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Zhang Z, Qin S, Wang R, Fang Z, Wang Y, Li F. Circ_0003575 knockdown alleviates ox-LDL-induced human aortic endothelial cell dysfunction in atherosclerosis by miR-637/TRAF6 axis. Clin Hemorheol Microcirc 2023; 85:173-187. [PMID: 37599528 DOI: 10.3233/ch-231858] [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] [Indexed: 08/22/2023]
Abstract
BACKGROUND Circular RNAs (circRNAs) are involved in the progression of atherosclerosis (AS). The present study aimed to determine the functions and mechanism of circ_0003575 in AS. METHODS Oxidized low-density lipoprotein (ox-LDL) was used to induce human aortic endothelial cells (HAECs) to establish an AS cell model. Cell Counting Kit-8 (CCK-8) assay and 5'-ethynyl-2'-deoxyuridine (EdU) assay were conducted to assess cell proliferation. Flow cytometry analysis was utilized to quantify cell apoptosis. Tube formation assay was performed to analyze angiogenesis ability. Enzyme linked immunosorbent assay (ELISA) was used to examine the concentrations of inflammatory factors. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were manipulated for the expression of circ_0003575, microRNA-637 (miR-637) and TNF receptor associated factor 6 (TRAF6). Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were adopted to estimate the downstream targets of circ_0003575. RESULTS Ox-LDL treatment repressed the proliferation and angiogenesis and promoted the apoptosis and inflammation in HAECs. Circ_0003575 knockdown ameliorated ox-LDL-induced injury of HAECs. Circ_0003575 interacted with mi-R-637, which directly targeted TRAF6. Inhibition of miR-637 reversed the impacts of circ_0003575 knockdown on HAEC injury. Moreover, miR-637 overexpression promoted cell proliferation and angiogenesis and inhibited cell apoptosis and inflammation by targeting TRAF6 in ox-LDL-treated HAECs. Further, circ_0003575 silencing inhibited the activation of NF-κB pathway. CONCLUSION Circ_0003575 knockdown alleviated ox-LDL-induced HAEC damage by regulating miR-637/TRAF6 and NF-κB pathways.
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Affiliation(s)
- Zhanshuai Zhang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
| | - Shaoqiang Qin
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
| | - Rui Wang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
| | - Zhiqin Fang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
| | - Yaling Wang
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
| | - Fangjiang Li
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Hebei North University, Zhangjiakou City, Hebei, China
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van de Wouw J, Joles JA. Albumin is an interface between blood plasma and cell membrane, and not just a sponge. Clin Kidney J 2021; 15:624-634. [PMID: 35371452 PMCID: PMC8967674 DOI: 10.1093/ckj/sfab194] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/16/2022] Open
Abstract
Albumin is the most abundant protein in blood plasma and acts as a carrier for many circulating molecules. Hypoalbuminaemia, mostly caused by either renal or liver disease or malnutrition, can perturb vascular homeostasis and is involved in the development of multiple diseases. Here we review four functions of albumin and the consequences of hypoalbuminaemia on vascular homeostasis. (i) Albumin is the main determinant of plasma colloid osmotic pressure. Hypoalbuminaemia was therefore thought to be the main mechanism for oedema in nephrotic syndrome (NS), however, experimental studies showed that intrarenal mechanisms rather than hypoalbuminaemia determine formation and, in particular, maintenance of oedema. (ii) Albumin functions as an interface between lysophosphatidylcholine (LPC) and circulating factors (lipoproteins and erythrocytes) and the endothelium. Consequently, hypoalbuminaemia results in higher LPC levels in lipoproteins and erythrocyte membrane, thereby increasing atherosclerotic properties of low-density lipoprotein and blood viscosity, respectively. Furthermore, albumin dose-dependently restores LPC-induced inhibition of vasodilation. (iii) Hypoalbuminaemia impacts on vascular nitric oxide (NO) signalling by directly increasing NO production in endothelial cells, leading to reduced NO sensitivity of vascular smooth muscle cells. (iv) Lastly, albumin binds free fatty acids (FFAs). FFAs can induce vascular smooth muscle cell apoptosis, uncouple endothelial NO synthase and decrease endothelium-dependent vasodilation. Unbound FFAs can increase the formation of reactive oxygen species by mitochondrial uncoupling in multiple cell types and induce hypertriglyceridemia in NS. In conclusion, albumin acts as an interface in the circulation and hypoalbuminaemia impairs multiple aspects of vascular function that may underlie the association of hypoalbuminaemia with adverse outcomes. However, hypoalbuminaemia is not a key to oedema in NS. These insights have therapeutic implications.
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Affiliation(s)
| | - Jaap A Joles
- Department of Nephrology and Hypertension, University Medical Center, Utrecht, the Netherlands
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3
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Morris G, Berk M, Walder K, O'Neil A, Maes M, Puri BK. The lipid paradox in neuroprogressive disorders: Causes and consequences. Neurosci Biobehav Rev 2021; 128:35-57. [PMID: 34118292 DOI: 10.1016/j.neubiorev.2021.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 04/27/2021] [Accepted: 06/06/2021] [Indexed: 02/07/2023]
Abstract
Chronic systemic inflammation is associated with an increased risk of cardiovascular disease in an environment of low low-density lipoprotein (LDL) and low total cholesterol and with the pathophysiology of neuroprogressive disorders. The causes and consequences of this lipid paradox are explored. Circulating activated neutrophils can release inflammatory molecules such as myeloperoxidase and the pro-inflammatory cytokines interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha. Since activated neutrophils are associated with atherosclerosis and cardiovascular disease and with major depressive disorder, bipolar disorder and schizophrenia, it seems reasonable to hypothesise that the inflammatory molecules released by them may act as mediators of the link between systemic inflammation and the development of atherosclerosis in neuroprogressive disorders. This hypothesis is tested by considering the association at a molecular level of systemic inflammation with increased LDL oxidation; increased small dense LDL levels; increased lipoprotein (a) concentration; secretory phospholipase A2 activation; cytosolic phospholipase A2 activation; increased platelet activation; decreased apolipoprotein A1 levels and function; decreased paroxonase-1 activity; hyperhomocysteinaemia; and metabolic endotoxaemia. These molecular mechanisms suggest potential therapeutic targets.
