155/2011/475786] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 12/22/2010] [Indexed: 12/29/2022] Open
Abstract
An enzyme hitherto named semicarbazide-sensitive amine oxidase (SSAO), involved in the oxidation of primary amines, is abundantly expressed in adipocytes. Although SSAO physiological functions remain unclear, several molecules inhibiting its activity have been described to limit fat accumulation in preadipocyte cultures or to reduce body weight gain in obese rodents. Here, we studied whether oral administration of semicarbazide, a prototypical SSAO inhibitor, limits fat deposition in mice. Prolonged treatment with semicarbazide at 0.125% in drinking water limited food and water consumption, hampered weight gain, and deeply impaired fat deposition. The adiposomatic index was reduced by 31%, while body mass was reduced by 15%. Such treatment completely inhibited SSAO, but did not alter MAO activity in white adipose tissue. Consequently, the insulin-like action of the SSAO substrate benzylamine on glucose transport was abolished in adipocytes from semicarbazide-drinking mice, while their insulin sensitivity was not altered. Although semicarbazide is currently considered as a food contaminant with deleterious effects, the SSAO inhibition it induces appears as a novel concept to modulate adipose tissue development, which is promising for antiobesity drug discovery.
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Affiliation(s)
- Josep Mercader
- Institut National de la Santé et de la Recherche Médicale, INSERM U1048, Equipe 3, 12MC, IFR 150, Bat. L4, CHU Rangueil, BP 84225, 31432 Toulouse Cedex 4, France
- Université Paul Sabatier, 12MC, Centre Hospitalier Universitaire de Rangueil, 31432 Toulouse, France
| | - Zsuzsa Iffiú-Soltész
- Institut National de la Santé et de la Recherche Médicale, INSERM U1048, Equipe 3, 12MC, IFR 150, Bat. L4, CHU Rangueil, BP 84225, 31432 Toulouse Cedex 4, France
- Université Paul Sabatier, 12MC, Centre Hospitalier Universitaire de Rangueil, 31432 Toulouse, France
| | - Sandy Bour
- Université Paul Sabatier, 12MC, Centre Hospitalier Universitaire de Rangueil, 31432 Toulouse, France
| | - Christian Carpéné
- Institut National de la Santé et de la Recherche Médicale, INSERM U1048, Equipe 3, 12MC, IFR 150, Bat. L4, CHU Rangueil, BP 84225, 31432 Toulouse Cedex 4, France
- Université Paul Sabatier, 12MC, Centre Hospitalier Universitaire de Rangueil, 31432 Toulouse, France
- *Christian Carpéné:
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Sibon I, Mercier N, Darret D, Lacolley P, Lamazière JMD. Association between semicarbazide-sensitive amine oxidase, a regulator of the glucose transporter, and elastic lamellae thinning during experimental cerebral aneurysm development. J Neurosurg 2008; 108:558-66. [DOI: 10.3171/jns/2008/108/3/0558] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Amine oxidases play a key role in the polymerization and cross-linking of the collagens and elastic lamellae of the arterial wall. The loss of elastic lamellae integrity is one of the first steps in the genesis of a cerebral aneurysm. The authors investigated the relation between semicarbazide-sensitive amine oxidase (SSAO) and the organization of the cerebral arterial wall during aneurysm development.
Methods
Intracranial aneurysms were induced in rats via unilateral carotid artery ligation and renovascular hypertension. This modified Hashimoto model was used to create elevated blood pressure associated with shear stress in cerebral arteries. The authors immunohistologically investigated some markers of the extracellular matrix (Types I, III, and IV collagen and elastin), vascular smooth muscle cell differentiation (smooth muscle myosin heavy chain [sm-MHC], α–smooth muscle actin, and desmin), and amine oxidases (SSAO and lysyl oxidase [LOX]) in the cerebral arterial wall in control and treated rats 1, 2, 3, 4, and 6 months after the surgical procedure.
Results
The authors found severe disorganization and thinning of the elastic lamellae and a dramatic reduction in SSAO activity and immunostaining during cerebral aneurysm development. In contrast, LOX markers were slightly increased. Elastic lamellae thinning was highly correlated with decreases in SSAO (r = 0.76, p < 0.0001). There was also a correlation between sm-MHC and SSAO levels.
