Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease.

BACKGROUND AND AIMS: Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. METHODS: We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholic steatohepatitis (NASH). Hepatic transcriptome was examined by RNA-Seq in a subset of NAFLD individuals (n = 121). Transcriptomic and deconvolution analyses were performed to identify biological pathways modulated by the risk allele. RESULTS: The rs13023138 C>G showed the most robust association with HCC in UK Biobank (p = 5.28E-4, OR = 1.32, 95% CI [1.1, 1.5]). In the liver biopsy cohort, rs13023138 G allele was independently associated with severe steatosis (OR 1.17, 95% CI 1.02-1.34; p = .01), NASH (OR 1.22, 95% CI 1.09-1.37; p < .001) and advanced fibrosis (OR 1.26, 95% CI 1.06-1.50; p = .007). At deconvolution analysis, rs13023138 G>C allele was linked to higher hepatic representation of M1 macrophages, paralleled by upregulation of pathways related to inflammation and higher expression of CXCR6. CONCLUSIONS: The PDCD1 rs13023138 G allele was associated with HCC development in the general population and with liver disease severity in patients at high risk of NASH.

Subclinical and clinical atherosclerosis in non-alcoholic fatty liver disease is associated with the presence of hypertension.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) is associated with increased cardiovascular (CV) risk. However, it is unclear whether NAFLD contributes independently to the development of CV disease. Our study aimed at assessing the differences in several indices of atherosclerosis, arterial stiffness and cardiac morphology among patients with isolated NAFLD, isolated hypertension (HT) or a combination of the two conditions. METHODS AND RESULTS: A total of 169 participants (mean age = 50.4 ± 10.2 yrs; males = 73.6%) were divided according to the presence of NAFLD and HT into three groups: only NAFLD (55 patients), only HT (49 patients), and NAFLD + HT (65 patients). Exclusion criteria were a BMI≥35 kg/m2 and a diagnosis of diabetes mellitus. Carotid ultrasonography was performed to measure markers of atherosclerosis and arterial stiffness. Cardiac remodeling was analyzed using echocardiography. The prevalence of subclinical and overt atherosclerosis was significantly higher in the NAFLD + HT patients as compared to the other two groups (atherosclerotic plaques: 43.1%, 10.9%, and 22.4% (p < 0.001) in NAFLD + HT, NAFLD, and HT groups, respectively). No differences were found among indices of arterial stiffening and cardiac remodeling across the three groups. In multivariate regression analysis, the coexistence of NAFLD and HT was an independent risk factor for overt atherosclerosis (OR = 4.88, CI 95% 1.14-20.93), while no association was found when either NAFLD or HT was considered alone. CONCLUSION: Overt atherosclerosis was significantly present only in NAFLD + HT patients, but not in patients with isolated NAFLD. This implies that the impact of NAFLD on vascular structure and function could depend on the coexistence of other major CV risk factors, such as HT.

Rare ATG7 genetic variants predispose patients to severe fatty liver disease.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver disorders and has a strong heritable component. The aim of this study was to identify new loci that contribute to severe NAFLD by examining rare variants. METHODS: We performed whole-exome sequencing in individuals with NAFLD and advanced fibrosis or hepatocellular carcinoma (n = 301) and examined the enrichment of likely pathogenic rare variants vs. the general population. This was followed by validation at the gene level. RESULTS: In patients with severe NAFLD, we observed an enrichment of the p.P426L variant (rs143545741 C>T; odds ratio [OR] 5.26, 95% CI 2.1-12.6; p = 0.003) of autophagy-related 7 (ATG7), which we characterized as a loss-of-function, vs. the general population, and an enrichment in rare variants affecting the catalytic domain (OR 13.9; 95% CI 1.9-612; p = 0.002). In the UK Biobank cohort, loss-of-function ATG7 variants increased the risk of cirrhosis and hepatocellular carcinoma (OR 3.30; 95% CI 1.1-7.5 and OR 12.30, 95% CI 2.6-36, respectively; p <0.001 for both). The low-frequency loss-of-function p.V471A variant (rs36117895 T>C) was also associated with severe NAFLD in the clinical cohort (OR 1.7; 95% CI 1.2-2.5; p = 0.003), predisposed to hepatocellular ballooning (p = 0.007) evolving to fibrosis in the Liver biopsy cohort (n = 2,268), and was associated with liver injury in the UK Biobank (aspartate aminotransferase levels, p <0.001), with a larger effect in severely obese individuals in whom it was linked to hepatocellular carcinoma (p = 0.009). ATG7 protein localized to periportal hepatocytes, particularly in the presence of ballooning. In the Liver Transcriptomic cohort (n = 125), ATG7 expression correlated with suppression of the TNFα pathway, which was conversely upregulated in p.V471A carriers. CONCLUSIONS: We identified rare and low-frequency ATG7 loss-of-function variants that promote NAFLD progression by impairing autophagy and facilitating ballooning and inflammation. LAY SUMMARY: We found that rare mutations in a gene called autophagy-related 7 (ATG7) increase the risk of developing severe liver disease in individuals with dysmetabolism. These mutations cause an alteration in protein function and impairment of self-renewal of cellular content, leading to liver damage and inflammation.

