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Ehlting C, Trilling M, Tiedje C, Le-Trilling VTK, Albrecht U, Kluge S, Zimmermann A, Graf D, Gaestel M, Hengel H, Häussinger D, Bode JG. MAPKAP kinase 2 regulates IL-10 expression and prevents formation of intrahepatic myeloid cell aggregates during cytomegalovirus infections. J Hepatol 2016; 64:380-389. [PMID: 26299622 DOI: 10.1016/j.jhep.2015.08.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/19/2015] [Accepted: 08/11/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS The kinase p38(MAPK) and its downstream target MAPKAP kinase (MK) 2 are critical regulators of inflammatory responses towards pathogens. To date, the relevance of MK2 for regulating IL-10 expression and other cytokine responses towards cytomegalovirus (CMV) infection and the impact of this pathway on viral replication in vitro and in vivo is unknown and the subject of this study. METHODS The effect of MK2, interferon-α receptor (IFNAR)1, tristetraprolin (TTP) and IL-10 on mouse (M)CMV virus titres, cytokine expression, signal transduction, transcript stability, liver enzymes release, immune cell recruitment and aggregation in response to MCMV infection were studied ex vivo in hepatocytes and macrophages, as well as in vivo. RESULTS MK2 is critical for MCMV-induced production of IL-10, IFN-α2 and 4, IFN-β, IL-6, and TNF-α but not for IFN-γ. The MCMV-induced IL-10 production requires activation of IFNAR1 and is further regulated by MK2 and TTP-dependent stabilization of IL-10 transcripts. MK2(-/-) mice are able to control acute MCMV replication, despite deregulated cytokine production. This may be related to the observation that MCMV-infected MK2(-/-) mice show enhanced formation of focal intrahepatic lymphocyte infiltrates resembling intrahepatic myeloid cell aggregates of T cell expansion (iMATEs), which were also observed in MCMV-infected IL-10(-/-) mice but are almost absent in MCMV-infected wild-type controls. CONCLUSIONS The data suggest that MK2 is critical for regulating cytokine responses towards acute MCMV infection, including that of IL-10 via IFNARI-mediated circuits. MCMV stimulates expression of MK2-dependent cytokines, in particular IL-10 and thereby prevents enhanced formation of intrahepatic iMATE-like cellular aggregates.
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Affiliation(s)
- Christian Ehlting
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany
| | - Mirko Trilling
- Institute for Virology, University Hospital, University Duisburg-Essen, Germany; Institute for Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Germany
| | - Christopher Tiedje
- Institute of Physiological Chemistry, Hannover Medical School, Hannover, Germany
| | - Vu Thuy Khanh Le-Trilling
- Institute for Virology, University Hospital, University Duisburg-Essen, Germany; Institute for Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Germany
| | - Ute Albrecht
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany
| | - Stefanie Kluge
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany
| | - Albert Zimmermann
- Institute for Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Germany
| | - Dirk Graf
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany
| | - Matthias Gaestel
- Institute of Physiological Chemistry, Hannover Medical School, Hannover, Germany
| | - Hartmut Hengel
- Institute of Virology, University Medical Center, Albert-Ludwigs-University of Freiburg, Germany
| | - Dieter Häussinger
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany
| | - Johannes Georg Bode
- Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Medical Faculty, Heinrich-Heine-University of Düsseldorf, Germany.
