1
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Strigli A, Gopalakrishnan S, Zeissig Y, Basic M, Wang J, Schwerd T, Doms S, Peuker K, Hartwig J, Harder J, Hönscheid P, Arnold P, Kurth T, Rost F, Petersen BS, Forster M, Franke A, Kelsen JR, Rohlfs M, Klein C, Muise AM, Warner N, Nambu R, Mayerle J, Török HP, Linkermann A, Muders MH, Baretton GB, Hampe J, Aust DE, Baines JF, Bleich A, Zeissig S. Deficiency in X-linked inhibitor of apoptosis protein promotes susceptibility to microbial triggers of intestinal inflammation. Sci Immunol 2021. [PMID: 34739342 DOI: 10.1126/sciimmunol.abf7473/suppl_file/sciimmunol.abf7473_tables_s2_and_s4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Inflammatory bowel disease (IBD) is characterized by inappropriate immune responses to the microbiota in genetically susceptible hosts, but little is known about the pathways that link individual genetic alterations to microbiota-dependent inflammation. Here, we demonstrated that the loss of X-linked inhibitor of apoptosis protein (XIAP), a gene associated with Mendelian IBD, rendered Paneth cells sensitive to microbiota-, tumor necrosis factor (TNF)–, receptor-interacting protein kinase 1 (RIPK1)–, and RIPK3-dependent cell death. This was associated with deficiency in Paneth cell–derived antimicrobial peptides and alterations in the stratification and composition of the microbiota. Loss of XIAP was not sufficient to elicit intestinal inflammation but provided susceptibility to pathobionts able to promote granulomatous ileitis, which could be prevented by administration of a Paneth cell–derived antimicrobial peptide. These data reveal a pathway critical for host-microbial cross-talk, which is required for intestinal homeostasis and the prevention of inflammation and which is amenable to therapeutic targeting.
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Affiliation(s)
- Anne Strigli
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Shreya Gopalakrishnan
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Yvonne Zeissig
- Department of General Pediatrics, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Marijana Basic
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Jun Wang
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany.,CAS Key Laboratory for Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tobias Schwerd
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Shauni Doms
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany
| | - Kenneth Peuker
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jelka Hartwig
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jürgen Harder
- Department of Dermatology, University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Pia Hönscheid
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Philipp Arnold
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Thomas Kurth
- Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Fabian Rost
- Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Center for Information Services and High Performance Computing (ZIH), Technische Universität (TU) Dresden, 01602 Dresden, Germany
| | | | - Michael Forster
- Institute for Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
| | - Andre Franke
- Institute for Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
| | - Judith R Kelsen
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Meino Rohlfs
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Christoph Klein
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Aleixo M Muise
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Pediatrics, Institute of Medical Science and Biochemistry, University of Toronto, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Neil Warner
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Ryusuke Nambu
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Division of Gastroenterology and Hepatology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Julia Mayerle
- Department of Medicine II, University Hospital, LMU Munich, 80337 Munich, Germany
| | - Helga-Paula Török
- Department of Medicine II, University Hospital, LMU Munich, 80337 Munich, Germany
| | - Andreas Linkermann
- Division of Nephrology, Department of Medicine III, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Michael H Muders
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Gustavo B Baretton
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jochen Hampe
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Daniela E Aust
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Tumor and Normal Tissue Bank of the University Cancer Center (UCC), University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - John F Baines
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany
| | - André Bleich
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Sebastian Zeissig
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
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2
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Strigli A, Gopalakrishnan S, Zeissig Y, Basic M, Wang J, Schwerd T, Doms S, Peuker K, Hartwig J, Harder J, Hönscheid P, Arnold P, Kurth T, Rost F, Petersen BS, Forster M, Franke A, Kelsen JR, Rohlfs M, Klein C, Muise AM, Warner N, Nambu R, Mayerle J, Török HP, Linkermann A, Muders MH, Baretton GB, Hampe J, Aust DE, Baines JF, Bleich A, Zeissig S. Deficiency in X-linked inhibitor of apoptosis protein promotes susceptibility to microbial triggers of intestinal inflammation. Sci Immunol 2021; 6:eabf7473. [PMID: 34739342 DOI: 10.1126/sciimmunol.abf7473] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inflammatory bowel disease (IBD) is characterized by inappropriate immune responses to the microbiota in genetically susceptible hosts, but little is known about the pathways that link individual genetic alterations to microbiota-dependent inflammation. Here, we demonstrated that the loss of X-linked inhibitor of apoptosis protein (XIAP), a gene associated with Mendelian IBD, rendered Paneth cells sensitive to microbiota-, tumor necrosis factor (TNF)–, receptor-interacting protein kinase 1 (RIPK1)–, and RIPK3-dependent cell death. This was associated with deficiency in Paneth cell–derived antimicrobial peptides and alterations in the stratification and composition of the microbiota. Loss of XIAP was not sufficient to elicit intestinal inflammation but provided susceptibility to pathobionts able to promote granulomatous ileitis, which could be prevented by administration of a Paneth cell–derived antimicrobial peptide. These data reveal a pathway critical for host-microbial cross-talk, which is required for intestinal homeostasis and the prevention of inflammation and which is amenable to therapeutic targeting.
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Affiliation(s)
- Anne Strigli
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Shreya Gopalakrishnan
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Yvonne Zeissig
- Department of General Pediatrics, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Marijana Basic
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Jun Wang
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany.,CAS Key Laboratory for Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Tobias Schwerd
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Shauni Doms
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany
| | - Kenneth Peuker
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jelka Hartwig
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jürgen Harder
- Department of Dermatology, University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Pia Hönscheid
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Philipp Arnold
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Thomas Kurth
- Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Fabian Rost
- Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Center for Information Services and High Performance Computing (ZIH), Technische Universität (TU) Dresden, 01602 Dresden, Germany
| | | | - Michael Forster
- Institute for Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
| | - Andre Franke
- Institute for Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany
| | - Judith R Kelsen
- Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Meino Rohlfs
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Christoph Klein
- Department of Pediatrics, Dr von Hauner Children's Hospital, LMU Munich, 80337 Munich, Germany
| | - Aleixo M Muise
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Cell Biology Program, Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Department of Pediatrics, Institute of Medical Science and Biochemistry, University of Toronto, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Neil Warner
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Ryusuke Nambu
- SickKids Inflammatory Bowel Disease Center, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.,Division of Gastroenterology and Hepatology, Saitama Children's Medical Center, Saitama 330-8777, Japan
| | - Julia Mayerle
- Department of Medicine II, University Hospital, LMU Munich, 80337 Munich, Germany
| | - Helga-Paula Török
- Department of Medicine II, University Hospital, LMU Munich, 80337 Munich, Germany
| | - Andreas Linkermann
- Division of Nephrology, Department of Medicine III, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Michael H Muders
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Gustavo B Baretton
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Jochen Hampe
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - Daniela E Aust
- Institute of Pathology, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Tumor and Normal Tissue Bank of the University Cancer Center (UCC), University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
| | - John F Baines
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.,Institute for Experimental Medicine, Kiel University, 24105 Kiel, Germany
| | - André Bleich
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Sebastian Zeissig
- Center for Regenerative Therapies, Technische Universität (TU) Dresden, 01307 Dresden, Germany.,Department of Medicine I, University Medical Center Dresden, Technische Universität (TU) Dresden, 01307 Dresden, Germany
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3
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Hartwig J, Loebel M, Steiner S, Bauer S, Karadeniz Z, Roeger C, Skurk C, Scheibenbogen C, Sotzny F. Metformin Attenuates ROS via FOXO3 Activation in Immune Cells. Front Immunol 2021; 12:581799. [PMID: 33953705 PMCID: PMC8089390 DOI: 10.3389/fimmu.2021.581799] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 03/31/2021] [Indexed: 12/16/2022] Open
Abstract
Forkhead box O 3 (FOXO3) is a transcription factor involved in cell metabolism, inflammation and longevity. Here, we investigated if metformin can activate FOXO3 in human immune cells and affects the subsequent level of reactive oxygen/nitrogen species (ROS/RNS) in immune cells. AMP-activated protein kinase (AMPK) and FOXO3 activation were investigated by immunoblot or flow cytometry (FC) analysis, respectively. FOXO3 target gene expression was quantified by real-time PCR. ROS/RNS measurement using dichlorodihydrofluorescein diacetate (DCFH-DA) dye was investigated by FC. The role of the FOXO3 single nucleotide polymorphisms (SNPs) rs12212067, rs2802292 and rs12206094 on ROS/RNS production was studied using allelic discrimination PCR. Metformin induced activation of AMPK (pT172) and FOXO3 (pS413). ROS/RNS level was reduced in immune cells after metformin stimulation accompanied by induction of the FOXO3 targets mitochondrial superoxide dismutase and cytochrome c. Studies in Foxo3 deficient (Foxo3-/- ) mouse splenocytes confirmed that metformin mediates its effects via Foxo3 as it attenuates ROS/RNS in myeloid cells of wildtype (WT) but not of Foxo3-/- mice. Our results suggest that FOXO3 can be activated by metformin leading to reduced ROS/RNS level in immune cells. This may add to the beneficial clinical effects of metformin observed in large cohort studies on longevity, cardiovascular and cancer risk.