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

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and it is anticipated that it could become even more prevalent in parallel with an increase in the incidence of metabolic diseases closely related to NAFLD, such as obesity, type II diabetes, dyslipidemia, and arterial hypertension. In addition to liver impairment, NAFLD is associated with cardiovascular diseases. Fibrosis, atherosclerosis, and venous thrombosis are basically the pathogenic mechanisms behind these clinical manifestations, and all are plausibly associated with hypercoagulability that may, in turn, develop because of an imbalance of pro- vs. anticoagulants and the presence of such procoagulant molecular species as microvesicles, neutrophil extracellular traps (NETs), and inflammation. The assessment of hypercoagulability by means of thrombin generation is a global procedure that mimics the coagulation process occurring in vivo much better than any other coagulation test, and is considered to be the best candidate laboratory tool for assessing, with a single procedure, the balance of coagulation in NAFLD. In addition to defining the state of hypercoagulability, the assessment of thrombin generation could also be used to investigate, in clinical trials, the best approach (therapeutic and/or lifestyle changes) for minimizing hypercoagulability and, hence, the risk of cardiovascular diseases, progression to atherosclerosis, and liver fibrosis in patients with NAFLD.

TM6SF2/PNPLA3/MBOAT7 Loss-of-Function Genetic Variants Impact on NAFLD Development and Progression Both in Patients and in In Vitro Models.

BACKGROUND & AIMS: The I148M Patatin-like Phospholipase Domain-containing 3 (PNPLA3), the rs641738 in the Membrane bound O-acyltransferase domain containing 7-transmembrane channel-like 4 (MBOAT7-TMC4) locus, and the E167K Transmembrane 6 Superfamily Member 2 (TM6SF2) polymorphisms represent the main predisposing factors to nonalcoholic fatty liver disease (NAFLD) development and progression. We previously generated a full knockout of MBOAT7 in HepG2 cells (MBOAT7-/-), homozygous for I148M PNPLA3. Therefore, we aimed to investigate the synergic impact of the 3 at-risk variants on liver injury and hepatocellular carcinoma (HCC) in a large cohort of NAFLD patients, and create in vitro models of genetic NAFLD by silencing TM6SF2 in both HepG2 and MBOAT7-/- cells. METHODS: NAFLD patients (n = 1380), of whom 121 had HCC, were stratified with a semiquantitative score ranging from 0 to 3 according to the number of PNPLA3, TM6SF2, and MBOAT7 at-risk variants. TM6SF2 was silenced in HepG2 (TM6SF2-/-) and MBOAT7-/- (MBOAT7-/-TM6SF2-/-) through Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR/Cas9). RESULTS: In NAFLD patients, the additive weight of these mutations was associated with liver disease severity and an increased risk of developing HCC. In HepG2 cells, TM6SF2 silencing altered lipid composition and induced the accumulation of microvesicular lipid droplets (LDs), whereas the MBOAT7-/-TM6SF2-/- cells showed a mixed microvesicular/macrovesicular pattern of LDs. TM6SF2 deletion strongly affected endoplasmic reticulum and mitochondria ultrastructures, thus increasing endoplasmic reticulum/oxidative stress. The mitochondrial number was increased in both TM6SF2-/- and MBOAT7-/-TM6SF2-/- models, suggesting an unbalancing in mitochondrial dynamics, and the silencing of both MBOAT7 and TM6SF2 impaired mitochondrial activity with a shift toward anaerobic glycolysis. MBOAT7-/-TM6SF2-/- cells also showed the highest proliferation rate. Finally, the re-overexpression of MBOAT7 and/or TM6SF2 reversed the metabolic and tumorigenic features observed in the compound knockout model. CONCLUSIONS: The co-presence of the 3 at-risk variants impacts the NAFLD course in both patients and experimental models, affecting LD accumulation, mitochondrial functionality, and metabolic reprogramming toward HCC.