Conclusions
The data suggested that cerebral hemodynamic modifications induce decreases in SSAO activity resulting in cell dedifferentiation and inducing dysregulation of glucose transport.
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Affiliation(s)
- Igor Sibon
- 1Institut National de la Santé et de la Recherche Médicale U828, Université Victor Segalen Bordeaux 2; and
| | - Nathalie Mercier
- 2Institut National de la Santé et de la Recherche Médicale U684, Université Nancy, France
| | - Danièle Darret
- 1Institut National de la Santé et de la Recherche Médicale U828, Université Victor Segalen Bordeaux 2; and
| | - Patrick Lacolley
- 2Institut National de la Santé et de la Recherche Médicale U684, Université Nancy, France
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Solé M, Hernandez-Guillamon M, Boada M, Unzeta M. p53 phosphorylation is involved in vascular cell death induced by the catalytic activity of membrane-bound SSAO/VAP-1. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1085-94. [PMID: 18348872 DOI: 10.1016/j.bbamcr.2008.02.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/30/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
Abstract
Semicarbazide sensitive amine oxidase (SSAO) is a multifunctional enzyme present mainly in adipocytes, endothelial and smooth muscle cells. It metabolizes primary aliphatic and aromatic amines generating products able to contribute to cellular oxidative stress. SSAO is expressed in a membrane-bound form and is also present as a soluble enzyme in plasma. Both isoforms are increased in several pathologies, and the catalytic products generated by the soluble enzymatic activity can induce cytotoxicity of vascular cells in culture. We have analyzed whether the transmembrane form of the enzyme is able to produce a cytotoxic effect through methylamine oxidation. Since cells in culture lose the expression of this enzyme, we used an SSAO stably transfected smooth muscle cell line. Herein we report that cell treatment with the substrate methylamine induced a dose and time dependent cytotoxic effect. The tumor suppressor protein p53 played an important role in the molecular pathway involved in this cell death. Moreover, we also observed the induction of PUMA-alpha expression with mitochondrial Bcl-2 family proteins being affected, and final effector caspases being activated.
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Affiliation(s)
- Montse Solé
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, (08193) Bellaterra, Barcelona, Spain.
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O'Rourke AM, Wang EY, Miller A, Podar EM, Scheyhing K, Huang L, Kessler C, Gao H, Ton-Nu HT, Macdonald MT, Jones DS, Linnik MD. Anti-inflammatory effects of LJP 1586 [Z-3-fluoro-2-(4-methoxybenzyl)allylamine hydrochloride], an amine-based inhibitor of semicarbazide-sensitive amine oxidase activity. J Pharmacol Exp Ther 2008; 324:867-75. [PMID: 17993604 DOI: 10.1124/jpet.107.131672] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Semicarbazide-sensitive amine oxidase (SSAO, amine oxidase, copper-containing 3, and vascular adhesion protein-1) is a copper-containing enzyme that catalyzes the oxidative deamination of primary amines to an aldehyde, ammonia, and hydrogen peroxide. SSAO is also involved in leukocyte migration to sites of inflammation, and the enzymatic activity of SSAO is essential to this role. Thus, inhibition of SSAO enzyme activity represents a target for the development of small molecule anti-inflammatory compounds. Here, we have characterized the novel SSAO inhibitor, Z-3-fluoro-2-(4-methoxybenzyl)allylamine hydrochloride (LJP 1586), and assessed its anti-inflammatory activity. LJP 1586 is a potent inhibitor of rodent and human SSAO activity, with IC(50) values between 4 and 43 nM. The selectivity of LJP 1586 was confirmed with a broad panel of receptors and enzymes that included the monoamine oxidases A and B. Oral administration of LJP 1586 resulted in complete inhibition of rat lung SSAO, with an ED(50) between 0.1 and 1 mg/kg, and a pharmacodynamic half-life of greater than 24 h. In a mouse model of inflammatory leukocyte trafficking oral dosing with LJP 1586 resulted in significant dose-dependent inhibition of neutrophil accumulation, with an effect comparable to that of anti-leukocyte function-associated antigen-1 antibody. In a rat model of LPS-induced lung inflammation, administration of 10 mg/kg LJP 1586 resulted in a 55% significant reduction in transmigrated cells recovered by bronchoalveolar lavage. The results demonstrate that a selective, orally active small molecule inhibitor of SSAO is an effective anti-inflammatory compound in vivo and provide further support for SSAO as a therapeutic anti-inflammatory target.