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Affiliation(s)
- Jelka Hartwig
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Madlen Loebel
- Science Center, Carl-Thiem-Klinikum Cottbus, Cottbus, Germany
| | - Sophie Steiner
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Sandra Bauer
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Zehra Karadeniz
- Department of Cardiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Roeger
- Department of Cardiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Skurk
- Department of Cardiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research) Partner Site Berlin, Berlin, Germany
| | - Carmen Scheibenbogen
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
| | - Franziska Sotzny
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
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4
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Szklarski M, Freitag H, Lorenz S, Becker SC, Sotzny F, Bauer S, Hartwig J, Heidecke H, Wittke K, Kedor C, Hanitsch LG, Grabowski P, Sepúlveda N, Scheibenbogen C. Delineating the Association Between Soluble CD26 and Autoantibodies Against G-Protein Coupled Receptors, Immunological and Cardiovascular Parameters Identifies Distinct Patterns in Post-Infectious vs. Non-Infection-Triggered Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Immunol 2021; 12:644548. [PMID: 33889154 PMCID: PMC8056217 DOI: 10.3389/fimmu.2021.644548] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/17/2021] [Indexed: 12/15/2022] Open
Abstract
Soluble cluster of differentiation 26 (sCD26) has a wide range of enzymatic functions affecting immunological, metabolic and vascular regulation. Diminished sCD26 concentrations have been reported in various autoimmune diseases and also in Myalgic Encephalomyelitis/Chronic fatigue syndrome (ME/CFS). Here we re-evaluate sCD26 as a diagnostic marker and perform a comprehensive correlation analysis of sCD26 concentrations with clinical and paraclinical parameters in ME/CFS patients. Though this study did find significantly lower concentrations of sCD26 only in the female cohort and could not confirm diagnostic suitability, results from correlation analyses provide striking pathomechanistic insights. In patients with infection-triggered onset, the associations of low sCD26 with elevated autoantibodies (AAB) against alpha1 adrenergic (AR) and M3 muscarinic acetylcholine receptors (mAChR) point to a pathomechanism of infection-triggered autoimmune-mediated vascular and immunological dysregulation. sCD26 concentrations in infection-triggered ME/CFS were found to be associated with activated T cells, liver enzymes, creatin kinase (CK) and lactate dehydrogenase (LDH) and inversely with Interleukin-1 beta (IL-1b). Most associations are in line with the known effects of sCD26/DPP-4 inhibition. Remarkably, in non-infection-triggered ME/CFS lower sCD26 in patients with higher heart rate after orthostatic challenge and postural orthostatic tachycardia syndrome (POTS) suggest an association with orthostatic regulation. These findings provide evidence that the key enzyme sCD26 is linked to immunological alterations in infection-triggered ME/CFS and delineate a different pathomechanism in the non-infectious ME/CFS subset.
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Affiliation(s)
- Marvin Szklarski
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Helma Freitag
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sebastian Lorenz
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sonya C. Becker
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Franziska Sotzny
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sandra Bauer
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jelka Hartwig
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | | | - Kirsten Wittke
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Claudia Kedor
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Leif G. Hanitsch
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Patricia Grabowski
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Nuno Sepúlveda
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Carmen Scheibenbogen
- Institute of Medical Immunology, Charité –Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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5
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Hartwig J, Kretschmer-Trendowicz A, Helmert JR, Jung ML, Pannasch S. Revealing the dynamics of prospective memory processes in children with eye movements. Int J Psychophysiol 2021; 160:38-55. [PMID: 33387575 DOI: 10.1016/j.ijpsycho.2020.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/16/2022]
Abstract
Prospective memory (PM), the memory for delayed intentions, develops during childhood. The current study examined PM processes, such as monitoring, PM cue identification and intention retrieval with particular focus on their temporal dynamics and interrelations during successful and unsuccessful PM performance. We analysed eye movements of 6-7 and 9-10 year olds during the inspection of movie stills while they completed one of three different tasks: scene viewing followed by a snippet allocation task, a PM task and a visual search task. We also tested children's executive functions of inhibition, flexibility and working memory. We found that older children outperformed younger children in all tasks but neither age group showed variations in monitoring behaviour during the course of the PM task. In fact, neither age group monitored. According to our data, initial processes necessary for PM success take place during the first fixation on the PM cue. In PM hit trials we found prolonged fixations after the first fixation on the PM cue, and older children showed a greater efficiency in PM processes following this first PM cue fixation. Regarding executive functions, only working memory had a significant effect on children's PM performance. Across both age groups children with better working memory scores needed less time to react to the PM cue. Our data support the notion that children rely on spontaneous processes to notice the PM cue, followed by a resource intensive search for the intended action.
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Affiliation(s)
- J Hartwig
- Chair of Engineering Psychology and Applied Cognitive Research, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany.
| | - A Kretschmer-Trendowicz
- Chair of Lifespan Developmental Neuroscience, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany
| | - J R Helmert
- Chair of Engineering Psychology and Applied Cognitive Research, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany
| | - M L Jung
- Chair of Engineering Psychology and Applied Cognitive Research, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany
| | - S Pannasch
- Chair of Engineering Psychology and Applied Cognitive Research, Technische Universität Dresden, Zellescher Weg 17, 01062 Dresden, Germany
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6
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Karadeniz Z, Winter J, Smeir E, Hartwig J, Na E, Kraenkel N, Kurreck J, Scheibenbogen C, Landmesser U, Skurk C. Novel effects of Foxo3a on immune system and cardiac remodeling after myocardial infarction. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.3643] [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] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Fibroblast/myofibroblast transdifferentiation following acute cardiac injury (MI) is a major mechanism of scar formation and adverse remodeling regulated by TGFβ/SMAD3 signaling. Myofibroblasts represent phenotypically modulated cells characterized by α-smooth muscle actin (α-SMA) and constitute the main source of extracellular matrix proteins such as collagen type I in the healing infarct wound. Moreover, the recruitment of a specific monocyte/macrophages subset (Ly6Chigh and Ly6Clow) control the healing process in the infarcted wound. The forkhead transcription factor FOXO3a has recently been shown to inhibit cardiac hypertrophy by different stressors and is involved in the immune response following injury.
Purpose
We hypothesized that FOXO3a, a key regulator of cell differentiation, cell cycle and size as well as the stress response, might inhibit matricellular remodeling following myocardial infarction by regulating transdifferentiation of fibroblasts into myofibroblasts. Moreover, we hypothesized that Foxo3a−/− mice favor the recruitment of monocytes of the type Ly6Clow leading to an anti-inflammatory profile and thus the remodeling after injury.
Methods
Acute myocardial infarction was induced in FOXO3−/− and WT mice (FVB background) by permanent LAD ligation. The myocardial infarction size was determined via ECHO. Myofibroblast trans-differentiation and fibrosis markers were analyzed by QT-PCR and protein analysis. The differentiation of macrophages studied via FACS. IP/IF and Western blotting were used to test for a direct interaction between FOXO3a and SMAD3 in vitro.
Results
FOXO3a−/− mice showed significantly higher survival rates compared to WT littermates. Myocardial inflammation (Mac-1, LFA, CD3, CD45), injury markers such as Troponin T were similar in both groups on day 4 post-MI. Myocardial expression of alpha smooth muscle actin (ASMA) and Collagen1A1 (Col1A1), as well as numbers of cardiac CD11b+/F4–80+/Ly6clow macrophages was significantly enhanced in FOXO3a−/− mice 15 days post infarction. Moreover, Foxo3a−/− mice showed larger fibrotic areas following MI. Mechanistically, immunoprecipitation showed direct interaction of FOXO3a with SMAD3a that was enhanced following activation of the transcription factor leading to diminished SMAD3 downstream gene expression.