Aramchol in patients with nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled phase 2b trial.

Nonalcoholic steatohepatitis (NASH), a chronic liver disease without an approved therapy, is associated with lipotoxicity and insulin resistance and is a major cause of cirrhosis and hepatocellular carcinoma. Aramchol, a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1) improved steatohepatitis and fibrosis in rodents and reduced steatosis in an early clinical trial. ARREST, a 52-week, double-blind, placebo-controlled, phase 2b trial randomized 247 patients with NASH (n = 101, n = 98 and n = 48 in the Aramchol 400 mg, 600 mg and placebo arms, respectively; NCT02279524 ). The primary end point was a decrease in hepatic triglycerides by magnetic resonance spectroscopy at 52 weeks with a dose of 600 mg of Aramchol. Key secondary end points included liver histology and alanine aminotransferase (ALT). Aramchol 600 mg produced a placebo-corrected decrease in liver triglycerides without meeting the prespecified significance (-3.1, 95% confidence interval (CI) -6.4 to 0.2, P = 0.066), precluding further formal statistical analysis. NASH resolution without worsening fibrosis was achieved in 16.7% (13 out of 78) of Aramchol 600 mg versus 5% (2 out of 40) of the placebo arm (odds ratio (OR) = 4.74, 95% CI = 0.99 to 22.7) and fibrosis improvement by ≥1 stage without worsening NASH in 29.5% versus 17.5% (OR = 1.88, 95% CI = 0.7 to 5.0), respectively. The placebo-corrected decrease in ALT for 600 mg was -29.1 IU l-1 (95% CI = -41.6 to -16.5). Early termination due to adverse events (AEs) was <5%, and Aramchol 600 and 400 mg were safe, well tolerated and without imbalance in serious or severe AEs between arms. Although the primary end point of a reduction in liver fat did not meet the prespecified significance level with Aramchol 600 mg, the observed safety and changes in liver histology and enzymes provide a rationale for SCD1 modulation as a promising therapy for NASH and fibrosis and are being evaluated in an ongoing phase 3 program.

Long-term outcomes and predictive ability of non-invasive scoring systems in patients with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: Non-invasive scoring systems (NSS) are used to identify patients with non-alcoholic fatty liver disease (NAFLD) who are at risk of advanced fibrosis, but their reliability in predicting long-term outcomes for hepatic/extrahepatic complications or death and their concordance in cross-sectional and longitudinal risk stratification remain uncertain. METHODS: The most common NSS (NFS, FIB-4, BARD, APRI) and the Hepamet fibrosis score (HFS) were assessed in 1,173 European patients with NAFLD from tertiary centres. Performance for fibrosis risk stratification and for the prediction of long-term hepatic/extrahepatic events, hepatocarcinoma (HCC) and overall mortality were evaluated in terms of AUC and Harrell's c-index. For longitudinal data, NSS-based Cox proportional hazard models were trained on the whole cohort with repeated 5-fold cross-validation, sampling for testing from the 607 patients with all NSS available. RESULTS: Cross-sectional analysis revealed HFS as the best performer for the identification of significant (F0-1 vs. F2-4, AUC = 0.758) and advanced (F0-2 vs. F3-4, AUC = 0.805) fibrosis, while NFS and FIB-4 showed the best performance for detecting histological cirrhosis (range AUCs 0.85-0.88). Considering longitudinal data (follow-up between 62 and 110 months), NFS and FIB-4 were the best at predicting liver-related events (c-indices>0.7), NFS for HCC (c-index = 0.9 on average), and FIB-4 and HFS for overall mortality (c-indices >0.8). All NSS showed limited performance (c-indices <0.7) for extrahepatic events. CONCLUSIONS: Overall, NFS, HFS and FIB-4 outperformed APRI and BARD for both cross-sectional identification of fibrosis and prediction of long-term outcomes, confirming that they are useful tools for the clinical management of patients with NAFLD at increased risk of fibrosis and liver-related complications or death. LAY SUMMARY: Non-invasive scoring systems are increasingly being used in patients with non-alcoholic fatty liver disease to identify those at risk of advanced fibrosis and hence clinical complications. Herein, we compared various non-invasive scoring systems and identified those that were best at identifying risk, as well as those that were best for the prediction of long-term outcomes, such as liver-related events, liver cancer and death.

