1
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Young S, Schiffer C, Wagner A, Patz J, Potapenko A, Herrmann L, Nordhoff V, Pock T, Krallmann C, Stallmeyer B, Röpke A, Kierzek M, Biagioni C, Wang T, Haalck L, Deuster D, Hansen JN, Wachten D, Risse B, Behre HM, Schlatt S, Kliesch S, Tüttelmann F, Brenker C, Strünker T. Human fertilization in vivo and in vitro requires the CatSper channel to initiate sperm hyperactivation. J Clin Invest 2024; 134:e173564. [PMID: 38165034 PMCID: PMC10760960 DOI: 10.1172/jci173564] [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: 06/29/2023] [Accepted: 10/31/2023] [Indexed: 01/03/2024] Open
Abstract
The infertility of many couples rests on an enigmatic dysfunction of the man's sperm. To gain insight into the underlying pathomechanisms, we assessed the function of the sperm-specific multisubunit CatSper-channel complex in the sperm of almost 2,300 men undergoing a fertility workup, using a simple motility-based test. We identified a group of men with normal semen parameters but defective CatSper function. These men or couples failed to conceive naturally and upon medically assisted reproduction via intrauterine insemination and in vitro fertilization. Intracytoplasmic sperm injection (ICSI) was, ultimately, required to conceive a child. We revealed that the defective CatSper function was caused by variations in CATSPER genes. Moreover, we unveiled that CatSper-deficient human sperm were unable to undergo hyperactive motility and, therefore, failed to penetrate the egg coat. Thus, our study provides the experimental evidence that sperm hyperactivation is required for human fertilization, explaining the infertility of CatSper-deficient men and the need of ICSI for medically assisted reproduction. Finally, our study also revealed that defective CatSper function and ensuing failure to hyperactivate represents the most common cause of unexplained male infertility known thus far and that this sperm channelopathy can readily be diagnosed, enabling future evidence-based treatment of affected couples.
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Affiliation(s)
- Samuel Young
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Christian Schiffer
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Alice Wagner
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
- Institute of Reproductive Genetics
| | - Jannika Patz
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Anton Potapenko
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Leonie Herrmann
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Verena Nordhoff
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Tim Pock
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Claudia Krallmann
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | | | | | - Michelina Kierzek
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
- CiM-IMPRS Graduate School
| | - Cristina Biagioni
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Tao Wang
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Lars Haalck
- Institute of Geoinformatics, Computer Vision and Machine Learning Systems, University of Münster, Münster, Germany
| | - Dirk Deuster
- Department of Phoniatrics and Pedaudiology, University Hospital Münster, University of Münster, Münster, Germany
| | - Jan N. Hansen
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Benjamin Risse
- Institute of Geoinformatics, Computer Vision and Machine Learning Systems, University of Münster, Münster, Germany
- Computer Science Department, University of Münster, Münster, Germany
| | - Hermann M. Behre
- UKM Fertility Centre, University Hospital Münster, Münster, Germany
| | - Stefan Schlatt
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Sabine Kliesch
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | | | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Timo Strünker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
- Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
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2
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Abstract
Cell morphology and motility drive the cellular capabilities to interact with the environment. For example, microglia, the longest known tissue-resident macrophages, show a highly branched process tree with which they continuously scan their environment. Computational image analysis allows to quantify morphology and/or motility from images of tissue-resident macrophages. Here, I describe a step-by-step protocol for analyzing the morphology (and motility) of macrophages with our recently described, freely available software MotiQ, which provides a broad band of parameters and thereby serves as a versatile tool for studies of morphology and motility.
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Affiliation(s)
- Jan N Hansen
- Science for Life Laboratory, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH - Royal Institute of Technology, Stockholm, Sweden.
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3
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Schneider S, Kovacevic A, Mayer M, Dicke AK, Arévalo L, Koser SA, Hansen JN, Young S, Brenker C, Kliesch S, Wachten D, Kirfel G, Struenker T, Tüttelmann F, Schorle H. Cylicins are a structural component of the sperm calyx being indispensable for male fertility in mice and human. eLife 2023; 12:RP86100. [PMID: 38013430 PMCID: PMC10684152 DOI: 10.7554/elife.86100] [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] [Indexed: 11/29/2023] Open
Abstract
Cylicins are testis-specific proteins, which are exclusively expressed during spermiogenesis. In mice and humans, two Cylicins, the gonosomal X-linked Cylicin 1 (Cylc1/CYLC1) and the autosomal Cylicin 2 (Cylc2/CYLC2) genes, have been identified. Cylicins are cytoskeletal proteins with an overall positive charge due to lysine-rich repeats. While Cylicins have been localized in the acrosomal region of round spermatids, they resemble a major component of the calyx within the perinuclear theca at the posterior part of mature sperm nuclei. However, the role of Cylicins during spermiogenesis has not yet been investigated. Here, we applied CRISPR/Cas9-mediated gene editing in zygotes to establish Cylc1- and Cylc2-deficient mouse lines as a model to study the function of these proteins. Cylc1 deficiency resulted in male subfertility, whereas Cylc2-/-, Cylc1-/yCylc2+/-, and Cylc1-/yCylc2-/- males were infertile. Phenotypical characterization revealed that loss of Cylicins prevents proper calyx assembly during spermiogenesis. This results in decreased epididymal sperm counts, impaired shedding of excess cytoplasm, and severe structural malformations, ultimately resulting in impaired sperm motility. Furthermore, exome sequencing identified an infertile man with a hemizygous variant in CYLC1 and a heterozygous variant in CYLC2, displaying morphological abnormalities of the sperm including the absence of the acrosome. Thus, our study highlights the relevance and importance of Cylicins for spermiogenic remodeling and male fertility in human and mouse, and provides the basis for further studies on unraveling the complex molecular interactions between perinuclear theca proteins required during spermiogenesis.
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Affiliation(s)
- Simon Schneider
- Institute of Pathology, Department of Developmental Pathology, Medical Faculty, University of BonnBonnGermany
- Bonn Technology Campus, Core Facility 'Gene-Editing', Medical Faculty, University of BonnBonnGermany
| | - Andjela Kovacevic
- Institute of Pathology, Department of Developmental Pathology, Medical Faculty, University of BonnBonnGermany
| | - Michelle Mayer
- Institute of Pathology, Department of Developmental Pathology, Medical Faculty, University of BonnBonnGermany
| | - Ann-Kristin Dicke
- Institute of Reproductive Genetics, University of MünsterMünsterGermany
| | - Lena Arévalo
- Institute of Pathology, Department of Developmental Pathology, Medical Faculty, University of BonnBonnGermany
| | - Sophie A Koser
- Institute of Reproductive Genetics, University of MünsterMünsterGermany
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Samuel Young
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of MünsterMünsterGermany
| | - Christoph Brenker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of MünsterMünsterGermany
| | - Sabine Kliesch
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of MünsterMünsterGermany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Gregor Kirfel
- Institute for Cell Biology, University of BonnBonnGermany
| | - Timo Struenker
- Centre of Reproductive Medicine and Andrology, University Hospital Münster, University of MünsterMünsterGermany
| | - Frank Tüttelmann
- Institute of Reproductive Genetics, University of MünsterMünsterGermany
| | - Hubert Schorle
- Institute of Pathology, Department of Developmental Pathology, Medical Faculty, University of BonnBonnGermany
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4
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Hansen JN, Brückner M, Pietrowski MJ, Jikeli JF, Plescher M, Beckert H, Schnaars M, Fülle L, Reitmeier K, Langmann T, Förster I, Boche D, Petzold GC, Halle A. MotiQ: an open-source toolbox to quantify the cell motility and morphology of microglia. Mol Biol Cell 2022; 33:ar99. [PMID: 35731557 DOI: 10.1091/mbc.e21-11-0585] [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: 11/11/2022] Open
Abstract
Microglia are the primary resident innate immune cells of the CNS. They possess branched, motile cell processes that are important for their cellular functions. To study the pathways that control microglial morphology and motility under physiological and disease conditions, it is necessary to quantify microglial morphology and motility precisely and reliably. Several image analysis approaches are available for the quantification of microglial morphology and motility. However, they are either not automated, not freely accessible, and/or limited in the number of morphology and motility parameters that can be assessed. Thus, we have developed MotiQ, an open-source, freely accessible software for automated quantification of microglial motility and morphology. MotiQ allows quantification of a diverse set of cellular motility and morphology parameters, including the parameters that have become the gold standard in the microglia field. We demonstrate that MotiQ can be applied to in vivo, ex vivo, and in vitro data from confocal, epifluorescence, or two-photon microscopy, and we compare its results to other analysis approaches. We suggest MotiQ as a versatile and customizable tool to study microglia.
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Affiliation(s)
- Jan N Hansen
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany.,Max-Planck Research Group Neuroimmunology and
| | | | - Marie J Pietrowski
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Jan F Jikeli
- Minerva Research Group Molecular Physiology, Research Center Caesar, 53175 Bonn, Germany
| | - Monika Plescher
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany.,Max-Planck Research Group Neuroimmunology and
| | - Hannes Beckert
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany.,Max-Planck Research Group Neuroimmunology and
| | | | - Lorenz Fülle
- Immunology and Environment, Life and Medical Sciences (LIMES) Institute, University of Bonn, 53115 Bonn, Germany
| | - Katharina Reitmeier
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Irmgard Förster
- Immunology and Environment, Life and Medical Sciences (LIMES) Institute, University of Bonn, 53115 Bonn, Germany
| | - Delphine Boche
- Clinical Neurosciences and Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany.,Department of Neurology and
| | - Annett Halle
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany.,Max-Planck Research Group Neuroimmunology and.,Department of Neuropathology, University Hospital Bonn, 53127 Bonn, Germany
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5
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Sieckmann K, Winnerling N, Huebecker M, Leyendecker P, Ribeiro D, Gnad T, Pfeifer A, Wachten D, Hansen JN. AdipoQ - a simple, open-source software to quantify adipocyte morphology and function in tissues and in vitro. Mol Biol Cell 2022; 33:br22. [PMID: 35947507 DOI: 10.1091/mbc.e21-11-0592] [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: 11/11/2022] Open
Abstract
The different adipose tissues can be distinguished according to their function. For example, white adipose tissue (WAT) stores energy in form of lipids, whereas brown adipose tissue (BAT) dissipates energy in the form of heat. These functional differences are represented in the respective adipocyte morphology: whereas white adipocytes contain large, unilocular lipid droplets, brown adipocytes contain smaller, multilocular lipid droplets. However, an automated, image-analysis pipeline to comprehensively analyze adipocytes in vitro in cell culture as well as ex vivo in tissue sections is missing. We here present AdipoQ, an open-source software implemented as ImageJ plugins that allows to analyze adipocytes in tissue sections and in vitro after histological and/or immunofluorescent labelling. AdipoQ is compatible with different imaging modalities and staining methods, allows batch processing of large datasets and simple post-hoc analysis, provides a broad band of parameters, and allows combining multiple fluorescent read-outs. Thereby, AdipoQ is of immediate use not only for basic research but also for clinical diagnosis.
