Unraveling inflammatory responses using systems genetics and gene-environment interactions in macrophages.

Many common diseases have an important inflammatory component mediated in part by macrophages. Here we used a systems genetics strategy to examine the role of common genetic variation in macrophage responses to inflammatory stimuli. We examined genome-wide transcript levels in macrophages from 92 strains of the Hybrid Mouse Diversity Panel. We exposed macrophages to control media, bacterial lipopolysaccharide (LPS), or oxidized phospholipids. We performed association mapping under each condition and identified several thousand expression quantitative trait loci (eQTL), gene-by-environment interactions, and eQTL "hot spots" that specifically control LPS responses. We used siRNA knockdown of candidate genes to validate an eQTL hot spot in chromosome 8 and identified the gene 2310061C15Rik as a regulator of inflammatory responses in macrophages. We have created a public database where the data presented here can be used as a resource for understanding many common inflammatory traits that are modeled in the mouse and for the dissection of regulatory relationships between genes.

Indole-3-Propionic Acid Protects Against Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a common but poorly understood form of heart failure, characterized by impaired diastolic function. It is highly heterogeneous with multiple comorbidities, including obesity and diabetes, making human studies difficult. METHODS: Metabolomic analyses in a mouse model of HFpEF showed that levels of indole-3-propionic acid (IPA), a metabolite produced by gut bacteria from tryptophan, were reduced in the plasma and heart tissue of HFpEF mice as compared with controls. We then examined the role of IPA in mouse models of HFpEF as well as 2 human HFpEF cohorts. RESULTS: The protective role and therapeutic effects of IPA were confirmed in mouse models of HFpEF using IPA dietary supplementation. IPA attenuated diastolic dysfunction, metabolic remodeling, oxidative stress, inflammation, gut microbiota dysbiosis, and intestinal epithelial barrier damage. In the heart, IPA suppressed the expression of NNMT (nicotinamide N-methyl transferase), restored nicotinamide, NAD+/NADH, and SIRT3 (sirtuin 3) levels. IPA mediates the protective effects on diastolic dysfunction, at least in part, by promoting the expression of SIRT3. SIRT3 regulation was mediated by IPA binding to the aryl hydrocarbon receptor, as Sirt3 knockdown diminished the effects of IPA on diastolic dysfunction in vivo. The role of the nicotinamide adenine dinucleotide circuit in HFpEF was further confirmed by nicotinamide supplementation, Nnmt knockdown, and Nnmt overexpression in vivo. IPA levels were significantly reduced in patients with HFpEF in 2 independent human cohorts, consistent with a protective function in humans, as well as mice. CONCLUSIONS: Our findings reveal that IPA protects against diastolic dysfunction in HFpEF by enhancing the nicotinamide adenine dinucleotide salvage pathway, suggesting the possibility of therapeutic management by either altering the gut microbiome composition or supplementing the diet with IPA.

An integrative systems genetic analysis of mammalian lipid metabolism.

Dysregulation of lipid homeostasis is a precipitating event in the pathogenesis and progression of hepatosteatosis and metabolic syndrome. These conditions are highly prevalent in developed societies and currently have limited options for diagnostic and therapeutic intervention. Here, using a proteomic and lipidomic-wide systems genetic approach, we interrogated lipid regulatory networks in 107 genetically distinct mouse strains to reveal key insights into the control and network structure of mammalian lipid metabolism. These include the identification of plasma lipid signatures that predict pathological lipid abundance in the liver of mice and humans, defining subcellular localization and functionality of lipid-related proteins, and revealing functional protein and genetic variants that are predicted to modulate lipid abundance. Trans-omic analyses using these datasets facilitated the identification and validation of PSMD9 as a previously unknown lipid regulatory protein. Collectively, our study serves as a rich resource for probing mammalian lipid metabolism and provides opportunities for the discovery of therapeutic agents and biomarkers in the setting of hepatic lipotoxicity.

Tenofovir Alafenamide versus Tenofovir Disoproxil Fumarate for Preventing Vertical Transmission in Chronic Hepatitis B Mothers: A Systematic Review and Meta-Analysis.

