GSK805 inhibits alpha-smooth muscle expression and modulates liver inflammation without impairing the well-being of mice.

Cholestatic liver diseases, such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), lead to inflammation and severe hepatic damage with limited therapeutic options. This study assessed the efficacy of the inverse RORγt agonist, GSK805, both in vitro using the hepatic stellate cell-line LX-2 and in vivo using male bile duct-ligated BALB/c mice. In vitro, 0.3 µM GSK805 reduced alpha-smooth muscle actin expression in LX-2 cells. In vivo, GSK805 significantly decreased IL-23R, TNF-α, and IFN-γ expression in cholestatic liver. Despite high concentrations of GSK805 in the liver, no significant reduction in fibrosis was noticed. GSK805 significantly increased aspartate aminotransferase and alanine aminotransferase activity in the blood, while levels of glutamate dehydrogenase, alkaline phosphatase, and bilirubin were not substantially increased. Importantly, GSK805 did neither increase an animal distress score nor substantially reduce body weight, burrowing activity, or nesting behavior. These results suggest that a high liver concentration of GSK805 is achieved by daily oral administration and that this drug modulates inflammation in cholestatic mice without impairing animal well-being.

Apical bulkheads accumulate as adaptive response to impaired bile flow in liver disease.

Hepatocytes form bile canaliculi that dynamically respond to the signalling activity of bile acids and bile flow. Little is known about their responses to intraluminal pressure. During embryonic development, hepatocytes assemble apical bulkheads that increase the canalicular resistance to intraluminal pressure. Here, we investigate whether they also protect bile canaliculi against elevated pressure upon impaired bile flow in adult liver. Apical bulkheads accumulate upon bile flow obstruction in mouse models and patients with primary sclerosing cholangitis (PSC). Their loss under these conditions leads to abnormally dilated canaliculi, resembling liver cell rosettes described in other hepatic diseases. 3D reconstruction reveals that these structures are sections of cysts and tubes formed by hepatocytes. Mathematical modelling establishes that they positively correlate with canalicular pressure and occur in early PSC stages. Using primary hepatocytes and 3D organoids, we demonstrate that excessive canalicular pressure causes the loss of apical bulkheads and formation of rosettes. Our results suggest that apical bulkheads are a protective mechanism of hepatocytes against impaired bile flow, highlighting the role of canalicular pressure in liver diseases.

Protective function of sclerosing cholangitis on IBD.

OBJECTIVE: There is a strong clinical association between IBD and primary sclerosing cholangitis (PSC), a chronic disease of the liver characterised by biliary inflammation that leads to strictures and fibrosis. Approximately 60%-80% of people with PSC will also develop IBD (PSC-IBD). One hypothesis explaining this association would be that PSC drives IBD. Therefore, our aim was to test this hypothesis and to decipher the underlying mechanism. DESIGN: Colitis severity was analysed in experimental mouse models of colitis and sclerosing cholangitis, and people with IBD and PSC-IBD. Foxp3+ Treg-cell infiltration was assessed by qPCR and flow cytometry. Microbiota profiling was carried out from faecal samples of people with IBD, PSC-IBD and mouse models recapitulating these diseases. Faecal microbiota samples collected from people with IBD and PSC-IBD were transplanted into germ-free mice followed by colitis induction. RESULTS: We show that sclerosing cholangitis attenuated IBD in mouse models. Mechanistically, sclerosing cholangitis causes an altered intestinal microbiota composition, which promotes Foxp3+ Treg-cell expansion, and thereby protects against IBD. Accordingly, sclerosing cholangitis promotes IBD in the absence of Foxp3+ Treg cells. Furthermore, people with PSC-IBD have an increased Foxp3+ expression in the colon and an overall milder IBD severity. Finally, by transplanting faecal microbiota into gnotobiotic mice, we showed that the intestinal microbiota of people with PSC protects against colitis. CONCLUSION: This study shows that PSC attenuates IBD and provides a comprehensive insight into the mechanisms involved in this effect.

HLA-DPA1*02:01~B1*01:01 is a risk haplotype for primary sclerosing cholangitis mediating activation of NKp44+ NK cells.

