Publications

What is a Publication?
40 Publications visible to you, out of a total of 40

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

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

Abstract

Not specified

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

Date Published: 2023

Publication Type: Journal

Abstract

Not specified

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

Date Published: 2023

Publication Type: Journal

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

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

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 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: F. Ott, C. Korner, K. Werner, M. Gericke, I. Liebscher, D. Lobsien, S. Radrezza, A. Shevchenko, U. Hofmann, J. Kratzsch, R. Gebhardt, T. Berg, M. Matz-Soja

Date Published: 18th May 2022

Publication Type: Journal

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 livers 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

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 isrge 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

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 ), rs2642438rotein 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

Powered by
(v.1.14.2)
Copyright © 2008 - 2023 The University of Manchester and HITS gGmbH