OBJECTIVE: International guidelines recommend maternal tenofovir disoproxil fumarate (TDF) therapy accompanied by infant immunoprophylaxis to prevent HBV mother-to-child transmission (MTCT) in highly viremic mothers. However, pooled analyses for tenofovir alafenamide (TAF) effects and comparisons between the two regimens are lacking. DESIGN: In this meta-analysis, pairs of independent reviewers performed multiple database searches from inception to March 31, 2024, and extracted data from cohort studies and RCTs in highly viremic mothers. The outcomes of interest were the reduction of MTCT and safety in the TDF-treated, TAF-treated, and control groups. RESULTS: We included 31 studies with 2,588 highly viremic mothers receiving TDF, 280 receiving TAF, and 1,600 receiving no treatment. Compared to the control, TDF therapy reduced the MTCT rate in infants aged 6-12 months (risk ratio: 0.10, 95% confidence interval 0.07-0.16). Pairwise meta-analysis between TAF and TDF revealed similar effects on reducing MTCT (risk ratio: 1.09, 95% confidence interval 0.16-7.61). Network meta-analysis showed the equal efficacy of the two regimens in reducing MTCT (risk ratio: 1.09, 95% confidence interval 0.15-7.65). The surface under the cumulative ranking curve revealed TDF as the best regimen compared with TAF (probability ranking: 0.77 vs. 0.72), while receiving a placebo during pregnancy had the lowest efficacy (probability ranking 0.01). There were no safety concerns for mothers and infants in all regimens. CONCLUSION: Compared to placebo or no treatment, maternal TDF and TAF prophylaxis are equally effective and without safety concerns in reducing MTCT in highly viremic mothers.

Integrative analysis of liver-specific non-coding regulatory SNPs associated with the risk of coronary artery disease.

Genetic factors underlying coronary artery disease (CAD) have been widely studied using genome-wide association studies (GWASs). However, the functional understanding of the CAD loci has been limited by the fact that a majority of GWAS variants are located within non-coding regions with no functional role. High cholesterol and dysregulation of the liver metabolism such as non-alcoholic fatty liver disease confer an increased risk of CAD. Here, we studied the function of non-coding single-nucleotide polymorphisms in CAD GWAS loci located within liver-specific enhancer elements by identifying their potential target genes using liver cis-eQTL analysis and promoter Capture Hi-C in HepG2 cells. Altogether, 734 target genes were identified of which 121 exhibited correlations to liver-related traits. To identify potentially causal regulatory SNPs, the allele-specific enhancer activity was analyzed by (1) sequence-based computational predictions, (2) quantification of allele-specific transcription factor binding, and (3) STARR-seq massively parallel reporter assay. Altogether, our analysis identified 1,277 unique SNPs that display allele-specific regulatory activity. Among these, susceptibility enhancers near important cholesterol homeostasis genes (APOB, APOC1, APOE, and LIPA) were identified, suggesting that altered gene regulatory activity could represent another way by which genetic variation regulates serum lipoprotein levels. Using CRISPR-based perturbation, we demonstrate how the deletion/activation of a single enhancer leads to changes in the expression of many target genes located in a shared chromatin interaction domain. Our integrative genomics approach represents a comprehensive effort in identifying putative causal regulatory regions and target genes that could predispose to clinical manifestation of CAD by affecting liver function.

The function role of HIGD1A in nonalcoholic steatohepatitis from chronic hepatitis B.

BACKGROUND: Accompanied by the growing prevalence of nonalcoholic fatty liver disease (NAFLD), the coexistence of chronic hepatitis B (CHB) and NAFLD has increased. In the context of CHB, there is limited understanding of the factors that influence the development of NASH. METHODS: We enrolled CHB combined NAFLD patients who had liver biopsy and divided them to NASH vs. non-NASH groups. A whole transcriptome chip was used to examine the expression profiles of long noncoding RNAs (lncRNAs) and mRNA in biopsied liver tissues. The function analysis of HIGD1A were performed. We knocked down or overexpressed HIGD1A in HepG2.2.15 cells by transient transfection of siRNA-HIGD1A or pcDNA-HIGD1A. In vivo investigations were conducted using hepatitis B virus (HBV) transgenic mice. RESULTS: In 65 patients with CHB and NAFLD, 28 were patients with NASH, and 37 were those without NASH. After screening 582 differentially expressed mRNAs, GO analysis revealed differentially expressed mRNAs acting on nicotinamide adenine dinucleotide phosphate (NADPH), which influenced redox enzyme activity. KEGG analysis also shown that they were involved in the NAFLD signaling pathway. The function analysis revealed that HIGD1A was associated with the mitochondrion. Then, both in vivo and in vitro CHB model, HIGD1A was significantly higher in the NASH group than in the non-NASH group. HIGD1A knockdown impaired mitochondrial transmembrane potential and induced cell apoptosis in HepG2.2.15 cells added oleic acid and palmitate. On the contrary, hepatic HIGD1A overexpression ameliorated free fatty acids-induced apoptosis and oxidative stress. Furthermore, HIGD1A reduced reactive oxygen species (ROS) level by increasing glutathione (GSH) expression, but Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/Acetyl-CoA carboxylase (ACC) pathway was not involved. CONCLUSION: Both in vivo and in vitro CHB model, an upward trend of HIGD1A was observed in the NASH-related inflammatory response. HIGDIA played a protective role in cells against oxidative stress. Our data suggested that HIGD1A may be a positive regulator of NASH within the CHB context.

