Vitamin E Reduces Monocyte Tissue Factor Expression in Cirrhotic Patients

Integrative analysis identifies oxidative stress biomarkers in non-alcoholic fatty liver disease via machine learning and weighted gene co-expression network analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease globally, with the potential to progress to non-alcoholic steatohepatitis (NASH), cirrhosis, and even hepatocellular carcinoma. Given the absence of effective treatments to halt its progression, novel molecular approaches to the NAFLD diagnosis and treatment are of paramount importance.

Methods

Firstly, we downloaded oxidative stress-related genes from the GeneCards database and retrieved NAFLD-related datasets from the GEO database. Using the Limma R package and WGCNA, we identified differentially expressed genes closely associated with NAFLD. In our study, we identified 31 intersection genes by analyzing the intersection among oxidative stress-related genes, NAFLD-related genes, and genes closely associated with NAFLD as identified through Weighted Gene Co-expression Network Analysis (WGCNA). In a study of 31 intersection genes between NAFLD and Oxidative Stress (OS), we identified three hub genes using three machine learning algorithms: Least Absolute Shrinkage and Selection Operator (LASSO) regression, Support Vector Machine - Recursive Feature Elimination (SVM-RFE), and RandomForest. Subsequently, a nomogram was utilized to predict the incidence of NAFLD. The CIBERSORT algorithm was employed for immune infiltration analysis, single sample Gene Set Enrichment Analysis (ssGSEA) for functional enrichment analysis, and Protein-Protein Interaction (PPI) networks to explore the relationships between the three hub genes and other intersecting genes of NAFLD and OS. The distribution of these three hub genes across six cell clusters was determined using single-cell RNA sequencing. Finally, utilizing relevant data from the Attie Lab Diabetes Database, and liver tissues from NASH mouse model, Western Blot (WB) and Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) assays were conducted, this further validated the significant roles of CDKN1B and TFAM in NAFLD.

Results

In the course of this research, we identified 31 genes with a strong association with oxidative stress in NAFLD. Subsequent machine learning analysis and external validation pinpointed two genes: CDKN1B and TFAM, as demonstrating the closest correlation to oxidative stress in NAFLD.

Conclusion

This investigation found two hub genes that hold potential as novel targets for the diagnosis and treatment of NAFLD, thereby offering innovative perspectives for its clinical management.

Gut-derived low-grade endotoxaemia, atherothrombosis and cardiovascular disease

Systemic inflammation has been suggested to have a pivotal role in atherothrombosis, but the factors that trigger systemic inflammation have not been fully elucidated. Lipopolysaccharide (LPS) is a component of the membrane of Gram-negative bacteria present in the gut that can translocate into the systemic circulation, causing non-septic, low-grade endotoxaemia. Gut dysbiosis is a major determinant of low-grade endotoxaemia via dysfunction of the intestinal barrier scaffold, which is a prerequisite for LPS translocation into the systemic circulation. Experimental studies have demonstrated that LPS is present in atherosclerotic arteries but not in normal arteries. In atherosclerotic plaques, LPS promotes a pro-inflammatory status that can lead to plaque instability and thrombus formation. Low-grade endotoxaemia affects several cell types, including leukocytes, platelets and endothelial cells, leading to inflammation and clot formation. Low-grade endotoxaemia has been described in patients at risk of or with overt cardiovascular disease, in whom low-grade endotoxaemia was associated with atherosclerotic burden and its clinical sequelae. In this Review, we describe the mechanisms favouring the development of low-grade endotoxaemia, focusing on gut dysbiosis and changes in gut permeability; the plausible biological mechanisms linking low-grade endotoxaemia and atherothrombosis; the clinical studies suggesting that low-grade endotoxaemia is a risk factor for cardiovascular events; and the potential therapeutic tools to improve gut permeability and eventually eliminate low-grade endotoxaemia.

