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Tellurium notebooks-An environment for reproducible dynamical modeling in systems biology.

Abstract (Expand)

The considerable difficulty encountered in reproducing the results of published dynamical models limits validation, exploration and reuse of this increasingly large biomedical research resource. To … address this problem, we have developed Tellurium Notebook, a software system for model authoring, simulation, and teaching that facilitates building reproducible dynamical models and reusing models by 1) providing a notebook environment which allows models, Python code, and narrative to be intermixed, 2) supporting the COMBINE archive format during model development for capturing model information in an exchangeable format and 3) enabling users to easily simulate and edit public COMBINE-compliant models from public repositories to facilitate studying model dynamics, variants and test cases. Tellurium Notebook, a Python-based Jupyter-like environment, is designed to seamlessly inter-operate with these community standards by automating conversion between COMBINE standards formulations and corresponding in-line, human-readable representations. Thus, Tellurium brings to systems biology the strategy used by other literate notebook systems such as Mathematica. These capabilities allow users to edit every aspect of the standards-compliant models and simulations, run the simulations in-line, and re-export to standard formats. We provide several use cases illustrating the advantages of our approach and how it allows development and reuse of models without requiring technical knowledge of standards. Adoption of Tellurium should accelerate model development, reproducibility and reuse.

Authors: J. K. Medley, K. Choi, M. Konig, L. Smith, S. Gu, J. Hellerstein, S. C. Sealfon, H. M. Sauro

Date Published: 16th Jun 2018

Publication Type: Not specified

Tellurium: An extensible python-based modeling environment for systems and synthetic biology.

Abstract (Expand)

Here we present Tellurium, a Python-based environment for model building, simulation, and analysis that facilitates reproducibility of models in systems and synthetic biology. Tellurium is a modular, … cross-platform, and open-source simulation environment composed of multiple libraries, plugins, and specialized modules and methods. Tellurium is a self-contained modeling platform which comes with a fully configured Python distribution. Two interfaces are provided, one based on the Spyder IDE which has an accessible user interface akin to MATLAB and a second based on the Jupyter Notebook, which is a format that contains live code, equations, visualizations, and narrative text. Tellurium uses libRoadRunner as the default SBML simulation engine which supports deterministic simulations, stochastic simulations, and steady-state analyses. Tellurium also includes Antimony, a human-readable model definition language which can be converted to and from SBML. Other standard Python scientific libraries such as NumPy, SciPy, and matplotlib are included by default. Additionally, we include several user-friendly plugins and advanced modules for a wide-variety of applications, ranging from complex algorithms for bifurcation analysis to multidimensional parameter scanning. By combining multiple libraries, plugins, and modules into a single package, Tellurium provides a unified but extensible solution for biological modeling and analysis for both novices and experts. AVAILABILITY: tellurium.analogmachine.org.

Authors: K. Choi, J. K. Medley, M. Konig, K. Stocking, L. Smith, S. Gu, H. M. Sauro

Date Published: 28th Jul 2018

Publication Type: Not specified

TGF-β1 and TGF-β2 abundance in liver diseases of mice and men

Abstract

Not specified

Authors: Anne Dropmann, Tatjana Dediulia, Katja Breitkopf-Heinlein, Hanna Korhonen, Michel Janicot, Susanne N. Weber, Maria Thomas, Albrecht Piiper, Esther Bertran, Isabel Fabregat, Kerstin Abshagen, Jochen Hess, Peter Angel, Cédric Coulouarn, Steven Dooley, Nadja M. Meindl-Beinker

Date Published: 12th Apr 2016

Publication Type: Not specified

TGF-beta in Hepatic Stellate Cell Activation and Liver Fibrogenesis-Updated 2019.

Abstract (Expand)

Liver fibrosis is an advanced liver disease condition, which could progress to cirrhosis and hepatocellular carcinoma. To date, there is no direct approved antifibrotic therapy, and current treatment … is mainly the removal of the causative factor. Transforming growth factor (TGF)-beta is a master profibrogenic cytokine and a promising target to treat fibrosis. However, TGF-beta has broad biological functions and its inhibition induces non-desirable side effects, which override therapeutic benefits. Therefore, understanding the pleiotropic effects of TGF-beta and its upstream and downstream regulatory mechanisms will help to design better TGF-beta based therapeutics. Here, we summarize recent discoveries and milestones on the TGF-beta signaling pathway related to liver fibrosis and hepatic stellate cell (HSC) activation, emphasizing research of the last five years. This comprises impact of TGF-beta on liver fibrogenesis related biological processes, such as senescence, metabolism, reactive oxygen species generation, epigenetics, circadian rhythm, epithelial mesenchymal transition, and endothelial-mesenchymal transition. We also describe the influence of the microenvironment on the response of HSC to TGF-beta. Finally, we discuss new approaches to target the TGF-beta pathway, name current clinical trials, and explain promises and drawbacks that deserve to be adequately addressed.

Authors: B. Dewidar, C. Meyer, S. Dooley, A. N. Meindl-Beinker

Date Published: 11th Nov 2019

Publication Type: Not specified

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

TGF-β2 silencing to target biliary-derived liver diseases

Abstract

Not specified

Authors: Anne Dropmann, Steven Dooley, Bedair Dewidar, Seddik Hammad, Tatjana Dediulia, Julia Werle, Vanessa Hartwig, Shahrouz Ghafoory, Stefan Woelfl, Hanna Korhonen, Michel Janicot, Katja Wosikowski, Timo Itzel, Andreas Teufel, Detlef Schuppan, Ana Stojanovic, Adelheid Cerwenka, Stefanie Nittka, Albrecht Piiper, Timo Gaiser, Naiara Beraza, Malgorzata Milkiewicz, Piotr Milkiewicz, John G Brain, David E J Jones, Thomas S Weiss, Ulrich M Zanger, Matthias Ebert, Nadja M Meindl-Beinker

Date Published: 28th Jan 2020

Publication Type: Not specified

TGFβR1 inhibition drives hepatocellular carcinoma proliferation through induction of toll‐like‐receptor signalling

Abstract (Expand)

Abstract Transforming growth factor (TGF)‐β and toll‐like receptors (TLRs) have been shown to independently modulate the proliferation of hepatocellular carcinoma (HCC). Since a direct cross‐talk between … (HCC). Since a direct cross‐talk between these two signalling pathways in HCC has not been clearly described before, we aimed here to explore the possibility of such interaction. A human HCC tissue array ( n  = 20 vs. four control samples), human HCC samples ( n  = 10) and steatohepatitis‐driven murine HCC samples (control, NASH and HCC; n  = 6/group) were immunostained for TGFβR1, pSMAD2, TRAF6, IRAK1 and PCNA. The results were confirmed by immunoblotting. Effects of constant activation of the SMAD pathway by constitutive expression of ALK5 or knockdown of mediators of TLR signalling, IRAK1 and MyD88, on HCC proliferation, were investigated in the HCC cell line (HUH‐7) after treatment with TGFβ1 cytokine or TGFβR1 kinase inhibitor (LY2157299) using PCNA and MTS assay. TGFβR1 expression is decreased in human and murine HCC and associated with downregulated pSMAD2, but increased IRAK1, TRAF6 and PCNA staining. TGFβR1 kinase inhibition abolished the cytostatic effects of TGFβ1 and led to the induction of IRAK1, pIRAK1 and elevated mRNA levels of TLR‐9. Overexpression of ALK5 and knockdown of MyD88 or IRAK1 augmented the cytostatic effects of TGFβ1 on HUH‐7. In another epithelial HCC cell line, that is, HepG2, TGFβR1 kinase inhibitor similarly elevated cellular proliferation. There is a balance between the canonical SMAD‐driven tumour‐suppressing arm and the non‐canonical tumour‐promoting arm of TGFβ signalling. Disruption of this balance, by inhibition of the canonical pathway, induces HCC proliferation through TLR signalling.

