1
|
Hu A, Schmidt MHH, Heinig N. Microglia in retinal angiogenesis and diabetic retinopathy. Angiogenesis 2024:10.1007/s10456-024-09911-1. [PMID: 38564108 DOI: 10.1007/s10456-024-09911-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 02/18/2024] [Indexed: 04/04/2024]
Abstract
Diabetic retinopathy has a high probability of causing visual impairment or blindness throughout the disease progression and is characterized by the growth of new blood vessels in the retina at an advanced, proliferative stage. Microglia are a resident immune population in the central nervous system, known to play a crucial role in regulating retinal angiogenesis in both physiological and pathological conditions, including diabetic retinopathy. Physiologically, they are located close to blood vessels and are essential for forming new blood vessels (neovascularization). In diabetic retinopathy, microglia become widely activated, showing a distinct polarization phenotype that leads to their accumulation around neovascular tufts. These activated microglia induce pathogenic angiogenesis through the secretion of various angiogenic factors and by regulating the status of endothelial cells. Interestingly, some subtypes of microglia simultaneously promote the regression of neovascularization tufts and normal angiogenesis in neovascularization lesions. Modulating the state of microglial activation to ameliorate neovascularization thus appears as a promising potential therapeutic approach for managing diabetic retinopathy.
Collapse
Affiliation(s)
- Aiyan Hu
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany.
| | - Nora Heinig
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307, Dresden, Germany.
| |
Collapse
|
2
|
Vogt M, Unnikrishnan MK, Heinig N, Schumann U, Schmidt MHH, Barth K. c-Cbl Regulates Murine Subventricular Zone-Derived Neural Progenitor Cells in Dependence of the Epidermal Growth Factor Receptor. Cells 2023; 12:2400. [PMID: 37830613 PMCID: PMC10572332 DOI: 10.3390/cells12192400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/15/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023] Open
Abstract
The localization, expression, and physiological role of regulatory proteins in the neurogenic niches of the brain is fundamental to our understanding of adult neurogenesis. This study explores the expression and role of the E3-ubiquitin ligase, c-Cbl, in neurogenesis within the subventricular zone (SVZ) of mice. In vitro neurosphere assays and in vivo analyses were performed in specific c-Cbl knock-out lines to unravel c-Cbl's role in receptor tyrosine kinase signaling, including the epidermal growth factor receptor (EGFR) pathway. Our findings suggest that c-Cbl is significantly expressed within EGFR-expressing cells, playing a pivotal role in neural stem cell proliferation and differentiation. However, c-Cbl's function extends beyond EGFR signaling, as its loss upon knock-out stimulated progenitor cell proliferation in neurosphere cultures. Yet, this effect was not detected in hippocampal progenitor cells, reflecting the lack of the EGFR in the hippocampus. In vivo, c-Cbl exerted only a minor proneurogenic influence with no measurable impact on the formation of adult-born neurons. In conclusion, c-Cbl regulates neural stem cells in the subventricular zone via the EGFR pathway but, likely, its loss is compensated by other signaling modules in vivo.
Collapse
|
3
|
McDonald B, Barth K, Schmidt MHH. The origin of brain malignancies at the blood-brain barrier. Cell Mol Life Sci 2023; 80:282. [PMID: 37688612 PMCID: PMC10492883 DOI: 10.1007/s00018-023-04934-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/11/2023]
Abstract
Despite improvements in extracranial therapy, survival rate for patients suffering from brain metastases remains very poor. This is coupled with the incidence of brain metastases continuing to rise. In this review, we focus on core contributions of the blood-brain barrier to the origin of brain metastases. We first provide an overview of the structure and function of the blood-brain barrier under physiological conditions. Next, we discuss the emerging idea of a pre-metastatic niche, namely that secreted factors and extracellular vesicles from a primary tumor site are able to travel through the circulation and prime the neurovasculature for metastatic invasion. We then consider the neurotropic mechanisms that circulating tumor cells possess or develop that facilitate disruption of the blood-brain barrier and survival in the brain's parenchyma. Finally, we compare and contrast brain metastases at the blood-brain barrier to the primary brain tumor, glioma, examining the process of vessel co-option that favors the survival and outgrowth of brain malignancies.
Collapse
Affiliation(s)
- Brennan McDonald
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany.
| | - Kathrin Barth
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany
| |
Collapse
|
4
|
Kolothara Unnikrishnan M, Schmidt MHH. Editorial for "Impact of Regorafenib on Endothelial Transdifferentiation of Glioblastoma Stem-like Cells". Cancers (Basel) 2023; 15:3830. [PMID: 37568645 PMCID: PMC10417816 DOI: 10.3390/cancers15153830] [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] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most frequently occurring form of malignant primary brain tumor in adults [...].
Collapse
Affiliation(s)
| | - Mirko H. H. Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307 Dresden, Germany;
| |
Collapse
|
5
|
Mahajan S, Schmidt MHH. Distinct Lineage of Slow-Cycling Cells Amidst the Prevailing Heterogeneity in Glioblastoma. Cancers (Basel) 2023; 15:3843. [PMID: 37568659 PMCID: PMC10417372 DOI: 10.3390/cancers15153843] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Glioblastoma (GBM) is the most aggressive form of primary brain tumor in adults [...].
Collapse
Affiliation(s)
| | - Mirko H. H. Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307 Dresden, Germany
| |
Collapse
|
6
|
Barth K, Vasić V, McDonald B, Heinig N, Wagner MC, Schumann U, Röhlecke C, Bicker F, Schumann L, Radyushkin K, Baumgart J, Tenzer S, Zipp F, Meinhardt M, Alitalo K, Tegeder I, Schmidt MHH. Correction: EGFL7 loss correlates with increased VEGF-D expression, upregulating hippocampal adult neurogenesis and improving spatial learning and memory. Cell Mol Life Sci 2023; 80:201. [PMID: 37439854 PMCID: PMC10345019 DOI: 10.1007/s00018-023-04835-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2023] [Indexed: 07/14/2023]
Affiliation(s)
- Kathrin Barth
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
| | - Verica Vasić
- Institute of Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Brennan McDonald
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
| | - Nora Heinig
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
| | - Marc Christoph Wagner
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
- Institute of Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, School of Medicine, Dresden, Germany
| | - Ulrike Schumann
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
| | - Cora Röhlecke
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany
| | - Frank Bicker
- Institute of Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Lana Schumann
- Institute of Pathology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Konstantin Radyushkin
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Mouse Behavior Outcome Unit, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jan Baumgart
- Translational Animal Research Center (TARC), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Focus Program Immunotherapy (FZI), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Frauke Zipp
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Focus Program Immunotherapy (FZI), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Department of Neurology, Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Matthias Meinhardt
- Institute of Pathology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Kari Alitalo
- Translational Cancer Medicine Program and iCAN Digital Precision Cancer Medicine Flagship, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Hospital Frankfurt Am Main, Frankfurt, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307, Dresden, Germany.
| |
Collapse
|
7
|
Vaid S, Schmidt MHH. Migration-Associated Transportome and Therapeutic Potential in Glioblastoma Multiforme (GBM). Cancers (Basel) 2023; 15:3514. [PMID: 37444623 DOI: 10.3390/cancers15133514] [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] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
GBM is a highly aggressive and very common malignant form of primary brain tumors in adults [...].
Collapse
Affiliation(s)
- Samir Vaid
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307 Dresden, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr 74, 01307 Dresden, Germany
| |
Collapse
|
8
|
Stepien BK, Pawolski V, Wagner MC, Kurth T, Schmidt MHH, Epperlein HH. The Role of Posterior Neural Plate-Derived Presomitic Mesoderm (PSM) in Trunk and Tail Muscle Formation and Axis Elongation. Cells 2023; 12:cells12091313. [PMID: 37174713 PMCID: PMC10177618 DOI: 10.3390/cells12091313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 03/22/2023] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Elongation of the posterior body axis is distinct from that of the anterior trunk and head. Early drivers of posterior elongation are the neural plate/tube and notochord, later followed by the presomitic mesoderm (PSM), together with the neural tube and notochord. In axolotl, posterior neural plate-derived PSM is pushed posteriorly by convergence and extension of the neural plate. The PSM does not go through the blastopore but turns anteriorly to join the gastrulated paraxial mesoderm. To gain a deeper understanding of the process of axial elongation, a detailed characterization of PSM morphogenesis, which precedes somite formation, and of other tissues (such as the epidermis, lateral plate mesoderm and endoderm) is needed. We investigated these issues with specific tissue labelling techniques (DiI injections and GFP+ tissue grafting) in combination with optical tissue clearing and 3D reconstructions. We defined a spatiotemporal order of PSM morphogenesis that is characterized by changes in collective cell behaviour. The PSM forms a cohesive tissue strand and largely retains this cohesiveness even after epidermis removal. We show that during embryogenesis, the PSM, as well as the lateral plate and endoderm move anteriorly, while the net movement of the axis is posterior.
Collapse
Affiliation(s)
- Barbara K Stepien
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01062 Dresden, Germany
| | - Verena Pawolski
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01062 Dresden, Germany
| | - Marc-Christoph Wagner
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01062 Dresden, Germany
| | - Thomas Kurth
- Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Electron Microscopy and Histology Facility, Technische Universität Dresden, 01062 Dresden, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01062 Dresden, Germany
| | - Hans-Henning Epperlein
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01062 Dresden, Germany
| |
Collapse
|
9
|
Barth K, Vasić V, McDonald B, Heinig N, Wagner MC, Schumann U, Röhlecke C, Bicker F, Schumann L, Radyushkin K, Baumgart J, Tenzer S, Zipp F, Meinhardt M, Alitalo K, Tegeder I, Schmidt MHH. EGFL7 loss correlates with increased VEGF-D expression, upregulating hippocampal adult neurogenesis and improving spatial learning and memory. Cell Mol Life Sci 2023; 80:54. [PMID: 36715759 PMCID: PMC9886625 DOI: 10.1007/s00018-023-04685-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 01/31/2023]
Abstract
Neural stem cells reside in the subgranular zone, a specialized neurogenic niche of the hippocampus. Throughout adulthood, these cells give rise to neurons in the dentate gyrus, playing an important role in learning and memory. Given that these core cognitive processes are disrupted in numerous disease states, understanding the underlying mechanisms of neural stem cell proliferation in the subgranular zone is of direct practical interest. Here, we report that mature neurons, neural stem cells and neural precursor cells each secrete the neurovascular protein epidermal growth factor-like protein 7 (EGFL7) to shape this hippocampal niche. We further demonstrate that EGFL7 knock-out in a Nestin-CreERT2-based mouse model produces a pronounced upregulation of neurogenesis within the subgranular zone. RNA sequencing identified that the increased expression of the cytokine VEGF-D correlates significantly with the ablation of EGFL7. We substantiate this finding with intraventricular infusion of VEGF-D upregulating neurogenesis in vivo and further show that VEGF-D knock-out produces a downregulation of neurogenesis. Finally, behavioral studies in EGFL7 knock-out mice demonstrate greater maintenance of spatial memory and improved memory consolidation in the hippocampus by modulation of pattern separation. Taken together, our findings demonstrate that both EGFL7 and VEGF-D affect neurogenesis in the adult hippocampus, with the ablation of EGFL7 upregulating neurogenesis, increasing spatial learning and memory, and correlating with increased VEGF-D expression.
