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Heimke M, Lenz F, Rickert U, Lucius R, Cossais F. Anti-Inflammatory Properties of the SGLT2 Inhibitor Empagliflozin in Activated Primary Microglia. Cells 2022; 11:cells11193107. [PMID: 36231069 PMCID: PMC9563452 DOI: 10.3390/cells11193107] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors, including empagliflozin, are routinely used as antidiabetic drugs. Recent studies indicate that beside its beneficial effects on blood glucose level, empagliflozin may also exert vascular anti-inflammatory and neuroprotective properties. In the brain, microglia are crucial mediators of inflammation, and neuroinflammation plays a key role in neurodegenerative disorders. Dampening microglia-mediated inflammation may slow down disease progression. In this context, we investigated the immunomodulatory effect of empagliflozin on activated primary microglia. As a validated experimental model, rat primary microglial cells were activated into a pro-inflammatory state by stimulation with LPS. The influence of empagliflozin on the expression of pro-inflammatory mediators (NO, Nos2, IL6, TNF, IL1B) and on the anti-inflammatory mediator IL10 was assessed using quantitative PCR and ELISA. Further, we investigated changes in the activation of the ERK1/2 cascade by Western blot and NFkB translocation by immunostaining. We observed that empagliflozin reduces the expression of pro- and anti-inflammatory mediators in LPS-activated primary microglia. These effects might be mediated by NHE-1, rather than by SGLT2, and by the further inhibition of the ERK1/2 and NFkB pathways. Our results support putative anti-inflammatory effects of empagliflozin on microglia and suggest that SGLT2 inhibitors may exert beneficial effects in neurodegenerative disorders.
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Gellrich A, Scharfenberg F, Peters F, Sammel M, Helm O, Armbrust F, Schmidt F, Lokau J, Garbers C, Sebens S, Arnold P, Becker-Pauly C. Characterization of the Cancer-Associated Meprin Βeta Variants G45R and G89R. Front Mol Biosci 2021; 8:702341. [PMID: 34692768 PMCID: PMC8526939 DOI: 10.3389/fmolb.2021.702341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/16/2021] [Indexed: 11/23/2022] Open
Abstract
Meprin β is a metalloprotease associated with neurodegeneration, inflammation, extracellular matrix homeostasis, transendothelial cell migration, and cancer. In this study, we investigated two melanoma-associated variants of meprin β, both exhibiting a single amino acid exchange, namely, meprin β G45R and G89R. Based on the structural data of meprin β and with regard to the position of the amino acid exchanges, we hypothesized an increase in proteolytic activity in the case of the G45R variant due to the induction of a potential new activation site and a decrease in proteolytic activity from the G89R variant due to structural instability. Indeed, the G89R variant showed, overall, a reduced expression level compared to wild-type meprin β, accompanied by decreased activity and lower cell surface expression but strong accumulation in the endoplasmic reticulum. This was further supported by the analysis of the shedding of the interleukin-6 receptor (IL-6R) by meprin β and its variants. In transfected HEK cells, the G89R variant was found to generate less soluble IL-6R, whereas the expression of meprin β G45R resulted in increased shedding of the IL-6R compared to wild-type meprin β and the G89R variant. A similar tendency of the induced shedding capacity of G45R was seen for the well-described meprin β substrate CD99. Furthermore, employing an assay for cell migration in a collagen IV matrix, we observed that the transfection of wild-type meprin β and the G45R variant resulted in increased migration of HeLa cells, while the G89R variant led to diminished mobility.