Authors: Fatma El Zahraa Ammar Mohamed, Bedair Dewidar, Tao Lin, Matthias P. Ebert, Steven Dooley, Nadja M. Meindl‐Beinker, Seddik Hammad

Date Published: 8th Feb 2024

Publication Type: Journal

The ascending pathophysiology of cholestatic liver disease

Abstract (Expand)

In this review we develop the argument that cholestatic liver diseases, particularly primary biliary cholangitis and primary sclerosing cholangitis (PSC), evolve over time with anatomically an ascending … course of the disease process. The first and early lesions are in "downstream" bile ducts. This eventually leads to cholestasis, and this causes bile salt (BS)-mediated toxic injury of the "upstream" liver parenchyma. BS are toxic in high concentration. These concentrations are present in the canalicular network, bile ducts, and gallbladder. Leakage of bile from this network and ducts could be an important driver of toxicity. The liver has a great capacity to adapt to cholestasis, and this may contribute to a variable symptom-poor interval that is often observed. Current trials with drugs that target BS toxicity are effective in only about 50%-60% of primary biliary cholangitis patients, with no effective therapy in PSC. This motivated us to develop and propose a new view on the pathophysiology of primary biliary cholangitis and PSC in the hope that these new drugs can be used more effectively. These views may lead to better stratification of these diseases and to recommendations on a more "tailored" use of the new therapeutic agents that are currently tested in clinical trials. Apical sodium-dependent BS transporter inhibitors that reduce intestinal BS absorption lower the BS load and are best used in cholestatic patients. The effectiveness of BS synthesis-suppressing drugs, such as farnesoid X receptor agonists, is greatest when optimal adaptation is not yet established. By the time cytochrome P450 7A1 expression is reduced these drugs may be less effective. Anti-inflammatory agents are probably most effective in early disease, while drugs that antagonize BS toxicity, such as ursodeoxycholic acid and nor-ursodeoxycholic acid, may be effective at all disease stages. Endoscopic stenting in PSC should be reserved for situations of intercurrent cholestasis and cholangitis, not for cholestasis in end-stage disease. These are arguments to consider a step-wise pathophysiology for these diseases, with therapy adjusted to disease stage. An obstacle in such an approach is that disease stage-defining biomarkers are still lacking. This review is meant to serve as a call to prioritize the development of biomarkers that help to obtain a better stratification of these diseases. (Hepatology 2017;65:722-738).

Authors: Peter L.M. Jansen, Ahmed Ghallab, Nachiket Vartak, Raymond Reif, Frank G. Schaap, Jochen Hampe, Jan G. Hengstler

Date Published: 1st Feb 2017

Publication Type: Not specified

The ascending pathophysiology of cholestatic liver disease.

Abstract (Expand)

In this review we develop the argument that cholestatic liver diseases, particularly primary biliary cholangitis and primary sclerosing cholangitis (PSC), evolve over time with anatomically an ascending … course of the disease process. The first and early lesions are in "downstream" bile ducts. This eventually leads to cholestasis, and this causes bile salt (BS)-mediated toxic injury of the "upstream" liver parenchyma. BS are toxic in high concentration. These concentrations are present in the canalicular network, bile ducts, and gallbladder. Leakage of bile from this network and ducts could be an important driver of toxicity. The liver has a great capacity to adapt to cholestasis, and this may contribute to a variable symptom-poor interval that is often observed. Current trials with drugs that target BS toxicity are effective in only about 50%-60% of primary biliary cholangitis patients, with no effective therapy in PSC. This motivated us to develop and propose a new view on the pathophysiology of primary biliary cholangitis and PSC in the hope that these new drugs can be used more effectively. These views may lead to better stratification of these diseases and to recommendations on a more "tailored" use of the new therapeutic agents that are currently tested in clinical trials. Apical sodium-dependent BS transporter inhibitors that reduce intestinal BS absorption lower the BS load and are best used in cholestatic patients. The effectiveness of BS synthesis-suppressing drugs, such as farnesoid X receptor agonists, is greatest when optimal adaptation is not yet established. By the time cytochrome P450 7A1 expression is reduced these drugs may be less effective. Anti-inflammatory agents are probably most effective in early disease, while drugs that antagonize BS toxicity, such as ursodeoxycholic acid and nor-ursodeoxycholic acid, may be effective at all disease stages. Endoscopic stenting in PSC should be reserved for situations of intercurrent cholestasis and cholangitis, not for cholestasis in end-stage disease. These are arguments to consider a step-wise pathophysiology for these diseases, with therapy adjusted to disease stage. An obstacle in such an approach is that disease stage-defining biomarkers are still lacking. This review is meant to serve as a call to prioritize the development of biomarkers that help to obtain a better stratification of these diseases. (Hepatology 2017;65:722-738).

Authors: P. L. Jansen, A. Ghallab, N. Vartak, R. Reif, F. G. Schaap, J. Hampe, J. G. Hengstler

Date Published: 17th Feb 2017

Publication Type: Not specified

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

The Diurnal Timing of Starvation Differently Impacts Murine Hepatic Gene Expression and Lipid Metabolism – A Systems Biology Analysis Using Self-Organizing Maps

Abstract

Not specified

Authors: Christiane Rennert, Sebastian Vlaic, Eugenia Marbach-Breitrück, Carlo Thiel, Susanne Sales, Andrej Shevchenko, Rolf Gebhardt, Madlen Matz-Soja

Date Published: 10th Sep 2018

Publication Type: Not specified

The first 10 years of the international coordination network for standards in systems and synthetic biology (COMBINE)

Abstract (Expand)

This paper presents a report on outcomes of the 10th Computational Modeling in Biology Network (COMBINE) meeting that was held in Heidelberg, Germany, in July of 2019. The annual event brings together … researchers, biocurators and software engineers to present recent results and discuss future work in the area of standards for systems and synthetic biology. The COMBINE initiative coordinates the development of various community standards and formats for computational models in the life sciences. Over the past 10 years, COMBINE has brought together standard communities that have further developed and harmonized their standards for better interoperability of models and data. COMBINE 2019 was co-located with a stakeholder workshop of the European EU-STANDS4PM initiative that aims at harmonized data and model standardization for in silico models in the field of personalized medicine, as well as with the FAIRDOM PALs meeting to discuss findable, accessible, interoperable and reusable (FAIR) data sharing. This report briefly describes the work discussed in invited and contributed talks as well as during breakout sessions. It also highlights recent advancements in data, model, and annotation standardization efforts. Finally, this report concludes with some challenges and opportunities that this community will face during the next 10 years.

Authors: Dagmar Waltemath, Martin Golebiewski, Michael L Blinov, Padraig Gleeson, Henning Hermjakob, Michael Hucka, Esther Thea Inau, Sarah M Keating, Matthias König, Olga Krebs, Rahuman S Malik-Sheriff, David Nickerson, Ernst Oberortner, Herbert M Sauro, Falk Schreiber, Lucian Smith, Melanie I Stefan, Ulrike Wittig, Chris J Myers

Date Published: 29th Jun 2020

Publication Type: Journal

The formation of estrogen-like tamoxifen metabolites and their influence on enzyme activity and gene expression of ADME genes.

Abstract (Expand)

Tamoxifen, a standard therapy for breast cancer, is metabolized to compounds with anti-estrogenic as well as estrogen-like action at the estrogen receptor. Little is known about the formation of … estrogen-like metabolites and their biological impact. Thus, we characterized the estrogen-like metabolites tamoxifen bisphenol and metabolite E for their metabolic pathway and their influence on cytochrome P450 activity and ADME gene expression. The formation of tamoxifen bisphenol and metabolite E was studied in human liver microsomes and Supersomes. Cellular metabolism and impact on CYP enzymes was analyzed in upcyte(R) hepatocytes. The influence of 5 microM of tamoxifen, anti-estrogenic and estrogen-like metabolites on CYP activity was measured by HPLC MS/MS and on ADME gene expression using RT-PCR analyses. Metabolite E was formed from tamoxifen by CYP2C19, 3A and 1A2 and from desmethyltamoxifen by CYP2D6, 1A2 and 3A. Tamoxifen bisphenol was mainly formed from (E)- and (Z)-metabolite E by CYP2B6 and CYP2C19, respectively. Regarding phase II metabolism, UGT2B7, 1A8 and 1A3 showed highest activity in glucuronidation of tamoxifen bisphenol and metabolite E. Anti-estrogenic metabolites (Z)-4-hydroxytamoxifen, (Z)-endoxifen and (Z)-norendoxifen inhibited the activity of CYP2C enzymes while tamoxifen bisphenol consistently induced CYPs similar to rifampicin and phenobarbital. On the transcript level, highest induction up to 5.6-fold was observed for CYP3A4 by tamoxifen, (Z)-4-hydroxytamoxifen, tamoxifen bisphenol and (E)-metabolite E. Estrogen-like tamoxifen metabolites are formed in CYP-dependent reactions and are further metabolized by glucuronidation. The induction of CYP activity by tamoxifen bisphenol and the inhibition of CYP2C enzymes by anti-estrogenic metabolites may lead to drug-drug-interactions.

