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Kalotay E, Klugmann M, Housley GD, Fröhlich D. Dominant aminoacyl-tRNA synthetase disorders: lessons learned from in vivo disease models. Front Neurosci 2023; 17:1182845. [PMID: 37274211 PMCID: PMC10234151 DOI: 10.3389/fnins.2023.1182845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/05/2023] [Indexed: 06/06/2023] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) play an essential role in protein synthesis, being responsible for ligating tRNA molecules to their corresponding amino acids in a reaction known as 'tRNA aminoacylation'. Separate ARSs carry out the aminoacylation reaction in the cytosol and in mitochondria, and mutations in almost all ARS genes cause pathophysiology most evident in the nervous system. Dominant mutations in multiple cytosolic ARSs have been linked to forms of peripheral neuropathy including Charcot-Marie-Tooth disease, distal hereditary motor neuropathy, and spinal muscular atrophy. This review provides an overview of approaches that have been employed to model each of these diseases in vivo, followed by a discussion of the existing animal models of dominant ARS disorders and key mechanistic insights that they have provided. In summary, ARS disease models have demonstrated that loss of canonical ARS function alone cannot fully account for the observed disease phenotypes, and that pathogenic ARS variants cause developmental defects within the peripheral nervous system, despite a typically later onset of disease in humans. In addition, aberrant interactions between mutant ARSs and other proteins have been shown to contribute to the disease phenotypes. These findings provide a strong foundation for future research into this group of diseases, providing methodological guidance for studies on ARS disorders that currently lack in vivo models, as well as identifying candidate therapeutic targets.
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Affiliation(s)
- Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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Kalotay E, Klugmann M, Housley GD, Fröhlich D. Recessive aminoacyl-tRNA synthetase disorders: lessons learned from in vivo disease models. Front Neurosci 2023; 17:1182874. [PMID: 37274208 PMCID: PMC10234152 DOI: 10.3389/fnins.2023.1182874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 04/17/2023] [Indexed: 06/06/2023] Open
Abstract
Protein synthesis is a fundamental process that underpins almost every aspect of cellular functioning. Intriguingly, despite their common function, recessive mutations in aminoacyl-tRNA synthetases (ARSs), the family of enzymes that pair tRNA molecules with amino acids prior to translation on the ribosome, cause a diverse range of multi-system disorders that affect specific groups of tissues. Neurological development is impaired in most ARS-associated disorders. In addition to central nervous system defects, diseases caused by recessive mutations in cytosolic ARSs commonly affect the liver and lungs. Patients with biallelic mutations in mitochondrial ARSs often present with encephalopathies, with variable involvement of peripheral systems. Many of these disorders cause severe disability, and as understanding of their pathogenesis is currently limited, there are no effective treatments available. To address this, accurate in vivo models for most of the recessive ARS diseases are urgently needed. Here, we discuss approaches that have been taken to model recessive ARS diseases in vivo, highlighting some of the challenges that have arisen in this process, as well as key results obtained from these models. Further development and refinement of animal models is essential to facilitate a better understanding of the pathophysiology underlying recessive ARS diseases, and ultimately to enable development and testing of effective therapies.
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Affiliation(s)
- Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
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Fröhlich D, Kalotay E, von Jonquieres G, Bongers A, Lee B, Suchowerska AK, Housley GD, Klugmann M. Dual-function AAV gene therapy reverses late-stage Canavan disease pathology in mice. Front Mol Neurosci 2022; 15:1061257. [PMID: 36568275 PMCID: PMC9772617 DOI: 10.3389/fnmol.2022.1061257] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
The leukodystrophy Canavan disease is a fatal white matter disorder caused by loss-of-function mutations of the aspartoacylase-encoding ASPA gene. There are no effective treatments available and experimental gene therapy trials have failed to provide sufficient amelioration from Canavan disease symptoms. Preclinical studies suggest that Canavan disease-like pathology can be addressed by either ASPA gene replacement therapy or by lowering the expression of the N-acetyl-L-aspartate synthesizing enzyme NAT8L. Both approaches individually prevent or even reverse pathological aspects in Canavan disease mice. Here, we combined both strategies and assessed whether intracranial adeno-associated virus-mediated gene delivery to a Canavan disease mouse model at 12 weeks allows for reversal of existing pathology. This was enabled