Project description:The goal of the study was to analyze gene expression profle from the WD patients who underwent liver transplantation for acute or chronic liver failure. Control specimens were obtained from patients who underwent liver resections for other clinical reasons. We used microarrays (Affymetrix) to determine the gene expression profile in WD
Project description:Wilson disease (WD) is an autosomal recessive disease caused by mutations in ATP7B encoding a copper transporter. Consequent copper accumulation results in a variable WD clinical phenotype involving hepatic, neurologic, and psychiatric symptoms, without clear genotype-phenotype correlations. The goal of this study was to analyze alterations in DNA methylation at the whole-genome level in liver and blood from patients with WD to investigate epigenomic alterations associated with WD diagnosis and phenotype. We used whole-genome bisulfite sequencing (WGBS) to examine distinct cohorts of WD subjects to determine whether DNA methylation could differentiate patients from healthy subjects and subjects with other liver diseases and distinguish between different WD phenotypes. WGBS analyses in liver identified 969 hypermethylated and 871 hypomethylated differentially methylated regions (DMRs) specifically identifying patients with WD, including 18 regions with genome-wide significance. WD-specific liver DMRs were associated with genes enriched for functions in folate and lipid metabolism and acute inflammatory response and could differentiate early from advanced fibrosis in WD patients. Functional annotation revealed that WD-hypermethylated liver DMRs were enriched in liver-specific enhancers, flanking active liver promoters, and binding sites of liver developmental transcription factors, including Hepatocyte Nuclear Factor 4 alpha (HNF4A), Retinoid X Receptor alpha (RXRA), Forkhead Box A1 (FOXA1), and FOXA2. DMRs associated with WD progression were also identified, including 15 with genome-wide significance. However, WD DMRs in liver were not related to large-scale changes in proportions of liver cell types. DMRs detected in blood differentiated WD patients from healthy and disease control subjects, and distinguished between patients with hepatic and neurologic WD manifestations. WD phenotype DMRs corresponded to genes enriched for functions in mental deterioration, abnormal B cell physiology, and as members of the polycomb repressive complex 1 (PRC1). 44 DMRs associated with WD phenotype tested in a small validation cohort had a predictive value of 0.9. We identified a disease-mechanism relevant epigenomic signature of WD that reveals new insights into potential biomarkers and treatments for this complex monogenic disease.
Project description:Diagnosis of Wilson disease (WD) can be difficult because of its protean clinical presentation, but early diagnosis is important because effective treatment is available and can prevent disease progression. Using quantitative proteomics, we characterized proteins that are differentially expressed in WD compared to normal liver. Further the expression of MT1M and COX17 were validated using immunohistochemistry. We found diffuse MT immunoreactivity in all liver specimens from patients with WD (n=20), the intensity of the staining was moderate to strong. This staining pattern was distinct from that seen in specimens from the control groups which included diseases that may be in the clinical or histologic differential of WD (steatohepatitis (n=51), chronic viral hepatitis (n=40), autoimmune hepatitis (n=50), chronic biliary tract disease (n=42), and normal liver (n=20)). COX17 immunostain showed no significant difference in expression between the WD and control groups. MT had higher sensitivity than rhodanine for diagnosis of WD. While the quantitative liver copper assays also had high sensitivity, they require more tissue, have a higher cost, have longer turnaround time, and are less widely available than an immunohistochemical stain. We conclude that MT IHC is a sensitive immunohistochemical stain for the diagnosis of Wilson disease that could be widely deployed as a screening tool for liver biopsies in which Wilson disease is in the clinical or histologic differential diagnosis.
