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Patel R, Kumar S, Varghese JF, Singh N, Singh RP, Yadav UCS. Silymarin prevents endothelial dysfunction by upregulating Erk-5 in oxidized LDL exposed endothelial cells. Microvasc Res 2024; 153:104667. [PMID: 38307406 DOI: 10.1016/j.mvr.2024.104667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/12/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
Extracellular signal-regulated kinase (Erk)-5 is a key mediator of endothelial cell homeostasis, and its inhibition causes loss of critical endothelial markers leading to endothelial dysfunction (ED). Circulating oxidized low-density lipoprotein (oxLDL) has been identified as an underlying cause of ED and atherosclerosis in metabolic disorders. Silymarin (Sym), a flavonolignan, possesses various pharmacological activities however its preventive mechanism in ED warrants further investigation. Here, we have examined the effects of Sym in regulating the expression of Erk-5 and ameliorating ED using in vitro and in vivo models. Primary human umbilical vein endothelial cells (pHUVECs) viability was measured by MTT assay; mRNA and protein expression by RT-qPCR and Western blotting; tube-formation assay was performed to examine endothelialness. In in-vivo experiments, normal chow-fed mice (control) or high-fat diet (HFD)-fed mice were administered Sym or Erk-5 inhibitor (BIX02189) and body weight, blood glucose, plasma-LDL, oxLDL levels, and expression of EC markers in the aorta were examined. Sym (5 μg/ml) maintained the viability and tube-formation ability of oxLDL exposed pHUVECs. Sym increased the expression of Erk-5, vWF, and eNOS and decreased ICAM-1 at transcription and translation levels in oxLDL-exposed pHUVECs. In HFD-fed mice, Sym reduced the body weight, blood glucose, LDL-cholesterol, and oxLDL levels, and increased the levels of vWF and eNOS along with Erk-5 and decreased the level of ICAM-1 in the aorta. These data suggest that Sym could be a potent anti-atherosclerotic agent that could elevate Erk-5 level in the ECs and prevent ED caused by oxidized LDL during HFD-induced obesity in mice.
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Affiliation(s)
- Rohit Patel
- Metabolic Disorders and Inflammatory Pathologies Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat 382030, India; Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sanjay Kumar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Johnna F Varghese
- Metabolic Disorders and Inflammatory Pathologies Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat 382030, India; Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Navneendra Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India; Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard University, New Delhi 110062, India
| | - Rana P Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Umesh C S Yadav
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India.
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2
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Watso JC, Fancher IS, Gomez DH, Hutchison ZJ, Gutiérrez OM, Robinson AT. The damaging duo: Obesity and excess dietary salt contribute to hypertension and cardiovascular disease. Obes Rev 2023; 24:e13589. [PMID: 37336641 PMCID: PMC10406397 DOI: 10.1111/obr.13589] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/08/2023] [Accepted: 05/24/2023] [Indexed: 06/21/2023]
Abstract
Hypertension is a primary risk factor for cardiovascular disease. Cardiovascular disease is the leading cause of death among adults worldwide. In this review, we focus on two of the most critical public health challenges that contribute to hypertension-obesity and excess dietary sodium from salt (i.e., sodium chloride). While the independent effects of these factors have been studied extensively, the interplay of obesity and excess salt overconsumption is not well understood. Here, we discuss both the independent and combined effects of excess obesity and dietary salt given their contributions to vascular dysfunction, autonomic cardiovascular dysregulation, kidney dysfunction, and insulin resistance. We discuss the role of ultra-processed foods-accounting for nearly 60% of energy intake in America-as a major contributor to both obesity and salt overconsumption. We highlight the influence of obesity on elevated blood pressure in the presence of a high-salt diet (i.e., salt sensitivity). Throughout the review, we highlight critical gaps in knowledge that should be filled to inform us of the prevention, management, treatment, and mitigation strategies for addressing these public health challenges.
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Affiliation(s)
- Joseph C. Watso
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, USA
| | - Ibra S. Fancher
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, USA
| | - Dulce H. Gomez
- School of Kinesiology, Auburn University, Auburn, Alabama, USA
- Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | | | - Orlando M. Gutiérrez
- Division of Nephrology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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3
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Rudnicki M, Pislaru A, Rezvan O, Rullman E, Fawzy A, Nwadozi E, Roudier E, Gustafsson T, Haas TL. Transcriptomic profiling reveals sex-specific molecular signatures of adipose endothelial cells under obesogenic conditions. iScience 2022; 26:105811. [PMID: 36624843 PMCID: PMC9823135 DOI: 10.1016/j.isci.2022.105811] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/13/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Female mice display greater adipose angiogenesis and maintain healthier adipose tissue than do males upon high-fat diet feeding. Through transcriptome analysis of endothelial cells (EC) from the white adipose tissue of male and female mice high-fat-fed for 7 weeks, we found that adipose EC exhibited pronouncedly sex-distinct transcriptomes. Genes upregulated in female adipose EC were associated with proliferation, oxidative phosphorylation, and chromatin remodeling contrasting the dominant enrichment for genes related to inflammation and a senescence-associated secretory of male EC. Similar sex-biased phenotypes of adipose EC were detectable in a dataset of aged EC. The highly proliferative phenotype of female EC was observed also in culture conditions. In turn, male EC displayed greater inflammatory potential than female EC in culture, based on basal and tumor necrosis factor alpha-stimulated patterns of gene expression. Our study provides insights into molecular programs that distinguish male and female EC responses to pathophysiological conditions.
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Affiliation(s)
- Martina Rudnicki
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada,Corresponding author
| | | | - Omid Rezvan
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada
| | - Eric Rullman
- Department Laboratory Medicine, Clinical Physiology, Karolinska Institutet and Department Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Aly Fawzy
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada
| | - Emmanuel Nwadozi
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada
| | - Emilie Roudier
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada
| | - Thomas Gustafsson
- Department Laboratory Medicine, Clinical Physiology, Karolinska Institutet and Department Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - Tara L. Haas
- School of Kinesiology and Health Science & Muscle Health Research Centre, York University, Toronto, Canada,Department of Biology, York University, Toronto, Canada,Corresponding author
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4
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Tikhonova IV, Grinevich AA, Tankanag AV, Safronova VG. Skin Microhemodynamics and Mechanisms of Its Regulation in Type 2 Diabetes Mellitus. Biophysics (Nagoya-shi) 2022; 67:647-659. [PMID: 36281313 PMCID: PMC9581453 DOI: 10.1134/s0006350922040200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/19/2022] [Accepted: 05/20/2022] [Indexed: 11/07/2022] Open
Abstract
The review presents modern ideas about peripheral microhemodynamics, approaches to the ana-lysis of skin blood flow oscillations and their diagnostic significance. Disorders of skin microhemodynamics in type 2 diabetes mellitus (DM) and the possibility of their interpretation from the standpoint of external and internal interactions between systems of skin blood flow regulation, based on a comparison of couplings in normal and pathological conditions, including models of pathologies on animals, are considered. The factors and mechanisms of vasomotor regulation, among them receptors and signaling events in endothelial and smooth muscle cells considered as models of microvessels are discussed. Attention was drawn to the disturbance of Ca2+-dependent regulation of coupling between vascular cells and NO-dependent regulation of vasodilation in diabetes mellitus. The main mechanisms of insulin resistance in type 2 DM are considered to be a defect in the number of insulin receptors and impaired signal transduction from the receptor to phosphatidylinositol-3-kinase and downstream targets. Reactive oxygen species plays an important role in vascular dysfunction in hyperglycemia. It is assumed that the considered molecular and cellular mechanisms of microhemodynamics regulation are involved in the formation of skin blood flow oscillations. Parameters of skin blood microcirculation can be used as diagnostic and prognostic markers for assessing the state of the body.
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Affiliation(s)
- I. V. Tikhonova
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow oblast Russia
| | - A. A. Grinevich
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow oblast Russia
| | - A. V. Tankanag
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow oblast Russia
| | - V. G. Safronova
- Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow oblast Russia
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Time-Restricted Feeding Improved Vascular Endothelial Function in a High-Fat Diet-Induced Obesity Rat Model. Vet Sci 2022; 9:vetsci9050217. [PMID: 35622745 PMCID: PMC9147025 DOI: 10.3390/vetsci9050217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/24/2022] [Accepted: 04/25/2022] [Indexed: 11/28/2022] Open
Abstract
Obesity, where there is enhancement of stored body fat in adipose tissues, is associated with cardiovascular complications that are mainly related to atherosclerosis. Time-restricted feeding (TRF) is a form of restricted eating aimed at reducing weight in obese subjects. The present study aims to investigate changes in vascular endothelial function, endothelial nitric oxide synthase (eNOS), and protein kinase B (Akt) protein expressions with TRF in obese and normal rats. Male Sprague Dawley rats were divided into two normal and three obese groups; obesity was induced in the obese groups by feeding with a high-fat diet (HFD) for six weeks. After six weeks, rats were equally divided into five groups (n = 7 per group): Normal group (NR) which continued on a standard diet for six more weeks, normal group switched to TRF with a standard diet for six weeks (NR + TRFSD), obese group (OR) which continued on HFD for six more weeks, obese group switched to TRF of HFD (OR + TRFHFD), and obese group switched to TRF of a standard diet (OR + TRFSD). TRF was practiced for six weeks, after which the rats were sacrificed. Aortic endothelium-dependent and endothelium-independent relaxations and contractions were assessed using the organ bath. Aortic eNOS and Akt protein expressions were determined using immunoblotting. Fasting blood glucose, body weight, body mass index (BMI), serum lipid profile, Lee’s index, serum insulin levels, and sensitivity (HOMA-IR) were also measured. Endothelium-dependent relaxation was significantly impaired, while endothelium-dependent contraction increased in obese rats compared to that in normal rats. Both obese groups which underwent TRF with a HFD and standard diet improved their impairments in endothelium-dependent relaxation and reduced endothelium-dependent contraction; these were associated with increased expressions of aortic eNOS and Akt protein. Both obese groups with TRF reduced body weight, BMI, Lee’s index, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and improved insulin sensitivity. TRF improved endothelium-dependent relaxation and reduced endothelium-dependent contraction, thus attenuating endothelial dysfunction in obese rats. These were associated with increased aortic eNOS and Akt protein expressions.
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Stafeev I, Boldyreva M, Michurina S, Mamontova E, Ratner E, Menshikov M, Parfyonova Y. Grain-Based Dietary Background Impairs Restoration of Blood Flow and Skeletal Muscle During Hindlimb Ischemia in Comparison With Low-Fat and High-Fat Diets. Front Nutr 2022; 8:809732. [PMID: 35083264 PMCID: PMC8784406 DOI: 10.3389/fnut.2021.809732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/09/2021] [Indexed: 11/28/2022] Open
Abstract
Background: Among vascular pathologies associated with obesity, peripheral artery disease (PAD) occupies the important position. In clinical practice, nutritional interventions are recommended for patients with PAD. In this work, we investigated how the different dietary backgrounds affect the regeneration rate of ischemic hindlimb in mice. Methods: Male C57BL/6J mice were housed on three types of diet: low-fat (LFD), high-fat (HFD), and grain-based diet (GBD) for 13 weeks. Metabolic parameters including FBG level, ITT, and GTT were evaluated. The blood flow was assessed by laser Doppler scanning on 7, 14, and 21 days after hindlimb ischemia. Necrotic area of m.tibialis, macrophage infiltration, and angiogenesis/arteriogenesis were evaluated by histology. Glucose uptake in recovered skeletal muscle was analyzed using [3H]-2-deoxyglucose, and GLUT1 and GLUT4 expression were assessed by Western blotting. Results: In our work, we developed three experimental groups with different metabolic parameters: LFD with normal glucose metabolism, GBD with mild hyperglycemia, and HFD with impaired glucose tolerance. GBD-fed mice had a tendency to increase necrosis of m. tibialis and significantly higher macrophage infiltration than LFD and HFD groups. Moreover, GBD-fed mice had a trend to decreased blood flow recovery and significantly impaired arteriogenesis. Recovered skeletal muscle of GBD-fed mice had lower glucose uptake and decreased level of GLUT4 expression. Conclusion: Thus, we conclude that dietary background and metabolic status determine the rate of post-ischemic regeneration including angiogenesis, skeletal muscle recovery and metabolic activity. The most effective regeneration is supported by LFD, while the lowest rate of regeneration occurs on GBD.