by a single vector dual-function approach. In vitro and in vivo biopotency assessment revealed significant knockdown of neuronal Nat8l paired with robust ectopic aspartoacylase expression. Following nomination of the most efficient cassette designs, we performed proof-of-concept studies in post-symptomatic Aspa-null mice. Late-stage gene therapy resulted in a decrease of brain vacuoles and long-term reversal of all pathological hallmarks, including loss of body weight, locomotor impairments, elevated N-acetyl-L-aspartate levels, astrogliosis, and demyelination. These data suggest feasibility of a dual-function vector combination therapy, directed at replacing aspartoacylase with concomitantly suppressing N-acetyl-L-aspartate production, which holds potential to permanently alleviate Canavan disease symptoms and expands the therapeutic window towards a treatment option for adult subjects.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia,*Correspondence: Dominik Fröhlich,
| | - Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Andre Bongers
- Biological Resources Imaging Laboratory, University of New South Wales, Sydney, NSW, Australia
| | - Brendan Lee
- Biological Resources Imaging Laboratory, University of New South Wales, Sydney, NSW, Australia
| | - Alexandra K. Suchowerska
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia,Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany,Matthias Klugmann,
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Perez Ortiz A, Fröhlich D, Gottheil L, Penteado A, Esche E, Repke JU, Schomäcker R. Implementation of Heat‐Integration Concepts for Autothermal Oxidative Coupling of Methane. CHEM-ING-TECH 2022. [DOI: 10.1002/cite.202255284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- A. Perez Ortiz
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - D. Fröhlich
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - L. Gottheil
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - A. Penteado
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - E. Esche
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - J.-U. Repke
- Technische Universität Berlin Fachgebiet Dynamik und Betrieb technischer Anlagen Sekr. KWT 9, Str. des 17. Juni 135 10623 Berlin Germany
| | - R. Schomäcker
- Technische Universität Berlin Institut für Chemie Sekr. TC 8, Str. des 17. Juni 124 10623 Berlin Germany
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Weigand A, Bücs SL, Deleva S, Lukić Bilela L, Nyssen P, Paragamian K, Ssymank A, Weigand H, Zakšek V, Zagmajster M, Balázs G, Barjadze S, Bürger K, Burn W, Cailhol D, Decrolière A, Didonna F, Doli A, Drazina T, Dreybrodt J, Ðud L, Egri C, Erhard M, Finžgar S, Fröhlich D, Gartrell G, Gazaryan S, Georges M, Godeau JF, Grunewald R, Gunn J, Hajenga J, Hofmann P, Knight L, Köble H, Kuharic N, Lüthi C, Munteanu C, Novak R, Ozols D, Petkovic M, Stoch F, Vogel B, Vukovic I, Hall Weberg M, Zaenker C, Zaenker S, Feit U, Thies JC. Current cave monitoring practices, their variation and recommendations for future improvement in Europe: A synopsis from the 6th EuroSpeleo Protection Symposium. RIO 2022. [DOI: 10.3897/rio.8.e85859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This manuscript summarizes the outcomes of the 6th EuroSpeleo Protection Symposium. Special emphasis was laid on presenting and discussing monitoring activities under the umbrella of the Habitats Directive (EU Council Directive 92/43/EEC) for habitat type 8310 "Caves not open to the public" and the Emerald Network. The discussions revealed a high level of variation in the currently conducted underground monitoring activities: there is no uniform definition of what kind of underground environments the "cave" habitat should cover, how often a specific cave has to be monitored, and what parameters should be measured to evaluate the conservation status. The variation in spatial dimensions in national definitions of caves further affects the number of catalogued caves in a country and the number of caves to be monitored. Not always participants are aware of the complete national monitoring process and that data sets should be freely available or easily accessible. The discussions further showed an inherent dilemma between an anticipated uniform monitoring approach with a coherent assessment methodology and, on the contrary, the uniqueness of caves and subterranean biota to be assessed – combined with profound knowledge gaps and a lack of resources. Nevertheless, some good practices for future cave monitoring activities have been identified by the participants: (1) Cave monitoring should focus on bio- and geodiversity elements alike; (2) Local communities should be involved, and formal agreements envisaged; (3) Caves must be understood as windows into the subterranean realm; (4) Touristic caves should not be excluded ad-hoc from regular monitoring; (5) New digital tools and open FAIR data infrastructures should be implemented; (6) Cave biomonitoring should focus on a large(r) biological diversity; and (7) DNA-based tools should be integrated. Finally, the importance of the 'forgotten' Recommendation No. 36 from the Bern Convention as a guiding legal European document was highlighted.