Collapse
Affiliation(s)
- Kathrin Barth
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| | - Verica Vasić
- Institute of Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany ,Institute of Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Brennan McDonald
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| | - Nora Heinig
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| | - Marc-Christoph Wagner
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany ,Institute of Medical Informatics and Biometry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany
| | - Ulrike Schumann
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| | - Cora Röhlecke
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| | - Frank Bicker
- Institute of Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany ,Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Lana Schumann
- Institute of Clinical Pharmacology, Goethe-University Hospital Frankfurt Am Main, Frankfurt, Germany
| | - Konstantin Radyushkin
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany ,Mouse Behavior Outcome Unit, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jan Baumgart
- Translational Animal Research Center (TARC), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany ,Focus Program Immunotherapy (FZI), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Frauke Zipp
- Focus Program Translational Neuroscience (FTN), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany ,Focus Program Immunotherapy (FZI), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany ,Department of Neurology, Rhine-Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Matthias Meinhardt
- Institute of Pathology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Kari Alitalo
- Translational Cancer Medicine Program and iCAN Digital Precision Cancer Medicine Flagship, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Hospital Frankfurt Am Main, Frankfurt, Germany
| | - Mirko H. H. Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Fetscherstr. 74, 01307 Dresden, Germany
| |
Collapse
|
10
|
Schott K, Majer C, Bulashevska A, Childs L, Schmidt MHH, Rajalingam K, Munder M, König R. SAMHD1 in cancer: curse or cure? J Mol Med (Berl) 2021; 100:351-372. [PMID: 34480199 PMCID: PMC8843919 DOI: 10.1007/s00109-021-02131-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 07/15/2021] [Revised: 07/15/2021] [Accepted: 08/12/2021] [Indexed: 12/12/2022]
Abstract
Human sterile α motif and HD domain-containing protein 1 (SAMHD1), originally described as the major cellular deoxyribonucleoside triphosphate triphosphohydrolase (dNTPase) balancing the intracellular deoxynucleotide (dNTP) pool, has come recently into focus of cancer research. As outlined in this review, SAMHD1 has been reported to be mutated in a variety of cancer types and the expression of SAMHD1 is dysregulated in many cancers. Therefore, SAMHD1 is regarded as a tumor suppressor in certain tumors. Moreover, it has been proposed that SAMHD1 might fulfill the requirements of a driver gene in tumor development or might promote a so-called mutator phenotype. Besides its role as a dNTPase, several novel cellular functions of SAMHD1 have come to light only recently, including a role as negative regulator of innate immune responses and as facilitator of DNA end resection during DNA replication and repair. Therefore, SAMHD1 can be placed at the crossroads of various cellular processes. The present review summarizes the negative role of SAMHD1 in chemotherapy sensitivity, highlights reported SAMHD1 mutations found in various cancer types, and aims to discuss functional consequences as well as underlying mechanisms of SAMHD1 dysregulation potentially involved in cancer development.
Collapse
Affiliation(s)
- Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Catharina Majer
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Alla Bulashevska
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Liam Childs
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany
| | - Krishnaraj Rajalingam
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- University Cancer Center Mainz, University Medical Center Mainz, Mainz, Germany
| | - Markus Munder
- Third Department of Medicine, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany.
| |
Collapse
|
11
|
Abstract
The enteric nervous system (ENS) constitutes the largest part of the peripheral nervous system. In recent years, ENS development and its neurogenetic capacity in homeostasis and allostasishave gained increasing attention. Developmentally, the neural precursors of the ENS are mainly derived from vagal and sacral neural crest cell portions. Furthermore, Schwann cell precursors, as well as endodermal pancreatic progenitors, participate in ENS formation. Neural precursorsenherite three subpopulations: a bipotent neuron-glia, a neuronal-fated and a glial-fated subpopulation. Typically, enteric neural precursors migrate along the entire bowel to the anal end, chemoattracted by glial cell-derived neurotrophic factor (GDNF) and endothelin 3 (EDN3) molecules. During migration, a fraction undergoes differentiation into neurons and glial cells. Differentiation is regulated by bone morphogenetic proteins (BMP), Hedgehog and Notch signalling. The fully formed adult ENS may react to injury and damage with neurogenesis and gliogenesis. Nevertheless, the origin of differentiating cells is currently under debate. Putative candidates are an embryonic-like enteric neural progenitor population, Schwann cell precursors and transdifferentiating glial cells. These cells can be isolated and propagated in culture as adult ENS progenitors and may be used for cell transplantation therapies for treating enteric aganglionosis in Chagas and Hirschsprung's diseases.
Collapse
Affiliation(s)
| | - Mirko H. H. Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01307 Dresden, Germany;
| |
Collapse
|
12
|
Abstract
Excessive abnormal angiogenesis plays a pivotal role in tumor progression and is a hallmark of solid tumors. This process is driven by an imbalance between pro- and anti-angiogenic factors dominated by the tissue hypoxia-triggered overproduction of vascular endothelial growth factor (VEGF). VEGF-mediated signaling has quickly become one of the most promising anti-angiogenic therapeutic targets in oncology. Nevertheless, the clinical efficacy of this approach is severely limited in certain tumor types or shows only transient efficacy in patients. Acquired or intrinsic therapy resistance associated with anti-VEGF monotherapeutic approaches indicates the necessity of a paradigm change when targeting neoangiogenesis in solid tumors. In this context, the elaboration of the conceptual framework of “vessel normalization” might be a promising approach to increase the efficacy of anti-angiogenic therapies and the survival rates of patients. Indeed, the promotion of vessel maturation instead of regressing tumors by vaso-obliteration could result in reduced tumor hypoxia and improved drug delivery. The implementation of such anti-angiogenic strategies, however, faces several pitfalls due to the potential involvement of multiple pro-angiogenic factors and modulatory effects of the innate and adaptive immune system. Thus, effective treatments bypassing relapses associated with anti-VEGF monotherapies or breaking the intrinsic therapy resistance of solid tumors might use combination therapies or agents with a multimodal mode of action. This review enumerates some of the current approaches and possible future directions of treating solid tumors by targeting neovascularization.
Collapse
Affiliation(s)
- József Jászai
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01307 Dresden, Germany.
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, 01307 Dresden, Germany.
- German Cancer Consortium (DKTK), Partner Site Dresden, 01307 Dresden, Germany.
- German Cancer Research Center (DKFZ), 61920 Heidelberg, Germany.
| |
Collapse
|
13
|
Neirinckx V, Hau AC, Schuster A, Fritah S, Tiemann K, Klein E, Nazarov PV, Matagne A, Szpakowska M, Meyrath M, Chevigné A, Schmidt MHH, Niclou SP. The soluble form of pan-RTK inhibitor and tumor suppressor LRIG1 mediates downregulation of AXL through direct protein-protein interaction in glioblastoma. Neurooncol Adv 2019; 1:vdz024. [PMID: 32642659 PMCID: PMC7212925 DOI: 10.1093/noajnl/vdz024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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] [Indexed: 12/28/2022] Open
Abstract
Background Targeted approaches for inhibiting epidermal growth factor receptor (EGFR) and other receptor tyrosine kinases (RTKs) in glioblastoma (GBM) have led to therapeutic resistance and little clinical benefit, raising the need for the development of alternative strategies. Endogenous LRIG1 (Leucine-rich Repeats and ImmunoGlobulin-like domains protein 1) is an RTK inhibitory protein required for stem cell maintenance, and we previously demonstrated the soluble ectodomain of LRIG1 (sLRIG1) to potently inhibit GBM growth in vitro and in vivo. Methods Here, we generated a recombinant protein of the ectodomain of LRIG1 (sLRIG1) and determined its activity in various cellular GBM models including patient-derived stem-like cells and patient organoids. We used proliferation, adhesion, and invasion assays, and performed gene and protein expression studies. Proximity ligation assay and NanoBiT complementation technology were applied to assess protein-protein interactions. Results We show that recombinant sLRIG1 downregulates EGFRvIII but not EGFR, and reduces proliferation in GBM cells, irrespective of their EGFR expression status. We find that sLRIG1 targets and downregulates a wide range of RTKs, including AXL, and alters GBM cell adhesion. Mechanistically, we demonstrate that LRIG1 interferes with AXL but not with EGFR dimerization. Conclusions These results identify AXL as a novel sLRIG1 target and show that LRIG1-mediated RTK downregulation depends on direct protein interaction. The pan-RTK inhibitory activity of sLRIG1 warrants further investigation for new GBM treatment approaches.
Collapse
Affiliation(s)
- Virginie Neirinckx
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Ann-Christin Hau
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Anne Schuster
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Sabrina Fritah
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Katja Tiemann
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Eliane Klein
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - Petr V Nazarov
- Proteome and Genome Research Unit, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| | - André Matagne
- Center for Protein Engineering, University of Liège, Liège, Belgium
| | - Martyna Szpakowska
- Immuno-Pharmacology and Interactomics, Department of Infection and Immunity, Luxembourg Institute of Health, Luxembourg, Germany
| | - Max Meyrath
- Immuno-Pharmacology and Interactomics, Department of Infection and Immunity, Luxembourg Institute of Health, Luxembourg, Germany
| | - Andy Chevigné
- Immuno-Pharmacology and Interactomics, Department of Infection and Immunity, Luxembourg Institute of Health, Luxembourg, Germany
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Simone P Niclou
- NorLux Neuro-Oncology Laboratory, Department of Oncology, Luxembourg Institute of Health, Luxembourg
| |
Collapse
|
14
|
Neirinckx V, Hau A, Schuster A, Fritah S, Chevigné A, Schmidt MHH, Niclou SP. P11.09 Pan-RTK inhibition of sLRIG1 mediates AXL downregulation in Glioblastoma. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.155] [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] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
INTRODUCTION
Aberrant regulation of receptor tyrosine kinase (RTK) activity is characteristic of Glioblastoma (GBM). However, RTK-based targeted therapies have been largely unsuccessful in GBM patients, partially due to the complexity and redundance of RTK signaling. LRIG1 (Leucine-rich Repeats and ImmunoGlobulindomains protein 1) is known as an endogenous inhibitor of epidermal growth factor receptor (EGFR) during health and disease, however its mechanism of action is poorly understood. We previously showed that the soluble form of LRIG1 potently inhibits of GBM growth in vivo, irrespective of EGFR expression level and status, suggesting the involvement of other RTKs. Here, we aimed to shed light on the molecular mechanisms underlying its anti-cancer activity.