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Affiliation(s)
- Anne M O'Rourke
- La Jolla Pharmaceutical Company, 6455 Nancy Ridge Drive, San Diego, CA 92121, USA.
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McDonald A, Tipton K, O'Sullivan J, Olivieri A, Davey G, Coonan AM, Fu W. Modelling the roles of MAO and SSAO in glucose transport. J Neural Transm (Vienna) 2007; 114:783-6. [PMID: 17406961 DOI: 10.1007/s00702-007-0688-6] [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: 11/21/2006] [Accepted: 12/20/2006] [Indexed: 12/29/2022]
Abstract
Amine oxidase substrates such as benzylamine and methylamine have been shown to stimulate glucose uptake by increasing the recruitment of the glucose transporter GLUT4 from vesicles within the cell to the cell surface. Inhibition of this effect by the presence of semicarbazide and catalase led to the suggestion that the process is mediated by the H(2)O(2) produced in the oxidation of these amines. Tyramine, which is a substrate for both MAO and SSAO, can also stimulate this process and in that case both MAO and SSAO inhibitors attenuate the effect. Benzylamine does not occur physiologically and tyramine is normally present in only very low amounts. We have suggested that adrenaline, which also stimulates glucose metabolism through adrenoceptors, may act as the physiological substrate for GLUT4 recruitment. It is a substrate for MAO but not SSAO. However, oxidation of adrenaline by MAO releases both H(2)O(2) and methylamine for further oxidation by SSAO. In order to gain a fuller understanding of this process we have performed simulation studies that may be used to assess the contributions of the amine oxidases to the process under a variety of conditions. The results are consistent with the experimentally observed behaviour. This approach not only helps to establish the feasibility of this process but also allows behaviour prediction and the identification of further experimental approaches.
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Affiliation(s)
- A McDonald
- Department of Biochemistry, School of Biochemistry and Immunology, Trinity College, Dublin, Ireland.
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38
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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: 31] [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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39
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Hernandez M, Solé M, Boada M, Unzeta M. Soluble Semicarbazide Sensitive Amine Oxidase (SSAO) catalysis induces apoptosis in vascular smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:164-73. [PMID: 16448709 DOI: 10.1016/j.bbamcr.2005.11.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 11/22/2005] [Accepted: 11/29/2005] [Indexed: 10/25/2022]
Abstract
Semicarbazide sensitive amine oxidase (SSAO) metabolizes oxidative deamination of primary aromatic and aliphatic amines. It is selectively expressed in vascular cells of blood vessels, but it is also circulating in blood plasma. SSAO activity in plasma is increased in some diseases associated with vascular complications and its catalytic products may cause tissue damage. We examined the effect of the oxidation of the SSAO substrate, methylamine, on cultured smooth muscle cells. Cell incubation with methylamine plus soluble SSAO, contained in bovine serum, resulted toxic to rat aorta A7r5 and human aortic smooth muscle cells, as measured by MTT reduction. This effect was completely reverted by specific SSAO inhibitors, indicating that the toxicity was mediated by the end products generated. Moreover, SSAO-mediated deamination of methylamine induced apoptosis in A7r5 cells, detected by chromatin condensation, Caspase-3 activation, PARP cleavage and cytochrome c release to cytosol. Formaldehyde, rather than H2O2, resulted to be a strong apoptotic inducer to A7r5 cells. Taken together, the results suggest that increased plasma SSAO activity in pathological conditions, could contribute to apoptosis in smooth muscle cells, leading to vascular tissue damage.
