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44 Publications visible to you, out of a total of 44
Comprehensive evaluation of phosphoproteomic-based kinase activity inference (preprint)

Abstract (Expand)

Kinases play a central role in regulating cellular processes, making their study essential for understanding cellular function and disease mechanisms. To investigate the regulatory state of a kinase, … numerous methods have been, and continue to be, developed to infer kinase activities from phosphoproteomics data. These methods usually rely on a set of kinase targets collected from various kinase-substrate libraries. However, only a small percentage of measured phosphorylation sites can usually be attributed to an upstream kinase in these libraries, limiting the scope of kinase activity inference. In addition, the inferred activities from different methods can vary making it crucial to evaluate them for accurate interpretation. Here, we present a comprehensive evaluation of kinase activity inference methods using multiple kinase-substrate libraries combined with different inference algorithms. Additionally, we try to overcome the coverage limitations for measured targets in kinase substrate libraries by adding predicted kinase-substrate interactions for activity inference. For the evaluation, in addition to classical cell-based perturbation experiments, we introduce a tumor-based benchmarking approach that utilizes multi-omics data to identify highly active or inactive kinases per tumor type. We show that while most computational algorithms perform comparably regardless of their complexity, the choice of kinase-substrate library can highly impact the inferred kinase activities. Hereby, manually curated libraries, particularly PhosphoSitePlus, demonstrate superior performance in recapitulating kinase activities from phosphoproteomics data. Additionally, in the tumor-based evaluation, adding predicted targets from NetworKIN further boosts the performance, while normalizing sites to host protein levels reduces kinase activity inference performance. We then showcase how kinase activity inference can help in characterizing the response to kinase inhibitors in different cell lines. Overall, the selection of reliable kinase activity inference methods is important in identifying deregulated kinases and novel drug targets. Finally, to facilitate the evaluation of novel methods in the future, we provide both benchmarking approaches in the R package benchmarKIN.

Authors: Sophia Müller-Dott, Eric J. Jaehnig, Khoi Pham Munchic, Wen Jiang, Tomer M. Yaron-Barir, Sara R. Savage, Martin Garrido-Rodriguez, Jared L. Johnson, Alessandro Lussana, Evangelia Petsalaki, Jonathan T. Lei, Aurélien Dugourd, Karsten Krug, Lewis C. Cantley, D. R. Mani, Bing Zhang, Julio Saez-Rodriguez

Date Published: 2nd Jul 2024

Publication Type: Journal

Thy‐1 restricts steatosis and liver fibrosis in steatotic liver disease

Abstract (Expand)

Abstract Background and Aims Steatotic liver disease (SLD) is generally considered to represent a hepatic manifestation of metabolic syndrome and includes a disease spectrum comprising isolated steatosis, …ludes a disease spectrum comprising isolated steatosis, metabolic dysfunction‐associated steatohepatitis, liver fibrosis and ultimately cirrhosis. A better understanding of the detailed underlying pathogenic mechanisms of this transition is crucial for the design of new and efficient therapeutic interventions. Thymocyte differentiation antigen (Thy‐1, also known as CD90) expression on fibroblasts controls central functions relevant to fibrogenesis, including proliferation, apoptosis, cytokine responsiveness, and myofibroblast differentiation. Methods The impact of Thy‐1 on the development of SLD and progression to fibrosis was investigated in high‐fat diet (HFD)‐induced SLD wild‐type and Thy‐1‐deficient mice. In addition, the serum soluble Thy‐1 (sThy‐1) concentration was analysed in patients with metabolic dysfunction‐associated SLD stratified according to steatosis, inflammation, or liver fibrosis using noninvasive markers. Results We demonstrated that Thy‐1 attenuates the development of fatty liver and the expression of profibrogenic genes in the livers of HFD‐induced SLD mice. Mechanistically, Thy‐1 directly inhibits the profibrotic activation of nonparenchymal liver cells. In addition, Thy‐1 prevents palmitic acid‐mediated amplification of the inflammatory response of myeloid cells, which might indirectly contribute to the pronounced development of liver fibrosis in Thy‐1‐deficient mice. Serum analysis of patients with metabolically associated steatotic liver disease syndrome revealed that sThy‐1 expression is correlated with liver fibrosis status, as assessed by liver stiffness, the Fib4 score, and the NAFLD fibrosis score. Conclusion Our data strongly suggest that Thy‐1 may function as a fibrosis‐protective factor in mouse and human SLD.

Authors: Valentin Blank, Thomas Karlas, Ulf Anderegg, Johannes Wiegand, Josi Arnold, Linnaeus Bundalian, Gabriela‐Diana Le Duc, Christiane Körner, Thomas Ebert, Anja Saalbach

Date Published: 4th May 2024

Publication Type: Journal

Lysis buffer selection guidance for mass spectrometry-based global proteomics including studies on the intersection of signal transduction and metabolism (preprint)

Abstract (Expand)

Prerequisite for a successful proteomics experiment is a high-quality lysis of the sample of interest, resulting in a large number of identified proteins as well as a high coverage of protein sequences. … Therefore, the choice of suitable lysis conditions is crucial. Many buffers were previously employed in proteomics studies, yet a comprehensive comparison of lysate preparation conditions was so far missing. In this study, we compared the efficiency of four commonly used lysis buffers, containing the agents NP40, SDS, urea or GdnHCl, in four different types of biological samples (suspension and adherent cell lines, primary mouse cells and mouse liver tissue). After liquid chromatography-mass spectrometry (LC-MS) measurement and MaxQuant analysis, we compared chromatograms, intensities, number of identified proteins and the localization of the identified proteins. Overall, SDS emerged as the most reliable reagent, ensuring stable performance and reproducibility across diverse samples. Furthermore, our data advocated for a dual-sample lysis approach, including that the resulting pellet is lysed again after the initial lysis with a urea lysis buffer and subsequently both lysates are combined for a single LC-MS run to maximize the proteome coverage. However, none of the investigated lysis buffers proved to be superior in every category, indicating that the lysis buffer of choice depends on the proteins of interest and on the biological question. Further, we demonstrated with our systematic studies the establishment of conditions that allows to perform global proteomics and affinity purification-based interactome characterization from the same lysate. In sum our results provide guidance for the best-suited lysis buffer for mass spectrometry-based proteomics depending on the question of interest.

Authors: Barbara Helm, Pauline Hansen, Li Lai, Luisa Schwarzmüller, Simone M. Clas, Annika Richter, Max Ruwolt, Fan Liu, Dario Frey, Lorenza A. D’Alessandro, Wolf-Dieter Lehmann, Marcel Schilling, Dominic Helm, Dorothea Fiedler, Ursula Klingmüller

Date Published: 21st Feb 2024

Publication Type: Journal

Basal MET phosphorylation is an indicator of hepatocyte dysregulation in liver disease

Abstract (Expand)

Abstract Chronic liver diseases are worldwide on the rise. Due to the rapidly increasing incidence, in particular in Western countries, metabolic dysfunction-associated steatotic liver disease (MASLD) …otic liver disease (MASLD) is gaining importance as the disease can develop into hepatocellular carcinoma. Lipid accumulation in hepatocytes has been identified as the characteristic structural change in MASLD development, but molecular mechanisms responsible for disease progression remained unresolved. Here, we uncover in primary hepatocytes from a preclinical model fed with a Western diet (WD) an increased basal MET phosphorylation and a strong downregulation of the PI3K-AKT pathway. Dynamic pathway modeling of hepatocyte growth factor (HGF) signal transduction combined with global proteomics identifies that an elevated basal MET phosphorylation rate is the main driver of altered signaling leading to increased proliferation of WD-hepatocytes. Model-adaptation to patient-derived hepatocytes reveal patient-specific variability in basal MET phosphorylation, which correlates with patient outcome after liver surgery. Thus, dysregulated basal MET phosphorylation could be an indicator for the health status of the liver and thereby inform on the risk of a patient to suffer from liver failure after surgery.