MATERIAL AND METHODS
We generated a recombinant human soluble LRIG1 protein by expressing LRIG1 ectodomain in insect cells via baculovirus infection and subsequent His-tag purification. rh-sLRIG1 was applied in the medium of classical GBM cell lines, patient-derived GBM stem-like cells and patient-derived 3D tumor organoids. Using different cell-based assays, cell proliferation, invasion, cell morphology, as well as protein expression and protein-protein interactions were investigated.
RESULTS
We find that recombinant sLRIG1 efficiently reduces proliferation, invasion and viability of GBM cells and patient-derived organoids, and modulates cytoskeleton proteins and cell shape. In line with previous data, the effect of recombinant sLRIG1 is independent of EGFR expression. Interestingly sLRIG1 regulates several RTKs by direct protein downregulation, including AXL, while EGFR expression is not affected. At the molecular level, we find that sLRIG1 interferes with AXL dimerization, while no protein interaction with EGFR is detected.
CONCLUSION
We identify AXL as a novel LRIG1 target and provide evidence that sLRIG1-mediated RTK downregulation requires direct protein-protein interaction. These data pave the way for a potential therapeutic application of recombinant sLRIG1 in the inhibition of growth factor signaling in GBM.
Collapse
Affiliation(s)
- V Neirinckx
- NorLux Neuro-Oncology Laboratory, Dept of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - A Hau
- NorLux Neuro-Oncology Laboratory, Dept of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - A Schuster
- NorLux Neuro-Oncology Laboratory, Dept of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - S Fritah
- NorLux Neuro-Oncology Laboratory, Dept of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - A Chevigné
- Immuno-pharmacology and interactomics, Department of Infection and Immunity, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - M H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - S P Niclou
- NorLux Neuro-Oncology Laboratory, Dept of Oncology, Luxembourg Institute of Health, Luxembourg, Luxembourg
| |
Collapse
|
15
|
Schmidt MHH, Broll R, Bruch HP, Duchrow M. Correction to: The proliferation marker pKi-67 becomes masked to MIB-1 staining after expression of its tandem repeats. Histochem Cell Biol 2018; 151:275. [PMID: 30460406 DOI: 10.1007/s00418-018-1755-9] [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] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the PubMed citation records, the author's name shows.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Henry Ford Hospital, Hermelin Brain Tumor Center, Department of Neurosurgery, 2799 W. Grand Blvd., Detroit, MI, 48202, USA
| | - Rainer Broll
- Surgical Research Laboratory, Department of Surgery, Medical University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Hans-Peter Bruch
- Surgical Research Laboratory, Department of Surgery, Medical University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Michael Duchrow
- Surgical Research Laboratory, Department of Surgery, Medical University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
| |
Collapse
|
16
|
Neirinckx V, Schuster A, Chevigné A, Schmidt MHH, Niclou SP. OS1.5 Harnessing soluble LRIG1 for pan-RTK targeting in glioblastoma. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy139.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- V Neirinckx
- Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - A Schuster
- Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - A Chevigné
- Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - M H H Schmidt
- Johannes Gutenberg University, Mainz, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - S P Niclou
- Luxembourg Institute of Health, Luxembourg, Luxembourg
- KG Jebsen Brain Tumour Research Center, Bergen, Norway
| |
Collapse
|
17
|
Stankovic ND, Hoppmann N, Teodorczyk M, Kim EL, Bros M, Giese A, Zipp F, Schmidt MHH. No role of IFITM3 in brain tumor formation in vivo. Oncotarget 2018; 7:86388-86405. [PMID: 27835870 PMCID: PMC5349921 DOI: 10.18632/oncotarget.13199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 04/28/2016] [Accepted: 10/29/2016] [Indexed: 12/20/2022] Open
Abstract
Glioblastoma multiforme (GBM) is one of the most lethal solid tumors in adults. Despite aggressive treatment approaches for patients, GBM recurrence is inevitable, in part due to the existence of stem-like brain tumor-propagating cells (BTPCs), which produce factors rendering them resistant to radio- and chemotherapy. Comparative transcriptome analysis of irradiated, patient-derived BTPCs revealed a significant upregulation of the interferon-inducible transmembrane protein 3 (IFITM3), suggesting the protein as a factor mediating radio resistance. Previously, IFITM3 has been described to affect glioma cells; therefore, the role of IFITM3 in the formation and progression of brain tumors has been investigated in vivo. Intracranial implantation studies using radio-selected BTPCs alongside non-irradiated parental BTPCs in immunodeficient mice displayed no influence of irradiation on animal survival. Furthermore, gain and loss of function studies using BTPCs ectopically expressing IFITM3 or having IFITM3 down-modulated by a shRNA approach, did affect neither tumor growth nor animal survival. Additionally, a syngeneic model based on the mouse glioma cell line GL261 was applied in order to consider the possibility that IFITM3 relies on an intact immune system to unfold its tumorigenic potential. GL261 cells ectopically expressing IFITM3 were implanted into the striatum of immunocompetent mice without influencing the survival of glioma-bearing animals. Lastly, the vasculature and the extent of microglia/macrophage invasion into the tumor were studied in BTPC and GL261 tumors but neither parameter was altered by IFITM3. This report presents for the first time that IFITM3 is upregulated in patient-derived BTPCs upon irradiation but does not affect brain tumor formation or progression in vivo.
Collapse
Affiliation(s)
- Nevenka Dudvarski Stankovic
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, Mainz, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nicola Hoppmann
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Research Center for Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Marcin Teodorczyk
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Ella L Kim
- Translational Oncology Research Group, Department of Neurosurgery, Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Matthias Bros
- Department of Dermatology, Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Alf Giese
- Translational Oncology Research Group, Department of Neurosurgery, Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Research Center for Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, Mainz, Germany
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, Mainz, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
18
|
Abstract
Epidermal growth factor receptor (EGFR) and the mutant EGFRvIII are major focal points in current concepts of targeted cancer therapy for glioblastoma multiforme (GBM), the most malignant primary brain tumor. The receptors participate in the key processes of tumor cell invasion and tumor-related angiogenesis and their upregulation correlates with the poor prognosis of glioma patients. Glioma cell invasion and increased angiogenesis share mechanisms of the degradation of the extracellular matrix (ECM) through upregulation of ECM-degrading proteases as well as the activation of aberrant signaling pathways. This review describes the role of EGFR and EGFRvIII in those mechanisms which might offer new combined therapeutic approaches targeting EGFR or EGFRvIII together with drug treatments against proteases of the ECM or downstream signaling to increase the inhibitory effects of mono-therapies.
Collapse
Affiliation(s)
- Stefanie Keller
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Mainz Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, 55131 Mainz, Germany.
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Mainz Neuroscience Network (rmn2), Johannes Gutenberg University, School of Medicine, 55131 Mainz, Germany.
- German Cancer Consortium (DKTK), partner site Frankfurt/Mainz, 55131 Mainz, Germany.
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
| |
Collapse
|
19
|
Vasic V, Schmidt MHH. Resilience and Vulnerability to Pain and Inflammation in the Hippocampus. Int J Mol Sci 2017; 18:ijms18040739. [PMID: 28362320 PMCID: PMC5412324 DOI: 10.3390/ijms18040739] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [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: 02/20/2017] [Revised: 03/17/2017] [Accepted: 03/27/2017] [Indexed: 02/07/2023] Open
Abstract
Increasing evidence demonstrates the importance of hippocampal neurogenesis, a fundamental mechanism of neuroplasticity associated with cognition and emotion, in correlation to neurodegenerative and psychiatric disorders. Neuropsychiatric disorders are often a result of chronic stress or pain followed by inflammation; all these conditions manifest cognitive deficits and impairments in neurogenesis. However, while some individuals are more susceptible to stress, others are able to adapt to new environments via mechanisms of resilience. In light of this emerging field and based on extensive research, the role of neurogenesis is summarized and presented as a potentially powerful therapeutic tool.
Collapse
Affiliation(s)
- Verica Vasic
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), Johannes Gutenberg University, School of Medicine, Mainz 55131, Germany.
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), Johannes Gutenberg University, School of Medicine, Mainz 55131, Germany.
| |
Collapse
|
20
|
Altmann C, Vasic V, Hardt S, Heidler J, Häussler A, Wittig I, Schmidt MHH, Tegeder I. Progranulin promotes peripheral nerve regeneration and reinnervation: role of notch signaling. Mol Neurodegener 2016; 11:69. [PMID: 27770818 PMCID: PMC5075406 DOI: 10.1186/s13024-016-0132-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [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: 02/09/2016] [Accepted: 09/28/2016] [Indexed: 01/11/2023] Open
Abstract
Background Peripheral nerve injury is a frequent cause of lasting motor deficits and chronic pain. Although peripheral nerves are capable of regrowth they often fail to re-innervate target tissues. Results Using newly generated transgenic mice with inducible neuronal progranulin overexpression we show that progranulin accelerates axonal regrowth, restoration of neuromuscular synapses and recovery of sensory and motor functions after injury of the sciatic nerve. Oppositely, progranulin deficient mice have long-lasting deficits in motor function tests after nerve injury due to enhanced losses of motor neurons and stronger microglia activation in the ventral horn of the spinal cord. Deep proteome and gene ontology (GO) enrichment analysis revealed that the proteins upregulated in progranulin overexpressing mice were involved in ‘regulation of transcription’ and ‘response to insulin’ (GO terms). Transcription factor prediction pointed to activation of Notch signaling and indeed, co-immunoprecipitation studies revealed that progranulin bound to the extracellular domain of Notch receptors, and this was functionally associated with higher expression of Notch target genes in the dorsal root ganglia of transgenic mice with neuronal progranulin overexpression. Functionally, these transgenic mice recovered normal gait and running, which was not achieved by controls and was stronger impaired in progranulin deficient mice. Conclusion We infer that progranulin activates Notch signaling pathways, enhancing thereby the regenerative capacity of partially injured neurons, which leads to improved motor function recovery. Graphical abstract ![]()
Electronic supplementary material The online version of this article (doi:10.1186/s13024-016-0132-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Christine Altmann
- Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt, Germany
| | - Verica Vasic
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Stefanie Hardt
- Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt, Germany
| | - Juliana Heidler
- Functional Proteomics, SFB815 Core Unit, Goethe-University, Frankfurt, Germany
| | - Annett Häussler
- Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt, Germany
| | - Ilka Wittig
- Functional Proteomics, SFB815 Core Unit, Goethe-University, Frankfurt, Germany
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Hospital, Frankfurt, Germany.