OBJECTIVE: Primary sclerosing cholangitis (PSC) is characterised by bile duct strictures and progressive liver disease, eventually requiring liver transplantation. Although the pathogenesis of PSC remains incompletely understood, strong associations with HLA-class II haplotypes have been described. As specific HLA-DP molecules can bind the activating NK-cell receptor NKp44, we investigated the role of HLA-DP/NKp44-interactions in PSC. DESIGN: Liver tissue, intrahepatic and peripheral blood lymphocytes of individuals with PSC and control individuals were characterised using flow cytometry, immunohistochemical and immunofluorescence analyses. HLA-DPA1 and HLA-DPB1 imputation and association analyses were performed in 3408 individuals with PSC and 34 213 controls. NK cell activation on NKp44/HLA-DP interactions was assessed in vitro using plate-bound HLA-DP molecules and HLA-DPB wildtype versus knock-out human cholangiocyte organoids. RESULTS: NKp44+NK cells were enriched in livers, and intrahepatic bile ducts of individuals with PSC showed higher expression of HLA-DP. HLA-DP haplotype analysis revealed a highly elevated PSC risk for HLA-DPA1*02:01~B1*01:01 (OR 1.99, p=6.7×10-50). Primary NKp44+NK cells exhibited significantly higher degranulation in response to plate-bound HLA-DPA1*02:01-DPB1*01:01 compared with control HLA-DP molecules, which were inhibited by anti-NKp44-blocking. Human cholangiocyte organoids expressing HLA-DPA1*02:01-DPB1*01:01 after IFN-γ-exposure demonstrated significantly increased binding to NKp44-Fc constructs compared with unstimulated controls. Importantly, HLA-DPA1*02:01-DPB1*01:01-expressing organoids increased degranulation of NKp44+NK cells compared with HLA-DPB1-KO organoids. CONCLUSION: Our studies identify a novel PSC risk haplotype HLA-DP A1*02:01~DPB1*01:01 and provide clinical and functional data implicating NKp44+NK cells that recognise HLA-DPA1*02:01-DPB1*01:01 expressed on cholangiocytes in PSC pathogenesis.

Transposon-based oncogene integration in Abcb4(Mdr2)-/- mice recapitulates high susceptibility to cholangiocarcinoma in primary sclerosing cholangitis.

BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a dreaded complication of primary sclerosing cholangitis (PSC) that is difficult to diagnose and associated with high mortality. Lack of animal models of CCA recapitulating the hepatic microenvironment of sclerosing cholangitis has hindered the development of novel treatments. Herein, we sought to develop a mouse model of PSC-associated CCA. METHODS: Ten-week-old Mdr2-/- mice with congenital PSC-like disease, and healthy wild-type littermates were subjected to either modified retrograde biliary instillation or hydrodynamic tail vein injection of a sleeping beauty transposon-transposase plasmid system with activated AKT (myr-AKT) and Yap (YapS127A) proto-oncogenes (SB AKT/YAP1). The role of TGFß was interrogated via ALK5 inhibitor (SB-525334) administration. Tumor phenotype, burden and desmoplastic reaction were analyzed histologically and via RNA sequencing. RESULTS: While SB AKT/YAP1 plasmids administered via retrograde biliary injection caused tumors in Mdr2-/-, only 26.67% (4/15) of these tumors were CCA. Alternatively, hydrodynamic tail vein injection of SB AKT/YAP1 resulted in robust tumorigenesis in all fibrotic Mdr2-/- mice with high CCA burden compared to healthy mice. Tumors phenotypically resembled human CCA, expressed multiple CCA (but not hepatocellular carcinoma) markers, and exhibited a profound desmoplastic reaction. RNA sequencing analysis revealed profound transcriptional changes in CCA evolving in a PSC-like context, with specific alterations in multiple immune pathways. Pharmacological TGFß inhibition led to enhanced immune cell tumor infiltration, reduced tumor burden and suppressed desmoplastic collagen accumulation compared to placebo. CONCLUSION: We established a new high-fidelity cholangiocarcinoma model in mice, termed SB CCA.Mdr2-/-, which recapitulates the increased susceptibility to CCA in the setting of biliary injury and fibrosis observed in PSC. Through transcriptomics and pharmacological studies, we show dysregulation of multiple immune pathways and TGFß signaling as potential drivers of CCA in a PSC-like microenvironment. IMPACT AND IMPLICATIONS: Animal models for primary sclerosing cholangitis (PSC)-related cholangiocarcinoma (PSC-CCA) are lacking. Thus, we have developed and characterized a new mouse model of PSC-CCA, termed SB CCA.Mdr2-/-, which features reliable tumor induction on a PSC-like background of biliary injury and fibrosis. Global gene expression alterations were identified and standardized tools, including automated whole slide image analysis methodology for tumor burden and feature analysis, were established to enable systematic research into PSC-CCA biology and formal preclinical drug testing.