Interventional study with vitamin E in cardiovascular disease and meta-analysis

Cardiovascular disease (CVD) is one of the major causes of morbidity and mortality and atherosclerosis is the common root to most of the CVD. Oxidative stress is one of the most important factors driving atherosclerosis and its complications. Thus, strategies for the prevention and treatment of cardiovascular events had oxidative changes as a potential target. Natural vitamin E consists of a family of eight different compounds, four tocopherols and four tocotrienols. All tocopherols and tocotrienols are potent antioxidants with lipoperoxyl radical-scavenging activities. In addition, α-tocopherol possesses also anti-inflammatory as well as anti-atherothrombotic effects by modulating platelet and clotting system. Experimental and in vitro studies described molecular and cellular signalling pathways regulated by vitamin E antithrombotic and antioxidant properties. While observational studies demonstrated an inverse association between vitamin E serum levels and CVD, interventional trials with vitamin supplements provided negative results. This review focus on the impact of vitamin E in the atherothrombotic process and describes the results of experimental and clinical studies with the caveats related to the interventional trials with vitamin E to prevent CVD.

Anticoagulation in patients with advanced liver disease: an open issue

Liver disease has been long considered as a risk factor for bleeding for the presence of prolongation of global tests of clotting activation and low platelet count. For this reason, the use of anticoagulants in patients with liver disease and an indication to anticoagulation, such as atrial fibrillation of venous thrombosis, has been poorly considered. Furthermore, recent studies underscored the fact that patients with chronic liver disease may experience thrombosis in portal as well as systemic circulation and treatment with anticoagulants should be considered. The introduction of direct oral anticoagulants has increased therapeutic options for thromboprophylaxis; however, evidence on their safety and efficacy in specific populations, such as patients with liver disease, is still scarce and needs further investigation. Thus, atrial fibrillation patients with coexistent liver disease have been excluded from clinical trials with direct oral anticoagulants. Here, we provide an overview on mechanisms of thrombosis in patients with advanced chronic liver disease and a summary of evidence on the use of oral anticoagulants in patients with liver disease and portal vein thrombosis or atrial fibrillation.

Nutrition, Thrombosis, and Cardiovascular Disease

Previous studies reported an inverse association between healthy dietary patterns (such as Mediterranean diet) and the incidence of cardiovascular events. As the mechanism accounting for cardiovascular disease is prevalently due to the atherothrombosis, where a pivotal role is played by platelet activation, it would be arguable that diets with protective effects against cardiovascular disease exert an anti-atherothrombotic effect via inhibition of platelet activation. There are several and sparse typologies of studies, which investigated if single nutrients by diets recognized as having cardiovascular protection may exert an antithrombotic effect. The most investigated nutrients are key components of the Mediterranean diets such as fruits and vegetables, fish, olive oil, and wine; other diets with protective effects include nuts and cocoa. Here we summarize experimental and human interventional studies which investigated the antithrombotic effects of such nutrients in experimental models of thrombosis or analyzed biomarkers of clotting, platelet, and fibrinolysis activation in human; furthermore in vitro studies explored the underlying mechanism at level of several cell lines such as platelets or endothelial cells. In this context, we analyzed if nutrients affect simultaneously or separately clotting, platelet, and fibrinolysis pathways giving special attention to the relationship between oxidative stress and thrombosis as most nutrients are believed to possess antioxidant properties.

Hepatocyte tissue factor contributes to the hypercoagulable state in a mouse model of chronic liver injury

BACKGROUND & AIMS

Patients with chronic liver disease and cirrhosis have a dysregulated coagulation system and are prone to thrombosis. The basis for this hypercoagulable state is not completely understood. Tissue factor (TF) is the primary initiator of coagulation in vivo. Patients with cirrhosis have increased TF activity in white blood cells and circulating microparticles. The aim of our study was to determine the contribution of TF to the hypercoagulable state in a mouse model of chronic liver injury.

METHODS

We measured levels of TF activity in the liver, white blood cells and circulating microparticles, and a marker of activation of coagulation (thrombin-antithrombin complexes (TATc)) in the plasma of mice subjected to bile duct ligation for 12days. We used wild-type mice, mice with a global TF deficiency (low TF mice), and mice deficient for TF in either myeloid cells (TF(flox/flox),LysMCre mice) or in hepatocytes (TF(flox/flox),AlbCre).