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Affiliation(s)
| | | | - Florian Peters
- Department of Ophthalmology, Laboratory for Retinal Cell Biology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Sammel
- Biochemical Institute, Kiel University, Kiel, Germany
| | - Ole Helm
- Institute for Experimental Cancer Research, Kiel University, Kiel, Germany
| | - Fred Armbrust
- Biochemical Institute, Kiel University, Kiel, Germany
| | | | - Juliane Lokau
- Institute of Pathology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Christoph Garbers
- Institute of Pathology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Susanne Sebens
- Institute for Experimental Cancer Research, Kiel University, Kiel, Germany
| | - Philipp Arnold
- Institute of Functional and Clinical Anatomy, FAU Erlangen, Erlangen, Germany
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Li W, Lückstädt W, Wöhner B, Bub S, Schulz A, Socher E, Arnold P. Structural and functional properties of meprin β metalloproteinase with regard to cell signaling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119136. [PMID: 34626678 DOI: 10.1016/j.bbamcr.2021.119136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/05/2021] [Accepted: 09/06/2021] [Indexed: 10/20/2022]
Abstract
The metalloproteinase meprin β plays an important role during collagen I deposition in the skin, mucus detachment in the small intestine and also regulates the abundance of different cell surface proteins such as the interleukin-6 receptor (IL-6R), the triggering receptor expressed on myeloid cells 2 (TREM2), the cluster of differentiation 99 (CD99), the amyloid precursor protein (APP) and the cluster of differentiation 109 (CD109). With that, regulatory mechanisms that control meprin β activity and regulate its release from the cell surface to enable access to distant substrates are increasingly important. Here, we will summarize factors that alternate meprin β activity and thereby regulate its proteolytic activity on the cell surface or in the supernatant. We will also discuss cleavage of the IL-6R and TREM2 on the cell surface and compare it to CD109. CD109, as a substrate of meprin β, is cleaved within the protein core, thereby releasing defined fragments from the cell surface. At last, we will also summarize the role of proteases in general and meprin β in particular in substrate release on extracellular vesicles.
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Affiliation(s)
- Wenjia Li
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Wiebke Lückstädt
- Institute of Anatomy, Christian-Albrechts-Universität zu Kiel (CAU), Kiel, Germany
| | - Birte Wöhner
- Institute of Anatomy, Christian-Albrechts-Universität zu Kiel (CAU), Kiel, Germany
| | - Simon Bub
- Department of Molecular-Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Antonia Schulz
- Institute of Anatomy, Christian-Albrechts-Universität zu Kiel (CAU), Kiel, Germany
| | - Eileen Socher
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Philipp Arnold
- Institute of Functional and Clinical Anatomy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
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Lückstädt W, Bub S, Koudelka T, Pavlenko E, Peters F, Somasundaram P, Becker-Pauly C, Lucius R, Zunke F, Arnold P. Cell Surface Processing of CD109 by Meprin β Leads to the Release of Soluble Fragments and Reduced Expression on Extracellular Vesicles. Front Cell Dev Biol 2021; 9:622390. [PMID: 33738281 PMCID: PMC7960916 DOI: 10.3389/fcell.2021.622390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/29/2021] [Indexed: 12/21/2022] Open
Abstract
Cluster of differentiation 109 (CD109) is a glycosylphosphatidylinositol (GPI)-anchored protein expressed on primitive hematopoietic stem cells, activated platelets, CD4+ and CD8+ T cells, and keratinocytes. In recent years, CD109 was also associated with different tumor entities and identified as a possible future diagnostic marker linked to reduced patient survival. Also, different cell signaling pathways were proposed as targets for CD109 interference including the TGFβ, JAK-STAT3, YAP/TAZ, and EGFR/AKT/mTOR pathways. Here, we identify the metalloproteinase meprin β to cleave CD109 at the cell surface and thereby induce the release of cleavage fragments of different size. Major cleavage was identified within the bait region of CD109 residing in the middle of the protein. To identify the structural localization of the bait region, homology modeling and single-particle analysis were applied, resulting in a molecular model of membrane-associated CD109, which allows for the localization of the newly identified cleavage sites for meprin β and the previously published cleavage sites for the metalloproteinase bone morphogenetic protein-1 (BMP-1). Full-length CD109 localized on extracellular vesicles (EVs) was also identified as a release mechanism, and we can show that proteolytic cleavage of CD109 at the cell surface reduces the amount of CD109 sorted to EVs. In summary, we identified meprin β as the first membrane-bound protease to cleave CD109 within the bait region, provide a first structural model for CD109, and show that cell surface proteolysis correlates negatively with CD109 released on EVs.