Reduced incidence of type 2 diabetes in patients with chronic hepatitis C virus infection cleared by direct-acting antiviral therapy: A prospective study.

AIM: To assess the effect of hepatitis C virus (HCV) eradication on type 2 diabetes mellitus (T2DM). incidence. METHODS: A prospective multicentre case-control study was performed, which included 2426 patients with HCV, 42% of whom had liver fibrosis stage F0-F2 and 58% of whom had liver fibrosis stage F3-F4. The study population consisted of a control group including 1099 untreated patients and 1327 cases treated with direct-acting antivirals (DAAs). T2DM incidence was assessed during a median (interquartile range) follow-up period of 30 (28-42) months. Risk factors for T2DM were assessed using a Cox regression model (relative risk [RR], hazard ratio [HR], Kaplan-Meier analysis). Insulin sensitivity was evaluated by homeostatic model assessment (HOMA) and changes by repeated-measures ANOVA. Factors independently associated with T2DM were assessed by multivariate analysis. RESULTS: The absolute incidence of T2DM for controls and cases was 28 and 7/1000 person-years, respectively (P = 0.001). In cases compared to controls, HCV clearance reduced the RR and HR of T2DM by 81% and 75% to 93%, respectively (P = 0.001). It was calculated that, for every 15 patients who obtained HCV clearance, one case of T2DM was saved. HCV clearance was associated with significant reductions in HOMA-insulin resistance and HOMA-ß-cell function and an increase in HOMA-insulin sensitivity, as assessed in 384 patients before and after HCV clearance. At multivariate analysis, HCV clearance emerged as independently associated with a reduced T2DM risk. CONCLUSION: The results showed that HCV clearance by DAA treatment reduces T2DM incidence probably by restoring the HCV-induced alteration of glucose homeostasis mechanisms.

MBOAT7 down-regulation by genetic and environmental factors predisposes to MAFLD.

Metabolic associated fatty liver disease (MAFLD) encompasses a broad spectrum of hepatic disorders, which include steatosis, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, that is a critical risk factor for hepatocellular carcinoma (HCC) development. Its pathogenesis is intertwined with obesity and type 2 diabetes (T2D). However, the predisposition to develop MAFLD is severely influenced by environmental and inherited cues. The rs641738 variant close to MBOAT7 gene has been identified by a genome-wide association screening in heavy drinkers. Although this variant has been associated with the entire spectrum of MAFLD, these results have not been completely replicated and the debate is still opened. Thus, functional studies that unravel the biological mechanisms underlying the genetic association with fatty liver are required. This review aims to summarize the clinical and experimental findings regarding the rs641738 variation and MBOAT7 function, with the purpose to shed light to its role as novel player in MAFLD pathophysiology.

Presence of Serum Antinuclear Antibodies Does Not Impact Long-Term Outcomes in Nonalcoholic Fatty Liver Disease.

INTRODUCTION: We investigated the longitudinal impact of antinuclear antibody (ANA) on clinical outcomes and survival in nonalcoholic fatty liver disease (NAFLD). METHODS: ANA were found in 16.9% of 923 biopsy-proven NAFLD patients, but none of them had histologic autoimmune hepatitis (AIH) or developed AIH after a mean follow-up of 106±50 months. RESULTS: Although ANA-positive cases had a higher prevalence of nonalcoholic steatohepatitis at baseline, the occurrence of liver-related events, hepatocellula carcinoma, cardiovascular events, extrahepatic malignancy, and overall survival were similar to ANA-negative. DISCUSSION: Once AIH has been ruled out, the long-term outcomes and survival are unaffected by the presence of ANA in patients with NAFLD.

Dysmetabolic Hyperferritinemia and Dysmetabolic Iron Overload Syndrome (DIOS): Two Related Conditions or Different Entities?

