scholarly journals Proteomic profiling of acute stent thrombi reveals critical involvement of the complement system

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T.M Hofbauer ◽  
K Distelmaier ◽  
A Bileck ◽  
A.S Ondracek ◽  
V Seidl ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Complement System ◽  
Proteomic Analysis ◽  
Gene Set Analysis ◽  
Funding Source ◽  
Complement Factor ◽  
Gene Set ◽  
All Cause Mortality ◽  
Factor C ◽  
The Complement System

Abstract Background Stent thrombosis (ST) is a severe complication after primary percutaneous coronary intervention (pPCI) and associated with significant morbidity and mortality. Apart from procedure- and lesion-related parameters and patient-related factors. However, the underlying molecular and cellular mechanisms of ST are still not fully understood. Purpose We aimed to perform in-depth proteomic analysis of ST to understand its pathogenesis. Methods We recruited 77 patients suffering from ST after pPCI for myocardial infarction (MI). As controls, we included matched patients suffering from native vessel acute myocardial infarction (NT, n=154). Five cases of acute ST (within 24 h) and six cases of NT thrombi aspirated from the culprit site were subjected to shotgun proteomic analysis. Gene-set analysis was employed to screen for pathways differing between ST and NT. All-cause mortality was assessed using Kaplan-Meier analysis. Results 9 patients presented with acute ST (<24 h, 11.7%), 18 patients with subacute ST (24 h to 30 days, 23.4%), 11 patients with late ST (30 days to 1 year, 14.3%) and 39 patients with very late ST (>1 year, 50.6%). ST was associated with increased all-cause mortality compared to NT (mean survival 129 vs. 109 months, log-rank p=0.032). We identified a total of 2438 proteins to be expressed in both ST and NT thrombi. Gene set analysis revealed the complement system to be highly active in acute ST compared to NT. Specifically, we found factors of both the classical (complement factor [C]1q, C1s) and alternative pathway (complement factor B) to be increased in ST, along with higher levels of C2, C3, C4a, C4b, C5, C8a and C9. Conclusion This hypothesis-generating study highlights a crucial role of the complement system in the pathogenesis of acute ST. Further studies are required to validate these findings in a larger cohort. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund

scholarly journals A novel approach to immunoapheresis of C3a/C3 and proteomic identification of associates

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8218
Author(s):  
Wolfgang Winnicki ◽  
Peter Pichler ◽  
Karl Mechtler ◽  
Richard Imre ◽  
Ines Steinmacher ◽  
...  
Keyword(s):  
Complement System ◽  
Proteomic Analysis ◽  
Methodological Approach ◽  
Central Component ◽  
Complement Factor ◽  
Immunoaffinity Column ◽  
Novel Approach ◽  
Human Disorders ◽  
Complement Factor C3 ◽  
The Complement System

Background Complement factor C3 represents the central component of the complement cascade and its activation split product C3a plays an important role in inflammation and disease. Many human disorders are linked to dysregulation of the complement system and alteration in interaction molecules. Therefore, various therapeutic approaches to act on the complement system have been initiated. Methods and Results Aiming to develop a tool to eliminate C3a/C3 from the circulation, in a first step a high affine murine monoclonal antibody (mAb) (3F7E2-mAb) was generated against complement factor C3 and selected for binding to the C3a region to serve as immunoaffinity reagent. Functional testing of the 3F7E2-mAb revealed an inhibition of Zymosan-induced cleavage of C3a from C3. Subsequently, a C3a/C3 specific 3F7E2-immunoaffinity column was developed and apheresis of C3a/C3 and associates was performed. Finally, a proteomic analysis was carried out for identification of apheresis products. C3a/C3 was liberated from the 3F7E2-column together with 278 proteins. C3a/C3 interaction specificity was validated by using a haptoglobin immunoaffinity column as control and biostatistic analysis revealed 39 true C3a/C3 interactants. Conclusion A novel and functionally active mAb was developed against complement factor C3a/C3 and used in a specific immunoaffinity column that allows apheresis of C3a/C3 and associates and their identification by proteomic analysis. This methodological approach of developing specific antibodies that can be used as immunoaffinity reagents to design immunoaffinity columns for elimination and further identification of associated proteins could open new avenues for the development of tailored immunotherapy in various complement-mediated or autoimmune diseases.