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Affiliation(s)
- Wiebke Lückstädt
- Anatomical Institute, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Simon Bub
- Anatomical Institute, Christian-Albrechts-University Kiel, Kiel, Germany
- Department of Molecular Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Tomas Koudelka
- Systematic Proteomics and Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Egor Pavlenko
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Florian Peters
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Prasath Somasundaram
- Systematic Proteomics and Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-University Kiel, Kiel, Germany
| | | | - Ralph Lucius
- Anatomical Institute, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Friederike Zunke
- Department of Molecular Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Philipp Arnold
- Anatomical Institute, Christian-Albrechts-University Kiel, Kiel, Germany
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Arnold P, Lückstädt W, Li W, Boll I, Lokau J, Garbers C, Lucius R, Rose-John S, Becker-Pauly C. Joint Reconstituted Signaling of the IL-6 Receptor via Extracellular Vesicles. Cells 2020; 9:cells9051307. [PMID: 32456348 PMCID: PMC7291149 DOI: 10.3390/cells9051307] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022] Open
Abstract
Interleukin-6 (IL-6) signaling is a crucial regulatory event important for many biological functions, such as inflammation and tissue regeneration. Accordingly, several pathological conditions are associated with dysregulated IL-6 activity, making it an attractive therapeutic target. For instance, blockade of IL-6 or its α-receptor (IL-6R) by monoclonal antibodies has been successfully used to treat rheumatoid arthritis. However, based on different signaling modes, IL-6 function varies between pro- and anti-inflammatory activity, which is critical for therapeutic intervention. So far, three modes of IL-6 signaling have been described, the classic anti-inflammatory signaling, as well as pro-inflammatory trans-signaling, and trans-presentation. The IL-6/IL-6R complex requires an additional β-receptor (gp130), which is expressed on almost all cells of the human body, to induce STAT3 (signal transducer and activator of signal transcription 3) phosphorylation and subsequent transcriptional regulation. In contrast, the IL-6R is expressed on a limited number of cells, including hepatocytes and immune cells. However, the proteolytic release of the IL-6R enables trans-signaling on cells expressing gp130 only. Here, we demonstrate a fourth possibility of IL-6 signaling that we termed joint reconstituted signaling (JRS). We show that IL-6R on extracellular vesicles (EVs) can also be transported to and fused with other cells that lack the IL-6R on their surface. Importantly, JRS via EVs induces delayed STAT3 phosphorylation compared to the well-established trans-signaling mode. EVs isolated from human serum were already shown to carry the IL-6R, and thus this new signaling mode should be considered with regard to signal intervention.
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Affiliation(s)
- Philipp Arnold
- Anatomical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany; (W.L.); (W.L.); (R.L.)
- MSH Medical School Hamburg, Am Kaiserkai 1, 20457 Hamburg, Germany
- Correspondence: (P.A.); (C.B.-P.)
| | - Wiebke Lückstädt
- Anatomical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany; (W.L.); (W.L.); (R.L.)
| | - Wenjia Li
- Anatomical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany; (W.L.); (W.L.); (R.L.)
| | - Inga Boll
- Biochemical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 9, 24118 Kiel, Germany; (I.B.); (S.R.-J.)
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Juliane Lokau
- Institute of Pathology, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany; (J.L.); (C.G.)
| | - Christoph Garbers
- Institute of Pathology, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120 Magdeburg, Germany; (J.L.); (C.G.)
| | - Ralph Lucius
- Anatomical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany; (W.L.); (W.L.); (R.L.)
| | - Stefan Rose-John
- Biochemical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 9, 24118 Kiel, Germany; (I.B.); (S.R.-J.)
| | - Christoph Becker-Pauly
- Biochemical Institute, Christian-Albrechts-University Kiel, Otto-Hahn Platz 9, 24118 Kiel, Germany; (I.B.); (S.R.-J.)
- Correspondence: (P.A.); (C.B.-P.)
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6
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Schäffler H, Li W, Helm O, Krüger S, Böger C, Peters F, Röcken C, Sebens S, Lucius R, Becker-Pauly C, Arnold P. The cancer-associated meprin β variant G32R provides an additional activation site and promotes cancer cell invasion. J Cell Sci 2019; 132:jcs.220665. [PMID: 31076514 DOI: 10.1242/jcs.220665] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 04/23/2019] [Indexed: 12/13/2022] Open
Abstract
The extracellular metalloprotease meprin β is expressed as a homodimer and is primarily membrane bound. Meprin β can be released from the cell surface by its known sheddases ADAM10 and ADAM17. Activation of pro-meprin β at the cell surface prevents its shedding, thereby stabilizing its proteolytic activity at the plasma membrane. We show that a single amino acid exchange variant (G32R) of meprin β, identified in endometrium cancer, is more active against a peptide substrate and the IL-6 receptor than wild-type meprin β. We demonstrate that the change to an arginine residue at position 32 represents an additional activation site used by furin-like proteases in the Golgi, which consequently leads to reduced shedding by ADAM17. We investigated this meprin β G32R variant to assess cell proliferation, invasion through a collagen IV matrix and outgrowth from tumor spheroids. We found that increased meprin β G32R activity at the cell surface reduces cell proliferation, but increases cell invasion.