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Kluge S, Domanova O, Berlage T, Häussinger D, Kubitz R. Role of primary bile salts in the regulation of sinusoidal substrate uptake in rat liver. Eur J Med Res 2014. [PMCID: PMC4118440 DOI: 10.1186/2047-783x-19-s1-s23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Ulrich H, Bocsi J, Glaser T, Tárnok A. Cytometry in the brain: studying differentiation to diagnostic applications in brain disease and regeneration therapy. Cell Prolif 2014; 47:12-9. [PMID: 24450810 DOI: 10.1111/cpr.12087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/02/2013] [Indexed: 12/30/2022] Open
Abstract
During brain development, a population of uniform embryonic cells migrates and differentiates into a large number of neural phenotypes - origin of the enormous complexity of the adult nervous system. Processes of cell proliferation, differentiation and programmed death of no longer required cells, do not occur only during embryogenesis, but are also maintained during adulthood and are affected in neurodegenerative and neuropsychiatric disease states. As neurogenesis is an endogenous response to brain injury, visible as proliferation (of to this moment silent stem or progenitor cells), its further stimulation can present a treatment strategy in addition to stem cell transfer for cell regeneration therapy. Concise techniques for studying such events in vitro and in vivo permit understanding of underlying mechanisms. Detection of subtle physiological alterations in brain cell proliferation and neurogenesis can be explored, that occur during environmental stimulation, exercise and ageing. Here, we have collected achievements in the field of basic research on applications of cytometry, including automated imaging for quantification of morphological or fluorescence-based parameters in cell cultures, towards imaging of three-dimensional brain architecture together with DNA content and proliferation data. Multi-parameter and more recently in vivo flow cytometry procedures, have been developed for quantification of phenotypic diversity and cell processes that occur during brain development as well as in adulthood, with importance for therapeutic approaches.
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Affiliation(s)
- H Ulrich
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, São Paulo, S.P 05508-900, Brazil
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Mühlfeld S, Domanova O, Berlage T, Stross C, Helmer A, Keitel V, Häussinger D, Kubitz R. Short-term feedback regulation of bile salt uptake by bile salts in rodent liver. Hepatology 2012; 56:2387-97. [PMID: 22806967 DOI: 10.1002/hep.25955] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 06/18/2012] [Indexed: 12/17/2022]
Abstract
UNLABELLED The sodium taurocholate cotransporting polypeptide (Ntcp) is the major bile salt uptake transporter at the sinusoidal membrane of hepatocytes. Short-term feedback regulation of Ntcp by primary bile salts has not yet been investigated in vivo. Subcellular localization of Ntcp was analyzed in Ntcp-transfected HepG2-cells by flow cytometry and in immunofluorescence images from tissue sections by a new automated image analysis method. Net bile salt uptake was investigated in perfused rat liver by a pulse chase technique. In Flag-Ntcp-EGFP (enhanced green fluorescent protein) expressing HepG2-cells, taurochenodeoxycholate (TCDC), but not taurocholate (TC), induced endocytosis of Ntcp. TCDC, but not TC, caused significant internalization of Ntcp in perfused rat livers, as shown by an increase in intracellular Ntcp immunoreactivity, whereas Bsep distribution remained unchanged. These results correlate with functional studies. Rat livers were continuously perfused with 100 μmol/L of TC. 25 μmol/L of TCDC, taurodeoxycholate (TDC), tauroursodeoxycholate (TUDC), or TC were added for 30 minutes, washed out, followed by a pulse of (3) [H]-TC. TCDC, but not TDC, TUDC, or TC significantly increased the amount of (3) [H]-TC in the effluent, indicating a reduced sinusoidal net TC uptake. This effect was sensitive to chelerythrine (protein kinase C inhibitor) and cypermethrin (protein phosphatase 2B inhibitor). Phosphoinositide 3-kinase (PI3K) inhibitors had an additive effect, whereas Erk1/2 (extracellular signal activated kinase 1/2), p38MAPK, protein phosphatase 1/2A (PP1/2A), and reactive oxygen species (ROS) were not involved. CONCLUSION TCDC regulates bile salt transport at the sinusoidal membrane by protein kinase C- and protein phosphatase 2B-mediated retrieval of Ntcp from the plasma membrane. During increased portal bile salt load this mechanism may adjust bile salt uptake along the acinus and protect periportal hepatocytes from harmful bile salt concentrations.
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Affiliation(s)
- Stefanie Mühlfeld
- Department of Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
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