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Affiliation(s)
- Mar Hernandez
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona, (08193) Bellaterra, Barcelona, Spain
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40
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Visentin V, Boucher J, Bour S, Prévot D, Castan I, Carpéné C, Valet P. Influence of high-fat diet on amine oxidase activity in white adipose tissue of mice prone or resistant to diet-induced obesity. J Physiol Biochem 2005; 61:343-52. [PMID: 16180332 DOI: 10.1007/bf03167051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Decreased monoamine oxidase (MAO) activity has been observed in adipose tissue of obese patients. Since substrates of MAO and semicarbazide-sensitive amine oxidase (SSAO) can modify adipocyte metabolism, this work investigates whether changes in amine oxidase activity may occur during white adipose tissue (WAT) development. We evaluated MAO and SSAO activities in WAT of high-fat diet (HFD) and low-fat diet fed mice. To distinguish the effect of HFD on its own from the effect of fat mass enlargement, obesity-prone transgenic line of the FVBn strain lacking beta3-adrenergic receptors (AR) but expressing human beta3-AR and alpha2-AR (mbeta3-/-, hbeta3+/+, halpha2+/-) was compared to its obesity-resistant control (mbeta3-/-, hbeta3+/+). As already reported, the former mice became obese while the latter resisted to HFD. No significant change in SSAO or MAO activity was found in WAT of both strains after HFD when expressing oxidase activity per milligram of protein. However, when considering the overall capacity of the fat depots to oxidize tyramine or benzylamine, there was an increase in MAO and SSAO activity only in the enlarged WAT of HFD-induced obese mice. Therefore, the comparison of these models allowed to demonstrate that the higher amine oxidase capacity hold in enlarged fat stores of obese mice is more likely the consequence of increased fat cell number rather than the result of an increased expression of MAO or SSAO in the adipocyte.
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Affiliation(s)
- V Visentin
- Institut National de la Santé et de la Recherche Médicale, U586, IFR 31, Bat. L3, CHU Rangueil, Université Paul Sabatier, 31432 Toulouse, France
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41
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Carpéné C, Bour S, Visentin V, Pellati F, Benvenuti S, Iglesias-Osma MC, García-Barrado MJ, Valet P. Amine oxidase substrates for impaired glucose tolerance correction. J Physiol Biochem 2005; 61:405-19. [PMID: 16180339 DOI: 10.1007/bf03167058] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Amine oxidases are widely distributed from microorganisms to vertebrates and produce hydrogen peroxide plus aldehyde when catabolizing endogenous or xenobiotic amines. Novel roles have been attributed to several members of the amine oxidase families, which cannot be anymore considered as simple amine scavengers. Semicarbazide-sensitive amine oxidase (SSAO) is abundantly expressed in mammalian endothelial, smooth muscle, and fat cells, and plays a role in lymphocyte adhesion to vascular wall, arterial fiber elastic maturation, and glucose transport, respectively. This latter role was studied in detail and the perspectives of insulin-like actions of amine oxidase substrates are discussed in the present review. Independent studies have demonstrated that SSAO substrates and monoamine oxidase substrates mimic diverse insulin effects in adipocytes: glucose transport activation, lipogenesis stimulation and lipolysis inhibition. These substrates also stimulate in vitro adipogenesis. Acute in vivo administration of amine oxidase substrates improves glucose tolerance in rats, mice and rabbits, while chronic treatments with benzylamine plus vanadate exert an antihyperglycaemic effect in diabetic rats. Dietary supplementations with methylamine, benzylamine or tyramine have been proven to influence metabolic control in rodents by increasing glucose tolerance or decreasing lipid mobilisation, without noticeable changes in the plasma markers of lipid peroxidation or protein glycation, despite adverse effects on vasculature. Thus, the ingested amines are not totally metabolized at the intestinal level and can act on adipose and vascular tissues. In regard with this influence on metabolic control, more attention must be paid to the composition or supplementation in amines in foods and nutraceutics.
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Affiliation(s)
- C Carpéné
- INSERM U586, IFR 31, Bat L3, CHU Rangueil, Université P. Sabatier, BP 84225, 31342 Toulouse, France.
