The contact system is a potent procoagulant and proinflammatory plasma protease cascade that is initiated by binding (“contact”)-induced, auto-activation of factor XII zymogen. Formed active serine ...protease FXIIa then cleaves plasma prekallikrein to kallikrein that in turn liberates the mediator bradykinin from its precursor high molecular weight kininogen. Bradykinin induces inflammation with implications for host defense and innate immunity. FXIIa also triggers the intrinsic pathway of coagulation that has been shown to critically contribute to thrombosis. Vice versa, FXII deficiency impairs thrombosis in animal models without inducing abnormal excessive bleeding. Recent work has established the FXIIa-driven contact system as promising target for anticoagulant and anti-inflammatory drugs. This review focuses on the biochemistry of the contact system, its regulation by endogenous and exogenous inhibitors, and roles in disease states. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
•The contact system is a procoagulant & proinflammatory plasma protease cascade, driven by activated factor XII (FXIIa)•The serine protease FXIIa triggers the kallikrein kinin-system that generates the inflammatory mediator bradykinin•Excess bradykinin production due to defective FXIIa regulation underlies the inherited swelling disease Hereditary angioedema•FXIIa critically contributes to thrombosis via the intrinsic pathway of coagulation but has no role for hemostasis•Targeting FXIIa provides thromboprotection without impairing hemostasis with additional anti-inflammatory activities
Anaphylaxis is a life-threatening allergic reaction. It is triggered by the release of pro-inflammatory cytokines and mediators from mast cells and basophils in response to immunologic or ...non-immunologic mechanisms. Mediators that are released upon mast cell activation include the highly sulfated polysaccharide and inorganic polymer heparin and polyphosphate (polyP), respectively. Heparin and polyP supply a negative surface for factor XII (FXII) activation, a serine protease that drives contact system-mediated coagulation and inflammation. Activation of the FXII substrate plasma kallikrein leads to further activation of zymogen FXII and triggers the pro-inflammatory kallikrein-kinin system that results in the release of the mediator bradykinin (BK). The severity of anaphylaxis is correlated with the intensity of contact system activation, the magnitude of mast cell activation, and BK formation. The main inhibitor of the complement system, C1 esterase inhibitor, potently interferes with FXII activity, indicating a meaningful cross-link between complement and kallikrein-kinin systems. Deficiency in a functional C1 esterase inhibitor leads to a severe swelling disorder called hereditary angioedema (HAE). The significance of FXII in these disorders highlights the importance of studying how these processes are integrated and can be therapeutically targeted. In this review, we focus on how FXII integrates with inflammation and the complement system to cause anaphylaxis and HAE as well as highlight current diagnosis and treatments of BK-related diseases.
Background Coronary heart disease is a leading cause of mortality worldwide. Iron deficiency, a frequent comorbidity of coronary heart disease, causes an increased expression of transferrin receptor ...and soluble transferrin receptor levels (sTfR) levels, while iron repletion returns sTfR levels to the normal physiological range. Recently, sTfR levels were proposed as a potential new marker of iron metabolism in cardiovascular diseases. Therefore, we aimed to evaluate the prognostic value of circulating sTfR levels in a large cohort of patients with coronary heart disease. Methods and Results The disease cohort comprised 3423 subjects who had angiographically documented coronary heart disease and who participated in the AtheroGene study. Serum levels of sTfR were determined at baseline using an automated immunoassay (Roche Cobas Integra 400). Two main outcomes were considered: a combined end point of myocardial infarction and cardiovascular death and cardiovascular death alone. During a median follow-up of 4.0 years, 10.3% of the patients experienced an end point. In Cox regression analyses for sTfR levels, the hazard ratio (HR) for future cardiovascular death and/or myocardial infarction was 1.27 (95% CI, 1.11-1.44,
<0.001) after adjustment for sex and age. This association remained significant (HR, 1.23; 95% CI, 1.03-1.46,
=0.02) after additional adjustment for body mass index, smoking status, hypertension, diabetes mellitus, dyslipidemia, C-reactive protein, and surrogates of cardiac function, size of myocardial necrosis (hs-Tnl), and hemoglobin levels. Conclusions In this large cohort study, sTfR levels were strongly associated with future myocardial infarction and cardiovascular death. This implicates a role for sTfR in secondary cardiovascular risk prediction.
