Association between CD14-159C>T polymorphisms and the risk for alcoholic liver disease: a meta-analysis

Pattern recognition receptor CD14 gene polymorphisms in alcohol use disorder patients and its Influence on liver disease susceptibility

Background

Alcohol use disorders (AUDs) leading to liver disease is major concern over other spectrum of disorder. Excessive alcohol consumption resulting in leaky gut syndrome is attributed to alcohol-induced liver injury through portal translocation of bacterial endotoxin. Susceptibility to alcoholic liver disease (ALD) in AUD patients could be dependent upon genes responsible for inflammation and alcohol metabolism. The pattern recognition receptor CD14 gene is a major player in endotoxin-mediated inflammation and susceptibility to ALD. This study investigated the genetic association of CD14 polymorphisms and other mechanisms relevant to altered inflammatory responses leading to ALD.

Methods

Patients with alcohol use disorder with ALD (n = 128) and without liver disease (ALC, n = 184) and controls without alcohol use disorder (NALC, n = 152) from North India were enrolled. The CD4 gene polymorphisms in the North Indian population were evaluated by RFLP and sequencing. Secretory CD14 (sCD14), LBP, TLR4, MD2, TNFα, IL1b, IFNγ, IL6, IL10, and IL4 levels in serum were measured by ELISA among groups. The influence of polymorphisms on CD14 gene promoter activity and circulatory bacterial DNA level was determined.

Results

The CD14 gene promoter and exonic region SNPs were found to be monomorphic, except for SNP rs2569190 for the North Indian population. The genetic association of SNP rs2569190(C/T) with the risk of developing ALD was found significant for TT genotype [OR_TT, 95% CI = 2.19, 1.16–4.13 for ALD vs. ALC and OR, 2.09, 1.18–3.72 for ALD vs. NALC]. An increased sCD14 level was observed in AUD patients compared to NALC control. Increased levels of LBP, TLR4, TNFα, IL1β, IFNγ, and IL6 and reduced levels of MD2, IL10, and IL4 were observed among the ALD patients compared to the other two control groups. Elevated levels of pro-inflammatory and reduced levels of anti-inflammatory cytokines were observed in the risk genotype TT groups of ALD patients and the ALC group compared to NALC. Promoter activity was observed in the intronic region flanking SNPs and risk genotype can influence reporter activity, indicating CD14 gene expression.

Conclusion

Enhanced CD14 expression associated with inflammatory responses increases susceptibility to ALD in the TT genotype of AUD patients.

A two gene-based risk score predicts alcoholic cirrhosis development in males with at-risk alcohol consumption

Background

Alcoholic cirrhosis represents 1% of all cause-of-deaths worldwide. Its incidence is higher in males and results from the combination of environmental and genetic factors. Among all the genetic determinants of alcoholic cirrhosis, the patatin-like phospholipase domain protein 3 (PNPLA3) rs738409 represents the most widely validated determinant. Recent cross-sectional studies on alcohol abusers identified transmembrane-6 superfamily member 2 (TM6SF2) rs58542926, membrane bound O-acyltransferase domain containing 7 (MBOAT7) rs641738, and cluster of differentiation 14 (CD14) rs2569190 as new genetic risk factors for alcoholic cirrhosis. We aimed to develop a gene-based risk score to predict the incidence of alcoholic cirrhosis in males with at-risk alcohol consumption.

Materials and methods

A total of 416 male at-risk alcohol drinkers were retrospectively examined. The association between alcoholic cirrhosis incidence and PNPLA3, CD14, TM6SF2, and MBOAT7 variants was tested. Age at onset of at-risk alcohol consumption, age, and body mass index (BMI) were included as covariates to determine the prediction score for alcoholic cirrhosis incidence by evaluating time-dependent receiver operating characteristic curves.

Results

We found that PNPLA3, CD14, and TM6SF2 were associated with alcoholic cirrhosis prevalence. PNPLA3 and CD14 were also associated with its incidence. The best predictive score formula was (age at onset of at-risk alcohol consumption × 0.1) + (number of CD14 allele T) + (number of PNPLA3 allele M) + (BMI × 0.1). A threshold of 7.27 was identified as cutoff for the predictive risk of alcoholic cirrhosis development in 36 years from the onset of at-risk alcohol consumption with 70.1% sensitivity and 78.7% specificity.