| |
Collapse
|
21
|
Dudvarski Stankovic N, Teodorczyk M, Ploen R, Zipp F, Schmidt MHH. Microglia-blood vessel interactions: a double-edged sword in brain pathologies. Acta Neuropathol 2016; 131:347-63. [PMID: 26711460 DOI: 10.1007/s00401-015-1524-y] [Citation(s) in RCA: 189] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/09/2015] [Accepted: 12/12/2015] [Indexed: 12/12/2022]
Abstract
Microglia are long-living resident immune cells of the brain, which secure a stable chemical and physical microenvironment necessary for the proper functioning of the central nervous system (CNS). These highly dynamic cells continuously scan their environment for pathogens and possess the ability to react to damage-induced signals in order to protect the brain. Microglia, together with endothelial cells (ECs), pericytes and astrocytes, form the functional blood-brain barrier (BBB), a specialized endothelial structure that selectively separates the sensitive brain parenchyma from blood circulation. Microglia are in bidirectional and permanent communication with ECs and their perivascular localization enables them to survey the influx of blood-borne components into the CNS. Furthermore, they may stimulate the opening of the BBB, extravasation of leukocytes and angiogenesis. However, microglia functioning requires tight control as their dysregulation is implicated in the initiation and progression of numerous neurological diseases. Disruption of the BBB, changes in blood flow, introduction of pathogens in the sensitive CNS niche, insufficient nutrient supply, and abnormal secretion of cytokines or expression of endothelial receptors are reported to prime and attract microglia. Such reactive microglia have been reported to even escalate the damage of the brain parenchyma as is the case in ischemic injuries, brain tumors, multiple sclerosis, Alzheimer's and Parkinson's disease. In this review, we present the current state of the art of the causes and mechanisms of pathological interactions between microglia and blood vessels and explore the possibilities of targeting those dysfunctional interactions for the development of future therapeutics.
Collapse
Affiliation(s)
- Nevenka Dudvarski Stankovic
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University, Langenbeckstr. 1, 55131, Mainz, Germany.
- German Cancer Consortium (DKTK), Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Marcin Teodorczyk
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University, Langenbeckstr. 1, 55131, Mainz, Germany.
| | - Robert Ploen
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Research Center for Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Research Center for Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University, Mainz, Germany.
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University, Langenbeckstr. 1, 55131, Mainz, Germany.
- German Cancer Consortium (DKTK), Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
| |
Collapse
|
22
|
Jolivel V, Bicker F, Binamé F, Ploen R, Keller S, Gollan R, Jurek B, Birkenstock J, Poisa-Beiro L, Bruttger J, Opitz V, Thal SC, Waisman A, Bäuerle T, Schäfer MK, Zipp F, Schmidt MHH. Perivascular microglia promote blood vessel disintegration in the ischemic penumbra. Acta Neuropathol 2015; 129:279-95. [PMID: 25500713 DOI: 10.1007/s00401-014-1372-1] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 12/01/2014] [Accepted: 12/01/2014] [Indexed: 12/11/2022]
Abstract
The contribution of microglia to ischemic cortical stroke is of particular therapeutic interest because of the impact on the survival of brain tissue in the ischemic penumbra, a region that is potentially salvable upon a brain infarct. Whether or not tissue in the penumbra survives critically depends on blood flow and vessel perfusion. To study the role of microglia in cortical stroke and blood vessel stability, CX3CR1(+/GFP) mice were subjected to transient middle cerebral artery occlusion and then microglia were investigated using time-lapse two-photon microscopy in vivo. Soon after reperfusion, microglia became activated in the stroke penumbra and started to expand cellular protrusions towards adjacent blood vessels. All microglia in the penumbra were found associated with blood vessels within 24 h post reperfusion and partially fully engulfed them. In the same time frame blood vessels became permissive for blood serum components. Migration assays in vitro showed that blood serum proteins leaking into the tissue provided molecular cues leading to the recruitment of microglia to blood vessels and to their activation. Subsequently, these perivascular microglia started to eat up endothelial cells by phagocytosis, which caused an activation of the local endothelium and contributed to the disintegration of blood vessels with an eventual break down of the blood brain barrier. Loss-of-microglia-function studies using CX3CR1(GFP/GFP) mice displayed a decrease in stroke size and a reduction in the extravasation of contrast agent into the brain penumbra as measured by MRI. Potentially, medication directed at inhibiting microglia activation within the first day after stroke could stabilize blood vessels in the penumbra, increase blood flow, and serve as a valuable treatment for patients suffering from ischemic stroke.
Collapse
Affiliation(s)
- Valérie Jolivel
- Department of Neurology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University, University Medical Center, Mainz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Notch receptors play an essential role in the regulation of central cellular processes during embryonic and postnatal development. The mammalian genome encodes for four Notch paralogs (Notch 1–4), which are activated by three Delta-like (Dll1/3/4) and two Serrate-like (Jagged1/2) ligands. Further, non-canonical Notch ligands such as epidermal growth factor like protein 7 (EGFL7) have been identified and serve mostly as antagonists of Notch signaling. The Notch pathway prevents neuronal differentiation in the central nervous system by driving neural stem cell maintenance and commitment of neural progenitor cells into the glial lineage. Notch is therefore often implicated in the development of brain tumors, as tumor cells share various characteristics with neural stem and progenitor cells. Notch receptors are overexpressed in gliomas and their oncogenicity has been confirmed by gain- and loss-of-function studies in vitro and in vivo. To this end, special attention is paid to the impact of Notch signaling on stem-like brain tumor-propagating cells as these cells contribute to growth, survival, invasion, and recurrence of brain tumors. Based on the outcome of ongoing studies in vivo, Notch-directed therapies such as γ-secretase inhibitors and blocking antibodies have entered and completed various clinical trials. This review summarizes the current knowledge on Notch signaling in brain tumor formation and therapy.
Collapse
Affiliation(s)
- Marcin Teodorczyk
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University of Mainz School of Medicine , Mainz , Germany
| | - Mirko H H Schmidt
- Molecular Signal Transduction Laboratories, Institute for Microscopic Anatomy and Neurobiology, Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn2), Johannes Gutenberg University of Mainz School of Medicine , Mainz , Germany
| |
Collapse
|
24
|
Fassl A, Tagscherer KE, Richter J, Berriel Diaz M, Alcantara Llaguno SR, Campos B, Kopitz J, Herold-Mende C, Herzig S, Schmidt MHH, Parada LF, Wiestler OD, Roth W. Notch1 signaling promotes survival of glioblastoma cells via EGFR-mediated induction of anti-apoptotic Mcl-1. Oncogene 2012; 31:4698-708. [PMID: 22249262 DOI: 10.1038/onc.2011.615] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The Notch1-mediated signaling pathway has a central role in the maintenance of neural stem cells and contributes to growth and progression of glioblastomas, the most frequent malignant brain tumors in adults. Here, we demonstrate that the Notch1 receptor promotes survival of glioblastoma cells by regulation of the anti-apoptotic Mcl-1 protein. Notch1-dependent regulation of Mcl-1 occurs cell type dependent at a transcriptional or post-translational level and is mediated by the induction of epidermal growth factor receptor (EGFR). Inhibition of the Notch1 pathway overcomes apoptosis resistance and sensitizes glioblastoma cells to apoptosis induced by ionizing radiation, the death ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) or the Bcl-2/Bcl-XL inhibitor ABT-737. In conclusion, targeting Notch1 might represent a promising novel strategy in the treatment of glioblastomas.
Collapse
Affiliation(s)
- A Fassl
- Molecular Tumor Pathology, DKFZ, Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Guarani V, Deflorian G, Franco CA, Krüger M, Phng LK, Bentley K, Toussaint L, Dequiedt F, Mostoslavsky R, Schmidt MHH, Zimmermann B, Brandes RP, Mione M, Westphal CH, Braun T, Zeiher AM, Gerhardt H, Dimmeler S, Potente M. Acetylation-dependent regulation of endothelial Notch signalling by the SIRT1 deacetylase. Nature 2011; 473:234-8. [PMID: 21499261 DOI: 10.1038/nature09917] [Citation(s) in RCA: 282] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 02/10/2011] [Indexed: 01/04/2023]
Abstract
Notch signalling is a key intercellular communication mechanism that is essential for cell specification and tissue patterning, and which coordinates critical steps of blood vessel growth. Although subtle alterations in Notch activity suffice to elicit profound differences in endothelial behaviour and blood vessel formation, little is known about the regulation and adaptation of endothelial Notch responses. Here we report that the NAD(+)-dependent deacetylase SIRT1 acts as an intrinsic negative modulator of Notch signalling in endothelial cells. We show that acetylation of the Notch1 intracellular domain (NICD) on conserved lysines controls the amplitude and duration of Notch responses by altering NICD protein turnover. SIRT1 associates with NICD and functions as a NICD deacetylase, which opposes the acetylation-induced NICD stabilization. Consequently, endothelial cells lacking SIRT1 activity are sensitized to Notch signalling, resulting in impaired growth, sprout elongation and enhanced Notch target gene expression in response to DLL4 stimulation, thereby promoting a non-sprouting, stalk-cell-like phenotype. In vivo, inactivation of Sirt1 in zebrafish and mice causes reduced vascular branching and density as a consequence of enhanced Notch signalling. Our findings identify reversible acetylation of the NICD as a molecular mechanism to adapt the dynamics of Notch signalling, and indicate that SIRT1 acts as rheostat to fine-tune endothelial Notch responses.