Performance of MAST, FAST, and MEFIB in predicting metabolic dysfunction-associated steatohepatitis.

BACKGROUND AND AIM: To identify individuals with metabolic dysfunction-associated steatohepatitis (MASH) or "at-risk" MASH among patients with metabolic dysfunction-associated steatotic liver disease (MASLD), three noninvasive models are available with satisfactory efficiency, which include magnetic resonance imaging [MRI]- AST (MAST), FibroScan-AST (FAST score), and magnetic resonance elastography [MRE] plus FIB-4 (MEFIB). We aimed to evaluate the most accurate approach for diagnosing MASH or "at-risk" MASH. METHODS: We included 108 biopsy-proven MASLD patients who underwent simultaneous assessment of MRE, MRI proton density fat fraction (MRI-PDFF), and FibroScan scans. Compared with the histological diagnosis, we analyzed the AUC of each model and assessed the accuracy. RESULTS: Our study cohort consisted of 64.8% of MASH and 25.9% of "at-risk" MASH. When analyzing the performance of each model for the diagnostic accuracy of MASH, we found that the AUC [95% CI] of MAST was comparable to FAST (0.803 [0.719-0.886] vs 0.799 [0.707-0.891], P = 0.930) and better than MEFIB (0.671 [0.571-0.772], P = 0.005). Similar findings were observed in the "at-risk" MASH patients. The AUCs [95% CI] for MAST, FAST, and MEFIB were 0.810 [0.719-0.900], 0.782 [0.689-0.874], and 0.729 [0.619-0.838], respectively. The models of MAST and FAST had comparable AUCs (P = 0.347), which were statistically significantly higher than that of MEFIB (P = 0.041). Additionally, the cutoffs for diagnosis of MASH were lower than "at-risk" MASH. CONCLUSION: MAST and FAST performed better than MEFIB in diagnosing "at-risk" MASH and MASH using lower cutoff values. Our findings provided evidence for selecting the most accurate noninvasive model to identify patients with MASH or at-risk MASH.

MBOAT7-driven lysophosphatidylinositol acylation in adipocytes contributes to systemic glucose homeostasis.

We previously demonstrated that antisense oligonucleotide-mediated knockdown of Mboat7, the gene encoding membrane bound O-acyltransferase 7, in the liver and adipose tissue of mice promoted high fat diet-induced hepatic steatosis, hyperinsulinemia, and systemic insulin resistance. Thereafter, other groups showed that hepatocyte-specific genetic deletion of Mboat7 promoted striking fatty liver and NAFLD progression in mice but does not alter insulin sensitivity, suggesting the potential for cell autonomous roles. Here, we show that MBOAT7 function in adipocytes contributes to diet-induced metabolic disturbances including hyperinsulinemia and systemic insulin resistance. We generated Mboat7 floxed mice and created hepatocyte- and adipocyte-specific Mboat7 knockout mice using Cre-recombinase mice under the control of the albumin and adiponectin promoter, respectively. Here, we show that MBOAT7 function in adipocytes contributes to diet-induced metabolic disturbances including hyperinsulinemia and systemic insulin resistance. The expression of Mboat7 in white adipose tissue closely correlates with diet-induced obesity across a panel of ∼100 inbred strains of mice fed a high fat/high sucrose diet. Moreover, we found that adipocyte-specific genetic deletion of Mboat7 is sufficient to promote hyperinsulinemia, systemic insulin resistance, and mild fatty liver. Unlike in the liver, where Mboat7 plays a relatively minor role in maintaining arachidonic acid-containing PI pools, Mboat7 is the major source of arachidonic acid-containing PI pools in adipose tissue. Our data demonstrate that MBOAT7 is a critical regulator of adipose tissue PI homeostasis, and adipocyte MBOAT7-driven PI biosynthesis is closely linked to hyperinsulinemia and insulin resistance in mice.

