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Donath H, Wölke S, Knop V, Heß U, Duecker RP, Trischler J, Poynard T, Schubert R, Zielen S. Liver Assessment in Patients with Ataxia-Telangiectasia: Transient Elastography Detects Early Stages of Steatosis and Fibrosis. Can J Gastroenterol Hepatol 2023; 2023:2877350. [PMID: 36941982 PMCID: PMC10024628 DOI: 10.1155/2023/2877350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 01/12/2023] [Accepted: 01/31/2023] [Indexed: 03/13/2023] Open
Abstract
Background Ataxia-telangiectasia (A-T) is a rare autosomal-recessive multisystem disorder characterized by pronounced cerebellar ataxia, telangiectasia, cancer predisposition, and altered body composition. Liver diseases with steatosis, fibrosis, and hepatocellular carcinoma are frequent findings in older patients but sensitive noninvasive diagnostic tools are lacking. Objectives To determine the sensitivity of transient elastography (TE) as a screening tool for early hepatic tissue changes and serum biomarkers for liver disease. Methods Thirty-one A-T patients aged 2 to 25 years were examined prospectively from 2016-2018 by TE. In addition, we evaluated the diagnostic performance of liver biomarkers for steatosis and necroinflammatory activity (SteatoTest and ActiTest, Biopredictive, Paris) compared to TE. For calculation and comparison, patients were divided into two groups (<12, >12 years of age). Results TE revealed steatosis in 2/21 (10%) younger patients compared to 9/10 (90%) older patients. Fibrosis was present in 3/10 (30%) older patients as assessed by TE. We found a significant correlation of steatosis with SteatoTest, alpha-fetoprotein (AFP), HbA1c, and triglycerides. Liver stiffness correlated significantly with SteatoTest, ActiTest, HbA1c, and triglycerides. Conclusion Liver disease is a common finding in older A-T patients. TE is an objective measure to detect early stages of steatosis and fibrosis. SteatoTest and ActiTest are a good diagnostic assessment for steatosis and necroinflammatory activity in patients with A-T and confirmed the TE results.
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Affiliation(s)
- H. Donath
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - S. Wölke
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - V. Knop
- 2Department of Internal Medicine 1, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - U. Heß
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - R. P. Duecker
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - J. Trischler
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - T. Poynard
- 3Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Hepatology Department, Frankfurt, Germany
| | - R. Schubert
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - S. Zielen
- 1Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
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Rothmeier E, Pfaffinger G, Hoffmann C, Harrison CF, Grabmayr H, Repnik U, Hannemann M, Wölke S, Bausch A, Griffiths G, Müller-Taubenberger A, Itzen A, Hilbi H. Activation of Ran GTPase by a Legionella effector promotes microtubule polymerization, pathogen vacuole motility and infection. PLoS Pathog 2013; 9:e1003598. [PMID: 24068924 PMCID: PMC3777869 DOI: 10.1371/journal.ppat.1003598] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/22/2013] [Indexed: 11/19/2022] Open
Abstract
The causative agent of Legionnaires' disease, Legionella pneumophila, uses the Icm/Dot type IV secretion system (T4SS) to form in phagocytes a distinct "Legionella-containing vacuole" (LCV), which intercepts endosomal and secretory vesicle trafficking. Proteomics revealed the presence of the small GTPase Ran and its effector RanBP1 on purified LCVs. Here we validate that Ran and RanBP1 localize to LCVs and promote intracellular growth of L. pneumophila. Moreover, the L. pneumophila protein LegG1, which contains putative RCC1 Ran guanine nucleotide exchange factor (GEF) domains, accumulates on LCVs in an Icm/Dot-dependent manner. L. pneumophila wild-type bacteria, but not strains lacking LegG1 or a functional Icm/Dot T4SS, activate Ran on LCVs, while purified LegG1 produces active Ran(GTP) in cell lysates. L. pneumophila lacking legG1 is compromised for intracellular growth in macrophages and amoebae, yet is as cytotoxic as the wild-type strain. A downstream effect of LegG1 is to stabilize microtubules, as revealed by conventional and stimulated emission depletion (STED) fluorescence microscopy, subcellular fractionation and Western blot, or by microbial microinjection through the T3SS of a Yersinia strain lacking endogenous effectors. Real-time fluorescence imaging indicates that LCVs harboring wild-type L. pneumophila rapidly move along microtubules, while LCVs harboring ΔlegG1 mutant bacteria are stalled. Together, our results demonstrate that Ran activation and RanBP1 promote LCV formation, and the Icm/Dot substrate LegG1 functions as a bacterial Ran activator, which localizes to LCVs and promotes microtubule stabilization, LCV motility as well as intracellular replication of L. pneumophila.
