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Kietsiriroje N, Scott GE, Ajjan RA, Brôz J, Schroeder V, Campbell MD. Plasma levels of mannan-binding lectin-associated serine proteases are increased in type 1 diabetes patients with insulin resistance. Clin Exp Immunol 2024; 215:58-64. [PMID: 37832142 PMCID: PMC10776244 DOI: 10.1093/cei/uxad113] [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: 05/06/2023] [Revised: 07/07/2023] [Accepted: 10/12/2023] [Indexed: 10/15/2023] Open
Abstract
Activation of the lectin pathway of the complement system, as demonstrated by elevated levels of mannan-binding lectin proteins (MBL), contributes to vascular pathology in type 1 diabetes (T1D). Vascular complications are greatest in T1D individuals with concomitant insulin resistance (IR), however, whether IR amplifies activiation of the lectin pathway in T1D is unknown. We pooled pretreatment data from two RCTs and performed a cross-sectional analysis on 46 T1D individuals. We employed estimated glucose disposal rate (eGDR), a validated IR surrogate with cut-points of: <5.1, 5.1-8.7, and > 8.7 mg/kg/min to determine IR status, with lower eGDR values conferring higher degrees of IR. Plasma levels of MBL-associated proteases (MASP-1, MASP-2, and MASP-3) and their regulatory protein MAp44 were compared among eGDR classifications. In a subset of 14 individuals, we assessed change in MASPs and MAp44 following improvement in IR. We found that MASP-1, MASP-2, MASP-3, and MAp44 levels increased in a stepwise fashion across eGDR thresholds with elevated MASPs and MAp44 levels conferring greater degrees of IR. In a subset of 14 patients, improvement in IR was associated with significant reductions in MASPs, but not MAp44, levels. In conclusion, IR in T1D amplifies levels of MASP-1/2/3 and their regulator MAp44, and improvement of IR normalizes MASP-1/2/3 levels. Given that elevated levels of these proteins contribute to vascular pathology, amplification of the lectin pathway of the complement system may offer mechanistic insight into the relationship between IR and vascular complications in T1D.
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Affiliation(s)
- Noppadol Kietsiriroje
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
- Endocrinology and Metabolism Unit, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand
| | - Georgia E Scott
- School of Nursing and Health Sciences, University of Sunderland, Sunderland, UK
| | - Ramzi A Ajjan
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Jan Brôz
- Department of Internal Medicine, Charles University, Prague, Czech Republic
| | - Verena Schroeder
- Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Matthew D Campbell
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
- School of Nursing and Health Sciences, University of Sunderland, Sunderland, UK
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2
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Jenny L, Melmer A, Laimer M, Hardy ET, Lam WA, Schroeder V. Diabetes affects endothelial cell function and alters fibrin clot formation in a microvascular flow model: A pilot study. Diab Vasc Dis Res 2020; 17:1479164120903044. [PMID: 32037878 PMCID: PMC7510361 DOI: 10.1177/1479164120903044] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Diabetes is a proinflammatory and prothrombotic condition that increases the risk of vascular complications. The aim of this study was to develop a diabetic microvascular flow model that allows to study the complex interactions between endothelial cells, blood cells and plasma proteins and their effects on clot formation. Primary human cardiac microvascular endothelial cells from donors without diabetes or donors with diabetes (type 1 or type 2) were grown in a microfluidic chip, perfused with non-diabetic or diabetic whole blood, and clot formation was assessed by measuring fibrin deposition in real time by confocal microscopy. Clot formation in non-diabetic whole blood was significantly increased in the presence of endothelial cells from donors with type 2 diabetes compared with cells from donors without diabetes. There was no significant difference in clot formation between non-diabetic and diabetic whole blood. We present for the first time a diabetic microvascular flow model as a new tool to study clot formation as a result of the complex interactions between endothelial cells, blood cells and plasma proteins in a diabetes setting. We show that endothelial cells affect clot formation in whole blood, attributing an important role to the endothelium in the development of atherothrombotic complications.