Conclusion
Our results indicate that FOXO3a acts as a direct inhibitor of TGF-β regulated myofibroblast differentiation and matrix remodeling via FOXO3a-SMAD3 interaction following MI. Moreover, a Foxo3a deficiency might lead to the recruitment of monocytes type Ly6Clow leading to an anti-inflammatory profile in the infarct wound. Therefore, FOXO3a collectively regulates cardiac hypertrophy and fibrosis/scar formation following MI. Thus, targeting the FOXO3a-SMAD3 signaling axis might be of future therapeutic interest.
Funding Acknowledgement
Type of funding source: Foundation. Main funding source(s): German Resaerch Foundation
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Affiliation(s)
- Z Karadeniz
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - J Winter
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - E Smeir
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - J Hartwig
- Berlin-Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - E Na
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - N Kraenkel
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - J Kurreck
- Technische Universitaet Berlin, Berlin, Germany
| | - C Scheibenbogen
- Berlin-Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - U Landmesser
- Charite - Campus Benjamin Franklin, Berlin, Germany
| | - C Skurk
- Charite - Campus Benjamin Franklin, Berlin, Germany
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7
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Tölle M, Freitag H, Antelmann M, Hartwig J, Schuchardt M, van der Giet M, Eckardt KU, Grabowski P, Scheibenbogen C. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Efficacy of Repeat Immunoadsorption. J Clin Med 2020; 9:E2443. [PMID: 32751659 PMCID: PMC7465279 DOI: 10.3390/jcm9082443] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 07/28/2020] [Indexed: 12/23/2022] Open
Abstract
(1) Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex neuroimmunological disease. There is evidence for an autoimmune mechanism for ME/CFS with an infection-triggered onset and dysfunction of ß2-adrenoreceptor antibodies (ß2AR-AB). In a first proof-of-concept study, we could show that IA was effective to reduce ß2AR-AB and led to improvement of various symptoms. (2) Five of the ME/CFS patients who had clinical improvement following treatment with a five-day IA were retreated in the current study about two years later with a modified IA protocol. The severity of symptoms was assessed by disease specific scores during a follow-up period of 12 months. The antibodies were determined by ELISA. (3) The modified IA treatment protocol resulted in a remarkable similar clinical response. The treatment was well tolerated and 80-90% decline of total IgG and ß2AR-AB was achieved. Four patients showed a rapid improvement in several clinical symptoms during IA therapy, lasting for six to 12 months. One patient had no improvement. (4) We could provide further evidence that IA has clinical efficacy in patients with ME/CFS. Data from our pilot trial warrant further controlled studies in ME/CFS.
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Affiliation(s)
- Markus Tölle
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 12203 Berlin, Germany; (M.T.); (M.S.); (M.v.d.G.); (K.-U.E.)
| | - Helma Freitag
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (H.F.); (M.A.); (J.H.); (P.G.)
| | - Michaela Antelmann
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (H.F.); (M.A.); (J.H.); (P.G.)
| | - Jelka Hartwig
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (H.F.); (M.A.); (J.H.); (P.G.)
| | - Mirjam Schuchardt
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 12203 Berlin, Germany; (M.T.); (M.S.); (M.v.d.G.); (K.-U.E.)
| | - Markus van der Giet
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 12203 Berlin, Germany; (M.T.); (M.S.); (M.v.d.G.); (K.-U.E.)
| | - Kai-Uwe Eckardt
- Department of Nephrology and Medical Intensive Care, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 12203 Berlin, Germany; (M.T.); (M.S.); (M.v.d.G.); (K.-U.E.)
| | - Patricia Grabowski
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (H.F.); (M.A.); (J.H.); (P.G.)
| | - Carmen Scheibenbogen
- Institute of Medical Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt Universität zu Berlin, and Berlin Institute of Health, 13353 Berlin, Germany; (H.F.); (M.A.); (J.H.); (P.G.)
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), 13353 Berlin, Germany
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8
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Steiner S, Becker SC, Hartwig J, Sotzny F, Lorenz S, Bauer S, Löbel M, Stittrich AB, Grabowski P, Scheibenbogen C. Autoimmunity-Related Risk Variants in PTPN22 and CTLA4 Are Associated With ME/CFS With Infectious Onset. Front Immunol 2020; 11:578. [PMID: 32328064 PMCID: PMC7161310 DOI: 10.3389/fimmu.2020.00578] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
Single nucleotide polymorphisms (SNP) in various genes have been described to be associated with susceptibility to autoimmune disease. In this study, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients and controls were genotyped for five immune gene SNPs in tyrosine phosphatase non-receptor type 22 (PTPN22, rs2476601), cytotoxic T-lymphocyte-associated protein 4 (CTLA4, rs3087243), tumor necrosis factor (TNF, rs1800629 and rs1799724), and interferon regulatory factor 5 (IRF5, rs3807306), which are among the most important risk variants for autoimmune diseases. Analysis of 305 ME/CFS patients and 201 healthy controls showed significant associations of the PTPN22 rs2476601 and CTLA4 rs3087243 autoimmunity-risk alleles with ME/CFS. The associations were only found in ME/CFS patients, who reported an acute onset of disease with an infection (PTPN22 rs2476601: OR 1.63, CI 1.04–2.55, p = 0.016; CTLA4 rs3087243: OR 1.53, CI 1.17–2.03, p = 0.001), but not in ME/CFS patients without infection-triggered onset (PTPN22 rs2476601: OR 1.09, CI 0.56–2.14, p = 0.398; CTLA4 rs3087243: OR 0.89, CI 0.61–1.30, p = 0.268). This finding provides evidence that autoimmunity might play a role in ME/CFS with an infection-triggered onset. Both genes play a key role in regulating B and T cell activation.
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Affiliation(s)
- Sophie Steiner
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Sonya C Becker
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Jelka Hartwig
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Franziska Sotzny
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Sebastian Lorenz
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Sandra Bauer
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Madlen Löbel
- Carl-Thiem-Klinikum Cottbus gGmbH, Research Center, Cottbus, Germany
| | - Anna B Stittrich
- BIH Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Labor Berlin-Charité Vivantes GmbH, Berlin, Germany
| | - Patricia Grabowski
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany
| | - Carmen Scheibenbogen
- Institute of Medical Immunology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität (FU) Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health (BIH), Berlin, Germany.,BIH Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Berlin, Germany
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9
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Scherbakov N, Szklarski M, Hartwig J, Sotzny F, Lorenz S, Meyer A, Grabowski P, Doehner W, Scheibenbogen C. Peripheral endothelial dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome. ESC Heart Fail 2020; 7:1064-1071. [PMID: 32154656 PMCID: PMC7261521 DOI: 10.1002/ehf2.12633] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/23/2019] [Accepted: 01/14/2020] [Indexed: 12/11/2022] Open
Abstract
AIMS Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystem disease. Evidence for disturbed vascular regulation comes from various studies showing cerebral hypoperfusion and orthostatic intolerance. The peripheral endothelial dysfunction (ED) has not been sufficiently investigated in patients with ME/CFS. The aim of the present study was to examine peripheral endothelial function in patients with ME/CFS. METHODS AND RESULTS Thirty-five patients [median age 40 (range 18-70) years, mean body mass index 23.8 ± 4.2 kg/m2 , 31% male] with ME/CFS were studied for peripheral endothelial function assessed by peripheral arterial tonometry (EndoPAT2000). Clinical diagnosis of ME/CFS was based on Canadian Criteria. Nine of these patients with elevated antibodies against β2-adrenergic receptor underwent immunoadsorption, and endothelial function was measured at baseline and 3, 6, and 12 months follow-up. ED was defined by reactive hyperaemia index ≤1.81. Twenty healthy subjects of similar age and body mass index were used as a control group. Peripheral ED was found in 18 of 35 patients (51%) with ME/CFS and in 4 healthy subjects (20%, P < 0.05). Patients with ED, in contrast to patients with normal endothelial function, reported more severe disease according to Bell score (31 ± 12 vs. 40 ± 16, P = 0.04), as well as more severe fatigue-related symptoms (8.62 ± 0.87 vs. 7.75 ± 1.40, P = 0.04) including a higher demand for breaks [9.0 (interquartile range 7.0-10.0) vs. 7.5 (interquartile range 6.0-9.25), P = 0.04]. Peripheral ED showed correlations with more severe immune-associated symptoms (r = -0.41, P = 0.026), such as sore throat (r = -0.38, P = 0.038) and painful lymph nodes (r = -0.37, P = 0.042), as well as more severe disease according to Bell score (r = 0.41, P = 0.008) and symptom score (r = -0.59, P = 0.005). There were no differences between the patient group with ED and the patient group with normal endothelial function regarding demographic, metabolic, and laboratory parameters. Further, there was no difference in soluble vascular cell adhesion molecule and soluble intercellular adhesion molecule levels. At baseline, peripheral ED was observed in six patients who underwent immunoadsorption. After 12 months, endothelial function had improved in five of these six patients (reactive hyperaemia index 1.58 ± 0.15 vs. 2.02 ± 0.46, P = 0.06). CONCLUSIONS Peripheral ED is frequent in patients with ME/CFS and associated with disease severity and severity of immune symptoms. As ED is a risk factor for cardiovascular disease, it is important to elucidate if peripheral ED is associated with increased cardiovascular morbidity and mortality in ME/CFS.