Single-cell, single-nucleus, and spatial transcriptomics characterization of the immunological landscape in the healthy and PSC human liver.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is an immune-mediated cholestatic liver disease for which there is an unmet need to understand the cellular composition of the affected liver and how it underlies disease pathogenesis. We aimed to generate a comprehensive atlas of the PSC liver using multi-omic modalities and protein-based functional validation. METHODS: We employed single-cell and single-nucleus RNA sequencing (47,156 cells and 23,000 nuclei) and spatial transcriptomics (one sample by 10x Visium and five samples with Nanostring GeoMx DSP) to profile the cellular ecosystem in 10 PSC livers. Transcriptomic profiles were compared to 24 neurologically deceased donor livers (107,542 cells) and spatial transcriptomics controls, as well as 18,240 cells and 20,202 nuclei from three PBC livers. Flow cytometry was performed to validate PSC-specific differences in immune cell phenotype and function. RESULTS: PSC explants with parenchymal cirrhosis and prominent periductal fibrosis contained a population of cholangiocyte-like hepatocytes that were surrounded by diverse immune cell populations. PSC-associated biliary, mesenchymal, and endothelial populations expressed chemokine and cytokine transcripts involved in immune cell recruitment. Additionally, expanded CD4+ T cells and recruited myeloid populations in the PSC liver expressed the corresponding receptors to these chemokines and cytokines, suggesting potential recruitment. Tissue-resident macrophages, by contrast, were reduced in number and exhibited a dysfunctional and downregulated inflammatory response to lipopolysaccharide and interferon-γ stimulation. CONCLUSIONS: We present a comprehensive atlas of the PSC liver and demonstrate an exhaustion-like phenotype of myeloid cells and markers of chronic cytokine expression in late-stage PSC lesions. This atlas expands our understanding of the cellular complexity of PSC and has potential to guide the development of novel treatments. IMPACT AND IMPLICATIONS: Primary sclerosing cholangitis (PSC) is a rare liver disease characterized by chronic inflammation and irreparable damage to the bile ducts, which eventually results in liver failure. Due to a limited understanding of the underlying pathogenesis of disease, treatment options are limited. To address this, we sequenced healthy and diseased livers to compare the activity, interactions, and localization of immune and non-immune cells. This revealed that hepatocytes lining PSC scar regions co-express cholangiocyte markers, whereas immune cells infiltrate the scar lesions. Of these cells, macrophages, which typically contribute to tissue repair, were enriched in immunoregulatory genes and demonstrated a lack of responsiveness to stimulation. These cells may be involved in maintaining hepatic inflammation and could be a target for novel therapies.

Patients with autoimmune liver disease have glucose disturbances that mechanistically differ from steatotic liver disease.

Autoimmune liver diseases are associated with an increased risk of diabetes, yet the underlying mechanisms remain unknown. In this cross-sectional study, we investigated the glucose-regulatory disturbances in patients with autoimmune hepatitis (AIH, n = 19), primary biliary cholangitis (PBC, n = 15), and primary sclerosing cholangitis (PSC, n = 6). Healthy individuals (n = 24) and patients with metabolic dysfunction-associated steatotic liver disease (MASLD, n = 18) were included as controls. Blood samples were collected during a 120-min oral glucose tolerance test. We measured the concentrations of glucose, C-peptide, insulin, glucagon, and the two incretin hormones, glucose insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). We calculated the homeostasis model assessment of insulin resistance (HOMA-IR), whole body insulin resistance (Matsuda index), insulin clearance, and insulinogenic index. All patient groups had increased fasting plasma glucose and impaired glucose responses compared with healthy controls. Beta-cell secretion was increased in AIH, PBC, and MASLD but not in PSC. Patients with AIH and MASLD had hyperglucagonemia and hepatic, as well as peripheral, insulin resistance and decreased insulin clearance, resulting in hyperinsulinemia. Patients with autoimmune liver disease had an increased GIP response, and those with AIH or PBC had an increased GLP-1 response. Our data demonstrate that the mechanism underlying glucose disturbances in patients with autoimmune liver disease differs from that underlying MASLD, including compensatory incretin responses in patients with autoimmune liver disease. Our results suggest that glucose disturbances are present at an early stage of the disease.NEW & NOTEWORTHY Patients with autoimmune liver disease but without overt diabetes display glucose disturbances early on in their disease course. We identified pathophysiological traits specific to these patients including altered incretin responses.

The Epigenetic Reader, Bromodomain Containing 2, Mediates Cholangiocyte Senescence via Interaction With ETS Proto-Oncogene 1.

