High risk human papillomavirus (HPV) infection and genome integration with pronounced expression of the viral E6/E7 oncogenes is the major cause of cervical cancer. Emerging evidence suggests that HPV reprograms host metabolism to support viral persistence and cellular transformation. However, global HPV oncogene-induced lipidomic reprogramming remains poorly understood, particularly at early stages of HPV-induced transformation. We sought to define the regulation of lipid metabolism in squamous epithelia of transgenic mice expressing the HPV16 oncogene E6 alone or in conjunction with E7. Untargeted lipidomics was used to identify novel lipid biomarkers in the skin and female reproductive tract (FRT) of HPV16 E6 and E6/E7 transgenic compared to wild-type (WT) mice. To investigate enzymatic dysregulation of lipids by HPV oncogene expression, we employed Lipid Network Explorer (LINEX2), which analyzes lipidomics data through lipid enrichment analysis. We also used the Global Natural Product Social Molecular Networking (GNPS) platform to enhance lipid identification, exploring molecular networking to improve feature annotation. Our lipidomic analysis produced several new observations. First, E6 expression caused a consistent alteration of glycerophospholipids, with particularly significant substrate-product shifts in the phosphatidylcholine (PC) to lysophosphatidylcholine (LPC) pathway in the skin. Second, E6/E7 expression caused a dysregulation of glucosylceramide (GlcCer) biosynthesis. Third, both E6/E7 expressing skin and FRT tissues exhibited a redox imbalance and increased levels of oxidized lipids, including oxylipins and several oxidized PCs. These findings suggest that HPV oncoproteins drive lipid reprogramming, potentially contributing to early HPV-related tumorigenesis. These findings provide new insights into HPV‑induced lipid reprogramming and establish a framework for future studies examining the functional and clinical relevance of lipid alterations in HPV‑associated cancers.

Cell fusion is a fundamental process for skeletal muscle development and regeneration. The muscle-specific fusogens Myomaker and Myomerger are necessary for fusion of muscle cells and together are sufficient for fusion. A mechanistic understanding of Myomaker activity is lacking. Here, we identify ether-linked phospholipids as modulators of Myomaker activity. Although Myomaker shows homology to ceramidases, we observe no ability for the protein to regulate ceramides. Treatment of myocytes with a ceramide synthase inhibitor increases fusion, and lipidomic analysis reveals an increase in cellular ether lipids. Using a lentiviral pseudotyping system to isolate Myomaker-containing membranes, we find an enrichment of ether lipids. Elevating ether lipids in Myomaker-expressing cells induces fusion, even without Myomerger, and correlates with cell surface exposure of phosphatidylethanolamine and phosphatidylserine, indicating a role for Myomaker in remodeling plasma membrane lipid distribution. These findings reveal a link between lipid asymmetry and the molecular machinery responsible for muscle cell fusion.

Pruritus is a debilitating symptom frequently affecting patients with cholestatic liver disease, often resistant to conventional antipruritic therapies. The pathogenesis of cholestatic pruritus (CP) is multifactorial, implicating not only bile acids but also a complex array of other potential pruritogenic mediators and neural signaling pathways. Identification of the exact pruritogen has been elusive, and gaps remain in understanding the pathogenesis of pruritus, so developing targeted treatments is critical. The stratum corneum (SC), the outermost lipid-rich layer of the skin, may act as a reservoir for circulating pruritogens, offering a novel window to explore the pathogenesis of CP. Recent advancements in lipidomics and non-invasive tape stripping have enabled detailed profiling of SC lipid alterations in disease states. In this review, we synthesize the current understanding of CP and its candidate pruritogens and describe state-of-the-art approaches for SC lipid analysis, combining tape stripping to sample the skin surface with mass spectrometry-based lipidomics. Finally, we summarize cutaneous molecular findings and discuss how these techniques are facilitating biomarker discovery and informing therapeutic development. This review discusses the paradigm shift from a single-molecule perspective to a more integrated view of CP as a product of complex mediator interactions and highlights the potential of SC profiling to uncover novel targets for intervention strategies.