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Affiliation(s)
- Katharina Sieckmann
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Nora Winnerling
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Mylene Huebecker
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Philipp Leyendecker
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Dalila Ribeiro
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Thorsten Gnad
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, 53127 Bonn, Germany
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6
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Hansen JN, Kaiser F, Leyendecker P, Stüven B, Krause JH, Derakhshandeh F, Irfan J, Sroka TJ, Preval KM, Desai PB, Kraut M, Theis H, Drews AD, De-Domenico E, Händler K, Pazour GJ, Henderson DJP, Mick DU, Wachten D. A cAMP signalosome in primary cilia drives gene expression and kidney cyst formation. EMBO Rep 2022; 23:e54315. [PMID: 35695071 PMCID: PMC9346484 DOI: 10.15252/embr.202154315] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 05/11/2022] [Accepted: 05/19/2022] [Indexed: 12/22/2022] Open
Abstract
The primary cilium constitutes an organelle that orchestrates signal transduction independently from the cell body. Dysregulation of this intricate molecular architecture leads to severe human diseases, commonly referred to as ciliopathies. However, the molecular underpinnings how ciliary signaling orchestrates a specific cellular output remain elusive. By combining spatially resolved optogenetics with RNA sequencing and imaging, we reveal a novel cAMP signalosome that is functionally distinct from the cytoplasm. We identify the genes and pathways targeted by the ciliary cAMP signalosome and shed light on the underlying mechanisms and downstream signaling. We reveal that chronic stimulation of the ciliary cAMP signalosome transforms kidney epithelia from tubules into cysts. Counteracting this chronic cAMP elevation in the cilium by small molecules targeting activation of phosphodiesterase‐4 long isoforms inhibits cyst growth. Thereby, we identify a novel concept of how the primary cilium controls cellular functions and maintains tissue integrity in a specific and spatially distinct manner and reveal novel molecular components that might be involved in the development of one of the most common genetic diseases, polycystic kidney disease.
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Affiliation(s)
- Jan N Hansen
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Fabian Kaiser
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Philipp Leyendecker
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Birthe Stüven
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Jens-Henning Krause
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | | | | | - Tommy J Sroka
- Center for Molecular Signaling (PZMS), Center of Human and Molecular Biology (ZHMB), Saarland University, School of Medicine, Homburg, Germany
| | - Kenley M Preval
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, MA, USA
| | - Paurav B Desai
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, MA, USA
| | - Michael Kraut
- Precise Platform for Single Cell Genomics and Epigenomics, Department of Systems Medicine, German Center for Neurogenerative Diseases, Bonn, Germany
| | - Heidi Theis
- Precise Platform for Single Cell Genomics and Epigenomics, Department of Systems Medicine, German Center for Neurogenerative Diseases, Bonn, Germany
| | - Anna-Dorothee Drews
- Precise Platform for Single Cell Genomics and Epigenomics, Department of Systems Medicine, German Center for Neurogenerative Diseases, Bonn, Germany
| | - Elena De-Domenico
- Precise Platform for Single Cell Genomics and Epigenomics, Department of Systems Medicine, German Center for Neurogenerative Diseases, Bonn, Germany
| | - Kristian Händler
- Precise Platform for Single Cell Genomics and Epigenomics, Department of Systems Medicine, German Center for Neurogenerative Diseases, Bonn, Germany
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, MA, USA
| | | | - David U Mick
- Center for Molecular Signaling (PZMS), Center of Human and Molecular Biology (ZHMB), Saarland University, School of Medicine, Homburg, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
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7
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Reusch N, Ravichandran KA, Olabiyi BF, Komorowska-Müller JA, Hansen JN, Ulas T, Beyer M, Zimmer A, Schmöle AC. Cannabinoid receptor 2 is necessary to induce toll-like receptor-mediated microglial activation. Glia 2021; 70:71-88. [PMID: 34499767 DOI: 10.1002/glia.24089] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [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: 06/29/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 01/17/2023]
Abstract
The tight regulation of microglia activity is key for precise responses to potential threats, while uncontrolled and exacerbated microglial activity is neurotoxic. Microglial toll-like receptors (TLRs) are indispensable for sensing different types of assaults and triggering an innate immune response. Cannabinoid receptor 2 (CB2) signaling is a key pathway to control microglial homeostasis and activation, and its activation is connected to changes in microglial activity. We aimed to investigate how CB2 signaling impacts TLR-mediated microglial activation. Here, we demonstrate that deletion of CB2 causes a dampened transcriptional response to prototypic TLR ligands in microglia. Loss of CB2 results in distinct microglial gene expression profiles, morphology, and activation. We show that the CB2-mediated attenuation of TLR-induced microglial activation is mainly p38 MAPK-dependent. Taken together, we demonstrate that CB2 expression and signaling are necessary to fine-tune TLR-induced activation programs in microglia.
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Affiliation(s)
- Nico Reusch
- Systems Medicine, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Genomics and Immunoregulation, Life and Medical Sciences Institute (LIMES), Bonn, Germany
| | | | | | - Joanna Agnieszka Komorowska-Müller
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany.,International Max Planck Research School for Brain and Behavior, University of Bonn, Bonn, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Thomas Ulas
- Systems Medicine, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Genomics and Immunoregulation, Life and Medical Sciences Institute (LIMES), Bonn, Germany.,Platform for Single Cell Genomics and Epigenomics (PRECISE), German Center for Neurodegenerative Diseases (DZNE), University of Bonn, Bonn, Germany
| | - Marc Beyer
- Platform for Single Cell Genomics and Epigenomics (PRECISE), German Center for Neurodegenerative Diseases (DZNE), University of Bonn, Bonn, Germany.,Molecular Immunology in Neurodegeneration, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Andreas Zimmer
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne-Caroline Schmöle
- Institute for Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
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8
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Haward F, Maslon MM, Yeyati PL, Bellora N, Hansen JN, Aitken S, Lawson J, von Kriegsheim A, Wachten D, Mill P, Adams IR, Caceres JF. Nucleo-cytoplasmic shuttling of splicing factor SRSF1 is required for development and cilia function. eLife 2021; 10:e65104. [PMID: 34338635 PMCID: PMC8352595 DOI: 10.7554/elife.65104] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 11/23/2020] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
Shuttling RNA-binding proteins coordinate nuclear and cytoplasmic steps of gene expression. The SR family proteins regulate RNA splicing in the nucleus and a subset of them, including SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring an SRSF1 protein that is retained exclusively in the nucleus. Srsf1NRS/NRS mutants displayed small body size, hydrocephalus, and immotile sperm, all traits associated with ciliary defects. We observed reduced translation of a subset of mRNAs and decreased abundance of proteins involved in multiciliogenesis, with disruption of ciliary ultrastructure and motility in cells and tissues derived from this mouse model. These results demonstrate that SRSF1 shuttling is used to reprogram gene expression networks in the context of high cellular demands, as observed here, during motile ciliogenesis.
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Affiliation(s)
- Fiona Haward
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Magdalena M Maslon
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Patricia L Yeyati
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Nicolas Bellora
- Institute of Nuclear Technologies for Health (Intecnus), National Scientific and Technical Research Council (CONICET)BarilocheArgentina
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Stuart Aitken
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Jennifer Lawson
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Alex von Kriegsheim
- Edinburgh Cancer Research United Kingdom Centre, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Ian R Adams
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Javier F Caceres
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
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9
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Hansen JN, Gong A, Wachten D, Pascal R, Turpin A, Jikeli JF, Kaupp UB, Alvarez L. Multifocal imaging for precise, label-free tracking of fast biological processes in 3D. Nat Commun 2021; 12:4574. [PMID: 34321468 PMCID: PMC8319204 DOI: 10.1038/s41467-021-24768-4] [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: 05/17/2020] [Accepted: 07/06/2021] [Indexed: 11/22/2022] Open
Abstract
Many biological processes happen on a nano- to millimeter scale and within milliseconds. Established methods such as confocal microscopy are suitable for precise 3D recordings but lack the temporal or spatial resolution to resolve fast 3D processes and require labeled samples. Multifocal imaging (MFI) allows high-speed 3D imaging but is limited by the compromise between high spatial resolution and large field-of-view (FOV), and the requirement for bright fluorescent labels. Here, we provide an open-source 3D reconstruction algorithm for multi-focal images that allows using MFI for fast, precise, label-free tracking spherical and filamentous structures in a large FOV and across a high depth. We characterize fluid flow and flagellar beating of human and sea urchin sperm with a z-precision of 0.15 µm, in a volume of 240 × 260 × 21 µm, and at high speed (500 Hz). The sampling volume allowed to follow sperm trajectories while simultaneously recording their flagellar beat. Our MFI concept is cost-effective, can be easily implemented, and does not rely on object labeling, which renders it broadly applicable.
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Affiliation(s)
- Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany.
| | - An Gong
- Center of Advanced European Studies and Research (caesar), Molecular Sensory Systems, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - René Pascal
- Center of Advanced European Studies and Research (caesar), Molecular Sensory Systems, Bonn, Germany
| | - Alex Turpin
- School of Computing Science, University of Glasgow, Glasgow, UK
| | - Jan F Jikeli
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research (caesar), Molecular Sensory Systems, Bonn, Germany
- Life & Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Luis Alvarez
- Center of Advanced European Studies and Research (caesar), Molecular Sensory Systems, Bonn, Germany.
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10
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Balbach M, Hamzeh H, Jikeli JF, Brenker C, Schiffer C, Hansen JN, Neugebauer P, Trötschel C, Jovine L, Han L, Florman HM, Kaupp UB, Strünker T, Wachten D. Molecular Mechanism Underlying the Action of Zona-pellucida Glycoproteins on Mouse Sperm. Front Cell Dev Biol 2020; 8:572735. [PMID: 32984353 PMCID: PMC7487327 DOI: 10.3389/fcell.2020.572735] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [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: 06/15/2020] [Accepted: 08/12/2020] [Indexed: 01/10/2023] Open
Abstract
Mammalian oocytes are enveloped by the zona pellucida (ZP), an extracellular matrix of glycoproteins. In sperm, stimulation with ZP proteins evokes a rapid Ca2+ influx via the sperm-specific, pH-sensitive Ca2+ channel CatSper. However, the physiological role and molecular mechanisms underlying ZP-dependent activation of CatSper are unknown. Here, we delineate the sequence of ZP-signaling events in mouse sperm. We show that ZP proteins evoke a rapid intracellular pHi increase that rests predominantly on Na+/H+ exchange by NHA1 and requires cAMP synthesis by the soluble adenylyl cyclase sAC as well as a sufficiently negative membrane potential set by the spem-specific K+ channel Slo3. The alkaline-activated CatSper channel translates the ZP-induced pHi increase into a Ca2+ response. Our findings reveal the molecular components underlying ZP action on mouse sperm, opening up new avenues for understanding the basic principles of sperm function and, thereby, mammalian fertilization.
