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79 Publications visible to you, out of a total of 79

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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

Abstract (Expand)

Human plasma lipidome has been extensively studied in many pathophysiological contexts with the hope of identifying biomarkers for early diagnostics and monitoring the progression and treatment of a broad spectrum of diseases. However, despite remarkable progress in lipidomics technologies, the concordance of lipidomics measurements between independent laboratories remains limited and not fulfilling the criteria of common laboratory diagnostics. Here we highlighted a few critical aspects of epidemiological studies of the plasma lipidome, including the selection of study cohorts, collection of plasma samples as well as extraction, identification and quantification of lipids. We argue that reporting the abundances of plasma lipids as molar concentrations is a key turning point during the transition of research lipidomics into a common tool of clinical diagnostics.

Authors: Olga Vvedenskaya, Yuting Wang, Jacobo Miranda Ackerman, Oskar Knittelfelder, Andrej Shevchenko

Date Published: 20th Oct 2018

Publication Type: Not specified

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OBJECTIVES: Variants in patatin-like phospholipase domain-containing 3 (PNPLA3; rs738409), transmembrane 6 superfamily member 2 (TM6SF2; rs58542926), and membrane bound O-acyltransferase domain containingg 7 (MBOAT7; rs641738) are risk factors for the development of alcohol-related cirrhosis. Within this population, PNPLA3 rs738409 is also an established risk factor for the development of hepatocellular carcinoma (HCC). The aim of this study was to explore possible risk associations of TM6SF2 rs58542926 and MBOAT7 rs641738 with HCC. METHODS: Risk variants in PNPLA3, TM6SF2, and MBOAT7 were genotyped in 751 cases with alcohol-related cirrhosis and HCC and in 1165 controls with alcohol-related cirrhosis without HCC. Association with the risk of developing HCC was analyzed using multivariate logistic regression. RESULTS: The development of HCC was independently associated with PNPLA3 rs738409 (ORadjusted 1.84 [95% CI 1.55-2.18], p = 1.85 × 10-12) and TM6SF2 rs58542926 (ORadjusted 1.66 [1.30-2.13], p = 5.13 × 10-05), using an additive model, and controlling the sex, age, body mass index, and type 2 diabetes mellitus; the risk associated with carriage of MBOAT7 rs641738 (ORadjusted 1.04 [0.88-1.24], p = 0.61) was not significant. The population-attributable fractions were 43.5% for PNPLA3 rs738409, 11.5% for TM6SF2 rs58542926, and 49.9% for the carriage of both the variants combined. CONCLUSIONS: Carriage of TM6SF2 rs58542926 is an additional risk factor for the development of HCC in people with alcohol-related cirrhosis. Carriage of both PNPLA3 rs738409 and TM6SF2 rs58542926 accounts for half of the attributable risk for HCC in this population. Genotyping will allow for more precise HCC risk-stratification of patients with alcohol-related cirrhosis, and genotype-guided screening algorithms would optimize patient care.

Authors: Felix Stickel, Stephan Buch, Hans Dieter Nischalke, Karl Heinz Weiss, Daniel Gotthardt, Janett Fischer, Jonas Rosendahl, Astrid Marot, Mona Elamly, Markus Casper, Frank Lammert, Andrew McQuillin, Steffen Zopf, Ulrich Spengler, Silke Marhenke, Martha M. Kirstein, Arndt Vogel, Florian Eyer, Johann von Felden, Henning Wege, Thorsten Buch, Clemens Schafmayer, Felix Braun, Pierre Deltenre, Thomas Berg, Marsha Y. Morgan, Jochen Hampe

Date Published: 1st Oct 2018

Publication Type: Not specified

Abstract (Expand)