Conclusion

We developed the first score for alcoholic cirrhosis prediction that combines clinical and genetic factors.

New approaches for fibrosis regression in alcoholic cirrhosis

Liver fibrosis is a dynamic process of fibrinogenesis and fibrinolysis. It is sequelae of recurrent injury and inflammation to the liver. Only recently has there been significant progress in understanding the pathophysiology behind liver fibrosis. This has allowed for the development of identifiable targets for potential therapies. In this article we will discuss the underlying general cellular mechanisms that play a key role in the pathway of fibrinogenesis and fibrinolysis and then focus on the mechanisms that are key in alcohol-induced liver fibrosis. Challenges in formulating potential fibrosis therapies as well as current potential targets for liver fibrosis will be reviewed as well.

New therapeutic targets in alcoholic hepatitis

Alcoholic liver disease (ALD) is a leading cause of liver-related morbidity and mortality worldwide. ALD encompasses a spectrum of disorders including asymptomatic steatosis, steatohepatitis, fibrosis, cirrhosis and its related complications, and the acute-on-chronic state of alcoholic hepatitis. While multidisciplinary efforts continue to be aimed at curbing progression of this spectrum of disorders, there is an urgent need to focus our efforts on effective therapeutic interventions for alcoholic hepatitis (AH), the most severe form of ALD. AH is characterized by an abrupt development of jaundice and complications related to liver insufficiency and portal hypertension in patients with heavy alcohol intake. The mortality of patients with severe AH is very high (20-50 % at 3 months). The current therapeutic regimens are limited. The development of new therapies requires translational studies in human samples and suitable animal models that reproduce clinical and histological features of human AH. This review article summarizes the clinical syndrome, pre-clinical translational tools, and pathogenesis of AH at a molecular and cellular level, with the aim of identifying new targets of potential therapeutic intervention.

Toll-like receptor-mediated signaling cascade as a regulator of the inflammation network during alcoholic liver disease

Chronic abuse of alcohol leads to various histological abnormalities in the liver. These are conditions collectively known as alcoholic liver disease (ALD). Currently, ALD is considered to be one of the major causes of death worldwide. An impaired intestinal barrier with related endotoxemia is among the various pathogenetic factors. This is mainly characterized by circulating levels of lipopolysaccharide (LPS), considered critical for the onset of intra-hepatic inflammation. This in turn promotes hepatocellular damage and fibrosis in ALD. Elevated levels of LPS exert their effects by binding to Toll-like receptors (TLRs) which are expressed by all liver-resident cells. The activation of TLR signaling triggers an overproduction and release of some cytokines, which promote an autocatalytic cascade of other pro-inflammatory signals. In this review, we provide an overview of the mechanisms that sustain LPS-mediated activation of TLR signaling, reporting current experimental and clinical evidence of its role during inflammation in ALD.

Association between CD14 gene polymorphisms and cancer risk: a meta-analysis

Background

Two polymorphisms, -260C/T and -651C/T, in the CD14 gene have been implicated in susceptibility to cancer. However, the results remain inconclusive. This meta-analysis aimed to investigate the association between the two polymorphisms and risk of cancer.

Methods

All eligible case-control studies published up to March 2014 were identified by searching PubMed, Web of Science, CNKI and WanFang database. Pooled odds ratio (OR) with 95% confidence interval (CI) were used to access the strength of this association in fixed- or random-effects model.

Results

17 case-control studies from fourteen articles were included. Of those, there were 17 studies (4198 cases and 4194 controls) for -260C/T polymorphism and three studies (832 cases and 1190 controls) for -651C/T polymorphism. Overall, no significant associations between the two polymorphisms of CD14 gene and cancer risk were found. When stratified by ethnicity, cancer type and source of control, similar results were observed among them. In addition, in further subgroups analysis by Helicobacter pylori (H. pylori) infection status and tumor location in gastric cancer subgroup, we found that the CD14 -260C/T polymorphism may increase the risk of gastric cancer in H. pylori-infected individuals.

Conclusions

This meta-analysis suggests that the CD14 -260C/T polymorphism may increase the risk of gastric cancer in H. pylori-infected individuals. However, large and well-designed studies are warranted to validate our findings.