Hypercoagulability in Patients with Non-Alcoholic Fatty Liver Disease (NAFLD): Causes and Consequences

Neutrophil extracellular traps (NETs) and fibrotic diseases

Fibrosis, a common cause and serious outcome of organ failure that can affect any organ, is responsible for up to 45% of all deaths in various clinical settings. Both preclinical models and clinical trials investigating various organ systems have shown that fibrosis is a highly dynamic process. Although many studies have sought to gain understanding of the mechanism of fibrosis progression, their findings have been mixed. In recent years, increasing evidence indicates that neutrophil extracellular traps (NETs) are involved in many inflammatory and autoimmune disorders and participate in the regulation of fibrotic processes in various organs and systems. In this review, we summarize the current understanding of the role of NETs in fibrosis development and progression and their possibility as therapeutic targets.

Endotoxemia and Platelets: 2 Players of Intrahepatic Microthrombosis in NAFLD

Gut dysbiosis-related intestinal barrier dysfunction with increased translocation of bacterial products such as lipopolysaccharide (LPS) into systemic circulation is emerging as pathogenic factor of nonalcoholic fatty liver disease (NAFLD). Experimental and clinical studies suggested a potential role of LPS as a trigger eliciting in situ liver inflammation upon interaction with its receptor toll-like receptor 4. Also, LPS has been reported to prime platelets to respond to the common agonists indicating that it behaves as a prothrombotic molecule. Of note, recent studies suggested platelet-related intrahepatic thrombosis triggered by LPS as a mechanism implicated in the process of liver inflammation. This review describes: 1) the impact of gut barrier dysfunction and endotoxemia in the process of NAFLD; 2) the relationship between endotoxemia and platelet activation in NAFLD; 3) clinical evidence for the use of antiplatelet drugs in NAFLD/nonalcoholic steatohepatitis patients; and 4) the potential therapeutic approach to modulate endotoxemia and eventually platelet activation.

Regulation of Benzo[a]pyrene-Induced Hepatic Lipid Accumulation through CYP1B1-Induced mTOR-Mediated Lipophagy

Metabolic dysfunction-associated steatotic liver disease (MASLD) is caused by lipid accumulation within the liver. The pathogenesis underlying its development is poorly understood. Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon and a group 1 carcinogen. The aryl hydrocarbon receptor activation by B[a]P induces cytochrome P450 (CYP) enzymes, contributing to hepatic lipid accumulation. However, the molecular mechanism through which the B[a]P-mediated induction of CYP enzymes causes hepatic lipid accumulation is unknown. This research was conducted to elucidate the role of CYP1B1 in regulating B[a]P-induced lipid accumulation within hepatocytes. B[a]P increased hepatic lipid accumulation, which was mitigated by CYP1B1 knockdown. An increase in the mammalian target of rapamycin (mTOR) by B[a]P was specifically reduced by CYP1B1 knockdown. The reduction of mTOR increased the expression of autophagic flux-related genes and promoted phagolysosome formation. Both the expression and translocation of TFE3, a central regulator of lipophagy, were induced, along with the expression of lipophagy-related genes. Conversely, enhanced mTOR activity reduced TFE3 expression and translocation, which reduced the expression of lipophagy-related genes, diminished phagolysosome production, and increased lipid accumulation. Our results indicate that B[a]P-induced hepatic lipid accumulation is caused by CYP1B1-induced mTOR and the reduction of lipophagy, thereby introducing novel targets and mechanisms to provide insights for understanding B[a]P-induced MASLD.

