Filter and export

Publications

What is a Publication?
18 Publications visible to you, out of a total of 18
Basal MET phosphorylation is an indicator of hepatocyte dysregulation in liver disease

Abstract (Expand)

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

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

Date Published: 12th Jan 2024

Publication Type: Journal

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

Abstract (Expand)

The Hedgehog signaling pathway regulates many processes during embryogenesis and the homeostasis of adult organs. Recent data suggest that central metabolic processes and signaling cascades in the liver … 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

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

Abstract (Expand)

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

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

Date Published: 1st May 2022

Publication Type: Journal

In Vivo and In Vitro Characterization of Primary Human Liver Macrophages and Their Inflammatory State

Abstract (Expand)

Liver macrophages (LMs) play a central role in acute and chronic liver pathologies. Investigation of these processes in humans as well as the development of diagnostic tools and new therapeutic strategies … require in vitro models that closely resemble the in vivo situation. In our study, we sought to gain further insight into the role of LMs in different liver pathologies and into their characteristics after isolation from liver tissue. For this purpose, LMs were characterized in human liver tissue sections using immunohistochemistry and bioinformatic image analysis. Isolated cells were characterized in suspension using FACS analyses and in culture using immunofluorescence staining and laser scanning microscopy as well as functional assays. The majority of our investigated liver tissues were characterized by anti-inflammatory LMs which showed a homogeneous distribution and increased cell numbers in correlation with chronic liver injuries. In contrast, pro-inflammatory LMs appeared as temporary and locally restricted reactions. Detailed characterization of isolated macrophages revealed a complex disease dependent pattern of LMs consisting of pro- and anti-inflammatory macrophages of different origins, regulatory macrophages and monocytes. Our study showed that in most cases the macrophage pattern can be transferred in adherent cultures. The observed exceptions were restricted to LMs with pro-inflammatory characteristics.

Authors: Andrea Zimmermann, René Hänsel, Kilian Gemünden, Victoria Kegel-Hübner, Jonas Babel, Hendrik Bläker, Madlen Matz-Soja, Daniel Seehofer, Georg Damm

Date Published: 1st Apr 2021

Publication Type: Journal

Chronic Disruption of the Late Cholesterol Synthesis Leads to Female-Prevalent Liver Cancer.

Abstract (Expand)

While the role of cholesterol in liver carcinogenesis remains controversial, hepatocellular carcinoma generally prevails in males. Herein, we uncover pathways of female-prevalent progression to … hepatocellular carcinoma due to chronic repression of cholesterogenic lanosterol 14alpha-demethylase (CYP51) in hepatocytes. Tumors develop in knock-out mice after year one, with 2:1 prevalence in females. Metabolic and transcription factor networks were deduced from the liver transcriptome data, combined by sterol metabolite and blood parameter analyses, and interpreted with relevance to humans. Female knock-outs show increased plasma cholesterol and HDL, dampened lipid-related transcription factors FXR, LXRalpha:RXRalpha, and importantly, crosstalk between reduced LXRalpha and activated TGF-beta signalling, indicating a higher susceptibility to HCC in aging females. PI3K/Akt signalling and ECM-receptor interaction are common pathways that are disturbed by sex-specific altered genes. Additionally, transcription factors (SOX9)2 and PPARalpha were recognized as important for female hepatocarcinogenesis, while overexpressed Cd36, a target of nuclear receptor RORC, is a new male-related regulator of ECM-receptor signalling in hepatocarcinogenesis. In conclusion, we uncover the sex-dependent metabolic reprogramming of cholesterol-related pathways that predispose for hepatocarcinogenesis in aging females. This is important in light of increased incidence of liver cancers in post-menopausal women.

Authors: K. B. Cokan, Z. Urlep, G. Lorbek, M. Matz-Soja, C. Skubic, M. Perse, J. Jeruc, P. Juvan, T. Rezen, D. Rozman

Date Published: 9th Nov 2020

Publication Type: Journal

Cyclopamine and Rapamycin Synergistically Inhibit mTOR Signalling in Mouse Hepatocytes, Revealing an Interaction of Hedgehog and mTor Signalling in the Liver

Abstract (Expand)