Project description:Background & Aims: Wilson disease (WD) is an autosomal recessive disorder that results in excessive hepatic copper causing hepatic steatosis, inflammation, fibrosis, cirrhosis, and liver failure. Previous studies have revealed dysregulation of many FXR metabolic target genes in animal models of WD, including Bsep, the major determinant of bile flow. Approach & Results: We tested the hypothesis that the FXR-cistrome is decreased in Atp7b-/- mice in accord with dysregulated bile acid homeostasis. RNA-Seq and ChIP-Seq analyses of Atp7b-/- and wild-type (WT) mouse livers confirmed that significantly altered transcripts and FXR-binding events overlapped. Decreased FXR occupancy in Atp7b-/- versus WT mice was observed genes of metabolic pathways and bile acid homeostasis, while enrichment of FXR binding was observed pathways associated with cellular damage, such as the focal adhesion pathway. Consistent with decreased FXR function, serum and liver bile acid concentrations were higher in Atp7b-/- mice than in WT mice. Comparison of bile acid profiles in the serum of WD patients with “liver,” “neurological,” or “mixed” disease vs. healthy controls also revealed increases in specific bile acids in WD-liver vs. healthy controls. Conclusions: Atp7b-/- mice and WD patients exhibited changes in serum bile acid speciation, likely due to FXR dysfunction. These findings provide new insights into possible aberrant bile acid homeostasis in patients with WD.
Project description:Background & Aims: Wilson disease (WD) is an autosomal recessive disorder that results in excessive hepatic copper causing hepatic steatosis, inflammation, fibrosis, cirrhosis, and liver failure. Previous studies have revealed dysregulation of many FXR metabolic target genes in animal models of WD, including Bsep, the major determinant of bile flow. Approach & Results: We tested the hypothesis that the FXR-cistrome is decreased in Atp7b-/- mice in accord with dysregulated bile acid homeostasis. RNA-Seq and ChIP-Seq analyses of Atp7b-/- and wild-type (WT) mouse livers confirmed that significantly altered transcripts and FXR-binding events overlapped. Decreased FXR occupancy in Atp7b-/- versus WT mice was observed genes of metabolic pathways and bile acid homeostasis, while enrichment of FXR binding was observed pathways associated with cellular damage, such as the focal adhesion pathway. Consistent with decreased FXR function, serum and liver bile acid concentrations were higher in Atp7b-/- mice than in WT mice. Comparison of bile acid profiles in the serum of WD patients with “liver,” “neurological,” or “mixed” disease vs. healthy controls also revealed increases in specific bile acids in WD-liver vs. healthy controls. Conclusions: Atp7b-/- mice and WD patients exhibited changes in serum bile acid speciation, likely due to FXR dysfunction. These findings provide new insights into possible aberrant bile acid homeostasis in patients with WD.
Project description:Nonalcoholic fatty liver disease represents a spectrum of pathology that ranges from benign steatosis to potentially-progressive steatohepatitis and affects more than 30% of US adults. Advanced NAFLD is associated with increased morbidity and mortality from cirrhosis, primary liver cancer, cardiovascular disease and extrahepatic cancers. Accurate identification of patients at risk for advanced NAFLD is challenging. The aims of this study were to define the liver gene expression patterns that distinguish mild from advanced NAFLD and to develop a gene expression profile associated with advanced NAFLD.
Project description:Nonalcoholic fatty liver disease represents a spectrum of pathology that ranges from benign steatosis to potentially-progressive steatohepatitis and affects more than 30% of US adults. Advanced NAFLD is associated with increased morbidity and mortality from cirrhosis, primary liver cancer, cardiovascular disease and extrahepatic cancers. Accurate identification of patients at risk for advanced NAFLD is challenging. The aims of this study were to define the liver gene expression patterns that distinguish mild from advanced NAFLD and to develop a gene expression profile associated with advanced NAFLD. We analyzed total RNA from 72 patients with NAFLD (40 with mild NAFLD, fibrosis stage 0-1 and 32 with advanced NAFLD, fibrosis stage 3-4) and developed a gene profile associated with advanced NAFLD. This dataset is part of the TransQST collection.
Project description:Wilson disease (WD) is a severe metabolic disorder caused by genetic inactivation of copper-transporting ATPase ATP7B. In WD, copper accumulates in several tissues, particularly in the liver, inducing marked time-dependent pathological changes. To identify initial events in the copper-dependent development of liver pathology we utilized the Atp7b-/- mice, an animal model for WD. Analysis of mRNA from livers of control and Atp7b-/- 6 weeks-old mice using oligonucleotide arrays revealed specific changes of the transcriptome at this stage of copper accumulation. Few messages (29 up-regulated and 46 down-regulated) change their abundance more than 2-fold pointing to the specific effect of copper on gene expression/mRNA stability. The gene ontology analysis revealed copper effects on distinct metabolic pathways. Keywords: comparative genomic hybridization