Collapse
Affiliation(s)
- Virginia Guarani
- Institute for Cardiovascular Regeneration, Centre of Molecular Medicine, Goethe University, D-60590 Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
EGFL7 drives the formation of neurons from neural stem cells. In the embryonic and adult brain this process is essential for neurogenesis and homeostasis of the nervous system. The function of adult neurogenesis is not fully understood but maybe it supports life-long learning and brain repair after injuries such as stroke. The transition of neural stem cells into mature neurons is tightly regulated. One of the essential signaling pathways governing this process is the Notch pathway, which controls metazoan development. In a recent publication, we identified a novel non-canonical Notch ligand, EGFL7, and described its impact on neural stem cells. We explored the molecular mechanisms, which this molecule affects to regulate the self-renewal capacity of neural stem cells and to promote their differentiation into neurons. In this review, we discuss the implications of our findings for adult neurogenesis and illustrate the potential of EGFL7 to serve as an agent to increase neurogenesis and the self-renewal potential of the brain
Collapse
Affiliation(s)
- Frank Bicker
- Molecular Signal Transduction; Institute of Neurology (Edinger Institute), Johann Wolfgang Goethe University School of Medicine, Frankfurt am Main, Germany
| | | |
Collapse
|
27
|
Abstract
Cancer progression is characterized by autarky in growth signals, insensitivity to growth-restrictive signals, evasion of apoptosis, a limitless potential to replicate, sustained angiogenesis, and tissue invasion, including metastasis. The regulation of these cellular processes relies on a fine-tuned control of molecular signal cascades. In recent years, short noncoding RNAs termed microRNAs (miRNAs) have been described as a novel class of molecular regulators. These affect various signaling cascades during the progression of neoplastic diseases by the regulation of gene expression on the post-transcriptional level. The novel endothelial cell–derived secreted protein epidermal growth factor–like domain 7 (EGFL7) has been suggested to control vascular tubulogenesis. Further, the two biologically active miRNAs miR-126 and its complement miR-126*, which are encoded by intron 7 of the egfl7 gene, have been described to mediate vascular functions. Knock-out studies in zebrafish and mice suggested a major role of miR-126 in angiogenesis and vascular integrity, which was mediated by the repression of inhibitors of VEGF-induced proliferation in endothelial cells. Recent studies revealed the distribution and function of miR-126 and miR-126* in various types of cancer, and assigned a role to both miRNAs as suppressors of tumor formation. Indeed, miR-126 and miR-126* have been reported to impair cancer progression through signaling pathways that control tumor cell proliferation, migration, invasion, and survival. Conversely, miR-126 and miR-126* may have a supportive role in the progression of cancer as well, which might be mediated by the promotion of blood vessel growth and inflammation. In this work, we will summarize the current knowledge on functions of miR-126/miR-126* that are relevant for cancer formation, and we will discuss their potential clinical use as predictive markers of survival and application as novel therapeutic targets for the treatment of neoplastic diseases.
Collapse
Affiliation(s)
- Jeannette Meister
- Molecular Signal Transduction, Institute of Neurology (Edinger Institute), Johann Wolfgang Goethe University School of Medicine, Frankfurt am Main, Germany.
| | | |
Collapse
|
28
|
Abstract
Soluble components of Notch signalling can be applied to manipulate a central pathway essential for the development of metazoans and often deregulated in illnesses such as stroke, cancer or cardiovascular diseases. Commonly, the Notch cascade is inhibited by small compound inhibitors, which either block the proteolysis of Notch receptors by gamma-secretases or interfere with the transcriptional activity of the Notch intracellular domain. Specific antibodies can also be used to inhibit ligand-induced activation of Notch receptors. Alternatively, naturally occurring endogenous inhibitors of Notch signalling might offer a specific way to block receptor activation. Examples are the soluble variants of the canonical Notch ligand Jagged1 and the non-canonical Notch ligand Dlk1, both deprived of their transmembrane regions upon ectodomain shedding, or the bona fide secreted molecule EGFL7. We present frequently used methods to decrease Notch signalling, and we discuss how soluble Notch inhibitors may be used to treat diseases.
Collapse
Affiliation(s)
- Ivan Dikic
- Frankfurt Institute for Molecular Life Sciences (FMLS) and Institute of Biochemistry II, Johann Wolfgang Goethe University School of Medicine, Frankfurt am Main, Germany
| | - Mirko H H Schmidt
- Molecular Signal Transduction, Institute of Neurology (Edinger Institute), Johann Wolfgang Goethe University School of Medicine, Frankfurt am Main, Germany
| |
Collapse
|
29
|
Shimokawa N, Haglund K, Hölter SM, Grabbe C, Kirkin V, Koibuchi N, Schultz C, Rozman J, Hoeller D, Qiu CH, Londoño MB, Ikezawa J, Jedlicka P, Stein B, Schwarzacher SW, Wolfer DP, Ehrhardt N, Heuchel R, Nezis I, Brech A, Schmidt MHH, Fuchs H, Gailus-Durner V, Klingenspor M, Bogler O, Wurst W, Deller T, de Angelis MH, Dikic I. CIN85 regulates dopamine receptor endocytosis and governs behaviour in mice. EMBO J 2010; 29:2421-32. [PMID: 20551902 DOI: 10.1038/emboj.2010.120] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2009] [Accepted: 05/17/2010] [Indexed: 01/17/2023] Open
Abstract
Despite extensive investigations of Cbl-interacting protein of 85 kDa (CIN85) in receptor trafficking and cytoskeletal dynamics, little is known about its functions in vivo. Here, we report the study of a mouse deficient of the two CIN85 isoforms expressed in the central nervous system, exposing a function of CIN85 in dopamine receptor endocytosis. Mice lacking CIN85 exon 2 (CIN85(Deltaex2)) show hyperactivity phenotypes, characterized by increased physical activity and exploratory behaviour. Interestingly, CIN85(Deltaex2) animals display abnormally high levels of dopamine and D2 dopamine receptors (D2DRs) in the striatum, an important centre for the coordination of animal behaviour. Importantly, CIN85 localizes to the post-synaptic compartment of striatal neurons in which it co-clusters with D2DRs. Moreover, it interacts with endocytic regulators such as dynamin and endophilins in the striatum. Absence of striatal CIN85 causes insufficient complex formation of endophilins with D2DRs in the striatum and ultimately decreased D2DR endocytosis in striatal neurons in response to dopamine stimulation. These findings indicate an important function of CIN85 in the regulation of dopamine receptor functions and provide a molecular explanation for the hyperactive behaviour of CIN85(Deltaex2) mice.
Collapse
Affiliation(s)
- Noriaki Shimokawa
- Institute of Biochemistry II and Cluster of Excellence Macromolecular Complexes, Goethe University, Frankfurt (Main), Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Blood vessels form de novo through the tightly regulated programs of vasculogenesis and angiogenesis. Both processes are distinct but one of the steps they share is the formation of a central lumen, when groups of cells organized as vascular cords undergo complex changes to achieve a tube-like morphology. Recently, a protein termed epidermal growth factor-like domain 7 (EGFL7) was described as a novel endothelial cell-derived factor involved in the regulation of the spatial arrangement of cells during vascular tube assembly. With its impact on tubulogenesis and vessel shape EGFL7 joined the large family of molecules governing blood vessel formation. Only recently, the molecular mechanisms underlying EGFL7's effects have been started to be elucidated and shaping of the extracellular matrix (ECM) as well as Notch signaling might very well play a role in mediating its biological effects. Further, findings in knock-out animal models suggest miR-126, a miRNA located within the egfl7 gene, has a major role in vessel development by promoting VEGF signaling, angiogenesis and vascular integrity. This review summarizes our current knowledge on EGFL7 and miR-126 and we will discuss the implications of both bioactive molecules for the formation of blood vessels.
Collapse
Affiliation(s)
- Iva Nikolic
- Institute of Neurology (Edinger Institute), Johann Wolfgang Goethe University School of Medicine, Heinrich-Hoffmann-Str, 7, Frankfurt am Main, D-60528, Germany.
| | | | | |
Collapse
|
31
|
Schneider FT, Schänzer A, Czupalla CJ, Thom S, Engels K, Schmidt MHH, Plate KH, Liebner S. Sonic hedgehog acts as a negative regulator of {beta}-catenin signaling in the adult tongue epithelium. Am J Pathol 2010; 177:404-14. [PMID: 20508033 DOI: 10.2353/ajpath.2010.091079] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Wnt/beta-catenin signaling has been implicated in taste papilla development; however, its role in epithelial maintenance and tumor progression in the adult tongue remains elusive. We show Wnt/beta-catenin pathway activation in reporter mice and by nuclear beta-catenin staining in the epithelium and taste papilla of adult mouse and human tongues. beta-Catenin activation in APC(min/+) mice, which carry a mutation in adenomatous poliposis coli (APC), up-regulates Sonic hedgehog (Shh) and Jagged-2 (JAG2) in the tongue epithelium without formation of squamous cell carcinoma (SCC). We demonstrate that Shh suppresses beta-catenin transcriptional activity in a signaling-dependent manner in vitro and in vivo. A similar regulation and function was observed for JAG2, suggesting that both pathways negatively regulate beta-catenin, thereby preventing SCC formation in the tongue. This was supported by reduced nuclear beta-catenin in the tongue epithelium of Patched(+/-) mice, exhibiting dominant active Shh signaling. At the invasive front of human tongue cancer, nuclear beta-catenin and Shh were increased, suggesting their participation in tumor progression. Interestingly, Shh but not JAG2 was able to reduce beta-catenin signaling in SCC cells, arguing for a partial loss of negative feedback on beta-catenin transcription in tongue cancer. We show for the first time that the putative Wnt/beta-catenin targets Shh and JAG2 control beta-catenin signaling in the adult tongue epithelium, a function that is partially lost in lingual SCC.