Long-term Treatment With Tenofovir Alafenamide for Chronic Hepatitis B Results in High Rates of Viral Suppression and Favorable Renal and Bone Safety.

OBJECTIVES: Results from two Phase 3 studies, through 2 years, in chronic hepatitis B infection (CHB) showed tenofovir alafenamide (TAF) had similar efficacy to tenofovir disoproxil fumarate (TDF) with superior renal and bone safety. Here, we report updated results through 5 years. METHODS: Patients with HBeAg-negative or -positive CHB with or without compensated cirrhosis were randomized (2:1) to TAF 25 mg or TDF 300 mg once daily in double-blind (DB) fashion for up to 3 years, followed by open-label (OL) TAF up to 8 years. Efficacy (antiviral, biochemical, serologic), resistance (deep sequencing of polymerase/reverse transcriptase and phenotyping), and safety, including renal and bone parameters, were evaluated by pooled analyses. RESULTS: Of 1298 randomized and treated patients, 866 receiving TAF (DB and OL) and 432 receiving TDF with rollover to OL TAF at year 2 (n = 180; TDF→TAF3y) or year 3 (n = 202; TDF→TAF2y) were included. Fifty (4%) TDF patients who discontinued during DB were excluded. At year 5, 85%, 83%, and 90% achieved HBV DNA < 29 IU/mL (missing = failure) in the TAF, TDF→TAF3y, and TDF→TAF2y groups, respectively; no patient developed TAF or TDF resistance. Median eGFR (by Cockcroft-Gault) declined < 2.5 mL/min, and mean declines of < 1% in hip and spine bone mineral density were seen at year 5 in the TAF group; patients in the TDF→TAF groups had improvements in these parameters at year 5 after switching to OL TAF. CONCLUSIONS: Long-term TAF treatment resulted in high rates of viral suppression, no resistance, and favorable renal and bone safety.

The Use of Tenofovir Disoproxil Fumarate and Tenofovir Alafenamide for Preventing Vertical Transmission of Hepatitis B.

BACKGROUND: Mother-to-child transmission (MTCT) of hepatitis B virus may occur in highly viremic mothers despite the infants receiving appropriate immunoprophylaxis. We aimed to review tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) data for preventing MTCT. METHODS AND DATA SELECTION: We performed a systematic review between January 1, 2015 and December 31, 2021 on PUBMED, EMBASE, Cochrane, CNKI, and Wanfang databases. Data was extracted from randomized controlled trials or cohort studies in English or Chinese. The outcomes of interest included the efficacy and safety of TDF versus TAF or TDF/TAF versus placebo for preventing MTCT (PROSPERO registration: CRD42021256656). RESULTS: Data from forty-three studies (13 randomized controlled trials, 30 nonrandomized studies) were included in the review. All infants in the studies received appropriate immunoprophylaxis. Among 3656 highly viremic mothers treated with TDF, hepatitis B virus DNA suppression to the levels <200,000 IU/mL at delivery was achieved in 34% to 100% of mothers. MTCT rates were 0 to 5% and 2 to 83% in mothers treated with TDF and in those who received no treatment, respectively. Congenital malformation rates were 0 to 2.1% in the TDF groups, which did not differ from the nontreated groups. Similar findings were reported in 4 studies that enrolled 326 mothers for maternal TAF therapy, resulting in 0% of MTCT and 0% infant malformation. All studies observed that TDF or TAF maternal therapy reduced MTCT rates significantly without safety concerns when compared with untreated groups, except for 1 RCT that failed the therapeutic endpoint. CONCLUSIONS: TDF is well established for preventing MTCT in highly viremic mothers, whereas TAF may become an option as data emerges.

Incidence and predictors of elevated postpartum alanine aminotransferase in chronic hepatitis B mothers: a prospective study protocol.