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Klugmann M, Kalotay E, Delerue F, Ittner LM, Bongers A, Yu J, Morris MJ, Housley GD, Fröhlich D. Developmental delay and late onset HBSL pathology in hypomorphic Dars1 M256L mice. Neurochem Res 2022; 47:1972-1984. [PMID: 35357600 PMCID: PMC9217827 DOI: 10.1007/s11064-022-03582-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/05/2021] [Accepted: 03/15/2022] [Indexed: 12/03/2022]
Abstract
The leukodystrophy Hypomyelination with Brainstem and Spinal cord involvement and Leg spasticity (HBSL) is caused by recessive mutations of the DARS1 gene, which encodes the cytoplasmic aspartyl-tRNA synthetase. HBSL is a spectrum disorder with disease onset usually during early childhood and no available treatment options. Patients display regression of previously acquired motor milestones, spasticity, ataxia, seizures, nystagmus, and intellectual disabilities. Gene-function studies in mice revealed that homozygous Dars1 deletion is embryonically lethal, suggesting that successful modelling of HBSL requires the generation of disease-causing genocopies in mice. In this study, we introduced the pathogenic DARS1M256L mutation located on exon nine of the murine Dars1 locus. Despite causing severe illness in humans, homozygous Dars1M256L mice were only mildly affected. To exacerbate HBSL symptoms, we bred Dars1M256L mice with Dars1-null ‘enhancer’ mice. The Dars1M256L/− offspring displayed increased embryonic lethality, severe developmental delay, reduced body weight and size, hydrocephalus, anophthalmia, and vacuolization of the white matter. Remarkably, the Dars1M256L/− genotype affected energy metabolism and peripheral organs more profoundly than the nervous system and resulted in reduced body fat, increased respiratory exchange ratio, reduced liver steatosis, and reduced hypocellularity of the bone marrow. In summary, homozygous Dars1M256L and compound heterozygous Dars1M256L/− mutation genotypes recapitulate some aspects of HBSL and primarily manifest in developmental delay as well as metabolic and peripheral changes. These aspects of the disease might have been overlooked in HBSL patients with severe neurological deficits but could be included in the differential diagnosis of HBSL in the future.
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Affiliation(s)
- Matthias Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia.
| | - Elizabeth Kalotay
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Fabien Delerue
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2109, Sydney, NSW, Australia
| | - Lars M Ittner
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2109, Sydney, NSW, Australia
| | - Andre Bongers
- Biomedical Resources Imaging Laboratory, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Josephine Yu
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Margaret J Morris
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia.
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Fröhlich D, Gessler DJ, Klugmann M. Editorial: Myelin Repair: At the Crossing-Lines of Myelin Biology and Gene Therapy. Front Cell Neurosci 2022; 16:853742. [PMID: 35221929 PMCID: PMC8873078 DOI: 10.3389/fncel.2022.853742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Dominic J Gessler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, United States.,Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, United States.,Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States
| | - Matthias Klugmann
- Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
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KENFACK TSOBNANG P, Nchedoung Sakam YT, Fröhlich D, Porcher F, Rustam L, Hastürk E, Janiak C. Structural Transitions during the Water Sorption Process in two Layered Metal Hydrogen-Bonded Organic Frameworks and the Effect of the H-Bonds Strength between the Layers. CrystEngComm 2022. [DOI: 10.1039/d2ce00138a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The supramolecular network material [Co(amp)3][Cr(ox)3] (amp = 2-aminomethylpyridine, ox = oxalate) (I’) shows in its powder X-ray diffraction (PXRD) carpet plot during the water adsorption process two sets of diffraction...