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Affiliation(s)
- Nadja Scherbakov
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Augustenburger Platz 1, 13353, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany.,Department of Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Marvin Szklarski
- Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jelka Hartwig
- Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Franziska Sotzny
- Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Lorenz
- Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Antje Meyer
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Augustenburger Platz 1, 13353, Berlin, Germany.,Department of Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Patricia Grabowski
- Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Wolfram Doehner
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Augustenburger Platz 1, 13353, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany.,Department of Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Carmen Scheibenbogen
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Augustenburger Platz 1, 13353, Berlin, Germany.,Institute of Medical Immunology, Campus Virchow, Charité - Universitätsmedizin Berlin, Berlin, Germany
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10
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Schuurmans M, Hartwig J, Hamp P, Murer C, Robinson C, Mueller N, Benden C. P152 Diagnostic discrepancies between rapid and standard polymerase chain reaction laboratory tests for influenza virus detection in nasopharyngeal swabs from symptomatic lung transplant recipients. Chest 2017. [DOI: 10.1016/j.chest.2017.04.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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11
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Zeissig Y, Petersen BS, Milutinovic S, Bosse E, Mayr G, Peuker K, Hartwig J, Keller A, Kohl M, Laass MW, Billmann-Born S, Brandau H, Feller AC, Röcken C, Schrappe M, Rosenstiel P, Reed JC, Schreiber S, Franke A, Zeissig S. XIAP variants in male Crohn's disease. Gut 2015; 64:66-76. [PMID: 24572142 DOI: 10.1136/gutjnl-2013-306520] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The genetic basis of inflammatory bowel disease (IBD) is incompletely understood. The aim of this study was to identify rare genetic variants involved in the pathogenesis of IBD. DESIGN Exome sequencing and immunological profiling were performed in a patient with early onset Crohn's disease (CD). The coding region of the gene encoding X-linked inhibitor of apoptosis protein (XIAP) was sequenced in samples of 275 paediatric IBD and 1047 adult-onset CD patients. XIAP genotyping was performed in samples of 2680 IBD patients and 2864 healthy controls. Functional effects of the variants identified were investigated in primary cells and cultured cell lines. RESULTS Our results demonstrate the frequent occurrence of private variants in XIAP in about four percent of male patients with paediatric-onset CD. While XIAP mutations are known to be associated with the primary immunodeficiency (PID) X-linked lymphoproliferative disease type 2 (XLP2), CD patients described here exhibited intestinal inflammation in the absence of XLP2 and harboured a spectrum of mutations partially distinct from that observed in XLP2. The majority of XIAP variants identified was associated with a selective defect in NOD1/2 signalling, impaired NOD1/2-mediated activation of NF-κB, and altered NF-κB-dependent cytokine production. CONCLUSIONS This study reveals the unanticipated, frequent occurrence of XIAP variants in male paediatric-onset CD. The link between XIAP and NOD1/2, and the association of XIAP variants with XLP2, support the concept of PID in a subset of IBD patients. Moreover, these studies provide a rationale for the implementation of XIAP sequencing in clinical diagnostics in male patients with severe CD.
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Affiliation(s)
- Yvonne Zeissig
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany Department of General Pediatrics, University Medical Center Schleswig-Holstein, Kiel, Germany Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Britt-Sabina Petersen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | | | - Esther Bosse
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Gabriele Mayr
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Kenneth Peuker
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Jelka Hartwig
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Andreas Keller
- Clinical Bioinformatics, Saarland University, Saarbrücken, Germany
| | - Martina Kohl
- Department of General Pediatrics, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Martin W Laass
- Children's Hospital, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Germany
| | - Susanne Billmann-Born
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Heide Brandau
- Department of General Pediatrics, University Medical Center Schleswig-Holstein, Lübeck, Germany
| | - Alfred C Feller
- Institute of Pathology, University Medical Center Schleswig-Holstein, Lübeck, Germany
| | - Christoph Röcken
- Institute of Pathology, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Martin Schrappe
- Department of General Pediatrics, University Medical Center Schleswig-Holstein, Kiel, Germany
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - John C Reed
- Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Stefan Schreiber
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Sebastian Zeissig
- Department of Internal Medicine I, University Medical Center Schleswig-Holstein, Kiel, Germany
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12
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Klatte-Schulz F, Pauly S, Scheibel M, Greiner S, Gerhardt C, Hartwig J, Schmidmaier G, Wildemann B. Characteristics and stimulation potential with BMP-2 and BMP-7 of tenocyte-like cells isolated from the rotator cuff of female donors. PLoS One 2013; 8:e67209. [PMID: 23825642 PMCID: PMC3692432 DOI: 10.1371/journal.pone.0067209] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [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: 10/16/2012] [Accepted: 05/17/2013] [Indexed: 01/08/2023] Open
Abstract
Tendon bone healing of the rotator cuff is often associated with non-healing or recurrent defects, which seems to be influenced by the patient’s age and sex. The present study aims to examine cellular biological characteristics of tenocyte-like cells that may contribute to this impaired rotator cuff healing. Moreover, a therapeutic approach using growth factors could possibly stimulate tendon bone healing. Therefore, our second aim was to identify patient groups who would particularly benefit from growth factor stimulation. Tenocyte-like cells isolated from supraspinatus tendons of female donors younger and older than 65 years of age were characterized with respect to different cellular biological parameters, such as cell density, cell count, marker expression, collagen-I protein synthesis, and stem cell potential. Furthermore, cells of the donor groups were stimulated with BMP-2 and BMP-7 (200 and 1000 ng/ml) in 3D-culture and analyzed for cell count, marker expression and collagen-I protein synthesis. Female donors older than 65 years of age showed significantly decreased cell count and collagen-I protein synthesis compared to cells from donors younger than 65 years. Cellular biological parameters including cell count, collagen-I and –III expression, and collagen-I protein synthesis of cells from both donor groups were stimulated with BMP-2 and BMP-7. The cells from donors older than 65 years revealed a decreased stimulation potential for cell count compared to the younger group. Cells from female donors older than 65 years of age showed inferior cellular biological characteristics. This may be one reason for a weaker healing potential observed in older female patients and should be taken into consideration for tendon bone healing of the rotator cuff.
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Affiliation(s)
- Franka Klatte-Schulz
- Julius Wolff Institute, Center for Musculoskeletal Surgery, Charité-Universitaetsmedizin Berlin, Berlin, Germany.
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13
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Affiliation(s)
- S. Riem
- Zentrum für Alterstraumatologie DIN EN ISO 9001:2008, Klinik für Orthopädie und Unfallchirurgie, Diakonissenkrankenhaus Karlsruhe
| | - E. Hartwig
- Zentrum für Alterstraumatologie DIN EN ISO 9001:2008, Klinik für Orthopädie und Unfallchirurgie, Diakonissenkrankenhaus Karlsruhe
| | - J. Hartwig
- Fraunhofer-Institut für System- und Innovationsforschung ISI, Karlsruhe
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14
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Schmahlfeldt G, Mündelein N, Hartwig J, Krause L, Deppe-Schwittay W, Zaramba C. Erfolgreiche Zusammenarbeit zum Wohle der Kinder: Ernährungskurs in der offenen Ganztagsschule Veermoor in Hamburg-Lurup. Gesundheitswesen 2011. [DOI: 10.1055/s-0031-1300928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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Hartwig J, Waller H. Stufen und Hürden der Teilnahme an Krebsvorsorgeuntersuchungen bei 45 - 60-jährigen Männern - Ergebnisse einer empirischen Untersuchung. Gesundheitswesen 2006; 68:357-63. [PMID: 16826468 DOI: 10.1055/s-2006-926878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
UNLABELLED Between 2002 and 2004 the Centre of Applied Health Sciences of the University of Lüneburg carried out a research project concerning the cancer screening behaviour of men. Within a standardised survey all men aged 45 - 60 years of a local health insurance company were interviewed by a postal questionnaire about their cancer screening behaviour including their main reasons to engage or not to engage in the (insurance financed) cancer screening tests. 337 questionnaires could be analysed. As a theoretical framework, the "transtheoretical model" of Prochaska et al. was used to characterise the men according to their degree of readiness to engage in cancer screening tests. RESULTS 25% of the men were regularly engaged in cancer screening tests. 40% have been engaged at least once or were in the stage of "preparation" to do so in the near future. 35% were resistant to undergo cancer screening tests. Anxiety concerning the check-up itself or the possibility to have a positive result were the main barriers for men not to engage in cancer screening. As an important factor to overcome such barriers, these men mentioned the need for better communication between doctors and patients. To improve cancer screening behaviour, this was considered more important than general information campaigns or organisational changes concerning the check-ups.