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Affiliation(s)
- Melanie Balbach
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany
| | - Hussein Hamzeh
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany
| | - Jan F Jikeli
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christoph Brenker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Christian Schiffer
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Pia Neugebauer
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | | | - Luca Jovine
- Department of Biosciences and Nutrition, Karolinska Institutet, Solna, Sweden
| | - Ling Han
- Department of Biosciences and Nutrition, Karolinska Institutet, Solna, Sweden
| | - Harvey M Florman
- Department of Obstetrics and Gynecology, University of Massachusetts Medical School Worcester, Worcester, MA, United States
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research, Department of Molecular Sensory Systems, Bonn, Germany.,Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Timo Strünker
- Center of Reproductive Medicine and Andrology, University Hospital Münster, University of Münster, Münster, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
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11
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Oura S, Kazi S, Savolainen A, Nozawa K, Castañeda J, Yu Z, Miyata H, Matzuk RM, Hansen JN, Wachten D, Matzuk MM, Prunskaite-Hyyryläinen R. Cfap97d1 is important for flagellar axoneme maintenance and male mouse fertility. PLoS Genet 2020; 16:e1008954. [PMID: 32785227 PMCID: PMC7444823 DOI: 10.1371/journal.pgen.1008954] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 08/24/2020] [Accepted: 06/24/2020] [Indexed: 11/18/2022] Open
Abstract
The flagellum is essential for sperm motility and fertilization in vivo. The axoneme is the main component of the flagella, extending through its entire length. An axoneme is comprised of two central microtubules surrounded by nine doublets, the nexin-dynein regulatory complex, radial spokes, and dynein arms. Failure to properly assemble components of the axoneme in a sperm flagellum, leads to fertility alterations. To understand this process in detail, we have defined the function of an uncharacterized gene, Cfap97 domain containing 1 (Cfap97d1). This gene is evolutionarily conserved in mammals and multiple other species, including Chlamydomonas. We have used two independently generated Cfap97d1 knockout mouse models to study the gene function in vivo. Cfap97d1 is exclusively expressed in testes starting from post-natal day 20 and continuing throughout adulthood. Deletion of the Cfap97d1 gene in both mouse models leads to sperm motility defects (asthenozoospermia) and male subfertility. In vitro fertilization (IVF) of cumulus-intact oocytes with Cfap97d1 deficient sperm yielded few embryos whereas IVF with zona pellucida-free oocytes resulted in embryo numbers comparable to that of the control. Knockout spermatozoa showed abnormal motility characterized by frequent stalling in the anti-hook position. Uniquely, Cfap97d1 loss caused a phenotype associated with axonemal doublet heterogeneity linked with frequent loss of the fourth doublet in the sperm stored in the epididymis. This study demonstrates that Cfap97d1 is required for sperm flagellum ultra-structure maintenance, thereby playing a critical role in sperm function and male fertility in mice.
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Affiliation(s)
- Seiya Oura
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Samina Kazi
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Audrey Savolainen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Kaori Nozawa
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Drug Discovery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Julio Castañeda
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Zhifeng Yu
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Drug Discovery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Haruhiko Miyata
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Ryan M. Matzuk
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Drug Discovery, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jan N. Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of Bonn, Bonn, Germany
| | - Martin M. Matzuk
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Drug Discovery, Baylor College of Medicine, Houston, Texas, United States of America
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12
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Hansen JN, Kaiser F, Klausen C, Stüven B, Chong R, Bönigk W, Mick DU, Möglich A, Jurisch-Yaksi N, Schmidt FI, Wachten D. Nanobody-directed targeting of optogenetic tools to study signaling in the primary cilium. eLife 2020; 9:e57907. [PMID: 32579112 PMCID: PMC7338050 DOI: 10.7554/elife.57907] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022] Open
Abstract
Compartmentalization of cellular signaling forms the molecular basis of cellular behavior. The primary cilium constitutes a subcellular compartment that orchestrates signal transduction independent from the cell body. Ciliary dysfunction causes severe diseases, termed ciliopathies. Analyzing ciliary signaling has been challenging due to the lack of tools to investigate ciliary signaling. Here, we describe a nanobody-based targeting approach for optogenetic tools in mammalian cells and in vivo in zebrafish to specifically analyze ciliary signaling and function. Thereby, we overcome the loss of protein function observed after fusion to ciliary targeting sequences. We functionally localized modifiers of cAMP signaling, the photo-activated adenylyl cyclase bPAC and the light-activated phosphodiesterase LAPD, and the cAMP biosensor mlCNBD-FRET to the cilium. Using this approach, we studied the contribution of spatial cAMP signaling in controlling cilia length. Combining optogenetics with nanobody-based targeting will pave the way to the molecular understanding of ciliary function in health and disease.
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Affiliation(s)
- Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Fabian Kaiser
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Christina Klausen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Birthe Stüven
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Raymond Chong
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Wolfgang Bönigk
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar)BonnGermany
| | - David U Mick
- Center for Molecular Signaling (PZMS), Center of Human and Molecular Biology (ZHMB), Saarland University, School of MedicineHomburgGermany
| | - Andreas Möglich
- Lehrstuhl für Biochemie, Universität BayreuthBayreuthGermany
- Research Center for Bio-Macromolecules, Universität BayreuthBayreuthGermany
- Bayreuth Center for Biochemistry & Molecular Biology, Universität BayreuthBayreuthGermany
| | - Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and TechnologyTrondheimNorway
- Department of Neurology and Clinical Neurophysiology, St. Olavs University HospitalTrondheimNorway
| | - Florian I Schmidt
- Institute of Innate Immunity, Emmy Noether research group, Medical Faculty, University of BonnBonnGermany
- Core Facility Nanobodies, University of BonnBonnGermany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
- Research Group Molecular Physiology, Center of Advanced European Studies and Research (caesar)BonnGermany
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13
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Carvalho K, Faivre E, Pietrowski MJ, Marques X, Gomez-Murcia V, Deleau A, Huin V, Hansen JN, Kozlov S, Danis C, Temido-Ferreira M, Coelho JE, Mériaux C, Eddarkaoui S, Gras SL, Dumoulin M, Cellai L, Landrieu I, Chern Y, Hamdane M, Buée L, Boutillier AL, Levi S, Halle A, Lopes LV, Blum D. Exacerbation of C1q dysregulation, synaptic loss and memory deficits in tau pathology linked to neuronal adenosine A2A receptor. Brain 2020; 142:3636-3654. [PMID: 31599329 PMCID: PMC6821333 DOI: 10.1093/brain/awz288] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [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: 03/19/2019] [Revised: 07/24/2019] [Accepted: 07/26/2019] [Indexed: 12/14/2022] Open
Abstract
Accumulating data support the role of tau pathology in cognitive decline in ageing and Alzheimer’s disease, but underlying mechanisms remain ill-defined. Interestingly, ageing and Alzheimer’s disease have been associated with an abnormal upregulation of adenosine A2A receptor (A2AR), a fine tuner of synaptic plasticity. However, the link between A2AR signalling and tau pathology has remained largely unexplored. In the present study, we report for the first time a significant upregulation of A2AR in patients suffering from frontotemporal lobar degeneration with the MAPT P301L mutation. To model these alterations, we induced neuronal A2AR upregulation in a tauopathy mouse model (THY-Tau22) using a new conditional strain allowing forebrain overexpression of the receptor. We found that neuronal A2AR upregulation increases tau hyperphosphorylation, potentiating the onset of tau-induced memory deficits. This detrimental effect was linked to a singular microglial signature as revealed by RNA sequencing analysis. In particular, we found that A2AR overexpression in THY-Tau22 mice led to the hippocampal upregulation of C1q complement protein—also observed in patients with frontotemporal lobar degeneration—and correlated with the loss of glutamatergic synapses, likely underlying the observed memory deficits. These data reveal a key impact of overactive neuronal A2AR in the onset of synaptic loss in tauopathies, paving the way for new therapeutic approaches.
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Affiliation(s)
- Kevin Carvalho
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Emilie Faivre
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | | | - Xavier Marques
- Institut du Fer à Moulin, Inserm UMR-S 1270, Sorbonne Université, F, Paris, France
| | - Victoria Gomez-Murcia
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Aude Deleau
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Vincent Huin
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Jan N Hansen
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stanislav Kozlov
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Clément Danis
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France.,University of Lille, CNRS UMR8576, Unité de Glycobiologie Structurale et Fonctionnelle, LabEx DISTALZ, Lille, F Lille, France
| | - Mariana Temido-Ferreira
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Joana E Coelho
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Céline Mériaux
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Sabiha Eddarkaoui
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Stéphanie Le Gras
- CNRS, Inserm, UMR 7104, GenomEast Platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, F Illkirch, France
| | | | - Lucrezia Cellai
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | | | - Isabelle Landrieu
- University of Lille, CNRS UMR8576, Unité de Glycobiologie Structurale et Fonctionnelle, LabEx DISTALZ, Lille, F Lille, France
| | - Yijuang Chern
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Malika Hamdane
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Luc Buée
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
| | - Anne-Laurence Boutillier
- Laboratoire de Neuroscience Cognitives et Adaptatives (LNCA), CNRS UMR 7364, Université de Strasbourg, F Strasbourg, France
| | - Sabine Levi
- Institut du Fer à Moulin, Inserm UMR-S 1270, Sorbonne Université, F, Paris, France
| | - Annett Halle
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Luisa V Lopes
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - David Blum
- University of Lille, Inserm, CHU Lille, UMR-S 1172 - JPArc, LabEx DISTALZ, F Lille, France
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14
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Klaus C, Hansen JN, Ginolhac A, Gérard D, Gnanapragassam VS, Horstkorte R, Rossdam C, Buettner FFR, Sauter T, Sinkkonen L, Neumann H, Linnartz-Gerlach B. Reduced sialylation triggers homeostatic synapse and neuronal loss in middle-aged mice. Neurobiol Aging 2020; 88:91-107. [PMID: 32087947 DOI: 10.1016/j.neurobiolaging.2020.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [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: 09/09/2019] [Revised: 01/06/2020] [Accepted: 01/14/2020] [Indexed: 12/21/2022]
Abstract
Sialic acid-binding Ig-like lectin (Siglec) receptors are linked to neurodegenerative processes, but the role of sialic acids in physiological aging is still not fully understood. We investigated the impact of reduced sialylation in the brain of mice heterozygous for the enzyme glucosamine-2-epimerase/N-acetylmannosamine kinase (GNE+/-) that is essential for sialic acid biosynthesis. We demonstrate that GNE+/- mice have hyposialylation in different brain regions, less synapses in the hippocampus and reduced microglial arborization already at 6 months followed by increased loss of neurons at 12 months. A transcriptomic analysis revealed no pro-inflammatory changes indicating an innate homeostatic immune process leading to the removal of synapses and neurons in GNE+/- mice during aging. Crossbreeding with complement C3-deficient mice rescued the earlier onset of neuronal and synaptic loss as well as the changes in microglial arborization. Thus, sialic acids of the glycocalyx contribute to brain homeostasis and act as a recognition system for the innate immune system in the brain.