Role of Perturbated Hemostasis in MASLD and Its Correlation with Adipokines

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise, making it one of the most prevalent chronic liver disorders. MASLD encompasses a range of liver pathologies, from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH) with inflammation, hepatocyte damage, and fibrosis. Interestingly, the liver exhibits close intercommunication with fatty tissue. In fact, adipose tissue could contribute to the etiology and advancement of MASLD, acting as an endocrine organ that releases several hormones and cytokines, with the adipokines assuming a pivotal role. The levels of adipokines in the blood are altered in people with MASLD, and recent research has shed light on the crucial role played by adipokines in regulating energy expenditure, inflammation, and fibrosis in MASLD. However, MASLD disease is a multifaceted condition that affects various aspects of health beyond liver function, including its impact on hemostasis. The alterations in coagulation mechanisms and endothelial and platelet functions may play a role in the increased vulnerability and severity of MASLD. Therefore, more attention is being given to imbalanced adipokines as causative agents in causing disturbances in hemostasis in MASLD. Metabolic inflammation and hepatic injury are fundamental components of MASLD, and the interrelation between these biological components and the hemostasis pathway is delineated by reciprocal influences, as well as the induction of alterations. Adipokines have the potential to serve as the shared elements within this complex interrelationship. The objective of this review is to thoroughly examine the existing scientific knowledge on the impairment of hemostasis in MASLD and its connection with adipokines, with the aim of enhancing our comprehension of the disease.

The prothrombotic tendency of metabolic-associated fatty liver disease

Our understanding of the function of the liver has evolved over the centuries. Early theories proposing that the liver could be used to divine the future have been superseded by our current knowledge of the importance of the liver in processes such as digestion and detoxification. Similarly, although liver disease was previously associated with only an increased risk of bleeding, there is now a substantial body of evidence demonstrating an increased thrombotic potential in patients with this disease. Metabolic-associated fatty liver disease (MAFLD) is increasing in frequency and is likely to overtake alcoholic liver disease as the primary indication for liver transplant in the future. In this review, we discuss the evidence linking liver disease, and MAFLD in particular, with arterial and venous thromboembolic disease. We review the safety and efficacy of anticoagulation in advanced liver disease and consider whether antithrombotic agents could slow or halt the progression of fibrosis in MAFLD.

NAFLD: An Emerging Causal Factor for Cardiovascular Disease

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide that poses a significant threat to human health. Cardiovascular disease (CVD) is the leading cause of mortality in NAFLD patients. NAFLD and CVD share risk factors such as obesity, insulin resistance, and type 2 diabetes. However, whether NAFLD is a causal risk factor for CVD remains a matter of debate. This review summarizes the evidence from prospective clinical and Mendelian randomization studies that underscore the potential causal relationship between NAFLD and CVD. The mechanisms of NAFLD contributing to the development of CVD and the necessity of addressing CVD risk while managing NAFLD in clinical practice are also discussed.

Association of nonalcoholic fatty liver disease and venous thromboembolic disease in healthy adults in Korea: a nationwide study

Nonalcoholic fatty liver disease (NAFLD) can lead to a prothrombotic state, which significantly burdens public healthcare systems. This study investigated the relationship between NAFLD and the incidence of venous thromboembolism (VTE) in Korea using National Health Insurance Service-National Sample Cohort 2.0 data. A population-based retrospective cohort analysis was conducted on 472,212 healthy individuals who underwent national health check-ups in Korea from 2009 to 2014. NAFLD was defined using the fatty liver index (FLI). Multivariate Cox proportional hazards regression models were used to analyze the association between FLI and VTE. Individuals were categorized into four quartiles according to FLI values (first quartile [Q1], 0-5.7; second quartile [Q2], 5.8-15.3; third quartile [Q3], 15.4-37.2; and fourth quartile [Q4], > 37.2). The incidence of VTE tended to increase with increasing FLI values (Q1, 598 [0.5%]; Q2, 1,033 [0.9%]; Q3, 1,443 [1.2%]; and Q4, 1,425 [1.2%]). In the age- and sex-adjusted multivariate model, the hazard ratio (HR) (95% confidence interval [CI]) was 1.47 (1.33‒1.62) for Q4 compared with Q1. After adjusting for clinical variables with P < 0.1 in the univariate analyses, the HR (95% CI) was 1.45 (1.30‒1.62) for Q4 compared with Q1. FLI was related to VTE risk, as confirmed after adjusting for other risk factors.