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries. Nonalcoholic steatohepatitis is the fastest growing cause for liver failure. Bariatric surgery represents a treatment option for NAFLD with an established effect on liver histology. OBJECTIVES: We aimed to assess the impact of bariatric surgery on standardized liver histology using the NAFLD activity score. SETTING: Retrospective comparison of metabolic data before and after bariatric surgery and comparison of sleeve gastrectomy and Roux-en-Y gastric bypass. The study was performed in an academic center, the university hospital Schleswig-Holstein in Kiel, Germany. METHODS: Between 2009 and 2012, bariatric surgery was performed in 257 patients according to the national guidelines, and a liver biopsy was obtained in 150 of these patients during surgery. A follow-up biopsy was available in 53 of these patients at a median of 192 days. Liver histology was analyzed using the NAFLD activity score. In this subgroup of 53 patients an analysis of the metabolic improvement after bariatric surgery and a comparative analysis between the 2 different operative procedures was performed. RESULTS: The study cohort showed improvement of preoperative pathologic liver histology findings after operative procedures took place. Both surgery methods improved the NAFLD activity score significantly, all improvement -2.0 (confidence interval -2.5 to -1.0; P < .001); Roux-en-Y gastric bypass, improvement -1.0 (confidence interval -2.0 to -.0; P=.038); sleeve gastrectomy, improvement -2.5 (confidence interval -3.5 to -1.5; P < .001). No differences were found with regard to histologic recovery between gastric bypass and sleeve gastrectomy (P = .22). CONCLUSIONS: Bariatric surgery significantly improves NAFLD.

Authors: W. von Schonfels, J. H. Beckmann, M. Ahrens, A. Hendricks, C. Rocken, S. Szymczak, J. Hampe, C. Schafmayer

Date Published: 28th Aug 2018

Publication Type: Not specified

Abstract (Expand)

OBJECTIVE: Homozygous alpha1-antitrypsin (AAT) deficiency increases the risk for developing cirrhosis, whereas the relevance of heterozygous carriage remains unclear. Hence, we evaluated the impact of the two most relevant AAT variants ('Pi*Z' and 'Pi*S'), present in up to 10% of Caucasians, on subjects with non-alcoholic fatty liver disease (NAFLD) or alcohol misuse. DESIGN: We analysed multicentric case-control cohorts consisting of 1184 people with biopsy-proven NAFLD and of 2462 people with chronic alcohol misuse, both cohorts comprising cases with cirrhosis and controls without cirrhosis. Genotyping for the Pi*Z and Pi*S variants was performed. RESULTS: The Pi*Z variant presented in 13.8% of patients with cirrhotic NAFLD but only in 2.4% of counterparts without liver fibrosis (p<0.0001). Accordingly, the Pi*Z variant increased the risk of NAFLD subjects to develop cirrhosis (adjusted OR=7.3 (95% CI 2.2 to 24.8)). Likewise, the Pi*Z variant presented in 6.2% of alcohol misusers with cirrhosis but only in 2.2% of alcohol misusers without significant liver injury (p<0.0001). Correspondingly, alcohol misusers carrying the Pi*Z variant were prone to develop cirrhosis (adjusted OR=5.8 (95% CI 2.9 to 11.7)). In contrast, the Pi*S variant was not associated with NAFLD-related cirrhosis and only borderline with alcohol-related cirrhosis (adjusted OR=1.47 (95% CI 0.99 to 2.19)). CONCLUSION: The Pi*Z variant is the hitherto strongest single nucleotide polymorphism-based risk factor for cirrhosis in NAFLD and alcohol misuse, whereas the Pi*S variant confers only a weak risk in alcohol misusers. As 2%-4% of Caucasians are Pi*Z carriers, this finding should be considered in genetic counselling of affected individuals.

Authors: P. Strnad, S. Buch, K. Hamesch, J. Fischer, J. Rosendahl, R. Schmelz, S. Brueckner, M. Brosch, C. V. Heimes, V. Woditsch, D. Scholten, H. D. Nischalke, S. Janciauskiene, M. Mandorfer, M. Trauner, M. J. Way, A. McQuillin, M. C. Reichert, M. Krawczyk, M. Casper, F. Lammert, F. Braun, W. von Schonfels, S. Hinz, G. Burmeister, C. Hellerbrand, A. Teufel, A. Feldman, J. M. Schattenberg, H. Bantel, A. Pathil, M. Demir, J. Kluwe, T. Boettler, M. Ridinger, N. Wodarz, M. Soyka, M. Rietschel, F. Kiefer, T. Weber, S. Marhenke, A. Vogel, H. Hinrichsen, A. Canbay, M. Schlattjan, K. Sosnowsky, C. Sarrazin, J. von Felden, A. Geier, P. Deltenre, B. Sipos, C. Schafmayer, M. Nothnagel, E. Aigner, C. Datz, F. Stickel, M. Y. Morgan, J. Hampe, T. Berg, C. Trautwein