BACKGROUND: The majority of HBeAg-positive mothers with chronic hepatitis B have high levels of viremia and inactive disease with normal alanine aminotransferase (ALT) during pregnancy. In addition, postpartum disease activation and ALT flare have been reported in the range of 15 - 35%. However, the current International Association Guidelines have not provided clear recommendations and a risk-stratified monitoring schedule. Furthermore, data are lacking on the definition of normal ALT in the postpartum period in mothers with chronic hepatitis B. The clinical features and ALT flare patterns in HBeAg-positive mothers versus HBeAg-negative mothers are not fully explored. Thus, we design a cohort study to investigate the aforementioned area and generate data to assist healthcare providers in better managing mothers with hepatitis B. We aim to assess the frequency of postpartum ALT flares and predictors for such events. METHOD: This study is a single-center and prospective cohort study (n = 360) that consists of two groups of patients including HBsAg-positive mothers (n = 120) and healthy mothers without HBV infection (n = 240). In HBeAg-positive mothers, antiviral therapy during late pregnancy is permitted to prevent Mother-to-child transmission (MTCT) but discontinued at delivery if there is no further indication for the treatment. Mothers are enrolled at the gestational weeks of 12-24. After delivery, both mothers and their infants will be followed up until postpartum week 24. Clinical and laboratory data are collected every 4 weeks during the study except there are no follow-up visits at the postpartum weeks 16 and 20. The primary objective is the proportion of patients with postpartum ALT flares. The secondary objectives are independent risk factors during pregnancy for predicting postpartum ALT flares and the normal range of postpartum ALT levels in healthy mothers. DISCUSSION: The current study focuses on the incidence of postpartum ALT flares in mothers with chronic hepatitis B including subgroup analysis based on HBeAg status. The data will have several clinical implications, such as providing evidence for an appropriate monitoring schedule in CHB mothers after delivery. Further analyses on predictors of such events may assist clinicians in identifying mothers who might develop severe postpartum ALT flares. The data generated from healthy mothers have the potential to identify the patterns of ALT changes during pregnancy and postpartum, so we can gain a better understanding of the normal range of ALT in this subpopulation. TRIAL REGISTRATION NUMBER AT THE CHINESE CLINICAL TRIAL REGISTRY: ChiCTR2200061130.

Diagnosis and Management of Hepatitis Delta Virus Infection.

Hepatitis D virus (HDV) depends on hepatitis B virus (HBV) to enter and exit hepatocytes and to replicate. Despite this dependency, HDV can cause severe liver disease. HDV accelerates liver fibrosis, increases the risk of hepatocellular carcinoma, and hastens hepatic decompensation compared to chronic HBV monoinfection. The Chronic Liver Disease Foundation (CLDF) formed an expert panel to publish updated guidelines on the testing, diagnosis, and management of hepatitis delta virus. The panel group performed network data review on the transmission, epidemiology, natural history, and disease sequelae of acute and chronic HDV infection. Based on current available evidence, we provide recommendations for screening, testing, diagnosis, and treatment of hepatitis D infection and review upcoming novel agents that may expand treatment options. The CLDF recommends universal HDV screening for all patients who are Hepatitis B surface antigen-positive. Initial screening should be with an assay to detect antibodies generated against HDV (anti-HDV). Patients who are positive for anti-HDV IgG antibodies should then undergo quantitative HDV RNA testing. We also provide an algorithm that describes CLDF recommendations on the screening, diagnosis, testing, and initial management of Hepatitis D infection.

Long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil in China.

OBJECTIVE: The physical and neuromental development of infants remains uncertain after fetal exposure to tenofovir disoproxil fumarate (TDF) for the prevention of mother-to-child transmission of HBV. We aimed to investigate the safety of TDF therapy during the third trimester of pregnancy. DESIGN: Infants from a previous randomised controlled trial were recruited for our long-term follow-up (LTFU) study. Mothers with chronic hepatitis B were randomised to receive TDF therapy or no treatment during the third trimester. Infants' physical growth or malformation, bone mineral density (BMD) and neurodevelopment, as assessed using Bayley-III assessment, were examined at 192 weeks of age. RESULTS: Of 180 eligible infants, 176/180 (98%) were enrolled and 145/176 (82%) completed the LTFU (control group: 75; TDF-treated group: 70). In the TDF-treated group, the mean duration of fetal exposure to TDF was 8.57±0.53 weeks. Congenital malformation rates were similar between the two groups at week 192. The mean body weight of boys in the control and TDF-treated groups was significantly higher (19.84±3.46 kg vs. 18.47±2.34 kg; p=0.03) and within the normal range (18.48±2.35 kg vs. 17.80±2.50 kg; p=0.07), respectively, when compared with the national standard. Other prespecified outcomes (head circumference, height, BMD, and cognitive, motor, social-emotional, and adaptive behaviour measurements) were all comparable between the groups. CONCLUSION: Infants with fetal exposure to TDF had normal physical growth, BMD and neurodevelopment at week 192. Our findings provide evidence on the long-term safety of infants after fetal exposure to maternal TDF therapy for preventing hepatitis B transmission. TRIAL REGISTRATION NUMBER: NCT01488526.