In the liver, energy homeostasis is mainly regulated by mechanistic target of rapamycin (mTOR) signalling, which influences relevant metabolic pathways, including lipid metabolism. However, the Hedgehog … (Hh) pathway is one of the newly identified drivers of hepatic lipid metabolism. Although the link between mTOR and Hh signalling was previously demonstrated in cancer development and progression, knowledge of their molecular crosstalk in healthy liver is lacking. To close this information gap, we used a transgenic mouse model, which allows hepatocyte-specific deletion of the Hh pathway, and in vitro studies to reveal interactions between Hh and mTOR signalling. The study was conducted in male and female mice to investigate sexual differences in the crosstalk of these signalling pathways. Our results reveal that the conditional Hh knockout reduces mitochondrial adenosine triphosphate (ATP) production in primary hepatocytes from female mice and inhibits autophagy in hepatocytes from both sexes. Furthermore, in vitro studies show a synergistic effect of cyclopamine and rapamycin on the inhibition of mTor signalling and oxidative respiration in primary hepatocytes from male and female C57BL/6N mice. Overall, our results demonstrate that the impairment of Hh signalling influences mTOR signalling and therefore represses oxidative phosphorylation and autophagy.

Authors: Luise Spormann, Christiane Rennert, Erik Kolbe, Fritzi Ott, Carolin Lossius, Robert Lehmann, Rolf Gebhardt, Thomas Berg, Madlen Matz-Soja

Date Published: 1st Aug 2020

Publication Type: Journal

Loss of hepatic Mboat7 leads to liver fibrosis.

Abstract (Expand)

OBJECTIVE: The rs641738C>T variant located near the membrane-bound O-acyltransferase domain containing 7 (MBOAT7) locus is associated with fibrosis in liver diseases, including non-alcoholic fatty … liver disease (NAFLD), alcohol-related liver disease, hepatitis B and C. We aim to understand the mechanism by which the rs641738C>T variant contributes to pathogenesis of NAFLD. DESIGN: Mice with hepatocyte-specific deletion of MBOAT7 (Mboat7(Deltahep)) were generated and livers were characterised by histology, flow cytometry, qPCR, RNA sequencing and lipidomics. We analysed the association of rs641738C>T genotype with liver inflammation and fibrosis in 846 NAFLD patients and obtained genotype-specific liver lipidomes from 280 human biopsies. RESULTS: Allelic imbalance analysis of heterozygous human liver samples pointed to lower expression of the MBOAT7 transcript on the rs641738C>T haplotype. Mboat7(Deltahep) mice showed spontaneous steatosis characterised by increased hepatic cholesterol ester content after 10 weeks. After 6 weeks on a high fat, methionine-low, choline-deficient diet, mice developed increased hepatic fibrosis as measured by picrosirius staining (p<0.05), hydroxyproline content (p<0.05) and transcriptomics, while the inflammatory cell populations and inflammatory mediators were minimally affected. In a human biopsied NAFLD cohort, MBOAT7 rs641738C>T was associated with fibrosis (p=0.004) independent of the presence of histological inflammation. Liver lipidomes of Mboat7(Deltahep) mice and human rs641738TT carriers with fibrosis showed increased total lysophosphatidylinositol levels. The altered lysophosphatidylinositol and phosphatidylinositol subspecies in MBOAT7(Deltahep) livers and human rs641738TT carriers were similar. CONCLUSION: Mboat7 deficiency in mice and human points to an inflammation-independent pathway of liver fibrosis that may be mediated by lipid signalling and a potentially targetable treatment option in NAFLD.

Authors: V. R. Thangapandi, O. Knittelfelder, M. Brosch, E. Patsenker, O. Vvedenskaya, S. Buch, S. Hinz, A. Hendricks, M. Nati, A. Herrmann, D. R. Rekhade, T. Berg, M. Matz-Soja, K. Huse, E. Klipp, J. K. Pauling, J. A. Wodke, J. Miranda Ackerman, M. V. Bonin, E. Aigner, C. Datz, W. von Schonfels, S. Nehring, S. Zeissig, C. Rocken, A. Dahl, T. Chavakis, F. Stickel, A. Shevchenko, C. Schafmayer, J. Hampe, P. Subramanian

Date Published: 26th Jun 2020

Publication Type: Journal

Functional consequences of metabolic zonation in murine livers: New insights for an old story.

Abstract (Expand)

BACKGROUND & AIMS: Zone-dependent differences in the expression of metabolic enzymes along the porto-central axis of the acinus are a long-known feature of liver metabolism. A prominent example is … the preferential localization of the enzyme glutamine synthetase in pericentral hepatocytes, where it converts potentially toxic ammonia to the valuable amino acid glutamine. However, with the exception of a few key regulatory enzymes, a comprehensive and quantitative assessment of zonal differences in the abundance of metabolic enzymes and much more importantly, an estimation of the associated functional differences between portal and central hepatocytes is missing thus far. APPROACH & RESULTS: We addressed this problem by establishing a new method for the separation of periportal and pericentral hepatocytes that yields sufficiently pure fractions of both cell populations. Quantitative shotgun proteomics identified hundreds of differentially expressed enzymes in the two cell populations. We used zone-specific proteomics data for scaling of the maximal activities to generate portal and central instantiations of a comprehensive kinetic model of central hepatic metabolism (Hepatokin1). CONCLUSION: The model simulations revealed significant portal-to-central differences in almost all metabolic pathways involving carbohydrates, fatty acids, amino acids and detoxification.