Hyperferritinemia is observed in one-third of patients with non-alcoholic fatty liver disease (NAFLD) and Metabolic Syndrome (MetS). The condition characterized by increased body iron stores associated with components of MetS has been defined as Dysmetabolic Iron Overload Syndrome (DIOS). DIOS represents the most frequent iron overload condition, since it is observed in 15% of patients with MetS and in half of those with NAFLD and its clinical presentation overlaps almost completely with that of dysmetabolic hyperferritinemia (DH). The pathogenetic mechanisms linking insulin resistance (IR), NAFLD and DIOS to iron overload are still debated. Hepcidin seems to play a role in iron accumulation in DIOS and NAFLD patients who show elevated serum hepcidin levels. The iron challenge does not restrain iron absorption despite adequate hepcidin production, suggesting that an impaired hepcidin activity rather than a deficit of hormone production underlies DIOS pathogenesis. Acquired and genetic factors are recognized to contribute to iron accumulation in NAFLD whereas additional studies are required to clearly demonstrate whether the same or different genetic factors lead to iron overload in DIOS. Finally, iron depletion by phlebotomy, together with the modification of diet and life-style habits, represents the therapeutic approach to decrease metabolic alterations and liver enzymes in NAFLD and DIOS patients. In this review, we summarized the current knowledge on the dysregulation of iron homeostasis in NAFLD and DIOS in the attempt to clarify whether they are different or more likely strictly related conditions, sharing the same pathogenic cause i.e. the MetS.

Impact of natural neuromedin-B receptor variants on iron metabolism.

Iron overload heritability remains partly unexplained. By performing whole exome sequencing in three patients with a clinical phenotype of hemochromatosis not accounted by known genetic risk factors, we identified in all patients rare variants predicted to alter activity of Neuromedin-B receptor (NMBR). Coding NMBR mutations were enriched in 129 patients with hereditary hemochromatosis or iron overload phenotype, as compared to ethnically matched controls, including 100 local healthy blood donors and 1000Genomes project participants (15.5% vs 5%, P = .0038 at burden test), and were associated with higher transferrin saturation in regular blood donors (P = .04). Consistently, in 191 patients with nonalcoholic fatty liver, the most common low-frequency p.L390 M variant was independently associated with higher ferritin (P = .03). In 58 individuals, who underwent oral iron challenge, carriage of the p.L390 M variant was associated with higher transferrin saturation and lower hepcidin release. Furthermore, the circulating concentration of the natural NMBR ligand, Neuromedin-B, was reduced in response to iron challenge. It was also decreased in individuals carrying the p.L390 M variant and with hemochromatosis in parallel with increased transferrin saturation. In mice, Nmbr was induced by chronic dietary iron overload in the liver, gut, pancreas, spleen, and skeletal muscle, while Nmb was downregulated in gut, pancreas and spleen. Finally, Nmb amplified holo-transferrin dependent induction of hepcidin in primary mouse hepatocytes, which was associated with Jak2 induction and abolished by the NMBR antagonist PD168368. In conclusion, NMBR natural variants were enriched in patients with iron overload, and associated with facilitated iron absorption, possibly related to a defect of iron-induced hepcidin release.

Liver fibrosis by FibroScan® independently of established cardiovascular risk parameters associates with macrovascular and microvascular complications in patients with type 2 diabetes.

BACKGROUND & AIMS: Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are closely associated, and liver fibrosis has been related to macrovascular complications. We examined whether liver fibrosis, diagnosed by FibroScan® , correlates with chronic vascular complications in a cohort of T2DM. METHODS: We recruited 394 outpatients with T2DM attending five Italian diabetes centres who underwent liver ultrasonography (US), FibroScan® and extensive evaluation of macrovascular and microvascular diabetic complications. RESULTS: Steatosis by US was present in 89%. Almost all patients (96%) were on hypoglycaemic drugs, 58% had at least one chronic vascular complication, 19% a macrovascular complication (prior myocardial infarction and/or ischaemic stroke) and 33% a microvascular one (26% chronic kidney disease [CKD]; 16% retinopathy; 6% neuropathy). In all, 171 (72%) patients had CAP ≥ 248dB/m (ie hepatic steatosis), whereas 83 (21%) patients had LSM ≥ 7.0/6.2 kPa (M/XL probes) (significant liver fibrosis). CAP was not associated with any macro/microvascular complications, whereas LSM ≥ 7.0/6.2 kPa was independently associated with prior cardiovascular disease (adjusted OR 3.3, 95%CI 1.2-8.8; P = .02) and presence of microvascular complications (adjusted OR 4.2, 95%CI 1.5-11.4; P = .005), mainly CKD (adjusted OR 3.6, 95%CI 1.3-10.1; P = .01) and retinopathy (adjusted OR 3.7, CI 95% 1.2-11.9; P = .02). Neither diabetes duration nor haemoglobin A1c differed according to CAP or LSM values. CONCLUSION: Significant fibrosis, detected by FibroScan® , is independently associated with increased prevalence of macrovascular and microvascular complications, thus opening a new scenario in the use of this tool for a comprehensive evaluation of hepatic and vascular complications in patients with T2DM.