Smoking is a risk factor for atherosclerosis with reported widespread effects on gene expression in circulating blood cells. We hypothesized that a molecular signature mediating the relation between ...smoking and atherosclerosis may be found in the transcriptome of circulating monocytes. Genome-wide expression profiles and counts of atherosclerotic plaques in carotid arteries were collected in 248 smokers and 688 non-smokers from the general population. Patterns of co-expressed genes were identified by Independent Component Analysis (ICA) and network structure of the pattern-specific gene modules was inferred by the PC-algorithm. A likelihood-based causality test was implemented to select patterns that fit models containing a path "smoking→gene expression→plaques". Robustness of the causal inference was assessed by bootstrapping. At a FDR ≤0.10, 3,368 genes were associated to smoking or plaques, of which 93% were associated to smoking only. SASH1 showed the strongest association to smoking and PPARG the strongest association to plaques. Twenty-nine gene patterns were identified by ICA. Modules containing SASH1 and PPARG did not show evidence for the "smoking→gene expression→plaques" causality model. Conversely, three modules had good support for causal effects and exhibited a network topology consistent with gene expression mediating the relation between smoking and plaques. The network with the strongest support for causal effects was connected to plaques through SLC39A8, a gene with known association to HDL-cholesterol and cellular uptake of cadmium from tobacco, while smoking was directly connected to GAS6, a gene reported to have anti-inflammatory effects in atherosclerosis and to be up-regulated in the placenta of women smoking during pregnancy. Our analysis of the transcriptome of monocytes recovered genes relevant for association to smoking and atherosclerosis, and connected genes that before, were only studied in separate contexts. Inspection of correlation structure revealed candidates that would be missed by expression-phenotype association analysis alone.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cardiovascular diseases (CVDs) comprise 45% of all deaths in Europe and causes 3.9 million deaths annually. Coronary artery disease (CAD) which includes myocardial infarction (MI) represents the most ...common form of CVD. A relevant proportion of MI cases seems preventable since reports claim that up to two-thirds of these patients exhibit symptoms suggestive for MI within 12 months prior to the acute MI event. An early identification of these at-risk subjects is necessary to manage an early and efficient treatment during the ischemic phase. The aim of the PRecision MEDicine in Coronary Artery Disease (PREMED-CAD) consortium is to apply a system medicine approach towards studying and identifying an ischemia specific 'biomarker signature' that improves the identification of individuals 'at-risk' for acute MI. The consortium will take an interdisciplinary and translational approach integrating knowledge from CAD epidemiology, imaging, bioinformatics, statistics and molecular biology, as well as existing phenotypic, blood-based and clinical biomarker data of distinct CAD and subclinical MI phenotypes. This biomarker signature will be validated through atherosclerosis-prone mouse models and human cohorts. The validated signature will be translated in a real-world clinical setting using an ongoing clinical trial comprising patients with subclinical ischemia. The aim of the knowledge obtained from this project is to aid in early MI detection and reduce the mortality and morbidity rate in these at-risk MI individuals.
Abstract Objective We have previously reported that SASH1 expression is increased in circulating human monocytes from smokers and was positively correlated with the number of carotid atherosclerotic ...plaques. The aim of this study was to further validate the link between smoking, SASH1 and atherosclerosis within the vascular wall and to assess the impact of SASH1 expression on endothelial cell functions. Method Human carotids with atherosclerotic plaques were obtained from 58 patients (45 of them with known smoking status: smoker, non-smoker, ex-smokers), and were processed for gene expression analyses and immunostaining. To investigate its function, SASH1 was silenced in human aortic endothelial cells (HAECs) using two different siRNA and subcellular localization of SASH1 was determined by immunostaining and subcellular fractionation. Subsequently the transcriptomic analyses and functional experiments (wound healing, WST-1 proliferation or Matrigel assays) were performed to characterize SASH1 function. Results SASH1 was expressed in human vascular cells (HAECs, smooth muscle cells) and in monocytes/macrophages. Its tissue expression was significantly higher in the atherosclerotic carotids of smokers compared to non-smokers (p < 0.01). In HAECs, SASH1 was expressed mostly in the cytoplasm and SASH1 knockdown resulted in an increased cell migration, proliferation and angiogenesis. Transcriptomic and pathway analyses showed that SASH1 silencing results in a decreased CYP1A1 expression possibly through the inhibition of TP53 activity. Conclusion We showed that SASH1 expression is increased in atherosclerotic carotids in smokers and its silencing affects endothelial angiogenic functions; therefore we provide a potential link between smoking and atherosclerosis through SASH1 expression.