BACKGROUND & AIMS:Bile acid reflux has been implicated as a cause for esophagitis, pulmonary fibrosis, and other aerodigestive disorders. The goal of this study was to determine the relationship between gastric and lung bile acid concentrations and if diet was a modifiable risk factor to reduce bile acid reflux. METHODS:We prospectively recruited children with oropharyngeal dysphagia and respiratory symptoms undergoing aerodigestive testing. Gastric and, when available, lung bile acid concentrations were quantified using liquid chromatography-mass spectrometry. In a subgroup of enterally fed patients, serum 7α-hydroxy-4-cholesten-3-one (C4) levels were measured. RESULTS:In this prospective cohort of 141 participants, gastric bile acids concentrations were highest in those fed orally compared with enteral tubes (P = .008). Gastric bile acid was a strong predictor of lung bile acids in children receiving blenderized tube feeds (r = 0.57; P = .03), but not formula (r = 0.34; P = .09), or oral feeds (r = -0.02; P = .89). Low lung bile acid concentration predicted low neutrophil counts in the lung (r = 0.39; P = .003), as did use of blenderized tube feeds (oral, 5 [interquartile range (IQR), 26]; formula, 7.5 [IQR, 37.5]; blenderized, 0 [IQR, 0]; P = .008). Quartile gastric and lung bile acids were strong predictors of hospitalization rates (P< .001 for both). Serum C4 levels, a surrogate for bile acid synthesis rate, did not support evidence of excessive bile acid loss with blenderized tube feeds (blenderized, 2.3 [IQR, 11.3] vs formula, 18.1 [IQR, 34.8] ng/mL; P = .03). CONCLUSIONS:For patients at high risk for bile acid-related aerodigestive complications, tube and diet type may affect gastric bile acid concentrations, in turn impacting important clinical outcomes of hospitalization rates and airway inflammation.

Background/Objectives: Bile acid synthesis disorders (BASDs) represent a distinct category of progressive familiar cholestatic liver disease. A novel targeted mass spectrometry assay was developed for the accurate measurement of the major urinary atypical bile acids and bile alcohols that are biomarkers for HSD3B7, AKR1D1, CYP7B1 and CYP27A1 deficiencies, the four most common BASDs. Methods: Stable-isotope dilution UPLC tandem mass spectrometry was used for the simultaneous quantification of 12 key atypical bile acid biomarkers in urine from patients with BASD. Typical concentration ranges for these metabolites were established from urine samples from patients with biochemically and/or genetically confirmed BASD and compared with non-cholestatic and cholestatic controls. Results: The separation of major 3β-hydroxy-Δ5-bile acid sulfates, taurine- and glycine-conjugated 3-oxo-Δ4-bile acids, and bile alcohol glucuronides was achieved in a 20 min chromatographic run with intra- and inter-batch imprecisions of <15% for all metabolites. The mean ± SEM urinary concentration of total 3β-sulfated-Δ5-cholenoic acids in patients with HSD3B7 deficiency was 704 ± 204 µmol/L (n = 22), approximately 2000-fold higher than in cholestastic patients (n = 168) or non-cholestatic controls (n = 127). Similarly, the concentration of 5β-cholestane-3α,7α,12α,24,25-pentol-glucuronide, the major bile alcohol, in patients with CYP27A1 deficiency was 95 ± 17 µmol/L (n = 12). For CYP7B1 deficiency, two confirmed cases showed elevated levels (average, 7.5 µmol/L) of the glycine conjugate of 3β-sulfooxy-Δ5-bile acid. In AKR1D1 deficiency, total 3-oxo-Δ4-bile acids in urine were elevated (81 ± 16 µmol/L, n = 48), but concentrations showed overlap with cholestatic and non-cholestatic controls. Conclusions: A novel quantitative tandem mass spectrometry assay is described for the measurement of the major atypical metabolites and biomarkers in urine applicable to the accurate monitoring of treatment responses, and for the first time typical concentration ranges are established for each of these BASDs.