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Affiliation(s)
- Christine Klaus
- Neural Regeneration, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
| | - Jan N Hansen
- Biophysical Imaging, Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Aurélien Ginolhac
- Epigenetics Team, Systems Biology Group, Life Sciences Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - Deborah Gérard
- Epigenetics Team, Systems Biology Group, Life Sciences Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - Vinayaga S Gnanapragassam
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Rüdiger Horstkorte
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Charlotte Rossdam
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Falk F R Buettner
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Thomas Sauter
- Epigenetics Team, Systems Biology Group, Life Sciences Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - Lasse Sinkkonen
- Epigenetics Team, Systems Biology Group, Life Sciences Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - Harald Neumann
- Neural Regeneration, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany.
| | - Bettina Linnartz-Gerlach
- Neural Regeneration, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Bonn, Germany
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15
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Schmöle AC, Lundt R, Toporowski G, Hansen JN, Beins E, Halle A, Zimmer A. Cannabinoid Receptor 2-Deficiency Ameliorates Disease Symptoms in a Mouse Model with Alzheimer's Disease-Like Pathology. J Alzheimers Dis 2019; 64:379-392. [PMID: 29865078 DOI: 10.3233/jad-180230] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
It is widely accepted that the endocannabinoid system (ECS) is a modulator of neuroinflammation associated with neurodegenerative disorders, including Alzheimer's disease (AD). Thus, expression of the cannabinoid receptor 2 (CB2) is induced in plaque-associated microglia and astrocytes in brain tissues from AD patients and in genetic mouse models expressing pathogenic variants of the amyloid precursor protein (APP). However, the exact mechanism of CB2 signaling in this mouse model remains elusive, because the genetic deletion of CB2 and the pharmacological activation of CB2 both reduced neuroinflammation. Here, we demonstrate that CB2 deletion also improved cognitive and learning deficits in APP/PS1*CB2-/- mice. This was accompanied by reduced neuronal loss and decreased plaque levels and coincided with increased expression of Aβ degrading enzymes. Interestingly, plaque-associated microglia in APP/PS1*CB2-/- mice showed a less activated morphology, while plaques were smaller and more condensed than in APP/PS1 mice. Taken together, these results indicate a beneficial effect of CB2-deficiency in APP transgenic mice. CB2 appears to be part of a protective system that may be detrimental when engaged continuously.
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Affiliation(s)
- Anne-Caroline Schmöle
- Institute of Molecular Psychiatry, University of Bonn, Medical Faculty, Bonn, Germany
| | - Ramona Lundt
- Institute of Molecular Psychiatry, University of Bonn, Medical Faculty, Bonn, Germany
| | - Gregor Toporowski
- Institute of Molecular Psychiatry, University of Bonn, Medical Faculty, Bonn, Germany
| | - Jan N Hansen
- Center of Advanced European Studies and Research (Caesar), Max Planck research group "Neuroimmunology", Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Eva Beins
- Institute of Molecular Psychiatry, University of Bonn, Medical Faculty, Bonn, Germany
| | - Annett Halle
- Center of Advanced European Studies and Research (Caesar), Max Planck research group "Neuroimmunology", Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, University of Bonn, Medical Faculty, Bonn, Germany
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16
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Raju DN, Hansen JN, Rassmann S, Stüven B, Jikeli JF, Strünker T, Körschen HG, Möglich A, Wachten D. Cyclic Nucleotide-Specific Optogenetics Highlights Compartmentalization of the Sperm Flagellum into cAMP Microdomains. Cells 2019; 8:cells8070648. [PMID: 31252584 PMCID: PMC6679001 DOI: 10.3390/cells8070648] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/13/2019] [Accepted: 06/25/2019] [Indexed: 11/16/2022] Open
Abstract
Inside the female genital tract, mammalian sperm undergo a maturation process called capacitation, which primes the sperm to navigate across the oviduct and fertilize the egg. Sperm capacitation and motility are controlled by 3′,5′-cyclic adenosine monophosphate (cAMP). Here, we show that optogenetics, the control of cellular signaling by genetically encoded light-activated proteins, allows to manipulate cAMP dynamics in sperm flagella and, thereby, sperm capacitation and motility by light. To this end, we used sperm that express the light-activated phosphodiesterase LAPD or the photo-activated adenylate cyclase bPAC. The control of cAMP by LAPD or bPAC combined with pharmacological interventions provides spatiotemporal precision and allows to probe the physiological function of cAMP compartmentalization in mammalian sperm.
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Affiliation(s)
- Diana N Raju
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
- Centrum für Reproduktionsmedizin und Andrologie (CeRA), Universitätsklinikum Münster, Universität Münster, 48129 Münster, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Sebastian Rassmann
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Birthe Stüven
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
- Lehrstuhl für Biochemie, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Jan F Jikeli
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Timo Strünker
- Centrum für Reproduktionsmedizin und Andrologie (CeRA), Universitätsklinikum Münster, Universität Münster, 48129 Münster, Germany
| | - Heinz G Körschen
- Center of Advanced European Studies and Research (caesar), Molecular Sensory Systems, 53175 Bonn, Germany
| | - Andreas Möglich
- Lehrstuhl für Biochemie, Universität Bayreuth, 95447 Bayreuth, Germany
- Research Center for Bio-Macromolecules, Universität Bayreuth, 95447 Bayreuth, Germany
- Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth, 95447 Bayreuth, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany.
- Center of Advanced European Studies and Research (caesar), Molecular Physiology, 53175 Bonn, Germany.
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17
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Karunakaran I, Alam S, Jayagopi S, Frohberger SJ, Hansen JN, Kuehlwein J, Hölbling BV, Schumak B, Hübner MP, Gräler MH, Halle A, van Echten-Deckert G. Neural sphingosine 1-phosphate accumulation activates microglia and links impaired autophagy and inflammation. Glia 2019; 67:1859-1872. [PMID: 31231866 DOI: 10.1002/glia.23663] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [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: 09/10/2018] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 02/06/2023]
Abstract
Microglia mediated responses to neuronal damage in the form of neuroinflammation is a common thread propagating neuropathology. In this study, we investigated the microglial alterations occurring as a result of sphingosine 1-phosphate (S1P) accumulation in neural cells. We evidenced increased microglial activation in the brains of neural S1P-lyase (SGPL1) ablated mice (SGPL1fl/fl/Nes ) as shown by an activated and deramified morphology and increased activation markers on microglia. In addition, an increase of pro-inflammatory cytokines in sorted and primary cultured microglia generated from SGPL1 deficient mice was noticed. Further, we assessed autophagy, one of the major mechanisms in the brain that keeps inflammation in check. Indeed, microglial inflammation was accompanied by defective microglial autophagy in SGPL1 ablated mice. Rescuing autophagy by treatment with rapamycin was sufficient to decrease interleukin 6 (IL-6) but not tumor necrosis factor (TNF) secretion in cultured microglia. Rapamycin mediated decrease of IL-6 secretion suggests a particular mechanistic target of rapamycin (mTOR)-IL-6 link and appeared to be microglia specific. Using pharmacological inhibitors of the major receptors of S1P expressed in the microglia, we identified S1P receptor 2 (S1PR2) as the mediator of both impaired autophagy and proinflammatory effects. In line with these results, the addition of exogenous S1P to BV2 microglial cells showed similar effects as those observed in the genetic knock out of SGPL1 in the neural cells. In summary, we show a novel role of the S1P-S1PR2 axis in the microglia of mice with neural-targeted SGPL1 ablation and in BV2 microglial cell line exogenously treated with S1P.
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Affiliation(s)
- Indulekha Karunakaran
- LIMES Institute, Membrane Biology & Lipid Biochemistry, University of Bonn, Germany.,Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Shah Alam
- LIMES Institute, Membrane Biology & Lipid Biochemistry, University of Bonn, Germany
| | - Surendar Jayagopi
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Stefan J Frohberger
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Jan N Hansen
- German Center for Neurodegenerative Diseases, DZNE, Bonn, Germany and Center of Advanced European Studies and Research, Bonn, Germany
| | - Janina Kuehlwein
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Benedikt V Hölbling
- German Center for Neurodegenerative Diseases, DZNE, Bonn, Germany and Center of Advanced European Studies and Research, Bonn, Germany
| | - Beatrix Schumak
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Markus H Gräler
- Department of Anaesthesiology and Intensive Care Medicine, Center for Sepsis Control and Care (CSCC), and the Center for Molecular Biomedicine (CMB), Jena University Hospital, Jena, Germany
| | - Annett Halle
- German Center for Neurodegenerative Diseases, DZNE, Bonn, Germany and Center of Advanced European Studies and Research, Bonn, Germany
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18
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Woeste MA, Stern S, Raju DN, Grahn E, Dittmann D, Gutbrod K, Dörmann P, Hansen JN, Schonauer S, Marx CE, Hamzeh H, Körschen HG, Aerts JMFG, Bönigk W, Endepols H, Sandhoff R, Geyer M, Berger TK, Bradke F, Wachten D. Species-specific differences in nonlysosomal glucosylceramidase GBA2 function underlie locomotor dysfunction arising from loss-of-function mutations. J Biol Chem 2019; 294:3853-3871. [PMID: 30662006 DOI: 10.1074/jbc.ra118.006311] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/16/2019] [Indexed: 11/06/2022] Open
Abstract
The nonlysosomal glucosylceramidase β2 (GBA2) catalyzes the hydrolysis of glucosylceramide to glucose and ceramide. Mutations in the human GBA2 gene have been associated with hereditary spastic paraplegia (HSP), autosomal-recessive cerebellar ataxia (ARCA), and the Marinesco-Sjögren-like syndrome. However, the underlying molecular mechanisms are ill-defined. Here, using biochemistry, immunohistochemistry, structural modeling, and mouse genetics, we demonstrate that all but one of the spastic gait locus #46 (SPG46)-connected mutations cause a loss of GBA2 activity. We demonstrate that GBA2 proteins form oligomeric complexes and that protein-protein interactions are perturbed by some of these mutations. To study the pathogenesis of GBA2-related HSP and ARCA in vivo, we investigated GBA2-KO mice as a mammalian model system. However, these mice exhibited a high phenotypic variance and did not fully resemble the human phenotype, suggesting that mouse and human GBA2 differ in function. Whereas some GBA2-KO mice displayed a strong locomotor defect, others displayed only mild alterations of the gait pattern and no signs of cerebellar defects. On a cellular level, inhibition of GBA2 activity in isolated cerebellar neurons dramatically affected F-actin dynamics and reduced neurite outgrowth, which has been associated with the development of neurological disorders. Our results shed light on the molecular mechanism underlying the pathogenesis of GBA2-related HSP and ARCA and reveal species-specific differences in GBA2 function in vivo.