RIPK1 Expression Associates With Inflammation in Early Atherosclerosis in Humans and Can Be Therapeutically Silenced to Reduce NF-κB Activation and Atherogenesis in Mice.

BACKGROUND: Chronic activation of the innate immune system drives inflammation and contributes directly to atherosclerosis. We previously showed that macrophages in the atherogenic plaque undergo RIPK3 (receptor-interacting serine/threonine-protein kinase 3)-MLKL (mixed lineage kinase domain-like protein)-dependent programmed necroptosis in response to sterile ligands such as oxidized low-density lipoprotein and damage-associated molecular patterns and that necroptosis is active in advanced atherosclerotic plaques. Upstream of the RIPK3-MLKL necroptotic machinery lies RIPK1 (receptor-interacting serine/threonine-protein kinase 1), which acts as a master switch that controls whether the cell undergoes NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells)-dependent inflammation, caspase-dependent apoptosis, or necroptosis in response to extracellular stimuli. We therefore set out to investigate the role of RIPK1 in the development of atherosclerosis, which is driven largely by NF-κB-dependent inflammation at early stages. We hypothesize that, unlike RIPK3 and MLKL, RIPK1 primarily drives NF-κB-dependent inflammation in early atherogenic lesions, and knocking down RIPK1 will reduce inflammatory cell activation and protect against the progression of atherosclerosis. METHODS: We examined expression of RIPK1 protein and mRNA in both human and mouse atherosclerotic lesions, and used loss-of-function approaches in vitro in macrophages and endothelial cells to measure inflammatory responses. We administered weekly injections of RIPK1 antisense oligonucleotides to Apoe-/- mice fed a cholesterol-rich (Western) diet for 8 weeks. RESULTS: We find that RIPK1 expression is abundant in early-stage atherosclerotic lesions in both humans and mice. Treatment with RIPK1 antisense oligonucleotides led to a reduction in aortic sinus and en face lesion areas (47.2% or 58.8% decrease relative to control, P<0.01) and plasma inflammatory cytokines (IL-1α [interleukin 1α], IL-17A [interleukin 17A], P<0.05) in comparison with controls. RIPK1 knockdown in macrophages decreased inflammatory genes (NF-κB, TNFα [tumor necrosis factor α], IL-1α) and in vivo lipopolysaccharide- and atherogenic diet-induced NF-κB activation. In endothelial cells, knockdown of RIPK1 prevented NF-κB translocation to the nucleus in response to TNFα, where accordingly there was a reduction in gene expression of IL1B, E-selectin, and monocyte attachment. CONCLUSIONS: We identify RIPK1 as a central driver of inflammation in atherosclerosis by its ability to activate the NF-κB pathway and promote inflammatory cytokine release. Given the high levels of RIPK1 expression in human atherosclerotic lesions, our study suggests RIPK1 as a future therapeutic target to reduce residual inflammation in patients at high risk of coronary artery disease.

Validation of Baveno VII criteria for recompensation in entecavir-treated patients with hepatitis B-related decompensated cirrhosis.

