Jiao, J;Sanchez, J;Saldarriaga, O;Solis, L;Tweardy, D;Maru, D;Stevenson, H;Beretta, L;
| DOI: 10.1016/j.jhepr.2022.100628
Background & Aims The prevalence of non-alcoholic fatty liver disease (NAFLD) and its severe form, non-alcoholic steatohepatitis (NASH), is increasing. Subjects with NASH often develop liver fibrosis and advanced liver fibrosis is the main determinant of mortality in NASH patients. We and others have reported that STAT3 contributes to liver fibrosis and hepatocellular carcinoma in mice. Methods Here, we explored whether STAT3 activation in hepatocytes and in non-hepatocytes areas, measured by phospho-STAT3 (pSTAT3), is associated with liver fibrosis progression in 133 patients with NAFLD. We further characterized the molecular and cellular determinants of STAT3 activation by integrating spatial distribution and transcriptomic changes in fibrotic NAFLD liver. Results pSTAT3 scores in non-hepatocytes areas progressively increased with fibrosis severity (r=0.53, p
Hepatology (Baltimore, Md.)
Nejak-Bowen, K;Monga, SP;
PMID: 37246413 | DOI: 10.1097/HEP.0000000000000495
Wnt-β-catenin signaling has emerged as an important regulatory pathway in liver, playing key roles in zonation and mediating contextual hepatobiliary repair after injuries. In this review, we will address the major advances in understanding the role of Wnt signaling in hepatic zonation, regeneration, and cholestasis-induced injury. We will also touch upon some important unanswered questions, and discuss the relevance of modulating the pathway to provide therapies for complex liver pathologies that remain a continued unmet clinical need.
Hepatology (Baltimore, Md.)
Niknejad, N;Fox, D;Burwinkel, JL;Zarrin-Khameh, N;Cho, S;Soriano, A;Cast, AE;Lopez, MF;Huppert, KA;Rigo, F;Huppert, SS;Jafar-Nejad, P;Jafar-Nejad, H;
PMID: 37021797 | DOI: 10.1097/HEP.0000000000000380
Paucity of intrahepatic bile ducts is caused by various etiologies and often leads to cholestatic liver disease. For example, in patients with Alagille syndrome (ALGS), which is a genetic disease primarily caused by mutations in JAG1, bile duct paucity often results in severe cholestasis and liver damage. However, no mechanism-based therapy exists to restore the biliary system in ALGS or other diseases associated with bile duct paucity. Based on previous genetic observations, we investigate whether postnatal knockdown of the glycosyltransferase gene Poglut1 can improve the ALGS liver phenotypes in several mouse models generated by removing one copy of Jag1 in the germline with or without reducing the gene dosage of Sox9 in the liver.Using an antisense oligonucleotide (ASO) established in this study, we show that reducing Poglut1 levels in postnatal livers of ALGS mouse models with moderate to profound biliary abnormalities can significantly improve bile duct development and biliary tree formation. Importantly, ASO injections prevent liver damage in these models without adverse effects. Furthermore, ASO-mediated Poglut1 knockdown improves biliary tree formation in a different mouse model with no Jag1 mutations. Cell-based signaling assays indicate that reducing POGLUT1 levels or mutating POGLUT1 modification sites on JAG1 increase JAG1 protein level and JAG1-mediated signaling, suggesting a likely mechanism for the observed in vivo rescue.Our preclinical studies establish ASO-mediated POGLUT1 knockdown as a potential therapeutic strategy for ALGS liver disease and possibly other diseases associated with BD paucity.