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Affiliation(s)
- Marina A Woeste
- From the Institute of Innate Immunity, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - Sina Stern
- the German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Diana N Raju
- From the Institute of Innate Immunity, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - Elena Grahn
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Dominik Dittmann
- From the Institute of Innate Immunity, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - Katharina Gutbrod
- the Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Peter Dörmann
- the Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, 53115 Bonn, Germany
| | - Jan N Hansen
- From the Institute of Innate Immunity, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - Sophie Schonauer
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Carina E Marx
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Hussein Hamzeh
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Heinz G Körschen
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Johannes M F G Aerts
- the Leiden Institute of Chemistry, Leiden University, 2333 CD Leiden, The Netherlands
| | - Wolfgang Bönigk
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Heike Endepols
- the Institute of Radiochemistry and Experimental Molecular Imaging (IREMB) and Department of Nuclear Medicine, University Hospital of Cologne, 50937 Cologne, Germany
| | - Roger Sandhoff
- the Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany.,the Lipid Pathobiochemistry Group, German Cancer Research Center, 69120 Heidelberg, Germany, and
| | - Matthias Geyer
- the Institute of Structural Biology, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - Thomas K Berger
- the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
| | - Frank Bradke
- the German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Dagmar Wachten
- From the Institute of Innate Immunity, University Hospital, University of Bonn, 53127 Bonn, Germany, .,the Center of Advanced European Studies and Research (Caesar), 53175 Bonn, Germany
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19
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Olstad EW, Ringers C, Hansen JN, Wens A, Brandt C, Wachten D, Yaksi E, Jurisch-Yaksi N. Ciliary Beating Compartmentalizes Cerebrospinal Fluid Flow in the Brain and Regulates Ventricular Development. Curr Biol 2019; 29:229-241.e6. [PMID: 30612902 PMCID: PMC6345627 DOI: 10.1016/j.cub.2018.11.059] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [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: 06/15/2018] [Revised: 10/31/2018] [Accepted: 11/27/2018] [Indexed: 12/17/2022]
Abstract
Motile cilia are miniature, propeller-like extensions, emanating from many cell types across the body. Their coordinated beating generates a directional fluid flow, which is essential for various biological processes, from respiration to reproduction. In the nervous system, ependymal cells extend their motile cilia into the brain ventricles and contribute to cerebrospinal fluid (CSF) flow. Although motile cilia are not the only contributors to CSF flow, their functioning is crucial, as patients with motile cilia defects develop clinical features, like hydrocephalus and scoliosis. CSF flow was suggested to primarily deliver nutrients and remove waste, but recent studies emphasized its role in brain development and function. Nevertheless, it remains poorly understood how ciliary beating generates and organizes CSF flow to fulfill these roles. Here, we study motile cilia and CSF flow in the brain ventricles of larval zebrafish. We identified that different populations of motile ciliated cells are spatially organized and generate a directional CSF flow powered by ciliary beating. Our investigations revealed that CSF flow is confined within individual ventricular cavities, with little exchange of fluid between ventricles, despite a pulsatile CSF displacement caused by the heartbeat. Interestingly, our results showed that the ventricular boundaries supporting this compartmentalized CSF flow are abolished during bodily movement, highlighting that multiple physiological processes regulate the hydrodynamics of CSF flow. Finally, we showed that perturbing cilia reduces hydrodynamic coupling between the brain ventricles and disrupts ventricular development. We propose that motile-cilia-generated flow is crucial in regulating the distribution of CSF within and across brain ventricles. Spatially organized motile cilia with rotational beats create directional CSF flow Ciliary beating, heartbeat, and locomotion generate distinct components of CSF flow Joint action of these components balances CSF compartmentalization and dispersion Disruption of ciliary beating leads to ventricular defects during brain development
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Affiliation(s)
- Emilie W Olstad
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway
| | - Christa Ringers
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway
| | - Jan N Hansen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway; Institute of Innate Immunity, Department of Biophysical Imaging, University Hospital, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany
| | - Adinda Wens
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway
| | - Cecilia Brandt
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway
| | - Dagmar Wachten
- Institute of Innate Immunity, Department of Biophysical Imaging, University Hospital, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, St. Olavs University Hospital, Edvard Griegs Gate 8, 7030 Trondheim, Norway.
| | - Nathalie Jurisch-Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, The Faculty of Medicine, Norwegian University of Science and Technology, Olav Kyrres Gate 9, 7030 Trondheim, Norway; Department of Neurology and Clinical Neurophysiology, St. Olavs University Hospital, Edvard Griegs Gate 8, 7030 Trondheim, Norway.
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20
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Balbach M, Beckert V, Hansen JN, Wachten D. Shedding light on the role of cAMP in mammalian sperm physiology. Mol Cell Endocrinol 2018; 468:111-120. [PMID: 29146556 DOI: 10.1016/j.mce.2017.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/10/2017] [Accepted: 11/10/2017] [Indexed: 12/24/2022]
Abstract
Mammalian fertilization relies on sperm finding the egg and penetrating the egg vestments. All steps in a sperm's lifetime crucially rely on changes in the second messenger cAMP (cyclic adenosine monophosphate). In recent years, it has become clear that signal transduction in sperm is not a continuum, but rather organized in subcellular domains, e.g. the sperm head and the sperm flagellum, with the latter being further separated into the midpiece, principal piece, and endpiece. To understand the underlying signaling pathways controlling sperm function in more detail, experimental approaches are needed that allow to study sperm signaling with spatial and temporal precision. Here, we will give a comprehensive overview on cAMP signaling in mammalian sperm, describing the molecular players involved in these pathways and the sperm functions that are controlled by cAMP. Furthermore, we will highlight recent advances in analyzing and manipulating sperm signaling with spatio-temporal precision using light.
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Affiliation(s)
- Melanie Balbach
- Center of Advanced European Studies and Research (caesar), Department of Molecular Sensory Systems, Bonn, Germany
| | - Vera Beckert
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Jan N Hansen
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, University Hospital, University of Bonn, Bonn, Germany; Center of Advanced European Studies and Research (caesar), Minerva Max Planck Research Group, Molecular Physiology, Bonn, Germany.
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21
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Reichenbach N, Delekate A, Breithausen B, Keppler K, Poll S, Schulte T, Peter J, Plescher M, Hansen JN, Blank N, Keller A, Fuhrmann M, Henneberger C, Halle A, Petzold GC. P2Y1 receptor blockade normalizes network dysfunction and cognition in an Alzheimer's disease model. J Exp Med 2018; 215:1649-1663. [PMID: 29724785 PMCID: PMC5987918 DOI: 10.1084/jem.20171487] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 02/12/2018] [Accepted: 04/12/2018] [Indexed: 11/04/2022] Open
Abstract
Astrocytic hyperactivity is an important contributor to neuronal-glial network dysfunction in Alzheimer's disease (AD). We have previously shown that astrocyte hyperactivity is mediated by signaling through the P2Y1 purinoreceptor (P2Y1R) pathway. Using the APPPS1 mouse model of AD, we here find that chronic intracerebroventricular infusion of P2Y1R inhibitors normalizes astroglial and neuronal network dysfunction, as measured by in vivo two-photon microscopy, augments structural synaptic integrity, and preserves hippocampal long-term potentiation. These effects occur independently from β-amyloid metabolism or plaque burden but are associated with a higher morphological complexity of periplaque reactive astrocytes, as well as reduced dystrophic neurite burden and greater plaque compaction. Importantly, APPPS1 mice chronically treated with P2Y1R antagonists, as well as APPPS1 mice carrying an astrocyte-specific genetic deletion (Ip3r2-/-) of signaling pathways downstream of P2Y1R activation, are protected from the decline of spatial learning and memory. In summary, our study establishes the restoration of network homoeostasis by P2Y1R inhibition as a novel treatment target in AD.
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Affiliation(s)
| | | | - Björn Breithausen
- Institute of Cellular Neurosciences, University Hospital Bonn, Bonn, Germany
| | - Kevin Keppler
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stefanie Poll
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Jan Peter
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Jan N Hansen
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Nelli Blank
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Armin Keller
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | | | - Christian Henneberger
- German Center for Neurodegenerative Diseases, Bonn, Germany.,Institute of Cellular Neurosciences, University Hospital Bonn, Bonn, Germany.,Institute of Neurology, University College London, London, England, UK
| | - Annett Halle
- German Center for Neurodegenerative Diseases, Bonn, Germany.,Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases, Bonn, Germany .,Department of Neurology, University Hospital Bonn, Bonn, Germany
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22
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Brueckner M, Hansen JN, Gu L, Lee S, Reichenbach N, Petzold GC, Mueller CE, Halle A. O2‐07‐01: Perturbed Purinergic Signaling Causes Dysfunction of Plaque‐Associated Microglia in a Mouse Model of Alzheimer's Disease. Alzheimers Dement 2016. [DOI: 10.1016/j.jalz.2016.06.430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | - Jan N. Hansen
- Center of Advanced European Studies and ResearchBonnGermany
| | - Ligang Gu
- Center of Advanced European Studies and ResearchBonnGermany
| | | | | | | | | | - Annett Halle
- Center of Advanced European Studies and ResearchBonnGermany
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23
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Abstract
Subtilin is an antimicrobial peptide of the lantibiotic family that is produced by Gram-positive Bacillus subtilis, and its biosynthesis involves expression of presubtilin which consists of a leader segment and a mature segment. The leader segment is unlike a typical sec-type general secretion signal, and its ability to mediate translocation through a non-sec pathway has been previously studied by fusing the subtilin leader to an alkaline phosphatase reporter and expressing it in B. subtilis 168 [Izaguirre, G. and Hansen, J. N. (1997) Appl. Environ. Microbiol. 63, 3965-3971]. In this work, we have expressed the same subtilin leader-AP fusion in Gram-negative Escherichia coli, and found that the AP polypeptide is translocated into the periplasmic compartment and assembles into an enzymatically active form. The subtilin leader segment was not cleaved from this enzymatically active AP, which remained associated with the membrane. Conversion of the cells to spheroplasts followed by treatment with proteinase K showed that about 50% of the bound AP was sufficiently exposed on the surface of the spheroplasts to be inactivated by proteolytic cleavage.
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Affiliation(s)
- L K Paul
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, USA
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24
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Paik SH, Chakicherla A, Hansen JN. Identification and characterization of the structural and transporter genes for, and the chemical and biological properties of, sublancin 168, a novel lantibiotic produced by Bacillus subtilis 168. J Biol Chem 1998; 273:23134-42. [PMID: 9722542 DOI: 10.1074/jbc.273.36.23134] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.2] [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: 11/06/2022] Open
Abstract
An antimicrobial peptide produced by Bacillus subtilis 168 was isolated and characterized. It was named sublancin 168, and its behavior during Edman sequence analysis and its NMR spectrum suggested that sublancin is a dehydroalanine-containing lantibiotic. A hybridization probe based on the peptide sequence was used to clone the presublancin gene, which encoded a 56-residue polypeptide consisting of a 19-residue leader segment and a 37-residue mature segment. The mature segment contained one serine, one threonine, and five cysteine residues. Alkylation of mature sublancin showed no free sulfhydryl groups, suggesting that one sulfydryl had formed a beta-methyllanthionine bridge with a dehydrobutyrine derived by posttranslational modification of threonine; with the other four cysteines forming two disulfide bridges. It is unprecedented for a lantibiotic to contain a disulfide bridge. The sublancin leader was similar to known type AII lantibiotics, containing a double-glycine motif that is typically recognized by dual-function transporters. A protein encoded immediately downstream from the sublancin gene possessed features of a dual-function ABC transporter with a proteolytic domain and an ATP-binding domain. The antimicrobial activity spectrum of sublancin was like other lantibiotics, inhibiting Gram-positive bacteria but not Gram-negative bacteria; and like the lantibiotics nisin and subtilin in its ability to inhibit both bacterial spore outgrowth and vegetative growth. Sublancin is an extraordinarily stable lantibiotic, showing no degradation or inactivation after being stored in aqueous solution at room temperature for 2 years. The fact that sublancin is a natural product of B. subtilis 168, for which a great deal of genetic information is available, including the entire sequence of its genome, suggests that sublancin will be an especially good model for studying the potential of lantibiotics as sources of novel biomaterials.