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Affiliation(s)
- Iurii Stafeev
- National Medical Research Center for Cardiology, Moscow, Russia
| | - Maria Boldyreva
- National Medical Research Center for Cardiology, Moscow, Russia.,Faculty of Biology and Biotechnology, National Research University Higher School of Economics, Moscow, Russia
| | - Svetlana Michurina
- National Medical Research Center for Cardiology, Moscow, Russia.,Lomonosov Moscow State University, Moscow, Russia
| | - Elizaveta Mamontova
- National Medical Research Center for Cardiology, Moscow, Russia.,Lomonosov Moscow State University, Moscow, Russia
| | | | | | - Yelena Parfyonova
- National Medical Research Center for Cardiology, Moscow, Russia.,Lomonosov Moscow State University, Moscow, Russia
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7
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Radwan E, Belmadani S, Matrougui K. Disrupting Interleukin 12 Improves Microvascular Endothelial Function in Type 2 Diabetes Through ER Stress CHOP and Oxidative Stress Mechanisms. Diabetes Metab Syndr Obes 2022; 15:2633-2642. [PMID: 36065460 PMCID: PMC9440700 DOI: 10.2147/dmso.s369488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/08/2022] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Vascular endothelial dysfunction is well established in type 2 diabetes. Interleukin-12 (IL-12) and endoplasmic reticulum (ER) stress are up-regulated in type 2 diabetic patients and animal models of type 2 diabetes. However, the role and underlying mechanisms of IL-12 and the ER stress CHOP in endothelial dysfunction are not fully understood. METHODS We generated double knockout mice between db-/db- and p40IL-12-/- mice (db-/db-p40-IL-12-/-) and endoplasmic (ER) stress-CHOP-/- mice (db-/db-CHOP-/-). We performed a glucose tolerance test (GTT) to determine the effect of IL-12 and ER stress CHOP on glucose metabolism. We assessed the endothelial function and determined the phosphorylation level of eNOS, Akt, AMPK, and the expression of ER stress (CHOP, BIP), and oxidative stress (Nox2 and Nox4 and NADPH oxidase activity). RESULTS The results showed that GTT was improved in db-/db-p40-IL-12-/- and db-/db-CHOP-/- suggesting IL-12 and CHOP as parts of a mechanism involved in the development of type 2 diabetes. The microvascular endothelial dysfunction in db-/db- mouse is associated with decreased phosphorylated eNOS, Akt, AMPK, and increased CHOP, BIP, Nox2, and Nox4 expressions. Interestingly, disrupting IL-12 and ER stress CHOP in db-/db- mice significantly improved endothelial function, increased survival markers expression and decreased ER and oxidative stress. CONCLUSION Using a genetic approach, these findings provide evidence that IL-12 and ER stress CHOP play a significant role in microvascular endothelial dysfunction in type 2 diabetes.
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Affiliation(s)
- Eman Radwan
- Department of Physiological Sciences, EVMS, Norfolk, VA, 23501, USA
- Department of Medical Biochemistry, Faculty of Medicine, Assiut University, Asyut, Egypt
| | - Souad Belmadani
- Department of Physiological Sciences, EVMS, Norfolk, VA, 23501, USA
| | - Khalid Matrougui
- Department of Physiological Sciences, EVMS, Norfolk, VA, 23501, USA
- Correspondence: Khalid Matrougui, Department of Physiological Sciences, EVMS, Norfolk, VA, 23501, USA, Tel +1 757-446-5278, Email
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8
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Cutaneous innervation in impaired diabetic wound healing. Transl Res 2021; 236:87-108. [PMID: 34029747 PMCID: PMC8380642 DOI: 10.1016/j.trsl.2021.05.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/09/2021] [Accepted: 05/11/2021] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is associated with several potential comorbidities, among them impaired wound healing, chronic ulcerations, and the requirement for lower extremity amputation. Disease-associated abnormal cellular responses, infection, immunological and microvascular dysfunction, and peripheral neuropathy are implicated in the pathogenesis of the wound healing impairment and the diabetic foot ulcer. The skin houses a dense network of sensory nerve afferents and nerve-derived modulators, which communicate with epidermal keratinocytes and dermal fibroblasts bidirectionally to effect normal wound healing after trauma. However, the mechanisms through which cutaneous innervation modulates wound healing are poorly understood, especially in humans. Better understanding of these mechanisms may provide the basis for targeted treatments for chronic diabetic wounds. This review provides an overview of wound healing pathophysiology with a focus on neural involvement in normal and diabetic wound healing, as well as future therapeutic perspectives to address the unmet needs of diabetic patients with chronic wounds.
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Lakshmanan AP, Shatat IF, Zaidan S, Jacob S, Bangarusamy DK, Al-Abduljabbar S, Al-Khalaf F, Petroviski G, Terranegra A. Bifidobacterium reduction is associated with high blood pressure in children with type 1 diabetes mellitus. Biomed Pharmacother 2021; 140:111736. [PMID: 34034069 DOI: 10.1016/j.biopha.2021.111736] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/04/2021] [Accepted: 05/11/2021] [Indexed: 12/15/2022] Open
Abstract
Children with Type 1 diabetes mellitus (T1DM) have an elevated risk of abnormal blood pressure (BP) measurements and patterns. Both hypertension and T1DM are well-known risk factors for cardiovascular disease and kidney failure. The human microbiome has been linked to both diabetes and hypertension, but the relationship between the gut microbiome and BP in children with T1DM is not well-understood. In this cross-sectional study, we examined the relationship between resting office BP and gut microbiota composition, diversity, and richness in children with T1DM and healthy controls. We recruited 29 pediatric subjects and divided them into three groups: healthy controls (HC, n = 5), T1DM with normal BP (T1DM-Normo, n = 17), and T1DM with elevated BP (T1DM-HBP, n = 7). We measured the BP, dietary and clinical parameters for each subject. We collected fecal samples to perform the 16s rDNA sequencing and to measure the short-chain fatty acids (SCFAs) level. The microbiome downstream analysis included the relative abundance of microbiota, alpha and beta diversity, microbial markers using Linear Discriminant effect size analysis (LEfSe), potential gut microbial metabolic pathways using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and metabolic pathways validation using Statistical Inference of Associations between Microbial Communities And host phenotype (SIAMCAT) machine learning toolbox. Our study results showed that T1DM-HBP group had distinct gut microbial composition (at multiple taxonomic levels) and reduced diversity (richness and abundance) compared with T1DM-Normo and HC groups. Children with T1DM-HBP showed a significant reduction of Bifidobacterium levels (especially B. adolescentis, B. bifidum, and B. longum) compared to the T1DM-Normo group. We also observed unique gut-microbial metabolic pathways, such as elevated lipopolysaccharide synthesis and glutathione metabolism in children with T1DM-HBP compared to T1DM-Normo children. We can conclude that the reduction in the abundance of genus Bifidobacterium could play a significant role in elevating the BP in pediatric T1DM subjects. More studies are needed to corroborate our findings and further explore the potential contributing mechanisms we describe.
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Affiliation(s)
| | - Ibrahim F Shatat
- Pediatric Nephrology and Hypertension, Sidra Medicine, HB. 7A. 106A, P.O. Box 26999, Doha, Qatar; Weill Cornell College of Medicine-Qatar, Ar-Rayyan, Doha, Qatar; Medical University of South Carolina, Charleston, SC, USA
| | - Sara Zaidan
- Research Department, Sidra Medicine, OPC, P.O. Box 26999, Doha, Qatar
| | - Shana Jacob
- Research Department, Sidra Medicine, OPC, P.O. Box 26999, Doha, Qatar
| | | | | | - Fawziya Al-Khalaf
- Pediatric Endocrinology, Sidra Medicine, OPC, P.O. Box 26999, Doha, Qatar
| | - Goran Petroviski
- Pediatric Endocrinology, Sidra Medicine, OPC, P.O. Box 26999, Doha, Qatar
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Abstract
Obesity is epidemiologically linked to 13 forms of cancer. The local and systemic obese environment is complex and likely affect tumors through multiple avenues. This includes modulation of cancer cell phenotypes and the composition of the tumor microenvironment. A molecular understanding of how obesity links to cancer holds promise for identifying candidate genes for targeted therapy for obese cancer patient. Herein, we review both the cell-autonomous and non-cell-autonomous mechanisms linking obesity and cancer as well as provide an overview of the mouse model systems applied to study this.
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Affiliation(s)
- Xiao-Zheng Liu
- Department of Biomedicine, University of Bergen, N-5020 Bergen, Norway
| | - Line Pedersen
- Department of Biomedicine, University of Bergen, N-5020 Bergen, Norway
| | - Nils Halberg
- Department of Biomedicine, University of Bergen, N-5020 Bergen, Norway
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11
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20-HETE interferes with insulin signaling and contributes to obesity-driven insulin resistance. Prostaglandins Other Lipid Mediat 2020; 152:106485. [PMID: 33011364 DOI: 10.1016/j.prostaglandins.2020.106485] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 12/15/2022]
Abstract
20-HETE, a metabolite of arachidonic acid produced by Cytochrome P450 (CYP) 4A/4 F, has been implicated in the development of obesity-associated complications such as diabetes and insulin resistance. In this study, we examined whether the acute elevation of 20-HETE levels contributes to the development of diet-driven hyperglycemia and insulin resistance. We employed a conditional transgenic mouse model to overexpress Cyp4a12 (Cyp4a12tg), a murine 20-HETE synthase, together with high fat diet (HFD) feeding. Mice in which Cyp4a12 was induced by doxycycline (DOX) at the onset of HFD feeding gained weight at a greater rate and extent than corresponding DOX-untreated Cyp4a12 mice. Cyp4a12tg mice fed HFD + DOX displayed hyperglycemia and impaired glucose metabolism while corresponding HFD-fed Cyp4a12tg mice (no DOX) did not. Importantly, administration of a 20-HETE antagonist, 20-SOLA, to Cyp4a12tg mice fed HFD + DOX significantly attenuated weight gain and prevented the development of hyperglycemia and impaired glucose metabolism. Levels of insulin receptor (IR) phosphorylation at Tyrosine 972 and insulin receptor substrate-1 (IRS1) phosphorylation at serine 307 were markedly decreased and increased, respectively, in liver, skeletal muscle and adipose tissues from Cyp4a12tg mice fed HFD + DOX; 20-SOLA prevented the IR and IRS1 inactivation, suggesting that 20-HETE interferes with insulin signaling. Additional studies in 3T3-1 differentiated adipocytes confirmed that 20-HETE impairs insulin signaling and that its effect may require activation of its receptor GPR75. Taken together, these results provide strong evidence that 20-HETE interferes with insulin function and contributed to diet-driven insulin resistance.
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12
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Fancher IS, Le Master E, Ahn SJ, Adamos C, Lee JC, Berdyshev E, Dull RO, Phillips SA, Levitan I. Impairment of Flow-Sensitive Inwardly Rectifying K + Channels via Disruption of Glycocalyx Mediates Obesity-Induced Endothelial Dysfunction. Arterioscler Thromb Vasc Biol 2020; 40:e240-e255. [PMID: 32698687 DOI: 10.1161/atvbaha.120.314935] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To determine if endothelial dysfunction in a mouse model of diet-induced obesity and in obese humans is mediated by the suppression of endothelial Kir (inwardly rectifying K+) channels. Approach and Results: Endothelial dysfunction, observed as reduced dilations to flow, occurred after feeding mice a high-fat, Western diet for 8 weeks. The functional downregulation of endothelial Kir2.1 using dominant-negative Kir2.1 construct resulted in substantial reductions in the response to flow in mesenteric arteries of lean mice, whereas no effect was observed in arteries of obese mice. Overexpressing wild-type-Kir2.1 in endothelium of arteries from obese mice resulted in full recovery of the flow response. Exposing freshly isolated endothelial cells to fluid shear during patch-clamp electrophysiology revealed that the flow-sensitivity of Kir was virtually abolished in cells from obese mice. Atomic force microscopy revealed that the endothelial glycocalyx was stiffer and the thickness of the glycocalyx layer reduced in arteries from obese mice. We also identified that the length of the glycocalyx is critical to the flow-activation of Kir. Overexpressing Kir2.1 in endothelium of arteries from obese mice restored flow- and heparanase-sensitivity, indicating an important role for heparan sulfates in the flow-activation of Kir. Furthermore, the Kir2.1-dependent component of flow-induced vasodilation was lost in the endothelium of resistance arteries of obese humans obtained from biopsies collected during bariatric surgery. CONCLUSIONS We conclude that obesity-induced impairment of flow-induced vasodilation is attributed to the loss of flow-sensitivity of endothelial Kir channels and propose that the latter is mediated by the biophysical alterations of the glycocalyx.
