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Dai W, Castleberry M, Zheng Z. Tale of two systems: the intertwining duality of fibrinolysis and lipoprotein metabolism. J Thromb Haemost 2023; 21:2679-2696. [PMID: 37579878 PMCID: PMC10599797 DOI: 10.1016/j.jtha.2023.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 08/16/2023]
Abstract
Fibrinolysis is an enzymatic process that breaks down fibrin clots, while dyslipidemia refers to abnormal levels of lipids and lipoproteins in the blood. Both fibrinolysis and lipoprotein metabolism are critical mechanisms that regulate a myriad of functions in the body, and the imbalance of these mechanisms is linked to the development of pathologic conditions, such as thrombotic complications in atherosclerotic cardiovascular diseases. Accumulated evidence indicates the close relationship between the 2 seemingly distinct and complicated systems-fibrinolysis and lipoprotein metabolism. Observational studies in humans found that dyslipidemia, characterized by increased blood apoB-lipoprotein and decreased high-density lipoprotein, is associated with lower fibrinolytic potential. Genetic variants of some fibrinolytic regulators are associated with blood lipid levels, supporting a causal relationship between these regulators and lipoprotein metabolism. Mechanistic studies have elucidated many pathways that link the fibrinolytic system and lipoprotein metabolism. Moreover, profibrinolytic therapies improve lipid panels toward an overall cardiometabolic healthier phenotype, while some lipid-lowering treatments increase fibrinolytic potential. The complex relationship between lipoprotein and fibrinolysis warrants further research to improve our understanding of the bidirectional regulation between the mediators of fibrinolysis and lipoprotein metabolism.
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Affiliation(s)
- Wen Dai
- Versiti Blood Research Institute, Milwaukee, USA.
| | | | - Ze Zheng
- Versiti Blood Research Institute, Milwaukee, USA; Department of Medicine, Medical College of Wisconsin, Milwaukee, USA; Cardiovascular Center, Medical College of Wisconsin, Milwaukee, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, USA.
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Singh A, Kaur A, Stephens C, Fekete I, Nelson J, Kodwani N. Pulmonary haemorrhage and extensive arterial thrombosis with anabolic steroid abuse. BMJ Case Rep 2023; 16:e254817. [PMID: 37640416 PMCID: PMC10462977 DOI: 10.1136/bcr-2023-254817] [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: 08/31/2023] Open
Abstract
Anabolic-androgenic steroids (AASs) are commonly implicated in thromboembolic events but rarely cause diffuse alveolar haemorrhage. We report the case of a Caucasian man in his late 40s who was consuming supratherapeutic doses of AAS and presented with shortness of breath and haemoptysis. Chest imaging showed bilateral patchy infiltrates in the lungs with diffuse blood throughout the airways on bronchoscopy. Extensive infectious and autoimmune workup were unremarkable. The patient then developed right foot ischaemia and was found to have extensive aortic and bilateral lower extremity arterial thrombosis. Anticoagulation was attempted despite haemoptysis. Thrombectomy procedures were unsuccessful and the patient eventually developed worsening rhabdomyolysis requiring intubation and bilateral amputation. His clinical condition continued to worsen and he passed away 10 days after admission. This case highlights the rare synchronous occurrence of two life-threatening complications secondary to anabolic steroid abuse which can pose a significant diagnostic and therapeutic challenge for clinicians.
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Affiliation(s)
- Angad Singh
- Internal Medicine, HCA MidAmerica DIvision, Kansas City, Kansas, USA
| | - Anahat Kaur
- Hematology and Medical Oncology, Albert Einstein College of Medicine D Samuel Gottesman Library, Bronx, New York, USA
| | - Corbin Stephens
- Internal Medicine, HCA MidAmerica DIvision, Kansas City, Kansas, USA
| | - Ian Fekete
- Internal Medicine, HCA MidAmerica DIvision, Kansas City, Kansas, USA
| | - John Nelson
- Internal Medicine, HCA MidAmerica DIvision, Kansas City, Kansas, USA
| | - Naresh Kodwani
- Internal Medicine, HCA MidAmerica DIvision, Kansas City, Kansas, USA
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Ma J, Qin J, Hu J, Shang M, Zhou Y, Liang N, Zhang Y, Zhu Y. Incidence and Hematological Biomarkers Associated With Preoperative Deep Venous Thrombosis Following Foot Fractures. Foot Ankle Int 2020; 41:1563-1570. [PMID: 32806946 DOI: 10.1177/1071100720943844] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND This study was designed to investigate the incidence and hematological biomarker levels that are associated with deep venous thrombosis (DVT) following closed foot fractures (except calcaneal fractures). METHODS A retrospective analysis of data on patients presenting with closed foot fractures (excluding the calcaneus) between October 2014 and December 2018 was conducted. Duplex ultrasonography was used to screen preoperative DVT of bilateral lower extremities. Data on demographics, comorbidities, types of fracture, and laboratory biomarkers at admission were collected. Univariate analyses and multivariate logistic regression analyses were carried out to determine the independent risk factors associated with DVT. RESULTS A total of 537 patients were included, among whom 28 patients had preoperative DVTs, indicating a crude incidence rate of 5.2%. In isolated closed foot fractures, DVT occurred in 12 (2.9%) out of 410 patients, while in patients with concurrent fracture in other locations, 16 (12.6%) out of 127 patients developed DVT. The average interval between fracture occurrence and diagnosis of DVT was 4.2 days (median, 2 days), ranging from 0 to 17 days. Twenty-four patients (85.7%) developed DVT in the injured extremity, 3 (10.7%) in the uninjured extremity, and 1 (3.5%) in bilateral extremities. Seven risk factors were identified to be associated with DVT, including alcohol consumption, concomitant other fractures, platelet distribution width (PDW) <12%, high-density lipoprotein cholesterol (HDL-C) <1.1mmol/L, serum alkaline phosphatase (ALP) >100 U/L, serum sodium concentration (Na+) <135 mmol/L, and D-dimer >0.5 mg/L. CONCLUSION Being aware of the prevalence of DVT in closed foot fractures can help physicians to carry out the overall assessment, risk stratification, and individual prevention programs. LEVEL OF EVIDENCE Level III, a prospective cohort study.
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Affiliation(s)
- Jiangtao Ma
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Jin Qin
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Jinglve Hu
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Meishuang Shang
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Yali Zhou
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Ningxi Liang
- Hebei Orthopedic Clinical Research Center, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Orthopaedic Institution of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
| | - Yingze Zhang
- Department of Orthopaedic Surgery, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Chinese Academy of Engineering, Beijing, People's Republic of China
| | - Yanbin Zhu
- Department of Orthopaedic Surgery, the 3rd Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.,Key Laboratory of Biomechanics of Hebei Province, Shijiazhuang, Hebei, People's Republic of China
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Scipione CA, Koschinsky ML, Boffa MB. Lipoprotein(a) in clinical practice: New perspectives from basic and translational science. Crit Rev Clin Lab Sci 2017; 55:33-54. [PMID: 29262744 DOI: 10.1080/10408363.2017.1415866] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Elevated plasma concentrations of lipoprotein(a) (Lp(a)) are a causal risk factor for coronary heart disease (CHD) and calcific aortic valve stenosis (CAVS). Genetic, epidemiological and in vitro data provide strong evidence for a pathogenic role for Lp(a) in the progression of atherothrombotic disease. Despite these advancements and a race to develop new Lp(a) lowering therapies, there are still many unanswered and emerging questions about the metabolism and pathophysiology of Lp(a). New studies have drawn attention to Lp(a) as a contributor to novel pathogenic processes, yet the mechanisms underlying the contribution of Lp(a) to CVD remain enigmatic. New therapeutics show promise in lowering plasma Lp(a) levels, although the complete mechanisms of Lp(a) lowering are not fully understood. Specific agents targeted to apolipoprotein(a) (apo(a)), namely antisense oligonucleotide therapy, demonstrate potential to decrease Lp(a) to levels below the 30-50 mg/dL (75-150 nmol/L) CVD risk threshold. This therapeutic approach should aid in assessing the benefit of lowering Lp(a) in a clinical setting.
