1
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Chen Q, Kou M, He Y, Zhao Y, Chen L. Constructing hierarchical surface structure of hemodialysis membranes to intervene in oxidative stress through Michael addition reaction between tannic acid and PEtOx brushes. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.120700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Metabolomics profiling reveals defense strategies of Pediococcus pentosaceus R1 isolated from Harbin dry sausages under oxidative stress. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2020.110041] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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3
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Rafikova O, Meadows ML, Kinchen JM, Mohney RP, Maltepe E, Desai AA, Yuan JXJ, Garcia JGN, Fineman JR, Rafikov R, Black SM. Metabolic Changes Precede the Development of Pulmonary Hypertension in the Monocrotaline Exposed Rat Lung. PLoS One 2016; 11:e0150480. [PMID: 26937637 PMCID: PMC4777490 DOI: 10.1371/journal.pone.0150480] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/14/2016] [Indexed: 12/13/2022] Open
Abstract
There is increasing interest in the potential for metabolic profiling to evaluate the progression of pulmonary hypertension (PH). However, a detailed analysis of the metabolic changes in lungs at the early stage of PH, characterized by increased pulmonary artery pressure but prior to the development of right ventricle hypertrophy and failure, is lacking in a preclinical animal model of PH. Thus, we undertook a study using rats 14 days after exposure to monocrotaline (MCT), to determine whether we could identify early stage metabolic changes prior to the manifestation of developed PH. We observed changes in multiple pathways associated with the development of PH, including activated glycolysis, increased markers of proliferation, disruptions in carnitine homeostasis, increased inflammatory and fibrosis biomarkers, and a reduction in glutathione biosynthesis. Further, our global metabolic profile data compare favorably with prior work carried out in humans with PH. We conclude that despite the MCT-model not recapitulating all the structural changes associated with humans with advanced PH, including endothelial cell proliferation and the formation of plexiform lesions, it is very similar at a metabolic level. Thus, we suggest that despite its limitations it can still serve as a useful preclinical model for the study of PH.
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Affiliation(s)
- Olga Rafikova
- Division of Translational and Regenerative Medicine, The University of Arizona, Tucson, Arizona, United States of America
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
| | - Mary L. Meadows
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia, United States of America
| | | | | | - Emin Maltepe
- Division of Neonatology, University of California San Francisco, San Francisco, California, United States of America
| | - Ankit A. Desai
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
| | - Jason X.-J. Yuan
- Division of Translational and Regenerative Medicine, The University of Arizona, Tucson, Arizona, United States of America
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
| | - Joe G. N. Garcia
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
| | - Jeffrey R. Fineman
- Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Ruslan Rafikov
- Division of Translational and Regenerative Medicine, The University of Arizona, Tucson, Arizona, United States of America
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
| | - Stephen M. Black
- Division of Translational and Regenerative Medicine, The University of Arizona, Tucson, Arizona, United States of America
- Department of Medicine, The University of Arizona, Tucson, Arizona, United States of America
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Santhanam AVR, d’Uscio LV, He T, Das P, Younkin SG, Katusic ZS. Uncoupling of endothelial nitric oxide synthase in cerebral vasculature of Tg2576 mice. J Neurochem 2015; 134:1129-38. [PMID: 26111938 PMCID: PMC5627976 DOI: 10.1111/jnc.13205] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 06/08/2015] [Accepted: 06/19/2015] [Indexed: 11/28/2022]
Abstract