BACKGROUND & AIMS: Antiviral therapy improves the clinical outcomes of patients with chronic hepatitis B (CHB), including those with cirrhosis. In the present study, we validated the Baveno VII definition of recompensation and explored the criteria for stable improvement of liver function tests in entecavir-treated patients with CHB-related decompensated cirrhosis. METHODS: In this multicentre prospective study, patients with decompensated (ascites) CHB-related cirrhosis were enrolled and treated with entecavir for 120 weeks. Patients were followed up for clinical events, viral and biochemical tests, and ultrasonography every 6 months. The recompensation rate per Baveno VII criteria was calculated. Multivariate regression models were used to identify the predictors of recompensation. Finally, the criteria for stable improvement of liver function tests were explored. RESULTS: Of the 320 recruited patients, 283 completed the 120-week study, with 261/283 (92.2%) achieving HBV DNA levels <20 IU/ml and 171/283 (60.4%) achieving resolution of ascites, encephalopathy, and absence of recurrent variceal bleeding for at least 12 months. We identified model for end-stage liver disease <10 and/or liver function tests within Child-Pugh Class A (albumin >35 g/L, international normalised ratio <1.50 and total bilirubin <34 µmol/L) as the criteria for stable improvement of liver function tests. Accordingly, 56.2% (159/283) of patients fulfilled the Baveno VII definition of recompensation with a stable improvement of liver function tests defined by the current study. CONCLUSIONS: Our study defined the criteria for a stable improvement of liver function tests required by the Baveno VII definition of recompensation in patients with CHB-related decompensated cirrhosis on antiviral therapy. The criteria derived from this multicentre prospective study warrant further validation in patients with cirrhosis of other aetiologies. LAY SUMMARY: Decompensation of cirrhosis marks the point at which the liver is no longer able to function normally (and symptoms become apparent). Recently the idea of recompensation was proposed for individuals who may experience an improvement in liver function if the underlying cause of their liver disease is addressed (e.g. antivirals for viral cirrhosis). Herein, we show that over 50% of patients with hepatitis B-related decompensated cirrhosis treated with antivirals could recompensate and we propose laboratory criteria which could be used to define recompensation.

Transcriptome-wide association study of coronary artery disease identifies novel susceptibility genes.

The majority of risk loci identified by genome-wide association studies (GWAS) are in non-coding regions, hampering their functional interpretation. Instead, transcriptome-wide association studies (TWAS) identify gene-trait associations, which can be used to prioritize candidate genes in disease-relevant tissue(s). Here, we aimed to systematically identify susceptibility genes for coronary artery disease (CAD) by TWAS. We trained prediction models of nine CAD-relevant tissues using EpiXcan based on two genetics-of-gene-expression panels, the Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task (STARNET) and the Genotype-Tissue Expression (GTEx). Based on these prediction models, we imputed gene expression of respective tissues from individual-level genotype data on 37,997 CAD cases and 42,854 controls for the subsequent gene-trait association analysis. Transcriptome-wide significant association (i.e. P < 3.85e-6) was observed for 114 genes. Of these, 96 resided within previously identified GWAS risk loci and 18 were novel. Stepwise analyses were performed to study their plausibility, biological function, and pathogenicity in CAD, including analyses for colocalization, damaging mutations, pathway enrichment, phenome-wide associations with human data and expression-traits correlations using mouse data. Finally, CRISPR/Cas9-based gene knockdown of two newly identified TWAS genes, RGS19 and KPTN, in a human hepatocyte cell line resulted in reduced secretion of APOB100 and lipids in the cell culture medium. Our CAD TWAS work (i) prioritized candidate causal genes at known GWAS loci, (ii) identified 18 novel genes to be associated with CAD, and iii) suggested potential tissues and pathways of action for these TWAS CAD genes.

Genetic regulation of liver lipids in a mouse model of insulin resistance and hepatic steatosis.

To elucidate the contributions of specific lipid species to metabolic traits, we integrated global hepatic lipid data with other omics measures and genetic data from a cohort of about 100 diverse inbred strains of mice fed a high-fat/high-sucrose diet for 8 weeks. Association mapping, correlation, structure analyses, and network modeling revealed pathways and genes underlying these interactions. In particular, our studies lead to the identification of Ifi203 and Map2k6 as regulators of hepatic phosphatidylcholine homeostasis and triacylglycerol accumulation, respectively. Our analyses highlight mechanisms for how genetic variation in hepatic lipidome can be linked to physiological and molecular phenotypes, such as microbiota composition.

The role of gut microbiota in hepatitis B disease progression and treatment.