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Affiliation(s)
- Lorenz Jenny
- Experimental Haemostasis Group, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Andreas Melmer
- University Clinic for Diabetology, Endocrinology, Nutritional Medicine and Metabolism, University Hospital of Bern, Inselspital, Bern, Switzerland
| | - Markus Laimer
- University Clinic for Diabetology, Endocrinology, Nutritional Medicine and Metabolism, University Hospital of Bern, Inselspital, Bern, Switzerland
| | - Elaissa T Hardy
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Wilbur A Lam
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Verena Schroeder
- Experimental Haemostasis Group, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
- Verena Schroeder, Experimental Haemostasis Group, Department for BioMedical Research, University of Bern, Murtenstrasse 40, 3008 Bern, Switzerland.
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3
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Role of complement in diabetes. Mol Immunol 2019; 114:270-277. [PMID: 31400630 DOI: 10.1016/j.molimm.2019.07.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023]
Abstract
Accumulating evidence suggests a role for the complement system in the pathogenesis of diabetes and the vascular complications that characterise this condition. Complement proteins contribute to the development of type 1 diabetes (T1D) by enhancing the underlying organ-specific autoimmune processes. Complement upregulation and activation is also an important feature of insulin resistance and the development of type 2 diabetes (T2D). Moreover, animal and human studies indicate that complement proteins are involved in the pathogenic mechanisms leading to diabetic microvascular and macrovascular complications. The adverse vascular effects of complement appear to be related to enhancement of the inflammatory process and the predisposition to a thrombotic environment, eventually leading to vascular occlusion. Complement proteins have been considered as therapeutic targets to prevent or treat vascular disease but studies have been mainly conducted in animal models, while human work has been both limited and inconclusive so far. Further studies are needed to understand the potential role of complement proteins as therapeutic targets for reversal of the pathological processes leading to T1D and T2D and for the prevention/treatment of diabetic vascular complications.
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Ghassemi F, Shields CL, Mohebbi M, Nili Ahmadabadi M, Morsali F, Sabour S. Serum hypercoagulability states in Coats' disease. Clin Ophthalmol 2017; 11:305-310. [PMID: 28223774 PMCID: PMC5308596 DOI: 10.2147/opth.s121375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the serum hypercoagulability state and common viral and protozoan infections in Coats' disease versus a normal control group. MATERIALS AND METHODS In this comparative case series, 22 consecutive patients with Coats' disease and 19 non-Coats' patients undergoing lensectomy for congenital, traumatic, or senile cataract between January 2011 and June 2014 were included. Laboratory data for hypercoagulability states and common viral and protozoan infections were investigated. RESULTS =0.02). CONCLUSION Serum beta globulin levels appear to be elevated in patients with Coats' disease.
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Affiliation(s)
- Fariba Ghassemi
- Ocular Oncology and Retina and Vitreous Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Carol L Shields
- Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA, USA
| | - Masoumeh Mohebbi
- Ocular Oncology and Retina and Vitreous Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Nili Ahmadabadi
- Ocular Oncology and Retina and Vitreous Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Morsali
- Ocular Oncology and Retina and Vitreous Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Siamak Sabour
- Safety Promotion and Injury Prevention Research Centre; Department of Clinical Epidemiology, School of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Jenny L, Ajjan R, King R, Thiel S, Schroeder V. Plasma levels of mannan-binding lectin-associated serine proteases MASP-1 and MASP-2 are elevated in type 1 diabetes and correlate with glycaemic control. Clin Exp Immunol 2015; 180:227-32. [PMID: 25533914 DOI: 10.1111/cei.12574] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2014] [Indexed: 12/17/2022] Open
Abstract
There is increasing evidence that the complement system plays an important role in diabetes and the development of diabetic vascular complications. In particular, mannan-binding lectin (MBL) levels are elevated in diabetes patients, and diabetes patients with diabetic nephropathy have higher MBL levels than diabetes patients with normal renal function. The MBL-associated serine proteases (MASPs) MASP-1, MASP-2 and MASP-3 and MBL-associated protein MAp44 have not yet been studied in diabetes patients. We therefore measured plasma levels of MASP-1, MASP-2, MASP-3 and MAp44 in 30 children with type 1 diabetes mellitus (T1DM) and 17 matched control subjects, and in 45 adults with T1DM and 31 matched control subjects. MASP-1 and MASP-2 levels were significantly higher in children and adults with T1DM than in their respective control groups, whereas MASP-3 and MAp44 levels did not differ between patients and controls. MASP-1 and MASP-2 levels correlated with HbA1c, and MASP levels decreased when glycaemic control improved. Because MASP-1 and MASP-2 have been shown to interact directly with blood coagulation, elevated levels of these proteins may play a role in the enhanced thrombotic environment and consequent vascular complications in diabetes.