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Affiliation(s)
- Corey A Scipione
- a Department of Advanced Diagnostics , Toronto General Hospital Research Institute, UHN , Toronto , Canada
| | - Marlys L Koschinsky
- b Robarts Research Institute , Western University , London , Canada.,c Department of Physiology & Pharmacology , Schulich School of Medicine & Dentistry, Western University , London , Canada
| | - Michael B Boffa
- d Department of Biochemistry , Western University , London , Canada
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Kotani K, Sahebkar A, Serban MC, Ursoniu S, Mikhailidis DP, Mariscalco G, Jones SR, Martin S, Blaha MJ, Toth PP, Rizzo M, Kostner K, Rysz J, Banach M. Lipoprotein(a) Levels in Patients With Abdominal Aortic Aneurysm. Angiology 2016; 68:99-108. [PMID: 26980774 DOI: 10.1177/0003319716637792] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Circulating markers relevant to the development of abdominal aortic aneurysm (AAA) are currently required. Lipoprotein(a), Lp(a), is considered a candidate marker associated with the presence of AAA. The present meta-analysis aimed to evaluate the association between circulating Lp(a) levels and the presence of AAA. The PubMed-based search was conducted up to April 30, 2015, to identify the studies focusing on Lp(a) levels in patients with AAA and controls. Quantitative data synthesis was performed using a random effects model, with standardized mean difference (SMD) and 95% confidence interval (CI) as summary statistics. Overall, 9 studies were identified. After a combined analysis, patients with AAA were found to have a significantly higher level of Lp(a) compared to the controls (SMD: 0.87, 95% CI: 0.41-1.33, P < .001). This result remained robust in the sensitivity analysis, and its significance was not influenced after omitting each of the included studies from the meta-analysis. The present meta-analysis confirmed a higher level of circulating Lp(a) in patients with AAA compared to controls. High Lp(a) levels can be associated with the presence of AAA, and Lp(a) may be a marker in screening for AAA. Further studies are needed to establish the clinical utility of measuring Lp(a) in the prevention and management of AAA.
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Affiliation(s)
- Kazuhiko Kotani
- 1 Division of Community and Family Medicine, Jichi Medical University, Shimotsuke-City, Japan
| | - Amirhossein Sahebkar
- 2 Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,3 Metabolic Research Centre, Royal Perth Hospital, School of Medicine and Pharmacology, University of Western Australia, Perth, Australia
| | - Maria-Corina Serban
- 4 Discipline of Pathophysiology, Department of Functional Sciences, "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
| | - Sorin Ursoniu
- 5 Discipline of Public Health, Department of Functional Sciences, "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
| | - Dimitri P Mikhailidis
- 6 Department of Clinical Biochemistry, Royal Free Campus, University College London Medical School, University College London, London, United Kingdom
| | - Giovanni Mariscalco
- 7 Department of Cardiovascular Sciences, University of Leicester Glenfield Hospital, Leicester, United Kingdom
| | - Steven R Jones
- 8 The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Seth Martin
- 8 The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Michael J Blaha
- 8 The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Peter P Toth
- 8 The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA.,9 Preventive Cardiology, CGH Medical Center, Sterling, IL, USA
| | - Manfredi Rizzo
- 10 Biomedical Department of Internal Medicine and Medical Specialties, University of Palermo, Italy
| | - Karam Kostner
- 11 Mater Hospital, University of Queensland, St Lucia, Australia
| | - Jacek Rysz
- 12 Department of Hypertension, Nephrology and Hypertension, WAM University Hospital in Lodz, Medical University of Lodz, Poland
| | - Maciej Banach
- 12 Department of Hypertension, Nephrology and Hypertension, WAM University Hospital in Lodz, Medical University of Lodz, Poland
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7
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Lipoprotein(a): Cellular Effects and Molecular Mechanisms. CHOLESTEROL 2012; 2012:923289. [PMID: 22991657 PMCID: PMC3443569 DOI: 10.1155/2012/923289] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 07/24/2012] [Indexed: 01/31/2023]
Abstract
Lipoprotein(a) (Lp(a)) is an independent risk factor for the development of cardiovascular disease (CVD). Indeed, individuals with plasma concentrations >20 mg/dL carry a 2-fold increased risk of developing CVD, accounting for ~25% of the population. Circulating levels of Lp(a) are remarkably resistant to common lipid lowering therapies, and there are currently no robust treatments available for reduction of Lp(a) apart from plasma apheresis, which is costly and labour intensive. The Lp(a) molecule is composed of two parts, an LDL/apoB-100 core and a unique glycoprotein, apolipoprotein(a) (apo(a)), both of which can interact with components of the coagulation cascade, inflammatory pathways, and cells of the blood vessel wall (smooth muscle cells (SMC) and endothelial cells (EC)). Therefore, it is of key importance to determine the molecular pathways by which Lp(a) exerts its influence on the vascular system in order to design therapeutics to target its cellular effects. This paper will summarise the role of Lp(a) in modulating cell behaviour in all aspects of the vascular system including platelets, monocytes, SMC, and EC.
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Delluc A, Tromeur C, Mottier D, Lacut K. Lipid parameters and venous thromboembolism: clinical evidence, pathophysiology and therapeutic implications. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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9
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Balogh E, Bereczky Z, Katona E, Koszegi Z, Edes I, Muszbek L, Czuriga I. Interaction between homocysteine and lipoprotein(a) increases the prevalence of coronary artery disease/myocardial infarction in women: a case-control study. Thromb Res 2011; 129:133-8. [PMID: 21803402 DOI: 10.1016/j.thromres.2011.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 06/29/2011] [Accepted: 07/05/2011] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Our aim was to investigate the association of elevated homocysteine (Hcy) and lipoprotein(a) Lp(a) with the prevalence of coronary artery disease (CAD) and myocardial infarction (MI) and to investigate their interaction in both genders. MATERIALS AND METHODS 955 (male/female: 578/377) consecutive patients admitted for coronary angiography were enrolled in the study. Lp(a), Hcy, vitamin B12, folic acid, MTHFR C677T polymorphism and traditional risk factors were determined. RESULTS 619 patients had significant (≥50%) stenosis (CAD+) and 341 had MI (MI+). CAD-MI- cases (n=302) were considered as controls. Adjusted Hcy levels were significantly elevated only in the female CAD+MI+group that was related to decreased vitamin B12 levels. Lp(a) was elevated in the CAD+MI+group of both genders. Folic acid levels and MTHFR T677 allele frequency did not show significant difference. Moderate hyperhomocysteinemia (Hcy >15μmol/L) or elevated Lp(a) (>300mg/L) increased the risk of CAD (OR 2.27, CI 1.36-3.80 and OR 1.64, CI 1.03-2.61, respectively) and MI (OR 2.52, CI 1.36-4.67 and OR 1.89, CI 1.06-3.38, respectively) only in women. Only simultaneous but not isolated elevation of Hcy and Lp(a) conferred a significant, 3.6-fold risk of CAD in females and even higher (11-fold) risk in young females, which suggested an interactive effect. CONCLUSIONS Moderate hyperhomocysteinemia or elevated Lp(a) level associated with a risk of CAD and MI only in women. While isolated elevation of one of the two parameters represented a mild risk of CAD, their combined elevation highly increased the risk in females. No such effect was observed in males.
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Affiliation(s)
- Emilia Balogh
- Department of Cardiology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
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10
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Abstract
PURPOSE OF REVIEW To provide an update of the literature describing the link between lipoprotein a and vascular disease. RECENT FINDINGS There is evidence that elevated plasma lipoprotein a levels are associated with coronary heart disease, stroke and other manifestations of atherosclerosis. Several mechanisms may be implicated, including proinflammatory actions and impaired fibrinolysis. SUMMARY Lipoprotein a potentially represents a useful tool for risk stratification in the primary and secondary prevention setting. However, there are still unresolved methodological issues regarding the measurement of lipoprotein a levels. Targeting lipoprotein a in order to reduce vascular risk is hampered by the lack of well tolerated and effective pharmacological interventions. Moreover, it has not yet been established whether such a reduction will result in fewer vascular events. The risk attributed to lipoprotein a may be reduced by aggressively tackling other vascular risk factors, such as low-density lipoprotein cholesterol.