Ding, C;Yu, Z;Sefik, E;Zhou, J;Kaffe, E;Wang, G;Li, B;Flavell, RA;Hu, W;Ye, Y;Li, HB;
PMID: 37277640 | DOI: 10.1038/s43587-023-00428-8
Regulatory T (Treg) cells modulate several aging-related liver diseases. However, the molecular mechanisms regulating Treg function in this context are unknown. Here we identified a long noncoding RNA, Altre (aging liver Treg-expressed non-protein-coding RNA), which was specifically expressed in the nucleus of Treg cells and increased with aging. Treg-specific deletion of Altre did not affect Treg homeostasis and function in young mice but caused Treg metabolic dysfunction, inflammatory liver microenvironment, liver fibrosis and liver cancer in aged mice. Depletion of Altre reduced Treg mitochondrial integrity and respiratory capacity, and induced reactive oxygen species accumulation, thus increasing intrahepatic Treg apoptosis in aged mice. Moreover, lipidomic analysis identified a specific lipid species driving Treg aging and apoptosis in the aging liver microenvironment. Mechanistically, Altre interacts with Yin Yang 1 to orchestrate its occupation on chromatin, thereby regulating the expression of a group of mitochondrial genes, and maintaining optimal mitochondrial function and Treg fitness in the liver of aged mice. In conclusion, the Treg-specific nuclear long noncoding RNA Altre maintains the immune-metabolic homeostasis of the aged liver through Yin Yang 1-regulated optimal mitochondrial function and the Treg-sustained liver immune microenvironment. Thus, Altre is a potential therapeutic target for the treatment of liver diseases affecting older adults.
Li, X;Li, Y;Xiao, J;Wang, H;Guo, Y;Mao, X;Shi, P;Hou, Y;Zhang, X;Zhao, N;Zheng, M;He, Y;Ding, J;Tan, Y;Liao, M;Li, L;Peng, Y;Li, X;Pan, Q;Xie, Q;Li, Q;Li, J;Li, Y;Chen, Z;Huang, Y;Assis, DN;Cai, SY;Boyer, JL;Huang, X;Tang, CE;Liu, X;Peng, S;Chai, J;
PMID: 36759512 | DOI: 10.1038/s41467-022-34606-w
Cholangiocytes play a crucial role in bile formation. Cholangiocyte injury causes cholestasis, including primary biliary cholangitis (PBC). However, the etiology of PBC remains unclear despite being characterized as an autoimmune disease. Using single-cell RNA sequencing (scRNA-seq), fluorescence-activated-cell-sorting, multiplex immunofluorescence (IF) and RNAscope analyses, we identified unique DUOX2+ACE2+ small cholangiocytes in human and mouse livers. Their selective decrease in PBC patients was associated with the severity of disease. Moreover, proteomics, scRNA-seq, and qPCR analyses indicated that polymeric immunoglobulin receptor (pIgR) was highly expressed in DUOX2+ACE2+ cholangiocytes. Serum anti-pIgR autoantibody levels were significantly increased in PBC patients, regardless of positive and negative AMA-M2. Spatial transcriptomics and multiplex IF revealed that CD27+ memory B and plasma cells accumulated in the hepatic portal tracts of PBC patients. Collectively, DUOX2+ACE2+ small cholangiocytes are pathogenic targets in PBC, and preservation of DUOX2+ACE2+ cholangiocytes and targeting anti-pIgR autoantibodies may be valuable strategies for therapeutic interventions in PBC.
Short, C;Zhong, A;Xu, J;Mahdi, E;Glazier, A;Malkoff, N;
| DOI: 10.1097/HEP.0000000000000026
The experimental mouse model of BA mediated by perinatal rhesus rotavirus (RRV) infection resulted in increased co-expression of _Fn14_ in _Prom1_-expressing HPCs within regions of ductular reactions. FN14 antagonist L524-0366 decreased ductular reactions, biliary fibrosis and periportal fibroblast activation in RRV injury. L524-0366 inhibition also demonstrated loss of downstream non-canonical NF-kB signaling expression in RRV injury. Murine HPC organoids demonstrated accelerated organoid growth and proliferation when treated with recombinant TWEAK. Increased organoid proliferation with recombinant TWEAK was lost when also treated with L524-0366. Analysis of a large publicly available RNA-seq database of BA and normal control patients revealed significant increases in expression of _PROM1_, _FN14_, and genes downstream of TNF signaling and non-canonical NF-kB signaling pathways in BA infants. Infants who failed to achieve bile drainage after hepatoportoenterostomy had higher relative levels of _FN14_ expression.