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Affiliation(s)
- S H Paik
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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25
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Izaguirre G, Hansen JN. Use of alkaline phosphatase as a reporter polypeptide to study the role of the subtilin leader segment and the SpaT transporter in the posttranslational modifications and secretion of subtilin in Bacillus subtilis 168. Appl Environ Microbiol 1997; 63:3965-71. [PMID: 9327561 PMCID: PMC168708 DOI: 10.1128/aem.63.10.3965-3971.1997] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The subtilin leader segment of presubtilin was fused to alkaline phosphatase (AP), which was used as a reporter polypeptide to study the role of the subtilin leader segment in posttranslational modifications during the conversion of presubtilin to subtilin and in the translocation of presubtilin from the cytoplasm of Bacillus subtilis 168 to the extracellular medium. It was observed that the subtilin leader segment could be utilized by a wild-type transporter, but secretion was enhanced if the subtilin transporter was available. The subtilin leader was not cleaved away from the AP component of the precursor until the precursor had been transported to the cell wall, and none of the AP was released into the medium until after cleavage had occurred. The role of SpaT, which is an ABC transporter that has been implicated in subtilin secretion, was explored by making a large in-frame deletion from the central region of SpaT and observing the effect on translocation of the AP reporter. Instead of having an effect on translocation, the deletion disrupted proteolytic cleavage of the subtilin leader segment and release of the AP reporter into the medium. The AP that was secreted by means of the subtilin leader segment had not undergone any posttranslational modifications, as assessed by amino acid composition analysis and enzymatic activity analysis.
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Affiliation(s)
- G Izaguirre
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, USA
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26
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Abstract
The ability to respond to osmotic stress by osmoregulation is common to virtually all living cells. Gram-negative bacteria such as Escherichia coli and Salmonella typhimurium can achieve osmotolerance by import of osmoprotectants such as proline and glycine betaine by an import system encoded in an operon called proU with genes for proteins ProV, ProW, and ProX. In this report, we describe the discovery of a proU-type locus in the gram-positive bacterium Bacillus subtilis. It contains four open reading frames (ProV, ProW, ProX, and ProZ) with homology to the gram-negative ProU proteins, with the B. subtilis ProV, ProW, and ProX proteins having sequence homologies of 35, 29, and 17%, respectively, to the E. coli proteins. The B. subtilis ProZ protein is similar to the ProW protein but is smaller and, accordingly, may fulfill a novel role in osmoprotection. The B. subtilis proU locus was discovered while exploring the chromosomal sequence upstream from the spa operon in B. subtilis LH45, which is a subtilin-producing mutant of B. subtilis 168. B. subtilis LH45 had been previously constructed by transformation of strain 168 with linear DNA from B. subtilis ATCC 6633 (W. Liu and J. N. Hansen, J. Bacteriol. 173:7387-7390, 1991). Hybridization experiments showed that LH45 resulted from recombination in a region of homology in the proV gene, so that the proU locus in LH45 is a chimera between strains 168 and 6633. Despite being a chimera, this proU locus was fully functional in its ability to confer osmotolerance when glycine betaine was available in the medium. Conversely, a mutant (LH45 deltaproU) in which most of the proU locus had been deleted grew poorly at high osmolarity in the presence of glycine betaine. We conclude that the proU-like locus in B. subtilis LH45 is a gram-positive counterpart of the proU locus in gram-negative bacteria and probably evolved prior to the evolutionary split of prokaryotes into gram-positive and gram-negative forms.
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Affiliation(s)
- Y Lin
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, USA
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27
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Chakicherla A, Hansen JN. Role of the leader and structural regions of prelantibiotic peptides as assessed by expressing nisin-subtilin chimeras in Bacillus subtilis 168, and characterization of their physical, chemical, and antimicrobial properties. J Biol Chem 1995; 270:23533-9. [PMID: 7559517 DOI: 10.1074/jbc.270.40.23533] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [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: 01/25/2023] Open
Abstract
Biosynthesis of lantibiotics such as nisin and subtilin involves post-translational modifications, including dehydration of serines and threonines, formation of thioether cross-linkages, translocation, cleavage of a leader sequence, and release into the medium. We have studied the cellular machinery that performs the modifications by constructing and expressing nisin-subtilin chimeric prepeptides in a strain of Bacillus subtilis 168 that possesses all of the cellular machinery for making subtilin except for the presubtilin gene. The chimeras consisted of a normal subtilin leader region (SL), fused to nisin-subtilin chimeric structural regions, one of which was SL-Nis1-11-Sub12-32, in which the N-terminal portion of the structural region was derived from nisin, and the C-terminal portion derived from subtilin. This chimera was accurately and efficiently converted to the corresponding mature lantibiotic, as established by reverse phase high performance liquid chromatography profiles, proton NMR spectroscopy, mass spectral analysis, and biological activity. A succinylated form of the chimera was also produced. Another chimera was in the reverse sense, with subtilin sequence at the N terminus and nisin sequence at the C terminus of the structural region (SL-Sub1-11-Nis12-34). It was processed into a heterogeneous mixture of products, none of which had the characteristics of a correctly processed polypeptide, but did contain a minor component that was active, with a specific activity that considerably exceeded nisin itself. These results, together with results published earlier, establish that processing requires specific recognition between the prelantibiotic peptide and the processing machinery, and in order for the processing to occur correctly, there must be an appropriate combination of the N-terminal part of the leader region and the C-terminal part of the structural region of the prepeptide.
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Affiliation(s)
- A Chakicherla
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742, USA
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28
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Abstract
Nisin is a ribosomally synthesized peptide that has broad-spectrum antibacterial activity, including activity against many bacteria that are food-spoilage pathogens. Nisin is produced as a fermentation product of a food-grade bacterium, and the safety and efficacy of nisin as a food preservative have resulted in its widespread use throughout the world, including the U.S. Nisin is a member of the class of antimicrobial substances known as lantibiotics, so called because they contain the unusual amino acid lanthionine. Lantibiotics, in general, have considerable promise as food preservatives, although only nisin has been sufficiently well characterized to be used for this purpose. As the number of known natural lantibiotics has increased and their useful characteristics have been explored, it has become desirable to synthesize structural analogs of nisin and other lantibiotics that do not occur naturally. The fact that lantibiotics are gene-encoded peptides synthesized by transcription and translation allows structural variants to be generated by mutagenesis. This review focuses on the progress that has been made in the construction and biological expression of genetically engineered nisin structural analogs. For example, a host-vector pair has been engineered that permits the construction of mutants of the structural gene for subtilin, which is a naturally occurring structural analog of nisin. The vector is designed in such a way that the mutant gene can be substituted for the natural subtilin gene in the chromosome of Bacillus subtilis, which in turn directs the transcription, translation, posttranslational modifications, and secretion of the mature form of the structural analog. Several structural analogs have been constructed, and their properties have provided insight into some of the structure-function relationships in lantibiotics, as well as their mechanism of antimicrobial action. These advances are assessed together with potential problems in the future development of nisin analogs as valuable new food preservatives.
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Affiliation(s)
- J N Hansen
- Department of Chemistry and Biochemistry, College of Life Sciences, University of Maryland, College Park 20742-2021
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29
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Abstract
Peptides that have antimicrobial activity are synthesized by many prokaryotic and eukaryotic organisms. Antimicrobial peptides commonly contain unusual amino acids that contribute to their properties and functions. Although bacteria synthesize most of these peptides by nonribosomal mechanisms, this review focuses on those that are synthesized by pathways that involve posttranslational modification of ribosomally synthesized precursor peptides. A particularly interesting class of these antimicrobial peptides is the lantibiotics, of which nisin and subtilin are the longest-known examples, although nearly a dozen new lantibiotics have been discovered in recent years. The fact that the lantibiotic structures are derived from gene-encoded peptides means that structural analogs of natural lantibiotics can be constructed by mutagenesis of their structural genes. Recent advances in our understanding of the molecular genetics of lantibiotics has made the construction of novel lantibiotics with enhanced chemical and antimicrobial properties possible. This review describes these advances and proposes future trends of research, as well as potential application of engineered lantibiotics, in the context of the general field of antimicrobial peptides.
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Affiliation(s)
- J N Hansen
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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30
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Liu W, Hansen JN. The antimicrobial effect of a structural variant of subtilin against outgrowing Bacillus cereus T spores and vegetative cells occurs by different mechanisms. Appl Environ Microbiol 1993; 59:648-51. [PMID: 8434932 PMCID: PMC202163 DOI: 10.1128/aem.59.2.648-651.1993] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [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: 01/30/2023] Open
Abstract
Subtilin is a ribosomally synthesized antimicrobial peptide that contains several unusual amino acids as a result of posttranslational modifications. Site-directed mutagenesis was employed to construct a structural variant of subtilin in which the unusual dehydroalanine (Dha) residue at position 5 was changed to alanine. Proton nuclear magnetic resonance spectroscopy, amino acid composition, and N-terminal sequence analysis established that the mutation did not disrupt posttranslational processing of the precursor peptide. This mutant subtilin was devoid of antimicrobial activity as assessed by its lack of inhibitory effects on outgrowth of Bacillus cereus T spores. However, this same mutant subtilin was fully active with respect to its ability to induce lysis of vegetative B. cereus T cells. Because an intact Dha-5 residue is required in the one instance but not in the other, it was concluded that the molecular mechanism by which subtilin inhibits (without lysis) spore outgrowth is not the same as the mechanism by which it inhibits (with lysis) vegetative cells.
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Affiliation(s)
- W Liu
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Liu W, Hansen JN. Enhancement of the chemical and antimicrobial properties of subtilin by site-directed mutagenesis. J Biol Chem 1992; 267:25078-85. [PMID: 1460009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Subtilin and nisin are gene-encoded antibiotic peptides that are ribosomally synthesized by Bacillus subtilis and Lactococcus lactis, respectively. Gene-encoded antibiotics are unique in that their structures can be manipulated by mutagenesis of their structural genes. Although subtilin and nisin share considerable structural homology, subtilin has a greater tendency than nisin to undergo spontaneous inactivation. This inactivation is a accompanied by chemical modification of the dehydroalanine at position 5 (DHA5) with a kinetic first-order t1/2 of 0.8 days. It was hypothesized that the R group carboxyl of Glu4 in subtilin participates in the chemical modification of the adjacent DHA5. Noting that nisin has Ile at position 4, site-directed mutagenesis was used to change Glu4 of subtilin to Ile, in order to eliminate this carboxyl-group participation. The DHA5 of this mutant subtilin (E4I-subtilin) underwent modification with a t1/2 of 48 days, which is 57-fold slower than natural subtilin, and the rate of loss of biological activity dropped by a like amount. These results suggest that an intact DHA5 is critical for subtilin activity against bacterial spore outgrowth. A double mutant of subtilin, in which the DHA5 residue of E4I-subtilin was mutated to Ala was devoid of detectable inhibition against spore outgrowth. The specific activity of E4I-subtilin was 3-4-fold higher than natural subtilin, suggesting that an increase in the hydrophobicity of the N-terminal end of the molecule enhances activity. These are the first mutants of subtilin that have been reported, and E4I-subtilin is the first example of any lantibiotic whose properties have been improved by mutagenesis. In order to carry out the mutagenesis, a host-vector pair was constructed that permits a deletion replacement in which the natural subtilin gene is replaced by the mutant gene at the normal location in the chromosome. This maintains normal gene dosage and regulatory responses, as well as eliminates ambiguities caused by expression of the normal and mutant genes in the same cell.