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Abstract
Peripheral arterial disease (PAD), a relatively common manifestation of atherosclerotic vascular disease, is associated with significant morbidity and mortality. Although conventional risk factors contribute to the onset and progression of PAD, the role of 'novel' biomarkers in pathways of inflammation, thrombosis, lipoprotein metabolism, and oxidative stress in determining susceptibility to PAD is being increasingly recognized. Validation of novel risk factors for PAD may allow earlier detection, an improved understanding of disease etiology and progression, and the development of new therapies. In this review, we discuss available evidence for associations between novel circulating markers and several aspects of PAD including disease susceptibility, progression, functional limitation, and adverse outcomes.
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Affiliation(s)
- Farhan J Khawaja
- Department of Medicine, Division of Cardiovascular Diseases and the Gonda Vascular Center, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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Beyond high-density lipoprotein cholesterol levels evaluating high-density lipoprotein function as influenced by novel therapeutic approaches. J Am Coll Cardiol 2008; 51:2199-211. [PMID: 18534265 DOI: 10.1016/j.jacc.2008.03.016] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 02/19/2008] [Accepted: 03/04/2008] [Indexed: 02/02/2023]
Abstract
A number of therapeutic strategies targeting high-density lipoprotein (HDL) cholesterol and reverse cholesterol transport are being developed to halt the progression of atherosclerosis or even induce regression. However, circulating HDL cholesterol levels alone represent an inadequate measure of therapeutic efficacy. Evaluation of the potential effects of HDL-targeted interventions on atherosclerosis requires reliable assays of HDL function and surrogate markers of efficacy. Promotion of macrophage cholesterol efflux and reverse cholesterol transport is thought to be one of the most important mechanisms by which HDL protects against atherosclerosis, and methods to assess this pathway in vivo are being developed. Indexes of monocyte chemotaxis, endothelial inflammation, oxidation, nitric oxide production, and thrombosis reveal other dimensions of HDL functionality. Robust, reproducible assays that can be performed widely are needed to move this field forward and permit effective assessment of the therapeutic potential of HDL-targeted therapies.
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Hoover-Plow J, Shchurin A, Hart E, Sha J, Hill AE, Singer JB, Nadeau JH. Genetic background determines response to hemostasis and thrombosis. BMC HEMATOLOGY 2006; 6:6. [PMID: 17022820 PMCID: PMC1617083 DOI: 10.1186/1471-2326-6-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Accepted: 10/05/2006] [Indexed: 11/25/2022]
Abstract
Background Thrombosis is the fatal and disabling consequence of cardiovascular diseases, the leading cause of mortality and morbidity in Western countries. Two inbred mouse strains, C57BL/6J and A/J, have marked differences in susceptibility to obesity, atherosclerosis, and vessel remodeling. However, it is unclear how these diverse genetic backgrounds influence pathways known to regulate thrombosis and hemostasis. The objective of this study was to evaluate thrombosis and hemostasis in these two inbred strains and determine the phenotypic response of A/J chromosomes in the C57BL/6J background. Methods A/J and C57Bl/6J mice were evaluated for differences in thrombosis and hemostasis. A thrombus was induced in the carotid artery by application of the exposed carotid to ferric chloride and blood flow measured until the vessel occluded. Bleeding and rebleeding times, as surrogate markers for thrombosis and hemostasis, were determined after clipping the tail and placing in warm saline. Twenty-one chromosome substitution strains, A/J chromosomes in a C57BL/6J background, were screened for response to the tail bleeding assay. Results Thrombus occlusion time was markedly decreased in the A/J mice compared to C57BL/6J mice. Tail bleeding time was similar in the two strains, but rebleeding time was markedly increased in the A/J mice compared to C57BL/6J mice. Coagulation times and tail morphology were similar, but tail collagen content was higher in A/J than C57BL/6J mice. Three chromosome substitution strains, B6-Chr5A/J, B6-Chr11A/J, and B6-Chr17A/J, were identified with increased rebleeding time, a phenotype similar to A/J mice. Mice heterosomic for chromosomes 5 or 17 had rebleeding times similar to C57BL/6J mice, but when these two chromosome substitution strains, B6-Chr5A/J and B6-Chr17A/J, were crossed, the A/J phenotype was restored in these doubly heterosomic progeny. Conclusion These results indicate that susceptibility to arterial thrombosis and haemostasis is remarkably different in C57BL/and A/J mice. Three A/J chromosome substitution strains were identified that expressed a phenotype similar to A/J for rebleeding, the C57Bl/6J background could modify the A/J phenotype, and the combination of two A/J QTL could restore the phenotype. The diverse genetic backgrounds and differences in response to vascular injury induced thrombosis and the tail bleeding assay, suggest the potential for identifying novel genetic determinants of thrombotic risk.
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Affiliation(s)
- Jane Hoover-Plow
- Department of Cardiovascular Medicine, Joseph J. Jacobs Center for Thrombosis and Vascular Biology, Department of Molecular Cardiology, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, USA
| | - Aleksey Shchurin
- Department of Cardiovascular Medicine, Joseph J. Jacobs Center for Thrombosis and Vascular Biology, Department of Molecular Cardiology, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, USA
| | - Erika Hart
- Department of Cardiovascular Medicine, Joseph J. Jacobs Center for Thrombosis and Vascular Biology, Department of Molecular Cardiology, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, USA
| | - Jingfeng Sha
- Department of Cardiovascular Medicine, Joseph J. Jacobs Center for Thrombosis and Vascular Biology, Department of Molecular Cardiology, Cleveland Clinic Lerner Research Institute, Cleveland, Ohio, USA
| | - Annie E Hill
- Department of Genetics, Case University School of Medicine, Cleveland, Ohio, USA
| | - Jonathan B Singer
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, USA
| | - Joseph H Nadeau
- Department of Genetics, Case University School of Medicine, Cleveland, Ohio, USA
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Jovin IS, Müller-Berghaus G. Interrelationships between the fibrinolytic system and lipoproteins in the pathogenesis of coronary atherosclerosis. Atherosclerosis 2004; 174:225-33. [PMID: 15136052 DOI: 10.1016/j.atherosclerosis.2004.01.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Revised: 01/08/2004] [Accepted: 01/14/2004] [Indexed: 11/22/2022]
Abstract
The fibrinolytic system is comprised of a series of serine proteases and serine protease inhibitors which are involved in the dissolution of fibrin in the vascular lumen, but also in the migration of cells and in the remodeling of the extracellular matrix of the vascular wall. The transcription, expression and degradation of the various fibrinolytic enzymes by cells in the vascular wall is influenced by lipoproteins and this interrelationship may play a significant role in the development of the atherosclerotic plaque: the transcription of plasminogen activator inhibitor-1 is influenced by very low-density lipoproteins, the expression of both tissue plasminogen activator and plasminogen activator inhibitor-1 is influenced by low-density lipoproteins and lipoprotein(a) (Lp(a)) and the internalization of the urokinase: plasminogen activator inhibitor-1 complex occurs via the low-density lipoprotein related protein. Several clinical studies have shown correlations between fibrinolytic parameters and lipoproteins in healthy populations and in patients with dyslipidemia, but the correlation between single plasma fibrinolytic enzymes and the severity of coronary atherosclerosis is less well documented. The reduction of plasma lipids with lipid-lowering drugs also affects the concentration of fibrinolytic enzymes, although this may also be due to direct effects of the drugs on the expression of the various fibrinolytic enzymes. The reduction of fibrinolytic and proteolytic activity in the atherosclerotic plaque by their lipid-lowering effect and by their direct action on the fibrinolytic system may be one of the mechanisms by which some lipid-lowering drugs achieve plaque stabilization.
