Browsing by Subject "FAF2"

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    Genome-wide Association Study and Meta-analysis on Alcohol-Associated Liver Cirrhosis Identifies Genetic Risk Factors
    (Wiley, 2021-05) Schwantes-An, Tae-Hwi; Darlay, Rebecca; Mathurin, Philippe; Masson, Steven; Liangpunsakul, Suthat; Mueller, Sebastian; Aithal, Guruprasad P.; Eyer, Florian; Gleeson, Dermot; Thompson, Andrew; Muellhaupt, Beat; Stickel, Felix; Soyka, Michael; Goldman, David; Liang, Tiebing; Lumeng, Lawrence; Pirmohamed, Munir; Nalpas, Bertrand; Jacquet, Jean-Marc; Moirand, Romain; Nahon, Pierre; Naveau, Sylvie; Perney, Pascal; Botwin, Greg; Haber, Paul S.; Seitz, Helmut K.; Day, Christopher P.; Foroud, Tatiana M.; Daly, Ann K.; Cordell, Heather J.; Whitfield, John B.; Morgan, Timothy R.; Seth, Devanshi; GenomALC Consortium; Medical and Molecular Genetics, School of Medicine
    Background and Aims Only a minority of heavy drinkers progress to alcohol-associated cirrhosis (ALC). The aim of this study was to identify common genetic variants that underlie risk for ALC. Approach and Results We analyzed data from 1,128 subjects of European ancestry with ALC and 614 heavy-drinking subjects without known liver disease from Australia, the United States, the United Kingdom, and three countries in Europe. A genome-wide association study (GWAS) was performed, adjusting for principal components and clinical covariates (alcohol use, age, sex, body mass index, and diabetes). We validated our GWAS findings using UK Biobank. We then performed a meta-analysis combining data from our study, the UK Biobank, and a previously published GWAS. Our GWAS found genome-wide significant risk association of rs738409 in patatin-like phospholipase domain containing 3 (PNPLA3) (odds ratio [OR] = 2.19 [G allele], P = 4.93 × 10−17) and rs4607179 near HSD17B13 (OR = 0.57 [C allele], P = 1.09 × 10−10) with ALC. Conditional analysis accounting for the PNPLA3 and HSD17B13 loci identified a protective association at rs374702773 in Fas-associated factor family member 2 (FAF2) (OR = 0.61 [del(T) allele], P = 2.56 × 10−8) for ALC. This association was replicated in the UK Biobank using conditional analysis (OR = 0.79, P = 0.001). Meta-analysis (without conditioning) confirmed genome-wide significance for the identified FAF2 locus as well as PNPLA3 and HSD17B13. Two other previously known loci (SERPINA1 and SUGP1/TM6SF2) were also genome-wide significant in the meta-analysis. GeneOntology pathway analysis identified lipid droplets as the target for several identified genes. In conclusion, our GWAS identified a locus at FAF2 associated with reduced risk of ALC among heavy drinkers. Like the PNPLA3 and HSD17B13 gene products, the FAF2 product has been localized to fat droplets in hepatocytes. Conclusions Our genetic findings implicate lipid droplets in the biological pathway(s) underlying ALC.
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    Silencing FAF2 mitigates alcohol-induced hepatic steatosis by modulating lipolysis and PCSK9 pathway
    (Wolters Kluwer, 2025-02-19) Huda, Nazmul; Kusumanchi, Praveen; Jiang, Yanchao; Gao, Hui; Thoudam, Themis; Zeng, Ge; Skill, Nicholas J.; Sun, Zhaoli; Liangpunsakul, Suthat; Ma, Jing; Yang, Zhihong; Medicine, School of Medicine
    Background: Chronic alcohol consumption leads to lipid accumulation, oxidative stress, cellular damage, and inflammation in the liver, collectively referred to as alcohol-associated liver disease (ALD). FAF2/UBXD8/ETEA (Fas-associated factor 2) is a ubiquitin ligase adaptor protein that plays a crucial role in the ubiquitin-mediated degradation of misfolded proteins in the endoplasmic reticulum. A recent genome-wide association study indicated an association between FAF2 and ALD; however, the exact contribution of FAF2 to ALD pathogenesis remains unclear. Methods: FAF2 was knocked down using AAV-delivered shRNA in C57/BL6 mice. Mice were subjected to a chronic-plus-single binge ethanol feeding (NIAAA) model. Nine hours after gavage, liver, blood, and other organs of interest were collected for gene expression and biochemical analyses. Results: We first observed a significant elevation in hepatic FAF2 protein expression in individuals with ALD and in mice subjected to an ethanol-binge model. Interestingly, knocking down FAF2 in the liver using adeno-associated virus serotype 8-delivered short hairpin RNA conferred a protective effect against alcohol-induced liver steatosis in ethanol-binged mice. Transcriptomic analysis revealed that differentially expressed genes were enriched in multiple lipid metabolism regulation pathways. Further analysis of transcription factors regulating these differentially expressed genes suggested potential regulation by SREBP1. Several SREBP1 target genes, including Fasn, Scd1, Lpin1, and Pcsk9 (proprotein convertase subtilisin/kexin type 9), were dysregulated in the livers of ethanol-fed FAF2 knockdown mice. Additionally, Pcsk9 could be regulated through the FOXO3-SIRT6 pathway in the livers of ethanol-fed FAF2 knockdown mice, leading to increased liver low-density lipoprotein receptor expression and reduced plasma LDL cholesterol levels. Furthermore, FAF2 knockdown in mouse liver enhanced adipose triglyceride lipase lipolytic activity by upregulating the adipose triglyceride lipase activator, comparative gene identification-58, and downregulating the adipose triglyceridelipase transport inhibitor, Elmod2, contributing to the alleviation of liver steatosis. Conclusions: Our study uncovers a novel mechanism involving FAF2 in the pathogenesis of ALD.