Accumulating evidence points towards a role for proteases and protease inhibitors in tissue remodelling and repair in a variety of organs. In particular-besides the matrix metalloprotease system-the ...plasminogen activator (PA)/plasmin system has been implicated in these processes in the heart. Urokinase type PA (u-PA) and PA inhibitor type 1 (PAI-1) seem to modulate cardiac rupture and infarct healing. In this study we aimed to investigate whether inflammatory mediators can regulate the expression of components of the PA/plasmin system in human adult cardiac myocytes (HACM). We could demonstrate that HACM, isolated from pieces of myocardial tissue by mechanical dispersion and characterized by positive immunostaining for the cardiac markers troponin I, tropomyosin, cardiotin and myocardial muscle-actin, in vitro express PAI-1 and tissue type PA (t-PA) whereas u-PA was not detectable in these cells. PAI-1 protein production was increased up to twofold by interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) and up to fivefold by transforming growth factor-beta (TGF-beta) and oncostatin M (OSM). Similar changes were observed in PAI-1 transcript levels after cytokine treatment. t-PA production in HACM was not affected by these agonists. No effect of these cytokines on PAI-1 production in fibroblasts isolated from human myocardial tissue was seen. In an ex vivo model we could show that incubation of pieces of human myocardial tissue with these cytokines also resulted in an increase in PAI-1 in cardiac myocytes as evidenced by immuno-histochemistry. Furthermore we found increased PAI-1 expression in myocardial tissue from a patient suffering from acute myocarditis. Thus for the first time we provide evidence that inflammatory mediators modulate PAI-1 expression in human adult cardiac myocytes in vitro and ex vivo and could demonstrate that PAI-1 expression is increased in the in vivo setting under inflammatory conditions. If the effect on PAI-1 expression brought about by IL-1alpha, TNF-alpha, TGF-beta and OSM is not only operative under in vitro and ex vivo conditions but also in the in vivo setting one could speculate that these cytokines contribute to upregulation of PAI-1 in myocardial tissue and that PAI-1, when upregulated in myocardial tissue during inflammatory processes, could serve as a defence mechanism against excessive matrix degradation by proteases. Thus we propose a role for PAI-1 produced in the heart by cardiac myocytes in cardiac remodelling and repair processes.
Recent data suggest that auricular thrombosis is associated with accumulation of mast cells (MC) in the upper endocardium (where usually no MC reside) and local expression of MGF (mast cell growth ...factor) (25). In this study, the role of vascular cells, thrombin-activation and MGF, in MC-migration was analyzed. For this purpose, cultured human auricular endocardial cells (HAUEC), umbilical vein endothelial cells (HUVEC) and uterine- (HUTMEC) and skin-derived (HSMEC) microvascular endothelial cells were exposed to thrombin or control medium, and the migration of primary tissue MC (lung, n = 6) and HMC-1 cells (human MC-line) against vascular cells (supernatants) measured. Supernatants (24 h) of unstimulated vascular cells (monolayers of endocardium or endothelium) as well as recombinant (rh) MGF induced a significant migratory response in HMC-1 (control: 3025 +/- 344 cells 100 +/- 11.4% vs. MGF, 100 ng/ml: 8806 +/- 1019 291 +/- 34% vs. HAUEC: 9703 +/- 1506 320.8 +/- 49.8% vs. HUTMEC: 8950 +/- 1857 295.9 +/- 61.4% vs. HSMEC: 9965 +/- 2018 329.4 +/- 66.7% vs. HUVEC: 9487 +/- 1402 313.6 +/- 46.4%, p < 0.05) as well as in primary lung MC. Thrombin-activation (5 U/ml, 12 h) of vascular cells led to an augmentation of the directed migration of MC as well as to a hirudin-sensitive increase in MGF synthesis and release. Moreover, a blocking anti-MGF antibody was found to inhibit MC-migration induced by unstimulated or thrombin-activated vascular cells. Together, these data show that endocardial and other vascular cells can induce migration of human MC. This MC-chemotactic signal of the vasculature is associated with expression and release of MGF, augmentable by thrombin, and may play a role in the pathophysiology of (auricular) thrombosis.