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Affiliation(s)
- Ibra S Fancher
- From the Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine (I.S.F., E.L.M., S.J.A., C.A., I.L.), University of Illinois at Chicago
| | - Elizabeth Le Master
- From the Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine (I.S.F., E.L.M., S.J.A., C.A., I.L.), University of Illinois at Chicago
| | - Sang Joon Ahn
- From the Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine (I.S.F., E.L.M., S.J.A., C.A., I.L.), University of Illinois at Chicago
| | - Crystal Adamos
- From the Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine (I.S.F., E.L.M., S.J.A., C.A., I.L.), University of Illinois at Chicago
| | - James C Lee
- Departement of Bioengineering (J.C.L.), University of Illinois at Chicago
| | - Evgeny Berdyshev
- Division of Pulmonary, Critical Care and Sleep Medicine, Departement of Medicine, National Jewish Health, Denver, CO (E.B.)
| | - Randal O Dull
- Department of Anesthesiology, University of Arizona College of Medicine, Banner-University Medical Center, Tucson (R.O.D.)
| | - Shane A Phillips
- Department of Physical Therapy (S.A.P.), University of Illinois at Chicago
| | - Irena Levitan
- From the Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine (I.S.F., E.L.M., S.J.A., C.A., I.L.), University of Illinois at Chicago
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13
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Nwadozi E, Rudnicki M, De Ciantis M, Milkovich S, Pulbere A, Roudier E, Birot O, Gustafsson T, Ellis CG, Haas TL. High-fat diet pre-conditioning improves microvascular remodelling during regeneration of ischaemic mouse skeletal muscle. Acta Physiol (Oxf) 2020; 229:e13449. [PMID: 32012450 DOI: 10.1111/apha.13449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/26/2020] [Accepted: 01/28/2020] [Indexed: 12/25/2022]
Abstract
AIM Critical limb ischaemia (CLI) is characterized by inadequate angiogenesis, arteriolar remodelling and chronic myopathy, which are most severe in type 2 diabetic patients. Hypertriglyceridaemia, commonly observed in these patients, compromises macrovascular function. However, the effects of high-fat diet-induced increases in circulating lipids on microvascular remodelling are not established. Here, we investigated if high-fat diet would mimic the detrimental effect of type 2 diabetes on post-ischaemia vascular remodelling and muscle regeneration, using a mouse model of hindlimb ischaemia. METHODS Male C57Bl6/J mice were fed with normal or high-fat diets for 8 weeks prior to unilateral femoral artery ligation. Laser doppler imaging was used to assess limb perfusion recovery. Vascular recovery, inflammation, myofibre regeneration and fibrosis were assessed at 4 or 14 days post-ligation by histology and RNA analyses. Capillary-level haemodynamics were assessed by intravital microscopy of control and regenerating muscles 14 days post-ligation. RESULTS High-fat diet increased muscle succinate dehydrogenase activity and capillary-level oxygen supply. At 4 days post-ligation, no diet differences were detected in muscle damage, inflammatory infiltration or capillary activation. At 14 days post-ligation, high fat-fed mice displayed accelerated limb blood flow recovery, elevated capillary and arteriole densities as well as greater red blood cell supply rates and capillary-level oxygen supply. Regenerating muscles from high fat-fed mice displayed lower interstitial fat and collagen deposition. CONCLUSION The muscle-level adaptations to high-fat diet improved multiple aspects of muscle recovery in response to ischaemia and did not recapitulate the worse outcomes seen in diabetic CLI patients.
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Affiliation(s)
- Emmanuel Nwadozi
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Martina Rudnicki
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Matthew De Ciantis
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Stephanie Milkovich
- Department of Medical Biophysics University of Western Ontario London ON Canada
| | - Alexandru Pulbere
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Emilie Roudier
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Olivier Birot
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
| | - Thomas Gustafsson
- Division of Clinical Physiology Department of Laboratory Medicine Karolinska Institutet Stockholm Sweden
- Unit of Clinical Physiology Karolinska University Hospital Stockholm Sweden
| | | | - Tara L. Haas
- School of Kinesiology and Health Science Muscle Health Research Centre Angiogenesis Research Group York University Toronto ON Canada
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14
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Sorop O, van de Wouw J, Chandler S, Ohanyan V, Tune JD, Chilian WM, Merkus D, Bender SB, Duncker DJ. Experimental animal models of coronary microvascular dysfunction. Cardiovasc Res 2020; 116:756-770. [PMID: 31926020 PMCID: PMC7061277 DOI: 10.1093/cvr/cvaa002] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/25/2019] [Accepted: 01/06/2020] [Indexed: 12/14/2022] Open
Abstract
Coronary microvascular dysfunction (CMD) is commonly present in patients with metabolic derangements and is increasingly recognized as an important contributor to myocardial ischaemia, both in the presence and absence of epicardial coronary atherosclerosis. The latter condition is termed 'ischaemia and no obstructive coronary artery disease' (INOCA). Notwithstanding the high prevalence of INOCA, effective treatment remains elusive. Although to date there is no animal model for INOCA, animal models of CMD, one of the hallmarks of INOCA, offer excellent test models for enhancing our understanding of the pathophysiology of CMD and for investigating novel therapies. This article presents an overview of currently available experimental models of CMD-with an emphasis on metabolic derangements as risk factors-in dogs, swine, rabbits, rats, and mice. In all available animal models, metabolic derangements are most often induced by a high-fat diet (HFD) and/or diabetes mellitus via injection of alloxan or streptozotocin, but there is also a wide variety of spontaneous as well as transgenic animal models which develop metabolic derangements. Depending on the number, severity, and duration of exposure to risk factors-all these animal models show perturbations in coronary microvascular (endothelial) function and structure, similar to what has been observed in patients with INOCA and comorbid conditions. The use of these animal models will be instrumental in identifying novel therapeutic targets and for the subsequent development and testing of novel therapeutic interventions to combat ischaemic heart disease, the number one cause of death worldwide.
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Affiliation(s)
- Oana Sorop
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Jens van de Wouw
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Selena Chandler
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Vahagn Ohanyan
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Johnathan D Tune
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN, USA
| | - William M Chilian
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Daphne Merkus
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
- Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Marchioninistr. 27, 81377 Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance (MHA), 81377 Munich, Germany
| | - Shawn B Bender
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Research Service, Harry S Truman Memorial Veterans Hospital, Columbia, MO, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
| | - Dirk J Duncker
- Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands
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15
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Li XX, Ling SK, Hu MY, Ma Y, Li Y, Huang PL. Protective effects of acarbose against vascular endothelial dysfunction through inhibiting Nox4/NLRP3 inflammasome pathway in diabetic rats. Free Radic Biol Med 2019; 145:175-186. [PMID: 31541678 DOI: 10.1016/j.freeradbiomed.2019.09.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/01/2019] [Accepted: 09/17/2019] [Indexed: 11/16/2022]
Abstract
The cardiovascular efficacy of glucose-lowering drugs is needed due to the cardiovascular complication in type 2 diabetes mellitus (T2DM). Acarbose is an α-glucosidase inhibitor that suppresses postprandial hyperglycemia, however, the cardiovascular protection of acarbose has still remained controversial. NLRP3 inflammasome activation mediated tight junction disruption, a hallmark event of endothelial barrier dysfunction leading to endothelial hyperpermeability in diabetes. Given the anti-inflammatory property of acarbose, it was investigated that acarbose protected against vascular endothelial barrier dysfunction through inhibiting NLRP3 inflammasome in vascular endothelial cells in T2DM rats. The rat aortic endothelial cells (RAECs) were incubated with high glucose (HG, 30 mM) for 24 h in vitro. It was found that HG significantly induced the formation and activation of NLRP3 inflammasome, which was markedly blocked by acarbose treatment. Furthermore, acarbose blocked the Nox4-dependent superoxide (O2.-) generation, which regulated NLRP3 inflammasome in RAECs. Importantly, we found that acarbose remarkably enhanced the junction protein expression of ZO-1 and VE-Cadherin and consequently abolished vascular hyperpermeability, which was associated with inhibiting NLRP3 inflammasome in RAECs. In vivo, acarbose intervention relieved vascular leakage in the heart of diabetic rats injected with Evans blue dye and the vasodilatory response to acetylcholine, which was accompanied with the restoration of ZO-1, VE-Cadherin, Nox4 and NLRP3 inflammasome in the aortal endothelium of diabetic rats. Taken together, our data indicated that acarbose ameliorated endothelial barrier dysfunction by directly inhibiting NLRP3 inflammasome which was dependent on inhibiting Nox4 oxidase-dependent O2.- production. These properties might carry a potential significance for acarbose in cardiovascular protection in diabetic patients.
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Affiliation(s)
- Xiao-Xue Li
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Sun-Kai Ling
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Ming-Yue Hu
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Yu Ma
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Yuan Li
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Pei-Lin Huang
- Department of Pathology and Pathophysiology, Southeast University School of Medicine, Nanjing, 210009, China.
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16
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Lubomirov LT, Gagov H, Schroeter MM, Wiesner RJ, Franko A. Augmented contractility of murine femoral arteries in a streptozotocin diabetes model is related to increased phosphorylation of MYPT1. Physiol Rep 2019; 7:e13975. [PMID: 30740930 PMCID: PMC6369311 DOI: 10.14814/phy2.13975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 12/13/2018] [Indexed: 12/19/2022] Open
Abstract
Diabetes mellitus (DM) is a metabolic disorder with high prevalence, and a major risk factor for macro- and microvascular abnormalities. This study was undertaken to explore the mechanisms of hypercontractility of murine femoral arteries (FA) obtained from mice with streptozotocin (STZ)-induced diabetes and its relation to the phosphorylation profile of the myosin phosphatase target subunit 1, MYPT1. The immunoreactivity of MYPT1 toward phospho-MYPT1-T696, MYPT1-T853, or MYPT1-S695, used as a read out for MYPT1 phosphorylation, has been studied by Western Blotting. Contractile activity of FA from control and STZ mice has been studied by wire myography. At basal conditions (no treatment), the immunoreactivity of MYPT1-T696/T853 was ~2-fold higher in the STZ arteries compared with controls. No changes in MYPT1-T696/853 phosphorylation were observed after stimulation with the Thromboxan-A2 analog, U46619. Neither basal nor U46619-stimulated phosphorylation of MYPT1 at S695 was affected by STZ treatment. Mechanical distensibility and basal tone of FA obtained from STZ animals were similar to controls. Maximal force after treatment of FA with the contractile agonists phenylephrine (10 μmol/L) or U46619 (1 μmol/L) was augmented in the arteries of STZ mice by ~2- and ~1.5-fold, respectively. In summary, our study suggests that development of a hypercontractile phenotype in murine FA in STZ diabetes is at least partially related to an increase in phosphorylation of MLCP at MYPT1-T696/853. Interestingly, the phosphorylation at S695 site was not altered in STZ-induced diabetes, supporting the view that S695 may serve as a sensor for mechanical activity which is not directly involved in tone regulation.
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Affiliation(s)
| | - Hristo Gagov
- Faculty of BiologySofia University St. Kliment OhridskiSofiaBulgaria
| | | | - Rudolf J. Wiesner
- Institute of Vegetative PhysiologyUniversity of CologneKölnGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)KölnGermany
| | - Andras Franko
- Institute of Vegetative PhysiologyUniversity of CologneKölnGermany
- German Center for Diabetes Research (DZD e.V.)NeuherbergGermany
- Division of EndocrinologyDepartment of Internal Medicine IVDiabetology, Angiology, Nephrology and Clinical ChemistryUniversity of TübingenTübingenGermany
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17
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Gilani A, Pandey V, Garcia V, Agostinucci K, Singh SP, Schragenheim J, Bellner L, Falck JR, Paudyal MP, Capdevila JH, Abraham NG, Laniado Schwartzman M. High-fat diet-induced obesity and insulin resistance in CYP4a14 -/- mice is mediated by 20-HETE. Am J Physiol Regul Integr Comp Physiol 2018; 315:R934-R944. [PMID: 30088983 PMCID: PMC6295494 DOI: 10.1152/ajpregu.00125.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/20/2018] [Accepted: 08/06/2018] [Indexed: 02/06/2023]
Abstract
20-Hydroxyeicosatetraenoic acid (20-HETE) has been shown to positively correlate with body mass index, hyperglycemia, and plasma insulin levels. This study seeks to identify a causal relationship between 20-HETE and obesity-driven insulin resistance. Cyp4a14-/- male mice, a model of 20-HETE overproduction, were fed a regular or high-fat diet (HFD) for 15 wk. 20-SOLA [2,5,8,11,14,17-hexaoxanonadecan-19-yl 20-hydroxyeicosa-6( Z),15( Z)-dienoate], a 20-HETE antagonist, was administered from week 0 or week 7 of HFD. HFD-fed mice gained significant weight (16.7 ± 3.2 vs. 3.8 ± 0.35 g, P < 0.05) and developed hyperglycemia (157 ± 3 vs. 121 ± 7 mg/dl, P < 0.05) and hyperinsulinemia (2.3 ± 0.4 vs. 0.5 ± 0.1 ng/ml, P < 0.05) compared with regular diet-fed mice. 20-SOLA attenuated HFD-induced weight gain (9.4 ± 1 vs. 16.7 ± 3 g, P < 0.05) and normalized the hyperglycemia (157 ± 7 vs. 102 ± 5 mg/dl, P < 0.05) and hyperinsulinemia (1.1 ± 0.1 vs. 2.3 ± 0.4 ng/ml, P < 0.05). The impaired glucose homeostasis and insulin resistance in HFD-fed mice evidenced by reduced insulin and glucose tolerance were also ameliorated by 20-SOLA. Circulatory and adipose tissue 20-HETE levels significantly increased in HFD-fed mice correlating with impaired insulin signaling, including reduction in insulin receptor tyrosine (Y972) phosphorylation and increased serine (S307) phosphorylation of the insulin receptor substrate-1 (IRS-1). 20-SOLA treatments prevented changes in insulin signaling. These findings indicate that 20-HETE contributes to HFD-induced obesity, insulin resistance, and impaired insulin signaling.