Date Published: 3rd Aug 2018

Publication Type: Journal

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Shotgun analysis provides a quantitative snapshot of the lipidome composition of cells, tissues, or model organisms; however, it does not elucidate the spatial distribution of lipids. Here we demonstrate that shotgun analysis could quantify low-picomole amounts of lipids isolated by laser capture microdissection (LCM) of hundred micrometer-sized histological zones visualized at the cryosections of tissues. We identified metabolically distinct periportal (pp) and pericentral (pc) zones by immunostaining of 20 mum thick cryosections of a healthy mouse liver. LCM was used to ablate, catapult, and collect the tissue material from 10 to 20 individual zones covering a total area of 0.3-0.5 mm(2) and containing ca. 500 cells. Top-down shotgun profiling relying upon computational stitching of 61 targeted selective ion monitoring ( t-SIM) spectra quantified more than 200 lipid species from 17 lipid classes including glycero- and glycerophospholipids, sphingolipids, cholesterol esters, and cholesterol. Shotgun LCM revealed the overall commonality of the full lipidome composition of pp and pc zones along with significant ( p < 0.001) difference in the relative abundance of 13 lipid species. Follow-up proteomics analyses of pellets recovered from an aqueous phase saved after the lipid extraction identified 13 known and 7 new protein markers exclusively present in pp or in pc zones and independently validated the specificity of their visualization, isolation, and histological assignment.

Authors: O. Knittelfelder, S. Traikov, O. Vvedenskaya, A. Schuhmann, S. Segeletz, A. Shevchenko, A. Shevchenko

Date Published: 30th Jul 2018

Publication Type: Not specified

Abstract (Expand)

BACKGROUND: Liver transplantation (LTx) is a potentially curative treatment option for hepatocellular carcinoma (HCC) in cirrhosis. However, patients, where HCC is already a systemic disease, LTx may be individually harmful and has a negative impact on donor organ usage. Thus, there is a need for improved selection criteria beyond nodule morphology to select patients with a favorable outcome for LTx in multifocal HCC. Evolutionary distance measured from genome-wide single-nucleotide polymorphism data between tumor nodules and the cirrhotic liver may be a prognostic marker of survival after LTx for multifocal HCC. METHODS: In a retrospective multicenter study, clinical data and formalin-fixed paraffin-embedded specimens of the liver and 2 tumor nodules were obtained from explants of 30 patients in the discovery and 180 patients in the replication cohort. DNA was extracted from formalin-fixed paraffin-embedded specimens followed by genome wide single-nucleotide polymorphism genotyping. RESULTS: Genotype quality criteria allowed for analysis of 8 patients in the discovery and 17 patients in the replication set. DNA concentrations of a total of 25 patients fulfilled the quality criteria and were included in the analysis. Both, in the discovery (P = 0.04) and in the replication data sets (P = 0.01), evolutionary distance was associated with the risk of recurrence of HCC after transplantation (combined P = 0.0002). In a univariate analysis, evolutionary distance (P = 7.4 x 10) and microvascular invasion (P = 1.31 x 10) were significantly associated with survival in a Cox regression analysis. CONCLUSIONS: Evolutionary distance allows for the determination of a high-risk group of recurrence if preoperative liver biopsy is considered.

Authors: N. Heits, M. Brosch, A. Herrmann, R. Behrens, C. Rocken, H. Schrem, A. Kaltenborn, J. Klempnauer, H. H. Kreipe, B. Reichert, C. Lenschow, C. Wilms, T. Vogel, H. Wolters, E. Wardelmann, D. Seehofer, S. Buch, S. Zeissig, S. Pannach, N. Raschzok, M. Dietel, W. von Schoenfels, S. Hinz, A. Teufel, M. Evert, A. Franke, T. Becker, F. Braun, J. Hampe, C. Schafmayer

Date Published: 12th Jul 2018

Publication Type: Not specified

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

Abstract (Expand)

The solute carrier (SLC) SLC16 gene family comprises 14 members and encodes for monocarboxylate transporters (MCTs), which mediate the absorption and distribution of monocarboxylic compounds across plasma membranes. As the knowledge about their physiological function, activity, and regulation increases, their involvement and contribution to cancer and other diseases become increasingly evident. Moreover, promising opportunities for therapeutic interventions by directly targeting their endogenous functions or by exploiting their ability to deliver drugs to specific organ sites emerge.