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Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, CMMR Strategic Research Centre, School of Medicine, Geelong, Victoria, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, the Department of Psychiatry and the Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Adrienne O'Neil
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, King Chulalongkorn University Hospital, Bangkok, Thailand
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Zhu L, Gong X, Gong J, Xuan Y, Fu T, Ni S, Xu L, Ji N. Notoginsenoside R1 upregulates miR-221-3p expression to alleviate ox-LDL-induced apoptosis, inflammation, and oxidative stress by inhibiting the TLR4/NF-κB pathway in HUVECs. ACTA ACUST UNITED AC 2020; 53:e9346. [PMID: 32401923 PMCID: PMC7233198 DOI: 10.1590/1414-431x20209346] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 03/13/2020] [Indexed: 12/14/2022]
Abstract
Atherosclerosis (AS) is a common vascular disease, which can cause apoptosis of vascular endothelial cells. Notoginsenoside R1 (NGR1) is considered an anti-AS drug. MicroRNAs (miRNAs) are believed to play a vital role in cell apoptosis and angiogenesis. This study aimed to explore the mechanism of NGR1 for treating AS through miRNAs. Flow cytometry was used to detect the apoptosis rate. The levels of inflammatory cytokines interleukin (IL)-6 and IL-1β were detected using ELISA. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels were measured using corresponding assay kits. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed to detect miR-221-3p expression. Dual-luciferase reporter and RNA immunoprecipitation assays were carried out to examine the relationship between miR-221-3p and toll-like receptors 4 (TLR4). Also, western blot analysis was performed to determine the levels of TLR4 and nuclear factor kappa B (NF-κB) signaling pathway-related proteins. Oxidized low-density lipoprotein (ox-LDL) induced human umbilical vein endothelial cells (HUVECs) apoptosis, inflammation, and oxidative stress. NGR1 alleviated the negative effect of ox-LDL through promoting the expression of miR-221-3p in HUVECs. TLR4 was a target of miR-221-3p, and its overexpression could reverse the inhibition effects of miR-221-3p on apoptosis, inflammation, and oxidative stress. NGR1 improved miR-221-3p expression to inhibit the activation of the TLR4/NF-κB pathway in ox-LDL-treated HUVECs. NGR1 decreased ox-LDL-induced HUVECs apoptosis, inflammation, and oxidative stress through increasing miR-221-3p expression, thereby inhibiting the activation of the TLR4/NF-κB pathway. This study of the mechanism of NGR1 provided a more theoretical basis for the treatment of AS.
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Affiliation(s)
- Lingbo Zhu
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Xinyan Gong
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Jianping Gong
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Yungang Xuan
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Ting Fu
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Shimao Ni
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Lei Xu
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
| | - Ningning Ji
- Department of Cardiology, Central Hospital of Yiwu, Yiwu, Zhejiang, China
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Jawi MM, Frohlich J, Chan SY. Lipoprotein(a) the Insurgent: A New Insight into the Structure, Function, Metabolism, Pathogenicity, and Medications Affecting Lipoprotein(a) Molecule. J Lipids 2020; 2020:3491764. [PMID: 32099678 PMCID: PMC7016456 DOI: 10.1155/2020/3491764] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/17/2019] [Indexed: 12/15/2022] Open
Abstract
Lipoprotein(a) [Lp(a)], aka "Lp little a", was discovered in the 1960s in the lab of the Norwegian physician Kåre Berg. Since then, we have greatly improved our knowledge of lipids and cardiovascular disease (CVD). Lp(a) is an enigmatic class of lipoprotein that is exclusively formed in the liver and comprises two main components, a single copy of apolipoprotein (apo) B-100 (apo-B100) tethered to a single copy of a protein denoted as apolipoprotein(a) apo(a). Plasma levels of Lp(a) increase soon after birth to a steady concentration within a few months of life. In adults, Lp(a) levels range widely from <2 to 2500 mg/L. Evidence that elevated Lp(a) levels >300 mg/L contribute to CVD is significant. The improvement of isoform-independent assays, together with the insight from epidemiologic studies, meta-analyses, genome-wide association studies, and Mendelian randomization studies, has established Lp(a) as the single most common independent genetically inherited causal risk factor for CVD. This breakthrough elevated Lp(a) from a biomarker of atherosclerotic risk to a target of therapy. With the emergence of promising second-generation antisense therapy, we hope that we can answer the question of whether Lp(a) is ready for prime-time clinic use. In this review, we present an update on the metabolism, pathophysiology, and current/future medical interventions for high levels of Lp(a).
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Affiliation(s)
- Motasim M. Jawi
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Division of Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver V5Z 1M9, Canada
- Department of Clinical PhysiologyCorrection: Department of Physiology, University of Jeddah, P.O. Box: 24, Jeddah 21959, Saudi Arabia
| | - Jiri Frohlich
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - Sammy Y. Chan
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Department of Medicine, Division of Cardiology, University of British Columbia, Vancouver V5Z 1M9, Canada
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Law SH, Chan ML, Marathe GK, Parveen F, Chen CH, Ke LY. An Updated Review of Lysophosphatidylcholine Metabolism in Human Diseases. Int J Mol Sci 2019; 20:ijms20051149. [PMID: 30845751 PMCID: PMC6429061 DOI: 10.3390/ijms20051149] [Citation(s) in RCA: 418] [Impact Index Per Article: 83.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is increasingly recognized as a key marker/factor positively associated with cardiovascular and neurodegenerative diseases. However, findings from recent clinical lipidomic studies of LPC have been controversial. A key issue is the complexity of the enzymatic cascade involved in LPC metabolism. Here, we address the coordination of these enzymes and the derangement that may disrupt LPC homeostasis, leading to metabolic disorders. LPC is mainly derived from the turnover of phosphatidylcholine (PC) in the circulation by phospholipase A2 (PLA2). In the presence of Acyl-CoA, lysophosphatidylcholine acyltransferase (LPCAT) converts LPC to PC, which rapidly gets recycled by the Lands cycle. However, overexpression or enhanced activity of PLA2 increases the LPC content in modified low-density lipoprotein (LDL) and oxidized LDL, which play significant roles in the development of atherosclerotic plaques and endothelial dysfunction. The intracellular enzyme LPCAT cannot directly remove LPC from circulation. Hydrolysis of LPC by autotaxin, an enzyme with lysophospholipase D activity, generates lysophosphatidic acid, which is highly associated with cancers. Although enzymes with lysophospholipase A1 activity could theoretically degrade LPC into harmless metabolites, they have not been found in the circulation. In conclusion, understanding enzyme kinetics and LPC metabolism may help identify novel therapeutic targets in LPC-associated diseases.