On the value of therapeutic interventions targeting the complement system in acute myocardial infarction

2017 ◽  
Vol 182 ◽  
pp. 103-122 ◽  
Author(s):  
Reindert W. Emmens ◽  
Diana Wouters ◽  
Sacha Zeerleder ◽  
S. Marieke van Ham ◽  
Hans W.M. Niessen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Complement System ◽  
Therapeutic Interventions ◽  
The Complement System

scholarly journals Functional expression of complement factor I following AAV-mediated gene delivery in the retina of mice and human cells

Gene Therapy ◽  
2021 ◽  
Author(s):  
Anna K. Dreismann ◽  
Michelle E. McClements ◽  
Alun R. Barnard ◽  
Elise Orhan ◽  
Jane P. Hughes ◽  
...  
Keyword(s):  
Complement System ◽  
Functional Expression ◽  
Geographic Atrophy ◽  
Age Related Macular Degeneration ◽  
Complement Factor ◽  
Factor I ◽  
Complement Factor I ◽  
Age Related ◽  
The Complement System

AbstractDry age-related macular degeneration (AMD) is characterised by loss of central vision and currently has no approved medical treatment. Dysregulation of the complement system is thought to play an important role in disease pathology and supplementation of Complement Factor I (CFI), a key regulator of the complement system, has the potential to provide a treatment option for AMD. In this study, we demonstrate the generation of AAV constructs carrying the human CFI sequence and expression of CFI in cell lines and in the retina of C57BL/6 J mice. Four codon optimised constructs were compared to the most common human CFI sequence. All constructs expressed CFI protein; however, most codon optimised sequences resulted in significantly reduced CFI secretion compared to the non-optimised CFI sequence. In vivo expression analysis showed that CFI was predominantly expressed in the RPE and photoreceptors. Secreted protein in vitreous humour was demonstrated to be functionally active. The findings presented here have led to the formulation of an AAV-vectored gene therapy product currently being tested in a first-in-human clinical trial in subjects with geographic atrophy secondary to dry AMD (NCT03846193).

scholarly journals Impact of chronic kidney disease on the relationship between vascular endothelial growth factor C and mortality in patients with suspected coronary artery disease: a subanalysis of the ANOX study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Wada ◽  
D Takagi ◽  
M Suzuki ◽  
M Matsuda ◽  
Y Ajiro ◽  
...  
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Funding Source ◽  
Vascular Endothelial ◽  
All Cause Mortality ◽  
Artery Disease ◽  
Cv Disease ◽  
Factor C ◽  
Endothelial Growth Factor ◽  
The Relationship

Abstract Background The lymphatic system has been suggested to play an important role in cholesterol metabolism and cardiovascular (CV) disease. Recently, we demonstrated that serum levels of vascular endothelial growth factor C (VEGF-C), a central player of lymphangiogenesis, are inversely and independently associated with the risk of all-cause mortality in patients with suspected or known coronary artery disease (CAD). However, the impact of chronic kidney disease (CKD) on the relationship between VEGF-C and mortality in patients with suspected CAD is unclear. Methods Serum VEGF-C levels were measured in 1,717 patients with suspected but no history of CAD undergoing elective coronary angiography, enrolled in the development of novel biomarkers related to angiogenesis or oxidative stress to predict CV events (ANOX) study, and followed up for 3 years. Patients were divided into 2 groups according to the presence (CKD, n=674) or absence (non-CKD, n=1,043) of CKD. The primary outcome was all-cause death. The secondary outcomes were CV death, and major adverse CV events (MACE) defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke. Results During the follow-up, 95 CKD and 66 non-CKD patients died from any cause, 37 CKD and 13 non-CKD died from CV disease, and 61 CKD and 43 non-CKD developed MACE. After adjustment for established risk factors, VEGF-C levels were significantly and inversely associated with all-cause death (hazard ratio [HR] for 1-SD increase, 0.72; 95% confidence interval [CI], 0.57–0.90) and CV death (HR, 0.69; 95% CI, 0.48–0.97), but not with MACE (HR, 0.78; 95% CI, 0.60–1.03) in CKD, while VEGF-C levels were significantly and inversely associated with all-cause death (HR, 0.69; 95% CI, 0.52–0.91), but not with CV death (HR, 0.91; 95% CI, 0.50–1.66) or MACE (HR, 1.09; 95% CI, 0.81–1.44) in non-CKD. Even after incorporation of N-terminal pro-brain natriuretic peptide, contemporary sensitive cardiac troponin I, and high-sensitivity C-reactive protein into a model with established risk factors, the addition of VEGF-C levels further improved the prediction of all-cause death (P=0.047 for continuous net reclassification improvement [NRI], P=0.048 for integrated discrimination improvement [IDI]), but not that of CV death (P=0.016 for NRI, P=0.245 for IDI) or MACE (P=0.166 for NRI, P=0.311 for IDI) in CKD, whereas the addition of VEGF-C levels did not improve the prediction of all-cause death (P=0.053 for NRI, P=0.012 for IDI), CV death (P=0.864 for NRI, P=0.602 for IDI) or MACE (P=0.999 for NRI, P=0.154 for IDI) in non-CKD. Conclusions The VEGF-C level inversely and independently predicted all-cause mortality in CKD, but not in non-CKD patients with suspected CAD. The inverse relationship between VEGF-C and all-cause mortality in patients with suspected CAD seems to be remarkable in the presence of CKD. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