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Affiliation(s)
| | - Wenjia Li
- Anatomical Institute, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - Ole Helm
- Institute for Experimental Cancer Research, Arnold-Heller-Str. 3, 24105 Kiel, Germany
| | - Sandra Krüger
- Dept. of Pathology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Arnold-Heller-Str. 3/14, 24105 Kiel, Germany
| | - Christine Böger
- Dept. of Pathology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Arnold-Heller-Str. 3/14, 24105 Kiel, Germany
| | - Florian Peters
- Biochemical Institute, Otto-Hahn Platz 9, 24118 Kiel, Germany
| | - Christoph Röcken
- Dept. of Pathology, Christian-Albrechts-University and University Hospital Schleswig-Holstein, Arnold-Heller-Str. 3/14, 24105 Kiel, Germany
| | - Susanne Sebens
- Institute for Experimental Cancer Research, Arnold-Heller-Str. 3, 24105 Kiel, Germany
| | - Ralph Lucius
- Anatomical Institute, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | | | - Philipp Arnold
- Anatomical Institute, Otto-Hahn Platz 8, 24118 Kiel, Germany
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7
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Bast BO, Rickert U, Schneppenheim J, Cossais F, Wilms H, Arnold P, Lucius R. Aldosterone exerts anti-inflammatory effects on LPS stimulated microglia. Heliyon 2018; 4:e00826. [PMID: 30302409 PMCID: PMC6174543 DOI: 10.1016/j.heliyon.2018.e00826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/19/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
Over the last years, studies on microglia cell function in chronic neuro-inflammation and neuronal necrosis pointed towards an eminent role of these cells in Multiple Sclerosis, Parkinson's and Alzheimer's Disease. It was found, that microglia cell activity can be stimulated towards a pro- or an anti-inflammatory profile, depending on the stimulating signals. Therefore, investigation of receptors expressed by microglia cells and ligands influencing their activation state is of eminent interest. A receptor found to be expressed by microglia cells is the mineralocorticoid receptor. One of its ligands is Aldosterone, a naturally produced steroid hormone of the adrenal cortex, which mainly induces homeostatic and renal effects. We evaluated if the addition of Aldosterone to LPS stimulated microglia cells changes their inflammatory profile. Therefore, we assessed the levels of nitric oxide (NO), iNOS, IL-6, IL-1β, TNF-α and COX-2 in untreated, LPS-treated and LPS/Aldosterone-treated microglia cells. Furthermore we analyzed p38-MAP-Kinase and NFκB signaling within these cells. Our results indicate that the co-stimulation with Aldosterone leads to a decrease of the LPS-induced pro-inflammatory effect and thus renders Aldosterone an anti-inflammatory agent in our model system.
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Affiliation(s)
- Björn-Ole Bast
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - Uta Rickert
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - Janna Schneppenheim
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - François Cossais
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - Henrik Wilms
- Department of Neurology, Texas Tech University Health Science Center, 3601 4th Street, 79430 Lubbock, TX, USA
| | - Philipp Arnold
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
| | - Ralph Lucius
- Anatomical Institute, Christian-Albrechts-University of Kiel, Otto-Hahn Platz 8, 24118 Kiel, Germany
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8
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Lichtenthaler SF, Lemberg MK, Fluhrer R. Proteolytic ectodomain shedding of membrane proteins in mammals-hardware, concepts, and recent developments. EMBO J 2018; 37:e99456. [PMID: 29976761 PMCID: PMC6068445 DOI: 10.15252/embj.201899456] [Citation(s) in RCA: 184] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/05/2018] [Accepted: 06/18/2018] [Indexed: 12/14/2022] Open
Abstract
Proteolytic removal of membrane protein ectodomains (ectodomain shedding) is a post-translational modification that controls levels and function of hundreds of membrane proteins. The contributing proteases, referred to as sheddases, act as important molecular switches in processes ranging from signaling to cell adhesion. When deregulated, ectodomain shedding is linked to pathologies such as inflammation and Alzheimer's disease. While proteases of the "a disintegrin and metalloprotease" (ADAM) and "beta-site APP cleaving enzyme" (BACE) families are widely considered as sheddases, in recent years a much broader range of proteases, including intramembrane and soluble proteases, were shown to catalyze similar cleavage reactions. This review demonstrates that shedding is a fundamental process in cell biology and discusses the current understanding of sheddases and their substrates, molecular mechanisms and cellular localizations, as well as physiological functions of protein ectodomain shedding. Moreover, we provide an operational definition of shedding and highlight recent conceptual advances in the field. While new developments in proteomics facilitate substrate discovery, we expect that shedding is not a rare exception, but rather the rule for many membrane proteins, and that many more interesting shedding functions await discovery.
