Tissue factor and cardiomyocytes

Understanding One Half of the Sex Difference Equation: The Modulatory Effects of Testosterone on Diabetic Cardiomyopathy

Diabetes is a prevalent disease, primarily characterized by high blood sugar (hyperglycemia). Significantly higher rates of myocardial dysfunction have been noted in individuals with diabetes, even in those without coronary artery disease or high blood pressure (hypertension). Numerous molecular mechanisms have been identified through which diabetes contributes to the pathology of diabetic cardiomyopathy, which presents as cardiac hypertrophy and fibrosis. At the cellular level, oxidative stress and inflammation in cardiomyocytes are triggered by hyperglycemia. Although males are generally more likely to develop cardiovascular disease than females, diabetic males are less likely to develop diabetic cardiomyopathy than are diabetic females. One reason for these differences may be the higher levels of serum testosterone in males compared with females. Although testosterone appears to protect against cardiomyocyte oxidative stress and exacerbate hypertrophy, its role in inflammation and fibrosis is much less clear. Additional preclinical and clinical studies will be required to delineate testosterone's effect on the diabetic heart.

Role of toll-like receptor-mediated pyroptosis in sepsis-induced cardiomyopathy

Sepsis, a life-threatening dysregulated status of the host response to infection, can cause multiorgan dysfunction and mortality. Sepsis places a heavy burden on the cardiovascular system due to the pathological imbalance of hyperinflammation and immune suppression. Myocardial injury and cardiac dysfunction caused by the aberrant host responses to pathogens can lead to cardiomyopathy, one of the most critical complications of sepsis. However, many questions about the specific mechanisms and characteristics of this complication remain to be answered. The causes of sepsis-induced cardiac dysfunction include abnormal cardiac perfusion, myocardial inhibitory substances, autonomic dysfunction, mitochondrial dysfunction, and calcium homeostasis dysregulation. The fight between the host and pathogens acts as the trigger for sepsis-induced cardiomyopathy. Pyroptosis, a form of programmed cell death, plays a critical role in the progress of sepsis. Toll-like receptors (TLRs) act as pattern recognition receptors and participate in innate immune pathways that recognize damage-associated molecular patterns as well as pathogen-associated molecular patterns to mediate pyroptosis. Notably, pyroptosis is tightly associated with cardiac dysfunction in sepsis and septic shock. In line with these observations, induction of TLR-mediated pyroptosis may be a promising therapeutic approach to treat sepsis-induced cardiomyopathy. This review focuses on the potential roles of TLR-mediated pyroptosis in sepsis-induced cardiomyopathy, to shed light on this promising therapeutic approach, thus helping to prevent and control septic shock caused by cardiovascular disorders and improve the prognosis of sepsis patients.

Depression, anxiety, and vital exhaustion are associated with pro-coagulant markers in depressed patients with coronary artery disease - A cross sectional and prospective secondary analysis of the SPIRR-CAD trial

INTRODUCTION

A hyper-coagulant state is a biological mechanism that triggers cardiac events in patients with coronary artery disease (CAD). Depressive symptoms and anxiety predict an unfavourable course of CAD. The SPIRR-CAD-RCT examined the effects of a psychological intervention and provided the opportunity to explore cross-sectional associations between indices of psychological strain and coagulation parameters, as well as prospective changes in depression scores and coagulation parameters.

METHODS

In this secondary analysis, we investigated 253 CAD patients (194 male; age m 58.9, SD 8.3 yrs.) with mild to moderate depression (≥8 on the HADS-D) at baseline and at follow-up 18 months later: TF, fibrinogen, D-dimer, VWF, FVII and PAI-1 and the course of depression (HAM-D), vital exhaustion (VE) and anxiety scores (HADS-A) were examined by ANOVA in the total and younger age groups (≤ 60).

RESULTS

HAM-D at baseline was correlated with TF (corr. R² = 0.27; F = 9.31, p = 0.001). HADS anxiety was associated with fibrinogen (corr. R².20; F = 7.27, p = 0.001). There was no detectable therapeutic effect on coagulation. Fibrinogen and VWF decreased within 18 months (time effect; p = 0.02; p = 0.04), as did HADS-D in both treatment groups (p < 0.001). Fibrinogen decreased more in patients ≤60 years with high VE compared to low VE (interaction time x group, p = 0.01).

CONCLUSIONS

This is the first study to show an association between TF and depression. Coagulation parameters as potential mediators of CAD progression correlated cross-sectionally with depression and anxiety and prospectively with VE. Further studies should replicate these correlations in depressed and non-depressed CAD patients.

ISRCTN

76240576; clinicaltrials.gov.

The pleiotropic effects of antithrombotic drugs in the metabolic-cardiovascular-neurodegenerative disease continuum: impact beyond reduced clotting

Antithrombotic drugs are widely used for primary and secondary prevention, as well as treatment of many cardiovascular disorders. Over the past few decades, major advances in the pharmacology of these agents have been made with the introduction of new drug classes as novel therapeutic options. Accumulating evidence indicates that the beneficial outcomes of some of these antithrombotic agents are not solely related to their ability to reduce thrombosis. Here, we review the evidence supporting established and potential pleiotropic effects of four novel classes of antithrombotic drugs, adenosine diphosphate (ADP) P2Y12-receptor antagonists, Glycoprotein IIb/IIIa receptor Inhibitors, and Direct Oral Anticoagulants (DOACs), which include Direct Factor Xa (FXa) and Direct Thrombin Inhibitors. Specifically, we discuss the molecular evidence supporting such pleiotropic effects in the context of cardiovascular disease (CVD) including endothelial dysfunction (ED), atherosclerosis, cardiac injury, stroke, and arrhythmia. Importantly, we highlight the role of DOACs in mitigating metabolic dysfunction-associated cardiovascular derangements. We also postulate that DOACs modulate perivascular adipose tissue inflammation and thus, may reverse cardiovascular dysfunction early in the course of the metabolic syndrome. In this regard, we argue that some antithrombotic agents can reverse the neurovascular damage in Alzheimer's and Parkinson's brain and following traumatic brain injury (TBI). Overall, we attempt to provide an up-to-date comprehensive review of the less-recognized, beneficial molecular aspects of antithrombotic therapy beyond reduced thrombus formation. We also make a solid argument for the need of further mechanistic analysis of the pleiotropic effects of antithrombotic drugs in the future.

Tissue factor, protease activated receptors and pathologic heart remodelling

Tissue factor is the primary initiator of coagulation cascade and plays an essential role in haemostasis and thrombosis. In addition, tissue factor and coagulation proteases contribute to many cellular responses via activation of protease activated receptors. The heart is an organ with high levels of constitutive tissue factor expression. This review focuses on the role of tissue factor, coagulation proteases and protease activated receptors in heart haemostasis and the pathological heart remodelling associated with myocardial infarction, viral myocarditis and hypertension.

Role of protease-activated receptors for the innate immune response of the heart

Protease-activated receptors (PARs) are a family of G-protein-coupled receptors with a unique activation mechanism via cleavage by the serine proteases of the coagulation cascade, immune cell-released proteases, and proteases from pathogens. Pathogens, such as viruses and bacteria, cause myocarditis and heart failure and PAR1 was shown to positively regulate the anti-viral innate immune response via interferon β during virus-induced myocarditis. In contrast, PAR2 negatively regulated the innate immune response and inhibited the interferon β expression. Thus, PARs play a central role for the innate immune response in the heart.