In this study, we tested the hypothesis that reduced bioavailability of tetrahydrobiopterin (BH4) is a major mechanism responsible for pathogenesis of endothelial dysfunction in cerebral microvessels of transgenic mice expressing the Swedish double mutation of human amyloid precursor protein (APP) (Tg2576 mice). Endothelial nitric oxide synthase (eNOS) protein expression was significantly increased in cerebral vasculature of Tg2576 mice. In contrast, bioavailability of BH4 was significantly reduced (p < 0.05). Moreover, superoxide anion production was increased in cerebral microvessels of Tg2576 mice (p < 0.05). Incubation with NOS inhibitor, Nω-nitro-L-arginine methyl ester, decreased superoxide anion indicating that uncoupled eNOS is most likely the source of superoxide anion. Increasing BH4 bioavailability either exogenously by BH4 supplementation or endogenously by treatment with the selective peroxisome proliferator-activated receptor--delta activator GW501516 (2 mg/kg/day, 14 days) attenuated eNOS uncoupling and decreased superoxide anion production in cerebral microvessels of Tg2576 mice (p < 0.05). Treatment with GW501516 restored the biological activity of endothelial nitric oxide in cerebral microvessels of Tg2576 mice, as indicated by the increased nitrite/nitrate content and 3,5-cyclic guanosine monophosphate levels (p < 0.05). Our studies indicate that sub-optimal BH4 bioavailability in cerebral vasculature is an important contributor to oxidant stress and endothelial dysfunction in Tg2576 mouse model of Alzheimer's disease. Existing evidence suggests that Aβ peptides-induced up-regulation of expression and activity of NADPH oxidase causes increased production of superoxide anion (.O2(-)). .O2(-) can also be converted to hydrogen peroxide (H2O2) by enzymatic activity of superoxide dismutase (SOD) or spontaneous dismutation. Elevation of .O2(-) and H2O2 might cause oxidation of tetrahydrobiopterin (BH4) to dihydrobiopterin (BH2) and subsequent uncoupling of endothelial nitric oxide synthase (eNOS) (a) thus reducing levels of nitric oxide (NO) and 3',5'-cyclic guanosine monophosphate (cGMP). Supplementation of BH4 or activation of PPARδ prevents detrimental effects of eNOS uncoupling by restoring bioavailability of BH4 and scavenging of .O2(-), respectively (b). Activation of PPARδ also increases expression of catalase thereby inactivating H2O2. Generation of H2O2 by uncoupled eNOS in cerebral microvessels of Tg2576 mice is hypothetical.
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Affiliation(s)
- Anantha Vijay R. Santhanam
- Departments of Anesthesiology, and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN
| | - Livius V. d’Uscio
- Departments of Anesthesiology, and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN
| | - Tongrong He
- Departments of Anesthesiology, and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN
| | - Pritam Das
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL
| | | | - Zvonimir S. Katusic
- Departments of Anesthesiology, and Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN
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5
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Zhong L, Wang L, Xu L, Liu Q, Jiang L, Zhi Y, Lu W, Zhou P. The role of nitric oxide synthase in an early phase Cd-induced acute cytotoxicity in MCF-7 cells. Biol Trace Elem Res 2015; 164:130-8. [PMID: 25510362 DOI: 10.1007/s12011-014-0187-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 11/17/2014] [Indexed: 11/29/2022]
Abstract
Literature to date has confirmed that cadmium (Cd) can accomplish its toxic effects via the free radical-induced damage, but Cd itself cannot generate free radicals directly. Nitric oxide (NO) is a fundamental molecule that interplays with reactive oxygen species (ROS), which may be associated with the Cd-induced cytotoxicity. However, the role of nitric oxide synthase (NOS) in an early phase Cd-induced acute cytotoxicity and its interaction has not been studied. In this report, we provide data showing that CdCl2 (10 μM, 100 μM, 1 mM) could modulate NOS activity in terms of NO production which was first suppressed with the release of Ca(2+) and Zn(2+), then induced with the transcriptional and translational activation of the three NOS isoforms in a possible feedback manner. The ROS level in cells was increased after CdCl2 exposure. By using the free radical scavenger N-acetyl-L-cysteine (LNAC) or the NOS activity inhibitor N(G)-methyl-L-arginine (LNMMA), it was demonstrated that NOS played a critical role on the Cd-induced ROS generation. The Cd-induced cytotoxicity was associated with the NOS-mediated oxidative stress in MCF-7 cells.