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Affiliation(s)
- Eva Rothmeier
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Gudrun Pfaffinger
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Christine Hoffmann
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Christopher F. Harrison
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Heinrich Grabmayr
- Institute of Molecular and Cellular Biophysics, Department of Physics, Technische Universität München, Garching, Germany
| | - Urska Repnik
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Mandy Hannemann
- Center for Integrated Protein Science Munich, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Stefan Wölke
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Andreas Bausch
- Institute of Molecular and Cellular Biophysics, Department of Physics, Technische Universität München, Garching, Germany
| | - Gareth Griffiths
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | - Annette Müller-Taubenberger
- Institute for Anatomy and Cell Biology, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
| | - Aymelt Itzen
- Center for Integrated Protein Science Munich, Department of Chemistry, Technische Universität München, Garching, Germany
| | - Hubert Hilbi
- Max von Pettenkofer-Institute, Department of Medicine, Ludwig-Maximilians Universität München, München, Germany
- * E-mail:
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Abstract
The type 3 secretion system (T3SS) is a powerful bacterial nanomachine that is able to modify the host cellular immune defense in favor of the pathogen by injection of effector proteins. In this regard, cellular Rho GTPases such as Rac1, RhoA or Cdc42 are targeted by a large group of T3SS effectors by mimicking cellular guanine exchange factors or GTPase-activating proteins. However, functional analysis of one type of T3SS effector that is translocated by bacterial pathogens is challenging because the T3SS effector repertoire can comprise a large number of proteins with redundant or interfering functions. Therefore, we developed the Yersinia toolbox to either analyze singular effector proteins of Yersinia spp. or different bacterial species in the context of bacterial T3SS injection into cells. Here, we focus on the WxxxE guanine exchange factor mimetic proteins IpgB1, IpgB2 and Map, which activate Rac1, RhoA or Cdc42, respectively, as well as the Rho GTPase inactivators YopE (a GTPase-activating mimetic protein) and YopT (cysteine protease), to generate a toolbox module for Rho GTPase manipulation.
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Affiliation(s)
- Stefan Wölke
- Max von Pettenkofer Institut für Hygiene und Medizinische Mikrobiologie, LMU Munich, Pettenkofer Strasse 9A, 80336 Munich, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer Institut für Hygiene und Medizinische Mikrobiologie, LMU Munich, Pettenkofer Strasse 9A, 80336 Munich, Germany
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Wölke S, Ackermann N, Heesemann J. The Yersinia enterocolitica type 3 secretion system (T3SS) as toolbox for studying the cell biological effects of bacterial Rho GTPase modulating T3SS effector proteins. Cell Microbiol 2011; 13:1339-57. [PMID: 21718421 DOI: 10.1111/j.1462-5822.2011.01623.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The bacterial effector proteins IpgB(1) and IpgB(2) of Shigella and Map of Escherichia coli activate the Rho GTPases Rac1, RhoA and Cdc42, respectively, whereas YopE and YopT of Yersinia inhibit these Rho family GTPases. We established a Yersinia toolbox which allows to study the cellular effects of these effectors in different combinations in the context of Yersinia type 3 secretion system (Ysc)-T3SS-mediated injection into HeLa cells. For this purpose hybrid proteins were constructed by fusion of YopE with the effector protein of interest. As expected, injected hybrid proteins induced membrane ruffles and Yersinia uptake for IpgB(1) , stress fibres for IpgB(2) and microspikes for Map. By co-infection experiments we could demonstrate (i) IpgB(2) -mediated and ROCK-dependent inhibition of IpgB(1) -mediated Rac1 effects, (ii) YopT-mediated suppression of IpgB(1) -induced Yersinia invasion and (iii) failure of YopE-mediated suppression of IpgB(1) -induced Yersinia invasion, presumably due to preferential inhibition of RhoG by YopE GAP function. By infecting polarized MDCK cells we could demonstrate that Map or IpgB(1) but not IpgB(2) affects cell monolayer integrity. In summary, the Yersinia toolbox is suitable to study cellular effects of effector proteins of diverse bacterial species separately or in combination in the context of bacterial T3SS-mediated injection.
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Affiliation(s)
- Stefan Wölke
- Max von Pettenkofer Institut, LMU Munich, Pettenkofer Straße 9A, 80336 Munich, Germany
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