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Affiliation(s)
- J Hartwig
- Zentrum für Angewandte Gesundheitswissenschaften, Lüneburg.
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16
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Gardel ML, Nakamura F, Hartwig J, Crocker JC, Stossel TP, Weitz DA. Stress-dependent elasticity of composite actin networks as a model for cell behavior. Phys Rev Lett 2006; 96:088102. [PMID: 16606229 DOI: 10.1103/physrevlett.96.088102] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Indexed: 05/08/2023]
Abstract
Networks of filamentous actin cross-linked with the actin-binding protein filamin A exhibit remarkable strain stiffening leading to an increase in differential elastic modulus by several orders of magnitude over the linear value. The variation of the frequency dependence of the differential elastic and loss moduli as a function of prestress is consistent with that observed in living cells, suggesting that cell elasticity is always measured in the nonlinear regime, and that prestress is an essential control parameter.
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Affiliation(s)
- M L Gardel
- Department of Physics and D.E.A.S., Harvard University, Cambridge, Massachusetts 02138, USA
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Abstract
From 1999 to 2001 the "Centre of Applied Health Sciences" (University of Luneburg) carried out a research project in cooperation with the Psychiatric Hospital Hacklingen in Luneburg and the department of social psychiatry and psychotherapy of the Hanover College of Medicine. The project covered the prevalence of mental disorders among the residents of nursing and geriatric homes in the district of Uelzen including different aspects of medical, psychiatric and nursing care. The research was based on a survey including all residents of these institutions. The response rate was 925 of a total of 1,100 residents. Results showed that three-quarters of the residents had considerable and different psychiatric symptoms and that almost half of the residents suffered from symptoms of dementia. The provision of health care as well as nursing care for these residents are considerably deficient. Care facilities are hardly of therapeutical standard and guidelines. This refers in particular to treatment with psychoactive drugs. The (few) comparable studies show that -- with the exception of some pilot projects -- the situation in the district of Uelzen may be similar to that in other regions of Germany.
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Affiliation(s)
- J Hartwig
- Zentrum für angewandte Gesundheitswissenschaften, Universität Lüneburg.
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Stojanoff V, Cappelle B, Epelboin Y, Hartwig J, Moradela AB, Otalora F. High Resolution Imaging as a Characterization Tool for Biological Crystals. Ann N Y Acad Sci 2004; 1027:48-55. [PMID: 15644344 DOI: 10.1196/annals.1324.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Biomolecular crystals consist of large unit cells that form a rather flexible medium that is able to accommodate a certain degree of lattice distortion, leading to several interesting issues ranging from structural to physical properties. Several techniques, from X-ray diffraction to microscopy, have been adapted to study the structural and physical properties of biomolecular crystals systematically. The use of synchrotron-based monochromatic X-ray diffraction topography, with triple axis diffractometry and rocking curve measurements, to characterize biomolecular crystals is reviewed. Recent X-ray diffraction images from gel and solution grown lysozyme crystals are presented. Defect structures in these crystals are discussed, together with reciprocal space mapping, and compared with results obtained from crystals grown in a low gravity environment.
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Affiliation(s)
- Vivian Stojanoff
- National Synchrotron Light Source, Brookhaven National Laboratories, Upton, NY 11973, USA.
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Gerard J, Chapet O, Romestaing P, Baulieux J, Hartwig J, Nemoz C. Improved sphincter preservation of low rectal cancer with high dose preoperative radiotherapy: the lyon R96-02 randomized trial. Int J Radiat Oncol Biol Phys 2003. [DOI: 10.1016/s0360-3016(03)00971-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Platelets are small subcellular fragments that are formed from the cytoplasm of bone marrow megakaryocytes, which circulate in blood with characteristic discoid shapes. To assemble and release platelets, megakaryocytes follow a maturation program that accumulates in the conversion of the bulk of their cytoplasmic into multiple long processes called proplatelets. A megakaryocyte may protrude as many as 10-20 proplatelets, each which begins as a blunt protrusion that is driven out by microtubule-based forces. With time, these protrusions thin and branch repeatedly. Platelets form only at the ends of proplatelets. As the nascent platelet matures, its content of granules and organelles are delivered as a stream of individual particles moving from the megakaryocyte cell body to the proplatelet tip. Once the platelet has been filled with its content of intracellular materials, a single microtubule approximately 100 micro m in length is rolled into a coil, and the platelet releases into the medium. Platelet formation can be divided into two phases. In the first phase, there is nuclear proliferation to 16-32xN and the enlargement of the megakaryocyte cytoplasm as it is filled with cytoskeletal proteins, platelet specific granules and granule contents and membranous systems. This phase occurs over a period of days and requires induction by megakaryocyte specific growth factors. Proplatelets are extended in the second phase and platelets are released. This phase is completed in hours.
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Affiliation(s)
- J Hartwig
- Hematology Division, Brigham & Women's Hospital, Boston, MA 02115, USA.
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Bak-Misiuk J, Shalimov A, Kaniewski J, Misiuk A, Dynowska E, Reginski K, Trela J, Przesławski T, Hartwig J. Stress-induced structural changes in thin InAs layers grown on GaAs substrate. Cryst Res Technol 2003. [DOI: 10.1002/crat.200310035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Baruchel J, Agliozzo S, Gastaldi J, Hartwig J, Klein H, Mancini L. Defects in quasicrystals investigated by coherent beam X-ray imaging. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302091869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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Hartwig J. Transfusion medicine illustrated. The human blood platelet, resting and active. Transfusion 2001; 41:723. [PMID: 11399808 DOI: 10.1046/j.1537-2995.2001.41060723.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- J Hartwig
- Hematology Division, Brigham & Women's Hospital, Boston, Massachusetts 02115-5822, USA.
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Glogauer M, Hartwig J, Stossel T. Two pathways through Cdc42 couple the N-formyl receptor to actin nucleation in permeabilized human neutrophils. J Cell Biol 2000; 150:785-96. [PMID: 10953003 PMCID: PMC2175292 DOI: 10.1083/jcb.150.4.785] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2000] [Accepted: 06/23/2000] [Indexed: 12/03/2022] Open
Abstract
We developed a permeabilization method that retains coupling between N-formyl-methionyl-leucyl-phenylalanine tripeptide (FMLP) receptor stimulation, shape changes, and barbed-end actin nucleation in human neutrophils. Using GTP analogues, phosphoinositides, a phosphoinositide-binding peptide, constitutively active or inactive Rho GTPase mutants, and activating or inhibitory peptides derived from neural Wiskott-Aldrich syndrome family proteins (N-WASP), we identified signaling pathways leading from the FMLP receptor to actin nucleation that require Cdc42, but then diverge. One branch traverses the actin nucleation pathway involving N-WASP and the Arp2/3 complex, whereas the other operates through active Rac to promote actin nucleation. Both pathways depend on phosphoinositide expression. Since maximal inhibition of the Arp2/3 pathway leaves an N17Rac inhibitable alternate pathway intact, we conclude that this alternate involves phosphoinositide-mediated uncapping of actin filament barbed ends.