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Affiliation(s)
- Shi-Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Mei-Lin Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Division of Thoracic Surgery, Department of Surgery, MacKay Memorial Hospital, MacKay Medical College, Taipei 10449, Taiwan.
| | - Gopal K Marathe
- Department of Studies in Biochemistry, Manasagangothri, University of Mysore, Mysore-570006, India.
| | - Farzana Parveen
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Chu-Huang Chen
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA.
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
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7
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Cao B, Jin M, Brietzke E, McIntyre RS, Wang D, Rosenblat JD, Ragguett RM, Zhang C, Sun X, Rong C, Wang J. Serum metabolic profiling using small molecular water-soluble metabolites in individuals with schizophrenia: A longitudinal study using a pre-post-treatment design. Psychiatry Clin Neurosci 2019; 73:100-108. [PMID: 30156046 DOI: 10.1111/pcn.12779] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 07/24/2018] [Accepted: 08/21/2018] [Indexed: 12/12/2022]
Abstract
AIM We sought to compare alterations in serum bioenergetic markers within a well-characterized sample of adults with schizophrenia at baseline and after 8 weeks of pharmacological treatment with the hypothesis that treatment would be associated with significant changes in bioenergetic markers given the role of bioenergetic dysfunction in schizophrenia. METHODS We recruited adults with schizophrenia (n = 122) who had not received pharmacological treatment for at least 1 month prior to enrollment, including drug-naïve (i.e., first-episode) participants and treatment non-adherent participants. Pre- and post-treatment serum samples were analyzed using liquid chromatography-tandem mass spectrometry. RESULTS Metabolites with the greatest change, when comparing pre- and post-treatment levels, were identified revealing 14 water-soluble metabolites of interest. The composition of these metabolites was: amino acids (n = 6), carnitines (n = 4), polar lipids (n = 3), and organic acid (n = 1). All amino acids and lysophosphatidylcholines (LysoPC) were increased, while the four carnitines - oleoylcarnitine, L-palmitoylcarnitine, linoleyl carnitine, and L-acetylcarnitine - were decreased post-treatment. Of these metabolite biomarkers, six - oleoylcarnitine, linoleyl carnitine, L-acetylcarnitine, LysoPC(15:0), D-glutamic acid, and L-arginine - were identified as having most consistently and predictably changed after 8 weeks of treatment. CONCLUSION The current study identified several bioenergetic markers that consistently change with pharmacological treatment. These bioenergetic changes may provide further insights into the pathophysiology of schizophrenia along with furthering our understanding of the mechanisms subserving both the effects (e.g., antipsychotic effects) and side-effects (e.g., metabolic syndrome) of antipsychotics.
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Affiliation(s)
- Bing Cao
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China
| | - Min Jin
- School of Public Health, Baotou Medical College, Baotou, China
| | - Elisa Brietzke
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Roger S McIntyre
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, Canada.,The Brain and Cognition Discovery Foundation, Toronto, Canada
| | - Dongfang Wang
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China
| | - Joshua D Rosenblat
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Renee-Marie Ragguett
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, Canada
| | | | - Xiaoyu Sun
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China
| | - Carola Rong
- Mood Disorders Psychopharmacology Unit, Toronto Western Hospital, University Health Network, Toronto, Canada
| | - Jingyu Wang
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China.,Beijing Key Laboratory of Toxicological Research and Risk Assessment for Food Safety, Beijing, China
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8
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Tsukahara R, Haniu H, Matsuda Y, Tsukahara T. The AGP-PPARγ axis promotes oxidative stress and diabetic endothelial cell dysfunction. Mol Cell Endocrinol 2018; 473:100-113. [PMID: 29355589 DOI: 10.1016/j.mce.2018.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/21/2017] [Accepted: 01/16/2018] [Indexed: 12/30/2022]
Abstract
Alkyl-glycerophosphate (AGP) accumulates in atherogenic oxidized-LDL and human atherosclerotic plaques and is a potent agonist of peroxisome-proliferator-activated receptor-gamma (PPARγ). Recent studies suggest a potential regulatory role for PPARγ in endothelial nitric oxide synthase (eNOS) expression/activation and nitrogen oxide (NO) generation in the vascular endothelium. Importantly, eNOS-induced NO and advanced glycation end-products (AGEs) are involved in blood-vessel damage, and diabetic patients exhibit high serum NO and AGE levels; however, the effect of AGP on NO- and AGE-mediated endothelium dysfunction remains unknown. Investigation of the AGP-specific effects on NO- and AGE-mediated dysfunction and the underlying molecular mechanisms revealed that AGP upregulated eNOS expression and NO production, and that eNOS silencing and PPARγ antagonism inhibited AGP-mediated eNOS upregulation and NO production. Moreover, AGP-PPARγ-axis-mediated NO production promoted the generation of reactive oxygen species and AGE formation. These results suggested that AGP plays a significant role in the initiation/progression of diabetes-related atherosclerosis through PPARγ activation.