BACKGROUND & AIMS: We reported that cholangiocyte senescence, regulated by the transcription factor ETS proto-oncogene 1 (ETS1), is a pathogenic feature of primary sclerosing cholangitis (PSC). Furthermore, histone 3 lysine 27 is acetylated at senescence-associated loci. The epigenetic readers, bromodomain and extra-terminal domain (BET) proteins, bind acetylated histones, recruit transcription factors, and drive gene expression. Thus, we tested the hypothesis that BET proteins interact with ETS1 to drive gene expression and cholangiocyte senescence. METHODS: We performed immunofluorescence for BET proteins (BRD2 and 4) in liver tissue from liver tissue from PSC patients and a mouse PSC model. Using normal human cholangiocytes (NHCs), NHCs experimentally induced to senescence (NHCsen), and PSC patient-derived cholangiocytes (PSCDCs), we assessed senescence, fibroinflammatory secretome, and apoptosis after BET inhibition or RNA interference depletion. We assessed BET interaction with ETS1 in NHCsen and tissues from PSC patient, and the effects of BET inhibitors on liver fibrosis, senescence, and inflammatory gene expression in mouse models. RESULTS: Tissue from patients with PSC and a mouse PSC model exhibited increased cholangiocyte BRD2 and 4 protein (∼5×) compared with controls without disease. NHCsen exhibited increased BRD2 and 4 (∼2×), whereas PSCDCs exhibited increased BRD2 protein (∼2×) relative to NHC. BET inhibition in NHCsen and PSCDCs reduced senescence markers and inhibited the fibroinflammatory secretome. ETS1 interacted with BRD2 in NHCsen, and BRD2 depletion diminished NHCsen p21 expression. BET inhibitors reduced senescence, fibroinflammatory gene expression, and fibrosis in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine-fed and Mdr2-/- mouse models. CONCLUSION: Our data suggest that BRD2 is an essential mediator of the senescent cholangiocyte phenotype and is a potential therapeutic target for patients with PSC.

Genetic evidence of the causal relationship between chronic liver diseases and musculoskeletal disorders.

BACKGROUND: Chronic liver diseases constitute a major global public health burden, posing a substantial threat to patients' daily lives and even survival due to the potential development of musculoskeletal disorders. Although the relationship between chronic liver diseases and musculoskeletal disorders has received extensive attention, their causal relationship has not been comprehensively and systematically investigated. METHODS: This study aimed to assess the causal relationships between viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC), liver cirrhosis, and hepatocellular carcinoma (HCC) with osteoporosis, osteoarthritis, and sarcopenia through bidirectional Mendelian randomization (MR) research. The traits related to osteoporosis and osteoarthritis included both overall and site-specific phenotypes, and the traits linked to sarcopenia involved indicators of muscle mass and function. Random-effect inverse-variance weighted (IVW), weighted median, MR-Egger, and Causal Analysis Using the Summary Effect Estimates were used to evaluate causal effects, with IVW being the main analysis method. To enhance robustness, sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-PRESSO global test, funnel plots, leave-one-out analyses, and latent causal variable model. RESULTS: The forward MR analysis indicated that PSC can reduce forearm bone mineral density (beta = - 0.0454, 95% CI - 0.0798 to - 0.0110; P = 0.0098) and increase the risk of overall osteoarthritis (OR = 1.012, 95% CI 1.002-1.022; P = 0.0247), while HCC can decrease grip strength (beta = - 0.0053, 95% CI - 0.008 to - 0.0025; P = 0.0002). The reverse MR analysis did not find significant causal effects of musculoskeletal disorders on chronic liver diseases. Additionally, no heterogeneity or pleiotropy was detected. CONCLUSIONS: These findings corroborate the causal effects of PSC on osteoporosis and osteoarthritis, as well as the causal impact of HCC on sarcopenia. Thus, the implementation of comprehensive preventive measures is imperative for PSC and HCC patients to mitigate the risk of musculoskeletal disorders, ultimately improving their quality of life.

Genetic association and causal relationship between multiple modifiable risk factors and autoimmune liver disease: a two-sample mendelian randomization study.

BACKGROUND: The intricate etiology of autoimmune liver disease (AILD) involves genetic, environmental, and other factors that yet to be completely elucidated. This study comprehensively assessed the causal association between genetically predicted modifiable risk factors and AILD by employing Mendelian randomization. METHODS: Genetic variants associated with 29 exposure factors were obtained from genome-wide association studies (GWAS). Genetic association data with autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) were also obtained from publicly available GWAS. Univariate and multivariate Mendelian randomization analyses were performed to identify potential risk factors for AILD. RESULTS: Genetically predicted rheumatoid arthritis (RA) (OR = 1.620, 95%CI 1.423-1.843, P = 2.506 × 10- 13) was significantly associated with an increased risk of AIH. Genetically predicted smoking initiation (OR = 1.637, 95%CI 1.055-2.540, P = 0.028), lower coffee intake (OR = 0.359, 95%CI 0.131-0.985, P = 0.047), cholelithiasis (OR = 1.134, 95%CI 1.023-1.257, P = 0.017) and higher C-reactive protein (CRP) (OR = 1.397, 95%CI 1.094-1.784, P = 0.007) were suggestively associated with an increased risk of AIH. Genetically predicted inflammatory bowel disease (IBD) (OR = 1.212, 95%CI 1.127-1.303, P = 2.015 × 10- 7) and RA (OR = 1.417, 95%CI 1.193-1.683, P = 7.193 × 10- 5) were significantly associated with increased risk of PBC. Genetically predicted smoking initiation (OR = 1.167, 95%CI 1.005-1.355, P = 0.043), systemic lupus erythematosus (SLE) (OR = 1.086, 95%CI 1.017-1.160, P = 0.014) and higher CRP (OR = 1.199, 95%CI 1.019-1.410, P = 0.028) were suggestively associated with an increased risk of PBC. Higher vitamin D3 (OR = 0.741, 95%CI 0.560-0.980, P = 0.036) and calcium (OR = 0.834, 95%CI 0.699-0.995, P = 0.044) levels were suggestive protective factors for PBC. Genetically predicted smoking initiation (OR = 0.630, 95%CI 0.462-0.860, P = 0.004) was suggestively associated with a decreased risk of PSC. Genetically predicted IBD (OR = 1.252, 95%CI 1.164-1.346, P = 1.394 × 10- 9), RA (OR = 1.543, 95%CI 1.279-1.861, P = 5.728 × 10- 6) and lower glycosylated hemoglobin (HbA1c) (OR = 0.268, 95%CI 0.141-0.510, P = 6.172 × 10- 5) were positively associated with an increased risk of PSC. CONCLUSIONS: Evidence on the causal relationship between 29 genetically predicted modifiable risk factors and the risk of AIH, PBC, and PSC is provided by this study. These findings provide fresh perspectives on the management and prevention strategies for AILD.