Larsen, F;Hansen, D;Terkelsen, M;Bendixen, S;Avolio, F;Wernberg, C;Lauridsen, M;Grønkjaer, L;Jacobsen, B;Klinggaard, E;Mandrup, S;Di Caterino, T;Siersbæk, M;Chandran, V;Graversen, J;Krag, A;Grøntved, L;Ravnskjaer, K;
| DOI: 10.1016/j.jhepr.2022.100615
Background & Aims Non-alcoholic fatty liver disease (NAFLD) and its progressive form, non-alcoholic steatohepatitis (NASH), are the hepatic manifestations of metabolic syndrome. Histological assessment of liver biopsies is the gold standard for diagnosis of NASH. A Liver biopsy is resource heavy, can lead to complications such as bleeding, and does not fully capture tissue heterogeneity of the fibrotic liver. Therefore, non-invasive biomarkers that can reflect an integrated state of the liver are highly needed to improve diagnosis and sampling bias. Hepatic stellate cells (HSCs) are central in development of hepatic fibrosis, a hallmark of NASH. Secreted HSC-specific proteins may, therefore, reflect disease state in the NASH liver and serve as non-invasive diagnostic biomarkers. Methods We performed RNA-sequencing on liver biopsies from a histological characterised cohort of obese patients (n = 30, body mass index > 35 kg/m2) to identify and evaluate HSC-specific genes encoding secreted proteins. Bioinformatics was used to identify potential biomarkers and their expression at single-cell resolution. We validated our findings by single-molecule fluorescence in situ hybridisation (smFISH) and ELISA to detect mRNA in liver tissue and protein levels in plasma, respectively. Results Hepatic expression of SPARC-related modular calcium-binding protein 2 (SMOC2) was increased in NASH compared no-NAFLD (p.adj < 0.001). Single-cell RNA-sequencing data indicated SMOC2 expression by HSCs, which was validated using smFISH. Finally, plasma SMOC2 was elevated in NASH compared to no-NAFLD (p < 0.001) with a predictive accuracy of AUROC 0.88. Conclusions We propose increased SMOC2 in plasma reflects HSC activation, a key cellular event associated with NASH progression, and may serve as a non-invasive biomarker of NASH.
Carbonaro, M;Lee, J;Pefanis, E;Desclaux, M;Wang, K;Pennington, A;Huang, H;Mujica, A;Rojas, J;Ally, R;Kennedy, D;Brown, M;Rogulin, V;Moller-Tank, S;Sabin, L;Zambrowicz, B;Thurston, G;Li, Z;
PMID: 35982097 | DOI: 10.1038/s41598-022-18119-6
Humanized liver rodent models, in which the host liver parenchyma is repopulated by human hepatocytes, have been increasingly used for drug development and disease research. Unlike the leading humanized liver mouse model in which Fumarylacetoacetate Hydrolase (Fah), Recombination Activating Gene (Rag)-2 and Interleukin-2 Receptor Gamma (Il2rg) genes were inactivated simultaneously, generation of similar recipient rats has been challenging. Here, using Velocigene and 1-cell-embryo-targeting technologies, we generated a rat model deficient in Fah, Rag1/2 and Il2rg genes, similar to humanized liver mice. These rats were efficiently engrafted with Fah-expressing hepatocytes from rat, mouse and human. Humanized liver rats expressed human albumin and complement proteins in serum and showed a normal liver zonation pattern. Further, approaches were developed for gene delivery through viral transduction of human hepatocytes either in vivo, or in vitro prior to engraftment, providing a novel platform to study liver disease and hepatocyte-targeted therapies.
Hepatology (Baltimore, Md.)
Song, L;Wang, L;Hou, Y;Zhou, J;Chen, C;Ye, X;Dong, W;Gao, H;Liu, Y;Qiao, G;Pan, T;Chen, Q;Cao, Y;Hu, F;Rao, Z;Chen, Y;Han, Y;Zheng, M;Luo, Y;Li, X;Chen, Y;Huang, Z;
PMID: 35152446 | DOI: 10.1002/hep.32404
NAFLD represents an increasing health problem in association with obesity and diabetes with no effective pharmacotherapies. Growing evidence suggests that several FGFs play important roles in diverse aspects of liver pathophysiology. Here, we report a previously unappreciated role of FGF4 in the liver.Expression of hepatic FGF4 is inversely associated with NAFLD pathological grades in both human patients and mouse models. Loss of hepatic Fgf4 aggravates hepatic steatosis and liver damage resulted from an obesogenic high-fat diet. By contrast, pharmacological administration of recombinant FGF4 mitigates hepatic steatosis, inflammation, liver damage, and fibrogenic markers in mouse livers induced to develop NAFLD and NASH under dietary challenges. Such beneficial effects of FGF4 are mediated predominantly by activating hepatic FGF receptor (FGFR) 4, which activates a downstream Ca2+ -Ca2+ /calmodulin-dependent protein kinase kinase beta-dependent AMP-activated protein kinase (AMPK)-Caspase 6 signal axis, leading to enhanced fatty acid oxidation, reduced hepatocellular apoptosis, and mitigation of liver damage.Our study identifies FGF4 as a stress-responsive regulator of liver pathophysiology that acts through an FGFR4-AMPK-Caspase 6 signal pathway, shedding light on strategies for treating NAFLD and associated liver pathologies.