Authors: N. Berndt, E. Kolbe, R. Gajowski, J. Eckstein, F. Ott, D. Meierhofer, H. G. Holzhutter, M. Matz-Soja

Date Published: 14th Apr 2020

Publication Type: Not specified

Influence of Liver Fibrosis on Lobular Zonation

Abstract (Expand)

Little is known about how liver fibrosis influences lobular zonation. To address this question, we used three mouse models of liver fibrosis, repeated CCl4 administration for 2, 6 and 12 months to … induce pericentral damage, as well as bile duct ligation (21 days) and mdr2−/− mice to study periportal fibrosis. Analyses were performed by RNA-sequencing, immunostaining of zonated proteins and image analysis. RNA-sequencing demonstrated a significant enrichment of pericentral genes among genes downregulated by CCl4; vice versa, periportal genes were enriched among the upregulated genes. Immunostaining showed an almost complete loss of pericentral proteins, such as cytochrome P450 enzymes and glutamine synthetase, while periportal proteins, such as arginase 1 and CPS1 became expressed also in pericentral hepatocytes. This pattern of fibrosis-associated ‘periportalization’ was consistently observed in all three mouse models and led to complete resistance to hepatotoxic doses of acetaminophen (200 mg/kg). Characterization of the expression response identified the inflammatory pathways TGFβ, NFκB, TNFα, and transcription factors NFKb1, Stat1, Hif1a, Trp53, and Atf1 among those activated, while estrogen-associated pathways, Hnf4a and Hnf1a, were decreased. In conclusion, liver fibrosis leads to strong alterations of lobular zonation, where the pericentral region adopts periportal features. Beside adverse consequences, periportalization supports adaptation to repeated doses of hepatotoxic compounds.

Authors: Ahmed Ghallab, Maiju Myllys, Christian Holland, Ayham Zaza, Walaa Murad, Reham Hassan, Yasser A Ahmed, Tahany Abbas, Eman Abdelrahim, Kai Markus Schneider, Madlen Matz-Soja, Joerg Reinders, Rolf Gebhardt, Theresa Hildegard Wirtz, Maximilian Hatting, Dirk Drasdo, Julio Saez-Rodriguez, Christian Trautwein, Jan Hengstler

Date Published: 1st Dec 2019

Publication Type: Not specified

Mutual Zonated Interactions of Wnt and Hh Signaling Are Orchestrating the Metabolism of the Adult Liver in Mice and Human

Abstract (Expand)

The Hedgehog (Hh) and Wnt/β-Catenin (Wnt) cascades are morphogen pathways whose pronounced influence on adult liver metabolism has been identified in recent years. How both pathways communicate and … control liver metabolic functions are largely unknown. Detecting core components of Wnt and Hh signaling and mathematical modeling showed that both pathways in healthy liver act largely complementary to each other in the pericentral (Wnt) and the periportal zone (Hh) and communicate mainly by mutual repression. The Wnt/Hh module inversely controls the spatiotemporal operation of various liver metabolic pathways, as revealed by transcriptome, proteome, and metabolome analyses. Shifting the balance to Wnt (activation) or Hh (inhibition) causes pericentralization and periportalization of liver functions, respectively. Thus, homeostasis of the Wnt/Hh module is essential for maintaining proper liver metabolism and to avoid the development of certain metabolic diseases. With caution due to minor species-specific differences, these conclusions may hold for human liver as well.

Authors: Erik Kolbe, Susanne Aleithe, Christiane Rennert, Luise Spormann, Fritzi Ott, David Meierhofer, Robert Gajowski, Claus Stöpel, Stefan Hoehme, Michael Kücken, Lutz Brusch, Michael Seifert, Witigo von Schoenfels, Clemens Schafmayer, Mario Brosch, Ute Hofmann, Georg Damm, Daniel Seehofer, Jochen Hampe, Rolf Gebhardt, Madlen Matz-Soja

Date Published: 1st Dec 2019

Publication Type: Not specified

beta-Catenin and Yes-Associated Protein 1 Cooperate in Hepatoblastoma Pathogenesis.