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Affiliation(s)
- Ryoko Tsukahara
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
| | - Hisao Haniu
- Institute for Biomedical Sciences, Shinshu University Interdisciplinary Cluster for Cutting Edge Research 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - Yoshikazu Matsuda
- Clinical Pharmacology Educational Center, Nihon Pharmaceutical University, Ina-machi, Saitama 362-0806, Japan
| | - Tamotsu Tsukahara
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
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Wang Y, Wang Y, Li GR. TRPC1/TRPC3 channels mediate lysophosphatidylcholine-induced apoptosis in cultured human coronary artery smooth muscles cells. Oncotarget 2018; 7:50937-50951. [PMID: 27472391 PMCID: PMC5239449 DOI: 10.18632/oncotarget.10853] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/09/2016] [Indexed: 02/05/2023] Open
Abstract
The earlier study showed that lysophosphatidylcholine (lysoPC) induced apoptosis in human coronary artery smooth muscle cells (SMCs); however, the related molecular mechanisms are not fully understood. The present study investigated how lysoPC induces apoptosis in cultured human coronary artery SMCs using cell viability assay, flow cytometry, confocal microscopy, and molecular biological approaches. We found that lysoPC reduced cell viability in human coronary artery SMCs by eliciting a remarkable Ca2+ influx. The effect was antagonized by La3+, SKF-96365, or Pyr3 as well as by silencing TRPC1 or TRPC3. Co-immunoprecipitation revealed that TRPC1 and TRPC3 had protein-protein interaction. Silencing TRPC1 or TRPC3 countered the lysoPC-induced increase of Ca2+ influx and apoptosis, and the pro-apoptotic proteins Bax and cleaved caspase-3 and decrease of the anti-apoptotic protein Bcl-2 and the survival kinase pAkt. These results demonstrate the novel information that TRPC1/TRPC3 channels mediate lysoPC-induced Ca2+ influx and apoptosis via activating the pro-apoptotic proteins Bax and cleaved caspase-3 and inhibiting the anti-apoptotic protein Bcl-2 and the survival kinase pAkt in human coronary artery SMCs, which implies that TRPC1/TRC3 channels may be the therapeutic target of lysoPC-induced disorders such as atherosclerosis.
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Affiliation(s)
- Yuan Wang
- Xiamen Cardiovascular Hospital, Medical School of Xiamen University, Xiamen, Fujian, China.,Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital, Medical School of Xiamen University, Xiamen, Fujian, China
| | - Gui-Rong Li
- Xiamen Cardiovascular Hospital, Medical School of Xiamen University, Xiamen, Fujian, China.,Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong, China
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10
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Xu X, Gao B, Guan Q, Zhang D, Ye X, Zhou L, Tong G, Li H, Zhang L, Tian J, Huang J. Metabolomic profile for the early detection of coronary artery disease by using UPLC-QTOF/MS. J Pharm Biomed Anal 2016; 129:34-42. [DOI: 10.1016/j.jpba.2016.06.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/14/2016] [Accepted: 06/24/2016] [Indexed: 01/18/2023]
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Mizejewski GJ, Lindau-Shepard B, Pass KA. Newborn screening for autism: in search of candidate biomarkers. Biomark Med 2013; 7:247-60. [PMID: 23547820 DOI: 10.2217/bmm.12.108] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Autism spectrum disorder (ASD) represents a wide range of neurodevelopmental disorders characterized by impairments in social interaction, language, communication and range of interests. Autism is usually diagnosed in children 3-5 years of age using behavioral characteristics; thus, diagnosis shortly after birth would be beneficial for early initiation of treatment. AIM This retrospective study sought to identify newborns at risk for ASD utilizing bloodspot specimens in an immunoassay. MATERIALS & METHODS The present study utilized stored frozen specimens from ASD children already diagnosed at 15-36 months of age. The newborn specimens and controls were analyzed by immunoassay in a multiplex system that included 90 serum biomarkers and subjected to statisical analysis. RESULTS Three sets of five biomarkers associated with ASD were found that differed from control groups. The 15 candidate biomarkers were then discussed regarding their association with ASD. CONCLUSION This study determined that a statistically selected panel of 15 biomarkers successfully discriminated presumptive newborns at risk for ASD from those of nonaffected controls.
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Affiliation(s)
- Gerald J Mizejewski
- Division of Translational Medicine, Wadsworth Center, NYS Department of Health, PO Box 509, Albany, NY 12201 0509, USA.
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12
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Kishta OA, Goldberg P, Husain SNA. Gadolinium chloride attenuates sepsis-induced pulmonary apoptosis and acute lung injury. ISRN INFLAMMATION 2012; 2012:393481. [PMID: 24049647 PMCID: PMC3767356 DOI: 10.5402/2012/393481] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 09/20/2012] [Indexed: 01/11/2023]
Abstract
Gadolinium chloride (GdCl3), a Kupffer cells inhibitor, attenuates acute lung injury; however, the mechanisms behind this effect are not completely elucidated. We tested the hypothesis that GdCl3 acts through the inhibition of lung parenchymal cellular apoptosis. Two groups of rats were injected intraperitoneally with saline or E. coli lipopolysaccharide. In two additional groups, rats were injected with GdCl3 24 hrs prior to saline or LPS administration. At 12 hrs, lung injury, inflammation, and apoptosis were studied. Lung water content, myeloperoxidase activity, pulmonary apoptosis and mRNA levels of interleukin-1β, -2, -5, -6, -10 and TNF-α rose significantly in LPS-injected animals. Pretreatment with GdCl3 significantly reduced LPS-induced elevation of pulmonary water content, myeloperoxidase activity, cleaved caspase-3 intensity, and attenuated pulmonary TUNEL-positive cells. GdCl3 pre-treatment upregulated IL-1β, -2 and -10 pulmonary gene expression without significantly affecting the others. These results suggest that GdCl3 attenuates acute lung injury through its effects on pulmonary parenchymal apoptosis.