RESULTS

Wild-type mice with liver injury had increased levels of white blood cell, microparticle TF activity and TATc compared to sham mice. Low TF mice and mice lacking TF in hepatocytes had reduced levels of TF in the liver and in microparticles and exhibited reduced activation of coagulation without a change in liver fibrosis. In contrast, mice lacking TF in myeloid cells had reduced white blood cell TF but no change in microparticle TF activity or TATc.

CONCLUSIONS

Hepatocyte TF activates coagulation in a mouse model of chronic liver injury. TF may contribute to the hypercoagulable state associated with chronic liver diseases in patients.

Vitamin E serum levels and bleeding risk in patients receiving oral anticoagulant therapy: a retrospective cohort study

Background

Hemorrhagic risk assessment is a crucial issue in patients with nonvalvular atrial fibrillation (NVAF) who are receiving oral anticoagulant therapy (OAT). Our aim was to analyze the relationship between vitamin E, which possesses anticoagulant properties, and bleeding events in NVAF patients.

Methods and Results

In this retrospective observational study we analyzed baseline serum cholesterol‐adjusted vitamin E (vit E/chol) levels in 566 consecutive patients (59% males, mean age 73.6 years) receiving OAT followed up for a mean time of 22 months. Mean time in therapeutic INR range (TTR) was 64%. The overall incidence rate of any bleeding event was 9.2/100 person‐years. Compared to patients who did not bleed, those who experienced bleeding events (n=92, 73 minor and 15 major bleedings and 4 cerebral hemorrhages according to International Society on Thrombosis and Haemostasis [ISTH] ) classification) showed a significant difference for history of coronary heart disease (P=0.039), HAS‐BLED score (P=0.002), and vit E/chol levels (P<0.001). Higher vit E/chol serum levels were found in patients who bled compared to those who did not (5.27±1.93 versus 4.48±1.97 μmol/cholesterol; P<0.001), with a progressive increase from minor (5.16±1.91 μmol/mmol cholesterol, P=0.006) to major bleedings (5.72±2.0 μmol/mmol cholesterol, P=0.008). A Cox proportional hazard model demonstrated that serum vit E/chol quartiles (global P=0.0189) and HAS‐BLED scores (P=0.005) predicted bleeding events.

Conclusions

In a NVAF population being treated with warfarin, serum vitamin E predicted hemorrhagic events. Further study is necessary to see if the relationship between serum levels of vitamin E and bleeding is still maintained with the use of new anticoagulants.

Clinical Trial Registration

URL: ClinicalTrials.gov. Unique identifier NCT01882114.

Vitamin E supplementation increases polyunsaturated fatty acids of RBC membrane in HCV-infected patients

OBJECTIVE

We investigated the effects of vitamin E supplementation on the fatty acid composition of red blood cell membrane phospholipids and on the clinical observations in patients with hepatitis C virus.

METHOD

Eight patients and control subjects were administered 500 mg/d of d-alpha-tocopherol for 12 wk. The alpha-tocopherol and fatty acid composition of phospholipids in red blood cells were analyzed before, at 4, 8, and 12 wk, and after 4 wk of washout of vitamin E administration.

RESULTS

The alpha-tocopherol concentration in red blood cells increased 2.37-fold of the basal level during vitamin E supplementation. Serum alanine aminotransferase levels increased in five of eight patients with vitamin E supplementation. The arachidonic acid level, docosahexaenoic acid level, and ratio of polyunsaturated to saturated fatty acid in red blood cell membrane phospholipids, which were significantly lower in the patients than in the control subjects, were elevated at 8 and 12 wk after vitamin E supplementation. The improvement in fatty acid composition was observed particularly in the patients who responded to the vitamin E therapy.

CONCLUSIONS

Vitamin E therapy for the prevention of disease progression in patients with hepatitis C virus may be effective.