Authors: P. Fisel, E. Schaeffeler, M. Schwab

Date Published: 17th Apr 2018

Publication Type: Not specified

Abstract (Expand)

Neurotoxic bilirubin is the end product of heme catabolism in mammals. Bilirubin is solely conjugated by uridine diphospho-glucuronosyltransferase 1A1, which is a membrane-bound enzyme that catalyzes the transfer of glucuronic acid. Due to low function of hepatic and intestinal uridine diphospho-glucuronosyltransferase 1A1 during the neonatal period, human neonates develop mild to severe physiological hyperbilirubinemia. Accumulation of bilirubin in the brain leads to the onset of irreversible brain damage, termed kernicterus. Breastfeeding is one of the most significant factors that increase the risk of developing kernicterus in infants. Why does this most natural way of feeding increase the risk of brain damage or even death? This question leads to the hypothesis that breast milk-induced hyperbilirubinemia might bring certain benefits that outweigh those risks. While bilirubin is neurotoxic and cytotoxic, this compound is also a potent antioxidant. There are studies showing improved clinical conditions in patients with hyperbilirubinemia. Accumulating evidence also shows that genetic polymorphisms linked to hyperbilirubinemia are beneficial against various diseases. In this review article, we first introduce the production, metabolism, and transport of bilirubin. We then discuss the potential benefits of neonatal and adult hyperbilirubinemia. Finally, epigenetic factors as well as metabolomic information associated with hyperbilirubinemia are described. This review article advances the understanding of the physiological importance of the paradoxical compound bilirubin. (Hepatology 2018;67:1609-1619).

Authors: Ryoichi Fujiwara, Mathias Haag, Elke Schaeffeler, Anne T. Nies, Ulrich M. Zanger, Matthias Schwab

Date Published: 1st Apr 2018

Publication Type: Not specified

Abstract

Not specified

Authors: Daniel Moyo, Lynette Beattie, Paul S. Andrews, John W. J. Moore, Jon Timmis, Amy Sawtell, Stefan Hoehme, Adam T. Sampson, Paul M. Kaye

Date Published: 27th Mar 2018

Publication Type: Journal

Abstract (Expand)

OBJECTIVES: Variants in patatin-like phospholipase domain-containing 3 (PNPLA3; rs738409), transmembrane 6 superfamily member 2 (TM6SF2; rs58542926), and membrane bound O-acyltransferase domain containing 7 (MBOAT7; rs641738) are risk factors for the development of alcohol-related cirrhosis. Within this population, PNPLA3 rs738409 is also an established risk factor for the development of hepatocellular carcinoma (HCC). The aim of this study was to explore possible risk associations of TM6SF2 rs58542926 and MBOAT7 rs641738 with HCC. METHODS: Risk variants in PNPLA3, TM6SF2, and MBOAT7 were genotyped in 751 cases with alcohol-related cirrhosis and HCC and in 1165 controls with alcohol-related cirrhosis without HCC. Association with the risk of developing HCC was analyzed using multivariate logistic regression. RESULTS: The development of HCC was independently associated with PNPLA3 rs738409 (ORadjusted 1.84 [95% CI 1.55-2.18], p = 1.85 x 10(-12)) and TM6SF2 rs58542926 (ORadjusted 1.66 [1.30-2.13], p = 5.13 x 10(-05)), using an additive model, and controlling the sex, age, body mass index, and type 2 diabetes mellitus; the risk associated with carriage of MBOAT7 rs641738 (ORadjusted 1.04 [0.88-1.24], p = 0.61) was not significant. The population-attributable fractions were 43.5% for PNPLA3 rs738409, 11.5% for TM6SF2 rs58542926, and 49.9% for the carriage of both the variants combined. CONCLUSIONS: Carriage of TM6SF2 rs58542926 is an additional risk factor for the development of HCC in people with alcohol-related cirrhosis. Carriage of both PNPLA3 rs738409 and TM6SF2 rs58542926 accounts for half of the attributable risk for HCC in this population. Genotyping will allow for more precise HCC risk-stratification of patients with alcohol-related cirrhosis, and genotype-guided screening algorithms would optimize patient care.