Prevalence and clinical profiles of primary sclerosing cholangitis in China: Data from electronic medical records and systematic literature retrieval.

BACKGROUND & AIMS: Epidemiology of primary sclerosing cholangitis (PSC) is lacking in China. We aimed to estimate the period prevalence and depict the clinical features of PSC in China. METHODS: We identified and included PSC cases between 2000 and 2023 from two sources: electronic medical records (EMR) and systematical literature retrieval (SLR). The period prevalence of PSC was estimated by the multiplier method. Rate ratios (RRs) for PSC prevalence in relation to macroeconomic indicators were calculated by the negative binomial regression model. RESULTS: A total of 1358 PSC cases were retrieved from 299 hospitals (162 from EMR and 1196 from SLR). Males accounted for 55.7 % of the PSC cases and 25.7 % had concomitant inflammatory bowel disease (IBD). The estimated period prevalence of PSC from 2000 to 2023 was 2.36 (95 % CI: 1.82, 3.34) per 100,000. Males had a numerically higher PSC prevalence than females (2.56, 95 % CI: 1.97, 3.63 vs. 2.14, 95 % CI: 1.65, 3.04 per 100,000). The highest prevalence of PSC was in East China at 4.87 (95 % CI: 3.44, 7.18) per 100,000, followed by North China at 2.94 (95 % CI: 2.33, 3.74) per 100,000, and the lowest in South China at 0.92 (95 % CI: 0.66, 1.30) per 100,000. Regional per capita GDP (RR 1.65, 95 % CI: 1.03, 2.65) and healthcare expenditure (RR 1.94, 95 % CI: 1.13, 3.38) were identified to be associated with PSC prevalence. CONCLUSION: Our study showed the estimated PSC prevalence varied within China, but was generally lower than that in Western countries.

The risk of cancer in pediatric-onset immune-mediated inflammatory diseases - A nationwide study.

BACKGROUND AND OBJECTIVES: Adult-onset immune-mediated inflammatory disease (IMID) increases the risk of several cancers. However, data on pediatric-onset IMID (pIMID) remains scarce. We estimated the long-term cancer risk in pIMID and the association between medical treatment and specific cancers. METHODS: We used the nationwide Danish health registers to identify pIMID patients diagnosed from Jan 1, 1980 to Dec 31, 2018. Patients were matched with ten reference individuals based on age, sex, and residence. The primary exposure was pIMID, including autoimmune hepatitis, primary sclerosing cholangitis, Crohn's disease, ulcerative colitis, juvenile idiopathic arthritis, systemic lupus erythematosus, vasculitis, and connective tissue disease. Secondary exposures were immunomodulators and tumor necrosis factor-α antagonists (anti-TNFα). The primary outcome was cancer. Estimates are presented as hazard ratios adjusted for family income at diagnosis (AHR). RESULTS: We included 12,664 pIMID patients and 109,274 reference individuals. Median follow-up time was 10.6 (interquartile range: 5.4-17.7) years for patients and 10.2 (interquartile range: 5.2-17.3) years for reference individuals. Patients with pIMID had a twofold higher cancer risk (AHR 2.2 [95 % confidence interval (CI): 1.8-2.6]) compared with reference individuals. Thiopurine treatment was associated with a higher risk of lymphoma (AHR 6.1 [95%CI: 2.2-16.8]) and skin cancer (AHR 6.1 [95%CI: 2.4-15.4]). Anti-TNFα treatment was associated with a higher risk of lymphoma (AHR 4.9 [95%CI: 1.1-22.6]). CONCLUSIONS: We found an increased cancer risk in patients with pIMID followed into adulthood. Additionally, thiopurines and anti-TNFα were associated with increased lymphoma and skin cancer risks. This highlights the importance of individualized immunotherapy and cancer surveillance.