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Affiliation(s)
- Ion S Jovin
- Department of Hemostaseology and Transfusion Medicine, Kerckhoff-Klinik, Bad Nauheim, Germany.
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Sciacca FL, Ciusani E, Silvani A, Corsini E, Frigerio S, Pogliani S, Parati E, Croci D, Boiardi A, Salmaggi A. Genetic and Plasma Markers of Venous Thromboembolism in Patients with High Grade Glioma. Clin Cancer Res 2004; 10:1312-7. [PMID: 14977830 DOI: 10.1158/1078-0432.ccr-03-0198] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Deep venous thrombosis/pulmonary embolism (DVT/PE) is a frequent complication in the course of cancer, particularly in brain tumors. We investigated genetic and plasma factors possibly associated with risk of DVT/PE in patients with high-grade glioma. EXPERIMENTAL DESIGN In a case-control study, we studied polymorphisms of the genes coding for factor II (G20210A), factor V (G1691A), methylenetetrahydrofolate-reductase (C677T), tissue-type plasminogen activator (tPA; insertion/deletion), plasminogen activator inhibitor-1 (PAI-1; 4G/5G), and vascular endothelial growth factor (VEGF; C936T). We also measured plasma levels of D-dimer, lipoprotein (lp) (a), homocysteine, VEGF, tPA, and PAI-1, comparing healthy control patients with patients with glioma or with patients with neurological nonneoplastic disease (multiple sclerosis). RESULTS Genotype frequencies of polymorphisms analyzed were similar in patients with glioma and in healthy matched population. D-dimer, lp (a), homocysteine, VEGF, tPA, and PAI-1 plasma levels were significantly higher in patients with glioma than in healthy controls, whereas patients having neurological nonneoplastic disease had plasma values of these molecules not significantly different from healthy controls. VEGF, tPA, and PAI-1 were also found at high-plasma levels in patients carrying genotypes that, in healthy controls, were associated with "low-producing" phenotypes. CONCLUSIONS Genetic risk factors alone did not explain the high incidence of DVT/PE observed in patients with glioma. Higher plasma levels of molecules influencing the coagulation pathways indicate that the tumor itself might confer an increased risk of DVT/PE; thus, D-dimer, homocysteine, lp (a), VEGF, tPA, and PAI-1 look like good candidates to be evaluated as DVT/PE prognostic factors.
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Petersen E, Wågberg F, Angquist KA. Does Lipoprotein(a) Inhibit Elastolysis in Abdominal Aortic Aneurysms? Eur J Vasc Endovasc Surg 2003; 26:423-8. [PMID: 14512007 DOI: 10.1016/s1078-5884(03)00178-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE to test the hypothesis that there is a negative association between serum levels of lipoprotein(a) (Lp(a)) and elastin-derived peptides (EDP) as well as matrix metalloproteinase (MMP)-9 activation in the aneurysm wall in patients with asymptomatic abdominal aortic aneurysms (AAA). MATERIAL AND METHODS from 30 patients operated for asymptomatic AAAs, preoperative serum samples and AAA biopsies were collected. Lp(a) (mg/L) and EDP (ng/ml) in serum were measured by enzyme linked immunosorbent assays. MMP-9 activity (arbitrary units) in the AAA wall was measured by gelatin zymography and the ratio: active MMP-9/total MMP-9 were calculated. RESULTS there was a significant negative correlation (Spearman's rho) between serum levels of Lp(a) and EDP (r= -0.707, p<0.001), as well as the share of activated MMP-9 (r= -0.461, p=0.01) in the AAA wall. CONCLUSION this preliminary study indicate that Lp(a) inhibit elastolysis in asymptomatic AAA.
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Affiliation(s)
- E Petersen
- Department of Surgery, Umeå University Hospital, Umeå, Sweden
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19
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Abstract
Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.
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Affiliation(s)
- Giuseppe Lippi
- Istituto di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologiche e Biomediche, Università degli Studi di Verona, Verona, Italy
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20
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Nofer JR, Kehrel B, Fobker M, Levkau B, Assmann G, von Eckardstein A. HDL and arteriosclerosis: beyond reverse cholesterol transport. Atherosclerosis 2002; 161:1-16. [PMID: 11882312 DOI: 10.1016/s0021-9150(01)00651-7] [Citation(s) in RCA: 432] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inverse correlation between serum levels of high density lipoprotein (HDL) cholesterol and the risk of coronary heart disease, the protection of susceptible animals from atherosclerosis by transgenic manipulation of HDL metabolism, and several potentially anti-atherogenic in vitro-properties have made HDL metabolism an interesting target for pharmacological intervention in atheroslcerosis. We have previously reviewed the concept of reverse cholesterol transport, which describes both the metabolism and the classic anti-atherogenic function of HDL (Arterioscler. Thromb. Vasc. Biol. 20 2001 13). We here summarize the current understanding of additional biological, potentially anti-atherogenic properties of HDL. HDL inhibits the chemotaxis of monocytes, the adhesion of leukocytes to the endothelium, endothelial dysfunction and apoptosis, LDL oxidation, complement activation, platelet activation and factor X activation but also stimulates the proliferation of endothelial cells and smooth muscle cells, the synthesis of prostacyclin and natriuretic peptide C in endothelial cells, and the activation of proteins C and S. These anti-inflammatory, anti-oxidative, anti-aggregatory, anti-coagulant, and pro-fibrinolytic activities are exerted by different components of HDL, namley apolipoproteins, enzymes, and even specific phospholipids. This complexity further emphasizes that changes in the functionality of HDL rather than changes of plasma HDL-cholesterol levels determine the anti-atherogenicity of therapeutic alterations of HDL metabolism.
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Affiliation(s)
- Jerzy-Roch Nofer
- Institut für Klinische Chemie und Laboratoriumsmedizin, Westfälische Wilhelms-Universität, Albert Schweitzer Str. 33, 48129 Münster, Germany.
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21
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22
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Klezovitch O, Edelstein C, Scanu AM. Stimulation of interleukin-8 production in human THP-1 macrophages by apolipoprotein(a). Evidence for a critical involvement of elements in its C-terminal domain. J Biol Chem 2001; 276:46864-9. [PMID: 11591715 DOI: 10.1074/jbc.m107943200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the vessel wall, macrophages are among the cells that upon activation contribute to the atherosclerotic process. Low density lipoproteins (LDL) can mediate this activation but only after enzymatic or oxidative modification. Lipoprotein(a) (Lp(a)) is an LDL variant that has been shown to have an atherogenic potential by no clearly established mechanisms. In the present study we examined whether native Lp(a) can activate macrophages and, if so, identify the structural elements involved in this action. For this purpose, we utilized human THP-1 macrophages, prepared by treating THP-1 monocytes with phorbol ester, and we exposed them to Lp(a) and its two derivatives, apo(a)-free LDL (Lp(a-)) and free apo(a). We also studied apo(a) fragments, F1 (N terminus) and F2 (C terminus) and subfragments thereof, obtained by leukocyte elastase digestion. By Northern blot analyses, Lp(a), but not Lp(a-), caused up to a 12-fold increase in interleukin 8 (IL-8) mRNA as compared with untreated cells. Free apo(a) also induced the production of IL-8 mRNA; however, the effect was 3-4-fold higher than that of Lp(a). The increase in mRNA was associated with the accumulation of IL-8 protein in the culture medium. F1 had only a minimal effect, whereas F2 was 1.5-2-fold more potent than apo(a), an activity mostly contained in the Kringle V-protease region. A monoclonal antibody specific for Kringle V inhibited the apo(a)-mediated effect on IL-8. We conclude that Lp(a) via elements contained in the C-terminal domain of apo(a) causes in THP-1 macrophages an increased production of IL-8, a chemokine with pro-inflammatory properties, an event that may be relevant to the process of atherosclerosis.