Authors: J. Johanning, P. Kroner, M. Thomas, U. M. Zanger, A. Norenberg, M. Eichelbaum, M. Schwab, H. Brauch, W. Schroth, T. E. Murdter

Date Published: 28th Dec 2017

Publication Type: Not specified

The fruit fly Drosophila melanogaster as an innovative preclinical ADME model for solute carrier membrane transporters, with consequences for pharmacology and drug therapy.

Abstract (Expand)

Solute carrier membrane transporters (SLCs) control cell exposure to small-molecule drugs, thereby contributing to drug efficacy and failure and/or adverse effects. Moreover, SLCs are genetically linked … to various diseases. Hence, in-depth knowledge of SLC function is fundamental for a better understanding of disease pathophysiology and the drug development process. Given that the model organism Drosophila melanogaster (fruit fly) expresses SLCs, such as for the excretion of endogenous and toxic compounds by the hindgut and Malpighian tubules, equivalent to human intestine and kidney, this system appears to be a promising preclinical model to use to study human SLCs. Here, we systematically compare current knowledge of SLCs in Drosophila and humans and describe the Drosophila model as an innovative tool for drug development.

Authors: Y. Wang, B. Moussian, E. Schaeffeler, M. Schwab, A. T. Nies

Date Published: 12th Jun 2018

Publication Type: Not specified

The genetics of alcohol dependence and alcohol-related liver disease.

Abstract (Expand)

The susceptibility to developing alcohol dependence and significant alcohol-related liver injury is determined by a number of constitutional, environmental and genetic factors, although the nature and … level of interplay between them remains unclear. The familiality and heritability of alcohol dependence is well-documented but, to date, no strong candidate genes conferring increased risk have emerged, although variants in alcohol dehydrogenase and acetaldehyde dehydrogenase have been shown to confer protection, predominantly in individuals of East Asian ancestry. Population contamination with confounders such as drug co-dependence and psychiatric and physical co-morbidity may explain the essentially negative genome-wide association studies in this disorder. The familiality and hereditability of alcohol-related cirrhosis is not as well-documented but three strong candidate genes PNPLA3, TM6SF2 and MBOAT7, have been identified. The mechanisms by which variants in these genes confer risk and the nature of the functional interplay between them remains to be determined but, when elucidated, will undoubtedly increase our understanding of the pathophysiology of this disease. The way in which this genetic information could potentially inform patient management has yet to be determined and tested.

Authors: F. Stickel, C. Moreno, J. Hampe, M. Y. Morgan

Date Published: 27th Aug 2016

Publication Type: Not specified

The Human Physiome: how standards, software and innovative service infrastructures are providing the building blocks to make it achievable

Abstract (Expand)

Reconstructing and understanding the Human Physiome virtually is a complex mathematical problem, and a highly demanding computational challenge. Mathematical models spanning from the molecular level … through to whole populations of individuals must be integrated, then personalized. This requires interoperability with multiple disparate and geographically separated data sources, and myriad computational software tools. Extracting and producing knowledge from such sources, even when the databases and software are readily available, is a challenging task. Despite the difficulties, researchers must frequently perform these tasks so that available knowledge can be continually integrated into the common framework required to realize the Human Physiome. Software and infrastructures that support the communities that generate these, together with their underlying standards to format, describe and interlink the corresponding data and computer models, are pivotal to the Human Physiome being realized. They provide the foundations for integrating, exchanging and re-using data and models efficiently, and correctly, while also supporting the dissemination of growing knowledge in these forms. In this paper, we explore the standards, software tooling, repositories and infrastructures that support this work, and detail what makes them vital to realizing the Human Physiome.

Authors: D. Nickerson, K. Atalag, B. de Bono, J. Geiger, C. Goble, S. Hollmann, J. Lonien, W. Muller, B. Regierer, N. J. Stanford, M. Golebiewski, P. Hunter

Date Published: 7th Apr 2016

Publication Type: Not specified

The importance of drug transporter characterization to precision medicine.

Abstract

Not specified

Authors: P. Fisel, A. T. Nies, E. Schaeffeler, M. Schwab

Date Published: 1st Feb 2017

Publication Type: Not specified

The importance of membrane microdomains for bile salt-dependent biliary lipid secretion.

Abstract (Expand)

Alternative models explaining the biliary lipid secretion at the canalicular membrane of hepatocytes exist: successive lipid extraction by preformed bile salt micelles, or budding of membrane fragments … with formation of mixed micelles. To test the feasibility of the latter mechanism, we developed a mathematical model that describes the formation of lipid microdomains in the canalicular membrane. Bile salt monomers intercalate into the external hemileaflet of the canalicular membrane, to form a rim to liquid disordered domain patches that then pinch off to form nanometer-scale mixed micelles. Model simulations perfectly recapitulate the measured dependence of bile salt-dependent biliary lipid extraction rates upon modulation of the membrane cholesterol (lack or overexpression of the cholesterol transporter Abcg5-Abcg8) and phosphatidylcholine (lack of Mdr2, also known as Abcb4) content. The model reveals a strong dependence of the biliary secretion rate on the protein density of the membrane. Taken together, the proposed model is consistent with crucial experimental findings in the field and provides a consistent explanation of the central molecular processes involved in bile formation.

Authors: J. Eckstein, H. G. Holzhutter, N. Berndt

Date Published: 1st Mar 2018

Publication Type: Not specified

The Interplay of TGF-β1 and Cholesterol Orchestrating Hepatocyte Cell Fate, EMT, and Signals for HSC Activation

Abstract

Not specified

Authors: Sai Wang, Frederik Link, Mei Han, Roohi Chaudhary, Anastasia Asimakopoulos, Roman Liebe, Ye Yao, Seddik Hammad, Anne Dropmann, Marinela Krizanac, Claudia Rubie, Laura Kim Feiner, Matthias Glanemann, Matthias P.A. Ebert, Ralf Weiskirchen, Yoav I. Henis, Marcelo Ehrlich, Steven Dooley

Date Published: 2024

Publication Type: Journal

The level of caveolin-1 expression determines response to TGF-β as a tumour suppressor in hepatocellular carcinoma cells

Abstract

Not specified

Authors: Joaquim Moreno-Càceres, Daniel Caballero-Díaz, Zeribe Chike Nwosu, Christoph Meyer, Judit López-Luque, Andrea Malfettone, Raquel Lastra, Teresa Serrano, Emilio Ramos, Steven Dooley, Isabel Fabregat

Date Published: 12th Oct 2017

Publication Type: Not specified

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

The PNPLA3 I148M variant promotes lipid-induced hepatocyte secretion of CXC chemokines establishing a tumorigenic milieu.

Abstract (Expand)

The I148M variant of the Patatin-like phospholipase domain-containing 3 (PNPLA3) protein is associated with an increased risk for liver inflammation and hepatocellular carcinoma (HCC), but the underlying … mechanism is unknown. We hypothesized that enhanced CXC chemokine secretion mediates hepatic inflammation that accelerates development of HCC. Expandable primary human (upcyte(R)) hepatocytes and human PLC/PRF/5 hepatoma cells were lentivirally transduced with both PNPLA3 I148M variants and stimulated with lipids. Cytokine levels in culture supernatant and patient sera (n = 80) were analyzed by ELISA. Supernatants were assessed in transmigration experiments, tube formation, and proliferation assays. In vitro, lipid stimulation of transduced hepatocytes dose-dependently induced the production of interleukin-8 and CXCL1 in hepatocytes carrying the PNPLA3 148M variant. In line, sera from PNPLA3 148M-positive patients with alcoholic liver cirrhosis contained higher levels of interleukin-8 and CXCL1 than patients with wild-type PNPLA3. Supernatants from lipid-stimulated hepatocytes with the PNPLA3 148M variant induced enhanced migration of white blood cells, angiogenesis, and cell proliferation in comparison with supernatants from wild-type hepatocytes via CXC receptors 1 and 2. Increased production of interleukin-8 and CXCL1 by hepatocytes carrying the PNPLA3 148M variant contributes to a pro-inflammatory and tumorigenic milieu in patients with alcoholic liver disease. KEY MESSAGES: The PNPLA3 148M variant is associated with cirrhosis and hepatocellular carcinoma. Lipid stimulation of hepatocytes with this variant induces IL-8 and CXCL1. Supernatants from hepatocytes with this variant promote migration and angiogenesis. Sera from patients with this variant contained enhanced levels of IL-8 and CXCL1. The PNPLA3 148M variant contributes to a tumorigenic milieu via IL-8 and CXCL1.