Collapse
Affiliation(s)
- Fabian T Schneider
- Institute of Neurology (Edinger-Institute), Johann Wolfgang Goethe-University Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Deribe YL, Wild P, Chandrashaker A, Curak J, Schmidt MHH, Kalaidzidis Y, Milutinovic N, Kratchmarova I, Buerkle L, Fetchko MJ, Schmidt P, Kittanakom S, Brown KR, Jurisica I, Blagoev B, Zerial M, Stagljar I, Dikic I. Regulation of epidermal growth factor receptor trafficking by lysine deacetylase HDAC6. Sci Signal 2009; 2:ra84. [PMID: 20029029 DOI: 10.1126/scisignal.2000576] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Binding of epidermal growth factor (EGF) to its receptor leads to receptor dimerization, assembly of protein complexes, and activation of signaling networks that control key cellular responses. Despite their fundamental role in cell biology, little is known about protein complexes associated with the EGF receptor (EGFR) before growth factor stimulation. We used a modified membrane yeast two-hybrid system together with bioinformatics to identify 87 candidate proteins interacting with the ligand-unoccupied EGFR. Among them was histone deacetylase 6 (HDAC6), a cytoplasmic lysine deacetylase, which we found negatively regulated EGFR endocytosis and degradation by controlling the acetylation status of alpha-tubulin and, subsequently, receptor trafficking along microtubules. A negative feedback loop consisting of EGFR-mediated phosphorylation of HDAC6 Tyr(570) resulted in reduced deacetylase activity and increased acetylation of alpha-tubulin. This study illustrates the complexity of the EGFR-associated interactome and identifies protein acetylation as a previously unknown regulator of receptor endocytosis and degradation.
Collapse
Affiliation(s)
- Yonathan Lissanu Deribe
- Institute of Biochemistry II and Cluster of Excellence Macromolecular Complexes, Goethe University School of Medicine, Frankfurt (Main), Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Schmidt MHH, Bicker F, Nikolic I, Meister J, Babuke T, Picuric S, Müller-Esterl W, Plate KH, Dikic I. Epidermal growth factor-like domain 7 (EGFL7) modulates Notch signalling and affects neural stem cell renewal. Nat Cell Biol 2009; 11:873-80. [PMID: 19503073 DOI: 10.1038/ncb1896] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 03/13/2009] [Indexed: 01/08/2023]
Abstract
Epidermal growth factor-like domain 7 (EGFL7) is a secreted factor implicated in cellular responses such as cell migration and blood vessel formation; however the molecular mechanisms underlying the effects of EGFL7 are largely unknown. Here we have identified transmembrane receptors of the Notch family as EGFL7-binding molecules. Secreted EGFL7 binds to a region in Notch involved in ligand-mediated receptor activation, thus acting as an antagonist of Notch signalling. Expression of EGFL7 in neural stem cells (NSCs) in vitro decreased Notch-specific signalling and consequently, reduced proliferation and self-renewal of NSCs. Such altered Notch signalling caused a shift in the differentiation pattern of cultured NSCs towards an excess of neurons and oligodendrocytes. We identified neurons as a source of EGFL7 in the brain, suggesting that brain-derived EGFL7 acts as an endogenous antagonist of Notch signalling that regulates proliferation and differentiation of subventricular zone-derived adult NSCs.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Institute of Biochemistry II, Johann Wolfgang Goethe University School of Medicine, Frankfurt am Main, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Reiss Y, Knedla A, Tal AO, Schmidt MHH, Jugold M, Kiessling F, Burger AM, Wolburg H, Deutsch U, Plate KH. Switching of vascular phenotypes within a murine breast cancer model induced by angiopoietin-2. J Pathol 2009; 217:571-80. [PMID: 19116989 DOI: 10.1002/path.2484] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Sustained growth of solid tumours can rely on both the formation of new and the co-option of existing blood vessels. Current models suggest that binding of angiopoietin-2 (Ang-2) to its endothelial Tie2 receptor prevents receptor phosphorylation, destabilizes blood vessels, and promotes vascular permeability. In contrast, binding of angiopoietin-1 (Ang-1) induces Tie2 receptor activation and supports the formation of mature blood vessels covered by pericytes. Despite the intense research to decipher the role of angiopoietins during physiological neovascularization and tumour angiogenesis, a mechanistic understanding of angiopoietin function on vascular integrity and remodelling is still incomplete. We therefore assessed the vascular morphology of two mouse mammary carcinoma xenotransplants (M6378 and M6363) which differ in their natural angiopoietin expression. M6378 displayed Ang-1 in tumour cells but no Ang-2 in tumour endothelial cells in vivo. In contrast, M6363 tumours expressed Ang-2 in the tumour vasculature, whereas no Ang-1 expression was present in tumour cells. We stably transfected M6378 mouse mammary carcinoma cells with human Ang-1 or Ang-2 and investigated the consequences on the host vasculature, including ultrastructural morphology. Interestingly, M6378/Ang-2 and M6363 tumours displayed a similar vascular morphology, with intratumoural haemorrhage and non-functional and abnormal blood vessels. Pericyte loss was prominent in these tumours and was accompanied by increased endothelial cell apoptosis. Thus, overexpression of Ang-2 converted the vascular phenotype of M6378 tumours into a phenotype similar to M6363 tumours. Our results support the hypothesis that Ang-1/Tie2 signalling is essential for vessel stabilization and endothelial cell/pericyte interaction, and suggest that Ang-2 is able to induce a switch of vascular phenotypes within tumours.
Collapse
Affiliation(s)
- Yvonne Reiss
- Institute of Neurology/Edinger Institute, Frankfurt University Medical School, Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Nonis D, Schmidt MHH, van de Loo S, Eich F, Dikic I, Nowock J, Auburger G. Ataxin-2 associates with the endocytosis complex and affects EGF receptor trafficking. Cell Signal 2008; 20:1725-39. [PMID: 18602463 DOI: 10.1016/j.cellsig.2008.05.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/16/2008] [Accepted: 05/21/2008] [Indexed: 12/13/2022]
Abstract
Ataxin-2 is a novel protein, where the unstable expansion of an internal polyglutamine domain can cause the neurodegenerative disease Spinocerebellar Ataxia type 2 (SCA2). To elucidate its cellular function, we have used full-length ataxin-2 as bait in a yeast two-hybrid screen of human adult brain cDNA. As binding partners we found endophilin A1 and A3, two brain-expressed members of the endophilin A family involved in synaptic vesicle endocytosis. Co-immunoprecipitation studies confirmed the binding of these proteins as an endogenous complex in mouse brain. In vitro binding experiments narrowed the binding interfaces down to two proline-rich domains on ataxin-2, which interacted with the SH3 domain of endophilin A1/A3. Ataxin-2 and endophilin associated at the endoplasmic reticulum as well as at the plasma membrane as determined by immunofluorescence microscopy of transfected cell lines, and by centrifugation fractionation studies of mouse brain. Importantly, the pattern observed in transfected cells was conserved in rat hippocampal neurons. In the mouse brain, an association of ataxin-2 with endocytic proteins such as the adaptor CIN85 and the ubiquitin ligase c-Cbl was also demonstrated. GST pull-down assays showed ataxin-2 to directly interact with the SH3 domains A and C of CIN85 and with the SH3 domain of Src, a kinase activated after receptor stimulation. Functional studies demonstrated that ataxin-2 affects endocytic trafficking of the epidermal growth factor receptor (EGFR). Taken together, these data implicate ataxin-2 to play a role in endocytic receptor cycling.
Collapse
Affiliation(s)
- David Nonis
- Department of Neurology, J. W. Goethe University Medical School, Frankfurt/M, Germany
| | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Cbl proteins are ubiquitin ligases and multifunctional adaptor proteins that are implicated in the regulation of signal transduction in various cell types and in response to different stimuli. Cbl-associated proteins can assemble together at a given time or space inside the cell, and such an interactome can form signal competent networks that control many physiological processes. Dysregulation of spatial or temporal constraints in the Cbl interactome results in the development of human pathologies such as immune diseases, diabetes and cancer.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Institute for Biochemistry II, Goethe University Medical School, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | | |
Collapse
|
37
|
Sargin B, Choudhary C, Crosetto N, Schmidt MHH, Grundler R, Rensinghoff M, Thiessen C, Tickenbrock L, Schwäble J, Brandts C, August B, Koschmieder S, Bandi SR, Duyster J, Berdel WE, Müller-Tidow C, Dikic I, Serve H. Flt3-dependent transformation by inactivating c-Cbl mutations in AML. Blood 2007; 110:1004-12. [PMID: 17446348 DOI: 10.1182/blood-2007-01-066076] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [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: 01/19/2023] Open
Abstract
Abstract
In acute myeloid leukemia (AML), mutational activation of the receptor tyrosine kinase (RTK) Flt3 is frequently involved in leukemic transformation. However, little is known about a possible role of highly expressed wild-type Flt3 in AML. The proto-oncogene c-Cbl is an important regulator of RTK signaling, acting through its ubiquitin ligase activity and as a platform for several signaling adaptor molecules. Here, we analyzed the role of c-Cbl in Flt3 signal transduction and myeloid transformation. C-Cbl physically interacted with Flt3 and was tyrosine phosphorylated in the presence of Flt3-ligand (FL). Overexpression of a dominant-negative form of c-Cbl (Cbl-70Z) inhibited FL-induced Flt3 ubiquitylation and internalization, indicating involvement of c-Cbl in Flt3 signaling. DNA sequencing of AML bone marrow revealed a case with a c-Cbl point mutation (Cbl-R420Q). Cbl-R420Q inhibited Flt3 internalization and ubiquitylation. Coexpression of Cbl-R420Q or Cbl-70Z with Flt3 induced cytokine-independent growth and survival of 32Dcl3 cells in the absence of FL. Also, the mutant Cbl proteins altered the amplitude and duration of Flt3-dependent signaling events. Our results indicate an important role of Cbl proteins in Flt3 signal modulation. Also, the data suggest a novel mechanism of leukemic transformation in AML by mutational inactivation of negative RTK regulators.
Collapse
MESH Headings
- Animals
- Bone Marrow/metabolism
- Bone Marrow/pathology
- COS Cells
- Cell Survival
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Chlorocebus aethiops
- Gene Expression Regulation, Leukemic
- Genes, Dominant
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Mice
- Phosphorylation
- Point Mutation
- Protein Binding
- Protein Processing, Post-Translational
- Proto-Oncogene Mas
- Proto-Oncogene Proteins c-cbl/genetics
- Proto-Oncogene Proteins c-cbl/metabolism
- Signal Transduction
- fms-Like Tyrosine Kinase 3/genetics
- fms-Like Tyrosine Kinase 3/metabolism
Collapse
Affiliation(s)
- Bülent Sargin
- Department of Medicine, Hematology and Oncology, and Interdisciplinary Center for Clinical Research, University Hospital Münster, Albert-Schweitzer-Strasse 33, 48129 Münster, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Dikic I, Schmidt MHH. Malfunctions within the Cbl interactome uncouple receptor tyrosine kinases from destructive transport. Eur J Cell Biol 2007; 86:505-12. [PMID: 17553592 DOI: 10.1016/j.ejcb.2007.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 04/24/2007] [Accepted: 04/24/2007] [Indexed: 12/14/2022] Open
Abstract
Proteins of the Cbl family are adaptor molecules and ubiquitin ligases with major functions in the regulation, intracellular transport and degradation of receptor tyrosine kinases (RTKs). Due to this central role, mutations that cause malfunctions of Cbl or their associated proteins - termed the Cbl interactome - easily lead to the transformation of affected cells and eventually the development of cancer. This review intends to give an overview on the mechanisms of Cbl-mediated cell transformation in light of the dysregulated intracellular trafficking of RTKs.