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Affiliation(s)
- Ankit Gilani
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Varunkumar Pandey
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Victor Garcia
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Kevin Agostinucci
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Shailendra P Singh
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Joseph Schragenheim
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - Lars Bellner
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
| | - John R Falck
- Department of Biochemistry, University of Texas Southwestern Medical Center, Texas
| | - Mahesh P Paudyal
- Department of Biochemistry, University of Texas Southwestern Medical Center, Texas
| | - Jorge H Capdevila
- Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Nader G Abraham
- Departments of Pharmacology, New York Medical College School of Medicine, Valhalla, New York
- Department of Medicine, New York Medical College School of Medicine, Valhalla, New York
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18
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Chang F, Flavahan S, Flavahan NA. Potential pitfalls in analyzing structural uncoupling of eNOS: aging is not associated with increased enzyme monomerization. Am J Physiol Heart Circ Physiol 2018; 316:H80-H88. [PMID: 30289292 DOI: 10.1152/ajpheart.00506.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Homodimer formation is essential for the normal activity of endothelial nitric oxide synthase (eNOS). Structural uncoupling of eNOS, with generation of enzyme monomers, is thought to contribute to endothelial dysfunction in several vascular disorders, including aging. However, low-temperature SDS-PAGE of healthy arteries has revealed considerable variation between studies in the relative expression of eNOS dimers and monomers. While assessing structural uncoupling of eNOS in aging arteries, we identified methodological pitfalls that might contribute to such variation. Therefore, using human cultured aortic endothelial cells and aortas from young and aged Fischer-344 rats, we investigated optimal approaches for analyzing the expression of eNOS monomers and dimers. The results demonstrated that published differences in treatment of cell lysates can significantly impact the relative expression of several eNOS species, including denatured monomers, partially folded monomers, dimers, and higher-order oligomers. In aortas, experiments initially confirmed a large increase in eNOS monomers in aging arteries, consistent with structural uncoupling. However, these monomers were actually endogenous IgG, which, under these conditions, has mobility similar to eNOS monomers. Increased IgG levels in aged aortas likely reflect the aging-induced disruption of endothelial junctions and increased arterial penetration of IgG. After removal of the IgG signal, there were low levels of eNOS monomers in young arteries, which were not significantly different in aged arteries. Therefore, structural uncoupling of eNOS is not a prominent feature in young healthy arteries, and the process is not increased by aging. The study also identifies optimal approaches to analyze eNOS dimers and monomers. NEW & NOTEWORTHY Structural uncoupling of endothelial nitric oxide synthase (eNOS) is considered central to endothelial dysfunction. However, reported levels of eNOS dimers and monomers vary widely, even in healthy arteries. We demonstrate that sample processing can alter relative levels of eNOS species. Moreover, endothelial dysfunction in aging aortas results in IgG accumulation, which, because of similar mobility to eNOS monomers, could be misinterpreted as structural uncoupling. Indeed, enzyme monomerization is not prominent in young or aging arteries.
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Affiliation(s)
- Fumin Chang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Sheila Flavahan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
| | - Nicholas A Flavahan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University , Baltimore, Maryland
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19
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Furuuchi R, Shimizu I, Yoshida Y, Hayashi Y, Ikegami R, Suda M, Katsuumi G, Wakasugi T, Nakao M, Minamino T. Boysenberry polyphenol inhibits endothelial dysfunction and improves vascular health. PLoS One 2018; 13:e0202051. [PMID: 30106986 PMCID: PMC6091942 DOI: 10.1371/journal.pone.0202051] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 07/26/2018] [Indexed: 12/17/2022] Open
Abstract
Endothelial cells have an important role in maintaining vascular homeostasis. Age-related disorders (including obesity, diabetes, and hypertension) or aging per se induce endothelial dysfunction that predisposes to the development of atherosclerosis. Polyphenols have been reported to suppress age-related endothelial cell disorders, but their role in vascular function is yet to be determined. We investigated the influence of boysenberry polyphenol on vascular health under metabolic stress in a murine model of dietary obesity. We found that administration of boysenberry polyphenol suppressed production of reactive oxygen species (ROS) and increased production of nitric oxide (NO) in the aorta. It has been reported that p53 induces cellular senescence and has a crucial role in age-related disorders, including heart failure and diabetes. Administration of boysenberry polyphenol significantly reduced the endothelial p53 level in the aorta and ameliorated endothelial cell dysfunction in iliac arteries under metabolic stress. Boysenberry polyphenol also reduced ROS and p53 levels in cultured human umbilical vein endothelial cells (HUVECs), while increasing NO production. Uncoupled endothelial nitric oxide synthase (eNOS monomer) is known to promote ROS production. We found that boysenberry polyphenol reduced eNOS monomer levels both in vivo and in vitro, along with an increase of eNOS dimerization. To investigate the components of boysenberry polyphenol mediating these favorable biological effects, we extracted the anthocyanin fractions. We found that anthocyanins contributed to suppression of ROS and p53, in association with increased NO production and eNOS dimerization. In an ex vivo study, anthocyanins promoted relaxation of iliac arteries from mice with dietary obesity. These findings indicate that boysenberry polyphenol and anthocyanins, a major component of this polyphenol, inhibit endothelial dysfunction and contribute to maintenance of vascular homeostasis.
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Affiliation(s)
- Ryo Furuuchi
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Bourbon Corporation, Niigata, Japan
| | - Ippei Shimizu
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Division of Molecular Aging and Cell Biology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yohko Yoshida
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Division of Molecular Aging and Cell Biology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yuka Hayashi
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Ryutaro Ikegami
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Masayoshi Suda
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Goro Katsuumi
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Takayuki Wakasugi
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Masaaki Nakao
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tohru Minamino
- Department of Cardiovascular Biology and Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- * E-mail: ,
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20
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Li Q, Su J, Jin SJ, Wei W, Cong XD, Li XX, Xu M. Argirein alleviates vascular endothelial insulin resistance through suppressing the activation of Nox4-dependent O 2- production in diabetic rats. Free Radic Biol Med 2018; 121:169-179. [PMID: 29709706 DOI: 10.1016/j.freeradbiomed.2018.04.573] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/18/2018] [Accepted: 04/24/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Insulin resistance in endothelial cells contributes to the development of cardiovascular disease in type 2 diabetes mellitus (T2DM). Therefore, there are great potential clinical implications in developing pharmacological interventions targeting endothelial insulin resistance. Our previous studies indicated that argirein which was developed by combining rhein with L-arginine by a hydrogen bond, could substantially relieved stress related exacerbation of cardiac failure and alleviated cardiac dysfunction in T2DM, which was associated with suppressing NADPH oxidase activity. However, it is unclear whether argirein treatment attenuates the vascular lesion and dysfunction in T2DM and its underlying mechanisms. METHODS AND RESULTS The rat aortic endothelial cells (RAECs) were used to treat with palmitic acid (PA), a most common saturated free fatty acid, which could induce insulin resistance. It was showed that argirein increased glucose uptake and glucose transporter-4 (Glut4) expression and reversed the phosphorylation of IRS-1-ser307 and AKT-ser473, consequently resulting in the increase of the production of eNOS and NO in PA-induced RAECs. We further found that argirein blocked the Nox4-dependent superoxide (O2-.) generation, which regulated glucose metabolism in RAECs during PA stimulation. In vitro, argirein increased the release of endothelial NO to relieve the vasodilatory response to acetylcholine and insulin, and restored the expression of Nox4 and pIRS-1-ser307 in the aorta endothelium of high-fat diet (HFD)-fed rats following an injection of streptozocin (STZ). CONCLUSION These results suggested that argirein could improve endothelial insulin resistance which was attributed to inhibiting Nox4-dependent redox signaling in RAECs. These studies thus revealed the novel effect of argirein to prevent the vascular complication in T2DM.
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MESH Headings
- Animals
- Anthraquinones/pharmacology
- Arginine/pharmacology
- Cells, Cultured
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/etiology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/etiology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Drug Combinations
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Insulin Resistance
- Male
- NADPH Oxidase 4/genetics
- NADPH Oxidase 4/metabolism
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
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Affiliation(s)
- Qing Li
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, 24 Tong jia Lane, P.O. Box 076, Nanjing, China, 210009
| | - Jie Su
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, 24 Tong jia Lane, P.O. Box 076, Nanjing, China, 210009
| | - Shi-Jie Jin
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou 311400, China
| | - Wei Wei
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, 24 Tong jia Lane, P.O. Box 076, Nanjing, China, 210009
| | - Xiao-Dong Cong
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou 311400, China
| | - Xiao-Xue Li
- Department of Pathology, Medical School of Southeast University, Nanjing 210009, China
| | - Ming Xu
- Department of Clinical Pharmacy, School of Preclinical Medicine and Clinical Pharmacy, China Pharmaceutical University, 24 Tong jia Lane, P.O. Box 076, Nanjing, China, 210009.
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21
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Fancher IS, Ahn SJ, Adamos C, Osborn C, Oh MJ, Fang Y, Reardon CA, Getz GS, Phillips SA, Levitan I. Hypercholesterolemia-Induced Loss of Flow-Induced Vasodilation and Lesion Formation in Apolipoprotein E-Deficient Mice Critically Depend on Inwardly Rectifying K + Channels. J Am Heart Assoc 2018; 7:e007430. [PMID: 29502106 PMCID: PMC5866319 DOI: 10.1161/jaha.117.007430] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/17/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Hypercholesterolemia-induced decreased availability of nitric oxide (NO) is a major factor in cardiovascular disease. We previously established that cholesterol suppresses endothelial inwardly rectifying K+ (Kir) channels and that Kir2.1 is an upstream mediator of flow-induced NO production. Therefore, we tested the hypothesis that suppression of Kir2.1 is responsible for hypercholesterolemia-induced inhibition of flow-induced NO production and flow-induced vasodilation (FIV). We also tested the role of Kir2.1 in the development of atherosclerotic lesions. METHODS AND RESULTS Kir2.1 currents are significantly suppressed in microvascular endothelial cells exposed to acetylated-low-density lipoprotein or isolated from apolipoprotein E-deficient (Apoe-/- ) mice and rescued by cholesterol depletion. Genetic deficiency of Kir2.1 on the background of hypercholesterolemic Apoe-/- mice, Kir2.1+/-/Apoe-/- exhibit the same blunted FIV and flow-induced NO response as Apoe-/- or Kir2.1+/- alone, but while FIV in Apoe-/- mice can be rescued by cholesterol depletion, in Kir2.1+/-/Apoe-/- mice cholesterol depletion has no effect on FIV. Endothelial-specific overexpression of Kir2.1 in arteries from Apoe-/- and Kir2.1+/-/Apoe-/- mice results in full rescue of FIV and NO production in Apoe-/- mice with and without the addition of a high-fat diet. Conversely, endothelial-specific expression of dominant-negative Kir2.1 results in the opposite effect. Kir2.1+/-/Apoe-/- mice also show increased lesion formation, particularly in the atheroresistant area of descending aorta. CONCLUSIONS We conclude that hypercholesterolemia-induced reduction in FIV is largely attributable to cholesterol suppression of Kir2.1 function via the loss of flow-induced NO production, whereas the stages downstream of flow-induced Kir2.1 activation appear to be mostly intact. Kir2.1 channels also have an atheroprotective role.