Neuronopathic Gaucher disease (nGD) is a lysosomal storage disorder caused by GBA1 mutations, leading to defective acid β-glucosidase (GCase) and accumulation of glycosphingolipid substrates, causing inflammation and neurodegeneration. Patients with nGD manifest severe neurological symptoms, but current animal models fail to fully recapitulate the human condition, posing a major barrier to the development of effective therapies targeting the brain. To bridge this gap, we have developed midbrain-like organoids (MLOs) from human induced pluripotent stem cells of nGD patients with GBA1L444P/P415R and GBA1L444P/RecNcil mutations to model nGD brain pathogenesis. These nGD MLOs exhibited GCase deficiency, resulting in diminished enzymatic function, accumulation of lipid substrates, widespread transcriptomic changes, and impaired dopaminergic neuron differentiation, mirroring nGD pathology. GBA1 mutation correction mediated by CRISPR/Cas9 restored GCase activity, normalized lipid substrate levels, and rescued dopaminergic neuron function, confirming the causal role of GBA1 mutations during early brain development. Using this novel platform, we further evaluated therapeutic strategies, including SapC-DOPS nanovesicles delivering GCase, AAV9-GBA1 gene therapy, and substrate reduction therapy with GZ452, a glucosylceramide synthase inhibitor currently under clinical investigation. These treatments either restored GCase activity, reduced lipid substrate accumulation, improved autophagic and lysosomal abnormalities, or ameliorated dysregulated genes involved in neural development. These patient-specific, 3D neural models offer a transformative, physiologically relevant platform for unraveling disease mechanisms and accelerating the discovery of therapies for patients with nGD.

Clonal haematopoiesis of indeterminate potential (CHIP) involves the gradual expansion of mutant pre-leukaemic haematopoietic cells, which increases with age and confers a risk for multiple diseases, including leukaemia and immune-related conditions1. Although the absolute risk of leukaemic transformation in individuals with CHIP is very low, the strongest predictor of progression is the accumulation of mutant haematopoietic cells2. Despite the known associations between CHIP and increased all-cause mortality, our understanding of environmental and regulatory factors that underlie this process during ageing remains rudimentary. Here we show that intestinal alterations, which can occur with age, lead to systemic dissemination of a microbial metabolite that promotes pre-leukaemic cell expansion. Specifically, ADP-D-glycero-β-D-manno-heptose (ADP-heptose), a biosynthetic bi-product specific to Gram-negative bacteria3-5, is uniquely found in the circulation of older individuals and favours the expansion of pre-leukaemic cells. ADP-heptose is also associated with increased inflammation and cardiovascular risk in CHIP. Mechanistically, ADP-heptose binds to its receptor, ALPK1, triggering transcriptional reprogramming and NF-κB activation that endows pre-leukaemic cells with a competitive advantage due to excessive clonal proliferation. Collectively, we identify that the accumulation of ADP-heptose represents a direct link between ageing and expansion of rare pre-leukaemic cells, suggesting that the ADP-heptose-ALPK1 axis is a promising therapeutic target to prevent progression of CHIP to overt leukaemia and immune-related conditions.

Pediatric patients undergoing hematopoietic stem cell transplant (HSCT) are at high risk for fungal infections, including Candida, Aspergillus, and Mucorales, necessitating the use of broad-spectrum antifungal agents such as posaconazole for prophylaxis and at times for treatment of invasive fungal infections. When first approved, posaconazole was limited to an immediate-release oral suspension, which exhibited unreliable absorption dependent on co-administration with high-fat meals. During HSCT, patients commonly have significant nausea, vomiting, and decreased enteral intake, making this formulation particularly challenging. In 2014, intravenous (IV) posaconazole became available with its first approval only for adult patients, as there were no data on its use in pediatric patients. This approval has since been expanded to include pediatric patients as young as 2 yr of age. In terms of dosing, however, clinical practice experience supports a significantly higher starting dose than the manufacturer-recommended 6 mg/kg/dose. Current literature involving the use of IV posaconazole in pediatric HSCT patients is limited to studies with small sample sizes and varying dose ranges recommended to achieve posaconazole target levels. Describe the safety and efficacy of IV posaconazole for prophylaxis and treatment of invasive fungal infections in pediatric HSCT patients. This was a single-center, retrospective chart review of pediatric HSCT patients who received IV posaconazole from January 1, 2015, to August 1, 2023. One hundred eighty-two patients were identified as receiving at least one dose of IV posaconazole, and 109 were included in the final analysis. Of these, 105 (96.3%, 95% confidence interval [0.924, 1.01]) patients were able to achieve their target level within a single course of IV posaconazole, defined as continuous treatment with an interruption of no more than 5 days. The median weight-based dose after therapeutic dose adjustments (if necessary), achieving their target level was 10 mg/kg for both prophylaxis and treatment. Additionally, a median fixed dose of 300 mg for prophylaxis (patients weighing ≥30 kg) and 400 mg (patients weighing ≥40 kg) for treatment were able to achieve target levels. Seventy-eight patients received IV posaconazole for prophylaxis, with three patients (3.8%) requiring an escalation to treatment dosing of an antifungal. Thirty-one patients received IV posaconazole for treatment of either probable (n = 21, 19.3%) or proven fungal infection (n = 10, 9.2%). A total of 22 patients discontinued IV posaconazole due to an adverse event, with hepatic dysfunction being the most common reason (n = 19, 86%). Thirteen patients were able to restart posaconazole after resolution of liver function tests. There was not an association between high levels and discontinuation due to an adverse event. Administration of a loading dose of IV posaconazole at 10 mg/kg every 12 h for two doses, followed by a maintenance dose of 10 mg/kg every 24 h was an effective starting dose for achieving target levels for prophylaxis and treatment in pediatric HSCT recipients. The most common adverse event leading to discontinuation of IV posaconazole was hepatic dysfunction, but a substantial portion of these patients were able to restart posaconazole without repeated issue. To our knowledge, this was the largest study to date evaluating the efficacy of IV posaconazole in pediatric HSCT patients.