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Affiliation(s)
- Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Neuroproteomics, Klinikum rechts der Isar, School of Medicine, and Institute for Advanced Study, Technical University Munich, Munich, Germany
- Munich Center for Systems Neurology (SyNergy), Munich, Germany
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Regina Fluhrer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Biomedizinisches Centrum (BMC), Ludwig-Maximilians University of Munich, Munich, Germany
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9
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Meprin metalloproteases: Molecular regulation and function in inflammation and fibrosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2096-2104. [PMID: 28502593 DOI: 10.1016/j.bbamcr.2017.05.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/05/2017] [Accepted: 05/09/2017] [Indexed: 01/03/2023]
Abstract
The zinc-endopeptidases meprin α and meprin β are extracellular proteases involved in connective tissue homeostasis, intestinal barrier function and immunological processes. Meprins are unique among other extracellular proteases with regard to cleavage specificity and structure. Meprin α and meprin β have a strong preference for negatively charged amino acids around the scissile bond, reflected by cleavage sites identified in procollagen I, the amyloid precursor protein (APP) and the interleukin-6 receptor (IL-6R). In this review we report on recent findings that summarize the complex molecular regulation of meprins, particular folding, activation and shedding. Dysregulation of meprin α and meprin β is often associated with pathological conditions such as neurodegeneration, inflammatory bowel disease and fibrosis. Based on mouse models and patient data we suggest meprins as possible key regulators in the onset and progression of fibrotic disorders, leading to severe diseases such as pulmonary hypertension. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
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10
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Schneppenheim J, Scharfenberg F, Lucius R, Becker-Pauly C, Arnold P. Meprin β and BMP-1 are differentially regulated by CaCl 2. Cell Calcium 2017; 65:8-13. [PMID: 28365001 DOI: 10.1016/j.ceca.2017.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/14/2017] [Accepted: 03/14/2017] [Indexed: 01/13/2023]
Abstract
The two metalloproteases meprin β and bone morphogenetic protein 1 (BMP-1) are both members of the astacin protease family. They share specificity for negatively charged residues around the scissile bond and they are expressed in overlapping compartments of the human body. One important proteolytic substrate they share is pro-collagen I. Ablation of one of the two proteases however leads to different collagen I associated phenotypes in vivo. Over the last years calcium emerged as a regulator for the proteolytic activity of both enzymes. For meprin β a reduction and for BMP-1 an increase in activity was reported under increasing calcium concentrations. Here we revisit different compartments that rely on pro-collagen I maturation and explore the crystal structure of both proteases to highlight possible calcium binding sites. With this we aim to emphasize a to date underestimated regulator that influences both proteases.
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Affiliation(s)
| | | | - Ralph Lucius
- Anatomical Institute, Otto-Hahn-Platz 8, 24118 Kiel, Germany
| | | | - Philipp Arnold
- Anatomical Institute, Otto-Hahn-Platz 8, 24118 Kiel, Germany.
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11
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Becker-Pauly C, Pietrzik CU. The Metalloprotease Meprin β Is an Alternative β-Secretase of APP. Front Mol Neurosci 2017; 9:159. [PMID: 28105004 PMCID: PMC5215381 DOI: 10.3389/fnmol.2016.00159] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 12/09/2016] [Indexed: 01/08/2023] Open
Abstract
The membrane bound metalloprotease meprin β is important for collagen fibril assembly in connective tissue formation and for the detachment of the intestinal mucus layer for proper barrier function. Recent proteomic studies revealed dozens of putative new substrates of meprin β, including the amyloid precursor protein (APP). It was shown that APP is cleaved by meprin β in distinct ways, either at the β-secretase site resulting in increased levels of Aβ peptides, or at the N-terminus releasing 11 kDa, and 20 kDa peptide fragments. The latter event was discussed to be rather neuroprotective, whereas the ectodomain shedding of APP by meprin β reminiscent to BACE-1 is in line with the amyloid hypothesis of Alzheimer's disease, promoting neurodegeneration. The N-terminal 11 kDa and 20 kDa peptide fragments represent physiological cleavage products, since they are found in human brains under different diseased or non-diseased states, whereas these fragments are completely missing in brains of meprin β knock-out animals. Meprin β is not only a sheddase of adhesion molecules, such as APP, but was additionally demonstrated to cleave within the prodomain of ADAM10. Activated ADAM10, the α-secretase of APP, is then able to shed meprin β from the cell surface thereby abolishing the β-secretase activity. All together meprin β seems to be a novel player in APP processing events, even influencing other enzymes involved in APP cleavage.