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Affiliation(s)
- L Jenny
- University Clinic of Haematology, Haemostasis Research Laboratory, University Hospital of Bern, Bern, Switzerland; Department of Clinical Research, University of Bern, Bern, Switzerland
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6
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Hess K. The vulnerable blood. Coagulation and clot structure in diabetes mellitus. Hamostaseologie 2014; 35:25-33. [PMID: 25418205 DOI: 10.5482/hamo-14-09-0039] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 11/11/2014] [Indexed: 01/04/2023] Open
Abstract
Patients with diabetes are at increased risk of cardiovascular morbidity and mortality. While arteriosclerotic lesions have long been recognized as the underlying cause more recent studies suggest that alterations of the blood are also critically involved. Following plaque rupture, adherence of platelets is followed by the formation of a cross-linked fibrin clot. Patients with diabetes exhibit a prothrombotic milieu consisting of hyper reactive platelets, a tight and rigid clot structure which is due to up-regulation of coagulation factors and prolongation of clot lysis. Metabolic alterations as well as inflammatory processes, which are up-regulated in diabetes, are thought to be the main underlying causes. More recently, the complement cascade has emerged as a potential new player in this context with several complement components directly influencing both platelet function and coagulation. This review provides an overview concerning the changes that lead to alterations of platelet function and clot structure in diabetes.
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Affiliation(s)
- K Hess
- Dr. Katharina Hess, Department of Internal Medicine I, University Hospital Pauwelsstr. 30, 52074 Aachen, Germany, Tel. +49/(0)241/803 71 28, Fax +49/(0)241/808 25 45, E-mail:
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Hess K, Alzahrani SH, Price JF, Strachan MW, Oxley N, King R, Gamlen T, Schroeder V, Baxter PD, Ajjan RA. Hypofibrinolysis in type 2 diabetes: the role of the inflammatory pathway and complement C3. Diabetologia 2014; 57:1737-41. [PMID: 24838681 DOI: 10.1007/s00125-014-3267-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 04/29/2014] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS Plasminogen activator inhibitor-1 (PAI-1) has been regarded as the main antifibrinolytic protein in diabetes, but recent work indicates that complement C3 (C3), an inflammatory protein, directly compromises fibrinolysis in type 1 diabetes. The aim of the current project was to investigate associations between C3 and fibrinolysis in a large cohort of individuals with type 2 diabetes. METHODS Plasma levels of C3, C-reactive protein (CRP), PAI-1 and fibrinogen were analysed by ELISA in 837 patients enrolled in the Edinburgh Type 2 Diabetes Study. Fibrin clot lysis was analysed using a validated turbidimetric assay. RESULTS Clot lysis time correlated with C3 and PAI-1 plasma levels (r = 0.24, p < 0.001 and r = 0.22, p < 0.001, respectively). In a multivariable regression model involving age, sex, BMI, C3, PAI-1, CRP and fibrinogen, and using log-transformed data as appropriate, C3 was associated with clot lysis time (regression coefficient 0.227 [95% CI 0.161, 0.292], p < 0.001), as was PAI-1 (regression coefficient 0.033 [95% CI 0.020, 0.064], p < 0.05) but not fibrinogen (regression coefficient 0.003 [95% CI -0.046, 0.051], p = 0.92) or CRP (regression coefficient 0.024 [95% CI -0.008, 0.056], p = 0.14). No correlation was demonstrated between plasma levels of C3 and PAI-1 (r = -0.03, p = 0.44), consistent with previous observations that the two proteins affect different pathways in the fibrinolytic system. CONCLUSIONS/INTERPRETATION Similarly to PAI-1, C3 plasma levels are independently associated with fibrin clot lysis in individuals with type 2 diabetes. Therefore, future studies should analyse C3 plasma levels as a surrogate marker of fibrinolysis potential in this population.