Authors: Sebastian Burbano De Lara, Svenja Kemmer, Ina Biermayer, Svenja Feiler, Artyom Vlasov, Lorenza A D’Alessandro, Barbara Helm, Christina Mölders, Yannik Dieter, Ahmed Ghallab, Jan G Hengstler, Christiane Körner, Madlen Matz-Soja, Christina Götz, Georg Damm, Katrin Hoffmann, Daniel Seehofer, Thomas Berg, Marcel Schilling, Jens Timmer, Ursula Klingmüller

Date Published: 12th Jan 2024

Publication Type: Journal

Tumour cells can escape antiproliferative pressure by interferon-β through immunoediting of interferon receptor expression

Abstract (Expand)

Abstract Type I interferons (IFNs) play a central role not only in innate immunity against viral infection, but also in the antitumour response, e.g. through a direct impact on cell proliferation. …act on cell proliferation. Particularly for cancer arising in the context of chronic inflammation, constant exposure to IFNs may constitute a strong selective pressure during tumour evolution. Expansion of neoplastic subclones resistant to the antiproliferative effects of IFNs may contribute to immunoediting of tumours, leading to more aggressive disease. Experimental evidence for this development of IFN-insensitivity has been scarce and its molecular mechanism is unclear. In this study we demonstrate that six weeks exposure of cells to IFN-β in vitro reduces their sensitivity to its antiproliferative effects, and that this phenotype was stable for up to four weeks. Furthermore, we observed substantial differences in cellular sensitivity to growth inhibition by IFN-β in a panel of ten different liver cancer cell lines, most prominently in a pair of highly dedifferentiated cell lines, and least in cells from well-differentiated tumours. In both, long-term IFN selection and in dedifferentiated tumour cell lines, we found IFNAR2 expression to be substantially reduced, suggesting the receptor complex to be a sensitive target amenable to immunoediting. Beyond new insights into possible molecular processes in tumour evolution, these findings might prove valuable for the development of biomarkers allowing to stratify tumours for their sensitivity to IFN treatment in the context of patient tailored therapies.

Authors: Felix Hiebinger, Aiste Kudulyte, Huanting Chi, Sebastian Burbano De Lara, Doroteja Ilic, Barbara Helm, Hendrik Welsch, Viet Loan Dao Thi, Ursula Klingmüller, Marco Binder

Date Published: 1st Dec 2023

Publication Type: Journal

Shear Wave Elastography for Assessing Liver Stiffness in HCV-Infected Kidney Transplant Recipients after Direct-Acting Antiviral Treatment: A Comparative Study with Magnetic Resonance Elastography

Abstract (Expand)

Hepatitis C virus (HCV) infection can lead to hepatic fibrosis. The advent of direct-acting antivirals (DAAs) has substantially improved sustained virological response (SVR) rates. In this context, … this context, kidney transplant recipients (KTRs) are of particular interest due to their higher HCV infection rates and uncertain renal excretion and bioavailability of DAAs. We investigated liver stiffness after DAA treatment in 15 HCV-infected KTRs using ultrasound shear wave elastography (SWE) in comparison with magnetic resonance elastography (MRE). KTRs were treated with DAAs (daclatasvir and sofosbuvir) for three months and underwent SWE at baseline, end of therapy (EOT), and 3 (EOT+3) and 12 months (EOT+12) after EOT. Fourteen patients achieved SVR12. Shear wave speed (SWS)—as a surrogate parameter for tissue stiffness—was substantially lower at all three post-therapeutic timepoints compared with baseline (EOT: −0.42 m/s, p < 0.01; CI = −0.75–−0.09, EOT+3: −0.43 m/s, p < 0.01; CI = −0.75–−0.11, and EOT+12: −0.52 m/s, p < 0.001; CI = −0.84–−0.19), suggesting liver regeneration after viral eradication and end of inflammation. Baseline SWS correlated positively with histopathological fibrosis scores (r = 0.48; CI = −0.11–0.85). Longitudinal results correlated moderately with APRI (r = 0.41; CI = 0.12–0.64) but not with FIB-4 scores (r = 0.12; CI = −0.19–0.41). Although higher on average, SWE-derived measurements correlated strongly with MRE (r = 0.64). In conclusion, SWE is suitable for non-invasive therapy monitoring in KTRs with HCV infection.

Authors: Salma Almutawakel, Fabian Halleck, Michael Dürr, Ulrike Grittner, Eva Schrezenmeier, Klemens Budde, Christian E. Althoff, Bernd Hamm, Ingolf Sack, Thomas Fischer, Stephan R. Marticorena Garcia

Date Published: 1st Dec 2023

Publication Type: Journal

Expanding the coverage of regulons from high-confidence prior knowledge for accurate estimation of transcription factor activities

Abstract (Expand)

Abstract Gene regulation plays a critical role in the cellular processes that underlie human health and disease. The regulatory relationship between transcription factors (TFs), key regulators of gene …s), key regulators of gene expression, and their target genes, the so called TF regulons, can be coupled with computational algorithms to estimate the activity of TFs. However, to interpret these findings accurately, regulons of high reliability and coverage are needed. In this study, we present and evaluate a collection of regulons created using the CollecTRI meta-resource containing signed TF–gene interactions for 1186 TFs. In this context, we introduce a workflow to integrate information from multiple resources and assign the sign of regulation to TF–gene interactions that could be applied to other comprehensive knowledge bases. We find that the signed CollecTRI-derived regulons outperform other public collections of regulatory interactions in accurately inferring changes in TF activities in perturbation experiments. Furthermore, we showcase the value of the regulons by examining TF activity profiles in three different cancer types and exploring TF activities at the level of single-cells. Overall, the CollecTRI-derived TF regulons enable the accurate and comprehensive estimation of TF activities and thereby help to interpret transcriptomics data.

Authors: Sophia Müller-Dott, Eirini Tsirvouli, Miguel Vazquez, Ricardo O Ramirez Flores, Pau Badia-i-Mompel, Robin Fallegger, Dénes Türei, Astrid Lægreid, Julio Saez-Rodriguez

Date Published: 10th Nov 2023

Publication Type: Journal

Insulin Determines Transforming Growth Factor β Effects on Hepatocyte Nuclear Factor 4α Transcription in Hepatocytes

Abstract (Expand)

Loss of hepatocyte nuclear factor 4α (HNF4α) expression is frequently observed in end-stage liver disease and associated with loss of vital liver functions, thus increasjng mortality. Loss of HNF4α … expression is mediated by inflammatory cytokines, such as transforming growth factor (TGF)-β. However, details of how HNF4α is suppressed are largely unknown to date. This study reports that TGF-β does not directly inhibit HNF4α but contributes to its transcriptional regulation by SMAD2/3 recruiting acetyltransferase CREB-binding protein/p300 to the HNF4α promoter. The recruitment of CREB-binding protein/p300 is indispensable for CCAAT/enhancer-binding protein α (C/EBPα) binding, another essential requirement for constitutive HNF4α expression in hepatocytes. Consistent with the in vitro observation, 67 of 98 patients with hepatic HNF4α express both phospho-SMAD2 and C/EBPα, whereas 22 patients without HNF4α expression lack either phospho-SMAD2 or C/EBPα. In contrast to the observed induction of HNF4α, SMAD2/3 inhibits C/EBPα transcription. Therefore, long-term TGF-β incubation results in C/EBPα depletion, which abrogates HNF4α expression. Intriguingly, SMAD2/3 inhibitory binding to the C/EBPα promoter is abolished by insulin. Two-thirds of patients without C/EBPα lack membrane glucose transporter type 2 expression in hepatocytes, indicating insulin resistance. Taken together, hepatic insulin sensitivity is essential for hepatic HNF4α expression in the condition of inflammation.

Authors: Rilu Feng, Chenhao Tong, Tao Lin, Hui Liu, Chen Shao, Yujia Li, Carsten Sticht, Kejia Kan, Xiaofeng Li, Rui Liu, Sai Wang, Shanshan Wang, Stefan Munker, Hanno Niess, Christoph Meyer, Roman Liebe, Matthias P. Ebert, Steven Dooley, Hua Wang, Huiguo Ding, Hong-Lei Weng

Date Published: 1st Oct 2023

Publication Type: Journal

Tumour cells can escape antiproliferative pressure by interferon-β through immunoediting of interferon receptor expression (preprint)

Abstract (Expand)

Type I interferons (IFNs) play a central role not only in innate immunity against viral infection, but also in the antitumour response. Apart from indirect immune-modulatory and anti-angiogenic effects, … they have direct impact on cell proliferation. Particularly for cancer arising in the context of chronic inflammation, constant exposure to IFNs may constitute a strong selective pressure during tumour evolution. Expansion of neoplastic subclones or -populations that developed resistance to the antiproliferative effects of IFNs might constitute an important contribution to immunoediting of the cancer cells leading to more aggressive and metastasising disease. Experimental evidence for this development of IFN-insensitivity has been scarce and its molecular mechanism is unclear. In this study we demonstrate that prolonged (six weeks) exposure of cells to IFN-β in vitro reduces their sensitivity to its antiproliferative effects, and that this phenotype was stable for up to four weeks. Furthermore, we observed substantial differences in cellular sensitivity to growth inhibition by IFN-β in a panel of ten different liver cancer cell lines of varying malignity. IFN-resistance was most prominent in a pair of highly dedifferentiated cell lines, and least in cells from well-differentiated tumours, fostering the hypothesis of IFN-driven immunoediting in advanced cancers. In both settings, long-term IFN selection in vitro as well as in dedifferentiated tumour cell lines, we found IFNAR expression to be substantially reduced, suggesting the receptor complex, in particular IFNAR2, to be a sensitive target amenable to immunoediting. Beyond new insights into possible molecular processes in tumour evolution, these findings might prove valuable for the development of biomarkers allowing to stratify tumours for their sensitivity to IFN treatment in the context of patient tailored therapies.