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Affiliation(s)
- Osama A Kishta
- Department of Critical Care, Medicine McGill University Health Centre and Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada H3A 1A1
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Kirmizis D, Papagianni A, Dogrammatzi F, Belechri AM, Alexopoulos E, Efstratiadis G, Memmos D. The effects of vitamin E-coated membrane dialyzer compared to simvastatin in patients on chronic hemodialysis. Ren Fail 2012; 34:1135-9. [PMID: 22950641 DOI: 10.3109/0886022x.2012.717484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND We investigated the effects of the use of vitamin E-coated membrane (VEM) dialyzer in comparison to simvastatin on markers of chronic inflammation, oxidative stress, and endothelial cell apoptosis in ten patients on chronic hemodialysis (HD), aiming at distinguishing the different treatment effects and their time sequence on these pathogenetic routes. METHODS Ten HD patients were sequentially submitted to a 6-month treatment with the use of VEM and 10 mg of simvastatin daily, interrupted by a 3-month washout period. At baseline, at 3, and 6 months of each trial, serum C-reactive protein (CRP), apolipoprotein (Apo) A1 and B, lipoprotein-a [Lp(a)], high-sensitivity interleukin-6 (hsIL-6), monocyte chemoattractant protein-1 (MCP-1), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin (sE-selectin), soluble Fas (sFas), soluble Fas ligand (sFasL), and plasma oxidized low-density lipoproteins (oxLDL) levels were determined. RESULTS VEM treatment resulted in a significant decrease in CRP, IL-6, sICAM-1 at 3 months, and oxLDL at 6 months, compared to baseline. Simvastatin resulted in a significant decrease in CRP, which correlated with decreases in both total (r = 0.87, p < 0.05) and low-density lipoprotein cholesterol, IL-6, sICAM-1, sVCAM-1, oxLDL, and sFas at 6 months, compared to baseline. Simvastatin effects on sVCAM-1 (mean difference = 652 ng/mL; 95% CI = 294 to 2686; p < 0.05) and sFas (mean difference = 1284 pg/mL; 95% CI = 510 to 1910; p < 0.05) differed significantly from the corresponding VEM effects. CONCLUSIONS The 6-month use of VEM resulted in more direct and immediate anti-inflammatory effects compared with those caused by the 6-month treatment with simvastatin. Simvastatin caused a more intense decrease in the markers of inflammation, which was in part correlated with its lipid-lowering effects.
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Affiliation(s)
- Dimitrios Kirmizis
- Department of Nephrology, Hippokration General Hospital, Aristotle University, Thessaloniki, Greece.
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14
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Schmitz G, Ruebsaamen K. Metabolism and atherogenic disease association of lysophosphatidylcholine. Atherosclerosis 2009; 208:10-8. [PMID: 19570538 DOI: 10.1016/j.atherosclerosis.2009.05.029] [Citation(s) in RCA: 259] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 04/27/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
Abstract
Lysophosphatidylcholine (LPC) is a major plasma lipid that has been recognized as an important cell signalling molecule produced under physiological conditions by the action of phospholipase A(2) on phosphatidylcholine. LPC transports glycerophospholipid components such as fatty acids, phosphatidylglycerol and choline between tissues. LPC is a ligand for specific G protein-coupled signalling receptors and activates several second messengers. LPC is also a major phospholipid component of oxidized low-density lipoproteins (Ox-LDL) and is implicated as a critical factor in the atherogenic activity of Ox-LDL. Hence, LPC plays an important role in atherosclerosis and acute and chronic inflammation. In this review we focus in some detail on LPC function, biochemical pathways, sources and signal-transduction system. Moreover, we outline the detection of LPC by mass spectrometry which is currently the best method for accurate and simultaneous analysis of each individual LPC species and reveal the pathophysiological implication of LPC which makes it an interesting target for biomarker and drug development regarding atherosclerosis and cardiovascular disorders.
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Affiliation(s)
- Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Regensburg, Germany.
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15
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Cailhier JF, Sirois I, Laplante P, Lepage S, Raymond MA, Brassard N, Prat A, Iozzo RV, Pshezhetsky AV, Hébert MJ. Caspase-3 activation triggers extracellular cathepsin L release and endorepellin proteolysis. J Biol Chem 2008; 283:27220-9. [PMID: 18658137 DOI: 10.1074/jbc.m801164200] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Proteolysis of extracellular matrix components and the production of cryptic bioactive factors play key roles in vascular remodeling. We showed previously that extracellular matrix proteolysis is triggered by the apoptosis of endothelial cells (EC), resulting in the release of an anti-apoptotic C-terminal fragment of endorepellin (LG3). Here, we characterize the endorepellin-cleaving proteases released by apoptotic EC using a multifaceted proteomics strategy. Cathepsin L (CathL), a cysteine protease known to be associated with cardiovascular disease progression in animal models and humans, was isolated from medium conditioned by apoptotic EC. CathL cleaved recombinant endorepellin in vitro, leading to LG3 release. Inhibition of CathL activity in EC exposed to pro-apoptotic stimuli prevented LG3 release without modulating the development of apoptosis in EC. Inhibition of caspase-3 activation in EC with the biochemical inhibitor DEVD-fluoromethyl ketone or small interfering RNAs concomitantly prevented CathL release by EC, LG3 production, and the development of paracrine anti-apoptotic activity. These data demonstrate that caspase-3 activation is a novel pathway of importance for triggering extracellular CathL release and the cleavage of extracellular matrix components.