Combined use of Genetic Polymorphisms and Elastographic Techniques in NAFLD: Fact or Fiction?

Non-alcoholic fatty liver disease (NAFLD) includes liver diseases ranging from simple steatosis to progressive forms characterized by high rates of complications and mortality, namely fibrosis, cirrhosis and hepatocellular carcinoma. Identification of patients with simple steatosis who will evolve to a more severe liver disease would allow better management of risk factors. Liver biopsy is the gold standard for the staging of NAFLD, however given its invasiveness it is not widely applicable. FibroScan® has emerged as a reliable non-invasive tool for the identification of both hepatic steatosis and fibrosis, by providing two parameters called CAP (controlled attenuation parameter) and LSM (liver stiffness measurement). However, there is no consensus in literature on definite cut-offs, and some drawbacks in differentiating advanced grades of steatosis and diagnosing mild stages of fibrosis and are still present. In addition, some genetic polymorphisms, namely PNPLA3, TM6SF2 and MBOAT7, represent critical determinants in the pathogenesis of liver steatosis and in the progression of liver damage and could be used in this diagnostic setting. Despite data on the role of FibroScan® in the identification of liver steatosis and fibrosis and on the influence of genetic polymorphisms in the onset and progression of liver disease are extensive in the literature, very few studies have explored the role of their combination in NAFLD diagnosis and in the prediction of evolving disease. This emphasizes the need for a great effort in this field in order to improve clinicians' diagnostic ability in everyday practice, avoiding invasive procedures when unnecessary and preventing NAFLD complications.

Protein phosphatase 1 regulatory subunit 3B gene variation protects against hepatic fat accumulation and fibrosis in individuals at high risk of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver damage and has a strong genetic component. The rs4841132 G>A variant, modulating the expression of protein phosphatase 1 regulatory subunit 3B (PPP1R3B), which is involved in glycogen synthesis, has been reported to reduce the risk of NAFLD but at the same time may favor liver disease by facilitating glycogen accumulation. The aim of this study was to assess the impact of rs4841132 on development of histologic steatosis and fibrosis in 1,388 European individuals in a liver biopsy cohort, on NAFLD hepatocellular carcinoma in a cross-sectional Italian cohort (n = 132 cases), and on liver disease at the population level in the United Kingdom Biobank cohort. We investigated the underlying mechanism by examining the impact of the variant on gene expression profiles. In the liver biopsy cohort, the rs4841132 minor A allele was associated with protection against steatosis (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42-0.95; P = 0.03) and clinically significant fibrosis (OR, 0.35; 95% CI, 0.14-0.87; P = 0.02) and with reduced circulating cholesterol (P = 0.02). This translated into protection against hepatocellular carcinoma development (OR, 0.22; 95% CI, 0.07-0.70; P = 0.01). At the population level, the rs4841132 variation was not associated with nonalcoholic or nonviral diseases of the liver but was associated with lower cholesterol (P = 1.7 × 10-8). In individuals with obesity, the A allele protecting against steatosis was associated with increased PPP1R3B messenger RNA expression and activation of lipid oxidation and with down-regulation of pathways related to lipid metabolism, inflammation, and cell cycle. Conclusion: The rs4841132 A allele is associated with protection against hepatic steatosis and fibrosis in individuals at high risk of NAFLD but not in the general population and against dyslipidemia. The mechanism may be related to modulation of PPP1R3B expression and hepatic lipid metabolism. (Hepatology Communications 2018;2:666-675).

PCSK9 deficiency results in increased ectopic fat accumulation in experimental models and in humans.