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42
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Brainard AM, Miller AJ, Martens JR, England SK. Maxi-K channels localize to caveolae in human myometrium: a role for an actin-channel-caveolin complex in the regulation of myometrial smooth muscle K+ current. Am J Physiol Cell Physiol 2005; 289:C49-57. [PMID: 15703204 DOI: 10.1152/ajpcell.00399.2004] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Multiple cell-signaling pathways converge to modulate large-conductance, voltage- and Ca2+-sensitive K+ channel (maxi-K channel) activity and buffer cell excitability in human myometrial smooth muscle cells (hMSMCs). Recent evidence indicates that maxi-K channel proteins can target to membrane microdomains; however, their association with other proteins within these macromolecular complexes has not been elucidated. Biochemical isolation of detergent-resistant membrane fractions from human myometrium demonstrates the presence of maxi-K channels in lipid raft microdomains, which cofractionate with caveolins. In both nonpregnant and late-pregnant myometrium, maxi-K channels associate and colocalize with caveolar scaffolding proteins caveolin-1 and caveolin-2, but not caveolin-3. Disruption of cultured hMSMC caveolar complexes by cholesterol depletion with cyclodextrin increases an iberiotoxin-sensitive K+ current. Coimmunoprecipitations have indicated that the maxi-K channel also is associated with both α- and γ-actin. Immunocytochemical analysis indicates colocalization of maxi-K channels, actin, and caveolin-1 in primary cultures of hMSMCs. Further experiments using immunoelectron microscopy have shown the proximity of both actin and the maxi-K channel within the same cell surface caveolar structures. Functionally, disruption of the actin cytoskeleton in cultured hMSMCs by cytochalasin D and latrunculin A greatly increased the open-state probability of the channel, while stabilization of actin cytoskeleton with jasplakinolide abolished the effect of latrunculin A. These data indicate that the actin cytoskeleton is involved as part of a caveolar complex in the regulation of myometrial maxi-K channel function.
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Affiliation(s)
- Adam M Brainard
- Department of Physiology and Biophysics, Carver College of Medicine, University of Iowa, 5-660 Bowen Science Bldg., Iowa City, Iowa 52242, USA
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43
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Gokturk C, Nordquist J, Sugimoto H, Forsberg-Nilsson K, Nilsson J, Oreland L. Semicarbazide-sensitive amine oxidase in transgenic mice with diabetes. Biochem Biophys Res Commun 2005; 325:1013-20. [PMID: 15541390 DOI: 10.1016/j.bbrc.2004.10.140] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Indexed: 11/20/2022]
Abstract
Semicarbazide-sensitive amine oxidase (SSAO) activity in plasma is increased in diabetes, and in particular, in diabetic patients with vascular complications. It has been speculated that SSAO is involved in the development of such complications due to the production of cytotoxic compounds. In this work, we have induced diabetes in a previously described mouse-model, overexpressing SSAO in smooth muscle cells. SSAO activity was estimated as well as expression of the endogenous mouse gene and human transgene using real-time PCR. Diabetes induced an increase in SSAO activity in serum, kidney, and adipose tissue of transgenic animals. An inverse correlation between SSAO activity and mouse SSAO mRNA levels was observed in transgenic animals with diabetes. These results further support the suggestion of a negative feedback control of the SSAO gene expression. The increased SSAO activity in diabetes is most likely dependent on post-transcriptional modifications or activation of existing inactive enzyme molecules.
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Affiliation(s)
- C Gokturk
- Section of Pharmacology, Department of Neuroscience, Uppsala University, Box 593, Biomedicum, 751 24 Uppsala, Sweden.
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44
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Sibon I, Larrieu D, el Hadri K, Mercier N, Fève B, Lacolley P, Labat C, Daret D, Bonnet J, Lamazière JMD. Semicarbazide-sensitive amine oxidase in annulo-aortic ectasia disease: relation to elastic lamellae-associated proteins. J Histochem Cytochem 2004; 52:1459-66. [PMID: 15505340 PMCID: PMC3957813 DOI: 10.1369/jhc.4a6252.2004] [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: 11/22/2022] Open
Abstract
Lysyl oxidases (Lox), which are members of the amine oxidase family, are involved in the maturation of elastic lamellae and collagen fibers. Modifications of amine oxidases in idiopathic annulo-aortic ectasia disease (IAAED) have never been investigated. Our aim was to examine the expression of several proteins that might interfere with elastic fiber organization in control (n=10) and IAAED (n=18) aortic tissues obtained at surgery. Expression of amine oxidases and semicarbazide-sensitive amine oxidase (SSAO), and cellular phenotypic markers were examined by immunohistopathology and confocal microscopy. The expression of these proteins was assessed in relation to clinical and histomorphological features of the arterial wall. In control aorta, SSAO staining was expressed along elastic lamellae, whereas in aneurysmal areas of IAAED, SSAO was markedly decreased, in association with severe disorganization of elastic lamellae. Smooth muscle myosin heavy chain was also decreased in IAAED compared with controls, indicating smooth muscle cell dedifferentiation. Multiple regression analysis showed that elastic lamellar thickness (ELT) was correlated positively with the SSAO:elastin ratio and negatively with the Lox:elastin ratio, and that the clinical features of IAAED (aneurysm, thoracic aorta diameter, and aortic insufficiency) were positively correlated with ELT but not with SSAO. The relationship between SSAO expression and ELT suggests that this amine oxidase may be involved in elastic fiber organization. However, in advanced IAAED, the deficit in SSAO expression could be secondary to the decrease and fragmentation of elastic fibers and/or to vascular smooth muscle cell dedifferentiation.