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Affiliation(s)
- M Glogauer
- Hematology Division, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Sobocka MB, Sobocki T, Banerjee P, Weiss C, Rushbrook JI, Norin AJ, Hartwig J, Salifu MO, Markell MS, Babinska A, Ehrlich YH, Kornecki E. Cloning of the human platelet F11 receptor: a cell adhesion molecule member of the immunoglobulin superfamily involved in platelet aggregation. Blood 2000; 95:2600-9. [PMID: 10753840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
This study demonstrates that the human platelet F11 receptor (F11R) functions as an adhesion molecule, and this finding is confirmed by the structure of the protein as revealed by molecular cloning. The F11R is a 32-/35-kd protein duplex that serves as the binding site through which a stimulatory monoclonal antibody causes platelet aggregation and granule secretion. A physiological role for the F11R protein was demonstrated by its phosphorylation after the stimulation of platelets by thrombin and collagen. A pathophysiological role for the F11R was revealed by demonstrating the presence of F11R-antibodies in patients with thrombocytopenia. Adhesion of platelets through the F11R resulted in events characteristic of the action of cell adhesion molecules (CAMs). To determine the structure of this protein, we cloned the F11R cDNA from human platelets. The predicted amino acid sequence demonstrated that it is an integral membrane protein and an immunoglobulin superfamily member containing 2 extracellular C2-type domains. The structure of the F11R as a member of a CAM family of proteins and its activity in mediating adhesion confirm each another. We conclude that the F11R is a platelet-membrane protein involved in 2 distinct processes initiated on the platelet surface. The first is antibody-induced platelet aggregation and secretion that are dependent on both the FcgammaRII and the GPIIb/IIIa integrin and that may be involved in pathophysiological processes associated with certain thrombocytopenias. The second is an F11R-mediated platelet adhesion that is not dependent on either the FcgammaRII or the fibrinogen receptor and that appears to play a role in physiological processes associated with platelet adhesion and aggregation. (Blood. 2000;95:2600-2609)
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Affiliation(s)
- M B Sobocka
- Department of Anatomy/Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA
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Abstract
We have found that a complex consisting of a type I PIPK and a DGK associates with the GTPase Rac1. Binding of the lipid kinase complex is through the C-terminus of Rac. Complex formation is augmented in the presence of specific phospholipids. The complex also associates with Rho GDI, through Rac. Based on the role of PtdIns-4,5-P2 in regulating proteins that influence actin structures we propose that the Rac-associated lipid kinase complex functions to generate locally high concentrations of PtdIns-4,5-P2 in a Rac-dependent manner. There are many possible roles PtdIns-4,5-P2 might play. A likely role is binding to barbed-end actin capping proteins. This would release the capping protein, providing free barbed ends for actin polymerization. Uncapping would occur at the membrane so that additional actin polymerization would result in membrane protrusions and lamellapodia, in a Brownian ratchet model. It is also possible that PtdIns-4,5-P2 has other roles, such as promoting the release of G actin from profilin or promoting the cross-linking of actin or its anchorage to the plasma membrane. Studies are currently underway to determine the role of this lipid kinase complex in Rac signaling and actin regulation in vivo.
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Howard TH, Hartwig J, Cunningham C. Lymphocyte-specific protein 1 expression in eukaryotic cells reproduces the morphologic and motile abnormality of NAD 47/89 neutrophils. Blood 1998; 91:4786-95. [PMID: 9616178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite its name, the actin-binding protein lymphocyte-specific protein1 (LSP1) is found in all hematopoetic cells, and yet its role in cell function remains unclear. Recently, LSP1 was identified as the 47-kD protein overexpressed in the polymorphonuclear neutrophils of patients with a rare neutrophil disorder, neutrophil actin dysfunction with abnormalities of 47-kD and 89-kD proteins (NAD 47/89). These neutrophils are immotile, defective in actin polymerization in response to agonists, and display distinctive, fine, "hairlike" F-actin-rich projections on their cell surfaces. We now show that overexpression of LSP1 produces F-actin bundles that are likely responsible for the morphologic and motile abnormalities characteristic of the NAD 47/89 phenotype. Coincident with LSP1 overexpression, cells from each of several different eukaryotic lines, including a highly motile human melanoma line, develop hairlike surface projections that branch distinctively and contain F-actin and LSP1. The hairlike projections are supported at their core by thick actin bundles, composed of actin filaments of mixed polarity, which periodically anastomose to generate a branching structure. The motility of the melanoma cells is inhibited even at low levels of LSP1 expression. Therefore, these studies show that overexpression of LSP1 alone can recreate the morphologic and motile defects seen in NAD 47/89 and suggest that LSP1 is distinct from other known actin binding proteins in its effect on F-actin network structure.
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Affiliation(s)
- T H Howard
- Department of Pediatrics and Cell Biology, University of Alabama at Birmingham, School of Medicine, Birmingham, AL 35233, USA
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Marti A, Luo Z, Cunningham C, Ohta Y, Hartwig J, Stossel TP, Kyriakis JM, Avruch J. Actin-binding protein-280 binds the stress-activated protein kinase (SAPK) activator SEK-1 and is required for tumor necrosis factor-alpha activation of SAPK in melanoma cells. J Biol Chem 1997; 272:2620-8. [PMID: 9006895 DOI: 10.1074/jbc.272.5.2620] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
SEK-1, a dual specificity protein kinase that serves as one of the immediate upstream activators of the stress-activated protein kinases (SAPKs), associates specifically with the actin-binding protein, ABP-280, in vitro and in situ. SEK-1 binds to the carboxyl-terminal rod segment of ABP-280, upstream of the ABP carboxyl-terminal dimerization domain. Activation of SEK-1 in situ increases the SEK-1 activity bound to ABP-280 without changing the amount of SEK-1 polypeptide bound. The influence of ABP-280 on SAPK regulation was evaluated in human melanoma cells that lack ABP-280 expression, and in stable transformants of these cells expressing wild type ABP, or an actin-binding but dimerization-deficient mutant ABP (ABPDeltaCT109). ABP-280-deficient cells show an activation of SAPK in response to most stimuli that is comparable to that seen in ABP-280-replete cells; ABP-280-deficient cells, however, fail to show the brisk tumor necrosis factor-alpha (TNF-alpha) activation of SAPK seen in ABP-replete cells and have an 80% reduction in SAPK activation by lysophosphatidic acid. Expression of the dimerization-deficient mutant ABP-280 fails to correct the defective SAPK response to lysophosphatidic acid, but essentially normalizes the TNF-alpha activation of SAPK. Thus, a lack of ABP-280 in melanoma cells causes a defect in the regulation of SAPK that is selective for TNF-alpha and is attributable to the lack of ABP-280 polypeptide itself rather than to the disordered actin cytoskeleton that results therefrom. ABP-280 participates in TNF-alpha signal transduction to SAPKs, in part through the binding of SEK-1.
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Affiliation(s)
- A Marti
- Diabetes Unit and Medical Services, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 021291, USA
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Leterrier JF, Käs J, Hartwig J, Vegners R, Janmey PA. Mechanical effects of neurofilament cross-bridges. Modulation by phosphorylation, lipids, and interactions with F-actin. J Biol Chem 1996; 271:15687-94. [PMID: 8663092 DOI: 10.1074/jbc.271.26.15687] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The structure of gels formed by bovine spinal cord neurofilaments was determined by fluorescence and electron microscopy and compared to mechanical properties measured by their elastic and viscous response to shear forces. Neurofilaments formed gels of high elastic modulus (>100 Pa) after addition of millimolar Mg2+. Gelation caused a slow increase in shear moduli to levels similar to those of vimentin intermediate filament networks, followed by a rapid rise due to formation of links between neurofilaments, mediated by cross-bridging structures that vimentin filaments lack. Neurofilament gels are more resistant to large deformations than are vimentin networks, suggesting the importance of cross-bridges for neurofilament mechanical properties. Fluorescence imaging of single neurofilaments showed flexible filaments that became straighter when they adhered to glass or were incorporated into filament bundles. Electron microscopy of neurofilament gels showed a system of bundles intertwined within a more isotropic network of individual filaments. Neurofilament gel formation was stimulated in vitro by acid phosphatase treatment or by inositol phospholipids. In contrast, addition of actin filaments reduced the resistance of neurofilament gels to large stresses. These results suggest that dynamic and regulated interactions occur between neurofilaments to form viscoelastic networks with properties distinct from other cytoskeletal structures.
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Cox D, Wessels D, Soll DR, Hartwig J, Condeelis J. Re-expression of ABP-120 rescues cytoskeletal, motility, and phagocytosis defects of ABP-120- Dictyostelium mutants. Mol Biol Cell 1996; 7:803-23. [PMID: 8744952 PMCID: PMC275931 DOI: 10.1091/mbc.7.5.803] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The actin binding protein ABP-120 has been proposed to cross-link actin filaments in nascent pseudopods, in a step required for normal pseudopod extension in motile Dictyostelium amoebae. To test this hypothesis, cell lines that lack ABP-120 were created independently either by chemical mutagenesis or homologous recombination. Different phenotypes were reported in these two studies. The chemical mutant shows only a subtle defect in actin cross-linking, while the homologous recombinant mutants show profound defects in actin cross-linking, cytoskeletal structure, pseudopod number and size, cell motility and chemotaxis and, as shown here, phagocytosis. To resolve the controversy as to what the ABP-120- phenotype is, ABP-120 was re-expressed in an ABP-120- cell line created by homologous recombination. Two independently "rescued" cell lines that express wild-type levels of ABP-120 were analyzed. In both rescued cell lines, actin incorporation into the cytoskeleton, pseudopod formation, cell morphology, instantaneous velocity, phagocytosis, and chemotaxis were restored to wild-type levels. There is no alteration in the expression levels of several related actin binding proteins in either the original ABP-120- cell line or in the rescued cell lines, leading to the conclusion that neither the aberrant phenotype observed in ABP-120- cells nor the normal phenotype reasserted in rescued cells can be attributed to alterations in the levels of other abundant and related actin binding proteins. Re-expression of ABP-120 in ABP-120- cells reestablishes normal structural and behavioral parameters, demonstrating that the severity and properties of the structural and behavioral defects of ABP-120- cell lines produced by homologous recombination are the direct result of the absence of ABP-120.