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Affiliation(s)
- W Liu
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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32
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Abstract
An 851-residue open reading frame (ORF) called SpaE has been discovered in the subtilin (spa) operon. Interruption of this ORF with a chloramphenicol acetyltransferase gene destroys the ability of Bacillus subtilis LH45 delta c (a derivative of B. subtilis 168) to produce subtilin, which is an antimicrobial peptide belonging to the class of ribosomally synthesized peptide antibiotics called lantibiotics. SpaE shows strong homology to NisB, which is in the nisin (nis) operon in Lactococcus lactis ATCC 11454. Despite the strong sequence homology between SpaE and NisB, the spaE and nisB genes occupy very different locations in their respective operons, indicating that they have been evolving separately for a long time. Primer extension analysis was employed to identify a promoter upstream from the spaE gene, which appears to define the 5' end of the spa operon, which contains four other ORFs (Y. J. Chung, M. T. Steen, and J. N. Hansen, J. Bacteriol. 174:1417-1422, 1992).
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Affiliation(s)
- Y J Chung
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Chung YJ, Steen MT, Hansen JN. The subtilin gene of Bacillus subtilis ATCC 6633 is encoded in an operon that contains a homolog of the hemolysin B transport protein. J Bacteriol 1992; 174:1417-22. [PMID: 1735728 PMCID: PMC206441 DOI: 10.1128/jb.174.4.1417-1422.1992] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sequence analysis upstream from the subtilin structural gene (spaS) in Bacillus subtilis ATCC 6633 revealed several open reading frames, SpaB, SpaC, and SpaD. SpaB, consisting of 599 amino acid residues, shows excellent homology with a variety of membrane translocator proteins, such as HlyB from Escherichia coli and some mammalian multidrug resistance proteins. When the spaB gene was interrupted by integration of a chloramphenicol acetyltransferase gene, the ability of the cell to produce subtilin, as determined by a halo assay, was lost. The homology of SpaB to translocator proteins, including transmembrane and ATP-binding regions, suggests that SpaB may play a role in subtilin secretion. The SpaB open reading frame overlaps with another open reading frame called SpaC, and the possibility that the SpaB and SpaC proteins become fused by frameshifting is considered. Regions of homology between SpaD (177 residues) and HlyD were also found, suggesting that SpaD may participate with SpaB in translocation of subtilin through the membrane. Although no readily interpretable homologies to SpaC (442 residues) were found, its sequence suggests that it is membrane associated. The absence of rho-independent transcription terminators between these open reading frames suggests that they are all part of the same operon.
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Affiliation(s)
- Y J Chung
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Abstract
Subtilin is a ribosomally synthesized peptide antibiotic produced by Bacillus subtilis ATCC 6633. B. subtilis 168 was converted to a subtilin producer by competence transformation with chromosomal DNA from B. subtilis ATCC 6633. A chloramphenicol acetyltransferase gene was inserted next to the subtilin structural gene as a selectable marker. The genes that conferred subtilin production were derived from a 40-kb region of the B. subtilis ATCC 6633 chromosome that had flanking homologies to the B. subtilis 168 chromosome. The subtilin produced by the mutant was identical to natural subtilin in its biological activity, chromatographic behavior, amino acid composition, and N-terminal amino acid sequence.
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Affiliation(s)
- W Liu
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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35
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Lai SP, Watson JC, Hansen JN, Sze H. Molecular cloning and sequencing of cDNAs encoding the proteolipid subunit of the vacuolar H(+)-ATPase from a higher plant. J Biol Chem 1991; 266:16078-84. [PMID: 1831453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
To understand the molecular structure of the vacuolar H(+)-translocating ATPase from plants, cDNAs encoding the N,N'-dicyclohexylcarbodiimide-binding 16-kDa proteolipid from oat (Avena sativa L. var. Lang) have been obtained. A synthetic oligonucleotide corresponding to a region of the bovine proteolipid cDNA (Mandel, M., Moriyama, Y., Hulmes, J.D., Pan, Y.-C.E., Nelson, H., and Nelson, N. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 5521-5524) was used to screen an oat cDNA library constructed in lambda gt11. The nucleotide sequences of several positive clones (VATP-P1, clones 12, 54, 93) demonstrated the presence of a small multigene family. The four clones showed extensive divergence in their codon usage and their 3'-untranslated regions; however, the deduced amino acid sequences of the proteins were 97-99% identical. These clones encoded the proteolipid subunit as one of them (clone 12) expressed a fusion protein that reacted with an antibody to the 16-kDa proteolipid. The open reading frame of one cDNA clone (VATP-P1) predicted a polypeptide of 165 amino acids with a molecular mass of 16,641. Based on hydropathy plots, a molecule with four membrane-spanning domains was predicted, in which domain IV was especially conserved among different species. This domain showed 80% identity in nucleotide or amino acid sequences between the oat and the bovine proteolipids and contained a glutamate residue that is the putative N,N'-dicyclohexylcarbodiimide-binding residue. The presence of a small multigene family of the 16-kDa proteolipid was confirmed by Southern blot analysis showing that several distinct restriction fragments of oat nuclear DNA hybridized with the VATP-P1 cDNA.
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Affiliation(s)
- S P Lai
- Department of Botany, University of Maryland, College Park 20742
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Steen MT, Chung YJ, Hansen JN. Characterization of the nisin gene as part of a polycistronic operon in the chromosome of Lactococcus lactis ATCC 11454. Appl Environ Microbiol 1991; 57:1181-8. [PMID: 1905517 PMCID: PMC182865 DOI: 10.1128/aem.57.4.1181-1188.1991] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.2] [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: 12/29/2022] Open
Abstract
The location and organization of the nisin locus in Lactococcus lactis ATCC 11454 were studied. Primer extension of in vivo mRNA transcripts of the gene that encodes the nisin prepropeptide sequence indicated the presence of a promoter at least 4 kb upstream from the nisin gene and that the mRNA has several processing sites. Restriction fragment patterns using rare-cutting enzymes, orthogonal pulsed-field clamped homogeneous electric field (CHEF) agarose gel electrophoresis, and hybridization with nisin gene probes showed that the nisin prepropeptide gene was located on a megabase-size restriction fragment, which was taken as proof of a chromosomal location. This is contrary to earlier reports, which had indicated that genes for nisin production were located on plasmids. There was no evidence of more than one chromosomal location or more than one copy of the nisin gene. The restriction patterns indicated that the size of the L. lactis genome is about 2,500 kb. The previously observed (G. W. Buchman, S. Banerjee, and J. N. Hansen, J. Biol. Chem. 263: 16260-16266, 1988) downstream open reading frame (ORF) was fully sequenced to reveal an 851-amino-acid coding region, an upstream putative mRNA processing site, and a putative rho-independent terminator. The ORF was analyzed for secondary structural features, and the sequence data bases were searched for homologies. The ORF contained many amphipathic helices, a C-terminal transmembrane helix, and homologies to some membrane-associated proteins. It lacked an N-terminal membrane insertion sequence and accordingly appears to be associated with, and anchored to, the cytoplasmic side of the membrane. An additional ORF that possessed a ribosome-binding sequence and tandem promoters, indicating the beginning of a new operon, was identified still farther downstream. The results were consistent with the nisin gene being part of a polycistronic operon with a size greater than 8.5 kb.
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Affiliation(s)
- M T Steen
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Abstract
Nisin is a small gene-encoded antimicrobial protein produced by Lactococcus lactis that contains unusual dehydroalanine and dehydrobutyrine residues. The reactivity of these residues toward nucleophiles was explored by reacting nisin with a variety of mercaptans. The kinetics of reaction with 2-mercaptoethane-sulfonate and thioglycolate indicated that the reaction pathway includes a binding step. Reaction of nisin at high pH resulted in the formation of multimeric products, apparently as a result of intramolecular and intermolecular reactions between nucleophilic groups and the dehydro residues. One of the nucleophiles had a pKa of about 9.8. The unique vinyl protons of the dehydro residues that give readily identifiable proton nuclear magnetic resonances were used to observe the addition of nucleophiles to the dehydro moiety. After reaction with nucleophiles, nisin lost its antibiotic activity and no longer showed the dehydro resonances, indicating that the dehydro groups had been modified. The effect of pH on the solubility of nisin was determined; the solubility was quite high at low pH (57 mg/ml at pH 2) and was much lower at high pH (0.25 mg/ml at pH 8 to 12), as measured before significant pH-induced chemical modification had occurred. High-performance liquid chromatography on a C18 column was an effective technique for separating unmodified nisin from its reaction products. The cyanogen bromide cleavage products of nisin were about 90% less active toward inhibition of bacterial spore outgrowth than was native nisin. These results are consistent with earlier observations, which suggested that the dehydro residues of nisin have a role in the mechanism of antibiotic action, in which they act as electrophilic Michael acceptors toward nucleophiles in the cellular target.
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Affiliation(s)
- W Liu
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Steen MT, Kaper JM, Pleij CW, Hansen JN. In-vitro translation of cucumoviral satellites. III. Translational efficiencies of cucumber mosaic virus-associated RNA 5 sequence variants can be related to the predicted secondary structures of their first 55 nucleotides. Virus Genes 1990; 4:41-52. [PMID: 1697436 DOI: 10.1007/bf00308564] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The cucumber mosaic virus (CMV) satellites D- and S-CARNA 5 (CARNA 5 = Cucumber mosaic virus-Associated RNA 5), their full-length cDNA clone transcripts, and DNA clone transcripts of their open reading frames (ORFs) were used as mRNAs in the wheat-germ in-vitro translation system. Natural D-CARNA 5 yielded an anomalously large polypeptide, while transcripts made from cDNA clones of D-CARNA 5 or its first ORF had no mRNA activity. Transcripts made from the second major ORF in D-CARNA 5 yielded a smaller product, consistent with its size. Natural S-CARNA 5 and its cDNA clone transcripts both yielded the two polypeptides previously reported, while transcripts of its only major ORF yielded exclusively the smaller of the two products. The potential for an alternate initiation codon, 36 nucleotides upstream, being the source of the larger of the two polypeptides was tested. The differences in the translational properties of D- and S-CARNA 5 were related to the predicted secondary structures of the first 55 nucleotides in these CARNA 5 sequence variants. The calculated free energies of the predicted hairpins correlated inversely with their in-vitro translational activities.