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Affiliation(s)
- Katharina Hess
- Department of Cardiology, University Hospital RWTH Aachen, Aachen, Germany
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8
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The complement system in human cardiometabolic disease. Mol Immunol 2014; 61:135-48. [PMID: 25017306 DOI: 10.1016/j.molimm.2014.06.031] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/18/2014] [Accepted: 06/23/2014] [Indexed: 02/07/2023]
Abstract
The complement system has been implicated in obesity, fatty liver, diabetes and cardiovascular disease (CVD). Complement factors are produced in adipose tissue and appear to be involved in adipose tissue metabolism and local inflammation. Thereby complement links adipose tissue inflammation to systemic metabolic derangements, such as low-grade inflammation, insulin resistance and dyslipidaemia. Furthermore, complement has been implicated in pathophysiological mechanisms of diet- and alcohol induced liver damage, hyperglycaemia, endothelial dysfunction, atherosclerosis and fibrinolysis. In this review, we summarize current evidence on the role of the complement system in several processes of human cardiometabolic disease. C3 is the central component in complement activation, and has most widely been studied in humans. C3 concentrations are associated with insulin resistance, liver dysfunction, risk of the metabolic syndrome, type 2 diabetes and CVD. C3 can be activated by the classical, the lectin and the alternative pathway of complement activation; and downstream activation of C3 activates the terminal pathway. Complement may also be activated via extrinsic proteases of the coagulation, fibrinolysis and the kinin systems. Studies on the different complement activation pathways in human cardiometabolic disease are limited, but available evidence suggests that they may have distinct roles in processes underlying cardiometabolic disease. The lectin pathway appeared beneficial in some studies on type 2 diabetes and CVD, while factors of the classical and the alternative pathway were related to unfavourable cardiometabolic traits. The terminal complement pathway was also implicated in insulin resistance and liver disease, and appears to have a prominent role in acute and advanced CVD. The available human data suggest a complex and potentially causal role for the complement system in human cardiometabolic disease. Further, preferably longitudinal studies are needed to disentangle which aspects of the complement system and complement activation affect the different processes in human cardiometabolic disease.
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Dobó J, Schroeder V, Jenny L, Cervenak L, Závodszky P, Gál P. Multiple roles of complement MASP-1 at the interface of innate immune response and coagulation. Mol Immunol 2014; 61:69-78. [PMID: 24935208 DOI: 10.1016/j.molimm.2014.05.013] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 05/26/2014] [Accepted: 05/27/2014] [Indexed: 11/24/2022]
Abstract
MASP-1 is a versatile serine protease that cleaves a number of substrates in human blood. In recent years it became evident that besides playing a crucial role in complement activation MASP-1 also triggers other cascade systems and even cells to mount a more powerful innate immune response. In this review we summarize the latest discoveries about the diverse functions of this multi-faceted protease. Recent studies revealed that among MBL-associated serine proteases, MASP-1 is the one responsible for triggering the lectin pathway via its ability to rapidly autoactivate then cleave MASP-2, and possibly MASP-3. The crystal structure of MASP-1 explains its more relaxed substrate specificity compared to the related complement enzymes. Due to the relaxed specificity, MASP-1 interacts with the coagulation cascade and the kinin generating system, and it can also activate endothelial cells eliciting pro-inflammatory signaling.
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Affiliation(s)
- József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary
| | - Verena Schroeder
- Department of Clinical Research, University of Bern, and University Clinic of Haematology, University Hospital, Bern, Switzerland
| | - Lorenz Jenny
- Department of Clinical Research, University of Bern, and University Clinic of Haematology, University Hospital, Bern, Switzerland
| | - László Cervenak
- 3rd Department of Internal Medicine, Semmelweis University, Kútvölgyi út 4, H-1125 Budapest, Hungary
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok krt. 2, H-1113 Budapest, Hungary.