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Affiliation(s)
- Lingying Zhong
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China
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6
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The role of NOS-mediated ROS accumulation in an early phase Cu-induced acute cytotoxicity in MCF-7 cells. Biometals 2014; 28:113-22. [PMID: 25403658 DOI: 10.1007/s10534-014-9807-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/29/2014] [Indexed: 10/24/2022]
Abstract
Copper (Cu) ion is essential for the biological systems, however, high level of CuCl2 exposure causes detrimental effects, which leads to cell apoptosis. Nitric oxide (NO) is an efficient cell signal messenger, which plays an important role in cell apoptosis. However, the potential mechanism of an early phase Cu-induced acute cytotoxicity through the nitric oxide synthase (NOS) signaling pathway and its interaction has not been studied. In this report, we provide data showing that high level of CuCl2 could rapidly decrease the NO production with the release of Ca(2+) and Zn(2+), and then modulate the transcriptional and translational expression of NOSs in MCF-7 cells. The reactive oxygen species (ROS) level in cells was increased after high level of CuCl2 exposure, which led to the alpha subunit of eukaryotic initiation factor 2 phosphorylation. By using the free radical scavenger N-acetyl-L-cysteine or the NOS substrate L-arginine, it demonstrated that NOS played a critical role on the Cu-induced ROS generation, which further led to the oxidative stress and cell apoptosis. These results suggested that Cu-induced apoptosis was associated with the oxidative stress, and through the NOS-mediated signaling pathway.
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Rafikov R, Kumar S, Aggarwal S, Hou Y, Kangath A, Pardo D, Fineman JR, Black SM. Endothelin-1 stimulates catalase activity through the PKCδ-mediated phosphorylation of serine 167. Free Radic Biol Med 2014; 67:255-64. [PMID: 24211614 PMCID: PMC3945115 DOI: 10.1016/j.freeradbiomed.2013.10.814] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/15/2013] [Accepted: 10/17/2013] [Indexed: 01/03/2023]
Abstract
Our previous studies have shown that endothelin-1 (ET-1) stimulates catalase activity in endothelial cells and in lambs with acute increases in pulmonary blood flow (PBF), without altering gene expression. The purpose of this study was to investigate the molecular mechanism by which this occurs. Exposing pulmonary arterial endothelial cells to ET-1 increased catalase activity and decreased cellular hydrogen peroxide (H2O2) levels. These changes correlated with an increase in serine-phosphorylated catalase. Using the inhibitory peptide δV1.1, this phosphorylation was shown to be protein kinase Cδ (PKCδ) dependent. Mass spectrometry identified serine 167 as the phosphorylation site. Site-directed mutagenesis was used to generate a phospho-mimic (S167D) catalase. Activity assays using recombinant protein purified from Escherichia coli or transiently transfected COS-7 cells demonstrated that S167D catalase had an increased ability to degrade H2O2 compared to the wild-type enzyme. Using a phospho-specific antibody, we were able to verify that pS167 catalase levels are modulated in lambs with acute increases in PBF in the presence and absence of the ET receptor antagonist tezosentan. S167 is located on the dimeric interface, suggesting it could be involved in regulating the formation of catalase tetramers. To evaluate this possibility we utilized analytical gel filtration to examine the multimeric structure of recombinant wild-type and S167D catalase. We found that recombinant wild-type catalase was present as a mixture of monomers and dimers, whereas S167D catalase was primarily tetrameric. Further, the incubation of wild-type catalase with PKCδ was sufficient to convert wild-type catalase into a tetrameric structure. In conclusion, this is the first report indicating that the phosphorylation of catalase regulates its multimeric structure and activity.