Association between the platelet/high-density lipoprotein cholesterol ratio and nonalcoholic fatty liver disease: results from NHANES 2017-2020

The platelet/high-density lipoprotein cholesterol ratio (PHR) is a novel inflammatory and hypercoagulability marker that represents the severity of metabolic syndrome. Liver metabolic syndrome is manifested by nonalcoholic fatty liver disease (NAFLD), which is associated with inflammation and hypercoagulability. This cross-sectional investigation aimed to identify the relationship between PHR and NAFLD. Participants in the National Health and Nutrition Examination Survey (NHANES) 2017-2020 were evaluated for hepatic steatosis and fibrosis using vibration-controlled transient elastography. The PHR was calculated as the ratio of platelets to high-density lipoprotein cholesterol. Increased PHR was associated with an increased incidence of NAFLD and hepatic fibrosis. Compared with patients in the first PHR quartile, after adjustment for clinical variables, the corresponding odds ratio (OR) for NAFLD in the fourth quartile was 2.36 (95% CI, 1.76 to 3.18) (p < 0.05); however, the OR for hepatic fibrosis was not statistically significant (p > 0.05). Furthermore, restricted cubic spline analyses showed an S-shaped association between PHR and NAFLD and an L-shaped relationship between PHR and hepatic fibrosis. The results support the effectiveness of PHR as a marker for NAFLD and hepatic fibrosis. Therefore, interventions to improve the PHR may be of benefit in reducing the incidence of both hepatic steatosis and fibrosis.

Emerging Role of Neutrophil Extracellular Traps in Gastrointestinal Tumors: A Narrative Review

Neutrophil extracellular traps (NETs) are extracellular fibrous networks consisting of depolymerized chromatin DNA skeletons with a variety of antimicrobial proteins. They are secreted by activated neutrophils and play key roles in host defense and immune responses. Gastrointestinal (GI) malignancies are globally known for their high mortality and morbidity. Increasing research suggests that NETs contribute to the progression and metastasis of digestive tract tumors, among them gastric, colon, liver, and pancreatic cancers. This article explores the formation of NETs and reviews the role that NETs play in the gastrointestinal oncologic microenvironment, tumor proliferation and metastasis, tumor-related thrombosis, and surgical stress. At the same time, we analyze the qualitative and quantitative detection methods of NETs in recent years and found that NETs are specific markers of coronavirus disease 2019 (COVID-19). Then, we explore the possibility of NET inhibitors for the treatment of digestive tract tumor diseases to provide a new, efficient, and safe solution for the future therapy of gastrointestinal tumors.

Protective effect of traditional Chinese medicine on non-alcoholic fatty liver disease and liver cancer by targeting ferroptosis

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease with high incidence and is closely related to metabolic syndrome. If not controlled, it may eventually become hepatocellular carcinoma (HCC). Ferroptosis, a non-apoptotic form of programmed cell death (PCD), is closely related to NAFLD and HCC, and the mechanisms of action involved are more complex. Some studies have demonstrated that many drugs inhibit ferroptosis and protect liver steatosis or carcinogenesis. The role of Traditional Chinese Medicine (TCM), especially herbs or herbal extracts, has received increasing attention. However, there are relatively few review articles on the regulation of NAFLD by TCM through ferroptosis pathway. Here, we summarize the TCM intervention mechanism and application affecting NAFLD/NAFLD-HCC via regulation of ferroptosis. This article focuses on the relationship between ferroptosis and NAFLD or NAFLD-HCC and the protective effect of TCM on both by targeting ferroptosis. It not only summarizes the mechanism of early prevention and treatment of NAFLD, but also provides reference ideas for the development of TCM for the treatment of metabolic diseases and liver diseases.

Association of non-alcoholic fatty liver disease with left ventricular changes in treatment-naive patients with uncomplicated hypertension

Background and aims

Cardiac structural and functional changes have been demonstrated in patients with non-alcoholic fatty liver disease (NAFLD). Because of the frequent association of NAFLD with hypertension, we aimed to examine the relationship of liver steatosis with left ventricular (LV) changes in patients with hypertension.

Materials and methods

In a cross-sectional study, we included 360 untreated, essential hypertensive patients who were free of major cardiovascular and renal complications. Liver steatosis was assessed by three different biochemical scores (NAFLD Liver Fat Score, LFS; Fatty Liver Index, FLI; Hepatic Steatosis Index, HSI). Echocardiography was performed with standard B-mode and tissue-Doppler imaging.