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Affiliation(s)
- D Cox
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Cox D, Ridsdale JA, Condeelis J, Hartwig J. Genetic deletion of ABP-120 alters the three-dimensional organization of actin filaments in Dictyostelium pseudopods. J Cell Biol 1995; 128:819-35. [PMID: 7876307 PMCID: PMC2120398 DOI: 10.1083/jcb.128.5.819] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
This study extends the observations on the defects in pseudopod formation of ABP-120+ and ABP-120- cells by a detailed morphological and biochemical analysis of the actin based cytoskeleton. Both ABP-120+ and ABP-120- cells polymerize the same amount of F-actin in response to stimulation with cAMP. However, unlike ABP-120+ cells, ABP-120- cells do not incorporate actin into the Triton X-100-insoluble cytoskeleton at 30-50 s, the time when ABP-120 is incorporated into the cytoskeleton and when pseudopods are extended after cAMP stimulation in wild-type cells. By confocal and electron microscopy, pseudopods extended by ABP-120- cells are not as large or thick as those produced by ABP-120+ cells and in the electron microscope, an altered filament network is found in pseudopods of ABP-120- cells when compared to pseudopods of ABP-120+ cells. The actin filaments found in areas of pseudopods in ABP-120+ cells either before or after stimulation were long, straight, and arranged into space filling orthogonal networks. Protrusions of ABP-120- cells are less three-dimensional, denser, and filled with multiple foci of aggregated filaments consistent with collapse of the filament network due to the absence of ABP-120-mediated cross-linking activity. The different organization of actin filaments may account for the diminished size of protrusions observed in living and fixed ABP-120- cells compared to ABP-120+ cells and is consistent with the role of ABP-120 in regulating pseudopod extension through its cross-linking of actin filaments.
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Affiliation(s)
- D Cox
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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Holtz D, Tanaka RA, Hartwig J, McKeon F. The CaaX motif of lamin A functions in conjunction with the nuclear localization signal to target assembly to the nuclear envelope. Cell 1989; 59:969-77. [PMID: 2557160 DOI: 10.1016/0092-8674(89)90753-8] [Citation(s) in RCA: 186] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
While the nuclear lamin proteins (A, B, and C) assemble specifically at the surface of the nuclear membrane, their sequences do not reveal stretches of hydrophobic amino acids that might explain their association with the nuclear membranes. However, the A and B lamin proteins possess Ras-like C-terminal CaaX sequence motifs, which in Ras proteins are sites of hydrophobic modifications required for membrane association and function. From the analysis of single and double lamin A mutants affecting the CaaX motif, the nuclear localization signal, and higher-order assembly properties, we propose that the CaaX motif functions as a nonspecific, low affinity membrane probe for proteins ultimately segregated to specific cellular membrane systems. Committed association with specific membranes requires additional interactions with membrane-resident factors.
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Affiliation(s)
- D Holtz
- Department of Cellular and Molecular Physiology, Harvard Medical School, Boston, Massachusetts 02115
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Sixma JJ, van den Berg A, Jockusch BM, Hartwig J. Immunoelectron microscopic localization of actin, alpha-actinin, actin-binding protein and myosin in resting and activated human blood platelets. Eur J Cell Biol 1989; 48:271-81. [PMID: 2744001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Blood platelets are particularly rich in cytoskeletal proteins and respond to stimulation and activation by changes in shape. We examined the effect of blood platelet activation on the subcellular distribution of the cytoskeletal proteins, actin, myosin, alpha-actinin and actin-binding protein. These studies were performed with immunofluorescent staining on thin cryosections of paraformaldehyde-fixed platelets and by immunogold labeling of ultrathin cryosections of glutaraldehyde-fixed blood platelets. Platelets were studied immediately at blood collection (resting platelets), in platelet-rich plasma and after gel filtration (partially activated platelets), and after gel filtration and thrombin activation (0.5 U/ml, 10 min, 37 degrees C) (activated platelets). Resting platelets were disk-shaped and showed homogeneous distribution of cytoskeletal proteins. Partially activated platelets were more spherical and showed at least one protrusion. Immunofluorescence and immunogold labeling showed a more intense staining of the peripheral 0.2 to 0.3 micron of cytoplasm of these platelets. In the immunofluorescence photographs this resulted in the appearance of small fluorescent rings with staining at the periphery of cross-sectioned cells. Activated platelets showed an irregular outline composed of broad based pseudopods. Cell centers were composed of poorly delineated electron-dense material, interspersed with profiles of surface-connected tubules. The broad based pseudopods stained uniformely for actin, alpha-actinin and actin-binding protein. The cell center stained poorly for these proteins. Myosin staining was found in the peripheral cortex, but also in the cell center. Partially activated platelets that had returned to the disk shape after incubation at 37 degrees C showed increased submembranous concentration of microfilament proteins. These data reveal the profound cytoskeletal rearrangements that already occur upon minimal platelet activation and emphasize that platelets that have returned to the disk shape are not identical to resting platelets.
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Affiliation(s)
- J J Sixma
- Department of Hematology, State University of Utrecht/The Netherlands
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Brown D, Gluck S, Hartwig J. Structure of the novel membrane-coating material in proton-secreting epithelial cells and identification as an H+ATPase. J Biophys Biochem Cytol 1987; 105:1637-48. [PMID: 2889740 PMCID: PMC2114636 DOI: 10.1083/jcb.105.4.1637] [Citation(s) in RCA: 174] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Specialized proton-secreting cells known collectively as mitochondria-rich cells are found in a variety of transporting epithelia, including the kidney collecting duct (intercalated cells) and toad and turtle urinary bladders. These cells contain a population of characteristic tubulovesicles that are believed to be involved in the shuttling of proton pumps (H+ATPase) to and from the plasma membrane. These transporting vesicles have a dense, studlike material coating the cytoplasmic face of their limiting membranes and similar studs are also found beneath parts of the plasma membrane. We have recently shown that this membrane coat does not contain clathrin. The present study was performed to determine the structure of this coat in rapidly frozen and freeze-dried tissue, and to determine whether the coat contains a major membrane protein transported by these vesicles, a proton pumping H+ATPase. The structure of the coat was examined in proton-secreting, mitochondria-rich cells from toad urinary bladder epithelium by rapidly freezing portions of apical membrane and associated cytoplasm that were sheared away from the remainder of the cell using polylysine-coated coverslips. Regions of the underside of these apical membranes as large as 0.2 micron2 were decorated by studlike projections that were arranged into regular hexagonal arrays. Individual studs had a diameter of 9.5 nm and appeared to be composed of multiple subunits arranged around a central depression, possibly representing a channel. The studs had a density of approximately 16,800 per micron2 of membrane. Similar arrays of studs were also found on vesicles trapped in the residual band of cytoplasm that remained attached to the underside of the plasma membrane, but none were seen in adjacent granular cells. To determine whether these arrays of studs contained H+ATPase molecules, we examined a preparation of affinity-purified bovine medullary H+ATPase, using the same technique, after incorporation of the protein eluted from a monoclonal antibody affinity column into phospholipid liposomes. The affinity-purified protein was shown to be capable of ATP-dependent acidification. In such preparations, large paracrystalline arrays of studs identical in appearance to those seen in situ were found. The dimensions of the studs as well as the number per square micrometer of membrane were identical to those of toad bladder mitochondria-rich cells: 9.5 nm in diameter, 16,770 per micron2 of membrane.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- D Brown
- Renal Unit, Medical Services, Massachusetts General Hospital, Boston 02114
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Jack RM, Ezzell RM, Hartwig J, Fearon DT. Differential interaction of the C3b/C4b receptor and MHC class I with the cytoskeleton of human neutrophils. The Journal of Immunology 1986. [DOI: 10.4049/jimmunol.137.12.3996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
As measured by fluorescence microscopy and radioligand binding, C3b/C4b receptors (CR1) became attached to the detergent-insoluble cytoskeleton of human neutrophils when receptors were cross-linked by affinity-purified polyclonal F(ab')2 anti-CR1, dimeric C3b, or Fab monoclonal anti-CR1 followed by F(ab')2 goat anti-mouse F(ab')2. CR1 on neutrophils bearing monovalent anti-CR1 was not attached to the cytoskeleton. In contrast, cross-linked CR1 on erythrocytes and cross-linked MHC Class I on neutrophils were not cytoskeleton associated. A possible role for filamentous actin (F-actin) in the binding of cross-linked CR1 to neutrophil cytoskeleton was suggested by three observations. When neutrophils were differentially extracted with either Low Salt-detergent buffer or High Salt-detergent buffer, stained with FITC-phalloidin, and examined by fluorescent flow cytometry, the residual cytoskeletons generated with the former buffer were shown to contain polymerized F-actin, whereas cytoskeletons generated with the latter buffer were found to be depleted of F-actin. In parallel experiments, High Salt-detergent buffer was also found to release cross-linked CR1 from neutrophils. Second, depolymerization of F-actin by DNAse I released half of the cytoskeletal-associated cross-linked CR1. Third, immunoadsorbed neutrophil CR1, but not MHC Class I or erythrocyte CR1, specifically bound soluble 125I-actin. In addition, Fc receptor and CR3, other phagocytic membrane proteins of neutrophils, specifically bound 125I-actin. These data demonstrate that CR1 cross-linked on neutrophils becomes associated with detergent-insoluble cytoskeleton and that this interaction is mediated either directly or indirectly by actin.