Authors: H. D. Nischalke, P. Lutz, E. Bartok, B. Kramer, B. Langhans, R. Frizler, T. Berg, J. Hampe, S. Buch, C. Datz, F. Stickel, G. Hartmann, C. P. Strassburg, J. Nattermann, U. Spengler

Date Published: 23rd Oct 2019

Publication Type: Journal

The predictive value of future liver remnant function after liver resection for HCC in noncirrhotic and cirrhotic patients.

Abstract (Expand)

BACKGROUND: Surgical procedures in patients with underlying liver disease are still burdened by a high rate of postoperative morbidity, especially posthepatectomy liver failure (PHLF), ranging from 1.2 … to 33.8%. The aim of this study was to investigate the prognostic value of volume/function analysis for the prediction of hepatectomy-related morbidity in patients with hepatocellular carcinoma. METHODS: Clinicopathological data were analysed in 261 patients who underwent liver resection for HCC between 2001 and 2014. Future liver remnant volume (FLRV) and future liver remnant function (FLRF) based on LiMAx test were obtained retrospectively. A subgroup analysis for high-risk patients with impaired liver function was conducted. Univariate and multivariate regression analysis was performed to identify risk factors for major complications, defined by Dindo >/= IIIb and PHLF grade >/= B. RESULTS: In the total cohort, FLRF was independently associated with major complications. FLRV, resected liver volume, and FLRF were independent risk factors for PHLF. In a subgroup analysis of high-risk patients, FLRF was identified as the only independent risk factor for major complications and PHLF development. DISCUSSION: These results suggest the superior value of FLRF to FLRV in predicting postoperative complications as well as PHLF in patients with chronic liver disease.

Authors: E. Bluthner, M. Jara, R. Shrestha, W. Faber, J. Pratschke, M. Stockmann, M. Malinowski

Date Published: 9th Feb 2019

Publication Type: Not specified

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

The relative importance of kinetic mechanisms and variable enzyme abundances for the regulation of hepatic glucose metabolism--insights from mathematical modeling.

Abstract (Expand)

BACKGROUND: Adaptation of the cellular metabolism to varying external conditions is brought about by regulated changes in the activity of enzymes and transporters. Hormone-dependent reversible enzyme … phosphorylation and concentration changes of reactants and allosteric effectors are the major types of rapid kinetic enzyme regulation, whereas on longer time scales changes in protein abundance may also become operative. Here, we used a comprehensive mathematical model of the hepatic glucose metabolism of rat hepatocytes to decipher the relative importance of different regulatory modes and their mutual interdependencies in the hepatic control of plasma glucose homeostasis. RESULTS: Model simulations reveal significant differences in the capability of liver metabolism to counteract variations of plasma glucose in different physiological settings (starvation, ad libitum nutrient supply, diabetes). Changes in enzyme abundances adjust the metabolic output to the anticipated physiological demand but may turn into a regulatory disadvantage if sudden unexpected changes of the external conditions occur. Allosteric and hormonal control of enzyme activities allow the liver to assume a broad range of metabolic states and may even fully reverse flux changes resulting from changes of enzyme abundances alone. Metabolic control analysis reveals that control of the hepatic glucose metabolism is mainly exerted by enzymes alone, which are differently controlled by alterations in enzyme abundance, reversible phosphorylation, and allosteric effects. CONCLUSION: In hepatic glucose metabolism, regulation of enzyme activities by changes of reactants, allosteric effects, and reversible phosphorylation is equally important as changes in protein abundance of key regulatory enzymes.

Authors: S. Bulik, H. G. Holzhutter, N. Berndt

Date Published: 2nd Mar 2016

Publication Type: Not specified

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

The Systems Biology Markup Language (SBML): Language Specification for Level 3 Version 2 Core Release 2.

Abstract (Expand)

Computational models can help researchers to interpret data, understand biological functions, and make quantitative predictions. The Systems Biology Markup Language (SBML) is a file format for representing … computational models in a declarative form that different software systems can exchange. SBML is oriented towards describing biological processes of the sort common in research on a number of topics, including metabolic pathways, cell signaling pathways, and many others. By supporting SBML as an input/output format, different tools can all operate on an identical representation of a model, removing opportunities for translation errors and assuring a common starting point for analyses and simulations. This document provides the specification for Release 2 of Version 2 of SBML Level 3 Core. The specification defines the data structures prescribed by SBML as well as their encoding in XML, the eXtensible Markup Language. Release 2 corrects some errors and clarifies some ambiguities discovered in Release 1. This specification also defines validation rules that determine the validity of an SBML document, and provides many examples of models in SBML form. Other materials and software are available from the SBML project website at http://sbml.org/.

Authors: M. Hucka, F. T. Bergmann, C. Chaouiya, A. Drager, S. Hoops, S. M. Keating, M. Konig, N. L. Novere, C. J. Myers, B. G. Olivier, S. Sahle, J. C. Schaff, R. Sheriff, L. P. Smith, D. Waltemath, D. J. Wilkinson, F. Zhang

Date Published: 20th Jun 2019

Publication Type: Not specified

Therapeutic modulation of the liver immune microenvironment

Abstract

Not specified

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

Date Published: 2023

Publication Type: Journal

Three-dimensional spatially resolved geometrical and functional models of human liver tissue reveal new aspects of NAFLD progression.

Abstract (Expand)

Early disease diagnosis is key to the effective treatment of diseases. Histopathological analysis of human biopsies is the gold standard to diagnose tissue alterations. However, this approach has low … resolution and overlooks 3D (three-dimensional) structural changes resulting from functional alterations. Here, we applied multiphoton imaging, 3D digital reconstructions and computational simulations to generate spatially resolved geometrical and functional models of human liver tissue at different stages of non-alcoholic fatty liver disease (NAFLD). We identified a set of morphometric cellular and tissue parameters correlated with disease progression, and discover profound topological defects in the 3D bile canalicular (BC) network. Personalized biliary fluid dynamic simulations predicted an increased pericentral biliary pressure and micro-cholestasis, consistent with elevated cholestatic biomarkers in patients' sera. Our spatially resolved models of human liver tissue can contribute to high-definition medicine by identifying quantitative multiparametric cellular and tissue signatures to define disease progression and provide new insights into NAFLD pathophysiology.

Authors: F. Segovia-Miranda, H. Morales-Navarrete, M. Kucken, V. Moser, S. Seifert, U. Repnik, F. Rost, M. Brosch, A. Hendricks, S. Hinz, C. Rocken, D. Lutjohann, Y. Kalaidzidis, C. Schafmayer, L. Brusch, J. Hampe, M. Zerial

Date Published: 2nd Dec 2019

Publication Type: Not specified

Tick-tock hedgehog-mutual crosstalk with liver circadian clock promotes liver steatosis.