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Affiliation(s)
- O Klezovitch
- Department of Medicine, University of Chicago, 5841 S. Maryland Ave., MC5041, Chicago, IL 60637, USA
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23
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Abstract
A high plasma concentration of lipoprotein Lp(a) is now considered to be a major and independent risk factor for cerebro- and cardiovascular atherothrombosis. The mechanism by which Lp(a) may favour this pathological state may be related to its particular structure, a plasminogen-like glycoprotein, apo(a), that is disulfide linked to the apo B100 of an atherogenic LDL-like particle. Apo(a) exists in several isoforms defined by a variable number of copies of plasminogen-like kringle 4 and single copies of kringle 5 and the catalytic region. At least one of the plasminogen-like kringle 4 copies present in apo(a) (kringle IV type 10) contains a lysine binding site (LBS) that is similar to that of plasminogen. This structure allows binding of these proteins to fibrin and cell membranes. Plasminogen thus bound is cleaved at Arg561-Val562 by plasminogen activators and transformed into plasmin. This mechanism ensures fibrinolysis and pericellular proteolysis. In apo(a) a Ser-Ile substitution at the Arg-Val plasminogen activation cleavage site prevents its transformation into a plasmin-like enzyme. Because of this structural/functional homology and enzymatic difference, Lp(a) may compete with plasminogen for binding to lysine residues and impair, thereby, fibrinolysis and pericellular proteolysis. High concentrations of Lp(a) in plasma may, therefore, represent a potential source of antifibrinolytic activity. Indeed, we have recently shown that during the course of the nephrotic syndrome the amount of plasminogen bound and plasmin formed at the surface of fibrin are directly related to in vivo variations in the circulating concentration of Lp(a) (Arterioscler. Thromb. Vasc. Biol., 2000, 20: 575-584; Thromb. Haemost., 1999, 82: 121-127). This antifibrinolytic effect is primarily defined by the size of the apo(a) polymorphs, which show heterogeneity in their fibrin-binding activity--only small size isoforms display high affinity binding to fibrin (Biochemistry, 1995, 34: 13353-13358). Thus, in heterozygous subjects the amount of Lp(a) or plasminogen bound to fibrin is a function of the affinity of each of the apo(a) isoforms and of their concentration relative to each other and to plasminogen. The real risk factor is, therefore, the Lp(a) subpopulation with high affinity for fibrin. According to this concept, some Lp(a) phenotypes may not be related to atherothrombosis and, therefore, high Lp(a) in some individuals might not represent a risk factor for cardiovascular disease. In agreement with these data, it has been recently reported that Lp(a) particles containing low molecular mass apo(a) emerged as one of the leading risk conditions in advanced stenotic atherosclerosis (Circulation, 1999, 100: 1154-1160). The predictive value of high Lp(a) as a risk factor, therefore, depends on the relative concentration of Lp(a) particles containing small apo(a) isoforms with the highest affinity for fibrin. Within this context, the development of agents able to selectively neutralise the antifibrinolytic activity of Lp(a), offers new perspectives in the prevention and treatment of the cardiovascular risk associated with high concentrations of thrombogenic Lp(a).
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Affiliation(s)
- E Anglés-Cano
- Institut National de la Santé et de la Recherche Médicale, U460, Faculté de Médecine Xavier-Bichat, France.
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24
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Zhang J, Ren S, Shen GX. Glycation amplifies lipoprotein(a)-induced alterations in the generation of fibrinolytic regulators from human vascular endothelial cells. Atherosclerosis 2000; 150:299-308. [PMID: 10856522 DOI: 10.1016/s0021-9150(99)00381-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased lipoprotein(a) [Lp(a)] in plasma is an independent risk factor for premature cardiovascular diseases. The levels of glycated Lp(a) are elevated in diabetic patients. The present study demonstrated that glycation enhanced Lp(a)-induced production of plasminogen activator inhibitor-1 (PAI-1), and further decreased the generation of tissue-type plasminogen activator (t-PA) from human umbilical vein endothelial cells (HUVEC) and human coronary artery EC. The levels of PAI-1 mRNA and its antigen in the media of HUVEC were significantly increased following treatments with 5 microgram/ml of glycated Lp(a) compared to equal amounts of native Lp(a). The secretion and de novo synthesis of t-PA, but not its mRNA level, in EC were reduced by glycated Lp(a) compared to native Lp(a). Treatment with aminoguanidine, an inhibitor for the formation of advanced glycation end products (AGEs), during glycation normalized the generation of PAI-1 and t-PA induced by glycated Lp(a). Butylated hydroxytoluene, a potent antioxidant, inhibited native and glycated Lp(a)-induced changes in PAI-1 and t-PA generation in EC. The results indicate that glycation amplifies Lp(a)-induced changes in the generation of PAI-1 and t-PA from venous and arterial EC. This may attenuate fibrinolytic activity in blood circulation and potentially contributes to the increased incidence of cardiovascular complications in diabetic patients with hyperlipoprotein(a). EC-mediated oxidative modification and the formation of AGEs may be implicated in glycated Lp(a)-induced alterations in the generation of fibrinolytic regulators from vascular EC.
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MESH Headings
- Biomarkers/blood
- Blotting, Northern
- Cardiovascular Diseases/blood
- Cardiovascular Diseases/etiology
- Cardiovascular Diseases/pathology
- Cells, Cultured
- Diabetes Complications
- Diabetes Mellitus/blood
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Enzyme Inhibitors/pharmacology
- Fibrinolysis/drug effects
- Fibrinolysis/physiology
- Glycation End Products, Advanced/pharmacology
- Glycosylation
- Guanidines/pharmacology
- Humans
- Lipoprotein(a)/drug effects
- Lipoprotein(a)/metabolism
- Lipoproteins, LDL/drug effects
- Lipoproteins, LDL/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Plasminogen Activator Inhibitor 1/biosynthesis
- Plasminogen Activator Inhibitor 1/genetics
- Plasminogen Activator Inhibitor 1/immunology
- Precipitin Tests
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Tissue Plasminogen Activator/biosynthesis
- Tissue Plasminogen Activator/drug effects
- Tissue Plasminogen Activator/genetics
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Affiliation(s)
- J Zhang
- Departments of Internal Medicine and Physiology, The University of Manitoba, BS440 730 William Ave, Manitoba, R3E 3J7, Winnipeg, Canada
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25
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Tan KC, Janus ED, Lam KS. Effects of fluvastatin on prothrombotic and fibrinolytic factors in type 2 diabetes mellitus. Am J Cardiol 1999; 84:934-7, A7. [PMID: 10532516 DOI: 10.1016/s0002-9149(99)00471-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effects of fluvastatin therapy on parameters of coagulation and fibrinolysis were evaluated in patients with diabetic dyslipidemia in a randomized, placebo-controlled study. Fluvastatin therapy was associated with a small reduction in factor VII coagulant activity, von Willebrand factor, and in plasminogen activator inhibitor 1 and tissue plasminogen activator antigens, but the effects of fluvastatin on hemostatic factors were much less marked than its effects on plasma lipids.
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Affiliation(s)
- K C Tan
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, China
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26
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Cockerill GW, Reed S. High-density lipoprotein: multipotent effects on cells of the vasculature. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 188:257-97. [PMID: 10208014 DOI: 10.1016/s0074-7696(08)61569-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The epidemiological evidence showing a strong inverse correlation between the level of plasma high-density lipoprotein (HDL) and the incidence of heart disease suggests that HDL has a protective effect against cardiovascular disease. The mechanism of this protective effect has been the raison d'etre for much research. The ability of HDL to mediate cholesterol efflux from peripheral tissues has been used to explain the cardioprotective effect of HDL. However, there is little direct evidence to suggest that in subjects with low plasma levels of HDL the rate of cholesterol efflux from peripheral tissues is significantly reduced. This observation suggested that HDL may be mediating its protective effect through other mechanisms. This review provides an account of the burgeoning evidence that HDL has many effects on cellular processes, in addition to the effects on cholesterol efflux, and will illustrate the multipotency of this lipoprotein.