Results

LV hypertrophy was present in 19.4% and LV diastolic dysfunction in 49.2% of patients who had significantly higher body mass index (BMI), blood pressure (BP), and homeostatic model assessment (HOMA) index and higher frequency of the metabolic syndrome and liver steatosis that was defined by presence of 2 or more positive scores. LV mass index increased progressively across patients who had none, 1, or 2 or more liver steatosis scores, with associated progressive worsening of LV diastolic function. LV mass index was significantly and positively correlated with age, BMI, BP, HOMA-index, LFS, and HSI. Logistic regression analysis showed that age, BP, and liver steatosis scores independently predicted LV hypertrophy and diastolic dysfunction. Liver steatosis independently predicted LV dysfunction but not LV hypertrophy even after inclusion in analysis of the HOMA-index.

Conclusion

NAFLD is associated with LV hypertrophy and diastolic dysfunction in untreated patients with hypertension. In hypertension, NAFLD could contribute to LV diastolic dysfunction with mechanisms unrelated to insulin resistance.

Interplay between coagulation and determinants of liver disease in patients with metabolic dysfunction

Background & Aims

The aim of this study was to examine the determinants of the interplay between liver damage and the coagulation balance in individuals at risk of non-alcoholic fatty liver disease (NAFLD).

Methods

We considered 581 healthy participants with ≥3 metabolic alterations undergoing clinical and genomic evaluation, measurement of liver stiffness (LSM) and controlled attenuation parameter (CAP) by Fibroscan, Pro-C3, coagulation balance (von Willebrand factor [vWF], factor VIII/protein C ratio [F8/PC] as the main outcome, D-dimer as marker of coagulation/fibrinolysis activation).

Results

Liver fibrosis indices (both Fibrosis-4 [FIB-4] and liver stiffness measurement [LSM]), but not liver fat (CAP), were independently associated with higher F8/PC ratio (p <0.01), triggering D-dimer formation (p = 2E-21). In keeping with a causal role of liver damage in determining a procoagulant status, the main fatty liver inherited risk variant PNPLA3 p.I148M was independently associated with the F8/PC ratio (p = 0.048). Vice versa, the main determinant of the coagulation balance was ABO locus variation (p = 1E-16), through the impact on vWF (p = 8E-26). Both rs687289 ABO and factor V Leiden were independently associated with higher Pro-C3 (p <0.025), with the effect of ABO being mediated by the impact on vWF (p = 5E-10 for association with Pro-C3). Mendelian randomisation analysis was consistent with a causal association of procoagulant imbalance with heightened fibrogenesis (p = 0.001 at robust MR-Egger for Pro-C3), but not with fibrosis (for LSM; p = not significant).

Conclusions

In individuals with metabolic dysfunction, liver damage severity and possibly the PNPLA3 p.I148M variant were associated with procoagulant status. Vice versa, evaluation of inherited variants in ABO and other genes influencing coagulation was consistent with a causal role of procoagulant imbalance in activation of early stages of fibrogenesis.

Lay summary

In individuals with metabolic alterations at risk of metabolic fatty liver disease, there is a tendency toward heightened blood coagulation (clotting), but the cause and the impact on the progression of liver disease remain unclear. Here we show that liver damage severity and metabolic alterations, but not hepatic fat, are mainly responsible for heightened coagulation in patients with metabolic fatty liver disease. By using genetic approaches, we showed that hepatic inflammation due to lipotoxicity may favour heightened coagulation, which in turn can trigger liver fibrosis, igniting a vicious cycle that leads to progressive liver disease.

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There is a complex interplay between liver damage and the coagulation balance in individuals at risk of non-alcoholic fatty liver disease.

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Non-invasive indices and genetic determinants of liver damage, but not fat, were associated with a procoagulant imbalance.

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Vice versa, genetic predisposition to hypercoagulability was associated with fibrogenesis.

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In individuals with metabolic dysfunction, liver damage appears to promote coagulation, which in turn can activate fibrogenesis.