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Jack RM, Ezzell RM, Hartwig J, Fearon DT. Differential interaction of the C3b/C4b receptor and MHC class I with the cytoskeleton of human neutrophils. J Immunol 1986; 137:3996-4003. [PMID: 2946771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
As measured by fluorescence microscopy and radioligand binding, C3b/C4b receptors (CR1) became attached to the detergent-insoluble cytoskeleton of human neutrophils when receptors were cross-linked by affinity-purified polyclonal F(ab')2 anti-CR1, dimeric C3b, or Fab monoclonal anti-CR1 followed by F(ab')2 goat anti-mouse F(ab')2. CR1 on neutrophils bearing monovalent anti-CR1 was not attached to the cytoskeleton. In contrast, cross-linked CR1 on erythrocytes and cross-linked MHC Class I on neutrophils were not cytoskeleton associated. A possible role for filamentous actin (F-actin) in the binding of cross-linked CR1 to neutrophil cytoskeleton was suggested by three observations. When neutrophils were differentially extracted with either Low Salt-detergent buffer or High Salt-detergent buffer, stained with FITC-phalloidin, and examined by fluorescent flow cytometry, the residual cytoskeletons generated with the former buffer were shown to contain polymerized F-actin, whereas cytoskeletons generated with the latter buffer were found to be depleted of F-actin. In parallel experiments, High Salt-detergent buffer was also found to release cross-linked CR1 from neutrophils. Second, depolymerization of F-actin by DNAse I released half of the cytoskeletal-associated cross-linked CR1. Third, immunoadsorbed neutrophil CR1, but not MHC Class I or erythrocyte CR1, specifically bound soluble 125I-actin. In addition, Fc receptor and CR3, other phagocytic membrane proteins of neutrophils, specifically bound 125I-actin. These data demonstrate that CR1 cross-linked on neutrophils becomes associated with detergent-insoluble cytoskeleton and that this interaction is mediated either directly or indirectly by actin.
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Abstract
Nine patients with hypertrophic cardiomyopathy associated with Friedreich's ataxia were treated with the calcium antagonist verapamil, which is known to reduce myocardial hypertrophy and improve diastolic function in patients with idiopathic hypertrophic cardiomyopathy. Daily oral doses of 7 mg/kg were given for a mean (SD) of 24 (8) months. M mode echocardiography performed at the start of the study and at the end of follow up showed no significant difference between the treated group and an untreated control group of nine patients. Verapamil produced no changes in left ventricular wall thickness, mass index, left ventricular internal diameter, fractional shortening, peak normalised lengthening rate, peak rate of septal and posterior wall thinning, and time from minimum ventricular cavity dimension to mitral valve opening. Myocardial calcium overload has been suggested as a cause of cardiac disease in Friedreich's ataxia; however, verapamil had no beneficial effect on these patients with established myocardial hypertrophy.
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Salvadeo A, Hartwig J, Perduca M, Villa G. [Cefonicid (SK&F D-75073-Z2) in a single low dose in the treatment of complicated infections of the urinary tract]. G Ital Chemioter 1984; 31:127-32. [PMID: 6468823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Niederman R, Amrein PC, Hartwig J. Three-dimensional structure of actin filaments and of an actin gel made with actin-binding protein. J Biophys Biochem Cytol 1983; 96:1400-13. [PMID: 6682423 PMCID: PMC2112656 DOI: 10.1083/jcb.96.5.1400] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Purified muscle actin and mixtures of actin and actin-binding protein were examined in the transmission electron microscope after fixation, critical point drying, and rotary shadowing. The three-dimensional structure of the protein assemblies was analyzed by a computer-assisted graphic analysis applicable to generalized filament networks. This analysis yielded information concerning the frequency of filament intersections, the filament length between these intersections, the angle at which filaments branch at these intersections, and the concentration of filaments within a defined volume. Purified actin at a concentration of 1 mg/ml assembled into a uniform mass of long filaments which overlap at random angles between 0 degrees and 90 degrees. Actin in the presence of macrophage actin-binding protein assembled into short, straight filaments, organized in a perpendicular branching network. The distance between branch points was inversely related to the molar ratio of actin-binding protein to actin. This distance was what would be predicted if actin filaments grew at right angles off of nucleation sites on the two ends of actin-binding protein dimers, and then annealed. The results suggest that actin in combination with actin-binding protein self-assembles to form a three-dimensional network resembling the peripheral cytoskeleton of motile cells.
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Hartwig J. [Evaluation of Alrheumum in practice-like conditions]. ZFA (Stuttgart) 1976; 52:1682-4. [PMID: 1088021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Stossel TP, Mason RJ, Hartwig J, Vaughan M. Quantitative studies of phagocytosis by polymorphonuclear leukocytes: use of emulsions to measure the initial rate of phagocytosis. J Clin Invest 1972; 51:615-24. [PMID: 4334720 PMCID: PMC302168 DOI: 10.1172/jci106851] [Citation(s) in RCA: 188] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Polymorphonuclear leukocytes suspended in Krebs-Ringer phosphate medium ingest paraffin oil containing Oil Red O emulsified with a variety of substances. Spectrophotometric determination of Oil Red O in the cells after uningested particles have been removed by differential centrifugation provides a quantitative measure of phagocytosis. This system has been used to investigate the effects of several drugs and hormones on the initial rate of phagocytosis and to approach the question of how the surface of a particle influences its acceptability as a substrate for phagocytosis. The rate of uptake of paraffin oil emulsified with bovine albumin was constant for 6 min and was proportional to cell concentration when saturating concentrations of paraffin oil emulsion were used. At lower concentrations of substrate, the initial rate of phagocytosis was directly proportional to paraffin oil concentration. The increment in glucose oxidation associated with phagocytosis varied directly with the initial rate of particle uptake. The rate of ingestion of the albumin emulsion was not altered by serum (2-20%, v/v), glucose (5-20 mM), or omission of potassium from the medium. The rate of phagocytosis was decreased 65% if magnesium was omitted, and was essentially zero in the absence of divalent cations. The initial rate of uptake was inhibited by inhibitors of glycolysis, by N-ethylmaleimide (0.05-1 mM), colchicine (0.001-0.1 mM), theophylline (1 and 2 mM), dibutyryl cyclic AMP (1 mM), hydrocortisone (2.1 mM), and ethanol (85 mM). Inhibitors of oxidative phosphorylation and dexamethasone (0.01 mM) were without effect, while insulin (2 mU/ml) slightly stimulated the phagocytic rate. Paraffin oil emulsified with different agents was used to approach the question of how the surface of a particle influences its acceptability as a substrate for phagocytosis. Emulsions prepared with nonionic detergents, methylated proteins, and proteins with a weak net charge at pH 7.4 were poorly ingested. On the other hand emulsions prepared with agents of strong net positive or negative charge were rapidly taken up. The effect of divalent cations on the rate of phagocytosis varied with the nature of the emulsifier, but was not related in any simple, direct fashion to the net surface charge of the particles. However, it has not been conclusively established that charge was the only variable of the emulsion particles employed.
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