Authors: Felix Hiebinger, Aiste Kudulyte, Huanting Chi, Sebastian Burbano De Lara, Barbara Helm, Hendrik Welsch, Viet Loan Dao Thi, Ursula Klingmüller, Marco Binder

Date Published: 24th Aug 2023

Publication Type: Journal

TGF-β1 inhibits cholesterol metabolism in hepatocytes to facilitate cell death, EMT and signals for HSC activation.

Abstract (Expand)

Objective: Transforming growth factor-β1 (TGF-β1) plays important roles in chronic liver diseases, including metabolic dysfunction-associated steatotic liver disease (MASLD), which involves various …lves various biological processes including dysfunctional cholesterol metabolism contributing to progression to metabolic dysfunction-associated steatohepatitis (MASH) and hepatocellular carcinoma (HCC). However, how TGF-β1 signaling and cholesterol metabolism affects each other in MASLD is yet unknown. Design: Changes in transcription of genes associated with cholesterol metabolism were assessed by RNA-Seq of AML12 cells and mouse primary hepatocytes (MPH) treated with TGF-β1. Functional assays were performed on AML12 cells (untreated, TGF-β1 treated, or subjected to cholesterol enrichment (CE) or depletion (CD)), and on mice injected with adeno-associated virus 8 (AAV8)-Control/TGF-β1. Results: TGF-β1 inhibited mRNA expression of several cholesterol metabolism regulatory genes, including rate-limiting enzymes of cholesterol biosynthesis in AML12 cells, MPHs, and AAV8-TGF- β1-treated mice. Total cholesterol levels in AML12 cells, as well as lipid droplet accumulation in AML12 cells and AAV-treated mice were also reduced. Smad2/3 phosphorylation following 2 h TGF-β1 treatment persisted after CE or CD and was mildly increased following CD, while TGF-β1-mediated AKT phosphorylation (30 min) was inhibited by CE. Furthermore, CE protected AML12 cells from several effects mediated by 72 h incubation with TGF-β1, including EMT, actin polymerization, and apoptosis. CD mimicked the outcome of long term TGF-β1 administration, an effect that was blocked by an inhibitor of the type I TGF-β receptor. Additionally, the supernatant of CE- or CD-treated AML12 cells inhibited or promoted, respectively, the activation of LX-2 hepatic stellate cells. Conclusion: TGF-β1 inhibits cholesterol metabolism while cholesterol attenuates TGF-β1 downstream effects in hepatocytes.

Authors: Sai Wang, Frederik Link, Mei Han, Roman Liebe, Ye Yao, Seddik Hammad, Anne Dropmann, Roohi Chaudhary, Anastasia Asimakopoulos, Marinela Krizanac, Ralf Weiskirchen, Yoav I Henis, Marcelo Ehrlich, Matthias Ebert, Steven Dooley

Date Published: 15th Aug 2023

Publication Type: Journal

Hepatokine‐based identification of fibrotic NASH and improved risk stratification in a multicentre cohort of NAFLD patients

Abstract (Expand)

Abstract Background and Aims The presence of significant liver fibrosis associated with non‐alcoholic steatohepatitis (NASH) is regarded as the major prognostic factor in non‐alcoholic fatty liver …he major prognostic factor in non‐alcoholic fatty liver disease (NAFLD). Identification of patients at risk for NASH with significant fibrosis is therefore important. Although the established fibrosis score FIB‐4 is suitable to exclude advanced fibrosis, it does not allow the prediction of significant fibrosis in NAFLD patients. We therefore evaluated whether the hepatokine fibroblast growth factor 21 (FGF21), a regulator of glucose and lipid metabolism, might identify ‘at‐risk NASH’ in NAFLD. Methods FGF21 levels were assessed by enzyme‐linked immunosorbent assay in sera from an exploration ( n  = 137) and a validation ( n  = 88) cohort of biopsy‐proven NAFLD patients with different disease activity and fibrosis stages. In addition, we evaluated whether the use of FGF21 could improve risk stratification in NAFLD patients with low (<1.3) or intermediate (1.3–2.67) FIB‐4. Results FGF21 levels could significantly discriminate between NASH and non‐alcoholic fatty liver (NAFL) patients, even in the absence of diabetes. Moreover, patients with NASH and fibrosis ≥F2 showed significantly higher FGF21 levels compared to NAFLD patients without significant fibrosis. Significantly elevated FGF21 levels could even be detected in NAFLD patients with NASH and significant fibrosis despite low or intermediate FIB‐4. Conclusion Serological FGF21 detection might allow the identification of NAFLD patients at risk and improves patient stratification in combination with FIB‐4.

Authors: Martin Franck, Katharina John, Sherin Al Aoua, Monika Rau, Andreas Geier, Jörn M. Schattenberg, Heiner Wedemeyer, Klaus Schulze‐Osthoff, Heike Bantel

Date Published: 3rd Aug 2023

Publication Type: Journal

An integrative experimental and computational twin modeling approach to understand clonal dynamics in the normal liver

Abstract

Not specified

Authors: Dirk Drasdo, Jieling Zhao

Date Published: 1st Aug 2023

Publication Type: Journal

Myostatin is associated with the presence and development of acute-on-chronic liver failure

Abstract

Not specified

Authors: Astrid Ruiz-Margáin, Alessandra Pohlmann, Silke Lanzerath, Melanie Langheinrich, Alejandro Campos-Murguía, Berenice M. Román-Calleja, Robert Schierwagen, Sabine Klein, Frank Erhard Uschner, Maximilian Joseph Brol, Aldo Torre-Delgadillo, Nayelli C. Flores-García, Michael Praktiknjo, Ricardo U. Macías Rodríguez, Jonel Trebicka

Date Published: 1st Aug 2023

Publication Type: Journal

An integrated view of anti-inflammatory and antifibrotic targets for the treatment of NASH

Abstract

Not specified

Authors: Frank Tacke, Tobias Puengel, Rohit Loomba, Scott L. Friedman

Date Published: 1st Aug 2023

Publication Type: Journal

Development, validation, and prognostic evaluation of a risk score for long-term liver-related outcomes in the general population: a multicohort study

Abstract

Not specified

Authors: Miquel Serra-Burriel, Adrià Juanola, Feliu Serra-Burriel, Maja Thiele, Isabel Graupera, Elisa Pose, Guillem Pera, Ivica Grgurevic, Llorenç Caballeria, Salvatore Piano, Laurens van Kleef, Mathias Reichert, Dominique Roulot, Juan M Pericàs, Jörn M Schattenberg, Emmanuel A Tsochatztis, Indra Neil Guha, Montserrat Garcia-Retortillo, Rosario Hernández, Jordi Hoyo, Matilde Fuentes, Carmen Expósito, Alba Martínez, Patricia Such, Anita Madir, Sönke Detlefsen, Marta Tonon, Andrea Martini, Ann T Ma, Judith Pich, Eva Bonfill, Marta Juan, Anna Soria, Marta Carol, Jordi Gratacós-Ginès, Rosa M Morillas, Pere Toran, J M Navarrete, Antoni Torrejón, Céline Fournier, Anne Llorca, Anita Arslanow, Harry J de Koning, Fernando Cucchietti, Michael Manns, Phillip N Newsome, Rubén Hernáez, Alina Allen, Paolo Angeli, Robert J de Knegt, Tom H Karlsen, Peter Galle, Vincent Wai-Sun Wong, Núria Fabrellas, Laurent Castera, Aleksander Krag, Frank Lammert, Patrick S Kamath, Pere Ginès, Marifé Alvarez, Peter Andersen, Paolo Angeli, Alba Ardèvol, Anita Arslanow, Luca Beggiato, Zahia Ben Abdesselam, Lucy Bennett, Bajiha Boutouria, Alessandra Brocca, M. Teresa Broquetas, Llorenç Caballeria, Valeria Calvino, Judith Camacho, Aura Capdevila, Marta Carol, Laurent Castera, Marta Cervera, Fernando Cucchietti, Anna de Fuentes, Rob de Knegt, Harry J de Koning, Sonke Detlefsen, Alba Diaz, José Diéguez Bande, Vanessa Esnault, Núria Fabrellas, Josep Lluis Falcó, Rosa Fernández, Céline Fournier, Matilde Fuentes, Peter Galle, Edgar García, Montserrat García-Retortillo, Esther Garrido, Pere Ginès, Rosa Gordillo Medina, Jordi Gratacós-Ginès, Isabel Graupera, Ivica Grgurevic, Indra Neil Guha, Eva Guix, Johanne Kragh Hansen, Rebecca Harris, Elena Hernández Boluda, Rosario Hernández-Ibañez, Jordi Hoyo, Arfan Ikram, Simone Incicco, Mads Israelsen, Marta Juan, Adrià Juanola, Ralf Kaiser, Patrick S Kamath, Tom H Karlsen, Maria Kjærgaard, Marko Korenjak, Aleksander Krag, Marcin Krawczyk, Philippe Laboulaye, Irina Lambert, Frank Lammert, Simon Langkjær Sørensen, Cristina Laserna-Jiménez, Sonia Lazaro Pi, Elsa Ledain, Vincent Levy, Katrine Prier Lindvig, Anne Llorca, Vanessa Londoño, Guirec Loyer, Ann T. Ma, Anita Madir, Michael Manns, Denise Marshall, M. Lluïsa Martí, Sara Martínez, Ricard Martínez Sala, Roser Masa-Font, Jane Møller Jensen, Rosa M Morillas, Laura Muñoz, Ruth Nadal, Laura Napoleone, JM Navarrete, Phillip N Newsome, Vibeke Nielsen, Martina Pérez, Juan Manuel Pericás-Pulido, Salvatore Piano, Judit Pich, Elisa Pose, Judit Presas Escobet, Matthias Reichert, Carlota Riba, Dominique Roulot, Ana Belén Rubio, Maria Sánchez-Morata, Jörn Schattenberg, Miquel Serra-Burriel, Feliu Serra-Burriel, Louise Skovborg Just, Milan Sonneveld, Anna Soria, Christiane Stern, Patricia Such, Maja Thiele, Marta Tonon, Pere Toran, Antoni Torrejón, Emmanuel A Tsochatzis, Laurens van Kleef, Paulien van Wijngaarden, Vanessa Velázquez, Ana Viu, Susanne Nicole Weber, Tracey Wildsmith