Background There is a paucity of information on tobacco and cannabis use patterns in pregnant women who use opioids. Our objective was to examine sociodemographic, tobacco, and cannabis use patterns during pregnancy among pregnant women with opioid use. Methods We recruited 206 pregnant women with biochemically verified opioid use during pregnancy, of whom 98 self-reported taking only medications for opioid use disorder (MOUD) and 108 reported taking other opioids during pregnancy. We examined sociodemographic characteristics and self-report of tobacco and cannabis use overall and by trimester. Chi-square and t-tests were used to assess differences between the MOUD-only vs other opioids groups. Logistic regression models were used to examine differences in factors associated with tobacco and cannabis use. Results Mean (SD) age was 30.7 years (4.6); 81.9 % were non-Hispanic White, and 92.6 % had public insurance. Of the 91 women taking MOUD only and completing the substance use self-report, 50 (54.9 %) reported tobacco use only, 3 (3.3 %) reported cannabis use only, and 24 (26.4 %) reported both tobacco and cannabis use. Tobacco and cannabis use was similar for women taking other opioids (p = 0.98). Adjusted odds ratios indicated that there was consistent use of all tobacco products (p = 0.28) including e-cigarette products (p = 0.18) throughout all 3 trimesters of pregnancy. There was decreased use of cannabis over the course of pregnancy with 29.8 % using cannabis during the first trimester and 16.5 % during the last trimester (p = 0.0003). Conclusions While we observed no differences in tobacco and cannabis use between those taking MOUD only versus other opioids, we observed high rates of tobacco and cannabis use among pregnant women with opioid use. These findings underscore the need for tobacco and cannabis use education and cessation interventions throughout pregnancy for those with OUD.

Isoflavones are naturally occurring compounds found in a wide range of plants, but among commonly consumed foods are especially abundant in soybeans and foods derived from this legume. Much of the substantial amount of research conducted on soy protein and soy foods over the past 30 y is because of their isoflavone content. Research interest in isoflavones increased dramatically beginning in the early 1990s as evidence highlighted their possible role in the prevention of a wide range of cancers, including breast, prostate, and colon cancer. Recognition that isoflavones preferentially bind to estrogen receptor (ER)β in comparison with ERα provided a conceptual basis for classifying these diphenolic molecules as selective ER modulators (SERMs). Isoflavone research soon greatly expanded beyond cancer to include areas such as coronary artery disease, bone health, cognitive function, and vasomotor symptoms of menopause. Nevertheless, safety concerns about isoflavones, based primarily on the results of rodent studies and presumed estrogenic effects, also arose. However, recent work challenges the traditional view of the estrogenicity of isoflavones. Furthermore, safety concerns have largely been refuted by intervention and population studies. On the other hand, investigation of the proposed benefits of isoflavones has produced inconsistent data. The small sample size and short duration common to many intervention trials, combined with marked interindividual differences in isoflavone metabolism, likely contribute to the conflicting findings. Also, many different intervention products have been employed, which vary not only in the total amount, but also in the relative proportion of the 3 soybean isoflavones, and the form in which they are delivered (glycoside compared with aglycone). For those interested in exploring the proposed benefits of isoflavones, studies justify an intake recommendation of ∼50 mg/d, an amount provided by ∼2 servings of traditional Asian soy foods.