Increased expression of plasminogen activator inhibitor-1 (PAI-1) mRNA in atherosclerotic human arteries suggests a linkage between PAI-1 gene expression and cellular proliferation, the fundamental ...feature of atherosclerosis. To investigate whether smooth muscle cell (SMC) proliferation influences overall fibrinolytic properties of the vascular wall, we examined the effect of serial in vitro passaging of human SMCs on tissue plasminogen activator (TPA) and PAI-1 synthesis levels as well as the ability to modulate TPA and PAI-1 synthesis of human umbilical vein endothelial cells (HUVECs). As in vivo correlates for such late-passage cells in culture, SMCs derived from human atherosclerotic plaques were used, because they are thought to have already undergone numerous cell doublings. We observed an increase of PAI-1 secretion (from 591 +/- 106 to 2952 +/- 290 ng PAI-1.10(5) cells-1.24 h-1) with a concomitant fourfold to fivefold increase of PAI-1 mRNA levels, as well as a decrease of TPA secretion (from 118 +/- 34 to 8 +/- 1.3 ng TPA.10(5) cells-1.24 h-1) and a twofold to threefold decrease of TPA mRNA levels with increasing in vitro passage number (from passage 3 to 11) of normal pulmonary artery smooth muscle cells (PASMCs) (P < .05). SMCs derived from atherosclerotic plaques of coronary arteries (CASMCs) displayed higher levels of PAI-1 antigen synthesis (3093 +/- 507 ng PAI-1.10(5) cells-1.24 h-1) with an approximately twofold increase of PAI-1 mRNA levels, as well as decreased levels of TPA antigen synthesis (10 +/- 1.6 ng TPA.10(5) cells-1.24 h-1) with an approximately 1.5- to 2-fold decrease of TPA mRNA levels in passage 1, compared with their counterparts derived from normal-appearing arterial tissue of the same vessel (1794 +/- 525 ng PAI-1.10(5) cells-1.24 h-1; 17 +/- 5 ng TPA.10(5) cells-1.24 h-1) (P < .001; P < .01). Incubation of HUVEC cultures with the 24-hour conditioned media (CM) of early-passage PASMCs decreased endothelial PAI-1 antigen synthesis by approximately 42% (P < .001) and endothelial PAI-1 mRNA levels about twofold to threefold (P < .001), whereas by incubation with the 24-hour CM of late-passage PASMCs, endothelial PAI-1 antigen synthesis was upregulated by 68% (P = .001), with a concomitant twofold increase of endothelial PAI-1 mRNA levels (P < .001). The apparent MW of this heat- and acid-stable PAI-1 upregulating factor appears to be between 50 and 100 kD, as judged by ultrafiltration. Incubation of HUVEC cultures with the 24-hour CM of early-passage CASMCs derived from normal-appearing arterial tissue showed no significant influence on endothelial PAI-1 synthesis, whereas incubation with late-passage normal CASMCs, as well as early-passage atherosclerotic CASMCs from the same vessel, increased endothelial PAI-1 antigen secretion by 45% and 48% (P < .001), with a concomitant 1.5 fold to 2-fold increase of endothelial PAI-1 mRNA levels (P < .05). No significant change in endothelial TPA synthesis was observed by incubation with CM of either PASMCs (early or late passage) or CASMCs (atherosclerotic or normal). These data suggest that SMC proliferation is associated with (1) increased SMC PAI-1 synthesis as well as decreased TPA synthesis and (2) upregulation of endothelial PAI-1 synthesis by SMC CM. This phenomenon is observed with either late passages of normal PASMCs and CASMCs or early passages of atherosclerotic plaque CASMCs. This suggests that proliferating SMCs are a major regulator of the fibrinolytic potential within the vessel wall, thereby contributing to the thrombotic risk associated with the development of atherosclerosis.