Date Published: 1st Aug 2023

Publication Type: Journal

To TIPS or Not to TIPS in High Risk of Variceal Rebleeding and Acute-on-Chronic Liver Failure.

Abstract (Expand)

Variceal bleeding is a consequence of severe portal hypertension in patients with liver cirrhosis. Although the rate of bleeding has decreased over time, variceal bleeding in the presence of acute-on-chronic … liver failure (ACLF) carries a high risk of treatment failure and short-term mortality. Treatment and/or removal of precipitating events (mainly bacterial infection and alcoholic hepatitis) and decrease of portal pressure may improve outcome of patients with acute decompensation or ACLF. Transjugular intrahepatic portosystemic shunts (TIPSs), especially in the preemptive situation, have been found to efficiently control bleeding, prevent rebleeding, and reduce short-term mortality. Therefore, TIPS placement should be considered as an option in the management of ACLF patients with variceal bleeding.

Authors: W. Gu, M. Kimmann, W. Laleman, M. Praktiknjo, J. Trebicka

Date Published: 17th Jul 2023

Publication Type: Journal

Endoscopic Advances in Hepatology.

Abstract (Expand)

Endoscopy is and remains an indispensable tool in diagnosing and managing liver disease and its complications. Due to the progress in advanced endoscopy, endoscopy has become an alternative route for … many surgical, percutaneous, and angiographic interventions, not only as a backup tool when conventional interventions fail but increasingly as a first-line choice. The term endo-hepatology refers to the integration of advanced endoscopy in the practice of hepatology. Endoscopy is key in the diagnosis and management of esophageal and gastric varices, portal hypertensive gastropathy, and gastric antral vascular ectasia. Endoscopic ultrasound (EUS) can be used for the evaluation of the liver parenchyma, liver lesions, and surrounding tissues and vessels, including targeted biopsy and complemented with new software functions. Moreover, EUS can guide portal pressure gradient measurement, and assess and help manage complications of portal hypertension. It is crucial that each present-day hepatologist is aware of the (rapidly increasing) full spectrum of diagnostic and therapeutic tools that exist within this field. In this comprehensive review, we would like to discuss the current endo-hepatology spectrum, as well as future directions for endoscopy in hepatology.

Authors: E. Vanderschueren, J. Trebicka, W. Laleman

Date Published: 17th Jul 2023

Publication Type: Journal

Basal MET Phosphorylation is an Indicator of Hepatocyte Dysregulation in Liver Disease (preprint)

Abstract (Expand)

Chronic liver diseases are worldwide on the rise. Due to the rapidly increasing incidence, in particular in Western countries, Non-alcoholic fatty liver disease (NAFLD) is gaining importance as the … disease can develop into hepatocellular carcinoma. Lipid accumulation in hepatocytes has been identified as the characteristic structural change in NAFLD development, but molecular mechanisms responsible for disease progression remained unresolved. Here, we uncover in primary hepatocytes from a preclinical model fed with a Western diet (WD) a strong downregulation of the PI3K-AKT pathway and an upregulation of the MAPK pathway. Dynamic pathway modeling of hepatocyte growth factor (HGF) signal transduction combined with global proteomics identifies that an elevated basal MET phosphorylation rate is the main driver of altered signaling leading to increased proliferation of WD-hepatocytes. Model-adaptation to patient-derived hepatocytes reveal patient-specific variability in basal MET phosphorylation, which correlates with patient outcome after liver surgery. Thus, dysregulated basal MET phosphorylation could be an indicator for the health status of the liver and thereby inform on the risk of a patient to suffer from liver failure after surgery.

Authors: Sebastian Burbano De Lara, Svenja Kemmer, Ina Biermayer, Svenja Feiler, Artyom Vlasov, Lorenza D'Alessandro, Barbara Helm, Yannik Dieter, Ahmed Ghallab, Jan Hengstler, Professor Dr. med. Katrin Hoffmann, Marcel Schilling, Jens Timmer, Ursula Klingmüller

Date Published: 4th Jul 2023

Publication Type: Journal

Tolerance of repeated toxic injuries of murine livers is associated with steatosis and inflammation

Abstract (Expand)

Abstract The human liver has a remarkable capacity to regenerate and thus compensate over decades for fibrosis caused by toxic chemicals, drugs, alcohol, or malnutrition. To date, no protective mechanisms …rition. To date, no protective mechanisms have been identified that help the liver tolerate these repeated injuries. In this study, we revealed dysregulation of lipid metabolism and mild inflammation as protective mechanisms by studying longitudinal multi-omic measurements of liver fibrosis induced by repeated CCl 4 injections in mice ( n  = 45). Based on comprehensive proteomics, transcriptomics, blood- and tissue-level profiling, we uncovered three phases of early disease development—initiation, progression, and tolerance. Using novel multi-omic network analysis, we identified multi-level mechanisms that are significantly dysregulated in the injury-tolerant response. Public data analysis shows that these profiles are altered in human liver diseases, including fibrosis and early cirrhosis stages. Our findings mark the beginning of the tolerance phase as the critical switching point in liver response to repetitive toxic doses. After fostering extracellular matrix accumulation as an acute response, we observe a deposition of tiny lipid droplets in hepatocytes only in the Tolerant phase. Our comprehensive study shows that lipid metabolism and mild inflammation may serve as biomarkers and are putative functional requirements to resist further disease progression.

Authors: Seddik Hammad, Christoph Ogris, Amnah Othman, Pia Erdoesi, Wolfgang Schmidt-Heck, Ina Biermayer, Barbara Helm, Yan Gao, Weronika Piorońska, Christian H. Holland, Lorenza A. D’Alessandro, Carolina de la Torre, Carsten Sticht, Sherin Al Aoua, Fabian J. Theis, Heike Bantel, Matthias P. Ebert, Ursula Klingmüller, Jan G. Hengstler, Steven Dooley, Nikola S. Mueller

Date Published: 1st Jul 2023

Publication Type: Journal

Sublethal necroptosis signaling promotes inflammation and liver cancer

Abstract

Not specified

Authors: Mihael Vucur, Ahmed Ghallab, Anne T. Schneider, Arlind Adili, Mingbo Cheng, Mirco Castoldi, Michael T. Singer, Veronika Büttner, Leonie S. Keysberg, Lena Küsgens, Marlene Kohlhepp, Boris Görg, Suchira Gallage, Jose Efren Barragan Avila, Kristian Unger, Claus Kordes, Anne-Laure Leblond, Wiebke Albrecht, Sven H. Loosen, Carolin Lohr, Markus S. Jördens, Anne Babler, Sikander Hayat, David Schumacher, Maria T. Koenen, Olivier Govaere, Mark V. Boekschoten, Simone Jörs, Carlos Villacorta-Martin, Vincenzo Mazzaferro, Josep M. Llovet, Ralf Weiskirchen, Jakob N. Kather, Patrick Starlinger, Michael Trauner, Mark Luedde, Lara R. Heij, Ulf P. Neumann, Verena Keitel, Johannes G. Bode, Rebekka K. Schneider, Frank Tacke, Bodo Levkau, Twan Lammers, Georg Fluegen, Theodore Alexandrov, Amy L. Collins, Glyn Nelson, Fiona Oakley, Derek A. Mann, Christoph Roderburg, Thomas Longerich, Achim Weber, Augusto Villanueva, Andre L. Samson, James M. Murphy, Rafael Kramann, Fabian Geisler, Ivan G. Costa, Jan G. Hengstler, Mathias Heikenwalder, Tom Luedde

Date Published: 1st Jul 2023

Publication Type: Journal

Acute-On-Chronic Liver Failure: Current Interventional Treatment Options and Future Challenges.