Collapse
Affiliation(s)
- Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | | |
Collapse
|
39
|
Abstract
Ubiquitin (Ub) and ubiquitin-like (Ubl) proteins are small signaling molecules that are involved in many aspects of cell function. It has been assumed that Ub and Ubl have functionally distinct roles because they use different conjugation machineries and bind to different effector proteins. This paradigm, however, must be revisited after recent findings that signaling cascades mediated by Ub and the Ubl NEDD8 (Neural precursor cell-Expressed Developmentally Down-regulated 8) in the regulation of epidermal growth factor receptor (EGFR) endocytosis are redundant. In this context, Ub and NEDD8 share the same E3 ligase, Cbl, and are recognized by identical components of the endocytic sorting machinery. This unexpected redundancy introduces additional complexity to the current view of Ub signaling pathways.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Institute of Biochemistry II, Johann Wolfgang Goethe-University School of Medicine, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | | |
Collapse
|
40
|
Abstract
The Pix/Cool proteins are involved in the regulation of cell morphology by binding to small Rho GTPases and kinases of the Pak family. Recently, it has been shown that betaPix/Cool-1 associates with the ubiquitin ligase Cbl, which appears to be a critical step in Cdc42-mediated inhibition of epidermal-growth-factor-receptor (EGFR) ubiquitylation and downregulation. Here we show that the SH3 domain of betaPix specifically interacts with a proline-arginine motif (PxxxPR) present within the ubiquitin ligase Cbl and Pak1 kinase. Owing to targeting of the same sequence, Cbl and Pak1 compete for binding to betaPix. In this complex, Cbl mediates ubiquitylation and subsequent degradation of betaPix. Our findings reveal a double feedback loop in which the Cdc42/betaPix complex blocks Cbl's ability to downregulate EGFR, while Cbl in turn promotes degradation of betaPix in order to escape this inhibition. Such a relationship provides a mechanism to fine-tune the kinetics of RTK endocytosis and degradation depending on the pool of active Cdc42 and the duration of EGFR signaling.
Collapse
Affiliation(s)
- M H H Schmidt
- Institute of Biochemistry II, University Hospital of the Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | | | | | | | | |
Collapse
|
41
|
Abstract
Recently the life cycles of receptor tyrosine kinases (RTKs) have become a focus of signal transduction research. Ligand-induced ubiquitination of RTKs followed by their internalization and degradation has, in particular, been extensively studied. This chapter describes the basic methods used to measure ubiquitination and degradation of RTKs using the example of the epidermal growth factor receptor (EGFR). Common sources for endogenous and recombinant EGFR as well as cell lines used to conduct receptor downregulation assays are described. Monitoring of ubiquitination and degradation of the EGFR subsequent to stimulation with the receptor ligand EGF is described. Finally, protocols to quantitatively measure degradation of the EGFR by pulse chase experiments or using radiolabeled ligands such as 125I-EGF are presented.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Institute for Biochemistry II, Goethe University School of Medicine, Germany
| | | |
Collapse
|
42
|
Haglund K, Schmidt MHH, Wong ESM, Guy GR, Dikic I. Sprouty2 acts at the Cbl/CIN85 interface to inhibit epidermal growth factor receptor downregulation. EMBO Rep 2005; 6:635-41. [PMID: 15962011 PMCID: PMC1369112 DOI: 10.1038/sj.embor.7400453] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Revised: 05/13/2005] [Accepted: 05/17/2005] [Indexed: 11/09/2022] Open
Abstract
The ubiquitin ligase Cbl mediates ubiquitination of activated receptor tyrosine kinases (RTKs) and interacts with endocytic scaffold complexes, including CIN85/endophilins, to facilitate RTK endocytosis and degradation. Several mechanisms regulate the functions of Cbl to ensure the fine-tuning of RTK signalling and cellular homeostasis. One regulatory mechanism involves the binding of Cbl to Sprouty2, which sequesters Cbl away from activated epidermal growth factor receptors (EGFRs). Here, we show that Sprouty2 associates with CIN85 and acts at the interface between Cbl and CIN85 to inhibit EGFR downregulation. The CIN85 SH3 domains A and C bind specifically to proline-arginine motifs present in Sprouty2. Intact association between Sprouty2, Cbl and CIN85 is required for inhibition of EGFR endocytosis as well as EGF-induced differentiation of PC12 cells. Moreover, Sprouty4, which lacks CIN85-binding sites, does not inhibit EGFR downregulation, providing a molecular explanation for functional differences between Sprouty isoforms. Sprouty2 therefore acts as an inducible inhibitor of EGFR downregulation by targeting both the Cbl and CIN85 pathways.
Collapse
Affiliation(s)
- Kaisa Haglund
- Institute for Biochemistry II, Building 75, Goethe University Medical School, Theoder-Stern-Kai 7, 605 90 Frankfurt am Main, Germany
| | - Mirko H H Schmidt
- Institute for Biochemistry II, Building 75, Goethe University Medical School, Theoder-Stern-Kai 7, 605 90 Frankfurt am Main, Germany
| | - Esther Sook Miin Wong
- Signal Transduction Laboratory, Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos 138673, Singapore
| | - Graeme R Guy
- Signal Transduction Laboratory, Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos 138673, Singapore
| | - Ivan Dikic
- Institute for Biochemistry II, Building 75, Goethe University Medical School, Theoder-Stern-Kai 7, 605 90 Frankfurt am Main, Germany
- Tel: +49 69 6301 83647; Fax: +49 69 6301 5577; E-mail:
| |
Collapse
|
43
|
Schmidt MHH, Hoeller D, Yu J, Furnari FB, Cavenee WK, Dikic I, Bögler O. Alix/AIP1 antagonizes epidermal growth factor receptor downregulation by the Cbl-SETA/CIN85 complex. Mol Cell Biol 2004; 24:8981-93. [PMID: 15456872 PMCID: PMC517880 DOI: 10.1128/mcb.24.20.8981-8993.2004] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [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: 11/20/2022] Open
Abstract
The assembly of the Cbl-SETA/CIN85-endophilin complex at the C terminus of the epidermal growth factor receptor (EGFR) following ligand activation mediates its internalization and ubiquitination. We found that the SETA/CIN85-interacting protein Alix/AIP1, which also binds endophilins, modulates this complex. Alix was found to associate indirectly with EGFR, regardless of its activation state, and with DeltaEGFR, which signals at low intensity and does not bind Cbls or SETA/CIN85. In agreement with this, Alix interaction did not occur via SETA/CIN85. However, SETA/CIN85 and Alix were capable of mutually promoting their interaction with the EGFR. Increasing the level of Alix weakened the interaction between SETA/CIN85 and Cbl and reduced the tyrosine phosphorylation of c-Cbl and the level of ubiquitination of EGFR, SETA/CIN85, and Cbls. This antagonism of the Cbl-SETA/CIN85 complex by Alix was reflected in its diminution of EGFR internalization. In agreement with this, small interfering RNA-mediated knockdown of Alix promoted EGFR internalization and downregulation. It has been suggested that SETA/CIN85 promotes receptor internalization by recruiting endophilins. However, Alix was also capable of increasing the level of endophilin associated with EGFR, implying that this is not sufficient to promote receptor internalization. We propose that Alix inhibits EGFR internalization by attenuating the interaction between Cbl and SETA/CIN85 and by inhibiting Cbl-mediated ubiquitination of the EGFR.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- William and Karen Davidson Laboratory of Brain Tumor Biology, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, 2799 West Grand Blvd., Detroit, MI 48202, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
Alix/AIP1 is an adaptor protein involved in regulating the function of receptor and cytoskeleton-associated tyrosine kinases. Here, we investigated its interaction with and regulation by Src. Tyr319 of Alix bound the isolated Src homology-2 (SH2) domain and was necessary for interaction with intact Src. A proline-rich region in the C terminus of Alix bound the Src SH3 domain, but this interaction was dependent on the release of the Src SH2 domain from its Src internal ligand either by interaction with Alix Tyr319 or by mutation of Src Tyr527. Src phosphorylated Alix at a C-terminal region rich in tyrosines, an activity that was stimulated by the presence of the Alix binding partner SETA/CIN85. Phosphorylation of Alix by Src caused it to translocate from the membrane and cytoskeleton to the cytoplasm and reduced its interaction with binding partners SETA/CIN85, epidermal growth factor receptor, and Pyk2. As a consequence of this, Src antagonized the negative regulation of receptor tyrosine kinase internalization and cell adhesion by Alix. We propose a model whereby Src antagonizes the effects of Alix by phosphorylation of its C terminus, leading to the disruption of interactions with target proteins.