Abstract (Expand)

BACKGROUND & AIMS: The mammalian circadian clock controls various aspects of liver metabolism and integrates nutritional signals. Recently, we described Hedgehog (Hh) signaling as a novel regulator … of liver lipid metabolism. Herein, we investigated crosstalk between hepatic Hh signaling and circadian rhythm. METHODS: Diurnal rhythms of Hh signaling were investigated in liver and hepatocytes from mice with ablation of Smoothened (SAC-KO) and crossbreeds with PER2::LUC reporter mice. By using genome-wide screening, qPCR, immunostaining, ELISA and RNAi experiments in vitro we identified relevant transcriptional regulatory steps. Shotgun lipidomics and metabolic cages were used for analysis of metabolic alterations and behavior. RESULTS: Hh signaling showed diurnal oscillations in liver and hepatocytes in vitro. Correspondingly, the level of Indian Hh, oscillated in serum. Depletion of the clock gene Bmal1 in hepatocytes resulted in significant alterations in the expression of Hh genes. Conversely, SAC-KO mice showed altered expression of clock genes, confirmed by RNAi against Gli1 and Gli3. Genome-wide screening revealed that SAC-KO hepatocytes showed time-dependent alterations in various genes, particularly those associated with lipid metabolism. The clock/hedgehog module further plays a role in rhythmicity of steatosis, and in the response of the liver to a high-fat diet or to differently timed starvation. CONCLUSIONS: For the first time, Hh signaling in hepatocytes was found to be time-of-day dependent and to feed back on the circadian clock. Our findings suggest an integrative role of Hh signaling, mediated mainly by GLI factors, in maintaining homeostasis of hepatic lipid metabolism by balancing the circadian clock. LAY SUMMARY: The results of our investigation show for the first time that the Hh signaling in hepatocytes is time-of-day dependent, leading to differences not only in transcript levels but also in the amount of Hh ligands in peripheral blood. Conversely, Hh signaling is able to feed back to the circadian clock.

Authors: E. Marbach-Breitruck, M. Matz-Soja, U. Abraham, W. Schmidt-Heck, S. Sales, C. Rennert, M. Kern, S. Aleithe, L. Spormann, C. Thiel, R. Gerlini, K. Arnold, N. Kloting, R. Guthke, D. Rozman, R. Teperino, A. Shevchenko, A. Kramer, R. Gebhardt

Date Published: 4th Feb 2019

Publication Type: Not specified

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

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

Tomoelastography Distinguishes Noninvasively between Benign and Malignant Liver Lesions.

Abstract (Expand)

Patients with increased liver stiffness have a higher risk of developing cancer, however, the role of fluid-solid tissue interactions and their contribution to liver tumor malignancy remains elusive. … Tomoelastography is a novel imaging method for mapping quantitatively the solid-fluid tissue properties of soft tissues in vivo. It provides high resolution and thus has clear clinical applications. In this work we used tomoelastography in 77 participants, with a total of 141 focal liver lesions of different etiologies, to investigate the contributions of tissue stiffness and fluidity to the malignancy of liver tumors. Shear-wave speed (c) as surrogate for tissue stiffness and phase-angle (phi) of the complex shear modulus reflecting tissue fluidity were abnormally high in malignant tumors and allowed them to be distinguished from nontumorous liver tissue with high accuracy [c: AUC = 0.88 with 95% confidence interval (CI) = 0.83-0.94; phi: AUC = 0.95, 95% CI = 0.92-0.98]. Benign focal nodular hyperplasia and hepatocellular adenoma could be distinguished from malignant lesions on the basis of tumor stiffness (AUC = 0.85, 95% CI = 0.72-0.98; sensitivity = 94%, 95% CI = 89-100; and specificity = 85%, 95% CI = 62-100), tumor fluidity (AUC = 0.86, 95% CI = 0.77-0.96; sensitivity = 83%, 95% CI = 72-93; and specificity = 92%, 95% CI = 77-100) and liver stiffness (AUC = 0.84, 95% CI = 0.74-0.94; sensitivity = 72%, 95% CI = 59-83; and specificity = 88%, 95% CI = 69-100), but not on the basis of liver fluidity. Together, hepatic malignancies are characterized by stiff, yet fluid tissue properties, whereas surrounding nontumorous tissue is dominated by solid properties. Tomoelastography can inform noninvasively on the malignancy of suspicious liver lesions by differentiating between benign and malignant lesions with high sensitivity based on stiffness and with high specificity based on fluidity. SIGNIFICANCE: Solid-fluid tissue properties measured by tomoelastography can distinguish malignant from benign masses with high accuracy and provide quantitative noninvasive imaging biomarkers for liver tumors.

Authors: M. Shahryari, H. Tzschatzsch, J. Guo, S. R. Marticorena Garcia, G. Boning, U. Fehrenbach, L. Stencel, P. Asbach, B. Hamm, J. A. Kas, J. Braun, T. Denecke, I. Sack

Date Published: 15th Nov 2019

Publication Type: Not specified

Tomoelastography for Longitudinal Monitoring of Viscoelasticity Changes in the Liver and in Renal Allografts after Direct-Acting Antiviral Treatment in 15 Kidney Transplant Recipients with Chronic HCV Infection.

Abstract (Expand)

Besides the liver, hepatitis C virus (HCV) infection also affects kidney allografts. The aim of this study was to longitudinally evaluate viscoelasticity changes in the liver and in kidney allografts … in kidney transplant recipients (KTRs) with HCV infection after treatment with direct-acting antiviral agents (DAAs). Fifteen KTRs with HCV infection were treated with DAAs (daclatasvir and sofosbuvir) for 3 months and monitored at baseline, end of treatment (EOT), and 3 (FU1) and 12 (FU2) months after EOT. Shear-wave speed (SWS) and loss angle of the complex shear modulus (phi), reflecting stiffness and fluidity, respectively, were reconstructed from multifrequency magnetic resonance elastography data with tomoelastography post-processing. After virus elimination by DAAs, hepatic stiffness and fluidity decreased, while kidney allograft stiffness and fluidity increased compared with baseline (hepatic stiffness change at FU1: -0.14 m/s, p < 0.01, and at FU2: -0.11 m/s, p < 0.05; fluidity at FU1: -0.05 rad, p = 0.04 and unchanged at FU2: p = 0.20; kidney allograft stiffness change at FU1: +0.27 m/s, p = 0.01, and at FU2: +0.30 m/s, p < 0.01; fluidity at FU1 and FU2: +0.06 rad, p = 0.02). These results suggest the restoration of mechanically sensitive structures and functions in both organs. Tomoelastography can be used to monitor the therapeutic results of HCV treatment non-invasively on the basis of hepatic and renal viscoelastic parameters.

Authors: S. R. Marticorena Garcia, C. E. Althoff, M. Durr, F. Halleck, K. Budde, U. Grittner, C. Burkhardt, K. Johrens, J. Braun, T. Fischer, B. Hamm, I. Sack, J. Guo

Date Published: 1st Feb 2021

Publication Type: Journal

Tomoelastography for Measurement of Tumor Volume Related to Tissue Stiffness in Pancreatic Ductal Adenocarcinomas.

Abstract (Expand)

OBJECTIVES: Estimations of tumor volume and boundary in pancreatic ductal adenocarcinoma (PDAC) are crucial for surgery planning. The aim of the study is to evaluate tomoelastography for detection of … PDAC and quantification of PDAC volume based on tissue stiffness. MATERIALS AND METHODS: From March 2018 to December 2019, a total of 102 participants (30 healthy participants and 72 patients with histologically proven PDAC) were prospectively enrolled in a multicenter study. Multifrequency magnetic resonance elastography was combined with tomoelastography postprocessing to generate maps of shear wave speed (SWS) depicting highly resolved anatomical details of tissue stiffness. Subregional analysis of pancreatic head, body, and tail and reproducibility tests were performed in healthy participants, whereas tumorous (PDAC-T) and nontumorous (PDAC-NT) pancreatic tissue analysis was conducted in patients. In all patients, tumor volumes measured by computed tomography (CT) were compared with SWS-derived volumes. In addition, in 32 patients, tumor sizes were evaluated by macroscopy after resection. RESULTS: Tumor volumes were quantified in 99% and 87% of all cases with tomoelastography and CT, respectively. Pancreatic SWS was highly reproducible (repeatability coefficient = 0.12) and did not vary regionally or with patient age, sex, or body mass index (all P > 0.08). Shear wave speed was higher in PDAC-T (2.08 +/- 0.38 m/s) than in healthy (1.25 +/- 0.09 m/s; P < 0.001) and PDAC-NT (1.28 +/- 0.14 m/s; P < 0.001) participants. A threshold of 1.47 m/s separated PDAC-T from healthy volunteers (area under the curve = 1.0, sensitivity = 100%, specificity = 100%), while 1.49 m/s separated PDAC-T from PDAC-NT with high accuracy (area under the curve = 0.99, sensitivity = 90%, specificity = 100%). Tomoelastography-derived tumor volume correlated with CT volume (r = 0.91, P < 0.001) and ex vivo tumor volume (r = 0.66, P < 0.001). CONCLUSIONS: Tomoelastography provides a quantitative imaging marker for tissue stiffness depicting PDAC boundaries and separates PDAC from unaffected pancreatic tissue.