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MESH Headings
- Amine Oxidase (Copper-Containing)/biosynthesis
- Aorta, Thoracic/enzymology
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/ultrastructure
- Aortic Aneurysm, Thoracic/complications
- Aortic Aneurysm, Thoracic/enzymology
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Valve Insufficiency/complications
- Aortic Valve Insufficiency/enzymology
- Aortic Valve Insufficiency/metabolism
- Cell Differentiation
- Elastin/biosynthesis
- Extracellular Matrix/enzymology
- Extracellular Matrix/metabolism
- Extracellular Matrix/ultrastructure
- Female
- Humans
- Immunohistochemistry
- Male
- Microscopy, Confocal
- Middle Aged
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/ultrastructure
- Myosin Heavy Chains/biosynthesis
- Protein-Lysine 6-Oxidase/biosynthesis
- Regression Analysis
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Affiliation(s)
| | | | | | | | - Bruno Fève
- Pessac, France, and CNRS UMR 7079, Paris, France
| | | | | | | | | | - Jean-Marie Daniel Lamazière
- Inserm U441, Paris, France
- Correspondence to: Jean-Marie Daniel Lamazière, Inserm U441, Université Victor Segalen Bordeaux 2, avenue du Haut Lévěque, 33600 Pessac, France. E-mail:
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45
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Subra C, Fontana E, Visentin V, Testar X, Carpéné C. Tyramine and benzylamine partially but selectively mimic insulin action on adipose differentiation in 3T3-L1 cells. J Physiol Biochem 2004; 59:209-16. [PMID: 15000452 DOI: 10.1007/bf03179917] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Biogenic amines like tyramine, methylamine and the non-naturally occuring amine, benzylamine, have been described to promote adipose conversion of murine 3T3 preadipocytes. To further investigate these novel effects of amines, we studied whether they selectively mimic the long-term adipogenic action of insulin. To this aim, we decided to use the 3T3-L1 cell line since this model needs a complex combination of inducers to trigger the differentiation programme: insulin, isobutylmethylxanthine (IBMX, an activator of cAMP-signal transduction pathway) and the synthetic glucocorticoid, dexamethasone. A cell culture protocol was designed, by which each component of the differentiation cocktail was replaced with either benzylamine or tyramine, in order to determine whether these amine oxidase substrates could substitute any of the differentiation inducers in 3T3-L1 cells. The incomplete lipid accumulation found in cells grown under IBMX- or dexamethasone-free conditions was not improved by the daily addition of amines to the culture medium. Insulin was the only component of adipose differentiation cocktail of 3T3-L1 that could be replaced, although partially, by tyramine or benzylamine. When used at 0.5 mM, these amines resulted in a significant increase of triacylglycerol accumulated eight days after confluence, when compared to cells kept without insulin. This partial insulin replacement was totally abolished by SSAO-inhibitors, while MAO-blockade did not reduce lipid accumulation. As previously reported for other insulin-sensitive processes, such as stimulation of glucose transport or lipolysis inhibition in mature adipocytes, the stimulation of adipogenesis by tyramine and benzylamine was an SSAO-dependent mechanism that apparently shared common signaling pathways with insulin.
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Affiliation(s)
- C Subra
- Institut National de la Santé et de la Recherche Médicale, U586, CHU Rangueil, 31043 Toulouse, France
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46
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O'Sullivan J, Unzeta M, Healy J, O'Sullivan MI, Davey G, Tipton KF. Semicarbazide-sensitive amine oxidases: enzymes with quite a lot to do. Neurotoxicology 2004; 25:303-15. [PMID: 14697905 DOI: 10.1016/s0161-813x(03)00117-7] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The semicarbazide-sensitive amine oxidases (SSAO) (EC 1.4.3.6) were believed to be detoxifying enzymes, primarily involved in the oxidative deamination of endogenous amines, such as methylamine and aminoacetone, together with some xenobiotic amines. However, it appears that the reaction products may have important signalling functions in the regulation of cell development and glucose homeostasis. Furthermore, enzyme, from some sources, behaves as a cellular adhesion protein under inflammatory and it may also be involved in lipid transport. This review considers what is known about the activities and potential functions of this hardworking protein.