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Affiliation(s)
- G W Cockerill
- Department of Cardiovascular Medicine, National Heart and Lung Institute, Imperial College School of Medicine, London, United Kingdom
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27
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Zhu Y, Liao HL, Wang N, Friedli O, Verna L, Stemerman MB. Low-density lipoprotein activates Jun N-terminal kinase (JNK) in human endothelial cells. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1436:557-64. [PMID: 9989285 DOI: 10.1016/s0005-2760(98)00167-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We have reported previously that native low-density lipoprotein (LDL) activates c-Jun and transcription factor AP-1 in human umbilical vein endothelial cells (HUVEC). The aim of this study was to elucidate the upstream signaling mechanisms mediating LDL activation of c-Jun/AP-1. Using a c-Jun NH2-terminal kinase (JNK) activity assay, we have detected an increase in JNK activity in LDL-exposed HUVEC, which started at 15 min and reached maximum activity after 1-2 h. This JNK activity, increased by LDL, occurred in a dose-dependent fashion starting at a concentration of 80 mg/dl of LDL and reaching maximum activation at a concentration of 160-240 mg/dl. Following cotransfection, the increase of AP-1 driven luciferase activity by LDL was attenuated 54% by a kinase-deficient JNK1. Furthermore, a specific trans-reporting system was utilized to confirm c-Jun activation by upstream signal mechanisms. The results show c-Jun activity increased by 3-fold after LDL exposure when compared with respective controls. In contrast, LDL exposure did not affect the activation of extracellular signal regulated kinase 1 and 2 (ERK1/2), even though phorbol 12-myristate 13-acetate treatment remarkably increased the activity of these kinases. Thus, this study demonstrates, for the first time, that JNK mediates LDL-induced endothelial cell activation.
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Affiliation(s)
- Y Zhu
- Division of Biomedical Sciences, University of California, Riverside 92521, USA.
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28
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Abstract
Since its identification by Kåre Berg in 1963, lipoprotein(a) [Lp(a)] has become a focus of research interest owing to the results of case-control and prospective studies linking elevated plasma levels of this lipoprotein with the development of coronary artery disease. Lp(a) contains a low-density lipoprotein (LDL)-like moiety, in which the apolipoprotein B-100 component is covalently linked to the unique glycoprotein apolipoprotein(a) [apo(a)]. Apo(a) is composed of repeated loop-shaped units called kringles, the sequences of which are highly similar to a kringle motif present in the fibrinolytic proenzyme plasminogen. Variability in the number of repeated kringle units in the apo(a) molecule gives rise to different-sized Lp(a) isoforms in the population. Based on the similarity of Lp(a) to both LDL and plasminogen, it has been hypothesized that the function of this unique lipoprotein may represent a link between the fields of atherosclerosis and thrombosis. However, determination of the function of Lp(a) in vivo remains elusive. Although Lp(a) has been shown to accumulate in atherosclerotic lesions, its contribution to the development of atheromas is unclear. This uncertainty is related in part to the structural complexity of the apo(a) component of Lp(a) (particularly apo(a) isoform size heterogeneity), which also poses a challenge for standardization of the measurement of Lp(a) in plasma. The fact that plasma Lp(a) levels are largely genetically determined and vary widely among different ethnic groups adds scientific interest to the ongoing study of this enigmatic particle. Most recently, the identification of proteolytic fragments of apo(a) in both plasma and urine has fueled speculation about the origin of these fragments and their possible function in the atherosclerotic process.
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Affiliation(s)
- S M Marcovina
- Department of Medicine, University of Washington, Seattle 98103-9103, USA
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29
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Abstract
Atherosclerotic plaque rupture and erosions precipitate thrombus formation and may lead to an acute ischemic syndrome. Lipids and lipoproteins modulate the expression and/or function of thrombotic, fibrinolytic and rheologic factors, and thereby influence hemostasis and potential tissue damage resulting from vascular injury. Triglyceride-enriched lipoproteins are accompanied by elevations in factor VII clotting activity, plasminogen activator inhibitor (PAI-1) and viscosity of blood and plasma. Low density lipoprotein (LDL) promotes platelet activation and tissue factor expression and LDL levels correlate with levels of vitamin K dependent coagulation factors and fibrinogen. Conversely, LDL inhibits tissue factor pathway inhibitor (TFPI) which limits activation of the extrinsic coagulation pathway. High density lipoprotein (HDL) has anti-atherothrombotic properties that result from inhibition of platelet and erythrocyte aggregation, reduced blood viscosity and suppression of tissue factor activity and PAI-1 activity and antigen levels. The effects of lipids and lipoproteins on hemostasis and rheology may have important implications for the clinical sequelae following plaque disruption and erosion.
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Affiliation(s)
- R S Rosenson
- Department of Medicine, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612, USA.
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30
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Gräfe M, Auch-Schwelk W, Hertel H, Terbeek D, Steinheider G, Loebe M, Fleck E. Human cardiac microvascular and macrovascular endothelial cells respond differently to oxidatively modified LDL. Atherosclerosis 1998; 137:87-95. [PMID: 9568740 DOI: 10.1016/s0021-9150(97)00258-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oxidation of low density lipoproteins (LDL) is considered a key event in the pathogenesis of atherosclerotic lesions. Disturbed generation of coagulatory and anticoagulatory factors by endothelial cells contributes to thrombosis and the progression of atherosclerosis in coronary arteries. In this study, the effects of native LDL (n-LDL) and oxidized LDL (ox-LDL) on human coronary endothelial cells were measured. The reaction of coronary endothelial cells to LDL were compared with those of cardiac microvascular endothelial cells grown under comparable conditions. LDL was isolated by ultracentrifugation and copper oxidized. The degree of oxidation was expressed as malondialdehyd (MDA) equivalents and was 0.78+/-0.14 nM MDA/mg LDL for native LDL and 13.63+/-1.18 nmol MDA/mg LDL for ox-LDL. Basal secretion of t-PA and PAI-1 activity were higher in macrovascular endothelial cells. Incubation of n-LDL in concentrations ranging from 3 to 100 microM/ml LDL-protein did not change t-PA-secretion, PAI-1 activity or procoagulant activity in both cell types. Ox-LDL (3 to 100 microM/ml LDL protein) decreased t-PA secretion in a concentration dependent manner from 30.9+/-1.7 to 13.7+/-30 ng/ml per 24 h per 10(6) cells (P < 0.01), increased PAI-1 antigen from 2772+/-587 to 4441+/-766 ng/ml per 24 h per 10(6) cells (P < 0.05) as well as PAI-1 activity from 34+/-6 to 55+/-9 AU/ml per 24 h per 10(6) cells (P < 0.05) in macrovascular endothelial cells but had only minor effects on microvascular endothelial cells. Procoagulant activity measured as coagulation time, similarly increased only in macrovascular endothelial cells from 197+/-6 to 76+/-6 s/24 h per 10(6) cells (P < 0.05). The effect on PAI-1 secretion showed a dependency to the degree of oxidation and could be completely blocked by the antioxidant probucol. The angiotensin converting enzyme (ACE), which represents an endothelial enzyme not related to coagulation, remained unchanged during incubation with ox-LDL. Basal ACE activity was higher in microvascular endothelial cells. The higher susceptibility of macrovascular endothelial cells to ox-LDL may partially determine the localization of thrombus formation and the development of atherosclerotic plaques in hyperlipidemic patients.
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Affiliation(s)
- M Gräfe
- Department of Medicine/Cardiology, German Heart Institute and Virchow Klinikum, Humboldt University, Berlin.