Abstract (Expand)

Acute-on-chronic liver failure (ACLF) is a frequent complication in patients with liver cirrhosis that has high short-term mortality. It is characterized by acute decompensation (AD) of liver cirrhosis, … intra- and extrahepatic organ failure, and severe systemic inflammation (SI). In the recent past, several studies have investigated the management of this group of patients. Identification and treatment of precipitants of decompensation and ACLF play an important role, and management of the respective intra- and extrahepatic organ failures is essential. However, no specific treatment for ACLF has been established to date, and the only curative treatment option currently available for these patients is liver transplantation (LT). It has been shown that ACLF patients are at severe risk of waitlist mortality, and post-LT survival rates are high, making ACLF patients suitable candidates for LT. However, only a limited number of patients are eligible for LT due to related contraindications such as uncontrolled infections. In this case, bridging strategies (e.g., extracorporeal organ support systems) are required. Further therapeutic approaches have recently been developed and evaluated. Thus, this review focuses on current management and potential future treatment options.

Authors: M. Kimmann, J. Trebicka

Date Published: 26th Jun 2023

Publication Type: Journal

Efruxifermin, an investigational treatment for fibrotic or cirrhotic nonalcoholic steatohepatitis (NASH)

Abstract

Not specified

Authors: Tobias Puengel, Frank Tacke

Date Published: 3rd Jun 2023

Publication Type: Journal

Cholangiokines: undervalued modulators in the hepatic microenvironment

Abstract (Expand)

The biliary epithelial cells, also known as cholangiocytes, line the intra- and extrahepatic bile ducts, forming a barrier between intra- and extra-ductal environments. Cholangiocytes are mostly known …e mostly known to modulate bile composition and transportation. In hepatobiliary diseases, bile duct injury leads to drastic alterations in cholangiocyte phenotypes and their release of soluble mediators, which can vary depending on the original insult and cellular states (quiescence, senescence, or proliferation). The cholangiocyte-secreted cytokines (also termed cholangiokines) drive ductular cell proliferation, portal inflammation and fibrosis, and carcinogenesis. Hence, despite the previous consensus that cholangiocytes are bystanders in liver diseases, their diverse secretome plays critical roles in modulating the intrahepatic microenvironment. This review summarizes recent insights into the cholangiokines under both physiological and pathological conditions, especially as they occur during liver injury-regeneration, inflammation, fibrosis and malignant transformation processes.

Authors: Xiurong Cai, Frank Tacke, Adrien Guillot, Hanyang Liu

Date Published: 16th May 2023

Publication Type: Journal

The rationale and study design of two phase II trials examining the effects of BI 685,509, a soluble guanylyl cyclase activator, on clinically significant portal hypertension in patients with compensated cirrhosis.

Abstract (Expand)

BACKGROUND: Clinically significant portal hypertension (CSPH) drives cirrhosis-related complications (i.e. hepatic decompensation). Impaired nitric oxide (NO) bioavailability promotes sinusoidal … vasoconstriction, which is the initial pathomechanism of CSPH development. Activation of soluble guanylyl cyclase (sGC), a key downstream effector of NO, facilitates sinusoidal vasodilation, which in turn may improve CSPH. Two phase II studies are being conducted to assess the efficacy of the NO-independent sGC activator BI 685,509 in patients with CSPH due to various cirrhosis aetiologies. METHODS: The 1366.0021 trial (NCT05161481) is a randomised, placebo-controlled, exploratory study that will assess BI 685,509 (moderate or high dose) for 24 weeks in patients with CSPH due to alcohol-related liver disease. The 1366.0029 trial (NCT05282121) is a randomised, open-label, parallel-group, exploratory study that will assess BI 685,509 (high dose) alone in patients with hepatitis B or C virus infection or non-alcoholic steatohepatitis (NASH) and in combination with 10 mg empagliflozin in patients with NASH and type 2 diabetes mellitus for 8 weeks. The 1366.0021 trial will enrol 105 patients, and the 1366.0029 trial will enrol 80 patients. In both studies, the primary endpoint is the change from baseline in hepatic venous pressure gradient (HVPG) until the end of treatment (24 or 8 weeks, respectively). Secondary endpoints include the proportion of patients with an HVPG reduction of > 10% from baseline, the development of decompensation events and the change from baseline in HVPG after 8 weeks in the 1366.0021 trial. In addition, the trials will assess changes in liver and spleen stiffness by transient elastography, changes in hepatic and renal function and the tolerability of BI 685,509. DISCUSSION: These trials will enable the assessment of the short-term (8 weeks) and longer-term (24 weeks) effects and safety of sGC activation by BI 685,509 on CSPH due to various cirrhosis aetiologies. The trials will use central readings of the diagnostic gold standard HVPG for the primary endpoint, as well as changes in established non-invasive biomarkers, such as liver and spleen stiffness. Ultimately, these trials will provide key information for developing future phase III trials. TRIAL REGISTRATION: 1366.0021: EudraCT no. 2021-001,285-38; ClinicalTrials.gov NCT05161481. Registered on 17 December 2021, https://www. CLINICALTRIALS: gov/ct2/show/NCT05161481 . 1366.0029: EudraCT no. 2021-005,171-40; ClinicalTrials.gov NCT05282121. Registered on 16 March 2022, https://www. CLINICALTRIALS: gov/ct2/show/NCT05282121 .

Authors: T. Reiberger, A. Berzigotti, J. Trebicka, J. Ertle, I. Gashaw, R. Swallow, A. Tomisser

Date Published: 24th Apr 2023

Publication Type: Journal

Serum CXCL5 Detects Early Hepatocellular Carcinoma and Indicates Tumor Progression.

Abstract (Expand)

Chemokines or chemotactic cytokines play a pivotal role in the immune pathogenesis of liver cirrhosis and hepatocellular carcinoma (HCC). Nevertheless, comprehensive cytokine profiling data across … different etiologies of liver diseases are lacking. Chemokines might serve as diagnostic and prognostic biomarkers. In our study, we analyzed serum concentrations of 12 inflammation-related chemokines in a cohort of patients (n = 222) with cirrhosis of different etiologies and/or HCC. We compared 97 patients with cirrhosis and treatment-naive HCC to the chemokine profile of 125 patients with cirrhosis but confirmed absence of HCC. Nine out of twelve chemokines were significantly elevated in sera of cirrhotic patients with HCC compared to HCC-free cirrhosis controls (CCL2, CCL11, CCL17, CCL20, CXCL1, CXCL5, CXCL9, CXCL10, CXCL11). Among those, CXCL5, CXCL9, CXCL10, and CXCL11 were significantly elevated in patients with early HCC according to the Barcelona Clinic Liver Cancer (BCLC) stages 0/A compared to cirrhotic controls without HCC. In patients with HCC, CXCL5 serum levels were associated with tumor progression, and levels of CCL20 and CXCL8 with macrovascular invasion. Importantly, our study identified CXCL5, CXCL9, and CXCL10 as universal HCC markers, independent from underlying etiology of cirrhosis. In conclusion, regardless of the underlying liver disease, patients with cirrhosis share an HCC-specific chemokine profile. CXCL5 may serve as a diagnostic biomarker in cirrhotic patients for early HCC detection as well as for tumor progression.