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Affiliation(s)
- Jeff O'Sullivan
- Department of Biochemistry, Trinity College, Dublin 2, Ireland
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47
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Olivé M, Unzeta M, Moreno D, Ferrer I. Overexpression of semicarbazide-sensitive amine oxidase in human myopathies. Muscle Nerve 2004; 29:261-6. [PMID: 14755492 DOI: 10.1002/mus.10550] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oxidative stress has been implicated in the pathogenesis of several muscle diseases. Semicarbazide-sensitive amine oxidase (SSAO) metabolizes oxidative deamination of primary aromatic and aliphatic amines. In the oxidative reactions, amine substrates are converted into the aldehyde, followed by the production of ammonia and H(2)O(2). Although normal levels in muscle are very low, SSAO is expressed in almost all mammalian tissues. In this study, we examined the possible implication of SSAO as an additional source of oxidative stress in the pathogenesis of muscle disorders. The expression of SSAO was examined immunohistochemically in muscle biopsy specimens from patients with inclusion-body myositis (IBM; n = 5), desmin-related myopathy (DRM; n = 3), dermatomyositis (n = 3), granulomatous (sarcoid) myopathy (n = 2), muscle denervation-reinnervation (n = 3), and rhabdomyolysis (n = 2), as well as from control subjects (n = 3). Strong SSAO immunoreactivity was present in vacuolated and nonvacuolated fibers in IBM, in abnormal fibers in DRM, and in degenerating and regenerating fibers in dermatomyositis and rhabdomyolysis. In addition, SSAO overexpression was observed in muscle fibers adjacent to granulomas in sarcoid myopathy. These results suggest that SSAO is a source of oxidative stress in diseased human skeletal muscle and that it contributes to oxidative stress-induced damage in various inflammatory and other myopathies. Alternatively, the expression of SSAO in muscle fibers may be a consequence of muscle fiber injury.
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Affiliation(s)
- Montse Olivé
- Institut de Neuropatologia, Hospital Universitari de Bellvitge, 08907 Hospitalet de Llobregat, Barcelona, Spain.
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48
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Stolen CM, Madanat R, Marti L, Kari S, Yegutkin GG, Sariola H, Zorzano A, Jalkanen S. Semicarbazide sensitive amine oxidase overexpression has dual consequences: insulin mimicry and diabetes-like complications. FASEB J 2004; 18:702-4. [PMID: 14977883 DOI: 10.1096/fj.03-0562fje] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Semicarbazide-sensitive amine oxidases (SSAO) are copper-containing enzymes that oxidatively deaminate primary amines to produce hydrogen peroxide, ammonium, and specific aldehydes. Vascular adhesion protein-1 (VAP-1) is a cell surface and soluble molecule that possesses SSAO activity. VAP-1 protein, SSAO activity, and SSAO reaction products are elevated in the serum of patients with diabetes, congestive heart failure, and specific inflammatory liver diseases. By expressing human VAP-1/SSAO on mouse endothelial cells and subsequently in the serum, and by chronically treating the transgenic mice for 15 months with a high-fat diet and a physiological substrate for SSAO, methylamine, the in vivo roles of SSAO were assessed. The VAP-1 transgene increased the mouse body mass index and subcutaneous abdominal fat pad weights in a manner independent of food consumption. The transgene together with increased SSAO substrate availability enhanced glucose uptake in an SSAO-dependent manner. The increased SSAO activity also led to diabetes-like complications, including advanced glycation end product formation, elevated blood pressure, altered atherosclerosis progression, and nephropathy. These findings suggest that, although manipulation of VAP-1/SSAO has potential to serve as a therapeutic treatment in insulin-resistant conditions, care must be taken to fully understand its impact on obesity and vascular damage.