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Affiliation(s)
- Jean-François Cailhier
- Research Centre, Centre Hospitalier Universitaireé de Montréal and Montreal Cancer Institute Université de Montréal, Montreal, Quebec H2L 4M1, Canada
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16
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Ou HC, Chou FP, Sheu WHH, Hsu SL, Lee WJ. Protective effects of magnolol against oxidized LDL-induced apoptosis in endothelial cells. Arch Toxicol 2007; 81:421-32. [PMID: 17216433 DOI: 10.1007/s00204-006-0172-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 12/04/2006] [Indexed: 01/12/2023]
Abstract
Magnolol, a compound extracted from the Chinese medicinal herb Magnolia officinalis, has several biological effects. However, its protective effects against endothelial injury remain unclear. In this study, we examined whether magnolol prevents oxidized low density lipoprotein (oxLDL)-induced vascular endothelial apoptosis. Incubation of oxLDL with magnolol (2.5-20 microM) inhibited copper-induced oxidative modification via diene formation, thiobarbituric acid reactive substances (TBARS) assay and electrophoretic mobility assay. Apoptotic cell death as characterized by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain. We measured the production of reactive oxygen species (ROS) by using the fluorescent probe 2',7'-dichlorofluorescein acetoxymethyl ester (DCF-AM), and observed the activity of antioxidant enzymes. Furthermore, several apoptotic signaling pathways which showed NF-kappaB activation, increased cytosolic calcium, alteration of mitochondrial membrane potential, cytochrome c release and activation of caspase 3 were also investigated. We demonstrated that magnolol prevented the copper-induced oxidative modification of LDL. Magnolol attenuated the oxLDL-induced ROS generation and subsequent NF-kappaB activation. Furthermore, intracellular calcium accumulation and subsequent mitochondrial membrane potential collapse, cytochome c release and activation of caspase 3 caused by oxLDL were also inhibited by magnolol. Our results suggest that magnolol may have clinical implications in the prevention of atherosclerotic vascular disease through decreasing the oxLDL-induced ROS production.
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Affiliation(s)
- Hsiu-Chung Ou
- Department of Education and Medical Research, Taichung Veterans General Hospital, No. 160, Sec. 3, Taichung-Kang Road, Taichung, 407, Taiwan
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17
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Sudhahar V, Kumar SA, Varalakshmi P. Role of lupeol and lupeol linoleate on lipemic–oxidative stress in experimental hypercholesterolemia. Life Sci 2006; 78:1329-35. [PMID: 16216277 DOI: 10.1016/j.lfs.2005.07.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Accepted: 07/05/2005] [Indexed: 11/16/2022]
Abstract
Epidemiological studies have shown that there is a positive correlation between the incidence of coronary heart disease (CHD) and the blood cholesterol level. To study the effect of plant derived triterpene, lupeol and its ester lupeol linoleate, on blood lipid status and oxidant stress in heart and hemolysate, male albino Wistar rats were fed high cholesterol diet (normal rat chow supplemented with 4% cholesterol and 1% cholic acid; HCD) for 30 days. A significant increase (p<0.05) in plasma total cholesterol (4.22 fold) and triglycerides (1.7 fold) was observed in HCD fed rats, along with elevated LDL (3.56 fold) and VLDL (1.99 fold) cholesterol and decreased HDL cholesterol (34.14%). Treatment with lupeol and its derivative normalized the lipid profile. The significant increase (p<0.05) in lipid peroxidation (LPO) was paralleled by significantly diminished (p<0.05) activities of antioxidant enzymes (SOD, CAT and GPx) and decreased (p<0.05) concentration of antioxidant molecules (GSH, Vit C and Vit E) in cardiac tissue and hemolysate of HCD fed rats. The oxidative tissue injury in hypercholesterolemic rats was substantiated by the increase in cardiac marker, serum CPK and the drop in its activity in the heart tissue. Lupeol and lupeol linoleate treatment decreased the LPO levels and increased enzymatic and nonenzymatic antioxidants. CPK activity in the treated group was comparable with that of the control. These observations highlight the beneficial effects of the triterpene, lupeol and its linoleate ester derivative, in ameliorating the lipidemic-oxidative abnormalities in the early stage of hypercholesterolemic atherosclerosis.
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Affiliation(s)
- Varatharajan Sudhahar
- Department of Medical Biochemistry, Dr. ALM. Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai-600 113, India
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18
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Rakesh K, Agrawal DK. Cytokines and growth factors involved in apoptosis and proliferation of vascular smooth muscle cells. Int Immunopharmacol 2005; 5:1487-506. [PMID: 16023601 DOI: 10.1016/j.intimp.2005.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Revised: 05/09/2005] [Accepted: 05/09/2005] [Indexed: 11/21/2022]
Abstract
This review focuses on the role of cytokines and growth factors involved in the regulation of smooth muscle cells in an atherosclerotic plaque. As a plaque begins to develop, upon endothelial injury inflammatory cells within the lesion interact with the accumulating LDL, other inflammatory cells and smooth muscle cells and release cytokines and growth factors. The mediators released from the activated cells regulate the proliferation and/or survival of smooth muscle cells. This determines the stability and integrity of a plaque. New data emerging from various studies have provided novel insights into many of the cellular interactions and signaling mechanisms involving apoptosis of smooth muscle cells in the atherosclerotic plaques. A number of these studies, focusing on activation of inflammatory cells and the roles of chemokines, cytokines and growth factors, are addressed in this review.
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Affiliation(s)
- Kriti Rakesh
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, United States
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19
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Abstract
A plethora of studies in cultured cells have established that oxidized low-density lipoprotein (oxLDL) may enhance arterial apoptosis that involves both mitochondrial and death receptor pathways (Fas/FasL, TNF receptors I and II), thereby activating caspase cascade and other proteases. When apoptosis is inhibited by Bcl-2 overexpression, oxLDL may trigger necrosis through a calcium-dependent pathway. Despite this effort, the pathophysiological relevance of apoptosis in vivo remains to be elucidated. In principle, apoptosis occurring in atherosclerotic areas could be involved in endothelial cell lining defects, necrotic core formation, and plaque rupture or fissuring. This complex pathogenic framework may favor coronary atherothrombotic events. To date, the pathogenic role of apoptosis in thrombosis is attractive, but a solid evidence is still needed. When the precise role of oxLDL in vascular programmed cell death occurring in vivo is clarified, this may aid in the development of novel therapeutic approaches to adverse atherogenesis and its clinical sequelae.
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Affiliation(s)
- Claudio Napoli
- Department of Medicine, University of Naples, Naples, Italy.