Abstract (Expand)

Hepatoblastoma (HB), the most common pediatric primary liver neoplasm, shows nuclear localization of beta-catenin and yes-associated protein 1 (YAP1) in almost 80% of the cases. Co-expression of … constitutively active S127A-YAP1 and DeltaN90 deletion-mutant beta-catenin (YAP1-DeltaN90-beta-catenin) causes HB in mice. Because heterogeneity in downstream signaling is being identified owing to mutational differences even in the beta-catenin gene alone, we investigated if co-expression of point mutants of beta-catenin (S33Y or S45Y) with S127A-YAP1 led to similar tumors as YAP1-DeltaN90-beta-catenin. Co-expression of S33Y/S45Y-beta-catenin and S127A-YAP1 led to activation of Yap and Wnt signaling and development of HB, with 100% mortality by 13 to 14 weeks. Co-expression with YAP1-S45Y/S33Y-beta-catenin of the dominant-negative T-cell factor 4 or dominant-negative transcriptional enhanced associate domain 2, the respective surrogate transcription factors, prevented HB development. Although histologically similar, HB in YAP1-S45Y/S33Y-beta-catenin, unlike YAP1-DeltaN90-beta-catenin HB, was glutamine synthetase (GS) positive. However, both DeltaN90-beta-catenin and point-mutant beta-catenin comparably induced GS-luciferase reporter in vitro. Finally, using a previously reported 16-gene signature, it was shown that YAP1-DeltaN90-beta-catenin HB tumors exhibited genetic similarities with more proliferative, less differentiated, GS-negative HB patient tumors, whereas YAP1-S33Y/S45Y-beta-catenin HB exhibited heterogeneity and clustered with both well-differentiated GS-positive and proliferative GS-negative patient tumors. Thus, we demonstrate that beta-catenin point mutants can also collaborate with YAP1 in HB development, albeit with a distinct molecular profile from the deletion mutant, which may have implications in both biology and therapy.

Authors: Q. Min, L. Molina, J. Li, A. O. Adebayo Michael, J. O. Russell, M. E. Preziosi, S. Singh, M. Poddar, M. Matz-Soja, S. Ranganathan, A. W. Bell, R. Gebhardt, F. Gaunitz, J. Yu, J. Tao, S. P. Monga

Date Published: 23rd Feb 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

Epigenomic map of human liver reveals principles of zonated morphogenic and metabolic control

Abstract

Not specified

Authors: Mario Brosch, Kathrin Kattler, Alexander Herrmann, Witigo von Schönfels, Karl Nordström, Daniel Seehofer, Georg Damm, Thomas Becker, Sebastian Zeissig, Sophie Nehring, Fabian Reichel, Vincent Moser, Raghavan Veera Thangapandi, Felix Stickel, Gustavo Baretton, Christoph Röcken, Michael Muders, Madlen Matz-Soja, Michael Krawczak, Gilles Gasparoni, Hella Hartmann, Andreas Dahl, Clemens Schafmayer, Jörn Walter, Jochen Hampe

Date Published: 1st Dec 2018

Publication Type: Not specified

Epigenomic map of human liver reveals principles of zonated morphogenic and metabolic control

Abstract (Expand)

A deeper epigenomic understanding of spatial organization of cells in human tissues is an important challenge. Here we report the first combined positional analysis of transcriptomes and methylomes … across three micro-dissected zones (pericentral, intermediate and periportal) of human liver. We identify pronounced anti-correlated transcriptional and methylation gradients including a core of 271 genes controlling zonated metabolic and morphogen networks and observe a prominent porto-central gradient of DNA methylation at binding sites of 46 transcription factors. The gradient includes an epigenetic and transcriptional Wnt signature supporting the concept of a pericentral hepatocyte regeneration pathway under steady-state conditions. While donors with non-alcoholic fatty liver disease show consistent gene expression differences corresponding to the severity of the disease across all zones, the relative zonated gene expression and DNA methylation patterns remain unchanged. Overall our data provide a wealth of new positional insights into zonal networks controlled by epigenetic and transcriptional gradients in human liver.