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MESH Headings
- Animals
- Aorta/metabolism
- Aorta/pathology
- Aortic Diseases/genetics
- Aortic Diseases/metabolism
- Aortic Diseases/pathology
- Aortic Diseases/physiopathology
- Atherosclerosis/genetics
- Atherosclerosis/metabolism
- Atherosclerosis/pathology
- Atherosclerosis/physiopathology
- Cells, Cultured
- Cholesterol/blood
- Disease Models, Animal
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Hypercholesterolemia/genetics
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/pathology
- Hypercholesterolemia/physiopathology
- Male
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice, Inbred C57BL
- Mice, Knockout, ApoE
- Nitric Oxide/metabolism
- Plaque, Atherosclerotic
- Potassium Channels, Inwardly Rectifying/deficiency
- Potassium Channels, Inwardly Rectifying/genetics
- Potassium Channels, Inwardly Rectifying/metabolism
- Signal Transduction
- Vasodilation
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Affiliation(s)
- Ibra S Fancher
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Sang Joon Ahn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Crystal Adamos
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Catherine Osborn
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
| | - Myung-Jin Oh
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | - Yun Fang
- Section of Pulmonary and Critical Care, Department of Medicine, University of Chicago, IL
| | | | | | - Shane A Phillips
- Department of Physical Therapy, University of Illinois at Chicago, IL
| | - Irena Levitan
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, IL
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22
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Suppression of GRK2 expression reduces endothelial dysfunction by restoring glucose homeostasis. Sci Rep 2017; 7:8436. [PMID: 28814745 PMCID: PMC5559446 DOI: 10.1038/s41598-017-08998-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/20/2017] [Indexed: 01/04/2023] Open
Abstract
Despite the associations between diabetic complications and vascular endothelial dysfunction, a direct therapeutic method targeting endothelial dysfunction remains poorly characterized. We have previously shown that chemical inhibition of G-protein-coupled receptor kinase 2 (GRK2) slightly enhances insulin sensitivity and reduces endothelial dysfunction in type 2 diabetic mice. In this study, we identified GRK2 as a novel therapeutic target of diabetic endothelial dysfunction and investigated the effect on diabetic endothelial dysfunction through the systemic administration of GRK2 siRNA using a hydrodynamic-based procedure, resulting in suppression of increased GRK2 protein levels in the liver. Suppressed GRK2 levels in the liver markedly improved glucose homeostasis, as well as improved the impaired endothelial Akt/eNOS-dependent signal activation (insulin-stimulated phosphorylation of Akt and eNOS) and vascular responses (clonidine-induced and insulin-induced endothelial-dependent relaxation response and phenylephrine-induced contractile response) in type 2 diabetic aortas. Interestingly, insulin-stimulated Akt/eNOS signaling was increased only by normalizing the glucose concentration in human umbilical vein endothelial cells (HUVECs) with GRK2 overexpression, suggesting of an important role of hepatic GRK2. Our results clarified the relationship among hepatic GRK2, glucose homeostasis, and vascular endothelial function. Liver-targeting GRK2 siRNA delivery represents a novel therapeutic tool to restore glucose homeostasis and reduce endothelial dysfunction.
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23
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Cui SX, Epstein FH. MRI assessment of coronary microvascular endothelial nitric oxide synthase function using myocardial T 1 mapping. Magn Reson Med 2017; 79:2246-2253. [PMID: 28782150 DOI: 10.1002/mrm.26870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 06/28/2017] [Accepted: 07/19/2017] [Indexed: 01/07/2023]
Abstract
PURPOSE Endothelial nitric oxide synthase (eNOS) plays a central role in regulating vascular tone, blood flow, and microvascular permeability. Endothelial dysfunction, including eNOS dysfunction, is an early biomarker of vascular disease. This study aimed to show that myocardial T1 mapping during nitric oxide synthase (NOS) inhibition could assess coronary microvascular eNOS function. METHODS Wild-type mice, eNOS-/- mice, and wild-type mice fed a high-fat diet underwent T1 mapping at baseline and for 20 min after injection of NG -nitro-L-arginine methyl ester (LNAME), a NOS inhibitor. First-pass perfusion MRI was performed in wild-type mice at baseline and 5 min after LNAME injection. RESULTS T1 mapping detected an increase in myocardial T1 5 min after an injection of 4 mg/kg LNAME compared with baseline in control mice (T1 = 1515 ± 30 ms with LNAME versus T1 = 1402 ± 30 ms at baseline, P < 0.05). No change in myocardial T1 after LNAME injection was observed in eNOS-/- mice. The change in T1 after LNAME injection was less in high-fat-diet mice (ΔT1 = 31 ± 14 ms at 12 weeks of diet and ΔT1 = 16 ± 17 ms at 18 weeks of diet) compared with mice fed a standard diet (ΔT1 = 113 ± 15 ms), with P < 0.05. First-pass MRI measured similar perfusion at baseline and 5 min after LNAME injection. CONCLUSIONS NOS inhibition causes an increase in myocardial T1 in healthy mice, and this effect is mediated through eNOS. T1 mapping during NOS inhibition detects coronary microvascular eNOS dysfunction in high-fat-diet mice. T1 mapping during NOS inhibition may be useful in preclinical studies aiming to investigate mechanisms underlying and therapies for coronary microvascular eNOS dysfunction. Magn Reson Med 79:2246-2253, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Sophia X Cui
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Frederick H Epstein
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Radiology, University of Virginia, Charlottesville, Virginia, USA
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24
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Obesity Induces Artery-Specific Alterations: Evaluation of Vascular Function and Inflammatory and Smooth Muscle Phenotypic Markers. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5038602. [PMID: 28466012 PMCID: PMC5390568 DOI: 10.1155/2017/5038602] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 03/19/2017] [Indexed: 02/06/2023]
Abstract
Vascular alterations are expected to occur in obese individuals but the impact of obesity could be different depending on the artery type. We aimed to evaluate the obesity effects on the relaxing and contractile responses and inflammatory and smooth muscle (SM) phenotypic markers in two vascular beds. Obesity was induced in C57Bl/6 mice by 16-week high-fat diet and vascular reactivity, mRNA expression of inflammatory and SM phenotypic markers, and collagen deposition were evaluated in small mesenteric arteries (SMA) and thoracic aorta (TA). Endothelium-dependent relaxation in SMA and TA was not modified by obesity. In contrast, contraction induced by depolarization and contractile agonists was reduced in SMA, whereas only contraction induced by adrenergic agonist was reduced in TA of obese mice. Obesity increased the mRNA expression of pro- and anti-inflammatory cytokines in SMA and TA. The expression of genes necessary for maintaining contractile ability was increased by obesity, but the increase was more pronounced in TA. Collagen deposition was increased in SMA, but not in TA, of obese mice. Although the endothelial function was still preserved, the SM of the two artery types was impaired by obesity, but the impairment was higher in SMA, which could be associated with SM phenotypic changes.
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25
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Peroxynitrite: From interception to signaling. Arch Biochem Biophys 2016; 595:153-60. [PMID: 27095233 DOI: 10.1016/j.abb.2015.06.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 06/12/2015] [Indexed: 12/18/2022]
Abstract
Peroxynitrite is a strong oxidant and nitrating species that mediates certain biological effects of superoxide and nitrogen monoxide. These biological effects include oxidative damage to proteins as well as the formation of 3-nitrotyrosyl moieties in proteins. As a consequence, such proteins may lose their activity, gain altered function, or become prone to proteolytic degradation - resulting in modulation of cellular protein turnover and in the modulation of signaling cascades. In analogy to hydrogen peroxide, peroxynitrite may be scavenged by selenoproteins like glutathione peroxidase-1 (GPx-1) or by selenocompounds with a GPx-like activity, such as ebselen; in further analogy to H2O2, peroxiredoxins have also been established as contributors to peroxynitrite reduction. This review covers three aspects of peroxynitrite biochemistry, (i) the interaction of selenocompounds/-proteins with peroxynitrite, (ii) peroxynitrite-induced modulation of cellular proteolysis, and (iii) peroxynitrite-induced modulation of cellular signaling.
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26
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Catry E, Neyrinck AM, Lobysheva I, Pachikian BD, Van Hul M, Cani PD, Dessy C, Delzenne NM. Nutritional depletion in n-3 PUFA in apoE knock-out mice: A new model of endothelial dysfunction associated with fatty liver disease. Mol Nutr Food Res 2016; 60:2198-2207. [PMID: 27136390 DOI: 10.1002/mnfr.201500930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/04/2016] [Accepted: 04/04/2016] [Indexed: 12/18/2022]
Abstract
SCOPE Western diets are characterized by low intake of n-3 PUFA compensated by constant amounts of n-6 PUFA. Reduced intake of n-3 PUFA is associated with increased cardiovascular risk, as observed in nonalcoholic fatty liver disease patients. The study aimed to evaluating the impact of dietary n-3 PUFA depletion on endothelial function, an early key event of cardiovascular diseases. METHODS AND RESULTS C57Bl/6J or apolipoprotein E knock-out (apoE-/- ) were fed control (CT) or n-3 PUFA-depleted diets (DEF) for 12 wks. Mice fed n-3 DEF diet developed a hepatic steatosis, linked to changes in hepatic expression of genes controlled by Sterol Regulatory Element Binding Protein-1 and -2. Vascular function was assessed on second- and third-order mesenteric arteries and n-3 PUFA-depleted apoE-/- mice presented endothelial dysfunction characterized by decreased vasorelaxation in response of acetylcholine. The presence of a nitric oxide synthase (NOS) inhibitor blunted the relaxation in each groups and heme-nitrosylated hemoglobin blood (Hb-NO) level was significantly lower in n-3 PUFA-depleted apoE-/- mice. CONCLUSION Twelve weeks of n-3 DEF diet promote steatosis and accelerate the process of endothelial dysfunction in apoE-/- mice by a mechanism involving the NOS/NO pathway. We propose n-3 PUFA-depleted apoE-/- mice as a new model to study endothelial dysfunction related to hepatic steatosis independently of obesity.
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Affiliation(s)
- Emilie Catry
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Audrey M Neyrinck
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Irina Lobysheva
- Pôle de Pharmacologie et Thérapeutique, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Barbara D Pachikian
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Matthias Van Hul
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,Walloon Excellence in Life sciences and Biotechnology (WELBIO), Wavre, Belgium
| | - Patrice D Cani
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,Walloon Excellence in Life sciences and Biotechnology (WELBIO), Wavre, Belgium
| | - Chantal Dessy
- Pôle de Pharmacologie et Thérapeutique, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Nathalie M Delzenne
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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27
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Ryan MJ, Coleman TT, Sasser JM, Pittman KM, Hankins MW, Stec DE. Vascular smooth muscle-specific deletion of the leptin receptor attenuates leptin-induced alterations in vascular relaxation. Am J Physiol Regul Integr Comp Physiol 2016; 310:R960-7. [PMID: 26936780 DOI: 10.1152/ajpregu.00336.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 02/23/2016] [Indexed: 01/09/2023]
Abstract
Obesity is a risk factor for cardiovascular disease and is associated with increased plasma levels of the adipose-derived hormone leptin. Vascular smooth muscle cells (VSMC) express leptin receptors (LepR); however, their physiological role is unclear. We hypothesized that leptin, at levels to mimic morbid obesity, impairs vascular relaxation. To test this, we used control and VSM-LepR knockout mice (VSM-LepR KO) created with a tamoxifen-inducible specific Cre recombinase to delete the LepR gene in VSMC. Control (10-12 wk old) and VSM-LepR KO (10-12 wk old) mice were fed a diet containing tamoxifen (50 mg/kg) for 6 wk, after which vascular reactivity was studied in isolated carotid arteries using an organ chamber bath. Vessels were incubated with leptin (100 ng/ml) or vehicle (0.1 mM Tris·HCl) for 30 min. Leptin treatment resulted in significant impairment of vessel relaxation to the endothelial-specific agonist acetylcholine (ACh). When these experiments were repeated in the presence of the superoxide scavenger tempol, relaxation responses to ACh were restored. VSM-LepR deletion resulted in a significant attenuation of leptin-mediated impaired ACh-induced relaxation. These data show that leptin directly impairs vascular relaxation via a VSM-LepR-mediated mechanism, suggesting a potential pathogenic role for leptin to increase cardiovascular risk during obesity.
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Affiliation(s)
- Michael J Ryan
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, Jackson, Mississippi; and
| | - T Taylor Coleman
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, Jackson, Mississippi; and
| | - Jennifer M Sasser
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Katarina M Pittman
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, Jackson, Mississippi; and
| | - Michael W Hankins
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, Jackson, Mississippi; and
| | - David E Stec
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Cardiovascular-Renal Research Center, Jackson, Mississippi; and
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28
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Aging Increases Susceptibility to High Fat Diet-Induced Metabolic Syndrome in C57BL/6 Mice: Improvement in Glycemic and Lipid Profile after Antioxidant Therapy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1987960. [PMID: 27057272 PMCID: PMC4775807 DOI: 10.1155/2016/1987960] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 01/18/2016] [Indexed: 12/27/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has been considered a novel component of the metabolic syndrome (MetS), with the oxidative stress participating in its progression. This study aimed to evaluate the metabolic profile in young and old mice with MetS, and the effects of apocynin and tempol on glycemic and lipid parameters. Young and old C57BL/6 mice with high fat diet- (HFD-) induced MetS received apocynin and tempol 50 mg·kg−1/day in their drinking water for 10 weeks. After HFD, the young group showed elevated fasting glucose, worsened lipid profile in plasma, steatosis, and hepatic lipid peroxidation. Nevertheless, the old group presented significant increase in fasting insulin levels, insulin resistance, plasma and hepatic lipid peroxidation, and pronounced steatosis. The hepatic superoxide dismutase and catalase activity did not differ between the groups. Tempol and apocynin seemed to prevent hepatic lipid deposition in both groups. Furthermore, apocynin improved glucose tolerance and insulin sensitivity in old mice. In summary, old mice are more susceptible to HFD-induced metabolic changes than their young counterparts. Also, the antioxidant therapy improved insulin sensitivity and glucose tolerance, and in addition, apocynin seemed to prevent the HFD-induced hepatic fat deposition, suggesting an important role of oxidative stress in the induction of NAFLD.