Zeitschrift für Gastroenterologie
Qian, Y;Evert, K;Itzel, T;Albin, JE;
| DOI: 10.1055/s-0042-1754738
Background and aims Graft-versus-host-disease (GvHD) is a common complication following allogeneic hematopoietic stem cell transplantation (aHCT) that typically manifests as injury response to the skin, gastrointestinal mucosa and liver. In liver, late onset acute and chronic liver GvHD are more similar to an autoimmune reaction. The identification of valid GvHD biomarker is still an unmet clinical need. In our study, we therefore aimed to identify gene expression patterns, which could be used as potential indicators for the outcome of aHCTs with regard to acute or chronic GvHD. For this purpose, we expect to uncover similar and distinct gene signatures of GvHD in comparison to non-diseased liver tissues and detect potential candidates giving information about the outcome after aHCT. Method Microarray analyses from FFPE samples of patients were performed, and the following criteria were applied: fold change> [1] and a p- value
Science translational medicine
Xiao, Y;Batmanov, K;Hu, W;Zhu, K;Tom, AY;Guan, D;Jiang, C;Cheng, L;McCright, SJ;Yang, EC;Lanza, MR;Liu, Y;Hill, DA;Lazar, MA;
PMID: 36753562 | DOI: 10.1126/scitranslmed.adc9653
Current therapeutic strategies for treating nonalcoholic steatohepatitis (NASH) have failed to alleviate liver fibrosis, which is a devastating feature leading to hepatic dysfunction. Here, we integrated single-nucleus transcriptomics and epigenomics to characterize all major liver cell types during NASH development in mice and humans. The bifurcation of hepatocyte trajectory with NASH progression was conserved between mice and humans. At the nonalcoholic fatty liver (NAFL) stage, hepatocytes exhibited metabolic adaptation, whereas at the NASH stage, a subset of hepatocytes was enriched for the signatures of cell adhesion and migration, which were mainly demarcated by receptor tyrosine kinase ephrin type B receptor 2 (EphB2). EphB2, acting as a downstream effector of Notch signaling in hepatocytes, was sufficient to induce cell-autonomous inflammation. Knockdown of Ephb2 in hepatocytes ameliorated inflammation and fibrosis in a mouse model of NASH. Thus, EphB2-expressing hepatocytes contribute to NASH progression and may serve as a potential therapeutic target.
Liu, G;Wang, L;Wess, J;Dean, A;
PMID: 36018801 | DOI: 10.1093/nar/gkac707
Enhancers establish proximity with distant target genes to regulate temporospatial gene expression and specify cell identity. Lim domain binding protein 1 (LDB1) is a conserved and widely expressed protein that functions as an enhancer looping factor. Previous studies in erythroid cells and neuronal cells showed that LDB1 forms protein complexes with different transcription factors to regulate cell-specific gene expression. Here, we show that LDB1 regulates expression of liver genes by occupying enhancer elements and cooperating with hepatic transcription factors HNF4A, FOXA1, TCF7 and GATA4. Using the glucose transporter SLC2A2 gene, encoding GLUT2, as an example, we find that LDB1 regulates gene expression by mediating enhancer-promoter interactions. In vivo, we find that LDB1 deficiency in primary mouse hepatocytes dysregulates metabolic gene expression and changes the enhancer landscape. Conditional deletion of LDB1 in adult mouse liver induces glucose intolerance. However, Ldb1 knockout hepatocytes show improved liver pathology under high-fat diet conditions associated with increased expression of genes related to liver fatty acid metabolic processes. Thus, LDB1 is linked to liver metabolic functions under normal and obesogenic conditions.