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Affiliation(s)
- Christoph Becker-Pauly
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel Kiel, Germany
| | - Claus U Pietrzik
- Institute for Pathobiochemistry, University Medical Center of the Johannes Gutenberg-University Mainz Mainz, Germany
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12
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Bedau T, Peters F, Prox J, Arnold P, Schmidt F, Finkernagel M, Köllmann S, Wichert R, Otte A, Ohler A, Stirnberg M, Lucius R, Koudelka T, Tholey A, Biasin V, Pietrzik CU, Kwapiszewska G, Becker-Pauly C. Ectodomain shedding of CD99 within highly conserved regions is mediated by the metalloprotease meprin β and promotes transendothelial cell migration. FASEB J 2016; 31:1226-1237. [PMID: 28003343 DOI: 10.1096/fj.201601113r] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/06/2016] [Indexed: 11/11/2022]
Abstract
The adhesion molecule CD99 is essential for the transendothelial migration of leukocytes. In this study, we used biochemical and cellular assays to show that CD99 undergoes ectodomain shedding by the metalloprotease meprin β and subsequent intramembrane proteolysis by γ-secretase. The cleavage site in CD99 was identified by mass spectrometry within an acidic region highly conserved through different vertebrate species. This finding fits perfectly to the unique cleavage specificity of meprin β with a strong preference for aspartate residues and suggests coevolution of protease and substrate. We hypothesized that limited CD99 cleavage by meprin β would alter cellular transendothelial migration (TEM) behavior in tissue remodeling processes, such as inflammation and cancer. Indeed, meprin β induced cell migration of Lewis lung carcinoma cells in an in vitro TEM assay. Accordingly, deficiency of meprin β in Mep1b-/- mice resulted in significantly increased CD99 protein levels in the lung. Therefore, meprin β could serve as a therapeutic target, given that in a proof-of-concept approach we showed accumulation of CD99 protein in lungs of meprin β inhibitor-treated mice.-Bedau, T., Peters, F., Prox, J., Arnold, P., Schmidt, F., Finkernagel, M., Köllmann, S., Wichert, R., Otte, A., Ohler, A., Stirnberg, M., Lucius, R., Koudelka, T., Tholey, A., Biasin, V., Pietrzik, C. U., Kwapiszewska, G., Becker-Pauly, C. Ectodomain shedding of CD99 within highly conserved regions is mediated by the metalloprotease meprin β and promotes transendothelial cell migration.
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Affiliation(s)
- Tillmann Bedau
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Florian Peters
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Johannes Prox
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | | | - Frederike Schmidt
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Malin Finkernagel
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Sandra Köllmann
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Rielana Wichert
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Anna Otte
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany
| | - Anke Ohler
- Institute of Pathobiochemistry, University Medical Centre, Johannes Gutenberg University of Mainz, Mainz, Germany
| | | | - Ralph Lucius
- Anatomical Institute, University of Kiel, Kiel, Germany
| | - Tomas Koudelka
- Institute of Experimental Medicine, University of Kiel, Kiel, Germany; and
| | - Andreas Tholey
- Institute of Experimental Medicine, University of Kiel, Kiel, Germany; and
| | - Valentina Biasin
- Ludwig Boltzmann Institute, Lung Vascular Research, Graz, Austria
| | - Claus U Pietrzik
- Institute of Pathobiochemistry, University Medical Centre, Johannes Gutenberg University of Mainz, Mainz, Germany
| | | | - Christoph Becker-Pauly
- Unit for Degradomics of the Protease Web, Institute of Biochemistry, University of Kiel, Kiel, Germany;
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13
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Arnold P, Koopmann L, Peters F, Birkenfeld F, Goff SVL, Damm T, Qin C, Moali C, Lucius R, Becker-Pauly C. Deficiency of the DSPP-cleaving enzymes meprin α and meprin β does not result in dentin malformation in mice. Cell Tissue Res 2016; 367:351-358. [PMID: 27628095 DOI: 10.1007/s00441-016-2498-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/19/2016] [Indexed: 01/22/2023]
Abstract
Formation of dentin requires the maturation of procollagen I and the proteolytic processing of the dentin sialophosphoprotein (DSPP). These cleavage events can be facilitated by the metalloproteinases meprin α and meprin β as well as by bone morphogenetic protein 1 (BMP-1). All three enzymes have been shown to play important roles during collagen I maturation in vivo and their potential in cleaving DSPP was demonstrated in vitro. Hence, it has been discussed whether meprin α, meprin β, BMP-1 or all three are crucial factors in the onset and progression of dentin-related diseases and this issue is addressed here. In this study, we compare the incisors and molars of meprin α (Mep1a -/-)- and meprin β (Mep1b -/-)-deficient mice with wild-type (WT) controls on the macroscopic and microscopic level. The dentin was evaluated towards the bone mineral density, dentin volume, calcification and collagen matrix integrity. Using immunohistochemistry, we could identify meprin β, BMP-1 and DSPP/DSP in the pre-dentin of WT mice. Nevertheless, no significant dentin malformation was observed in Mep1b -/- or Mep1a -/- deficient mice.