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Kenfack PT, Nchedoung TYS, Fröhlich D, Hastürk E, Porcher F, Janiak C. Structural modifications occurring during the water sorption processes on a potential material for autonomous indoor humidity control. Acta Crystallogr A Found Adv 2021. [DOI: 10.1107/s0108767321095143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Muthiah A, Housley GD, Klugmann M, Fröhlich D. The Leukodystrophies HBSL and LBSL-Correlates and Distinctions. Front Cell Neurosci 2021; 14:626610. [PMID: 33574740 PMCID: PMC7870476 DOI: 10.3389/fncel.2020.626610] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Aminoacyl-tRNA synthetases (ARSs) accurately charge tRNAs with their respective amino acids. As such, they are vital for the initiation of cytosolic and mitochondrial protein translation. These enzymes have become increasingly scrutinized in recent years for their role in neurodegenerative disorders caused by the mutations of ARS-encoding genes. This review focuses on two such genes-DARS1 and DARS2-which encode cytosolic and mitochondrial aspartyl-tRNA synthetases, and the clinical conditions associated with mutations of these genes. We also describe attempts made at modeling these conditions in mice, which have both yielded important mechanistic insights. Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a disease caused by a range of mutations in the DARS2 gene, initially identified in 2003. Ten years later, hypomyelination with brainstem and spinal cord involvement and leg spasticity (HBSL), caused by mutations of cytosolic DARS1, was discovered. Multiple parallels have been drawn between the two conditions. The Magnetic Resonance Imaging (MRI) patterns are strikingly similar, but still set these two conditions apart from other leukodystrophies. Clinically, both conditions are characterized by lower limb spasticity, often associated with other pyramidal signs. However, perhaps due to earlier detection, a wider range of symptoms, including peripheral neuropathy, as well as visual and hearing changes have been described in LBSL patients. Both HBSL and LBSL are spectrum disorders lacking genotype to phenotype correlation. While the fatal phenotype of Dars1 or Dars2 single gene deletion mouse mutants revealed that the two enzymes lack functional redundancy, further pursuit of disease modeling are required to shed light onto the underlying disease mechanism, and enable examination of experimental treatments, including gene therapies.
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Affiliation(s)
| | | | | | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
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Fröhlich D, Mendes MI, Kueh AJ, Bongers A, Herold MJ, Salomons GS, Housley GD, Klugmann M. A Hypomorphic Dars1 D367Y Model Recapitulates Key Aspects of the Leukodystrophy HBSL. Front Cell Neurosci 2021; 14:625879. [PMID: 33551752 PMCID: PMC7855723 DOI: 10.3389/fncel.2020.625879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/21/2020] [Indexed: 01/18/2023] Open
Abstract
Hypomyelination with brain stem and spinal cord involvement and leg spasticity (HBSL) is a leukodystrophy caused by missense mutations of the aspartyl-tRNA synthetase-encoding gene DARS1. The clinical picture includes the regression of acquired motor milestones, spasticity, ataxia, seizures, nystagmus, and intellectual disabilities. Morphologically, HBSL is characterized by a distinct pattern of hypomyelination in the central nervous system including the anterior brainstem, the cerebellar peduncles and the supratentorial white matter as well as the dorsal columns and the lateral corticospinal tracts of the spinal cord. Adequate HBSL animal models are lacking. Dars1 knockout mice are embryonic lethal precluding examination of the etiology. To address this, we introduced the HBSL-causing Dars1 D367Y point mutation into the mouse genome. Surprisingly, mice carrying this mutation homozygously were phenotypically normal. As hypomorphic mutations are more severe in trans to a deletion, we crossed Dars1 D367Y/D367Y mice with Dars1-null carriers. The resulting Dars1 D367Y/- offspring displayed a strong developmental delay compared to control Dars1 D367Y/+ littermates, starting during embryogenesis. Only a small fraction of Dars1 D367Y/- mice were born, and half of these mice died with hydrocephalus during the first 3 weeks of life. Of the few Dars1 D367Y/- mice that were born at term, 25% displayed microphthalmia. Throughout postnatal life, Dars1 D367Y/- mice remained smaller and lighter than their Dars1 D367Y/+ littermates. Despite this early developmental deficit, once they made it through early adolescence Dars1 D367Y/- mice were phenotypically inconspicuous for most of their adult life, until they developed late onset motor deficits as well as vacuolization and demyelination of the spinal cord white matter. Expression levels of the major myelin proteins were reduced in Dars1 D367Y/- mice compared to controls. Taken together, Dars1 D367Y/- mice model aspects of the clinical picture of the corresponding missense mutation in HBSL. This model will enable studies of late onset deficits, which is precluded in Dars1 knockout mice, and can be leveraged to test potential HBSL therapeutics including DARS1 gene replacement therapy.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Marisa I. Mendes
- Metabolic Unit/Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Andrew J. Kueh
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Andre Bongers
- Biomedical Resources Imaging Laboratory, UNSW Sydney, Kensington, NSW, Australia
| | - Marco J. Herold
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Gajja S. Salomons
- Metabolic Unit/Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Gary D. Housley