ANXA1 is identified as a key gene associated with high risk and T cell infiltration in primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease, with unclear pathogenesis. Although immune disorders, especially T cell infiltration, are thought to play a vital role in PSC, the specific pathogenesis mechanisms remain incompletely understood. This study evaluated the potential key gene associated with the PSC pathogenesis and analyzed the associations of the key gene with prognosis and immune cell infiltration by combining bioinformatics analysis and experimental verification. METHODS: Transcriptome data of PSC and normal human liver tissues (GSE159676) were obtained from the gene expression omnibus database. Differentially expressed genes (DEGs) were identified, and differences in biological states were analyzed. A protein-protein interaction (PPI) network was constructed. Hub genes were identified, and their expression was verified using transcriptome data of mice fed 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) and Mdr2-/- mice (GSE179993, GSE80776), as well as by immunohistochemistry staining on clinical samples. The correlations between the key gene and other factors were evaluated by Pearson's correlation coefficient. Immune cell infiltration into human liver (GSE159676) was analyzed by xCell and verified by immunofluorescence staining on PSC liver samples. RESULTS: Of the 185 DEGs identified, 113 were upregulated and 72 were downregulated genes in PSC. Genes associated with immune cell infiltration and fibrosis were significantly enriched in PSC. PPI network showed close interactions among DEGs. A module strongly associated with immune infiltration was identified, with annexin A1 (ANXA1) being the core gene. High expression of ANXA1 in PSC was confirmed in two public datasets and by immunohistochemistry staining on clinical samples. High ANXA1 expression was strongly associated with high-risk score for PSC. Also, ANXA1 expression was positively associated with chemokines and chemokine receptors and with the infiltration of immune cells, especially T cells, into liver with PSC. Immune infiltration, fibrosis, and cancer-related processes were markedly enriched in PSC with high expression of ANXA1. CONCLUSION: ANXA1 is a key gene associated with high risk and infiltration of immune cells, especially T cells, in PSC. These findings provide new insight into the key biomarker of PSC and suggest that targeting ANXA1 may be a valuable strategy for the treatment of PSC.

Multimodal Convolutional Neural Network-Based Algorithm for Real-Time Detection and Differentiation of Malignant and Inflammatory Biliary Strictures in Cholangioscopy: a Proof of Concept Study with Video.

BACKGROUND AND AIMS: Deep learning algorithms gained attention for detection (CADe) of biliary tract cancer (BTC) in digital single-operator cholangioscopy (dSOC). We developed a multimodal convolutional neural network (CNN) for detection (CADe) characterization and discriminating (CADx) between malignant, inflammatory and normal biliary tissue in raw dSOC videos. In addition, clinical metadata was included in the CNN algorithm to overcome limitations of image-only models. METHODS: Based on dSOC videos and images of 111 patients (total of 15,158 still frames), we developed and validated a real-time CNN-based algorithm for CADe and CADx. We established an image-only model and metadata injection approach. In addition, we validated frame-wise and case-based predictions on complete dSOC video sequences. Model embeddings were visualized and class-activation maps highlighted relevant image regions. RESULTS: The concatenation-based CADx approach achieved a per-frame AUC of 0.871, sensitivity of 0.809 (95% CI: [0.784-0.832]), specificity of 0.773 [0.761-0.785], PPV of 0.450 [0.423-0.467], and NPV of 0.946 [0.940-0.954] with respect to malignancy on 5,715 test frames from complete videos of 20 patients. For case-based diagnosis using average prediction scores, six out of eight malignant cases and all twelve benign cases were identified correctly. CONCLUSION: Our algorithm distinguishes malignant and inflammatory bile duct lesions in dSOC videos, indicating the potential of CNN-based diagnostic support systems for both, CADe and CADx. The integration of non-image data can improve CNN based support systems, targeting current challenges in the assessment of biliary strictures.

Association between autoimmune liver diseases and chronic hepatitis B: A multivariable Mendelian randomization study in European population.