Antithrombin (AT) is the physiological inhibitor of thrombin or other serine proteases of coagulation cascades. AT is also known to regulate inflammatory reactions. To determine whether AT inhibits ...cytokine-induced endothelial activation, we examined the effect of AT on an increase in endothelial cell adhesion molecules E-selectin and intercellular adhesion molecule-1 induced by tumor necrosis factor (TNF)-α. AT inhibited increase in E-selectin and intercellular adhesion molecule-1 expression induced by tumor necrosis factor-α. AT inhibited neither IκB degradation, nuclear translocation of NF-κB, nor nuclear binding activity of NF-κB. This suggests that AT did not inhibit the NF-κB pathway. AT inhibited physical interaction of p65 with p300, nuclear cofactor of NF-κB. Intracellular levels of cAMP increased by AT. These results suggest that AT inhibits endothelial cell activation by, at least in some part, inhibiting physical interaction of NF-κB with cAMP/p300 by increasing in intracellular levels of cAMP in endothelial cells.
Achieving guideline-recommended low-density lipoprotein cholesterol (LDL-C) targets remains a significant challenge in clinical practice. This review assesses the barriers to reaching LDL-C goals and ...explores the potential solutions to these issues. When aiming for the recommended LDL-C goal, strategies like "lower is better" and "strike early and strong" should be used. The evidence supports the safety and efficacy of intensive lipid-lowering therapy post-acute coronary syndrome (ACS), leading to improved long-term cardiovascular health and atherosclerotic plaque stabilization. Despite the availability of effective lipid-lowering therapies, such as high-intensity statins, ezetimibe, the combination of both, bempedoic acid, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, a substantial proportion of patients do not meet their LDL-C targets. Contributing factors include systemic healthcare barriers, healthcare provider inertia, patient non-adherence, and statin intolerance. Statin intolerance, often rather statin reluctance, is a notable obstacle due to perceived or expected side effects, which can lead to discontinuation of therapy. In conclusion, while there are obstacles to achieving optimal LDL-C levels post-ACS, these can be overcome with a combination of patient-centric approaches, clinical vigilance, and the judicious use of available therapies. The safety and necessity of reaching lower LDL-C goals to improve outcomes in patients post-ACS are well-supported by current evidence.
Hyperglycemia significantly contributes to complications in patients with diabetes mellitus. While lifestyle interventions remain cornerstones of disease prevention and treatment, most patients with ...type 2 diabetes will eventually require pharmacotherapy for glycemic control. The definition of individual targets regarding optimal therapeutic efficacy and safety as well as cardiovascular effects is of great importance. In this guideline we present the most current evidence-based best clinical practice data for healthcare professionals.
Zusammenfassung
Die Hyperglykämie ist wesentlich an der Entstehung der Spätkomplikationen bei an Diabetes mellitus Typ 2 erkrankten Patienten/Patientinnen beteiligt. Während Lebensstilmaßnahmen die ...Eckpfeiler jeder Diabetestherapie bleiben, benötigen im Verlauf die meisten Patienten/Patientinnen mit Typ 2 Diabetes eine medikamentöse Therapie. Bei der Definition individueller Behandlungsziele stellen die Therapiesicherheit, die Effektivität sowie substanzspezifische, kardiovaskuläre Effekte der Therapie die wichtigsten Faktoren dar. In dieser Leitlinie haben wir die rezenten evidenzbasierten Daten für die klinische Praxis zusammengestellt.
Die Hyperglykämie ist wesentlich an der Entstehung der Spätkomplikationen bei an Diabetes mellitus Typ 2 erkrankten Patienten/Patientinnen beteiligt. Während Lebensstilmaßnahmen die Eckpfeiler jeder ...Diabetestherapie bleiben, benötigen im Verlauf die meisten Patienten/Patientinnen mit Typ 2 Diabetes eine medikamentöse Therapie. Bei der Definition individueller Behandlungsziele stellen die Therapiesicherheit, die Effektivität sowie substanzspezifische, kardiovaskuläre Effekte der Therapie die wichtigsten Faktoren dar. In dieser Leitlinie haben wir die rezenten evidenzbasierten Daten für die klinische Praxis zusammengestellt.
PDF