Authors: A. Laschtowitz, J. Lambrecht, T. Puengel, F. Tacke, R. Mohr

Date Published: 10th Mar 2023

Publication Type: Journal

Genetic variation in TERT modifies the risk of hepatocellular carcinoma in alcohol-related cirrhosis: results from a genome-wide case-control study

Abstract (Expand)

Objective Hepatocellular carcinoma (HCC) often develops in patients with alcohol-related cirrhosis at an annual risk of up to 2.5%. Some host genetic risk factors have been identified but do not account …tors have been identified but do not account for the majority of the variance in occurrence. This study aimed to identify novel susceptibility loci for the development of HCC in people with alcohol related cirrhosis. Design Patients with alcohol-related cirrhosis and HCC (cases: n=1214) and controls without HCC (n=1866), recruited from Germany, Austria, Switzerland, Italy and the UK, were included in a two-stage genome-wide association study using a case–control design. A validation cohort of 1520 people misusing alcohol but with no evidence of liver disease was included to control for possible association effects with alcohol misuse. Genotyping was performed using the InfiniumGlobal Screening Array (V.24v2, Illumina) and the OmniExpress Array (V.24v1-0a, Illumina). Results Associations with variants rs738409 in PNPLA3 and rs58542926 in TM6SF2 previously associated with an increased risk of HCC in patients with alcohol-related cirrhosis were confirmed at genome-wide significance. A novel locus rs2242652(A) in TERT (telomerase reverse transcriptase) was also associated with a decreased risk of HCC, in the combined meta-analysis, at genome-wide significance (p=6.41×10 −9 , OR=0.61 (95% CI 0.52 to 0.70). This protective association remained significant after correction for sex, age, body mass index and type 2 diabetes (p=7.94×10 −5 , OR=0.63 (95% CI 0.50 to 0.79). Carriage of rs2242652(A) in TERT was associated with an increased leucocyte telomere length (p=2.12×10 −44 ). Conclusion This study identifies rs2242652 in TERT as a novel protective factor for HCC in patients with alcohol-related cirrhosis.

Authors: Stephan Buch, Hamish Innes, Philipp Ludwig Lutz, Hans Dieter Nischalke, Jens U Marquardt, Janett Fischer, Karl Heinz Weiss, Jonas Rosendahl, Astrid Marot, Marcin Krawczyk, Markus Casper, Frank Lammert, Florian Eyer, Arndt Vogel, Silke Marhenke, Johann von Felden, Rohini Sharma, Stephen Rahul Atkinson, Andrew McQuillin, Jacob Nattermann, Clemens Schafmayer, Andre Franke, Christian Strassburg, Marcella Rietschel, Heidi Altmann, Stefan Sulk, Veera Raghavan Thangapandi, Mario Brosch, Carolin Lackner, Rudolf E Stauber, Ali Canbay, Alexander Link, Thomas Reiberger, Mattias Mandorfer, Georg Semmler, Bernhard Scheiner, Christian Datz, Stefano Romeo, Stefano Ginanni Corradini, William Lucien Irving, Joanne R Morling, Indra Neil Guha, Eleanor Barnes, M Azim Ansari, Jocelyn Quistrebert, Luca Valenti, Sascha A Müller, Marsha Yvonne Morgan, Jean-François Dufour, Jonel Trebicka, Thomas Berg, Pierre Deltenre, Sebastian Mueller, Jochen Hampe, Felix Stickel

Date Published: 5th Jan 2023

Publication Type: Journal

The Diagnostic Approach towards Combined Hepatocellular-Cholangiocarcinoma—State of the Art and Future Perspectives

Abstract (Expand)

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer which displays clinicopathologic features of both hepatocellular (HCC) and cholangiocellular carcinoma (CCA). The …oma (CCA). The similarity to HCC and CCA makes the diagnostic workup particularly challenging. Alpha-fetoprotein (AFP) and carbohydrate antigen 19-9 (CA 19-9) are blood tumour markers related with HCC and CCA, respectively. They can be used as diagnostic markers in cHCC-CCA as well, albeit with low sensitivity. The imaging features of cHCC-CCA overlap with those of HCC and CCA, dependent on the predominant histopathological component. Using the Liver Imaging and Reporting Data System (LI-RADS), as many as half of cHCC-CCAs may be falsely categorised as HCC. This is especially relevant since the diagnosis of HCC may be made without histopathological confirmation in certain cases. Thus, in instances of diagnostic uncertainty (e.g., simultaneous radiological HCC and CCA features, elevation of CA 19-9 and AFP, HCC imaging features and elevated CA 19-9, and vice versa) multiple image-guided core needle biopsies should be performed and analysed by an experienced pathologist. Recent advances in the molecular characterisation of cHCC-CCA, innovative diagnostic approaches (e.g., liquid biopsies) and methods to analyse multiple data points (e.g., clinical, radiological, laboratory, molecular, histopathological features) in an all-encompassing way (e.g., by using artificial intelligence) might help to address some of the existing diagnostic challenges.

Authors: Johannes Eschrich, Zuzanna Kobus, Dominik Geisel, Sebastian Halskov, Florian Roßner, Christoph Roderburg, Raphael Mohr, Frank Tacke

Date Published: 2023

Publication Type: Journal

Mapping the hepatic immune landscape identifies monocytic macrophages as key drivers of steatohepatitis and cholangiopathy progression

Abstract

Not specified

Authors: Adrien Guillot, Marc Winkler, Milessa Silva Afonso, Abhishek Aggarwal, David Lopez, Hilmar Berger, Marlene S. Kohlhepp, Hanyang Liu, Burcin Özdirik, Johannes Eschrich, Jing Ma, Moritz Peiseler, Felix Heymann, Swetha Pendem, Sangeetha Mahadevan, Bin Gao, Lauri Diehl, Ruchi Gupta, Frank Tacke

Date Published: 2023

Publication Type: Journal

Hepatic C-X-C chemokine receptor type 6–expressing innate lymphocytes limit detrimental myeloid hyperactivation in acute liver injury

Abstract

Not specified

Authors: Felix Heymann, Jana C. Mossanen, Moritz Peiseler, Patricia M. Niemietz, Bruna Araujo David, Oliver Krenkel, Anke Liepelt, Matheus Batista Carneiro, Marlene S. Kohlhepp, Paul Kubes, Frank Tacke

Date Published: 2023

Publication Type: Journal

In Vitro Models for the Study of Liver Biology and Diseases: Advances and Limitations

Abstract

Not specified

Authors: Savneet Kaur, Srivatsan Kidambi, Martí Ortega-Ribera, Le Thi Thanh Thuy, Natalia Nieto, Victoria C. Cogger, Wei-Fen Xie, Frank Tacke, Jordi Gracia-Sancho

Date Published: 2023

Publication Type: Journal

Therapeutic modulation of the liver immune microenvironment

Abstract

Not specified

Authors: Herbert Tilg, Timon E. Adolph, Frank Tacke

Date Published: 2023

Publication Type: Journal

The Multifaceted Roles of Macrophages in NAFLD Pathogenesis

Abstract

Not specified

Authors: Joscha Vonderlin, Triantafyllos Chavakis, Michael Sieweke, Frank Tacke

Date Published: 2023

Publication Type: Journal

Guided interactive image segmentation using machine learning and color-based image set clustering.

Abstract (Expand)

MOTIVATION: Over the last decades, image processing and analysis have become one of the key technologies in systems biology and medicine. The quantification of anatomical structures and dynamic processes … in living systems is essential for understanding the complex underlying mechanisms and allows, i.e. the construction of spatio-temporal models that illuminate the interplay between architecture and function. Recently, deep learning significantly improved the performance of traditional image analysis in cases where imaging techniques provide large amounts of data. However, if only a few images are available or qualified annotations are expensive to produce, the applicability of deep learning is still limited. RESULTS: We present a novel approach that combines machine learning-based interactive image segmentation using supervoxels with a clustering method for the automated identification of similarly colored images in large image sets which enables a guided reuse of interactively trained classifiers. Our approach solves the problem of deteriorated segmentation and quantification accuracy when reusing trained classifiers which is due to significant color variability prevalent and often unavoidable in biological and medical images. This increase in efficiency improves the suitability of interactive segmentation for larger image sets, enabling efficient quantification or the rapid generation of training data for deep learning with minimal effort. The presented methods are applicable for almost any image type and represent a useful tool for image analysis tasks in general. AVAILABILITY AND IMPLEMENTATION: The presented methods are implemented in our image processing software TiQuant which is freely available at tiquant.hoehme.com. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Authors: A. Friebel, T. Johann, D. Drasdo, S. Hoehme

Date Published: 30th Sep 2022

Publication Type: Journal

Erythropoietin-driven dynamic proteome adaptations during erythropoiesis prevent iron overload in the developing embryo.

Abstract (Expand)

Erythropoietin (Epo) ensures survival and proliferation of colony-forming unit erythroid (CFU-E) progenitor cells and their differentiation to hemoglobin-containing mature erythrocytes. A lack of … Epo-induced responses causes embryonic lethality, but mechanisms regulating the dynamic communication of cellular alterations to the organismal level remain unresolved. By time-resolved transcriptomics and proteomics, we show that Epo induces in CFU-E cells a gradual transition from proliferation signature proteins to proteins indicative for differentiation, including heme-synthesis enzymes. In the absence of the Epo receptor (EpoR) in embryos, we observe a lack of hemoglobin in CFU-E cells and massive iron overload of the fetal liver pointing to a miscommunication between liver and placenta. A reduction of iron-sulfur cluster-containing proteins involved in oxidative phosphorylation in these embryos leads to a metabolic shift toward glycolysis. This link connecting erythropoiesis with the regulation of iron homeostasis and metabolic reprogramming suggests that balancing these interactions is crucial for protection from iron intoxication and for survival.