Authors: S. R. Marticorena Garcia, L. Zhu, E. Gultekin, R. Schmuck, C. Burkhardt, M. Bahra, D. Geisel, M. Shahryari, J. Braun, B. Hamm, Z. Y. Jin, I. Sack, J. Guo

Date Published: 17th Aug 2020

Publication Type: Journal

Tomoelastography for non-invasive detection and treatment monitoring in acute appendicitis.

Abstract (Expand)

Acute appendicitis is the most common cause of the acute abdomen syndrome and can be treated either surgically or conservatively with antibiotics. This case demonstrates the first time use of mechanics … based MRI by tomoelastography with generation of quantitative maps of tissue stiffness (shear wave speed in m/s) and tissue fluidity (shear modulus loss angle, in rad) in a case of uncomplicated acute appendicitis with antibiotic treatment at (i) baseline, (ii) the end of treatment (EOT) and (iii) the 10 day follow-up after EOT. Baseline maps of stiffness and fluidity revealed to the naked eye the extent of intestinal inflammation by markedly increased values of stiffness and fluidity (2.56+/-0.12 m/s, 1.37+/-0.24 rad) compared with normal values, indicating the immediate response to antibiotic treatment at EOT (1.47+/-0.28 m/s, 0.80+/-0.11 rad) and persistent normalisation at follow-up (1.54+/-0.22 m/s, 0.92+/-0.22 rad). Tomoelastography is a non-invasive, quantitative imaging method for mechanics based characterisation and follow-up of acute appendicitis.

Authors: S. R. Marticorena Garcia, B. Hamm, I. Sack

Date Published: 26th Aug 2019

Publication Type: Not specified

Tomoelastography for the Evaluation of Pediatric Nonalcoholic Fatty Liver Disease

Abstract (Expand)

OBJECTIVES: Today, nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adults alike. Yet, the noninvasive evaluation of disease severity remains a diagnostic …c challenge. In this study, we apply multifrequency magnetic resonance elastography (mMRE) for the quantification of liver steatosis and fibrosis in adolescents with NAFLD. METHODS: Fifty adolescents (age range, 10-17 years; mean BMI, 33.9 kg/m; range, 21.4-42.1 kg/m) with biopsy-proven NAFLD were included in this prospective study. Multifrequency magnetic resonance elastography was performed using external multifrequency vibrations of 30 to 60 Hz and tomoelastography postprocessing, resulting in penetration rate (a) and shear wave speed (c). Hepatic fat fraction was determined using Dixon method. The diagnostic accuracy of mMRE in grading liver steatosis and staging liver fibrosis was assessed by receiver operating characteristic curve analysis. RESULTS: Multifrequency magnetic resonance elastography parameters c and a were independently sensitive to fibrosis and steatosis, respectively, providing area under the receiver operating characteristic values of 0.79 (95% confidence interval [CI], 0.66-0.92), 0.91 (95% CI, 0.83-0.99), and 0.90 (95% CI, 0.80-0.99) for the detection of any (≥F1), moderate (≥F2), and advanced (≥F3) fibrosis, and 0.87 (95% CI, 0.76-0.97) and 0.87 (95% CI, 0.77-0.96) for the detection of moderate (≥S2) and severe (S3) steatosis. CONCLUSIONS: One mMRE measurement provides 2 independent parameters with very good diagnostic accuracy in detecting moderate and advanced fibrosis as well as moderate and severe steatosis in pediatric NAFLD.

Authors: Christian A. Hudert, Heiko Tzschätzsch, Birgit Rudolph, Hendrik Bläker, Christoph Loddenkemper, Hans-Peter Müller, Stephan Henning, Philip Bufler, Bernd Hamm, Jürgen Braun, Hermann-Georg Holzhütter, Susanna Wiegand, Ingolf Sack, Jing Guo

Date Published: 1st Apr 2019

Publication Type: Not specified

Tomoelastography of the abdomen: Tissue mechanical properties of the liver, spleen, kidney, and pancreas from single MR elastography scans at different hydration states.

Abstract (Expand)

PURPOSE: To develop a compact magnetic resonance elastography (MRE) protocol for abdomen and to investigate the effect of water uptake on tissue stiffness in the liver, spleen, kidney, and pancreas. … METHODS: Nine asymptomatic volunteers were investigated by MRE before and after 1 liter water uptake. Shear-wave excitation at four frequencies was transferred to the abdomen from anterior and posterior directions using pressurized air drivers. Tomographic representations of shear-wave speed were produced by analysis of multifrequency wave numbers in axial and coronal images acquired within four breath-holds or under free breathing, respectively. RESULTS: Pre and post water, stiffness of the spleen (pre/post: 2.20 +/- 0.10/2.06 +/- 0.18 m/s) and kidney (pre/post: 1.93 +/- 0.22/1.97 +/- 0.23 m/s) was higher than in the liver (pre/post: 1.36 +/- 0.10/1.38 +/- 0.13 m/s) and pancreas (pre/post: 1.20 +/- 0.12/1.20 +/- 0.08 m/s), all P < 0.01. Accounting for four drive frequencies, water drinking only changed the splenic stiffness (-6%, P = 0.03), whereas in the frequency range from 50 to 60 Hz the effect became significant also in the pancreas (-6%, P = 0.04) and liver (+3%, P = 0.03). Elastograms of the kidney in coronal view clearly depicted higher stiffness in cortex than in medulla. CONCLUSION: Tomoelastography reveals sensitivity of tissue mechanical properties to the hydration state of multiple abdominal organs within one scan and in unprecedented resolution of anatomical details. Magn Reson Med 78:976-983, 2017. (c) 2016 International Society for Magnetic Resonance in Medicine.

Authors: F. Dittmann, H. Tzschatzsch, S. Hirsch, E. Barnhill, J. Braun, I. Sack, J. Guo

Date Published: 3rd Oct 2016

Publication Type: Not specified

Tomoelastography of the native kidney: Regional variation and physiological effects on in vivo renal stiffness.

Abstract (Expand)

PURPOSE: To measure normal renal stiffness in adults, taking into account regional variation, hydration, and urinary status. METHODS: Thirty-six healthy volunteers were examined by tomoelastography … based on MR elastography at four frequencies, from 40 to 70 Hz and multifrequency shear wave speed recovery. Regional wave speeds were derived for the medulla, cortex (inner cortex and outer cortex), and renal pelvis, and examined for age-related effects. Subgroups were repeatedly examined for reproducibility, amount of prior water drinking, and urinary status. Variations in renal perfusion were simulated ex vivo using a porcine kidney subjected to venous water inflow at different pressures. RESULTS: Shear wave speed (stiffness) of renal parenchyma was 2.46 +/- 0.12 m/s (inner cortex: 2.91 +/- 0.17 m/s; outer cortex: 2.52 +/- 0.11 m/s; medulla: 2.15 +/- 0.08 m/s) without side differences and a tendency toward softening with age (P = 0.028). Corresponding intraclass correlation for reproducibility coefficients were 0.78 (inner cortex: 0.80; outer cortex: 0.81; medulla: 0.80). Water drinking resulted in slightly higher values in inner cortex and lower values in medulla (both P = 0.039), which was consistent with the results in perfused specimens. A full bladder led to higher renal pelvis stiffness (P = 0.004), whereas renal parenchyma remained uninfluenced. Stiffness of the porcine renal cortex increased with venous inflow pressure, whereas medulla stiffness decreased. CONCLUSIONS: Tomoelastography provides full field of view maps of renal stiffness with highly detailed resolution and sensitivity to physiological effects related to age and fluid-solid tissue interactions. These basic data could be used to compare pathological conditions in the future. Magn Reson Med, 2017. (c) 2017 International Society for Magnetic Resonance in Medicine.

Authors: S. R. Marticorena Garcia, M. Grossmann, S. T. Lang, H. Tzschatzsch, F. Dittmann, B. Hamm, J. Braun, J. Guo, I. Sack

Date Published: 30th Aug 2017

Publication Type: Not specified

Tomoelastography of the prostate using multifrequency MR elastography and externally placed pressurized-air drivers.