BACKGROUND: Observational studies have indicated a link between autoimmune liver diseases (AILD) and chronic hepatitis B (CHB) through observational studies. The association between AILD and CHB remains indeterminate. METHODS: A two-sample Mendelian randomization (MR) analysis was conducted to scrutinize the causal nexus between AILD and CHB utilizing summary statistics derived from extensive genome-wide association studies (GWASs) in European populations. The primary statistical methodology employed was the inverse variance-weighted (IVW) method to deduce the causal connection of AILD on CHB. This study incorporated primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), and autoimmune hepatitis (AIH) as subtypes of AILD. Additionally, we conducted a multivariable MR (MVMR) analysis to account for the potential confounding effects of smoking, alcohol consumption, body mass index (BMI), and some autoimmune diseases. RESULTS: Our MR investigation encompassed a cohort of 725,816 individuals. The MR analysis revealed that genetically predicted PSC significantly correlated with a reduced risk of CHB (IVW OR = 0.857; 95%CI: 0.770-0.953, P = 0.005). Conversely, the reverse MR analysis suggested that genetic susceptibility to PSC might not modify the risk of CHB (IVW OR = 1.004; 95% CI: 0.958-1.053, P = 0.866). Genetically proxied PBC and AIH exhibited no discernible causal association with CHB in the MR analysis using the IVW method (P = 0.583; P = 0.425). The MVMR analysis still indicated a decreased risk of CHB associated with PSC (OR = 0.853, P = 0.003). CONCLUSION: Our study elucidates a causal relationship between PSC and a diminished risk of CHB.

Urinary soluble CD163 is a putative non-invasive biomarker for primary sclerosing cholangitis.

Soluble CD163 (sCD163) is a selective marker of macrophages whose circulating levels have been found to be induced in patients with active inflammatory bowel disease (IBD). Urinary proteins are emerging as non-invasive diagnostic biomarkers, and here, sCD163 levels were measured in the urine of 18 controls and 63 patients with IBD by enzyme-linked immunosorbent assay. Urinary sCD163 levels did, however, not differentiate IBD patients from controls. Analysis of sCD163 in the serum of 51 of these patients did not show higher levels in IBD. Primary sclerosing cholangitis (PSC) is often associated with IBD, and sCD163 was higher in the urine of the 21 patients and in the serum of the 13 patients with PSC compared to patients with IBD. Of clinical relevance, urinary sCD163 levels were higher in PSC patients compared to those with other chronic liver diseases (n = 16), while serum sCD163 levels were comparable between the two groups. Serum sCD163 of IBD and PSC patients positively correlated with serum C-reactive protein. Serum creatinine and glomerular filtration rate, surrogate markers for renal function, did not significantly correlate with urinary or serum sCD163 levels in IBD or PSC patients. Moreover, urinary sCD163 was not related to fecal calprotectin levels whereas serum sCD163 of IBD patients showed a positive trend. PSC associated with IBD and PSC without underlying IBD had similar levels of urinary sCD163 while serum sCD163 tended to be higher in the latter group. In PSC patients, urinary sCD163 did not correlate with serum aminotransferase levels, gamma glutamyl transferase, alkaline phosphatase, bilirubin or the Model for End Stage Liver Disease score. Ursodeoxycholic acid was prescribed to our PSC patients and fecal levels of ursodeoxycholic acid and its conjugated forms were increased in PSC compared to IBD patients. Otherwise, fecal bile acid levels of IBD and PSC patients were almost identical, and were not correlated with urinary and serum sCD163 in PSC. In summary, our study identified urinary sCD163 as a potential biomarker for PSC.

Investigating the shared genetic architecture between primary sclerosing cholangitis and inflammatory bowel diseases: a Mendelian randomization study.

BACKGROUND: Several studies have found that primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) are closely associated. However, the direction and causality of their interactions remain unclear. Thus, this study employs Mendelian Randomization to explore whether there are causal associations of genetically predicted PSC with IBD. METHODS: Genetic variants associated with the genome-wide association study (GWAS) of PSC were used as instrumental variables. The statistics for IBD, including ulcerative colitis (UC), and Crohn's disease (CD) were derived from GWAS. Then, five methods were used to estimate the effects of genetically predicted PSC on IBD, including MR Egger, Weighted median (WM), Inverse variance weighted (IVW), Simple mode, and Weighted mode. Last, we also evaluated the pleiotropic effects, heterogeneity, and a leave-one-out sensitivity analysis that drives causal associations to confirm the validity of the analysis. RESULTS: Genetically predicted PSC was significantly associated with an increased risk of UC, according to the study (odds ratio [OR] IVW= 1.0014, P<0.05). However, none of the MR methods found significant causal evidence of genetically predicted PSC in CD (All P>0.05). The sensitivity analysis results showed that the causal effect estimations of genetically predicted PSC on IBD were robust, and there was no horizontal pleiotropy or statistical heterogeneity. CONCLUSIONS: Our study corroborated a causal association between genetically predicted PSC and UC but did not between genetically predicted PSC and CD. Then, we identification of shared SNPs for PSC and UC, including rs3184504, rs9858213, rs725613, rs10909839, and rs4147359. More animal experiments and clinical observational studies are required to further clarify the underlying mechanisms of PSC and IBD.

Role of PAR1 -506 deletion/insertion polymorphism in primary sclerosing cholangitis.