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Affiliation(s)
- Philipp Arnold
- Anatomical Institute, Kiel University, Otto-Hahn-Platz 8, 24118, Kiel, Germany.
| | - Lara Koopmann
- Anatomical Institute, Kiel University, Otto-Hahn-Platz 8, 24118, Kiel, Germany
| | - Florian Peters
- Biochemical Institute, Kiel University, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Falk Birkenfeld
- Department of Oral and Maxillofacial Surgery, University Hospital Schleswig-Holstein, Arnold-Heller-Str. 16, 24105, Kiel, Germany
| | - Sandrine Vadon-Le Goff
- Department of Tissue Biology and Therapeutic Engineering, Unité Mixte de Recherche 5305, Centre National de la Recherche Scientifique/University of Lyon, 69367, Lyon Cedex 7, France
| | - Timo Damm
- Section Biomedical Imaging, Department of Radiology and Neurology, University Hospital Schleswig-Holstein, Am Botanischen Garten 18, 24118, Kiel, Germany
| | - Chunlin Qin
- Department of Biomedical Sciences, Texas A&M University Baylor College of Dentistry, 3302 Gaston Avenue, 75246, Dallas, TX, USA
| | - Catherine Moali
- Department of Tissue Biology and Therapeutic Engineering, Unité Mixte de Recherche 5305, Centre National de la Recherche Scientifique/University of Lyon, 69367, Lyon Cedex 7, France
| | - Ralph Lucius
- Anatomical Institute, Kiel University, Otto-Hahn-Platz 8, 24118, Kiel, Germany
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14
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Schmidt F, Müller M, Prox J, Arnold P, Schönherr C, Tredup C, Minder P, Ebsen H, Janssen O, Annaert W, Pietrzik C, Schmidt-Arras D, Sterchi EE, Becker-Pauly C. Tetraspanin 8 is an interactor of the metalloprotease meprin β within tetraspanin-enriched microdomains. Biol Chem 2016; 397:857-69. [DOI: 10.1515/hsz-2016-0126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/04/2016] [Indexed: 11/15/2022]
Abstract
Abstract
Meprin β is a dimeric type I transmembrane protein and acts as an ectodomain sheddase at the cell surface. It has been shown that meprin β cleaves the amyloid precursor protein (APP), thereby releasing neurotoxic amyloid β peptides and implicating a role of meprin β in Alzheimer’s disease. In order to identify non-proteolytic regulators of meprin β, we performed a split ubiquitin yeast two-hybrid screen using a small intestinal cDNA library. In this screen we identified tetraspanin 8 (TSPAN8) as interaction partner for meprin β. As several members of the tetraspanin family were described to interact with metalloproteases thereby affecting their localization and/or activity, we hypothesized similar functions of TSPAN8 in the regulation of meprin β. We employed cell biological methods to confirm direct binding of TSPAN8 to meprin β. Surprisingly, we did not observe an effect of TSPAN8 on the catalytic activity of meprin β nor on the specific cleavage of its substrate APP. However, both proteins were identified as present in tetraspanin-enriched microdomains. Therefore we hypothesize that TSPAN8 might be important for the orchestration of meprin β at the cell surface with impact on certain proteolytic processes that have to be further identified.