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29
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Ali MI, Chen X, Didion SP. Heterozygous eNOS deficiency is associated with oxidative stress and endothelial dysfunction in diet-induced obesity. Physiol Rep 2015; 3:e12630. [PMID: 26660551 PMCID: PMC4760452 DOI: 10.14814/phy2.12630] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 01/08/2023] Open
Abstract
Heterozygous endothelial nitric oxide synthase (eNOS) deficiency is associated with normal endothelium-dependent responses, however, little is known regarding the mechanisms that maintain or impair endothelial function with heterozygous eNOS deficiency. The goals of this study were to (1) determine mechanism(s) which serve to maintain normal endothelial function in the absence of a single eNOS gene; and (2) to determine whether heterozygous eNOS deficiency predisposes blood vessels to endothelial dysfunction in response to a high-fat diet (HFD). Responses of carotid arteries were examined in wild-type (eNOS(+/+)) and heterozygous eNOS-deficient (eNOS(+/-)) treated with either vehicle (saline), N(G)-nitro-L-arginine (L-NNA, 100 μmol/L), an inhibitor of nitric oxide synthase, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 1 μmol/L), an inhibitor of soluble guanylyl cyclase (sGC), and in eNOS(+/+) and eNOS(+/-) mice fed a control (10%) or a 45% HFD (kcal from fat). Responses to acetylcholine (ACh) were similar in vehicle-treated arteries from eNOS(+/+) and eNOS(+/-) mice, and were equally inhibited by L-NNA and ODQ. Phosphorylation of eNOS Ser1176, a site associated with increased eNOS activity, was significantly greater in eNOS(+/-) mice most likely as a compensatory response for the loss of a single eNOS gene. In contrast, responses to ACh were markedly impaired in carotid arteries from eNOS(+/-), but not eNOS(+/+), mice fed a HFD. Vascular superoxide levels as well as plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) were selectively increased in HFD-fed eNOS(+/-) mice. In reconstitution experiments, IL-6 produced concentration-dependent impairment of endothelial responses as well as greater increases in NADPH-stimulated superoxide levels in arteries from eNOS(+/-) mice fed a control diet compared to eNOS(+/+) mice. Our findings of increased Ser1176-phosphorylation reveal a mechanism by which NOS- and sGC-dependent endothelial function can be maintained with heterozygous eNOS deficiency. In addition, heterozygous eNOS deficiency predisposes blood vessels to developing endothelial dysfunction in response to a HFD. The impairment produced by a HFD in eNOS(+/-) mice appears to be mediated by IL-6-induced increases in vascular superoxide. These findings serve as an important example of eNOS haploinsufficiency, one that may contribute to the development of carotid artery disease in obese humans.
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Affiliation(s)
- M Irfan Ali
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - Xunsheng Chen
- Vascular Biology Center, Georgia Regents University, Augusta, Georgia
| | - Sean P Didion
- Department of Pharmacology and Department of Neurology, The University of Mississippi Medical Center, Jackson, Mississippi
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30
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Assar ME, Angulo J, Rodríguez-Mañas L. Diabetes and ageing-induced vascular inflammation. J Physiol 2015; 594:2125-46. [PMID: 26435167 DOI: 10.1113/jp270841] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 09/28/2015] [Indexed: 12/16/2022] Open
Abstract
Diabetes and the ageing process independently increase the risk for cardiovascular disease (CVD). Since incidence of diabetes increases as people get older, the diabetic older adults represent the largest population of diabetic subjects. This group of patients would potentially be threatened by the development of CVD related to both ageing and diabetes. The relationship between CVD, ageing and diabetes is explained by the negative impact of these conditions on vascular function. Functional and clinical evidence supports the role of vascular inflammation induced by the ageing process and by diabetes in vascular impairment and CVD. Inflammatory mechanisms in both aged and diabetic vasculature include pro-inflammatory cytokines, vascular hyperactivation of nuclear factor-кB, increased expression of cyclooxygenase and inducible nitric oxide synthase, imbalanced expression of pro/anti-inflammatory microRNAs, and dysfunctional stress-response systems (sirtuins, Nrf2). In contrast, there are scarce data regarding the interaction of these mechanisms when ageing and diabetes co-exist and its impact on vascular function. Older diabetic animals and humans display higher vascular impairment and CVD risk than those either aged or diabetic, suggesting that chronic low-grade inflammation in ageing creates a vascular environment favouring the mechanisms of vascular damage driven by diabetes. Further research is needed to determine the specific inflammatory mechanisms responsible for exacerbated vascular impairment in older diabetic subjects in order to design effective therapeutic interventions to minimize the impact of vascular inflammation. This would help to prevent or delay CVD and the specific clinical manifestations (cognitive decline, frailty and disability) promoted by diabetes-induced vascular impairment in the elderly.
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Affiliation(s)
- Mariam El Assar
- Instituto de Investigación Sanitaria del Hospital Universitario de Getafe, Getafe, Spain
| | - Javier Angulo
- Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Leocadio Rodríguez-Mañas
- Instituto de Investigación Sanitaria del Hospital Universitario de Getafe, Getafe, Spain.,Servicio de Geriatría, Hospital Universitario de Getafe, Getafe, Spain
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31
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Zhu D, Wang H, Zhang J, Zhang X, Xin C, Zhang F, Lee Y, Zhang L, Lian K, Yan W, Ma X, Liu Y, Tao L. Irisin improves endothelial function in type 2 diabetes through reducing oxidative/nitrative stresses. J Mol Cell Cardiol 2015. [DOI: 10.1016/j.yjmcc.2015.07.015] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Cowen S, McLaughlin SL, Hobbs G, Coad J, Martin KH, Olfert IM, Vona-Davis L. High-Fat, High-Calorie Diet Enhances Mammary Carcinogenesis and Local Inflammation in MMTV-PyMT Mouse Model of Breast Cancer. Cancers (Basel) 2015; 7:1125-42. [PMID: 26132316 PMCID: PMC4586761 DOI: 10.3390/cancers7030828] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/16/2015] [Accepted: 06/18/2015] [Indexed: 01/26/2023] Open
Abstract
Epidemiological studies provide strong evidence that obesity and the associated adipose tissue inflammation are risk factors for breast cancer; however, the molecular mechanisms are poorly understood. We evaluated the effect of a high-fat/high-calorie diet on mammary carcinogenesis in the immunocompetent MMTV-PyMT murine model. Four-week old female mice (20/group) were randomized to receive either a high-fat (HF; 60% kcal as fat) or a low-fat (LF; 16% kcal) diet for eight weeks. Body weights were determined, and tumor volumes measured by ultrasound, each week. At necropsy, the tumors and abdominal visceral fat were weighed and plasma collected. The primary mammary tumors, adjacent mammary fat, and lungs were preserved for histological and immunohistochemical examination and quantification of infiltrating macrophages, crown-like structure (CLS) formation, and microvessel density. The body weight gains, visceral fat weights, the primary mammary tumor growth rates and terminal weights, were all significantly greater in the HF-fed mice. Adipose tissue inflammation in the HF group was indicated by hepatic steatosis, pronounced macrophage infiltration and CLS formation, and elevations in plasma monocyte chemoattractant protein-1 (MCP-1), leptin and proinflammatory cytokine concentrations. HF intake was also associated with higher tumor-associated microvascular density and the proangiogenic factor MCP-1. This study provides preclinical evidence in a spontaneous model of breast cancer that mammary adipose tissue inflammation induced by diet, enhances the recruitment of macrophages and increases tumor vascular density suggesting a role for obesity in creating a microenvironment favorable for angiogenesis in the progression of breast cancer.
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Affiliation(s)
- Sarah Cowen
- Department of Surgery, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
| | - Sarah L McLaughlin
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
| | - Gerald Hobbs
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
- Department of Statistics, West Virginia University, Morgantown, WV 26506, USA.
| | - James Coad
- Department of Pathology, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
| | - Karen H Martin
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
- Department of Neurobiology and Anatomy, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
| | - I Mark Olfert
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
- Department of Human Performance and Exercise Physiology, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
| | - Linda Vona-Davis
- Department of Surgery, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
- Mary Babb Randolph Cancer Center, West Virginia University Health Sciences Center, Morgantown, WV 26506, USA.
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Toyama K, Koibuchi N, Hasegawa Y, Uekawa K, Yasuda O, Sueta D, Nakagawa T, Ma M, Kusaka H, Lin B, Ogawa H, Ichijo H, Ichijo H, Kim-Mitsuyama S. ASK1 is involved in cognitive impairment caused by long-term high-fat diet feeding in mice. Sci Rep 2015; 5:10844. [PMID: 26044555 PMCID: PMC5377457 DOI: 10.1038/srep10844] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/05/2015] [Indexed: 12/31/2022] Open
Abstract
Although high-fat diet intake is known to cause obesity and diabetes, the effect of high-fat diet itself on cognitive function remains to be clarified. We have previously shown that apoptosis signal-regulating kinase 1 (ASK1) is responsible for cognitive impairment caused by chronic cerebral hypoperfusion. The present work, by using ASK1 deficient mice, was undertaken to explore the influence of chronic high-fat diet intake on cognitive function and the role of ASK1. Cognitive function in wild-type mice fed high-fat diet from 2 to 24 months of age was significantly impaired compared to those fed control diet, which was associated with the significant white matter lesions, reduction of hippocampal capillary density, and decrement of hippocampal neuronal cell. However, ASK1 deficiency abolished the development of cognitive impairment and cerebral injury caused by high-fat diet. Our results provided the evidence that high-fat diet itself causes cognitive impairment and ASK1 participates in such cognitive impairment.
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Affiliation(s)
| | | | | | | | - Osamu Yasuda
- Department of Cardiovascular Clinical and Translational Research, Kumamoto University Hospital, Kumamoto
| | | | | | | | | | | | - Hisao Ogawa
- Department of Cardiovascular Medicine, Kumamoto University Graduate School of Medical Sciences, Kumamoto
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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Tajbakhsh S, Aliakbari K, Hussey DJ, Lower KM, Donato AJ, Sokoya EM. Differential Telomere Shortening in Blood versus Arteries in an Animal Model of Type 2 Diabetes. J Diabetes Res 2015; 2015:153829. [PMID: 26346823 PMCID: PMC4545169 DOI: 10.1155/2015/153829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/20/2015] [Accepted: 07/26/2015] [Indexed: 11/18/2022] Open
Abstract
Vascular dysfunction is an early feature of diabetic vascular disease, due to increased oxidative stress and reduced nitric oxide (NO) bioavailability. This can lead to endothelial cell senescence and clinical complications such as stroke. Cells can become senescent by shortened telomeres and oxidative stress is known to accelerate telomere attrition. Sirtuin 1 (SIRT1) has been linked to vascular health by upregulating endothelial nitric oxide synthase (eNOS), suppressing oxidative stress, and attenuating telomere shortening. Accelerated leukocyte telomere attrition appears to be a feature of clinical type 2 diabetes (T2D) and therefore the telomere system may be a potential therapeutic target in preventing vascular complications of T2D. However the effect of T2D on vascular telomere length is currently unknown. We hypothesized that T2D gives rise to shortened leukocyte and vascular telomeres alongside reduced vascular SIRT1 expression and increased oxidative stress. Accelerated telomere attrition was observed in circulating leukocytes, but not arteries, in T2D compared to control rats. T2D rats had blunted arterial SIRT1 and eNOS protein expression levels which were associated with reduced antioxidant defense capacity. Our findings suggest that hyperglycemia and a deficit in vascular SIRT1 per se are not sufficient to prematurely shorten vascular telomeres.