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Affiliation(s)
- Craig M Stolen
- MediCity Research Laboratory, University of Turku and National Public Health Institute, Turku, Finland.
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49
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Göktürk C, Nilsson J, Nordquist J, Kristensson M, Svensson K, Söderberg C, Israelson M, Garpenstrand H, Sjöquist M, Oreland L, Forsberg-Nilsson K. Overexpression of semicarbazide-sensitive amine oxidase in smooth muscle cells leads to an abnormal structure of the aortic elastic laminas. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 163:1921-8. [PMID: 14578191 DOI: 10.1016/s0002-9440(10)63550-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Elevated semicarbazide-sensitive amine oxidase (SSAO) activity has been observed in several human conditions, eg, diabetes, and it has been speculated that SSAO contributes to the development of vasculopathies associated with this disease. To investigate in vivo consequences of elevated expression of SSAO in vascular tissues, we have developed a transgenic model for overexpression of human SSAO in mice. A smooth muscle-specific promoter, smooth muscle alpha-actin promoter 8 (SMP8) was used. Transgenic expression of human SSAO in tissues with a high content of smooth muscle cells was confirmed by Northern blot analysis. Enzymatic analysis of homogenates from transgenic tissues showed elevated levels of SSAO activity compared to non-transgenic littermates. Furthermore, when plasma SSAO activity was analyzed, much higher activity was detected compared to plasma from control mice, indicating that plasma SSAO may originate from smooth muscle cells. Histopathological evaluation of aorta and renal artery from transgenic mice revealed an abnormal structure of the elastin tissue. Instead of the regularly folded elastic laminae normally found in tunica media of sacrificed mice, the elastic laminae were straight and unfolded with irregularly arranged elastic fibers, forming tangled webs, between the intercalating elastic laminae. These alterations of the elastin structures suggest that overexpression of SSAO has led to a reduced elasticity of the arteries. Moreover, the mean femoral arterial pressure of the SMP8 SSAO transgenic mice was significantly lower in comparison to non-transgenic littermates. This suggests that the transgenic mice have a defect in their ability to regulate blood pressure.
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Affiliation(s)
- Camilla Göktürk
- Department of Neuroscience, Uppsala University, Biomedicum, 751-24 Uppsala, Sweden
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Yu PH, Wright S, Fan EH, Lun ZR, Gubisne-Harberle D. Physiological and pathological implications of semicarbazide-sensitive amine oxidase. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1647:193-9. [PMID: 12686132 DOI: 10.1016/s1570-9639(03)00101-8] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Semicarbazide-sensitive amine oxidase (SSAO) catalyzes the deamination of primary amines. Such deamination has been shown capable of regulating glucose transport in adipose cells. It has been independently discovered that the primary structure of vascular adhesion protein-1 (VAP-1) is identical to SSAO. VAP-1 regulates leukocyte migration and is related to inflammation. Increased serum SSAO activities have been found in patients with diabetic mellitus, vascular disorders and Alzheimer's disease. The SSAO-catalyzed deamination of endogenous substrates, that is, methylamine and aminoacetone, led to production of toxic formaldehyde and methylglyoxal, hydrogen peroxide and ammonia, respectively. These highly reactive aldehydes have been shown to initiate protein cross-linkage, exacerbate advanced glycation of proteins and cause endothelial injury. Hydrogen peroxide contributes to oxidative stress. 14C-methylamine is converted to 14C-formaldehyde, which then forms labeled long-lasting protein adduct in rodents. Chronic methylamine treatment increased the excretion of malondialdehyde and microalbuminuria, and enhanced the formation of fatty streaks in C57BL/6 mice fed with an atherogenic diet. Treatment with selective SSAO inhibitor reduces atherogenesis in KKAy diabetic mice fed with high-cholesterol diet. Aminoguanidine, which blocks advanced glycation and reduces nephropathy in animals, is in fact more potent at inhibiting SSAO than its effect on glycation. It suggests that SSAO is involved in vascular disorders under certain pathological conditions. Although SSAO has been known for several decades, its physiological and pathological implications are just beginning to be recognized.
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Affiliation(s)
- Peter H Yu
- Neuropsychiatry Research Unit, Department of Psychiatry, College of Medicine, University of Saskatchewan, A114 Medical Research Building, Saskatoon, Saskatchewan, Canada S7N 5E4.
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