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20
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de Nigris F, Lerman A, Ignarro LJ, Williams-Ignarro S, Sica V, Baker AH, Lerman LO, Geng YJ, Napoli C. Oxidation-sensitive mechanisms, vascular apoptosis and atherosclerosis. Trends Mol Med 2003; 9:351-9. [PMID: 12928037 DOI: 10.1016/s1471-4914(03)00139-4] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Increased generation of oxidants, resulting from disruption of aerobic metabolism and from respiratory burst, is an essential defense mechanism against pathogens and aberrant cells. However, oxidative stress can also trigger and enhance deregulated apoptosis or programmed cell death, characteristic of atherosclerotic lesions. Oxidation-sensitive mechanisms also modulate cellular signaling pathways that regulate vascular expression of cytokines and growth factors, and influence atherogenesis, in particular when increased levels of plasma lipoproteins provide ample substrate for lipid peroxidation and lead to increased formation of adducts with lipoprotein amino acids. In some cases, increased oxidation and apoptosis in a group of cells might be beneficial for survival and function of other groups of arterial cells. However, overall, oxidation and apoptosis appear to promote the progression of diseased arteries towards a lesion that is vulnerable to rupture, and to give rise to myocardial infarction and ischemic stroke. Recent rapid advances in our understanding of the interactions between oxidative stress, apoptosis and arterial gene regulation suggest that selective interventions targeting these biological functions have great therapeutic potential.
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Affiliation(s)
- Filomena de Nigris
- Department of Pharmacological Sciences, University of Salerno, 84084 Salerno, Italy
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21
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Abstract
Traditional thinking accorded a major role to deranged cell proliferation as a determinant of the abnormal cellularity of atheroma. However, studies conducted in several laboratories have documented the occurrence of disordered apoptosis during atherogenesis, leading to the death of lipid-rich foam cells (promoting lipid-core formation) and depletion of vascular smooth muscle cells (fostering fragility of the fibrous cap). A complex interplay of environmental factors and endogenous proteins regulates apoptosis and contributes to the struggle between cell death and procreation in atherosclerosis. In addition to a variety of growth factors, chemically modified lipids, reactive oxygen species, proinflammatory cytokines, and Fas ligand produced by activated immune cells may influence cell viability through a diversity of pathways, including the caspase cascade, the Bcl-2 protein family, and the oncogene/antioncogene system. A clarification of the molecular mechanisms responsible for vascular cell death may aid in the development of novel therapeutic strategies to treat atherosclerosis and its complications, including the acute coronary syndromes.
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Affiliation(s)
- Yong-Jian Geng
- Cardiology Division, Department of Internal Medicine, University of Texas Houston Medical School, USA
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22
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Heinloth A, Brüne B, Fischer B, Galle J. Nitric oxide prevents oxidised LDL-induced p53 accumulation, cytochrome c translocation, and apoptosis in macrophages via guanylate cyclase stimulation. Atherosclerosis 2002; 162:93-101. [PMID: 11947902 DOI: 10.1016/s0021-9150(01)00687-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Oxidatively modified low density lipoprotein (OxLDL) induces apoptosis in vascular cells including macrophages, while NO exerts antiapoptotic effects. Here we studied the impact of nitric oxide (NO) on OxLDL-induced cytochrome c release, apoptosis, and expression of the proapoptotic p53 in macrophages. METHODS Human LDL was oxidised by Cu(2+), and monocytes were prepared from human buffy coats. Differentiation to macrophages was achieved by culturing cells in the presence of human serum and was followed by detecting monocyte chemoattractant protein 1 (MCP-1) expression (RT-PCR). Cytochrome c release and p53 expression of macrophages were detected by immunoblotting, and apoptosis by visualisation of nuclear condensation. RESULTS OxLDL dose-dependently (50-200 microg/ml) induced cytochrome c release that was prevented by preincubation with the NO-donor S-nitrosoglutathione (GSNO) (100 microM) or with the cGMP analogue 8-br-cGMP (100 microM) for 15 h. In cells co-treated with GSNO and the soluble guanylate cyclase (sGC) inhibitor oxadialoquinoxalione (ODQ, 10 microM, 15 h), OxLDL-evoked cytochrome c release remained effective, indicating that NO acted via sGC-dependent cGMP formation. Parallel incubation of macrophages with 8-br-cGMP (100 microM) and ODQ (10 microM) for 15 h left the protective effect of 8-br-cGMP unaltered. Short pre-incubation (30 min) with GSNO or 8-br-cGMP was ineffective in preventing OxLDL-elicited cytochrome c release. Initiation of cytochrome c release in macrophages was paralleled by a dose-dependent accumulation of the proapoptotic factor p53, and by enhanced rate of nuclear condensation. Stabilisation of p53 was prevented by preincubation with the NO-donor GSNO or 8-br-cGMP, thus implying a downmodulatory effect of cGMP on pathways that upregulate the tumor suppressor p53. CONCLUSIONS OxLDL induces cytochrome c release and apoptosis in human macrophages in close association with p53 accumulation. NO attenuates OxLDL-induced cytochrome c release and p53 accumulation via activation of sGC and cGMP formation. These effects may be of particular importance in arterial tissue with reduced NO activity.