The mechanism of supply-demand imbalance and clinical outcomes in patients with type 2 myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Bularga ◽  
A Anand ◽  
F.E Strachan ◽  
K.K Lee ◽  
S Stewart ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Coronary Syndrome ◽  
Clinical Outcomes ◽  
Controlled Trial ◽  
Funding Source ◽  
Coronary Syndrome ◽  
All Cause Mortality ◽  
Randomised Controlled

Abstract Background Type 2 myocardial infarction is common and associated with substantial risk of adverse clinical outcomes, worse than type 1 myocardial infarction, with as few as 30% of patients still alive at five years. However, this broad diagnostic term encompasses multiple mechanisms of supply-demand imbalance, which may be associated with different risks of adverse outcomes. Purpose We aimed to assess the prevalence and clinical outcomes of different mechanisms of supply-demand imbalance related to survival in the High-STEACS (High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial. Methods The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland, including 48,282 consecutive patients with suspected acute coronary syndrome. The diagnosis was adjudicated according to the Fourth Universal Definition of Myocardial Infarction. In patients with type 2 myocardial infarction, we prospectively adjudicated the cause for supply demand imbalance. Linkage of electronic healthcare records was used to track investigation, treatments and clinical outcomes. We used the Kaplan-Meier method, the log rank test and cox regression models adjusted for age, sex, renal function and co-morbidities to evaluate the risk of future all-cause mortality between categories. Results We identified 1,121 patients with type 2 myocardial infarction (age 74- ± 14, 55% female). At one year, death from any cause occurred in 23% (258/1,121) of patients. The most common reason for supply-demand imbalance was tachyarrhythmia in 55% (616/1,121), followed by hypoxaemia in 20% (219/1,121) of patients. Tachyarrhythmia was associated with reduced future risk of all-cause mortality (adjusted HR 0.69, 95% CI 0.43–1.09), similar to those with type 1 myocardial infarction. Comparatively, patients with hypoxaemia appeared at highest risk (adjusted HR 1.75, 95% CI 1.09–2.80). Conclusion The mechanism of myocardial oxygen supply-demand imbalance is associated with future prognosis, and should be considered when risk stratifying patients with type 2 myocardial infarction. Supply-demand imbalance survival Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Reduced Mannose-Binding Lectin-Associated Serine Protease (MASP)-1 is Associated with Disturbed Coagulation in Septic Shock

2019 ◽  
Vol 119 (06) ◽  
pp. 952-961 ◽  
Author(s):  
Julie Brogaard Larsen ◽  
Mathies Appel Laursen ◽  
Christine Lodberg Hvas ◽  
Kim Michael Larsen ◽  
Steffen Thiel ◽  
...  
Keyword(s):  
Septic Shock ◽  
Complement System ◽  
Sofa Score ◽  
Thrombin Generation ◽  
Mannose Binding Lectin ◽  
Lectin Pathway ◽  
Complement Factor ◽  
Mannose Binding ◽  
The Complement System ◽  
Binding Lectin

Background Activation of the complement system is part of the dysregulated immune response in sepsis. The mannose-binding lectin-associated serine proteases (MASP)-1 and -2 activate the lectin pathway of the complement system. Besides, these proteins can activate coagulation in vitro. However, the role of the lectin pathway proteins in the development of sepsis-related disseminated intravascular coagulation (DIC) is only sparsely investigated. Aim This article investigates the association between lectin pathway proteins and coagulation disturbances in septic shock patients. Materials and Methods We included 36 septic shock patients from the intensive care unit, Aarhus University Hospital, Denmark. Blood samples were obtained within 24 hours after admission (day 1), and subsequently on day 2 and day 3. Plasma concentrations of mannose-binding lectin (MBL), H-ficolin, M-ficolin, CL-L1, CL-K1, MASP-1, -2 and -3, MBL-associated proteins of 19 and 44 kDa as well as complement factor C3dg were assessed. Standard coagulation parameters, thrombin generation, thrombin–anti-thrombin (TAT) complex and pro-thrombin fragment 1 + 2 were measured. Sequential Organ Failure Assessment (SOFA) score, DIC score and 30-day mortality were assessed. Results Reduced MASP-1 plasma concentration was associated with DIC score ≥5 (p = 0.02), impaired thrombin generation (p = 0.03) and lower plasma TAT complex levels (p = 0.03). No association was found between lectin pathway proteins and SOFA score or 30-day mortality. Conclusion Reduced MASP-1 concentrations were associated with impaired coagulation in septic shock patients. This indicates that increased MASP-1 activation and consumption is associated with the more severe coagulation disturbances in sepsis and points to a possible role for MASP-1 in sepsis-related DIC.