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15
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Arnold P, Rickert U, Helmers AK, Spreu J, Schneppenheim J, Lucius R. Trefoil factor 3 shows anti-inflammatory effects on activated microglia. Cell Tissue Res 2016; 365:3-11. [PMID: 26899249 DOI: 10.1007/s00441-016-2370-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 01/27/2016] [Indexed: 12/25/2022]
Abstract
Microglial cells are a major source of pro-inflammatory cytokines during central nervous system (CNS) inflammation. They can develop a pro-inflammatory M1 phenotype and an anti-inflammatory M2 phenotype. Shifting the phenotype from M1 to M2 might be an important mechanism to overcome CNS inflammation and to prevent or reduce neuronal damage. Here, we demonstrate that the anti-inflammatory protein trefoil factor 3 (TFF3) is secreted by astrocytes and that its transcription is significantly reduced after incubation with lipopolysaccharide (LPS). Moreover, we demonstrate that microglial cells cultured in the presence of TFF3 show reduced expression and secretion of pro-inflammatory cytokines after LPS stimulation.
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Affiliation(s)
- Philipp Arnold
- Anatomical Institute, Otto-Hahn Platz 8, 24188, Kiel, Germany
| | - Uta Rickert
- Anatomical Institute, Otto-Hahn Platz 8, 24188, Kiel, Germany
| | - Ann-Kristin Helmers
- Anatomical Institute, Otto-Hahn Platz 8, 24188, Kiel, Germany.,Institute of Neurosurgery UKSH Kiel, Arnold-Heller-Straße 3, 24105, Kiel, Germany
| | - Jessica Spreu
- Anatomical Institute, Otto-Hahn Platz 8, 24188, Kiel, Germany
| | | | - Ralph Lucius
- Anatomical Institute, Otto-Hahn Platz 8, 24188, Kiel, Germany.
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16
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Schönherr C, Bien J, Isbert S, Wichert R, Prox J, Altmeppen H, Kumar S, Walter J, Lichtenthaler SF, Weggen S, Glatzel M, Becker-Pauly C, Pietrzik CU. Generation of aggregation prone N-terminally truncated amyloid β peptides by meprin β depends on the sequence specificity at the cleavage site. Mol Neurodegener 2016; 11:19. [PMID: 26895626 PMCID: PMC4759862 DOI: 10.1186/s13024-016-0084-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 02/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The metalloprotease meprin β cleaves the Alzheimer's Disease (AD) relevant amyloid precursor protein (APP) as a β-secretase reminiscent of BACE-1, however, predominantly generating N-terminally truncated Aβ2-x variants. RESULTS Herein, we observed increased endogenous sAPPα levels in the brains of meprin β knock-out (ko) mice compared to wild-type controls. We further analyzed the cellular interaction of APP and meprin β and found that cleavage of APP by meprin β occurs prior to endocytosis. The N-terminally truncated Aβ2-40 variant shows increased aggregation propensity compared to Aβ1-40 and acts even as a seed for Aβ1-40 aggregation. Additionally, we observed that different APP mutants affect the catalytic properties of meprin β and that, interestingly, meprin β is unable to generate N-terminally truncated Aβ peptides from Swedish mutant APP (APPswe). CONCLUSION Concluding, we propose that meprin β may be involved in the generation of N-terminally truncated Aβ2-x peptides of APP, but acts independently from BACE-1.
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Affiliation(s)
- Caroline Schönherr
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Jessica Bien
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Simone Isbert
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Rielana Wichert
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Johannes Prox
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Hermann Altmeppen
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Sathish Kumar
- Department of Neurology, Molecular Cell Biology, University of Bonn, 53127, Bonn, Germany
| | - Jochen Walter
- Department of Neurology, Molecular Cell Biology, University of Bonn, 53127, Bonn, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE) and Neuroproteomics, Klinikum rechts der Isar, Technische Universität München, 81675, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sascha Weggen
- Department of Neuropathology, Heinrich Heine University, 40225, Duesseldorf, Germany
| | - Markus Glatzel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Christoph Becker-Pauly
- Institute of Biochemistry, Unit for Degradomics of the Protease Web, Christian-Albrechts-University, Otto-Hahn-Platz 9, 24118, Kiel, Germany.
| | - Claus U Pietrzik
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Duesbergweg 6, 55128, Mainz, Germany.
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