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10
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Richardson VR, Schroeder V, Grant PJ, Standeven KF, Carter AM. Complement C3 is a substrate for activated factor XIII that is cross-linked to fibrin during clot formation. Br J Haematol 2012; 160:116-9. [PMID: 23078103 DOI: 10.1111/bjh.12096] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Howes JM, Richardson VR, Smith KA, Schroeder V, Somani R, Shore A, Hess K, Ajjan R, Pease RJ, Keen JN, Standeven KF, Carter AM. Complement C3 is a novel plasma clot component with anti-fibrinolytic properties. Diab Vasc Dis Res 2012; 9:216-25. [PMID: 22253322 DOI: 10.1177/1479164111432788] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND METHOD Increased plasma clot density and prolonged lysis times are associated with cardiovascular disease. In this study, we employed a functional proteomics approach to identify novel clot components which may influence clot phenotypes. RESULTS Analysis of perfused, solubilised plasma clots identified inflammatory proteins, including complement C3, as novel clot components. Analysis of paired plasma and serum samples confirmed concentration-dependent incorporation of C3 into clots. Surface plasmon resonance indicated high-affinity binding interactions between C3 and fibrinogen and fibrin. Turbidimetric clotting and lysis assays indicated C3 impaired fibrinolysis in a concentration-dependent manner, both in vitro and ex vivo. CONCLUSION These data indicate functional interactions between complement C3 and fibrin leading to prolonged fibrinolysis. These interactions are physiologically relevant in the context of protection following injury and suggest a mechanistic link between increased plasma C3 concentration and acute cardiovascular thrombotic events.
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Affiliation(s)
- Joanna-Marie Howes
- Division of Cardiovascular & Diabetes Research, Leeds Institute of Genetics Health & Therapeutics, University of Leeds, UK
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12
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Hess K, Ajjan R, Phoenix F, Dobó J, Gál P, Schroeder V. Effects of MASP-1 of the complement system on activation of coagulation factors and plasma clot formation. PLoS One 2012; 7:e35690. [PMID: 22536427 PMCID: PMC3335018 DOI: 10.1371/journal.pone.0035690] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/22/2012] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Numerous interactions between the coagulation and complement systems have been shown. Recently, links between coagulation and mannan-binding lectin-associated serine protease-1 (MASP-1) of the complement lectin pathway have been proposed. Our aim was to investigate MASP-1 activation of factor XIII (FXIII), fibrinogen, prothrombin, and thrombin-activatable fibrinolysis inhibitor (TAFI) in plasma-based systems, and to analyse effects of MASP-1 on plasma clot formation, structure and lysis. METHODOLOGY/PRINCIPAL FINDINGS We used a FXIII incorporation assay and specific assays to measure the activation products prothrombin fragment F1+2, fibrinopeptide A (FPA), and activated TAFI (TAFIa). Clot formation and lysis were assessed by turbidimetric assay. Clot structure was studied by scanning electron microscopy. MASP-1 activated FXIII and, contrary to thrombin, induced FXIII activity faster in the Val34 than the Leu34 variant. MASP-1-dependent generation of F1+2, FPA and TAFIa showed a dose-dependent response in normal citrated plasma (NCP), albeit MASP-1 was much less efficient than FXa or thrombin. MASP-1 activation of prothrombin and TAFI cleavage were confirmed in purified systems. No FPA generation was observed in prothrombin-depleted plasma. MASP-1 induced clot formation in NCP, affected clot structure, and prolonged clot lysis. CONCLUSIONS/SIGNIFICANCE We show that MASP-1 interacts with plasma clot formation on different levels and influences fibrin structure. Although MASP-1-induced fibrin formation is thrombin-dependent, MASP-1 directly activates prothrombin, FXIII and TAFI. We suggest that MASP-1, in concerted action with other complement and coagulation proteins, may play a role in fibrin clot formation.