Lipids are essential biomolecules involved in membrane structure, energy storage, and intracellular signaling. Dysregulation of lipid metabolism (dyslipidemia) plays a central role in a wide spectrum of pediatric metabolic disorders, including both inherited and acquired conditions. Recent and rapid advances in mass spectrometry-based lipidomics have enabled high-resolution profiling of more than one-thousand lipid species, facilitating the discovery of disease-specific lipid signatures that were previously undetectable with conventional biochemical assays. In parallel, the rising prevalence of pediatric obesity, diabetes, asthma, metabolic dysfunction-associated steatotic liver disease (MASLD; formerly referred to as non-alcoholic fatty liver disease or NAFLD) and cancers has accelerated research aimed at uncovering molecular pathways underlying these conditions. Lipidomic approaches have also improved the identification and characterization of rare metabolic disorders. As analytical technologies continue to advance, lipidomics is poised to become a cornerstone of precision medicine in pediatrics, offering new opportunities for early diagnosis, risk stratification, and therapeutic targeting.

The immunosuppressant mycophenolate mofetil (MMF) is used off-label in patients with systemic lupus erythematosus (SLE) although the optimum dosing regimen is not well established. This study evaluated the use of volumetric absorptive microsampling (VAMS) for capillary whole blood collected by finger-prick, combined with tandem mass spectrometry and limited timepoint sampling to determine concentrations of mycophenolic acid (MPA) and its glucuronide conjugate, MPA-7-O-glucuronide (MPAG) in SLE patients. This approach permitted pharmacokinetically guided optimized dosing of MPA. Blood was collected by finger-prick and venipuncture from patients (n = 10) at trough, 30, and 120 min postdosing with MMF. MPA/MPAG concentrations were assayed from dried VAMS devices by stable-isotope dilution LC-MS-MS and compared to MPA/MPAG concentrations measured in plasma by high performance liquid chromatography after adjusting for hematocrit. There was no significant difference between MPA concentrations from VAMS-collected dried capillary blood hematocrit-adjusted and those for plasma. The area under the concentration-time curve (AUC) estimated from plasma equivalent concentrations converted from capillary VAMS results correlated well with the AUC estimated from plasma concentrations (R2 = 0.97). The plasma pharmacokinetics of MMF metabolites can be reliably estimated from concentrations in capillary blood using VAMS devices and only 3 timed collections. Sampling whole blood by finger-prick, a less invasive approach for patients, coupled with the specificity of LC-MS/MS can be accurately used as an alternative to plasma sampling to establish the optimal dosing regimen of MMF for patients with SLE based on dried blood samples.

Background/Objectives: The Fanconi anemia (FA) pathway is essential for the repair of DNA interstrand crosslinks and maintenance of genomic stability. Germline loss of FA pathway function in the inherited Fanconi anemia syndrome leads to increased DNA damage and a range of clinical phenotypes, including a heightened risk of head and neck squamous cell carcinoma (HNSCC). Non-synonymous FA gene mutations are also observed in up to 20% of sporadic HNSCCs. The mechanistic target of rapamycin (mTOR) is known to stimulate cell growth, anabolic metabolism including protein synthesis, and survival following genotoxic stress. Methods/Results: Here, we demonstrate that FA− deficient (FA−) HNSCC cells exhibit elevated intracellular amino acid levels, increased total protein content, and an increase in protein synthesis indicative of enhanced translation. These changes are accompanied by hyperactivation of the mTOR effectors translation initiation factor 4E Binding Protein 1 (4E-BP1) and ribosomal protein S6. Treatment with the mTOR inhibitor rapamycin reduced the phosphorylation of these targets and blocked translation specifically in FA− cells but not in their isogenic FA− proficient (FA+) counterparts. Rapamycin-mediated mTOR inhibition sensitized FA− but not FA+ cells to rapamycin under nutrient stress, supporting a therapeutic metabolism-based vulnerability in FA− cancer cells. Conclusions: These findings uncover a novel role for the FA pathway in suppressing mTOR signaling and identify mTOR inhibition as a potential strategy for targeting FA− HNSCCs.