Current therapeutic interventions can only suppress hepatitis B virus (HBV) replication or reduce complications without a cure. Therefore, further development of new treatment methods is critical for the global eradication of HBV. Accumulating evidence suggests that the liver and gut share an interconnected relationship referred to as the 'Gut-Liver Axis', where exchanges happen bi-directionally. The gut itself is the host to a unique microbiota profile which has metabolic, immunological, neurological and nutritional functions. Gut microbiota is not only constantly intersecting with the liver but also associated with hepatic injury when dysbiosis occurs. In recent years, there has been increased interest in gut microbiota and its implications on liver disease treatment. Progress has been made in understanding the complex relationship between chronic hepatitis B (CHB) and gut microbiota. New investigative techniques such as colony-free sequencing enabled new perspectives into this field. Mouse models and human studies revealed that HBV infection is associated with significant alteration of gut microbiota, which differ depending on the stage of CHB disease progression. Different mechanisms of the hepatic injury from gut microbiota dysbiosis have also been proposed based on findings of increased intestinal permeability to toxins, disruption of normal bacterial metabolism, and colonization of the gut by oral microbiota. New treatment methods targeting gut microbiota in CHB, such as probiotics and faecal microbiota transplant, have also gained promising results in recent years. The current review recapitulated the most recent investigations into the relationship between gut microbiota and CHB to provide research directions towards the new therapeutic target of CHB.

Genome-wide analysis identifies novel susceptibility loci for myocardial infarction.

AIMS: While most patients with myocardial infarction (MI) have underlying coronary atherosclerosis, not all patients with coronary artery disease (CAD) develop MI. We sought to address the hypothesis that some of the genetic factors which establish atherosclerosis may be distinct from those that predispose to vulnerable plaques and thrombus formation. METHODS AND RESULTS: We carried out a genome-wide association study for MI in the UK Biobank (n∼472 000), followed by a meta-analysis with summary statistics from the CARDIoGRAMplusC4D Consortium (n∼167 000). Multiple independent replication analyses and functional approaches were used to prioritize loci and evaluate positional candidate genes. Eight novel regions were identified for MI at the genome wide significance level, of which effect sizes at six loci were more robust for MI than for CAD without the presence of MI. Confirmatory evidence for association of a locus on chromosome 1p21.3 harbouring choline-like transporter 3 (SLC44A3) with MI in the context of CAD, but not with coronary atherosclerosis itself, was obtained in Biobank Japan (n∼165 000) and 16 independent angiography-based cohorts (n∼27 000). Follow-up analyses did not reveal association of the SLC44A3 locus with CAD risk factors, biomarkers of coagulation, other thrombotic diseases, or plasma levels of a broad array of metabolites, including choline, trimethylamine N-oxide, and betaine. However, aortic expression of SLC44A3 was increased in carriers of the MI risk allele at chromosome 1p21.3, increased in ischaemic (vs. non-diseased) coronary arteries, up-regulated in human aortic endothelial cells treated with interleukin-1ß (vs. vehicle), and associated with smooth muscle cell migration in vitro. CONCLUSIONS: A large-scale analysis comprising ∼831 000 subjects revealed novel genetic determinants of MI and implicated SLC44A3 in the pathophysiology of vulnerable plaques.

Colocalization of GWAS and eQTL signals at loci with multiple signals identifies additional candidate genes for body fat distribution.

Integration of genome-wide association study (GWAS) signals with expression quantitative trait loci (eQTL) studies enables identification of candidate genes. However, evaluating whether nearby signals may share causal variants, termed colocalization, is affected by the presence of allelic heterogeneity, different variants at the same locus impacting the same phenotype. We previously identified eQTL in subcutaneous adipose tissue from 770 participants in the Metabolic Syndrome in Men (METSIM) study and detected 15 eQTL signals that colocalized with GWAS signals for waist-hip ratio adjusted for body mass index (WHRadjBMI) from the Genetic Investigation of Anthropometric Traits consortium. Here, we reevaluated evidence of colocalization using two approaches, conditional analysis and the Bayesian test COLOC, and show that providing COLOC with approximate conditional summary statistics at multi-signal GWAS loci can reconcile disagreements in colocalization classification between the two tests. Next, we performed conditional analysis on the METSIM subcutaneous adipose tissue data to identify conditionally distinct or secondary eQTL signals. We used the two approaches to test for colocalization with WHRadjBMI GWAS signals and evaluated the differences in colocalization classification between the two tests. Through these analyses, we identified four GWAS signals colocalized with secondary eQTL signals for FAM13A, SSR3, GRB14 and FMO1. Thus, at loci with multiple eQTL and/or GWAS signals, analyzing each signal independently enabled additional candidate genes to be identified.