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Affiliation(s)
- Ruslan Rafikov
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
- Please address correspondence and proofs to: Stephen M. Black, Ph.D., Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Blvd, CB 3211-B, Augusta, GA-30912, Tel: 706-721-7860,
| | - Sanjiv Kumar
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
- Please address correspondence and proofs to: Stephen M. Black, Ph.D., Vascular Biology Center, Georgia Regents University, 1459 Laney Walker Blvd, CB 3211-B, Augusta, GA-30912, Tel: 706-721-7860,
| | - Saurabh Aggarwal
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
| | - Yali Hou
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
| | - Archana Kangath
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
| | - Daniel Pardo
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
| | - Jeffrey R. Fineman
- Department of Pediatrics University of California, San Francisco, CA, 94143
- Cardiovascular Research Institute, University of California, San Francisco, CA, 94143
| | - Stephen M. Black
- Pulmonary Disease Program, Vascular Biology Center, Georgia Regents University, Augusta GA 30912
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8
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Rafikov R, Kumar S, Aggarwal S, Pardo D, Fonseca FV, Ransom J, Rafikova O, Chen Q, Springer ML, Black SM. Protein engineering to develop a redox insensitive endothelial nitric oxide synthase. Redox Biol 2014; 2:156-64. [PMID: 25460726 PMCID: PMC4297941 DOI: 10.1016/j.redox.2013.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/25/2022] Open
Abstract
The zinc tetrathiolate (ZnS4) cluster is an important structural feature of endothelial nitric oxide synthase (eNOS). The cluster is located on the dimeric interface and four cysteine residues (C94 and C99 from two adjacent subunits) form a cluster with a Zn ion in the center of a tetrahedral configuration. Due to its high sensitivity to oxidants this cluster is responsible for eNOS dimer destabilization during periods of redox stress. In this work we utilized site directed mutagenesis to replace the redox sensitive cysteine residues in the ZnS4 cluster with redox stable tetra-arginines. Our data indicate that this C94R/C99R eNOS mutant is active. In addition, this mutant protein is insensitive to dimer disruption and inhibition when challenged with hydrogen peroxide (H2O2). Further, the overexpression of the C94R/C99R mutant preserved the angiogenic response in endothelial cells challenged with H2O2. The over-expression of the C94R/C99R mutant preserved the ability of endothelial cells to migrate towards vascular endothelial growth factor (VEGF) and preserved the endothelial monolayer in a scratch wound assay. We propose that this dimer stable eNOS mutant could be utilized in the treatment of diseases in which there is eNOS dysfunction due to high levels of oxidative stress. The ZnS4 cluster is an important structural feature of eNOS. This cluster is responsible for eNOS dimer destabilization during redox stress. Site directed mutagenesis replaced ZnS4 clusters with redox stable tetra-arginines. This eNOS mutant is insensitive to dimer disruption during redox stress. This eNOS mutant continues to produce NO during redox stress.
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Affiliation(s)
- Ruslan Rafikov
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Sanjiv Kumar
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Saurabh Aggarwal
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Daniel Pardo
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Fabio V Fonseca
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Jessica Ransom
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Olga Rafikova
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA
| | - Qiumei Chen
- The Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Matthew L Springer
- The Division of Cardiology, University of California, San Francisco, San Francisco, CA, USA
| | - Stephen M Black
- Pulmonary Vascular Disease, Vascular Biology Center, Georgia Regents University, Augusta, GA, USA.
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9
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Aggarwal S, Gross CM, Sharma S, Fineman JR, Black SM. Reactive oxygen species in pulmonary vascular remodeling. Compr Physiol 2013; 3:1011-34. [PMID: 23897679 DOI: 10.1002/cphy.c120024] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The pathogenesis of pulmonary hypertension is a complex multifactorial process that involves the remodeling of pulmonary arteries. This remodeling process encompasses concentric medial thickening of small arterioles, neomuscularization of previously nonmuscular capillary-like vessels, and structural wall changes in larger pulmonary arteries. The pulmonary arterial muscularization is characterized by vascular smooth muscle cell hyperplasia and hypertrophy. In addition, in uncontrolled pulmonary hypertension, the clonal expansion of apoptosis-resistant endothelial cells leads to the formation of plexiform lesions. Based upon a large number of studies in animal models, the three major stimuli that drive the vascular remodeling process are inflammation, shear stress, and hypoxia. Although, the precise mechanisms by which these stimuli impair pulmonary vascular function and structure are unknown, reactive oxygen species (ROS)-mediated oxidative damage appears to play an important role. ROS are highly reactive due to their unpaired valence shell electron. Oxidative damage occurs when the production of ROS exceeds the quenching capacity of the antioxidant mechanisms of the cell. ROS can be produced from complexes in the cell membrane (nicotinamide adenine dinucleotide phosphate-oxidase), cellular organelles (peroxisomes and mitochondria), and in the cytoplasm (xanthine oxidase). Furthermore, low levels of tetrahydrobiopterin (BH4) and L-arginine the rate limiting cofactor and substrate for endothelial nitric oxide synthase (eNOS), can cause the uncoupling of eNOS, resulting in decreased NO production and increased ROS production. This review will focus on the ROS generation systems, scavenger antioxidants, and oxidative stress associated alterations in vascular remodeling in pulmonary hypertension.