Arachidonic acid in mononuclear cells and its clinical significance in HCV cirrhotic patients

OBJECTIVES

An abnormal fatty acid pattern in patients with advanced liver cirrhosis (LC) has been reported in plasma phospholipids and some other tissues. To elucidate the significance of arachidonic acid deficiency on the clinical pathophysiology of LC and hepatocellular carcinoma (HCC), we analyzed the fatty acid compositions of mononuclear cell phospholipids, plasma alpha-tocopherol, and thiobarbituric acid-reactive substances and serum tumor necrosis factor-alpha (TNF-alpha) in cirrhotic patients infected with the hepatitis C virus with and without HCC.

METHODS

Twelve cirrhotic patients without HCC (LC patients) and 11 with HCC (HCC patients) were enrolled. Fatty acids were analyzed with gas chromatography. alpha-Tocopherol and TNF-alpha were analyzed by high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. Statistical analysis was performed by using the unpaired t test with Welch's correction and Spearman's rank-correlation analysis.

RESULTS

Significantly low levels of linoleic, dihomo-gamma-linolenic, arachidonic, and eicosapentaenoic acids from mononuclear cell phospholipids were observed in LC and HCC patients compared with control subjects. Plasma alpha-tocopherol was lower and thiobarbituric acid-reactive substances were higher in HCC patients than in controls. Arachidonic acid molar percentage in mononuclear cell phospholipids correlated significantly with lymphocyte count (r = 0.460, P < 0.05) in the cirrhotic patients and with lymphocyte (r = 0.680, P < 0.01) and platelet (r = 0.763, P < 0.01) counts in all subjects.

CONCLUSIONS

These results suggested that arachidonic acid in mononuclear cells may have an important role in the pathophysiology of hepatitis C virus associated with cirrhosis and that nutritional management preventing arachidonic acid deficiency may have some beneficial effects on the progression of LC.

Habitual food intake and polyunsaturated fatty acid deficiency in liver cirrhosis

OBJECTIVE

We compared the habitual food intake and plasma fatty acid composition in cirrhotic patients living in two different regions in Japan, Okayama and Toyama, and evaluated the effects of dietary polyunsaturated fatty acid and alpha-tocopherol intake on serum alanine aminotransferase (ALT) activity.

METHOD

A quantitative food-frequency questionnaire method was used.

RESULTS

The significantly higher intake of fish in the patients living in Toyama resulted in higher plasma levels of docosahexaenoic acid and lower levels of arachidonic acid. Serum ALT activity correlated negatively with plasma arachidonic acid (r = -0.456, P < 0.05) and alpha-tocopherol (r = -0.505, P < 0.05) levels. Dietary intakes of vitamin E and polyunsaturated fatty acids (mg/g) correlated negatively with serum ALT (r = -0.377, P < 0.05). Dietary intake of linoleic acid and the ratio of polyunsaturated to saturated fatty acid in dietary fat correlated significantly with serum ALT (r = 0.604, P < 0.01, and r = 0.622, P < 0.01, respectively). The amount of vegetable intake correlated with intake of vitamin E and polyunsaturated fatty acid (r = 0.527, P < 0.02).

CONCLUSIONS

These findings suggest that habitual food intake affects the plasma fatty acid profile and that elevated serum ALT may be related to arachidonic acid deficiency and vulnerability to lipid peroxidation in cirrhotic patients with hepatitis B and C viruses.

[Isoprostanes: new markers of oxidative stress. Fundamental and clinical aspects]

A novel family of prostaglandin F2 isomers, called F2-isoprostanes, produced in large quantities in vivo by a free radical peroxidation of arachidonic acid, has recently been described. The quantification of the two major isoforms (isoprostaglandin F2alpha type-III and VI) in biological fluids and tissues as markers of lipid peroxidation appears to be an important advance in our ability to explore the role of free radicals in the pathogenesis of human disease. In addition, F2-isoporstanes quantification seems promising as intermediate endpoints for clinical studies of antioxidant therapies.