Authors: Mario Brosch, Kathrin Kattler, Alexander Herrmann, Witigo von Schönfels, Karl Nordström, Daniel Seehofer, Georg Damm, Thomas Becker, Sebastian Zeissig, Sophie Nehring, Fabian Reichel, Vincent Moser, Raghavan Veera Thangapandi, Felix Stickel, Gustavo Baretton, Christoph Röcken, Michael Muders, Madlen Matz-Soja, Michael Krawczak, Gilles Gasparoni, Hella Hartmann, Andreas Dahl, Clemens Schafmayer, Jörn Walter, Jochen Hampe

Date Published: 1st Dec 2018

Publication Type: Not specified

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

Computational modelling of Hedgehog signalling in liver regeneration

Abstract (Expand)

Organ regeneration is a very complex process that includes not only the reconstruction of organ mass but also the reorganisation of homeostatic capabilities. This especially applies for the liver, which … performs a variety of metabolic functions. In the last decade, morphogenic pathways such as the Wnt/β-Catenin and Hedgehog signalling pathways have been revealed to orchestrate liver regeneration as well as metabolism. Mathematical models have been successfully applied to liver regeneration, but these have not integrated the Hedgehog signalling pathway. In this review it is tried to compile features of Hh signalling in liver regeneration which can be integrated into liver regeneration modeling.

Author: Madlen Matz-Soja

Date Published: 1st Jul 2017

Publication Type: Not specified

Conditional loss of hepatocellular Hedgehog signaling in female mice leads to the persistence of hepatic steroidogenesis, androgenization and infertility

Abstract (Expand)

The Hedgehog signaling pathway is known to be involved in embryogenesis, tissue remodeling, and carcinogenesis. Because of its involvement in carcinogenesis, it seems an interesting target for cancer … therapy. Indeed, Sonidegib, an approved inhibitor of the Hedgehog receptor Smoothened (Smo), is highly active against diverse carcinomas, but its use is also reported to be associated with several systemic side effects. Our former work in adult mice demonstrated hepatic Hedgehog signaling to play a key role in the insulin-like growth factor axis and lipid metabolism. The current work using mice with an embryonic and hepatocyte-specific Smo deletion describes an adverse impact of the hepatic Hedgehog pathway on female fertility. In female SAC-KO mice, we detected androgenization characterized by a 3.3-fold increase in testosterone at 12 weeks of age based on an impressive induction of steroidogenic gene expression in hepatocytes, but not in the classic steroidogenic organs (ovary and adrenal gland). Along with the elevated level of testosterone, the female SAC-KO mice showed infertility characterized by juvenile reproductive organs and acyclicity. The endocrine and reproductive alterations resembled polycystic ovarian syndrome and could be confirmed in a second mouse model with conditional deletion of Smo at 8 weeks of age after an extended period of 8 months. We conclude that the down-regulation of hepatic Hedgehog signaling leads to an impaired hormonal balance by the induction of steroidogenesis in the liver. These effects of Hedgehog signaling inhibition should be considered when using Hedgehog inhibitors as anti-cancer drugs.

Authors: Christiane Rennert, Franziska Eplinius, Ute Hofmann, Janina Johänning, Franziska Rolfs, Wolfgang Schmidt-Heck, Reinhardt Guthke, Rolf Gebhardt, Albert M. Ricken, Madlen Matz-Soja

Date Published: 30th May 2017

Publication Type: Not specified

Hedgehog signaling is a potent regulator of liver lipid metabolism and reveals a GLI-code associated with steatosis.

Abstract (Expand)

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease in industrialized countries and is increasing in prevalence. The pathomechanisms, however, are poorly understood. This study … assessed the unexpected role of the Hedgehog pathway in adult liver lipid metabolism. Using transgenic mice with conditional hepatocyte-specific deletion of Smoothened in adult mice, we showed that hepatocellular inhibition of Hedgehog signaling leads to steatosis by altering the abundance of the transcription factors GLI1 and GLI3. This steatotic 'Gli-code' caused the modulation of a complex network of lipogenic transcription factors and enzymes, including SREBP1 and PNPLA3, as demonstrated by microarray analysis and siRNA experiments and could be confirmed in other steatotic mouse models as well as in steatotic human livers. Conversely, activation of the Hedgehog pathway reversed the "Gli-code" and mitigated hepatic steatosis. Collectively, our results reveal that dysfunctions in the Hedgehog pathway play an important role in hepatic steatosis and beyond.

Authors: M. Matz-Soja, C. Rennert, K. Schonefeld, S. Aleithe, J. Boettger, W. Schmidt-Heck, T. S. Weiss, A. Hovhannisyan, S. Zellmer, N. Kloting, A. Schulz, J. Kratzsch, R. Guthke, R. Gebhardt

Date Published: 17th May 2016

Publication Type: Not specified

Powered by
 (v.1.15.2)
About FAIRDOM | About LiSyM | Funding and Programmes | Credits | Terms & Conditions | Imprint
Copyright © 2008 - 2024 The University of Manchester and HITS gGmbH