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Affiliation(s)
- Saurabh Aggarwal
- Pulmonary Disease Program, Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia, USA
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10
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Wende AR, Symons JD, Abel ED. Mechanisms of lipotoxicity in the cardiovascular system. Curr Hypertens Rep 2013; 14:517-31. [PMID: 23054891 DOI: 10.1007/s11906-012-0307-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cardiovascular diseases account for approximately one third of all deaths globally. Obese and diabetic patients have a high likelihood of dying from complications associated with cardiovascular dysfunction. Obesity and diabetes increase circulating lipids that upon tissue uptake, may be stored as triglyceride, or may be metabolized in other pathways, leading to the generation of toxic intermediates. Excess lipid utilization or activation of signaling pathways by lipid metabolites may disrupt cellular homeostasis and contribute to cell death, defining the concept of lipotoxicity. Lipotoxicity occurs in multiple organs, including cardiac and vascular tissues, and a number of specific mechanisms have been proposed to explain lipotoxic tissue injury. In addition, recent data suggests that increased tissue lipids may also be protective in certain contexts. This review will highlight recent progress toward elucidating the relationship between nutrient oversupply, lipotoxicity, and cardiovascular dysfunction. The review will focus in two sections on the vasculature and cardiomyocytes respectively.
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Affiliation(s)
- Adam R Wende
- Program in Molecular Medicine, Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, 84112, USA
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11
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Symons JD, Abel ED. Lipotoxicity contributes to endothelial dysfunction: a focus on the contribution from ceramide. Rev Endocr Metab Disord 2013; 14:59-68. [PMID: 23292334 PMCID: PMC4180664 DOI: 10.1007/s11154-012-9235-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cardiovascular complications are the leading causes of morbidity and mortality in individuals with obesity, type 2 diabetes mellitus (T2DM), and insulin resistance. Complications include pathologies specific to large (atherosclerosis, cardiomyopathy) and small (retinopathy, nephropathy, neuropathy) vessels. Common among all of these pathologies is an altered endothelial cell phenotype i.e., endothelial dysfunction. A crucial aspect of endothelial dysfunction is reduced nitric oxide (NO) bioavailability. Hyperglycemia, oxidative stress, activation of the renin-angiotensin system, and increased pro-inflammatory cytokines are systemic disturbances in individuals with obesity, T2DM, and insulin resistance and each of these contribute independently and synergistically to decreasing NO bioavailability. This review will examine the contribution from elevated circulating fatty acids in these subjects that lead to lipotoxicity. Particular focus will be placed on the fatty acid metabolite ceramide.
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Affiliation(s)
- J David Symons
- College of Health, University of Utah, School of Medicine, Salt Lake City, UT, USA.