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Affiliation(s)
- Samira Tajbakhsh
- Discipline of Biotechnology, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
| | - Kamelya Aliakbari
- Discipline of Biotechnology, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
| | - Damian J. Hussey
- Discipline of Surgery, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
| | - Karen M. Lower
- Discipline of Haematology, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
| | - Anthony J. Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, UT 84132, USA
| | - Elke M. Sokoya
- Discipline of Human Physiology, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
- *Elke M. Sokoya:
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Yu C, Luo X, Farhat N, Daneault C, Duquette N, Martel C, Lambert J, Thorin-Trescases N, Rosiers CD, Thorin E. Lack of angiopoietin-like-2 expression limits the metabolic stress induced by a high-fat diet and maintains endothelial function in mice. J Am Heart Assoc 2014; 3:jah3618. [PMID: 25128474 PMCID: PMC4310393 DOI: 10.1161/jaha.114.001024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background Angiopoietin‐like‐2 (angptl2) is produced by several cell types including endothelial cells, adipocytes and macrophages, and contributes to the inflammatory process in cardiovascular diseases. We hypothesized that angptl2 impairs endothelial function, and that lowering angptl2 levels protects the endothelium against high‐fat diet (HFD)‐induced fat accumulation and hypercholesterolemia. Methods and Results Acute recombinant angptl2 reduced (P<0.05) acetylcholine‐mediated vasodilation of isolated wild‐type (WT) mouse femoral artery, an effect reversed (P<0.05) by the antioxidant N‐acetylcysteine. Accordingly, in angptl2 knockdown (KD) mice, ACh‐mediated endothelium‐dependent vasodilation was greater (P<0.05) than in WT mice. In arteries from KD mice, prostacyclin contributed to the overall dilation unlike in WT mice. After a 3‐month HFD, overall vasodilation was not altered, but dissecting out the endothelial intrinsic pathways revealed that NO production was reduced in arteries isolated from HFD‐fed WT mice (P<0.05), while NO release was maintained in KD mice. Similarly, endothelium‐derived hyperpolarizing factor (EDHF) was preserved in mesenteric arteries from HFD‐fed KD mice but not in those from WT mice. Finally, the HFD increased (P<0.05) total cholesterol–to–high‐density lipoprotein ratios, low‐density lipoprotein–to–high‐density lipoprotein ratios, and leptin levels in WT mice only, while glycemia remained similar in the 2 strains. KD mice displayed less triglyceride accumulation in the liver (P<0.05 versus WT), and adipocyte diameters in mesenteric and epididymal white adipose tissues were smaller (P<0.05) in KD than in WT fed an HFD, while inflammatory gene expression increased (P<0.05) in the fat of WT mice only. Conclusions Lack of angptl2 expression limits the metabolic stress induced by an HFD and maintains endothelial function in mice.
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Affiliation(s)
- Carol Yu
- Departments of Pharmacology and Surgery, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (C.Y., N.F., T.) Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Xiaoyan Luo
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Nada Farhat
- Departments of Pharmacology and Surgery, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (C.Y., N.F., T.) Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Caroline Daneault
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Natacha Duquette
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Cécile Martel
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Jean Lambert
- Departments of Social and Preventive Medicine, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (J.L.)
| | - Nathalie Thorin-Trescases
- Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Christine Des Rosiers
- Department of Nutrition, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (C.D.R.) Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
| | - Eric Thorin
- Departments of Pharmacology and Surgery, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada (C.Y., N.F., T.) Montreal Heart Institute, Research Center, Montreal, Quebec, Canada (C.Y., X.L., N.F., C.D., N.D., M., N.T.T., C.D.R., T.)
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Sansbury BE, Hill BG. Regulation of obesity and insulin resistance by nitric oxide. Free Radic Biol Med 2014; 73:383-99. [PMID: 24878261 PMCID: PMC4112002 DOI: 10.1016/j.freeradbiomed.2014.05.016] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/16/2014] [Accepted: 05/17/2014] [Indexed: 02/07/2023]
Abstract
Obesity is a risk factor for developing type 2 diabetes and cardiovascular disease and has quickly become a worldwide pandemic with few tangible and safe treatment options. Although it is generally accepted that the primary cause of obesity is energy imbalance, i.e., the calories consumed are greater than are utilized, understanding how caloric balance is regulated has proven a challenge. Many "distal" causes of obesity, such as the structural environment, occupation, and social influences, are exceedingly difficult to change or manipulate. Hence, molecular processes and pathways more proximal to the origins of obesity-those that directly regulate energy metabolism or caloric intake-seem to be more feasible targets for therapy. In particular, nitric oxide (NO) is emerging as a central regulator of energy metabolism and body composition. NO bioavailability is decreased in animal models of diet-induced obesity and in obese and insulin-resistant patients, and increasing NO output has remarkable effects on obesity and insulin resistance. This review discusses the role of NO in regulating adiposity and insulin sensitivity and places its modes of action into context with the known causes and consequences of metabolic disease.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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Fu Y, Duru EA, Davies MG. Effect of metabolic syndrome on the response to arterial injury. J Surg Res 2014; 191:33-41. [PMID: 24972735 DOI: 10.1016/j.jss.2014.05.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/27/2014] [Accepted: 05/16/2014] [Indexed: 12/01/2022]
Abstract
BACKGROUND Metabolic syndrome is now an epidemic in the United States population. Intimal hyperplasia remains the principal lesion in the development of restenosis after vessel wall injury. The aim of this study is to characterize the changes induced in wall morphology in the developing intimal hyperplasia within a murine model in the presence of diabetes (type 1) and metabolic syndrome. METHODS Control (wild type B6), Non Obese Diabetic, and metabolic syndrome (RCS-10) mice were used. The murine femoral wire injury model was used in which a micro wire is passed through a branch of the femoral and used to denude the common femoral and iliac arteries. Specimens were perfusion fixed and sections were stained with hematoxylin and eosin and Movat stains such that dimensional and compositional morphometry could be performed using an ImagePro system. Additional stains for proliferation and apoptosis were used. RESULTS In control mice, the injured femoral arteries develop intimal hyperplasia, which is maximal at 28 d and remains stable to day 56. Sham-operated vessels do not produce such a response. In diabetic mice, the intimal response increased 5-fold with a 2-fold increase in proteoglycan deposition, whereas in the metabolic syndrome mice there was a 6-fold increase in the intimal response and a similar increase in proteoglycan deposition. Collagen deposition was different with a 22-fold increase over control in collagen deposition in diabetes and a 100-fold increase over control in collagen deposition in metabolic syndrome as compared with the control injury mice. Maximal vascular smooth muscle cell (VSMC) proliferation was decreased in both diabetes and metabolic syndrome compared with controls, whereas early cell apoptosis in both diabetes and metabolic syndrome was sustained over a longer period of time compared with wild-type mice. CONCLUSIONS These data demonstrate that development of intimal hyperplasia is markedly different in diabetes and metabolic syndrome compared with controls, with an increase in collagen deposition, a reduction in VSMC proliferation, and an increase in early VSMC apoptosis. These findings suggest that preventative strategies against restenosis must be tailored for the diabetic and metabolic syndrome patients.
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Affiliation(s)
- Yuyang Fu
- Vascular Biology and Therapeutics Program, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, Texas; Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, Texas
| | - Enrico A Duru
- Vascular Biology and Therapeutics Program, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, Texas; Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, Texas
| | - Mark G Davies
- Vascular Biology and Therapeutics Program, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, Texas; Department of Cardiovascular Surgery, Houston Methodist DeBakey Heart & Vascular Center, Houston Methodist Hospital, Houston, Texas.
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Qin Z, Hou X, Weisbrod RM, Seta F, Cohen RA, Tong X. Nox2 mediates high fat high sucrose diet-induced nitric oxide dysfunction and inflammation in aortic smooth muscle cells. J Mol Cell Cardiol 2014; 72:56-63. [PMID: 24631774 DOI: 10.1016/j.yjmcc.2014.02.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 02/07/2014] [Accepted: 02/25/2014] [Indexed: 12/31/2022]
Abstract
Diet-induced obesity and metabolic syndrome are important contributors to cardiovascular diseases. The decreased nitric oxide (NO) bioactivity in endothelium and the impaired response of smooth muscle cell (SMC) to NO significantly contribute to vascular pathologies, including atherosclerosis and arterial restenosis after angioplasty. Sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) is an important mediator of NO function in both endothelial cells and SMCs, and its irreversible oxidation impairs its stimulation by NO. We used C57BL/6J mice fed a high fat high sucrose diet (HFHSD) to study the role of SMC SERCA in diet-induced obesity and metabolic syndrome. We found that HFHSD upregulated Nox2 based NADPH oxidase, induced inflammation, increased irreversible SERCA oxidation, and suppressed the response of aortic SERCA to NO. Cultured aortic SMCs from mice fed HFHSD showed increased reactive oxygen species production, Nox2 upregulation, irreversible SERCA oxidation, inflammation, and a decreased ability of NO to inhibit SMC migration. Overexpression of wild type SERCA2b or downregulation of Nox2 restored NO-mediated inhibition of migration in SMCs isolated from HFHSD-fed mice. In addition, tumor necrosis factor alpha (TNFα) increased Nox2 which induced SERCA oxidation and inflammation. Taken together, Nox2 induced by HFHSD plays significant roles in controlling SMC responses to NO and TNFα-mediated inflammation, which may contribute to the development of cardiovascular diseases in diet-induced obesity and metabolic syndrome.
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Affiliation(s)
- Zhexue Qin
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA; Department of Cardiovascular Diseases, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Xiuyun Hou
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Robert M Weisbrod
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Francesca Seta
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Richard A Cohen
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Xiaoyong Tong
- Vascular Biology Section, Department of Medicine, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA.
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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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Eskens BJM, Leurgans TM, Vink H, Vanteeffelen JWGE. Early impairment of skeletal muscle endothelial glycocalyx barrier properties in diet-induced obesity in mice. Physiol Rep 2014; 2:e00194. [PMID: 24744873 PMCID: PMC3967677 DOI: 10.1002/phy2.194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 12/03/2013] [Accepted: 12/08/2013] [Indexed: 01/05/2023] Open
Abstract
While previous studies have indicated an important role for the endothelial glycocalyx in regulation of microvascular function, it was recently shown that acute enzymatic glycocalyx degradation in rats was associated with an impaired insulin‐mediated glucose disposal. The aim of this study was to determine whether glycocalyx damage in skeletal muscle occurs at an early stage of diet‐induced obesity (DIO). The microcirculation of the hindlimb muscle of anesthetized C57Bl/6 mice, fed chow (CON) or a high‐fat diet (HFD) for 6 and 18 weeks (w), respectively, was visualized with a Sidestream Dark‐Field camera, and glycocalyx barrier properties were derived from the calculated perfused boundary region (PBR). Subsequently, an intraperitoneal glucose tolerance test was performed and the area under the curve (AUC) of blood glucose was calculated. Impairment of glycocalyx barrier properties was already apparent after 6 weeks of HFD and remained after 18 weeks of HFD (PBR [in μm]: 0.81 ± 0.03 in CON_6w vs. 0.97 ± 0.04 in HFD_6w and 1.02 ± 0.07 in HFD_18w [both P < 0.05]). Glucose intolerance appeared to develop more slowly (AUC [in mmol/L × 120 min]: 989 ± 61 in CON_6w vs. 1204 ± 89 in HFD_6w [P = 0.11] and 1468 ± 84 in HFD_18w [P < 0.05]) than the impairment of glycocalyx barrier properties. The data indicate that damage to the endothelial glycocalyx is an early event in DIO. It is suggested that glycocalyx damage may contribute to the development of insulin resistance in obesity. In this study we assessed glycocalyx barrier properties in skeletal muscle using Sidestream Dark‐Field imaging at an early and later stage of diet‐induced obesity in mice, by feeding them a high‐fat diet for 6 and 18 weeks, respectively. Glycocalyx barrier properties in hindlimb muscle microcirculation were found to be impaired after 6 weeks already. Our results suggest that in obesity glycocalyx damage represents an early aspect of microvascular dysfunction which may as well contribute to the development of glucose intolerance.
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Affiliation(s)
- Bart J M Eskens
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Thomas M Leurgans
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Hans Vink
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Jurgen W G E Vanteeffelen
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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Abstract
The prevalence of obesity has increased remarkably in the past four decades. Because obesity can promote the development of type 2 diabetes and cardiovascular disease, understanding the mechanisms that engender weight gain and discovering safe antiobesity therapies are of critical importance. In particular, the gaseous signaling molecule, nitric oxide (NO), appears to be a central factor regulating adiposity and systemic metabolism. Obese and diabetic states are characterized by a deficit in bioavailable NO, with such decreases commonly attributed to downregulation of endothelial NO synthase (eNOS), loss of eNOS activity, or quenching of NO by its reaction with oxygen radicals. Gain-of-function studies, in which vascular-derived NO has been increased pharmacologically or genetically, reveal remarkable actions of NO on body composition and systemic metabolism. This review addresses the metabolic actions of eNOS and the potential therapeutic utility of harnessing its antiobesogenic effects.
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Affiliation(s)
- Brian E Sansbury
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, Louisville, Kentucky, USA; Department of Physiology and Biophysics, Louisville, Kentucky, USA; Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky, USA.