Abstract (Expand)

PURPOSE: To demonstrate the feasibility of in vivo multifrequency magnetic resonance elastography (MRE) of the prostate using externally placed drivers. METHODS: Three pressurized-air drivers were used … to excite shear waves within the prostate at vibration frequencies of 60, 70, and 80 Hz. Full 3D wave fields were acquired by multislice spin-echo echo-planar imaging in conjunction with tomoelastography wave speed recovery for generating full field-of-view stiffness maps. Twelve healthy volunteers were repeatedly scanned to analyze test-retest reproducibility. Five patients with suspected prostate cancer were investigated to demonstrate the clinical feasibility of the method. RESULTS: In healthy volunteers, the shear wave speed of the entire prostate was 2.24 +/- 0.20 m/s with a repeatability coefficient of 0.14 m/s and 88% intraclass correlation coefficient. No significant difference between the peripheral zone (2.27 +/- 0.20 m/s) and the central gland (2.22 +/- 0.23 m/s) was observed. In patients, wave-speed maps displayed stiff regions consistent with the localization of suspicious masses detected by other imaging markers. CONCLUSIONS: The proposed method provides reproducible quantitative maps of tissue stiffness throughout the pelvic region and can easily be integrated into clinical imaging protocols. Clinical stiffness maps display many details of potential interest for cancer diagnosis. Magn Reson Med 79:1325-1333, 2018. (c) 2017 International Society for Magnetic Resonance in Medicine.

Authors: F. Dittmann, R. Reiter, J. Guo, M. Haas, P. Asbach, T. Fischer, J. Braun, I. Sack

Date Published: 6th Jun 2017

Publication Type: Not specified

Tomoelastography Paired With T2* Magnetic Resonance Imaging Detects Lupus Nephritis With Normal Renal Function.

Abstract (Expand)

OBJECTIVES: The aim of this study was to test multiparametric magnetic resonance imaging including blood oxygen level-dependent (BOLD) imaging by T2* mapping, magnetic resonance elastography (MRE) by … tomoelastography, and diffusion-weighted imaging (DWI) for detecting nephropathy in patients with lupus nephritis (LN). METHODS: Forty-one subjects (25 patients with LN and 16 age- and sex-matched healthy volunteers; LN: mean age, 47.3 +/- 14.8 years; 22 female subjects; volunteers: mean age, 43.9 +/- 11.6 years; 13 female subjects) were prospectively enrolled. The LN group was further divided into subgroups with normal (LN-nRF, GFR > 90 mL/min per 1.73 m) and compromised renal function (LN-cRF, GFR < 90 mL/min per 1.73 m). All subjects were examined by multifrequency MRE, BOLD imaging, and DWI, yielding shear wave speed (SWS; in meter per second), T2* relaxation times (in millisecond), and apparent diffusion coefficient (ADC; in millimeter square per second), respectively. Renal subregional analysis was performed for the medulla (ME), inner cortex (CoI), and outer cortex (CoO). Imaging markers were correlated to clinical parameters such as GFR and protein-to-urine creatinine ratio. Cutoffs and area under the receiver operating curve (AUROC) were computed to test diagnostic performances. RESULTS: Compared with CoI and CoO, LN-nRF predominantly affects ME tissue (SWS: -7%, P < 0.01; T2*: +9%, P < 0.05; ADC: -5%, P = 0.27). Detection of LN-nRF was better with MRE compared with BOLD imaging and DWI (AUROC = 0.81, 0.76, not significant), whereas pairing MRE with T2* further increased diagnostic power (AUROC = 0.91). Disease progression was associated with reduction of SWS also in CoI (LN-nRF, 3.04 +/- 0.38 m/s; LN-cRF, 2.60 +/- 0.26 m/s; p = 0.013), allowing distinction of LN-nRF from LN-cRF (AUROC = 0.83). Diffusion-weighted imaging was only sensitive to LN-cRF in ME tissue (ADC, -12%; P < 0.05). CONCLUSIONS: Lupus nephritis with normal renal function first arises in MRE and BOLD images within ME tissue, progressing to CoI tissue once renal function becomes impaired and diffusion of tissue water changes.

Authors: S. R. Marticorena Garcia, M. Grossmann, A. Bruns, M. Durr, H. Tzschatzsch, B. Hamm, J. Braun, I. Sack, J. Guo

Date Published: 18th Sep 2018

Publication Type: Journal

Toward Community Standards and Software for Whole-Cell Modeling.

Abstract (Expand)

OBJECTIVE: Whole-cell (WC) modeling is a promising tool for biological research, bioengineering, and medicine. However, substantial work remains to create accurate comprehensive models of complex cells. … METHODS: We organized the 2015 Whole-Cell Modeling Summer School to teach WC modeling and evaluate the need for new WC modeling standards and software by recoding a recently published WC model in the Systems Biology Markup Language. RESULTS: Our analysis revealed several challenges to representing WC models using the current standards. CONCLUSION: We, therefore, propose several new WC modeling standards, software, and databases. SIGNIFICANCE: We anticipate that these new standards and software will enable more comprehensive models.

Authors: D. Waltemath, J. R. Karr, F. T. Bergmann, V. Chelliah, M. Hucka, M. Krantz, W. Liebermeister, P. Mendes, C. J. Myers, P. Pir, B. Alaybeyoglu, N. K. Aranganathan, K. Baghalian, A. T. Bittig, P. E. Burke, M. Cantarelli, Y. H. Chew, R. S. Costa, J. Cursons, T. Czauderna, A. P. Goldberg, H. F. Gomez, J. Hahn, T. Hameri, D. F. Gardiol, D. Kazakiewicz, I. Kiselev, V. Knight-Schrijver, C. Knupfer, M. Konig, D. Lee, A. Lloret-Villas, N. Mandrik, J. K. Medley, B. Moreau, H. Naderi-Meshkin, S. K. Palaniappan, D. Priego-Espinosa, M. Scharm, M. Sharma, K. Smallbone, N. J. Stanford, J. H. Song, T. Theile, M. Tokic, N. Tomar, V. Toure, J. Uhlendorf, T. M. Varusai, L. H. Watanabe, F. Wendland, M. Wolfien, J. T. Yurkovich, Y. Zhu, A. Zardilis, A. Zhukova, F. Schreiber

Date Published: 10th Jun 2016

Publication Type: Not specified

Towards knowledge-driven cross-species extrapolation

Abstract

Not specified

Authors: Christoph Thiel, Ute Hofmann, Ahmed Ghallab, Rolf Gebhardt, Jan G. Hengstler, Lars Kuepfer

Date Published: 1st Apr 2017

Publication Type: Not specified

Towards standardization guidelines for in silico approaches in personalized medicine.

Abstract (Expand)

Despite the ever-progressing technological advances in producing data in health and clinical research, the generation of new knowledge for medical benefits through advanced analytics still lags behind … its full potential. Reasons for this obstacle are the inherent heterogeneity of data sources and the lack of broadly accepted standards. Further hurdles are associated with legal and ethical issues surrounding the use of personal/patient data across disciplines and borders. Consequently, there is a need for broadly applicable standards compliant with legal and ethical regulations that allow interpretation of heterogeneous health data through in silico methodologies to advance personalized medicine. To tackle these standardization challenges, the Horizon2020 Coordinating and Support Action EU-STANDS4PM initiated an EU-wide mapping process to evaluate strategies for data integration and data-driven in silico modelling approaches to develop standards, recommendations and guidelines for personalized medicine. A first step towards this goal is a broad stakeholder consultation process initiated by an EU-STANDS4PM workshop at the annual COMBINE meeting (COMBINE 2019 workshop report in same issue). This forum analysed the status quo of data and model standards and reflected on possibilities as well as challenges for cross-domain data integration to facilitate in silico modelling approaches for personalized medicine.