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Affiliation(s)
- Alexandra Heinloth
- Department of Medicine, Division of Nephrology, University Hospital of Würzburg, Joseph-Schneider-Strasse 2, 97080 Würzburg, Germany
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23
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Fischer B, von Knethen A, Brüne B. Dualism of oxidized lipoproteins in provoking and attenuating the oxidative burst in macrophages: role of peroxisome proliferator-activated receptor-gamma. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:2828-34. [PMID: 11884452 DOI: 10.4049/jimmunol.168.6.2828] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Activation and deactivation of macrophages are of considerable importance during the development of various disease states, atherosclerosis among others. Macrophage activation is achieved by oxidized lipoproteins (oxLDL) and is determined by oxygen radical (ROS) formation. The oxidative burst was measured by flow cytometry and quantitated by oxidation of the redox-sensitive dye dichlorodihydrofluorescein diacetate. Short-time stimulation dose-dependently elicited ROS formation. Diphenylene iodonium prevented ROS formation, thus pointing to the involvement of a NAD(P)H oxidase in producing reduced oxygen species. In contrast, preincubation of macrophages with oxLDL for 16 h showed an attenuated oxidative burst upon a second contact with oxLDL. Taking into account that oxLDL is an established peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist and considering the anti-inflammatory properties of PPARgamma, we went on and showed that a PPARgamma agonist such as ciglitazone attenuated ROS formation. Along that line, major lipid peroxidation products of oxLDL, such as 9- and 13-hydroxyoctadecadienoic acid, shared that performance. Supporting evidence that PPARgamma activation accounted for reduced ROS generation came from studies in which proliferator-activated receptor response element decoy oligonucleotides, but not a mutated oligonucleotide, supplied in front of oxLDL delivery regained a complete oxidative burst upon cell activation. We conclude that oxLDL not only elicits an oxidative burst upon first contact, but also promotes desensitization of macrophages via activation of PPARgamma. Desensitization of macrophages may have important consequences for the behavior of macrophages/foam cells in atherosclerotic lesions.
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Affiliation(s)
- Barbara Fischer
- Faculty of Biology, Department of Cell Biology, University of Kaiserslautern, Kaiserslautern, Germany
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24
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Choy JC, Granville DJ, Hunt DW, McManus BM. Endothelial cell apoptosis: biochemical characteristics and potential implications for atherosclerosis. J Mol Cell Cardiol 2001; 33:1673-90. [PMID: 11549346 DOI: 10.1006/jmcc.2001.1419] [Citation(s) in RCA: 348] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The high turnover of endothelial cells (EC) in atherosclerosis suggests that an increase in the frequency of both cell proliferation and cell death is important in the pathogenesis of this common disorder. Further, increased apoptosis of EC, smooth muscle cells (SMC) and immune cells has been observed in atheromatous plaques. Many pro-atherogenic factors, including oxidized low-density lipoproteins, angiotensin II and oxidative stress, can induce EC apoptosis. Such damage to the endothelium may be an initiating event in atherogenesis since EC apoptosis may compromise vasoregulation, increase SMC proliferation, SMC migration and blood coagulation. In addition, EC overlying vascular lesions have been shown to increase their expression of pro-apoptotic proteins, such as Fas and Bax, while decreasing levels of anti-apoptotic factors. Therefore, understanding EC apoptotic pathways that are altered in atherosclerosis may enable a greater understanding of disease pathogenesis and foster the development of new therapies. The present discussion outlines the biochemical characteristics of EC apoptosis and the role that altered regulation of apoptosis plays in vasculopathy.
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Affiliation(s)
- J C Choy
- UBC McDonald Research Laboratories/The iCAPTUR4E Centre, Department of Pathology and Laboratory Medicine, St. Paul's Hospital/Providence Health Care-University of British Columbia, Vancouver, BC, Canada
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25
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Heermeier K, Leicht W, Palmetshofer A, Ullrich M, Wanner C, Galle J. Oxidized LDL suppresses NF-kappaB and overcomes protection from apoptosis in activated endothelial cells. J Am Soc Nephrol 2001; 12:456-463. [PMID: 11181793 DOI: 10.1681/asn.v123456] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory disease associated with enhanced apoptotic cell death in vascular cells, partly induced by oxidized low-density lipoprotein (OxLDL). However, proinflammatory stimuli such as lipopolysaccharide (LPS) or tumor necrosis factor-alpha (TNF-alpha) activate endothelial cells (EC) and inhibit apoptosis through induction of nuclear factor kappaB (NF-kappaB)-dependent genes. This study therefore investigated whether OxLDL or its component, lysophosphatidylcholine (LPC), interacts with the effect of LPS or TNF-alpha on cell survival. Human EC were incubated with LPS, TNF-alpha, OxLDL, or LPC alone or in combinations. OxLDL (100 to 200 microg/ml) and LPC (100 to 300 microM) induced apoptosis dose-dependently. LPS and TNF-alpha had no effect on cell survival in the presence or absence of OxLDL or LPC. LPS and TNF-alpha both induced the antiapoptotic gene A20, whereas OxLDL and LPC suppressed its induction. Expression of A20 is regulated by NF-kappaB. OxLDL and LPC dose-dependently suppressed NF-kappaB activity. For functional analysis, bovine EC were transfected with A20 encoding expression constructs in sense and antisense orientation. Bovine EC that overexpressed A20 were protected against OxLDL-induced apoptosis, whereas expression of antisense A20 rendered cells more sensitive to OxLDL. These results suggest that OxLDL not only induces cell death, as has been shown before, but also compromises antiapoptotic protection of activated EC. OxLDL sensitizes EC to apoptotic triggers by interfering with the induction of A20 during the inflammatory response seen in atherosclerotic lesions. This inhibition is based on repression of NF-kappaB activation. The effect may be caused by the OxLDL component LPC.
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Affiliation(s)
- Kathrin Heermeier
- University Hospital, Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
| | - Wolfgang Leicht
- University Hospital, Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
| | - Alois Palmetshofer
- Institute of Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Markus Ullrich
- University Hospital, Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
| | - Christoph Wanner
- University Hospital, Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
| | - Jan Galle
- University Hospital, Department of Medicine, Division of Nephrology, University of Würzburg, Würzburg, Germany
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Abstract
The oxidation of LDL is thought to be a major contributor to the development of atherosclerosis. Considerable descriptive evidence has been accumulated showing that oxidized LDL promotes pro-atherogenic events. However, direct evidence that oxidized LDL causes atherosclerosis is lacking. This article summarizes the results of recent studies that demonstrate how oxidized LDL affects cellular function, and highlights key issues that should be addressed to link LDL oxidation with atherosclerosis.
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Affiliation(s)
- M J Thomas
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016, USA.
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