scholarly journals Role of the Classical Pathway of Complement Activation in Experimentally Induced Polymicrobial Peritonitis

2001 ◽  
Vol 69 (12) ◽  
pp. 7304-7309 ◽  
Author(s):  
Ilhan Celik ◽  
Cordula Stover ◽  
Marina Botto ◽  
Steffen Thiel ◽  
Sotiria Tzima ◽  
...  
Keyword(s):  
Complement System ◽  
Complement Activation ◽  
Immune Defense ◽  
Classical Pathway ◽  
Complement Factor ◽  
Wild Type ◽  
Factor B ◽  
The Complement System ◽  
Deficient Mice

ABSTRACT The complement system and the natural antibody repertoire provide a critical first-line defense against infection. The binding of natural antibodies to microbial surfaces opsonizes invading microorganisms and activates complement via the classical pathway. Both defense systems cooperate within the innate immune response. We studied the role of the complement system in the host defense against experimental polymicrobial peritonitis using mice lacking either C1q or factor B and C2. The C1q-deficient mice lacked the classical pathway of complement activation. The factor B- and C2-deficient mice were known to lack the classical and alternative pathways, and we demonstrate here that these mice also lacked the lectin pathway of complement activation. Using inoculum doses adjusted to cause 42% mortality in the wild-type strain, none of the mice deficient in the three activation routes of complement (factor B and C2 deficient) survived (mortality of 100%). Mortality in mice deficient only in the classical pathway of complement activation (C1q deficient) was 83%. Application of further dilutions of the polymicrobial inoculum showed a dose-dependent decrease of mortality in wild-type controls, whereas no changes in mortality were observed in the two gene-targeted strains. These results demonstrate that the classical activation pathway is required for an effective antimicrobial immune defense in polymicrobial peritonitis and that, in the infection model used, the remaining antibody-independent complement activation routes (alternative and lectin pathways) provide a supporting line of defense to gain residual protection in classical pathway deficiency.

scholarly journals Complement in Lupus Nephritis: New Perspectives

2015 ◽  
Vol 1 (2) ◽  
pp. 91-99 ◽  
Author(s):  
Lihua Bao ◽  
Patrick N. Cunningham ◽  
Richard J. Quigg
Keyword(s):  
Lupus Nephritis ◽  
Complement System ◽  
Complement Activation ◽  
Autoimmune Disorder ◽  
Factor H ◽  
Complement Factor ◽  
Dual Roles ◽  
Increased Risk ◽  
Wide Range ◽  
The Complement System

Background: Systemic lupus erythematosus (SLE) is an autoimmune disorder caused by loss of tolerance to self-antigens, the production of autoantibodies and deposition of complement-fixing immune complexes (ICs) in injured tissues. SLE is characterized by a wide range of clinical manifestations and targeted organs, with lupus nephritis being one of the most serious complications. The complement system consists of three pathways and is tightly controlled by a set of regulatory proteins to prevent injudicious complement activation on host tissue. The involvement of the complement system in the pathogenesis of SLE is well accepted; yet, its exact role is still not clear. Summary: Complement plays dual roles in the pathogenesis of SLE. On the one hand, the complement system appears to have protective features in that hereditary homozygous deficiencies of classical pathway components, such as C1q and C4, are associated with an increased risk for SLE. On the other hand, IC-mediated activation of complement in affected tissues is clearly evident in both experimental and human SLE along with pathological features that are logical consequences of complement activation. Studies in genetically altered mice have shown that lack of complement inhibitors, such as complement factor H (CFH) or decay-accelerating factor (DAF) accelerates the development of experimental lupus nephritis, while treatment with recombinant protein inhibitors, such as Crry-Ig, CR2-Crry, CR2-DAF and CR2-CFH, ameliorates the disease development. Complement-targeted drugs, including soluble complement receptor 1 (TP10), C1 esterase inhibitor and a monoclonal anti-C5 antibody (eculizumab), have been shown to inhibit complement safely, and are now being investigated in a variety of clinical conditions. Key Messages: SLE is an autoimmune disorder which targets multiple systems. Complement is centrally involved and plays dual roles in the pathogenesis of SLE. Studies from experimental lupus models and clinical trials support the use of complement-targeted therapy in the treatment of SLE.

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