Authors: S. Chakraborty, G. Andrieux, P. Kastl, L. Adlung, S. Altamura, M. E. Boehm, L. E. Schwarzmuller, Y. Abdullah, M. C. Wagner, B. Helm, H. J. Grone, W. D. Lehmann, M. Boerries, H. Busch, M. U. Muckenthaler, M. Schilling, U. Klingmuller

Date Published: 20th Sep 2022

Publication Type: Journal

Investigation of Radiotracer Metabolic Stability In Vitro with CYP-Overexpressing Hepatoma Cell Lines.

Abstract (Expand)

The characterization of novel radiotracers toward their metabolic stability is an essential part of their development. While in vitro methods such as liver microsome assays or ex vivo blood or tissue … samples provide information on overall stability, little or no information is obtained on cytochrome P450 (CYP) enzyme and isoform-specific contribution to the metabolic fate of individual radiotracers. Herein, we investigated recently established CYP-overexpressing hepatoblastoma cell lines (HepG2) for their suitability to study the metabolic stability of radiotracers in general and to gain insight into CYP isoform specificity. Wildtype HepG2 and CYP1A2-, CYP2C19-, and CYP3A4-overexpressing HepG2 cells were incubated with radiotracers, and metabolic turnover was analyzed. The optimized protocol, covering cell seeding in 96-well plates and analysis of supernatant by radio thin-layer-chromatography for higher throughput, was transferred to the evaluation of three (18)F-labeled celecoxib-derived cyclooxygenase-2 inhibitors (coxibs). These investigations revealed time-dependent degradation of the intact radiotracers, as well as CYP isoform- and substrate-specific differences in their metabolic profiles. HepG2 CYP2C19 proved to be the cell line showing the highest metabolic turnover for each radiotracer studied here. Comparison with human and murine liver microsome assays showed good agreement with the human metabolite profile obtained by the HepG2 cell lines. Therefore, CYP-overexpressing HepG2 cells provide a good complement for assessing the metabolic stability of radiotracers and allow the analysis of the CYP isoform-specific contribution to the overall radiotracer metabolism.

Authors: S. Lemm, S. Kohler, R. Wodtke, F. Jung, J. H. Kupper, J. Pietzsch, M. Laube

Date Published: 7th Aug 2022

Publication Type: Journal

Hepatic Expression of the Na+-Taurocholate Cotransporting Polypeptide Is Independent from Genetic Variation

Abstract (Expand)

The hepatic Na+-taurocholate cotransporting polypeptide NTCP/SLC10A1 is important for the uptake of bile salts and selected drugs. Its inhibition results in increased systemic bile salt concentrations. …oncentrations. NTCP is also the entry receptor for the hepatitis B/D virus. We investigated interindividual hepatic SLC10A1/NTCP expression using various omics technologies. SLC10A1/NTCP mRNA expression/protein abundance was quantified in well-characterized 143 human livers by real-time PCR and LC-MS/MS-based targeted proteomics. Genome-wide SNP arrays and SLC10A1 next-generation sequencing were used for genomic analyses. SLC10A1 DNA methylation was assessed through MALDI-TOF MS. Transcriptomics and untargeted metabolomics (UHPLC-Q-TOF-MS) were correlated to identify NTCP-related metabolic pathways. SLC10A1 mRNA and NTCP protein levels varied 44-fold and 10.4-fold, respectively. Non-genetic factors (e.g., smoking, alcohol consumption) influenced significantly NTCP expression. Genetic variants in SLC10A1 or other genes do not explain expression variability which was validated in livers (n = 50) from The Cancer Genome Atlas. The identified two missense SLC10A1 variants did not impair transport function in transfectants. Specific CpG sites in SLC10A1 as well as single metabolic alterations and pathways (e.g., peroxisomal and bile acid synthesis) were significantly associated with expression. Inter-individual variability of NTCP expression is multifactorial with the contribution of clinical factors, DNA methylation, transcriptional regulation as well as hepatic metabolism, but not genetic variation.

Authors: Roman Tremmel, Anne T. Nies, Barbara A. C. van Eijck, Niklas Handin, Mathias Haag, Stefan Winter, Florian A. Büttner, Charlotte Kölz, Franziska Klein, Pascale Mazzola, Ute Hofmann, Kathrin Klein, Per Hoffmann, Markus M. Nöthen, Fabienne Z. Gaugaz, Per Artursson, Matthias Schwab, Elke Schaeffeler

Date Published: 1st Jul 2022

Publication Type: Journal

Deciphering signal transduction networks in the liver by mechanistic mathematical modelling

Abstract (Expand)

In health and disease, liver cells are continuously exposed to cytokines and growth factors. While individual signal transduction pathways induced by these factors were studied in great detail, the … cellular responses induced by repeated or combined stimulations are complex and less understood. Growth factor receptors on the cell surface of hepatocytes were shown to be regulated by receptor interactions, receptor trafficking and feedback regulation. Here, we exemplify how mechanistic mathematical modelling based on quantitative data can be employed to disentangle these interactions at the molecular level. Crucial is the analysis at a mechanistic level based on quantitative longitudinal data within a mathematical framework. In such multi-layered information, step-wise mathematical modelling using submodules is of advantage, which is fostered by sharing of standardized experimental data and mathematical models. Integration of signal transduction with metabolic regulation in the liver and mechanistic links to translational approaches promise to provide predictive tools for biology and personalized medicine.

Authors: Lorenza A. D’Alessandro, Ursula Klingmüller, Marcel Schilling

Date Published: 30th Jun 2022

Publication Type: Journal

Fibrogenic Pathways in Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD).

Abstract (Expand)

The prevalence of nonalcoholic fatty liver disease (NAFLD), recently also re-defined as metabolic dysfunction associated fatty liver disease (MAFLD), is rapidly increasing, affecting ~25% of the world … population. MALFD/NAFLD represents a spectrum of liver pathologies including the more benign hepatic steatosis and the more advanced non-alcoholic steatohepatitis (NASH). NASH is associated with enhanced risk for liver fibrosis and progression to cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) activation underlies NASH-related fibrosis. Here, we discuss the profibrogenic pathways, which lead to HSC activation and fibrogenesis, with a particular focus on the intercellular hepatocyte-HSC and macrophage-HSC crosstalk.

Authors: P. Subramanian, J. Hampe, F. Tacke, T. Chavakis

Date Published: 23rd Jun 2022

Publication Type: Journal

Hepatic Hedgehog Signaling Participates in the Crosstalk between Liver and Adipose Tissue in Mice by Regulating FGF21

Abstract (Expand)

The Hedgehog signaling pathway regulates many processes during embryogenesis and the homeostasis of adult organs. Recent data suggest that central metabolic processes and signaling cascades in the liver …s in the liver are controlled by the Hedgehog pathway and that changes in hepatic Hedgehog activity also affect peripheral tissues, such as the reproductive organs in females. Here, we show that hepatocyte-specific deletion of the Hedgehog pathway is associated with the dramatic expansion of adipose tissue in mice, the overall phenotype of which does not correspond to the classical outcome of insulin resistance-associated diabetes type 2 obesity. Rather, we show that alterations in the Hedgehog signaling pathway in the liver lead to a metabolic phenotype that is resembling metabolically healthy obesity. Mechanistically, we identified an indirect influence on the hepatic secretion of the fibroblast growth factor 21, which is regulated by a series of signaling cascades that are directly transcriptionally linked to the activity of the Hedgehog transcription factor GLI1. The results of this study impressively show that the metabolic balance of the entire organism is maintained via the activity of morphogenic signaling pathways, such as the Hedgehog cascade. Obviously, several pathways are orchestrated to facilitate liver metabolic status to peripheral organs, such as adipose tissue.

Authors: Fritzi Ott, Christiane Körner, Kim Werner, Martin Gericke, Ines Liebscher, Donald Lobsien, Silvia Radrezza, Andrej Shevchenko, Ute Hofmann, Jürgen Kratzsch, Rolf Gebhardt, Thomas Berg, Madlen Matz-Soja

Date Published: 1st May 2022

Publication Type: Journal

MSPypeline: a python package for streamlined data analysis of mass spectrometry-based proteomics

Abstract (Expand)

Abstract Summary Mass spectrometry-based proteomics is increasingly employed in biology and medicine. To generate reliable information from large datasets and ensure comparability of results, it is …rge datasets and ensure comparability of results, it is crucial to implement and standardize the quality control of the raw data, the data processing steps and the statistical analyses. MSPypeline provides a platform for importing MaxQuant output tables, generating quality control reports, data preprocessing including normalization and performing exploratory analyses by statistical inference plots. These standardized steps assess data quality, provide customizable figures and enable the identification of differentially expressed proteins to reach biologically relevant conclusions. Availability and implementation The source code is available under the MIT license at https://github.com/siheming/mspypeline with documentation at https://mspypeline.readthedocs.io. Benchmark mass spectrometry data are available on ProteomeXchange (PXD025792). Supplementary information Supplementary data are available at Bioinformatics Advances online.