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12
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Zhang QJ, Holland WL, Wilson L, Tanner JM, Kearns D, Cahoon JM, Pettey D, Losee J, Duncan B, Gale D, Kowalski CA, Deeter N, Nichols A, Deesing M, Arrant C, Ruan T, Boehme C, McCamey DR, Rou J, Ambal K, Narra KK, Summers SA, Abel ED, Symons JD. Ceramide mediates vascular dysfunction in diet-induced obesity by PP2A-mediated dephosphorylation of the eNOS-Akt complex. Diabetes 2012; 61:1848-59. [PMID: 22586587 PMCID: PMC3379648 DOI: 10.2337/db11-1399] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vascular dysfunction that accompanies obesity and insulin resistance may be mediated by lipid metabolites. We sought to determine if vascular ceramide leads to arterial dysfunction and to elucidate the underlying mechanisms. Pharmacological inhibition of de novo ceramide synthesis, using the Ser palmitoyl transferase inhibitor myriocin, and heterozygous deletion of dihydroceramide desaturase prevented vascular dysfunction and hypertension in mice after high-fat feeding. These findings were recapitulated in isolated arteries in vitro, confirming that ceramide impairs endothelium-dependent vasorelaxation in a tissue-autonomous manner. Studies in endothelial cells reveal that de novo ceramide biosynthesis induced protein phosphatase 2A (PP2A) association directly with the endothelial nitric oxide synthase (eNOS)/Akt/Hsp90 complex that was concurrent with decreased basal and agonist-stimulated eNOS phosphorylation. PP2A attenuates eNOS phosphorylation by preventing phosphorylation of the pool of Akt that colocalizes with eNOS and by dephosphorylating eNOS. Ceramide decreased the association between PP2A and the predominantly cytosolic inhibitor 2 of PP2A. We conclude that ceramide mediates obesity-related vascular dysfunction by a mechanism that involves PP2A-mediated disruption of the eNOS/Akt/Hsp90 signaling complex. These results provide important insight into a pathway that represents a novel target for reversing obesity-related vascular dysfunction.
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Affiliation(s)
- Quan-Jiang Zhang
- College of Health, University of Utah, Salt Lake City, Utah
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, Utah
- Program in Molecular Medicine, University of Utah, Salt Lake City, Utah
| | - William L. Holland
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Lloyd Wilson
- College of Health, University of Utah, Salt Lake City, Utah
| | | | - Devin Kearns
- College of Health, University of Utah, Salt Lake City, Utah
| | - Judd M. Cahoon
- College of Health, University of Utah, Salt Lake City, Utah
| | - Dix Pettey
- College of Health, University of Utah, Salt Lake City, Utah
| | - Jason Losee
- College of Health, University of Utah, Salt Lake City, Utah
| | - Bradlee Duncan
- College of Health, University of Utah, Salt Lake City, Utah
| | - Derrick Gale
- College of Health, University of Utah, Salt Lake City, Utah
| | | | | | | | | | - Colton Arrant
- College of Health, University of Utah, Salt Lake City, Utah
| | - Ting Ruan
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, Utah
| | - Christoph Boehme
- Department of Physics and Astronomy, College of Science, University of Utah, Salt Lake City, Utah
| | - Dane R. McCamey
- Department of Physics and Astronomy, College of Science, University of Utah, Salt Lake City, Utah
| | - Janvida Rou
- Department of Physics and Astronomy, College of Science, University of Utah, Salt Lake City, Utah
| | - Kapil Ambal
- Department of Physics and Astronomy, College of Science, University of Utah, Salt Lake City, Utah
| | - Krishna K. Narra
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, Utah
| | - Scott A. Summers
- Program in Cardiovascular and Metabolic Diseases, Duke-NUS Graduate Medical School, Singapore, and the Stedman Center for Nutrition and Metabolism Research, Duke University Medical Center, Durham, North Carolina
| | - E. Dale Abel
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, Utah
- Program in Molecular Medicine, University of Utah, Salt Lake City, Utah
- Corresponding authors: E. Dale Abel, , and J. David Symons,
| | - J. David Symons
- College of Health, University of Utah, Salt Lake City, Utah
- Division of Endocrinology, Metabolism, and Diabetes, University of Utah School of Medicine, Salt Lake City, Utah
- Corresponding authors: E. Dale Abel, , and J. David Symons,
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