Collapse
Affiliation(s)
- Mirko H. H. Schmidt
- From the William and Karen Davidson Laboratory of Brain Tumor Biology, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, Detroit, Michigan 48202 and the
- Institute of Biochemistry II, Goethe University Medical School, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University Medical School, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Oliver Bögler
- From the William and Karen Davidson Laboratory of Brain Tumor Biology, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, Detroit, Michigan 48202 and the
- || To whom correspondence should be addressed: Dept. of Neurosurgery, Henry Ford Hospital, E&R 3096, 2799 W. Grand Blvd., Detroit, MI 48202. Tel.: 313-916-7293; Fax: 425-732-8379; E-mail:
| |
Collapse
|
45
|
Schmidt MHH, Broll R, Bruch HP, Finniss S, Bögler O, Duchrow M. Proliferation marker pKi-67 occurs in different isoforms with various cellular effects. J Cell Biochem 2004; 91:1280-92. [PMID: 15048881 DOI: 10.1002/jcb.20016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [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: 12/16/2022]
Abstract
The Ki-67 antigen, pKi-67, is a commonly used proliferation marker in research and pathology. It has been recognized that the protein exists in two different splice variants that differ in one exon. In the current work, we present three new splice variants of human pKi-67 consisting of two naturally occurring isoforms and one atypical version. Additionally, data is presented indicating that alternative splicing of the pKi-67 N-terminus is common in tumor cell lines. Analyzing 93 tissues mainly consisting of brain tumor specimens, we found evidence that long and short isoform can be expressed independently of each other. Induction of mitosis in human peripheral blood mononuclear cells revealed that short pKi-67 appears earlier in the cell cycle than the long isoform and reaches its expression maximum when transcription of the latter sets in. Finally, transfection of mammalian culture cells with exon 7 (specific for the long pKi-67 isoform and not present in the short isoform) in a tetracycline regulated expression system decreased the rate of cell proliferation without affecting the cell cycle. In summary, we present evidence that the pKi-67 N-terminus is differentially spliced resulting in at least five different isoforms with different functions.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- Surgical Research Laboratory, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | | | | | | | | | | |
Collapse
|
46
|
Bubán T, Schmidt MHH, Broll R, Antal-Szalmás P, Duchrow M. Detection of mutations in the cDNA of the proliferation marker Ki-67 protein in four tumor cell lines. ACTA ACUST UNITED AC 2004; 149:81-4. [PMID: 15104289 DOI: 10.1016/s0165-4608(03)00297-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2003] [Accepted: 07/18/2003] [Indexed: 11/20/2022]
Abstract
The Ki-67 protein has an essential role in cell proliferation. It is present in all dividing cells of normal and tumor tissues, but absent in resting cells. At present, no data are available about any alterations in the gene of this protein that could contribute to its altered structure and function, resulting in tumor development. We therefore searched for mutations in the Ki-67 gene (MKI67). cDNAs from four tumor cell lines derived from carcinoma of the cervix (HeLa), colon (CXF94, SW480), and lung (A549) were prepared. Defined parts of the cDNA were amplified by specific primers, cloned into pCRII-Blunt-TOPO vector, and replicated in Escherichia coli. The sequence of the amplified products were determined by automated fluorescence sequencing. Eight different mutations were characterized in the four cell lines tested. One is a deletion of a single base at position 1496 causing a truncated protein, the second is a A433T exchange is a silent mutation, and the remaining six mutations result in an amino acid change that might alter the conformation of the protein. Our results show that several mutations exist within the Ki-67 protein's cDNA in four tumor cell lines. These mutations might provide a genetic basis for tumor development.
Collapse
Affiliation(s)
- Tamás Bubán
- Surgical Research, Department of Surgery, University of Luebeck, Germany.
| | | | | | | | | |
Collapse
|
47
|
Kowanetz K, Husnjak K, Höller D, Kowanetz M, Soubeyran P, Hirsch D, Schmidt MHH, Pavelic K, De Camilli P, Randazzo PA, Dikic I. CIN85 associates with multiple effectors controlling intracellular trafficking of epidermal growth factor receptors. Mol Biol Cell 2004; 15:3155-66. [PMID: 15090612 PMCID: PMC452573 DOI: 10.1091/mbc.e03-09-0683] [Citation(s) in RCA: 105] [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: 12/21/2022] Open
Abstract
CIN85 is a multidomain adaptor protein involved in Cbl-mediated down-regulation of epidermal growth factor (EGF) receptors. CIN85 src homology 3 domains specifically bind to a proline-arginine (PxxxPR) motif in Cbl, and this association seems to be important for EGF receptor endocytosis. Here, we report identification of novel CIN85 effectors, all containing one or more PxxxPR motifs, that are indispensable for their mutual interactions. These effectors include phosphatidyl-inositol phosphatases SHIP-1 and synaptojanin 2B1, Arf GTPase-activating proteins ASAP1 and ARAP3, adaptor proteins Hip1R and STAP1, and a Rho exchange factor, p115Rho GEF. Acting as a molecular scaffold, CIN85 clusters its effectors and recruits them to high-molecular-weight complexes in cytosolic extracts of cells. Further characterization of CIN85 binding to ASAP1 revealed that formation of the complex is independent on cell stimulation. Overexpression of ASAP1 increased EGF receptor recycling, whereas ASAP1 containing mutated PxxxPR motif failed to promote this event. We propose that CIN85 functions as a scaffold molecule that binds to numerous endocytic accessory proteins, thus controlling distinct steps in trafficking of EGF receptors along the endocytic and recycling pathways.
Collapse
Affiliation(s)
- Katarzyna Kowanetz
- Institute of Biochemistry II, Goethe University Medical School, 60590 Frankfurt, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
The proliferation marker pKi-67 is commonly used in research and pathology to detect proliferating cells. In a previous work, we found the protein to be associated with regulators of the cell cycle, controlling S-phase progression, as well as entry into and exit from mitosis. Here we investigate whether pKi-67 has a regulative effect on the cell cycle itself. For that purpose we cloned four fragments of pKi-67, together representing nearly the whole protein, and an N-terminal pKi-67 antisense oligonucleotide into a tetracycline inducible gene expression system. The sense fragments were C-terminally modified by addition of either a nuclear localization sequence (NLS) or a STOP codon to address the impact of their intracellular distribution. FACS based cell cycle analysis revealed that expression of nearly all pKi-67 domains and the antisense oligonucleotide led to a decreased amount of cells in S-phase and an increased number of cells in G(2)/M- and G(1)-phase. Subsequent analysis of the endogenous pKi-67 mRNA and protein levels revealed that the constructs with the most significant impact on the cell cycle were able to silence pKi-67 transcription as well. We conclude from the data that pKi-67 influences progression of S-phase and mitosis in a self-regulated manner and, therefore, effects the cell cycle checkpoints within both phases. Furthermore, we found pKi-67 mediates an anti-apoptotic effect on the cell and we verified that this marker, although it is a potential ribosomal catalyst, is not expressed in differentiated tissues with a high transcriptional activity.
Collapse
|
49
|
Schmidt MHH, Chen B, Randazzo LM, Bogler O. SETA/CIN85/Ruk and its binding partner AIP1 associate with diverse cytoskeletal elements, including FAKs, and modulate cell adhesion. J Cell Sci 2003; 116:2845-55. [PMID: 12771190 DOI: 10.1242/jcs.00522] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [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: 12/25/2022] Open
Abstract
The adaptor protein SETA/CIN85/Ruk is involved in regulating diverse signal transduction pathways, including the internalization of tyrosine kinase receptors via the Cbl ubiquitin ligases, and attenuating PI3K activity by interaction with its regulatory subunit. Here we present evidence for a new aspect of SETA function, based on the initial observation that it co-localizes with actin in microfilaments and at focal adhesions, and with microtubules. Although there was no evidence for direct molecular interactions between SETA and cytoskeletal proteins, the SETA-interacting protein AIP1, which is a rat ortholog of the Xenopus src substrate Xp95, strongly interacted with structural proteins of the cytoskeleton, including actin and tubulins. Both SETA and AIP1 interacted with focal adhesion kinase (FAK) and proline rich tyrosine kinase 2 (PYK-2), and c-Cbl interacted with PYK-2. AIP1, which interacted more strongly than either SETA or c-Cbl, required an intact consensus tyrosine kinase phosphorylation sequence at Y319 to bind to focal adhesion kinases, which suggests that phosphorylation is an important mediator of this complex. SETA, which interacted as a dimer with focal adhesion kinases, promoted the interaction between PYK-2 and AIP1. Direct analysis of the impact of these proteins on cell adhesion, by use of an electrical cell-substrate impedance sensor (ECIS), showed that SETA promoted cell adhesion while AIP1 and c-Cbl reduced it. Furthermore, the ability of AIP1 and AIP1 mutants to decrease cell adhesion in ECIS analysis correlated with their presence in PYK-2 complexes, providing a direct link between AIP1-mediated molecular interactions and cellular behavior. Transfection of AIP1 also reduced the level of phosphorylation of endogenous PYK-2 and FAK, suggesting that this protein may directly regulate focal adhesion kinases, and thereby cell adhesion. These data are the first to implicate the adaptor protein SETA and its binding partner AIP1 as being involved with the cytoskeleton and in the regulation of cell adhesion, and suggest that they may be part of the focal adhesion kinase regulatory complex.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- William and Karen Davidson Laboratory of Brain Tumor Biology, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202, USA
| | | | | | | |
Collapse
|
50
|
Schmidt MHH, Furnari FB, Cavenee WK, Bögler O. Epidermal growth factor receptor signaling intensity determines intracellular protein interactions, ubiquitination, and internalization. Proc Natl Acad Sci U S A 2003; 100:6505-10. [PMID: 12734385 PMCID: PMC164476 DOI: 10.1073/pnas.1031790100] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.9] [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: 11/18/2022] Open
Abstract
Ligand activation of the epidermal growth factor receptor (EGFR) causes the binding of Cbls, which leads to EGFR polyubiquitination and internalization through endophilin complexes that contain the adaptor protein SH3-domain encoding, expressed in tumorigenic astrocytes/Cbl-interacting protein of 85 kDa/regulator of ubiquitous kinase (SETA/CIN85/Ruk). In cells grown at high density, high levels of SETA interfered in the recruitment of Casitas B-lineage (Cbl) proteins to the EGFR and reduced its polyubiquitination, suggesting that SETA has a regulatory function in the formation of the EGFR-Cbl-endophilin complex and in EGFR down-regulation. In a situation where there is EGFR signaling but no internalization or down-regulation, as is the case with the EGFR with exons 2-7 deleted (DeltaEGFR) oncogene, these proteins were absent altogether. By using mAb 806, which recognizes an EGFR-activation state and preferentially immunoprecipitates DeltaEGFR, we show that DeltaEGFR did not interact with Cbls, SETA, or endophilin A1, providing a mechanistic explanation for its lack of internalization. As would be expected by the absence of Cbl proteins in the DeltaEGFR complex, the mutant receptor was also not polyubiquitinated. The intracellular C terminus and tyrosine autophosphorylation pattern of DeltaEGFR are similar to wild-type EGFR, but it signals at a lower intensity as determined by levels of EGFR phosphotyrosine. To test the implication that the lack of interaction with the Cbl-SETA-endophilin complex is because of differences in signal intensity, EGFR-expressing cells were treated with tyrphostin AG1478 EGFR inhibitor. Attenuation of wild-type EGFR signal to levels similar to that found in DeltaEGFR resulted in the dissociation of SETA and Cbl proteins and a concomitant attenuation of receptor internalization.
Collapse
Affiliation(s)
- Mirko H H Schmidt
- William and Karen Davidson Laboratory of Brain Tumor Biology, Hermelin Brain Tumor Center, Department of Neurosurgery, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202, USA
| | | | | | | |
Collapse
|