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Affiliation(s)
- Katharina Hess
- Department of Internal Medicine, Cardiology, University Hospital Aachen, Aachen, Germany
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - Ramzi Ajjan
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - Fladia Phoenix
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
| | - József Dobó
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Budapest, Hungary
| | - Verena Schroeder
- Division of Cardiovascular and Diabetes Research, The LIGHT Laboratories, Multidisciplinary Cardiovascular Research Center, University of Leeds, Leeds, United Kingdom
- University Clinic of Hematology and Central Hematology Laboratory, Hemostasis Research Laboratory, University Hospital and University of Bern, Bern, Switzerland
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13
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Hess K, Alzahrani SH, Mathai M, Schroeder V, Carter AM, Howell G, Koko T, Strachan MWJ, Price JF, Smith KA, Grant PJ, Ajjan RA. A novel mechanism for hypofibrinolysis in diabetes: the role of complement C3. Diabetologia 2012; 55:1103-13. [PMID: 21918806 DOI: 10.1007/s00125-011-2301-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 08/12/2011] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS Impaired fibrin clot lysis is a key abnormality in diabetes and complement C3 is one protein identified in blood clots. This work investigates the mechanistic pathways linking C3 and hypofibrinolysis in diabetes using ex vivo/in vitro studies. METHODS Fibrinolysis and C3 plasma levels were determined in type 1 diabetic patients and healthy controls, and the effects of glycaemia investigated. C3 incorporation into fibrin clots and modulation of fibrinolysis were analysed by ELISA, immunoblotting, turbidimetric assays and electron and confocal microscopy. RESULTS Clot lysis time was longer in diabetic children than in controls (599 ± 18 and 516 ± 12 s respectively; p < 0.01), C3 levels were higher in diabetic children (0.55 ± 0.02 and 0.43 ± 0.02 g/l respectively; p < 0.01) and both were affected by improving glycaemia. An interaction between C3 and fibrin was confirmed by the presence of lower protein levels in sera compared with corresponding plasma and C3 detection in plasma clots by immunoblot. In a purified system, C3 was associated with thinner fibrin fibres and more prolongation of lysis time of clots made from fibrinogen from diabetic participants compared with controls (244 ± 64 and 92 ± 23 s respectively; p < 0.05). Confocal microscopy showed higher C3 incorporation into diabetic clots compared with controls, and fully formed clot lysis was prolonged by 764 ± 76 and 428 ± 105 s respectively (p < 0.05). Differences in lysis, comparing diabetes and controls, were not related to altered plasmin generation or C3-fibrinogen binding assessed by plasmon resonance. CONCLUSIONS/INTERPRETATION C3 incorporation into clots from diabetic fibrinogen is enhanced and adversely affects fibrinolysis. This may be one novel mechanism for compromised clot lysis in diabetes, potentially offering a new therapeutic target.
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Affiliation(s)
- K Hess
- University of Leeds, Leeds, UK
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14
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Carter AM. Complement activation: an emerging player in the pathogenesis of cardiovascular disease. SCIENTIFICA 2012; 2012:402783. [PMID: 24278688 PMCID: PMC3820556 DOI: 10.6064/2012/402783] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 11/06/2012] [Indexed: 05/08/2023]
Abstract
A wealth of evidence indicates a fundamental role for inflammation in the pathogenesis of cardiovascular disease (CVD), contributing to the development and progression of atherosclerotic lesion formation, plaque rupture, and thrombosis. An increasing body of evidence supports a functional role for complement activation in the pathogenesis of CVD through pleiotropic effects on endothelial and haematopoietic cell function and haemostasis. Prospective and case control studies have reported strong relationships between several complement components and cardiovascular outcomes, and in vitro studies and animal models support a functional effect. Complement activation, in particular, generation of C5a and C5b-9, influences many processes involved in the development and progression of atherosclerosis, including promotion of endothelial cell activation, leukocyte infiltration into the extracellular matrix, stimulation of cytokine release from vascular smooth muscle cells, and promotion of plaque rupture. Complement activation also influences thrombosis, involving components of the mannose-binding lectin pathway, and C5b-9 in particular, through activation of platelets, promotion of fibrin formation, and impairment of fibrinolysis. The participation of the complement system in inflammation and thrombosis is consistent with the physiological role of the complement system as a rapid effector system conferring protection following vessel injury. However, in the context of CVD, these same processes contribute to development of atherosclerosis, plaque rupture, and thrombosis.
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Affiliation(s)
- Angela M. Carter
- Division of Epidemiology, Leeds Institute of Genetics, Health and Therapeutics, Faculty of Medicine and Health and the Multidisciplinary Cardiovascular Research Centre, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK
- *Angela M. Carter:
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