Authors: Simon Heming, Pauline Hansen, Artyom Vlasov, Florian Schwörer, Stephen Schaumann, Paulina Frolovaitė, Wolf-Dieter Lehmann, Jens Timmer, Marcel Schilling, Barbara Helm, Ursula Klingmüller

Date Published: 2022

Publication Type: Journal

The rs429358 Locus in Apolipoprotein E Is Associated With Hepatocellular Carcinoma in Patients With Cirrhosis

Abstract (Expand)

The host genetic background for hepatocellular carcinoma (HCC) is incompletely understood. We aimed to determine if four germline genetic polymorphisms, rs429358 in apolipoprotein E ( APOE ), rs2642438 …rotein E ( APOE ), rs2642438 in mitochondrial amidoxime reducing component 1 ( MARC1 ), rs2792751 in glycerol‐3‐phosphate acyltransferase ( GPAM ), and rs187429064 in transmembrane 6 superfamily member 2 ( TM6SF2 ), previously associated with progressive alcohol‐related and nonalcoholic fatty liver disease, are also associated with HCC. Four HCC case‐control data sets were constructed, including two mixed etiology data sets (UK Biobank and FinnGen); one hepatitis C virus (HCV) cohort (STOP‐HCV), and one alcohol‐related HCC cohort (Dresden HCC). The frequency of each variant was compared between HCC cases and cirrhosis controls (i.e., patients with cirrhosis without HCC). Population controls were also considered. Odds ratios (ORs) associations were calculated using logistic regression, adjusting for age, sex, and principal components of genetic ancestry. Fixed‐effect meta‐analysis was used to determine the pooled effect size across all data sets. Across four case‐control data sets, 2,070 HCC cases, 4,121 cirrhosis controls, and 525,779 population controls were included. The rs429358:C allele ( APOE ) was significantly less frequent in HCC cases versus cirrhosis controls (OR, 0.71; 95% confidence interval [CI], 0.61‐0.84; P  = 2.9 × 10 −5 ). Rs187429064:G ( TM6SF2 ) was significantly more common in HCC cases versus cirrhosis controls and exhibited the strongest effect size (OR, 2.03; 95% CI, 1.45‐2.86; P  = 3.1 × 10 −6 ). In contrast, rs2792751:T ( GPAM ) was not associated with HCC (OR, 1.01; 95% CI, 0.90‐1.13; P  = 0.89), whereas rs2642438:A ( MARC1 ) narrowly missed statistical significance (OR, 0.91; 95% CI, 0.84‐1.00; P  = 0.043). Conclusion: This study associates carriage of rs429358:C ( APOE ) with a reduced risk of HCC in patients with cirrhosis. Conversely, carriage of rs187429064:G in TM6SF2 is associated with an increased risk of HCC in patients with cirrhosis.

Authors: Hamish Innes, Hans Dieter Nischalke, Indra Neil Guha, Karl Heinz Weiss, Will Irving, Daniel Gotthardt, Eleanor Barnes, Janett Fischer, M. Azim Ansari, Jonas Rosendahl, Shang‐Kuan Lin, Astrid Marot, Vincent Pedergnana, Markus Casper, Jennifer Benselin, Frank Lammert, John McLauchlan, Philip L. Lutz, Victoria Hamill, Sebastian Mueller, Joanne R. Morling, Georg Semmler, Florian Eyer, Johann von Felden, Alexander Link, Arndt Vogel, Jens U. Marquardt, Stefan Sulk, Jonel Trebicka, Luca Valenti, Christian Datz, Thomas Reiberger, Clemens Schafmayer, Thomas Berg, Pierre Deltenre, Jochen Hampe, Felix Stickel, Stephan Buch

Date Published: 2022

Publication Type: Journal

Cell-to-cell variability in JAK2/STAT5 pathway components and cytoplasmic volumes defines survival threshold in erythroid progenitor cells.

Abstract (Expand)

Survival or apoptosis is a binary decision in individual cells. However, at the cell-population level, a graded increase in survival of colony-forming unit-erythroid (CFU-E) cells is observed upon … stimulation with erythropoietin (Epo). To identify components of Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5) signal transduction that contribute to the graded population response, we extended a cell-population-level model calibrated with experimental data to study the behavior in single cells. The single-cell model shows that the high cell-to-cell variability in nuclear phosphorylated STAT5 is caused by variability in the amount of Epo receptor (EpoR):JAK2 complexes and of SHP1, as well as the extent of nuclear import because of the large variance in the cytoplasmic volume of CFU-E cells. 24-118 pSTAT5 molecules in the nucleus for 120 min are sufficient to ensure cell survival. Thus, variability in membrane-associated processes is sufficient to convert a switch-like behavior at the single-cell level to a graded population-level response.

Authors: L. Adlung, P. Stapor, C. Tonsing, L. Schmiester, L. E. Schwarzmuller, L. Postawa, D. Wang, J. Timmer, U. Klingmuller, J. Hasenauer, M. Schilling

Date Published: 10th Aug 2021

Publication Type: Journal

Cell atlas of the regenerating human liver after portal vein embolization

Abstract (Expand)

The liver has the remarkable capacity to regenerate. In the clinic, this capacity can be induced by portal vein embolization (PVE), which redirects portal blood flow resulting in liver hypertrophy in …pertrophy in locations with increased blood supply, and atrophy of embolized segments. Here we apply single-cell and single-nucleus transcriptomics on healthy, hypertrophied, and atrophied patient-derived liver samples to explore cell states in the liver during regeneration. We first establish an atlas of cell subtypes from the healthy human liver using fresh and frozen tissues, and then compare post-PVE samples with their reference counterparts. We find that PVE alters portal-central zonation of hepatocytes and endothelial cells. Embolization upregulates expression programs associated with development, cellular adhesion and inflammation across cell types. Analysis of interlineage crosstalk revealed key roles for immune cells in modulating regenerating tissue responses. Altogether, our data provides a rich resource for understanding homeostatic mechanisms arising during human liver regeneration and degeneration.

Authors: Agnieska Brazovskaja, Tomás Gomes, Christiane Körner, Zhisong He, Theresa Schaffer, Julian Connor Eckel, René Hänsel, Malgorzata Santel, Timm Denecke, Michael Dannemann, Mario Brosch, Jochen Hampe, Daniel Seehofer, Georg Damm, J. Gray Camp, Barbara Treutlein

Date Published: 3rd Jun 2021

Publication Type: Journal

Model-based identification of TNFalpha-induced IKKbeta-mediated and IkappaBalpha-mediated regulation of NFkappaB signal transduction as a tool to quantify the impact of drug-induced liver injury compounds.

Abstract (Expand)

Drug-induced liver injury (DILI) has become a major problem for patients and for clinicians, academics and the pharmaceutical industry. To date, existing hepatotoxicity test systems are only poorly … predictive and the underlying mechanisms are still unclear. One of the factors known to amplify hepatotoxicity is the tumor necrosis factor alpha (TNFalpha), especially due to its synergy with commonly used drugs such as diclofenac. However, the exact mechanism of how diclofenac in combination with TNFalpha induces liver injury remains elusive. Here, we combined time-resolved immunoblotting and live-cell imaging data of HepG2 cells and primary human hepatocytes (PHH) with dynamic pathway modeling using ordinary differential equations (ODEs) to describe the complex structure of TNFalpha-induced NFkappaB signal transduction and integrated the perturbations of the pathway caused by diclofenac. The resulting mathematical model was used to systematically identify parameters affected by diclofenac. These analyses showed that more than one regulatory module of TNFalpha-induced NFkappaB signal transduction is affected by diclofenac, suggesting that hepatotoxicity is the integrated consequence of multiple changes in hepatocytes and that multiple factors define toxicity thresholds. Applying our mathematical modeling approach to other DILI-causing compounds representing different putative DILI mechanism classes enabled us to quantify their impact on pathway activation, highlighting the potential of the dynamic pathway model as a quantitative tool for the analysis of DILI compounds.

Authors: A. Oppelt, D. Kaschek, S. Huppelschoten, R. Sison-Young, F. Zhang, M. Buck-Wiese, F. Herrmann, S. Malkusch, C. L. Kruger, M. Meub, B. Merkt, L. Zimmermann, A. Schofield, R. P. Jones, H. Malik, M. Schilling, M. Heilemann, B. van de Water, C. E. Goldring, B. K. Park, J. Timmer, U. Klingmuller

Date Published: 15th Jun 2018

Publication Type: Not specified

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