Lipid phosphate phosphatase 3; type 2 phosphatidic acid phosphatase β (LPP3; PPAP2B) is a transmembrane protein dephosphorylating and thereby terminating signalling of lipid substrates including ...lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P). Human LPP3 possesses a cell adhesion motif that allows interaction with integrins. A polymorphism (rs17114036) in PPAP2B is associated with coronary artery disease, which prompted us to investigate the possible role of LPP3 in human endothelial dysfunction, a condition promoting atherosclerosis.
To study the role of LPP3 in endothelial cells we used human primary aortic endothelial cells (HAECs) in which LPP3 was silenced or overexpressed using either wild type or mutated cDNA constructs. LPP3 silencing in HAECs enhanced secretion of inflammatory cytokines, leucocyte adhesion, cell survival, and migration and impaired angiogenesis, whereas wild-type LPP3 overexpression reversed these effects and induced apoptosis. We also demonstrated that LPP3 expression was negatively correlated with vascular endothelial growth factor expression. Mutations in either the catalytic or the arginine-glycine-aspartate (RGD) domains impaired endothelial cell function and pharmacological inhibition of S1P or LPA restored it. LPA was not secreted in HAECs under silencing or overexpressing LPP3. However, the intra- and extra-cellular levels of S1P tended to be correlated with LPP3 expression, indicating that S1P is probably degraded by LPP3.
We demonstrated that LPP3 is a negative regulator of inflammatory cytokines, leucocyte adhesion, cell survival, and migration in HAECs, suggesting a protective role of LPP3 against endothelial dysfunction in humans. Both the catalytic and the RGD functional domains were involved and S1P, but not LPA, might be the endogenous substrate of LPP3.
Background & Aims The tumor-suppressor sterile α motif– and Src-homology 3–domain containing 1 (SASH1) has clinical relevance in colorectal carcinoma and is associated specifically with metachronous ...metastasis. We sought to identify the molecular mechanisms linking decreased SASH1 expression with distant metastasis formation. Methods SASH1-deficient, SASH1-depleted, or SASH1-overexpressing HCT116 colon cancer cells were generated by the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9-method, RNA interference, and transient plasmid transfection, respectively. Epithelial-mesenchymal transition (EMT) was analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblotting, immunofluorescence microscopy, migration/invasion assays, and 3-dimensional cell culture. Yeast 2-hybrid assays and co-immunoprecipitation/mass-spectrometry showed V-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) as a novel interaction partner of SASH1, further confirmed by domain mapping, site-directed mutagenesis, co-immunoprecipitation, and dynamic mass redistribution assays. CRKL-deficient cells were generated in parental or SASH1-deficient cells. Metastatic capacity was analyzed with an orthotopic mouse model. Expression and significance of SASH1 and CRKL for survival and response to chemotherapy was assessed in patient samples from our department and The Cancer Genome Atlas data set. Results SASH1 expression is down-regulated during cytokine-induced EMT in cell lines from colorectal, pancreatic, or hepatocellular cancer, mediated by the putative SASH1 promoter. Deficiency or knock-down of SASH1 induces EMT, leading to an aggressive, invasive phenotype with increased chemoresistance. SASH1 counteracts EMT through interaction with the oncoprotein CRKL, inhibiting CRKL-mediated activation of SRC kinase, which is crucially required for EMT. SASH1-deficient cells form significantly more metastases in vivo, depending entirely on CRKL. Patient tumor samples show significantly decreased SASH1 and increased CRKL expression, associated with significantly decreased overall survival. Patients with increased CRKL expression show significantly worse response to adjuvant chemotherapy. Conclusions We propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation.