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Vulesevic B, McNeill B, Geoffrion M, Kuraitis D, McBane JE, Lochhead M, Vanderhyden BC, Korbutt GS, Milne RW, Suuronen EJ. Glyoxalase-1 overexpression in bone marrow cells reverses defective neovascularization in STZ-induced diabetic mice. Cardiovasc Res 2013; 101:306-16. [PMID: 24259499 DOI: 10.1093/cvr/cvt259] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Methylglyoxal (MG) accumulates in diabetes and impairs neovascularization. This study assessed whether overexpressing the MG-metabolizing enzyme glyoxalase-1 (GLO1) in only bone marrow cells (BMCs) could restore neovascularization in ischaemic tissue of streptozotocin-induced diabetic mice. METHODS AND RESULTS After 24 h of hyperglycaemic and hypoxic culture, BMCs from GLO1 overexpressing and wild-type (WT) diabetic mice were compared for migratory potential, viability, and mRNA expression of anti-apoptotic genes (Bcl-2 and Bcl-XL). In vivo, BMCs from enhanced green fluorescent protein (eGFP) mice that overexpress GLO1 were used to reconstitute the BM of diabetic mice (GLO1-diabetics). Diabetic and non-diabetic recipients of WT GFP(+) BM served as controls (WT-diabetics and non-diabetics, respectively). Following hindlimb ischaemia, the mobilization of BMCs was measured by flow cytometry. In hindlimbs, the presence of BM-derived angiogenic (GFP(+)CXCR4(+)) and endothelial (GFP(+)vWF(+)) cells and also arteriole density were determined by immunohistochemistry. Hindlimb perfusion was measured using laser Doppler. GLO1-BMCs had superior migratory potential, increased viability, and greater Bcl-2 and Bcl-XL expression, compared with WT BMCs. In vivo, the mobilization of pro-angiogenic BMCs (CXCR4(+), c-kit(+), and Flk(+)) was enhanced post-ischaemia in GLO1-diabetics compared to WT-diabetics. A greater number of GFP(+)CXCR4(+) and GFP(+)vWF(+) BMCs incorporated into the hindlimb tissue of GLO1-diabetics and non-diabetics than in WT-diabetics. Arteriole and capillary density and perfusion were also greater in GLO1-diabetics and non-diabetics. CONCLUSION This study demonstrates that protection from MG uniquely in BM is sufficient to restore BMC function and neovascularization of ischaemic tissue in diabetes and identifies GLO1 as a potential therapeutic target.
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Affiliation(s)
- Branka Vulesevic
- Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7
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Lynch CM, Kinzenbaw DA, Chen X, Zhan S, Mezzetti E, Filosa J, Ergul A, Faulkner JL, Faraci FM, Didion SP. Nox2-derived superoxide contributes to cerebral vascular dysfunction in diet-induced obesity. Stroke 2013; 44:3195-201. [PMID: 24072007 DOI: 10.1161/strokeaha.113.001366] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Obesity is an increasing epidemic worldwide; however, little is known about effects of obesity produced by high-fat diet (HFD) on the cerebral circulation. The purpose of this study was to examine the functional and temporal effects of a HFD on carotid and cerebral vascular function and to identify mechanisms that contribute to such functional alterations. METHODS Responses of cerebral arterioles (in vivo) and carotid arteries (in vitro) were examined in C57Bl/6 (wild-type) and Nox2-deficient (Nox2(-/-)) mice fed a control (10%) or a HFD (45% or 60% kcal of fat) for 8, 12, 30, or 36 weeks. RESULTS In wild-type mice, a HFD produced obesity and endothelial dysfunction by 12 and 36 weeks in cerebral arterioles and carotid arteries, respectively. Endothelial function could be significantly improved with Tempol (a superoxide scavenger) treatment in wild-type mice fed a HFD. Despite producing a similar degree of obesity in both wild-type and Nox2(-/-) mice, endothelial dysfunction was observed only in wild-type, but not in Nox2(-/-), mice fed a HFD. CONCLUSIONS Endothelial dysfunction produced by a HFD occurs in a temporal manner and appears much earlier in cerebral arterioles than in carotid arteries. Genetic studies revealed that Nox2-derived superoxide plays a major role in endothelial dysfunction produced by a HFD. Such functional changes may serve to predispose blood vessels to reduced vasodilator responses and thus may contribute to alterations in cerebral blood flow associated with obesity.
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Affiliation(s)
- Cynthia M Lynch
- From the Departments of Internal Medicine (C.M.L., D.A.K., F.M.F.) and Pharmacology (F.M.F.), The University of Iowa Carver College of Medicine, Iowa City, IA; Vascular Biology Center (X.C., E.M.) and Department of Physiology, Medical College of Georgia (J.F., A.E.), Georgia Regents University, Augusta, GA; Departments of Pharmacology (S.Z., J.L.F., S.P.D.) and Neurology (S.P.D.), The University of Mississippi Medical Center, Jackson, MS; and Charlie Norwood VA Medical Center, Augusta, GA (A.E.)
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Bonner JS, Lantier L, Hocking KM, Kang L, Owolabi M, James FD, Bracy DP, Brophy CM, Wasserman DH. Relaxin treatment reverses insulin resistance in mice fed a high-fat diet. Diabetes 2013; 62:3251-60. [PMID: 23801576 PMCID: PMC3749347 DOI: 10.2337/db13-0033] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The endogenous hormone relaxin increases vascular reactivity and angiogenesis. We demonstrate that acute relaxin infusion in lean C57BL/6J mice enhances skeletal muscle perfusion and augments muscle glucose uptake during a hyperinsulinemic-euglycemic clamp. However, an acute effect was absent in mice fed a high-fat (HF) diet for 13 weeks. In contrast, mice fed an HF diet for 13 weeks and continuously treated with relaxin for the final 3 weeks of the diet exhibited decreased fasting blood glucose. Insulin-stimulated whole-body glucose disappearance and percent suppression of hepatic glucose production are corrected by chronic relaxin. The increase in peripheral glucose utilization is a result of augmented in vivo skeletal muscle glucose uptake. Relaxin intervention improves endothelial-dependent vascular reactivity and induces a two-fold proliferation in skeletal muscle capillarity. The metabolic effects of the treatment are not attributed to changes in myocellular insulin signaling. Relaxin intervention reverses the accumulation of collagen III in the liver and collagen III and collagen IV in the heart; this is induced by HF feeding. These studies show the potential of relaxin in the treatment of diet-induced insulin resistance and vascular dysfunction. Relaxin provides a novel therapeutic approach targeting the extramyocellular barriers to insulin action, which are critical to the pathogenesis of insulin resistance.
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Affiliation(s)
- Jeffrey S Bonner
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
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Xue J, Wang C, Zhu C, Li Y. ATP-binding cassette transporter G1 protects against endothelial dysfunction induced by high glucose. Diabetes Res Clin Pract 2013; 101:72-80. [PMID: 23693076 DOI: 10.1016/j.diabres.2013.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/28/2013] [Accepted: 04/25/2013] [Indexed: 01/22/2023]
Abstract
AIMS ATP binding cassette transporter G1 (ABCG1), a regulator of cholesterol efflux to HDL, has been shown to decrease in macrophages and smooth muscle cells under high glucose conditions. Endothelial cells have a high capacity to efflux sterols and express ABCG1. In the present study we explored the role of ABCG1 in high glucose-induced endothelial dysfunction. METHODS Human aortic endothelial cells (HAECs) were cultured under high glucose conditions. ABCG1 mRNA and protein expression in HAECs were measured by real time PCR and Western blot. Cholesterol efflux and NO synthesis (NOS) activity were determined by means of scintillation counting. Total intracellular cholesterol was determined by gas-liquid chromatography. The secretion of IL-6 and ICAM-1 was measured using ELISA. The generation of intracellular reactive oxygen species (ROS) was measured using a fluorescence microscope. RESULTS We observed that high glucose suppressed ABCG1 expression and intracellular cholesterol efflux to HDL. Furthermore, high glucose increased the secretion of IL-6 and ICAM, as well as decreased phospho-eNOS protein expression and NOS activity. These processes were reversed by the up-regulation of ABCG1 using the liver X receptor (LXR) agonist T0901307 and an ABCG1 expression vector. In addition, high glucose-induced oxidative stress was reduced by the upregulation of ABCG1. In contrast, knock-down of ABCG1 in HAECs significantly increased the secretion of IL-6 and ICAM, as well as decreased phospho-eNOS protein expression and NOS activity. CONCLUSIONS The present results suggest that ABCG1 plays an important role in protecting against endothelial dysfunction induced by high glucose.
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Affiliation(s)
- Jiahong Xue
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
| | - Congxia Wang
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Canzhan Zhu
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Yongqin Li
- Department of Cardiovascular Medicine, Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
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Low Wang CC, Lu L, Leitner JW, Sarraf M, Gianani R, Draznin B, Greyson CR, Reusch JEB, Schwartz GG. Arterial insulin resistance in Yucatan micropigs with diet-induced obesity and metabolic syndrome. J Diabetes Complications 2013; 27:307-15. [PMID: 23558108 PMCID: PMC3696427 DOI: 10.1016/j.jdiacomp.2013.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 01/29/2013] [Accepted: 02/21/2013] [Indexed: 12/11/2022]
Abstract
AIM Metabolic syndrome affects a large proportion of the population and increases cardiovascular disease risk. Because metabolic syndrome often co-exists clinically with atherosclerosis, it is difficult to distinguish the respective contributions of the components to vascular abnormalities. Accordingly, we utilized a porcine dietary model of metabolic syndrome without atherosclerosis to investigate early abnormalities of vascular function and signaling. METHODS Thirty-two Yucatan micropigs were fed either a high-fat, high-simple-sugar, high-calorie (HFHS) or standard chow diet (STD) for 6 months. Neither diet contained added cholesterol. Blood pressure and flow-mediated vasodilatation were assessed at baseline and 6 months. Aortas were harvested at 6 months to assess histology, insulin signaling, and endothelial nitric oxide (eNOS) phosphorylation. RESULTS HFHS pigs developed characteristics of metabolic syndrome including obesity, dyslipidemia, and insulin resistance, but without histologic evidence of atherosclerosis. Although arterial intima-media thickness did not differ between groups, vascular dysfunction in HFHS was manifest by increased blood pressure and impaired flow-mediated vasodilation of the femoral artery. Compared with STD, aortas from HFHS exhibited increased p85α expression and Ser307 IRS-1 phosphorylation, and blunted insulin-stimulated IRS-1-associated phosphatidylinositol (PI) 3-kinase activity. In the absence of insulin stimulation, aortic Akt Ser473-phosphorylation was greater in HFHS than in STD. With insulin stimulation, Akt phosphorylation increased in STD, but not HFHS. Insulin-induced Ser1177-phosphorylation of eNOS was decreased in HFHS, compared with STD. CONCLUSIONS Pigs with metabolic syndrome develop early vascular dysfunction and aortic insulin signaling abnormalities, and could be a useful model for early human vascular abnormalities in this condition.
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Affiliation(s)
- Cecilia C Low Wang
- Endocrine Section, VA Medical Center, Denver, and University of Colorado Anschutz Medical Campus/School of Medicine, Aurora, CO, USA.
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Prasai MJ, Mughal RS, Wheatcroft SB, Kearney MT, Grant PJ, Scott EM. Diurnal variation in vascular and metabolic function in diet-induced obesity: divergence of insulin resistance and loss of clock rhythm. Diabetes 2013; 62:1981-9. [PMID: 23382450 PMCID: PMC3661613 DOI: 10.2337/db11-1740] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Circadian rhythms are integral to the normal functioning of numerous physiological processes. Evidence from human and mouse studies suggests that loss of rhythm occurs in obesity and cardiovascular disease and may be a neglected contributor to pathophysiology. Obesity has been shown to impair the circadian clock mechanism in liver and adipose tissue but its effect on cardiovascular tissues is unknown. We investigated the effect of diet-induced obesity in C57BL6J mice upon rhythmic transcription of clock genes and diurnal variation in vascular and metabolic systems. In obesity, clock gene function and physiological rhythms were preserved in the vasculature but clock gene transcription in metabolic tissues and rhythms of glucose tolerance and insulin sensitivity were blunted. The most pronounced attenuation of clock rhythm occurred in adipose tissue, where there was also impairment of clock-controlled master metabolic genes and both AMPK mRNA and protein. Across tissues, clock gene disruption was associated with local inflammation but diverged from impairment of insulin signaling. We conclude that vascular tissues are less sensitive to pathological disruption of diurnal rhythms during obesity than metabolic tissues and suggest that cellular disruption of clock gene rhythmicity may occur by mechanisms shared with inflammation but distinct from those leading to insulin resistance.
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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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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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Lotfi S, Patel AS, Mattock K, Egginton S, Smith A, Modarai B. Towards a more relevant hind limb model of muscle ischaemia. Atherosclerosis 2013. [DOI: 10.1016/j.atherosclerosis.2012.10.060] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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