Authors: F. Stickel, S. Buch, H. D. Nischalke, K. H. Weiss, D. Gotthardt, J. Fischer, J. Rosendahl, A. Marot, M. Elamly, M. Casper, F. Lammert, A. McQuillin, S. Zopf, U. Spengler, S. Marhenke, M. M. Kirstein, A. Vogel, F. Eyer, J. von Felden, H. Wege, T. Buch, C. Schafmayer, F. Braun, P. Deltenre, T. Berg, M. Y. Morgan, J. Hampe

Date Published: 15th Mar 2018

Publication Type: Journal

Abstract (Expand)

New technologies to generate, store and retrieve medical and research data are inducing a rapid change in clinical and translational research and health care. Systems medicine is the interdisciplinary approach wherein physicians and clinical investigators team up with experts from biology, biostatistics, informatics, mathematics and computational modeling to develop methods to use new and stored data to the benefit of the patient. We here provide a critical assessment of the opportunities and challenges arising out of systems approaches in medicine and from this provide a definition of what systems medicine entails. Based on our analysis of current developments in medicine and healthcare and associated research needs, we emphasize the role of systems medicine as a multilevel and multidisciplinary methodological framework for informed data acquisition and interdisciplinary data analysis to extract previously inaccessible knowledge for the benefit of patients.

Authors: R. Apweiler, T. Beissbarth, M. R. Berthold, N. Bluthgen, Y. Burmeister, O. Dammann, A. Deutsch, F. Feuerhake, A. Franke, J. Hasenauer, S. Hoffmann, T. Hofer, P. L. Jansen, L. Kaderali, U. Klingmuller, I. Koch, O. Kohlbacher, L. Kuepfer, F. Lammert, D. Maier, N. Pfeifer, N. Radde, M. Rehm, I. Roeder, J. Saez-Rodriguez, U. Sax, B. Schmeck, A. Schuppert, B. Seilheimer, F. J. Theis, J. Vera, O. Wolkenhauer

Date Published: 3rd Mar 2018

Publication Type: Not specified

Abstract (Expand)

Background: The extent of resection and the frequency of liver surgery have increased over the past decades, enabled by improved haemostasis provided by electrosurgical liver dissection. Because extensive liver surgery is still associated with lethal complications, further optimisation of the technique and a better molecular understanding of hepatic wound healing and regeneration are needed. Systematic studies and a mouse model reflecting the clinical reality of liver surgery are lacking. Methods: We performed liver resection in mice with a monopolar electrocautery device in comparison to the classical en-bloc ligation method. Regeneration was assessed using liver weight and BrDU immunohistochemistry after sacrifice and non-invasively using micro computed tomography (µCT). Results: Mortality in the electrosurgical model was similar to the ligation method given an identical extent of resection. Regeneration of liver proceeded significantly faster in the electrosurgical group: Liver weight was 25.6% higher at sacrifice after 168h (p=0.0003). Concordantly, both µCT analysis (22.6% higher liver volume at 168h, p=0.008) and BrDU staining (71.4% higher proliferation at 72h, p=0.0005) indicated superior regeneration of liver after electrosurgical partial hepatectomy. Conclusions: The mode of liver resection has a profound impact on regeneration and should be studied molecularly using the presented novel model of electrosurgical liver resection.

Authors: W. von Schonfels, Clemens Schafmayer, Jochen Hampe

Date Published: 27th Jan 2018

Publication Type: Not specified

Abstract (Expand)

Transient hepatic steatosis upon liver resection supposes functional relationships between lipid metabolism and liver regeneration. Repin1 has been suggested as candidate gene for obesity and dyslipidemia by regulating key genes of lipid metabolism and lipid storage. Herein, we characterized the regenerative potential of mice with a hepatic deletion of Repin1 (LRep1-/-) after partial hepatectomy (PH) in order to determine the functional significance of Repin1 in liver regeneration. Lipid dynamics and the regenerative response were analyzed at various time points after PH. Hepatic Repin1 deficiency causes a significantly decreased transient hepatic lipid accumulation. Defects in lipid uptake, as analyzed by decreased expression of the fatty acid transporter Cd36 and Fatp5, may contribute to attenuated and shifted lipid accumulation, accompanied by altered extent and chronological sequence of liver cell proliferation in LRep1-/- mice. In vitro steatosis experiments with primary hepatocytes also revealed attenuated lipid accumulation and occurrence of smaller lipid droplets in Repin1-deficient cells, while no direct effect on proliferation in HepG2 cells was observed. Based on these results, we propose that hepatocellular Repin1 might be of functional significance for early accumulation of lipids in hepatocytes after PH, facilitating efficient progression of liver regeneration.

Authors: K. Abshagen, B. Degenhardt, M. Liebig, A. Wendt, B. Genz, U. Schaeper, M. Stumvoll, U. Hofmann, M. Frank, B. Vollmar, N. Kloting

Date Published: 18th Jan 2018

Publication Type: Not specified

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