Background Proprotein convertase subtilisin kexin type 9 (PCSK9) regulates low-density lipoprotein and very low-density lipoprotein receptor expression in several tissues. Here we evaluated whether PCSK9 may modulate the handling of triglycerides in the liver and peripheral tissues. Methods Subjects from the PLIC cohort were genotyped for the loss-of-function PCSK9 R46L variant and characterized for clinical and biochemical parameters, total and android fat mass, hepatic steatosis and epicardial fat thickness. Visceral adipose tissue and subcutaneous adipose tissue in PCSK9 KO and wild type mice were quantified by nuclear magnetic resonance imaging. Results Carriers of the R46L variant ( n = 13) had lower low-density lipoprotein cholesterol levels, higher body mass index and increased percentage of total and android fat masses compared with non-carriers ( n = 521). R46L variant associated with a two-fold increase prevalence of hepatic steatosis and higher epicardial fat thickness. These observations were replicated in PCSK9 KO mice, which showed increased visceral adipose tissue (but not subcutaneous adipose tissue) when fed chow or high-fat diet for 20 weeks, compared with wild type mice. Conclusions These data suggest that genetically determined PCSK9 deficiency might be associated with ectopic fat accumulation.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study.

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Ovarian senescence increases liver fibrosis in humans and zebrafish with steatosis.

Contrasting data exist on the effect of gender and menopause on the susceptibility, development and liver damage progression in non-alcoholic fatty liver disease (NAFLD). Our aim was to assess whether menopause is associated with the severity of liver fibrosis in individuals with NAFLD and to explore the issue of ovarian senescence in experimental liver steatosis in zebrafish. In 244 females and age-matched males with biopsy-proven NAFLD, we assessed anthropometric, biochemical and metabolic features, including menopausal status (self-reported); liver biopsy was scored according to 'The Pathology Committee of the NASH Clinical Research Network'. Young and old male and female zebrafish were fed for 24 weeks with a high-calorie diet. Weekly body mass index (BMI), histopathological examination and quantitative real-time PCR analysis on genes involved in lipid metabolism, inflammation and fibrosis were performed. In the entire cohort, at multivariate logistic regression, male gender [odds ratio (OR): 1.408, 95% confidence interval (95% CI): 0.779-2.542, P=0.25] vs women at reproductive age was not associated with F2-F4 fibrosis, whereas a trend was observed for menopause (OR: 1.752, 95% CI: 0.956-3.208, P=0.06). In women, menopause (OR: 2.717, 95% CI: 1.020-7.237, P=0.04) was independently associated with F2-F4 fibrosis. Similarly, in overfed zebrafish, old female fish with failing ovarian function [as demonstrated by extremely low circulating estradiol levels (1.4±0.1 pg/µl) and prevailing presence of atretic follicles in the ovaries] developed massive steatosis and substantial fibrosis (comparable with that occurring in males), whereas young female fish developed less steatosis and were totally protected from the development of fibrosis. Ovarian senescence significantly increases the risk of fibrosis severity both in humans with NAFLD and in zebrafish with experimental steatosis.

Juvenile hemochromatosis associated with heterozygosity for novel hemojuvelin mutations and with unknown cofactors.

BACKGROUND & AIMS: Juvenile hemochromatosis (JH) is a rare autosomal recessive disorder characterized by severe early-onset iron overload, caused by mutations in hemojuvelin (HJV), hepcidin (HAMP), or a combination of genes regulating iron metabolism. Here we describe two JH cases associated with simple heterozygosity for novel HJV mutations and unknown genetic factors. Case 1: A 12 year-old male from Central Italy with beta-thalassemia trait, increased aminotransferases, ferritin 9035 ng/ml and transferrin saturation 84%, massive hepatocellular siderosis and hepatic bridging fibrosis. Case 2: A 12 year-old female from Northern Italy with ferritin 467 ng/ml, transferrin saturation 87-95%, and moderate hepatic iron overload. MATERIAL AND METHODS: Direct sequencing of hemochromatosis genes (HFE-TfR2-HJV-HAMP-FPN-1) was performed in the children and siblings. RESULTS: In case 1, we detected heterozygosity for a novel HJV mutation (g.3659_3660insG), which was inherited together with the beta thalassemia trait from the father, who (as well as the mother) had normal iron parameters. In case 2, we detected another novel HJV mutation (g.2297delC) in heterozygosity, which was inherited from the mother, affected by mild iron deficiency. The father had normal iron stores. Both mutations are frameshifts determining premature stop codons. No other disease causing variant was detected. CONCLUSION: Although beta-thalassemia trait was a possible cofactor of iron overload in case 1, iron overload cannot be explained by simple heterozygosity for HJV mutations in both cases. Other genetic factors should be investigated, and further studies are needed to understand genotype-phenotype correlations in JH.