Authors: S. Brunak, C. Bjerre Collin, K. Eva O Cathaoir, M. Golebiewski, M. Kirschner, I. Kockum, H. Moser, D. Waltemath

Date Published: 24th Jul 2020

Publication Type: Journal

Transcription factor TRIM33 controls liver progenitor cell towards hepatocyte differentiation through synergizing with phosphorylated Smad2/3 in liver cirrhosis

Abstract

Not specified

Authors: T Lin, S Wang, C Shao, X Yuan, F Wandrer, H Bantel, MP Ebert, H Ding, S Dooley, HL Weng

Date Published: 2019

Publication Type: Not specified

Transcriptomic Cross‐Species Analysis of Chronic Liver Disease Reveals Consistent Regulation Between Humans and Mice

Abstract

Not specified

Authors: Christian H. Holland, Ricardo O. Ramirez Flores, Maiju Myllys, Reham Hassan, Karolina Edlund, Ute Hofmann, Rosemarie Marchan, Cristina Cadenas, Jörg Reinders, Stefan Hoehme, Abdel‐latif Seddek, Steven Dooley, Verena Keitel, Patricio Godoy, Brigitte Begher‐Tibbe, Christian Trautwein, Christian Rupp, Sebastian Mueller, Thomas Longerich, Jan G. Hengstler, Julio Saez‐Rodriguez, Ahmed Ghallab

Date Published: 28th Aug 2021

Publication Type: Journal

Transfer of regulatory knowledge from human to mouse for functional genomics analysis

Abstract (Expand)

Transcriptome profiling followed by differential gene expression analysis often leads to lists of genes that are hard to analyze and interpret. Functional genomics tools are powerful approaches for … downstream analysis, as they summarize the large and noisy gene expression space into a smaller number of biological meaningful features. In particular, methods that estimate the activity of processes by mapping transcripts level to process members are popular. However, footprints of either a pathway or transcription factor (TF) on gene expression show superior performance over mapping-based gene sets. These footprints are largely developed for humans and their usability in the broadly-used model organism Mus musculus is uncertain. Evolutionary conservation of the gene regulatory system suggests that footprints of human pathways and TFs can functionally characterize mice data. In this paper we analyze this hypothesis. We perform a comprehensive benchmark study exploiting two state-of-the-art footprint methods, DoRothEA and an extended version of PROGENy. These methods infer TF and pathway activity, respectively. Our results show that both can recover mouse perturbations, confirming our hypothesis that footprints are conserved between mice and humans. Subsequently, we illustrate the usability of PROGENy and DoRothEA by recovering pathway/TF-disease associations from newly generated disease sets. Additionally, we provide pathway and TF activity scores for a large collection of human and mouse perturbation and disease experiments (2374). We believe that this resource, available for interactive exploration and download (https://saezlab.shinyapps.io/footprint_scores/), can have broad applications including the study of diseases and therapeutics.

Authors: Christian H. Holland, Bence Szalai, Julio Saez-Rodriguez

Date Published: 1st Sep 2019

Publication Type: Not specified

Transforming growth factor β latency: A mechanism of cytokine storage and signalling regulation in liver homeostasis and disease

Abstract

Not specified

Authors: Yujia Li, Weiguo Fan, Frederik Link, Sai Wang, Steven Dooley

Date Published: 1st Feb 2022

Publication Type: Journal

Transforming Growth Factor β1 (TGF-β1) Activates Hepcidin mRNA Expression in Hepatocytes

Abstract

Not specified

Authors: Simeng Chen, Teng Feng, Maja Vujić Spasić, Sandro Altamura, Katja Breitkopf-Heinlein, Jutta Altenöder, Thomas S. Weiss, Steven Dooley, Martina U. Muckenthaler

Date Published: 17th Jun 2016

Publication Type: Not specified

Transient elastography for screening of liver fibrosis: Cost-effectiveness analysis from six prospective cohorts in Europe and Asia.

Abstract (Expand)

BACKGROUND & AIMS: Non-alcoholic fatty liver disease and alcohol-related liver disease pose an important challenge to current clinical healthcare pathways because of the large number of at-risk … patients. Therefore, we aimed to explore the cost-effectiveness of transient elastography (TE) as a screening method to detect liver fibrosis in a primary care pathway. METHODS: Cost-effectiveness analysis was performed using real-life individual patient data from 6 independent prospective cohorts (5 from Europe and 1 from Asia). A diagnostic algorithm with conditional inference trees was developed to explore the relationships between liver stiffness, socio-demographics, comorbidities, and hepatic fibrosis, the latter assessed by fibrosis scores (FIB-4, NFS) and liver biopsies in a subset of 352 patients. We compared the incremental cost-effectiveness of a screening strategy against standard of care alongside the numbers needed to screen to diagnose a patient with fibrosis stage >/=F2. RESULTS: The data set encompassed 6,295 participants (mean age 55+/-12years, BMI 27+/-5kg/m(2), liver stiffness 5.6+/-5.0kPa). A 9.1kPa TE cut-off provided the best accuracy for the diagnosis of significant fibrosis (>/=F2) in general population settings, whereas a threshold of 9.5kPa was optimal for populations at-risk of alcohol-related liver disease. TE with the proposed cut-offs outperformed fibrosis scores in terms of accuracy. Screening with TE was cost-effective with mean incremental cost-effectiveness ratios ranging from 2,570 euro/QALY (95% CI 2,456-2,683) for a population at-risk of alcohol-related liver disease (age >/=45years) to 6,217 euro/QALY (95% CI 5,832-6,601) in the general population. Overall, there was a 12% chance of TE screening being cost saving across countries and populations. CONCLUSIONS: Screening for liver fibrosis with TE in primary care is a cost-effective intervention for European and Asian populations and may even be cost saving. LAY SUMMARY: The lack of optimized public health screening strategies for the detection of liver fibrosis in adults without known liver disease presents a major healthcare challenge. Analyses from 6 independent international cohorts, with transient elastography measurements, show that a community-based risk-stratification strategy for alcohol-related and non-alcoholic fatty liver diseases is cost-effective and potentially cost saving for our healthcare systems, as it leads to earlier identification of patients.

Authors: M. Serra-Burriel, I. Graupera, P. Toran, M. Thiele, D. Roulot, V. Wai-Sun Wong, I. Neil Guha, N. Fabrellas, A. Arslanow, C. Exposito, R. Hernandez, G. Lai-Hung Wong, D. Harman, S. Darwish Murad, A. Krag, G. Pera, P. Angeli, P. Galle, G. P. Aithal, L. Caballeria, L. Castera, P. Gines, F. Lammert

Date Published: 31st Aug 2019

Publication Type: Not specified

Translational learning from clinical studies predicts drug pharmacokinetics across patient populations

Abstract

Not specified

Authors: Markus Krauss, Ute Hofmann, Clemens Schafmayer, Svitlana Igel, Jan Schlender, Christian Mueller, Mario Brosch, Witigo von Schoenfels, Wiebke Erhart, Andreas Schuppert, Michael Block, Elke Schaeffeler, Gabriele Boehmer, Linus Goerlitz, Jan Hoecker, Joerg Lippert, Reinhold Kerb, Jochen Hampe, Lars Kuepfer, Matthias Schwab

Date Published: 1st Dec 2017

Publication Type: Not specified

Translational learning from clinical studies predicts drug pharmacokinetics across patient populations.

Abstract (Expand)

Early indication of late-stage failure of novel candidate drugs could be facilitated by continuous integration, assessment, and transfer of knowledge acquired along pharmaceutical development programs. … We here present a translational systems pharmacology workflow that combines drug cocktail probing in a specifically designed clinical study, physiologically based pharmacokinetic modeling, and Bayesian statistics to identify and transfer (patho-)physiological and drug-specific knowledge across distinct patient populations. Our work builds on two clinical investigations, one with 103 healthy volunteers and one with 79 diseased patients from which we systematically derived physiological information from pharmacokinetic data for a reference probe drug (midazolam) at the single-patient level. Taking into account the acquired knowledge describing (patho-)physiological alterations in the patient cohort allowed the successful prediction of the population pharmacokinetics of a second, candidate probe drug (torsemide) in the patient population. In addition, we identified significant relations of the acquired physiological processes to patient metadata from liver biopsies. The presented prototypical systems pharmacology approach is a proof of concept for model-based translation across different stages of pharmaceutical development programs. Applied consistently, it has the potential to systematically improve predictivity of pharmacokinetic simulations by incorporating the results of clinical trials and translating them to subsequent studies.

Authors: M. Krauss, U. Hofmann, C. Schafmayer, S. Igel, J. Schlender, C. Mueller, M. Brosch, W. von Schoenfels, W. Erhart, A. Schuppert, M. Block, E. Schaeffeler, G. Boehmer, L. Goerlitz, J. Hoecker, J. Lippert, R. Kerb, J. Hampe, L. Kuepfer, M. Schwab

Date Published: 27th Jun 2017

Publication Type: Not specified

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

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

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