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31
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Berge KE, Djurovic S, Muller HJ, Alestrøm P, Berg K. Studies on effects of Lp(a) lipoprotein on gene expression in endothelial cells in vitro. Clin Genet 1997; 52:314-25. [PMID: 9520122 DOI: 10.1111/j.1399-0004.1997.tb04349.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The reason(s) for the atherogenic properties of Lp(a) lipoprotein is still unclear, and several mechanisms have been studied. Alterations in gene expression in endothelial cells (ECs) could be important with respect to risk for coronary heart disease (CHD). We have tested the effects of Lp(a) lipoprotein or the apolipoprotein of Lp(a) lipoprotein (apo(a)) on cultured human umbilical vein endothelial cells (HUVECs) with respect to: (1) the level of endothelin-1 (ET-1) mRNA; (2) release of ET-1 into the culture medium; (3) plasminogen activator inhibitor-1 (PAI-1) secretion into the culture medium and; (4) total gene expression in HUVECs, examined by a polymerase chain reaction (PCR)-based technique, differential display-reverse transcription-PCR (DD-RT-PCR). Lp(a) lipoprotein reduced the level of ET-1 mRNA as well as the release of ET-1. The reduction of ET-1 in the medium was even more pronounced when HUVECs were incubated with apo(a), but we found no effect of apo(a) on ET-1 mRNA level. Neither Lp(a) lipoprotein nor apo(a) had a significant influence on PAI-1 secretion. DD-RT-PCR revealed 11 fragments that could represent differences between cells exposed or not exposed to Lp(a) lipoprotein. Following subcloning and sequencing, 18 sequences that differed between exposed and unexposed cultures were obtained. Four of the subcloned fragments have up to now been used as a probe for northern blot analyses, and one fragment was confirmed to be regulated by Lp(a) lipoprotein. In conclusion, Lp(a) lipoprotein is shown to control ET-1 mRNA levels and the function of at least one more gene, the nature of which is unknown.
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Affiliation(s)
- K E Berge
- Institute of Medical Genetics, University of Oslo, Department of Medical Genetics, Ullevål University Hospital, Norway
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32
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Anglés-Cano E. Structural basis for the pathophysiology of lipoprotein(a) in the athero-thrombotic process. Braz J Med Biol Res 1997; 30:1271-80. [PMID: 9532233 DOI: 10.1590/s0100-879x1997001100002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Lipoprotein Lp(a) is a major and independent genetic risk factor for atherosclerosis and cardiovascular disease. The essential difference between Lp(a) and low density lipoproteins (LDL) is apolipoprotein apo(a), a glycoprotein structurally similar to plasminogen, the precursor of plasmin, the fibrinolytic enzyme. This structural homology endows Lp(a) with the capacity to bind to fibrin and to membrane proteins of endothelial cells and monocytes, and thereby to inhibit plasminogen binding and plasmin generation. The inhibition of plasmin generation and the accumulation of Lp(a) on the surface of fibrin and cell membranes favor fibrin and cholesterol deposition at sites of vascular injury. Moreover, insufficient activation of TGF-beta due to low plasmin activity may result in migration and proliferation of smooth muscle cells into the vascular intima. These mechanisms may constitute the basis of the athero-thrombogenic mode of action of Lp(a). It is currently accepted that this effect of Lp(a) is linked to its concentration in plasma. An inverse relationship between Lp(a) concentration and apo(a) isoform size, which is under genetic control, has been documented. Recently, it has been shown that inhibition of plasminogen binding to fibrin by apo(a) is also inversely associated with isoform size. Specific point mutations may also affect the lysine-binding function of apo(a). These results support the existence of functional heterogeneity in apolipoprotein(a) isoforms and suggest that the predictive value of Lp(a) as a risk factor for vascular occlusive disease would depend on the relative concentration of the isoform with the highest affinity for fibrin.
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Affiliation(s)
- E Anglés-Cano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U. 143, Centre Hospitalier Universitaire de Bicêtre, Université de Paris-Sud, Paris, France.
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33
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Falkenberg M, Karlsson J, Ortenwall P. Peripheral arterial thrombosis in two young men using anabolic steroids. Eur J Vasc Endovasc Surg 1997; 13:223-6. [PMID: 9091161 DOI: 10.1016/s1078-5884(97)80025-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- M Falkenberg
- Department of Surgery, Ostra Hospital, University of Göteborg, Sweden
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34
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Ren S, Man RY, Angel A, Shen GX. Oxidative modification enhances lipoprotein(a)-induced overproduction of plasminogen activator inhibitor-1 in cultured vascular endothelial cells. Atherosclerosis 1997; 128:1-10. [PMID: 9051192 DOI: 10.1016/s0021-9150(96)05971-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Elevated levels of plasma lipoprotein (a) [Lp(a)] have been considered as a strong risk factor for premature cardiovascular diseases. Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of plasminogen activators (PA). Increases in PAI-1 levels with or without a reduction in PA levels have been frequently found in coronary artery disease patients. The present paper examined the effects of oxidized Lp(a) on the production of PAI-1 in cultured human umbilical vein endothelial cells (HUVEC). Lp(a) and Lp(a)-free, low density lipoprotein (LDL) were prepared using lysine-Sepharose 4B affinity chromatography. Incubations with 10(-8) M levels of native Lp(a) moderately increased the levels of biologically active PAI-1 in post-culture medium of HUVEC compared to that with equimolar concentrations of native Lp(a)-free LDL. The release of PAI-1 induced by Lp(a) was enhanced by oxidative modification with copper ion. The stimulation of oxidized Lp(a) on PAI-1 production reached plateau in EC treated with 10-20 nM oxidized Lp(a) modified by microM CuSO4. Treatment with 0.2 micrograms/ml of actinomycin D significantly reduced native and oxidized Lp(a)-induced PAI-1 overproduction in EC. Increases in the steady state levels of PAI-1 mRNA were detected in native or oxidized Lp(a)-treated EC. The effect of Lp(a)-free oxidized LDL on PAI-1 production was significantly weaker than the equimolar amount of oxidized Lp(a) but stronger than that of native LDL. Treatments with oxidized Lp(a) increased cell-associated PAI-1 to a similar extent as that in native Lp(a)-treated EC. The results of the present paper demonstrate that oxidative modification enhances Lp(a)-induced PAI-1 production in vascular endothelial cells at RNA transcription level, which suggests that oxidization potentially amplifies the anti-fibrinolytic and thrombotic effect of Lp(a).
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Affiliation(s)
- S Ren
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
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Koschinsky ML, Marcovina SM. Lipoprotein(a): structural implications for pathophysiology. INTERNATIONAL JOURNAL OF CLINICAL & LABORATORY RESEARCH 1997; 27:14-23. [PMID: 9144023 DOI: 10.1007/bf02827238] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The assembly between a low-density lipoprotein particle and apolipoprotein(a), a highly carbohydrate-rich protein, gives origin to a peculiar class of lipoproteins, only found in the hedgehog, primates, and humans, termed lipoprotein(a). Apolipoprotein(a), which shares a high degree of sequence homology with the fibrinolytic proenzyme plasminogen, is linked to the apolipoprotein B-100 component of low-density lipoprotein via a disulfide bond and confers distinct biochemical and metabolic properties to lipoprotein(a). Because of its peculiar structural features and the observed correlation between high lipoprotein(a) levels and the development of a variety of atherosclerotic disorders, this lipoprotein has become the focus of an intense research effort. Although accumulation of lipoprotein(a) in the vessel wall at sites of vascular injury has been clearly evidenced, the mechanism(s) by which lipoprotein(a) exerts its pathogenic effect in this milieu remain largely unknown. It has been hypothesized that the pathological effect of lipoprotein(a) is related either to its similarity to low-density lipoprotein (i.e., a pro-atherogenic effect) or to the apolipoprotein(a) similarity to plasminogen (i.e., a pro-thrombotic/anti-fibrinolytic effect). However, it is probable that both components contribute to the pathogenicity of lipoprotein(a). The fact that lipoprotein(a) levels are largely genetically determined, varying widely among individuals and racial groups, adds additional elements to the scientific interest that surrounds this lipoprotein. Both clinical and biochemical studies of lipoprotein(a) have been complicated by the high degree of structural heterogeneity of apolipoprotein(a), which is considered the most polymorphic protein in human plasma. Our aim in this paper is to provide an overview of the most salient structural features of lipoprotein(a) and their possible pathophysiological implications.