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Affiliation(s)
- M T Steen
- Microbiology and Plant Pathology Laboratory, A.R.S., U.S.D.A., Beltsville, MD 20705
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Madsen JK, Pedersen F, Amtoft A, Deding A, Grande P, Hansen JN, Hilden M, Hornum I, Jensen T, Lindskov J. [Reduction of mortality in acute myocardial infarction with streptokinase and aspirin therapy. Results of ISIS-2]. Ugeskr Laeger 1989; 151:2565-9. [PMID: 2683281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This investigation includes 17,187 patients in 417 hospitals in 16 countries admitted within 24 hours of the commencement of symptoms of acute myocardial infarction (AMI). The patients were allotted at random to the following treatments 1) intravenous infusion of 1.5 million International Units streptokinase (SK) during one hour, 2) 160 mg acetyl salicylic acid (ASA) daily for 30 days, 3) both SK and ASA and 4) placebo treatment only. The five-week cardiovascular mortality was reduced by 25% following infusion of streptokinase from 12.0% to 9.2% and by 23% during ASA treatment from 11.8% to 9.4%. The combination of SK and ASA resulted in 42% reduction in the cardiovascular mortality after five weeks compared with the placebo. The effect of SK was greatest if treatment was instituted within six hours but effects were obtained after all of the first 24 hours. The preliminary results show that the reduction in mortality obtained by both SK and ASA appears to continue during the subsequent one to two years. SK treatment resulted in haemorrhage requiring treatment in 0.5% as compared with 0.2% in the placebo group, more cases of proved cerebral haemorrhage, 0.1% as compared with 0.0%, but fewer cases of cerebral apoplexy, 0.7% as compared with 0.8%. It is concluded that thrombolysis with SK combined with prophylaxis of repeated thrombosis with ASA is the indicated treatment in cases of AMI and less than 6-24 hours duration.
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Buchman GW, Banerjee S, Hansen JN. Structure, expression, and evolution of a gene encoding the precursor of nisin, a small protein antibiotic. J Biol Chem 1988; 263:16260-6. [PMID: 3141403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We have cloned and sequenced a gene (spaN) from Streptococcus lactis ATCC 11454 which encodes the peptide precursor of the small protein antibiotic nisin. The encoded precursor is 57 amino acids long, with a 23-residue leader region and a 34-residue structural region. The structural region contains serines, threonines, and cysteines at exactly the positions required to give mature nisin by a series of post-translational modifications involving dehydration of serines and threonines to dehydro forms, and cross-linking with cysteine residues. S1 mapping revealed a 267-nucleotide transcript of the nisin gene that is expressed during vegetative growth and stationary phase. It has a half-life of 7-10 min. The absence of an identifiable promoter or rho-independent terminator and the detection of two different 5'-ends of the transcript suggested it is a processing product from a larger RNA. This may represent a polycistronic mRNA which may also encode proteins involved in processing the nisin precursor peptide. Open reading frames were found in regions flanking the nisin gene. The one downstream had a ribosome binding site and appeared to be transcribed by read-through from the nisin gene. The one upstream had significant homology to a putative transposase from the Escherichia coli IS2 insertion element. Comparison of gene sequence homologies between nisin and the other lanthionine antibiotics, subtilin and epidermin, indicated that they all evolved from a common ancestor. Corresponding leader peptide sequences showed mediocre amino acid homology, but nearly perfect hydropathic homologies, suggesting a common function. It is proposed that this function includes recognition signals or other information required for post-translational processing.
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Affiliation(s)
- G W Buchman
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Vold BS, Green CJ, Narasimhan N, Strem M, Hansen JN. Transcriptional analysis of Bacillus subtilis rRNA-tRNA operons. II. Unique properties of an operon containing a minor 5 S rRNA gene. J Biol Chem 1988; 263:14485-90. [PMID: 3139657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
This is part of a series of two papers on gene regulation in Bacillus subtilis rRNA-tRNA operons that contain large clusters of tRNA genes. The preceding paper (Vold, B.S., Okamoto, K., Murphy, B.J., and Green, C.J. (1988) J. Biol. Chem. 263, 14480-14484) investigates the rrnB operon containing 21 tRNA genes, and this paper investigates a B. subtilis rRNA-tRNA operon containing 16 tRNA genes and a minor 5 S rRNA. Hybridization studies suggest this minor 5 S rRNA occurs as a single copy in the B. subtilis 168 genome. S1 nuclease mapping indicates that this minor 5 S rRNA gene has its own promoter. No promoters have been found immediately 5' to any of the major 5 S rRNA species in B. subtilis rRNA operons. S1 mapping of the spacer region between the 23 S and minor 5 S rRNA revealed that the maturation of the 23 S rRNA in this operon may arise from an unusual processing mechanism. S1 nuclease mapping experiments suggest the existence of a promoter element immediately upstream of the last gene, for tRNA(Leu CAA), in the operon. A precursor leucine tRNA resulting from transcription of this last tRNA gene was observed in Northern hybridizations, and the amounts of this precursor increased during sporulation. A single terminator-like element is located just upstream of this last tRNA gene; however, S1 nuclease mapping experiments suggest that some read-through transcription occurs. Thus, all 16 tRNA genes are under control of the upstream 16 S rRNA promoters and the minor 5 S rRNA promoter. However, the last tRNA gene is primarily under the control of its own unique promoter.
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Affiliation(s)
- B S Vold
- Department of Molecular Biology, SRI International, Menlo Park, California 94025
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Jouvin-Marche E, Cuddihy A, Butler S, Hansen JN, Fitch WM, Rudikoff S. Modern evolution of a single-copy gene: the immunoglobulin C kappa locus in wild mice. Mol Biol Evol 1988; 5:500-11. [PMID: 3143045 DOI: 10.1093/oxfordjournals.molbev.a040514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The immunoglobulin kappa light-chain constant region gene (C kappa) has been cloned and sequenced from five wild mouse species. Analysis of these data has permitted an assessment of single-copy gene evolution during a limited time period as defined by the genus Mus. Sequence conservation was found to be as high (or higher) in the 5' and enhancer regions as in the coding region. The pattern of substitutions throughout these genes suggests that parallel evolution has occurred frequently and that substitutions at replacement sites have not decreased significantly, owing to saturation during this period of approximately 10 Myr. Phylogenetic relationships have been determined among these wild species as well as among members of the genus Rattus.
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Affiliation(s)
- E Jouvin-Marche
- Laboratory of Genetics, National Cancer Institute, Bethesda, Maryland 20892
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Banerjee S, Hansen JN. Structure and expression of a gene encoding the precursor of subtilin, a small protein antibiotic. J Biol Chem 1988; 263:9508-14. [PMID: 2837490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A gene has been cloned from Bacillus subtilis ATCC 6633 that encodes a 56-residue peptide precursor for the 32-residue peptide antibiotic, subtilin. The precursor contains serines, threonines, and cysteines at positions that permit them to undergo a series of dehydration and cross-linking steps to give the mature antibiotic peptide which contains the unusual amino acids lanthionine, beta-methyllanthionine, D-alanine, dehydroalanine, and dehydrobutyrine. The precursor peptide contains a leader region that has an unusual hydropathic character for an exported protein. The subtilin gene is expressed from a monocistronic transcriptional unit as identified by S1 mapping of the gene transcript. The (-35) region of the promoter is not typical of Bacillus subtilis vegetatively-expressed genes. The subtilin transcript was present in very low amounts during exponential growth, but in large amounts during stationary phase; at which time mature subtilin peptide and antibiotic activity were also observed. The subtilin transcript contains a cleavage-sensitive region that overlaps the ribosome binding site. The primary transcript has an unusually long half-life of about 45 min. These observations confirm that subtilin is derived from a small protein that is synthesized on ribosomes.
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Affiliation(s)
- S Banerjee
- Department of Chemistry and Biochemistry, University of Maryland, College Park 20742
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Shweni PM, Bishop BB, Hansen JN, Subrayen KT. Severe secondary postpartum haemorrhage after caesarean section. S Afr Med J 1987; 72:617-9. [PMID: 3500522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Between January 1982 and April 1985 13 patients with severe secondary postpartum haemorrhage after caesarean section were seen at King Edward VIII Hospital, Durban. The bleeding occurred in the second, third and fourth weeks after delivery, but there were no maternal deaths. Eight of these patients were treated by total abdominal hysterectomy and 1 by revision of the uterine wound and ligation of the bleeding uterine vessels. The last 4 patients, seen in 1985, were treated by selective transcatheter embolisation with Gelfoam pledgets. This method was successful in 3 patients and failed in 1. It is suggested that the latter method has a place in the treatment of these patients.
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Affiliation(s)
- P M Shweni
- Department of Obstetrics and Gynaecology, University of Natal
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46
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Robertson DE, Smith W, Moye MA, Brinsden PR, Hansen JN, Lewis PM, Serhal P, Simons EG, Craft IL. Reduction of ectopic pregnancy by injection under ultrasound control. Lancet 1987; 1:974-5. [PMID: 2882358 DOI: 10.1016/s0140-6736(87)90315-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Abstract
The mechanism by which nitrite inhibits outgrowing spores of Bacillus cereus T was examined by using techniques developed earlier for nitrite analogs. The morphological stage of inhibition, cooperativity effects, effect of pH on inhibition, kinetics of protection against iodoacetate incorporation into membrane sulfhydryl groups, and protection against the bacteriocidal effect of carboxymethylation by iodoacetate indicate that nitrite acts as a membrane-directed sulfhydryl agent. The mechanism by which nitrite modifies the chemical reactivity of the sulfhydryl group could be either direct covalent modification or inactivation through communication with another modified membrane component. Profiles of pH effects suggest that the active agent is the protonated form of nitrite. The nitrite concentrations which modify membrane sulfhydryl activity coincide with those which have a bacteriostatic effect. These results are consistent with membrane sulfhydryl modification as a component of the mechanism of nitrite-induced bacteriostasis in this aerobic sporeformer.
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48
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Jouvin-Marche E, Cuddihy A, Heller M, Butler S, Hansen JN, Rudikoff S. Evolution of immunologically important genes in the genus Mus. Curr Top Microbiol Immunol 1986; 127:149-56. [PMID: 3089693 DOI: 10.1007/978-3-642-71304-0_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Morris SL, Walsh RC, Hansen JN. Identification and characterization of some bacterial membrane sulfhydryl groups which are targets of bacteriostatic and antibiotic action. J Biol Chem 1984; 259:13590-4. [PMID: 6436249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Covalent modification of sulfhydryl groups which become sensitive toward sulfhydryl agents during germination of Bacillus cereus spores exerts a profound bacteriostatic effect, resulting in outgrowth inhibition. The modified spore components are membrane species of 13,000, 28,000, and 29,000 daltons. Detergent disruption of the membrane inactivated the sulfhydryl groups. A highly sigmoid inhibition curve (n = 11.8) with diamide suggested the participation of closely neighboring sulfhydryl groups. Substate and substrate analogs of the lactose and dicarboxylic acid permeases protected the sulfhydryl groups against modification. Nisin, a 34-residue peptide antibiotic, inhibited spore outgrowth and sulfhydryl modification at a concentration of about 0.1 microM. Since these sulfhydryl groups have been implicated as involved with the bacteriostatic action of nitrite, substances directed toward them may be a useful new class of bacteriostatic agents and antibiotics.
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50
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Morris SL, Walsh RC, Hansen JN. Identification and characterization of some bacterial membrane sulfhydryl groups which are targets of bacteriostatic and antibiotic action. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90734-9] [Citation(s) in RCA: 110] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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