L’athérosclérose est caractérisée par l’accumulation de lipides dans les artères de gros et moyen calibre. Cette accumulation est due à une série de mécanismes complexes aboutissant a une réaction ...inflammatoire chronique et l’accumulation de cellules spumeuse dans l’espace neointimale de la paroi vasculaire. Les complications liées à cette pathologie peuvent entraîner des événements vasculaires graves, tels que l’infarctus du myocarde ou les accidents vasculaires cérébraux. Nos travaux de recherches s’inscrivent dans le cadre de la Gutenberg Health Study, une étude de population dans la région de Mayence (Mainz) en Allemagne, dont le but est d’identifier de nouveaux marqueurs biologiques et cibles thérapeutiques liées aux maladies cardiovasculaires, avec un accent particulier sur l’athérosclérose. Nos précédents travaux ont démontré que l’expression de certains gènes dans les monocytes circulants était corrélée à la fois au tabagisme et à l’athérosclérose, ouvrant ainsi de nouvelles perspectives pour expliquer les mécanismes par lesquels le tabagisme accélère la formation des plaques d’athérosclérose. Parmi ces gènes, SASH1, un gène suppresseur de tumeur était le plus corrélé au tabagisme, tout en étant également corrélé au nombre de plaques. Un autre gène, SLC39A8, montrait la plus forte corrélation avec le nombre de plaque. Mon travail de thèse a consisté à explorer le rôle de SASH1, un gène suppresseur de tumeur, et SLC39A8, un symporteur HCO3-/ion métallique divalent, in vitro pour tenter de déterminer par quels mécanismes cellulaires et moléculaires ils pouvaient affecter la formation de la plaque d’athérosclérose. L’étude sur SASH1 porte en particulier sur la paroi vasculaire où SASH1 a été détectée dans toutes les cellules présentes (cellules endothéliales, cellules musculaires lisses, monocytes et macrophages). De plus, des mesures en RT-qPCR ont montré que l’expression de SASH1 était plus élevée dans les carotides de fumeurs que dans celles des non-fumeurs et ex-fumeurs, confirmant ainsi les observations déjà faites dans les monocytes circulants humains...
Atherosclerosis is characterized by lipids accumulation in medium and big size arteries, as the result of a complex series of mechanisms leading to chronic inflammation and accumulation of macrophage-derived foam cells in the intimal space of the vessels leading to atherosclerotic plaque formation. Rupture of the plaque can lead to life threatening events, such as myocardial infarction and stroke. Our scientific work is in the frame of the Gutenberg Health Study, a population based study in the region of Mainz in Germany, which goal is to identify new biological markers and therapeutic targets, with a particular focus on atherosclerosis. These previous studies have shown through transcriptomic analyses that a number of gene expression were correlated to both smoking and atherosclerosis, opening new perspective to better characterize mechanisms linking smoking to atherosclerosis. Among those genes SASH1, a tumor suppressor was the most correlated to smoking and was also correlated to plaques. Another gene of interest, SLC39A8 showed the strongest correlation to plaques. This thesis project aimed at exploring the role of the tumor suppressor SASH1 and the metallic ion transporter in vitro to determine the cellular and molecular mechanisms by which they could affect plaque formation during atherosclerosis...
Background & Aims: The tumor-suppressor sterile α motif– and Src-homology 3–domain containing 1 (SASH1) has clinical relevance in colorectal carcinoma and is associated specifically with metachronous ...metastasis. We sought to identify the molecular mechanisms linking decreased SASH1 expression with distant metastasis formation. Methods: SASH1-deficient, SASH1-depleted, or SASH1-overexpressing HCT116 colon cancer cells were generated by the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9-method, RNA interference, and transient plasmid transfection, respectively. Epithelial-mesenchymal transition (EMT) was analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblotting, immunofluorescence microscopy, migration/invasion assays, and 3-dimensional cell culture. Yeast 2-hybrid assays and co-immunoprecipitation/mass-spectrometry showed V-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) as a novel interaction partner of SASH1, further confirmed by domain mapping, site-directed mutagenesis, co-immunoprecipitation, and dynamic mass redistribution assays. CRKL-deficient cells were generated in parental or SASH1-deficient cells. Metastatic capacity was analyzed with an orthotopic mouse model. Expression and significance of SASH1 and CRKL for survival and response to chemotherapy was assessed in patient samples from our department and The Cancer Genome Atlas data set. Results: SASH1 expression is down-regulated during cytokine-induced EMT in cell lines from colorectal, pancreatic, or hepatocellular cancer, mediated by the putative SASH1 promoter. Deficiency or knock-down of SASH1 induces EMT, leading to an aggressive, invasive phenotype with increased chemoresistance. SASH1 counteracts EMT through interaction with the oncoprotein CRKL, inhibiting CRKL-mediated activation of SRC kinase, which is crucially required for EMT. SASH1-deficient cells form significantly more metastases in vivo, depending entirely on CRKL. Patient tumor samples show significantly decreased SASH1 and increased CRKL expression, associated with significantly decreased overall survival. Patients with increased CRKL expression show significantly worse response to adjuvant chemotherapy. Conclusions: We propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation. Keywords: EMT, Tumor Suppressor, SRC-Kinase, Chemoresistance
PDF