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Affiliation(s)
- M L Koschinsky
- Department of Biochemistry, Queen's University, Kingston, Ontario, Canada
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Lopes-Virella MF, Virella G. Modified lipoproteins, cytokines and macrovascular disease in non-insulin-dependent diabetes mellitus. Ann Med 1996; 28:347-54. [PMID: 8862690 DOI: 10.3109/07853899608999092] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The processes of glycation and oxidation play a significant role in the acceleration of atherosclerosis in diabetes mellitus. Glycation is thought not only to increase the susceptibility of low-density lipoprotein (LDL) to oxidation but also to enhance the propensity of vessel wall structural proteins to bind extravasated plasma proteins, including LDL, and thus to contribute to a more marked oxidative modification of LDL. Glycated and oxidized lipoproteins induce cholesteryl ester accumulation in human macrophages and may promote platelet and endothelial cell dysfunction. Furthermore, these modified lipoproteins have the ability to trigger an autoimmune response that leads to the formation of autoantibodies and subsequently to the formation of immune complexes containing LDL. Both the modified lipoproteins and the immune complexes formed with autoantibodies reactive with modified lipoproteins may be responsible for several alternative and not mutually exclusive pathways leading to foam cell formation, macrophage activation and endothelial cell damage and may thus be of potential significance in initiating and/or contributing to the acceleration of the development of atherosclerosis. In this review we discuss how modified LDL affects lipoprotein metabolism, how immune complexes containing LDL induce the transformation of macrophages into foam cells and promote macrophage activation leading to the release of cytokines and thus initiating a sequence of events leading to endothelial cell damage and to the recruitment and activation of leucocytes. We also summarize our work showing that macrophage activation by LDL containing immune complexes leads to a paradoxical increase in LDL-receptor expression thus further impairing cholesterol homeostasis and enhancing the development of atheromatous lesions.
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Affiliation(s)
- M F Lopes-Virella
- Ralph H. Johnson Department of Veterans Affairs Medical Center, Charieston, SC 29403, USA
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Testa R, Bonfigli AR, Piantanelli L, Manfrini S, Testa I, Gregorio F. Relationship between plasminogen activator inhibitor type-1 plasma levels and the lipoprotein(a) concentrations in non-insulin-dependent diabetes mellitus. Diabetes Res Clin Pract 1996; 33:111-8. [PMID: 8879966 DOI: 10.1016/0168-8227(96)01286-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The first part of the paper deals with the relationship between two inhibiting factors of the complex enzyme cascade regulating fibrinolysis, namely plasminogen activator inhibitor type-1 (PAI-1) and lipoprotein(a) (Lp(a)). Blood concentrations of Lp(a), PAI-1 antigen (PAI-1 AG) and activity (PAI-1 AT), and the main parameters of lipo- and glyco-metabolic balance were studied in 80 type II diabetic patients. Roughly hyperbolic patterns have been found between PAI-1 and Lp(a). Negative statistically significant linear correlation can be elicited when Log PAI-1 AG and Log PAI-1 AT values are plotted versus Lp(a) values, the first one being particularly tight. These findings suggest a nearly on/off control of the two parameters, limiting the risk of hypofibrinolysis. The second part of the paper was aimed at verifying this hypothesis. A group of 30 diabetic patients were treated for 3 months with metformin, an antidiabetic biguanide compound which has been reported to reduce PAI-1 levels both in diabetic and in non-diabetic patients. Metformin significantly reduced PAI-1 AG and PAI-1 AT but did not influence plasma Lp(a) levels. A clear linear correlation between the basal Lp(a) values and the changes in PAI-1 AG levels was found. An even tighter correlation was elicited between the decrease in PAI-1, and PAI-1 pretreatment values.
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Affiliation(s)
- R Testa
- Gerontological Research Dept., Italian National Research Centres on Aging (INRCA), Ancona, Italy
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Li XN, Koons JC, Benza RL, Parks JM, Varma VK, Bradley WA, Gianturco SH, Taylor KB, Grammer JR, Tabengwa EM, Booyse FM. Hypertriglyceridemic VLDL decreases plasminogen binding to endothelial cells and surface-localized fibrinolysis. Biochemistry 1996; 35:6080-8. [PMID: 8634250 DOI: 10.1021/bi952032i] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effect of normo (NTG)- and hypertriglyceridemic (HTG)-VLDL on cultured human umbilical vein endothelial cell (HUVEC) surface-localized fibrinolysis was examined following pre-incubation with NTG-, HTG-VLDL, LDL (1-20 micrograms/mL) or buffer (control). Ligand binding assays, using 125I-labeled tcu-PA, t-PA, or Glu-plasminogen (Glu-Pmg) were carried out in the absence/presence of lipoproteins. Scatchard analyses showed that HTG-VLDL decreased the Bmax for 125I-labeled Glu-Pmg ligand binding approximately 35% [(2.11 +/- 0.39)-(1.40 +/- 0.32) x 10(6) sites/cell, p < 0.005] and increased the Kd, app approximately 5-fold (0.32 +/- 0.03 to 1.74 +/- 0.08 microM, p < 0.01), while NTG-VLDL, LDL, and buffer had no effect. 125I-labeled PA ligand binding was unaffected by these lipoproteins. Receptor-bound PA activation of cell-bound 125I-labeled Glu-Pmg was measured by quantitation of either the M(r) 20 kDa light- or M(r) 60 kDa heavy-chain of 125I-labeled plasmin, following SDS-PAGE. Kinetic analysis of these data (HTG-VLDL vs controls) indicated that HTG-VLDL decreased the V(max) of tcu-PA- and t-PA-mediated activation of plasminogen approximately 2.7-fold (0.317 +/- 0.023 vs 0.869 +/- 0.068 nM s-1, p < 0.01) and approximately 2.9-fold (0.391 +/- 0.098 vs 1.152 +/- 0.265 nM s-1, p < 0.01), respectively. Increasing concentrations of the HTG-VLDL increased 1/V(max), yielding a series of parallel plots, typical for uncompetitive inhibition with a Ki for inhibition of approximately 10 micrograms/mL. The combined ligand binding and kinetic data best fit an uncompetitive inhibition model in which the binding of the large HTG-VLDL particle to the EC surface may directly affect Glu-Pmg binding and activation, thus contributing to early fibrin deposition and the increased thrombotic risk associated with HTG.
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Affiliation(s)
- X N Li
- Department of Medicine, University of Alabama at Birmingham 35294-2170, USA
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Abstract
The link between impaired fibrinolytic function and CHD has been reinforced considerably in the past couple of years. This has been achieved by a combination of epidemiological, clinical, cell biological and molecular biological studies. The molecular mechanisms for the identified associations between more established risk factors for atherosclerotic disease and impaired fibrinolytic function now need to be disentangled to promote the design of specific drugs that may pave the way for intervention. The possibility that some of the observed relations are epiphenomena should also not be disregarded. The concept of genotype-specific differences in the susceptibility of the individual to common metabolic disturbances needs to be examined in greater detail. Basic research on the role of fibrinolysis in atherosclerosis and its thrombotic complications should be given high priority, because the modulation of fibrinolytic function is likely to become an important approach to prevention.
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Affiliation(s)
- A Hamsten
- King Gustaf V Research Institute, Department of Medicine, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden
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Abstract
Case-control and cohort studies support the hypothesis that postmenopausal oestrogen-replacement therapy reduces the risk of atherosclerotic disease manifestations. The evidence for a cardioprotective effect of such a therapy is, however, incomplete because randomized prospective studies are missing. Because it may be almost impossible to conduct placebo-controlled trials in the future, other study designs will be needed to minimize selection bias. Further work is required to define the optimal dose and administration schedule of oestrogen and to determine whether addition of progestogens alters the beneficial effect of oestrogen on the cardiovascular system. Such studies may also provide mechanistic insight into the interaction between lipoprotein metabolism and haemostasis and its relation to the atherosclerotic disease process.
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Affiliation(s)
- F Krempler
- Department of Medicine, Krankenhaus Hallein, Austria
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