Fanconi anemia (FA) is a rare inherited disorder characterized by progressive bone marrow failure (BMF) and a predisposition to malignancy. Systemic reactive-oxygen species (ROS) and increased sensitivity of FA hematopoietic progenitors to ROS play a key role in the pathogenesis of BMF. Treatment with antioxidants improve hematopoietic function in Fancc-/- mice. We report the safety, tolerability, and pharmacokinetics (PK) of quercetin, a naturally occurring antioxidant in the first dose-finding Phase 1 study in patients with FA. Twelve patients (median age 7 years, range: 3-21) received oral quercetin twice daily for 4 months. Quercetin was well tolerated at all dose levels. Allometrically bodyweight-adjusted dose with a maximum adult daily dose of 4000mg/day was established as the recommended dose of quercetin. Patients in an expansion cohort (n=18) were treated using this recommended dose for 6 months. A subset of patients showed reduced ROS levels in the peripheral blood and bone marrow stem cell compartment. Patients in the analysis cohort treated with the recommended dose of quercetin achieved an a priori defined optimal response of 25% reduction in the peripheral blood (PB) ROS level compared to baseline. Platelet counts remained stable to slightly improved over the study period (p=0.06). Absolute neutrophil counts (p=0.01) and hemoglobin levels gradually declined (p=0.001). In those with evidence of BMF at baseline, 8 out of 15 patients (53%) had a hematological response at some point following quercetin treatment. Fluctuations in counts are common in patients with FA limiting accurate assessment of the impact of quercetin use in FA. NCT# 01720147

Acute pancreatitis (AP) and chronic pancreatitis (CP) are distinct inflammatory conditions with significant clinical burden, including associated complications and mortality. These pancreatic conditions share overlapping pathophysiologic features. Although AP can be followed by recurrent episodes (recurrent acute pancreatitis, RAP), most CP does not follow a simple linear progression from AP; rather, CP reflects sustained processes causing injury to the pancreas (e.g., toxic-metabolic, genetic, obstructive), leading to fibrosis and organ dysfunction. Lipidomics and metabolomics can provide insights into the pathophysiology of the disease. Although researchers have extensively explored lipids and metabolites to better understand disease mechanisms, comprehensive detailed insights into the pathways and intricate roles these molecules play in pancreatitis remain unidentified. This gap can be partially attributed to limited availability of human samples from disease subgroups in pancreatitis, and current technological constraints in analytical methods, particularly regarding complete lipid and metabolite detection, identification, and quantification. In this review, we summarize lipidomic and metabolomic workflows in the context of understanding pancreatitis pathophysiology, including their design and analytical strategies. We also highlight clinical studies on pancreatitis, utilizing lipidomics and metabolomics as a tool to identify altered or dysregulated lipids or metabolites, and their association with the disease state and its progression.

BACKGROUND: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 farnesoid X receptor (FXR) metabolic target genes in WD, including the bile salt exporter pump, the major determinant of bile flow. METHODS:We tested the hypothesis that the FXR-cistrome is decreased in Atp7b-/- mice in accord with dysregulated bile acid homeostasis. RESULTS:FXR binding within Atp7b-/- mouse livers displayed surprising complexity: FXR binding was increased in distal intergenic regions but decreased in promoter regions in Atp7b-/- versus wild-type mice. Decreased FXR occupancy in Atp7b-/- versus wild-type mice was observed in hepatocyte metabolic and bile acid homeostasis pathways, while enrichment of FXR binding was observed in pathways associated with cellular damage outside of hepatocytes. Indeed, disparate FXR occupancy was identified in parenchymal and non-parenchymal marker genes in a manner that suggests decreased FXR activity in parenchymal cells, as expected, and increased FXR activity in non-parenchymal cells. Consistent with altered FXR function, serum and liver bile acid concentrations were higher in Atp7b-/- mice than in wild-type mice. Comparison of bile acid profiles in the serum of WD patients with "liver," "neurological," or "mixed" disease versus healthy controls also revealed increases in specific bile acids in WD-liver versus healthy controls. CONCLUSIONS:We identified novel FXR-occupancy across the genome that varied in parenchymal and non-parenchymal cells, demonstrating complex FXR regulation of metabolic and hepatocellular stress pathways in Atp7b-/- mice. Dynamic changes in FXR activity support our novel finding of altered bile acid metabolism in Atp7b-/- mice and WD patients.