AIM: Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease characterized by inflammation of the intra- and extrahepatic bile ducts. Pathogenesis of PSC is still enigmatic but is likely to be multifactorial. Recently, we identified an interleukin-6 (IL-6)-dependent signal transducer and activator of transcription 3 (STAT3) activation in CD4+ TH1 and TH17 cells in PSC. The IL-6/STAT3 pathway was shown to be regulated by protease-activated receptor 1 (PAR1) contributing to inflammation. The role of the PAR1 -506 deletion/insertion (Del/Ins) polymorphism in PSC has not yet been investigated. METHODS: Two hundred eighty four PSC patients (200 patients with inflammatory bowel diseases [IBD] and 84 without IBD) and 309 healthy controls were genotyped for PAR1 rs11267092 (-506 Del/Ins -13 bp). Results were correlated with clinical characteristics and transplant-free survival. RESULTS: The frequency of PAR1 -506 Ins allele carriers (Del/Ins and Ins/Ins) was significantly higher in PSC patients (57.0%) compared to healthy controls (39.8%). Furthermore, carriers of PAR1 -506 Ins allele were more likely to have PSC than noncarriers (odds ratio 2.01; 95% confidence interval, 1.45-2.79). Patients with PSC carrying the PAR1 -506 Ins allele showed significantly higher alanine aminotransferase serum levels (p = 0.0357) and a trend toward shorter transplant-free survival time compared to noncarriers (8.9 ± 6.6 years vs. 10.5 ± 7.1 years; p = 0.076). CONCLUSIONS: Our study shows that PAR1 -506 Ins is significantly more frequent in people with PSC. As PAR1 -506 Ins allele carriers tended to have a shorter transplant-free survival, PAR1 might play a role in the development and course of PSC.

Risk of colorectal cancer in patients with primary sclerosing cholangitis and concomitant inflammatory bowel disease compared with primary sclerosing cholangitis only.

AIM: Primary sclerosing cholangitis (PSC) increases the risk of colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients; however, there is a paucity of literature to suggest PSC alone as an independent risk factor for CRC. We aimed to determine if PSC is an independent risk factor for CRC in a large tertiary care medical center. Optimizing screening intervals is of great importance, given the burden and risks associated with a lifetime of colonoscopy screening. METHODS: This retrospective cohort study consists of patients diagnosed with PSC preceding IBD (PSC-IBD) and PSC-only before January 6, 2023 from a large, tertiary, academic medical center. Patients diagnosed with IBD concurrently or before PSC were excluded to reduce IBD's impact on CRC risk. Demographic data and colonoscopy findings were collected and assessed. RESULTS: Overall, 140 patients from all NYU Langone Health clinical settings were included. Patients with PSC-IBD were more likely to be diagnosed with CRC (23.3% vs. 1.8%, p < 0.01) and either low-grade or uncharacterized dysplasia (16.7% vs. 0.0%, p < 0.01) compared with those with PSC-only. Among PSC-only patients, the estimated CRC risk was significantly elevated compared with that expected of the standard NYU Langone population (SIR 9.2, 95% CI 1.1, 33.2). CONCLUSIONS: Our study revealed a significantly heightened CRC risk in PSC-IBD patients compared with those with PSC-only. Importantly, individuals with PSC-only also face a greater CRC risk compared with the general population. Individuals with PSC-alone may require extended screening and surveillance colonoscopy intervals compared with those with PSC-IBD, yet still require more frequent monitoring than screening guidelines recommend for the general population.

Primary sclerosing cholangitis causally affects kidney function decline: A Mendelian randomization study.

BACKGROUND AND AIM: The causal linkage between primary sclerosing cholangitis (PSC) and kidney function is unexplored despite their potential for long-term detrimental effects on kidney function. METHODS: Two-sample summary-level Mendelian randomization (MR) study was conducted to identify the association between PSC and kidney function. The genetic variants were extracted from the PSC-specific multi-trait analyzed genome-wide association study (GWAS) of European ancestry. Summary-level data for kidney function traits, including estimated glomerular filtration rate (eGFR), annual eGFR decline, and chronic kidney disease (CKD), were obtained from the CKDGen consortium. Multiplicative random-effects inverse-variance weighted (MR-IVW), and a series of pleiotropy-robust analyses were performed to investigate the causal effects and ascertain their robustness. RESULTS: Significant causal associations between genetically predicted PSC and kidney function traits were identified. Genetically predicted PSC was associated with decreased log-transformed eGFR (MR-IVW; beta = -0.41%; standard error [SE] = 0.02%; P < 0.001), increased rate of annual eGFR decline (MR-IVW; beta = 2.43%; SE = 0.18%; P < 0.001), and higher risk of CKD (MR-IVW; odds ratio = 1.07; 95% confidence interval = 1.06-1.08; P < 0.001). The main findings were supported by pleiotropy-robust analysis, including MR-Egger with bootstrapped error and weighted median. CONCLUSIONS: Our study demonstrates that genetically predicted PSC is causally associated with kidney function impairment. Further studies are warranted to identify the underlying mechanisms.