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
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Frühbeis C, Kuo-Elsner WP, Müller C, Barth K, Peris L, Tenzer S, Möbius W, Werner HB, Nave KA, Fröhlich D, Krämer-Albers EM. Oligodendrocytes support axonal transport and maintenance via exosome secretion. PLoS Biol 2020; 18:e3000621. [PMID: 33351792 PMCID: PMC7787684 DOI: 10.1371/journal.pbio.3000621] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [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: 12/10/2019] [Revised: 01/06/2021] [Accepted: 12/10/2020] [Indexed: 12/28/2022] Open
Abstract
Neurons extend long axons that require maintenance and are susceptible to degeneration. Long-term integrity of axons depends on intrinsic mechanisms including axonal transport and extrinsic support from adjacent glial cells. The mechanisms of support provided by myelinating oligodendrocytes to underlying axons are only partly understood. Oligodendrocytes release extracellular vesicles (EVs) with properties of exosomes, which upon delivery to neurons improve neuronal viability in vitro. Here, we show that oligodendroglial exosome secretion is impaired in 2 mouse mutants exhibiting secondary axonal degeneration due to oligodendrocyte-specific gene defects. Wild-type oligodendroglial exosomes support neurons by improving the metabolic state and promoting axonal transport in nutrient-deprived neurons. Mutant oligodendrocytes release fewer exosomes, which share a common signature of underrepresented proteins. Notably, mutant exosomes lack the ability to support nutrient-deprived neurons and to promote axonal transport. Together, these findings indicate that glia-to-neuron exosome transfer promotes neuronal long-term maintenance by facilitating axonal transport, providing a novel mechanistic link between myelin diseases and secondary loss of axonal integrity. The long-term integrity of neuronal axons depends on intrinsic mechanisms such as axonal transport and on extrinsic support from adjacent glial cells. This study shows that genetic defects in glia that affect axonal integrity impair the secretion of oligodendrocyte exosomes and their ability to support nutrient-deprived neurons and promote axonal transport.
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Affiliation(s)
- Carsten Frühbeis
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Wen Ping Kuo-Elsner
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
- Focus Program Translational Neuroscience, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Christina Müller
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Kerstin Barth
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Leticia Peris
- Grenoble Institut des Neurosciences, Université Grenoble Alpes, Inserm, U1216, Grenoble, France
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Dominik Fröhlich
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
- Focus Program Translational Neuroscience, Johannes Gutenberg University of Mainz, Mainz, Germany
- * E-mail:
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13
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Das A, Fröhlich D, Achanta LB, Rowlands BD, Housley GD, Klugmann M, Rae CD. Correction to: L-Aspartate, L-Ornithine and L-Ornithine-L-Aspartate (LOLA) and Their Impact on Brain Energy Metabolism. Neurochem Res 2020; 45:2527. [PMID: 32638216 DOI: 10.1007/s11064-020-03087-y] [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: 10/23/2022]
Abstract
The original version of this published article, the bottom right hand panels of Figs. 3-6 were labelled as "Isotopomers formed from [1-13C]D-glucose". This is incorrect and should read "Isotopomers formed from [1,2-13C]acetate". This has been corrected by publishing this correction article.
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Affiliation(s)
- Abhijit Das
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,School of Medical Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Lavanya B Achanta
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Benjamin D Rowlands
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia. .,School of Medical Sciences, The University of New South Wales, Sydney, NSW, Australia.
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14
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Das A, Fröhlich D, Achanta LB, Rowlands BD, Housley GD, Klugmann M, Rae CD. L-Aspartate, L-Ornithine and L-Ornithine-L-Aspartate (LOLA) and Their Impact on Brain Energy Metabolism. Neurochem Res 2020; 45:1438-1450. [PMID: 32424601 DOI: 10.1007/s11064-020-03044-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/25/2020] [Accepted: 04/29/2020] [Indexed: 12/11/2022]
Abstract
L-Ornithine-L-aspartate (LOLA), a crystalline salt, is used primarily in the management of hepatic encephalopathy. The degree to which it might penetrate the brain, and the effects it might have on metabolism in brain are poorly understood. Here, to investigate the effects of LOLA on brain energy metabolism we incubated brain cortical tissue slices from guinea pig (Cavea porcellus) with the constituent amino acids of LOLA, L-ornithine or L-aspartate, as well as LOLA, in the presence of [1-13C]D-glucose and [1,2-13C]acetate; these labelled substrates are useful indicators of brain metabolic activity. L-Ornithine produced significant "sedative" effects on brain slice metabolism, most likely via conversion of ornithine to GABA via the ornithine aminotransferase pathway, while L-aspartate showed concentration-dependent excitatory effects. The metabolic effects of LOLA reflected a mix of these two different processes and were concentration-dependent. We also investigated the effect of an intraperitoneal bolus injection of L-ornithine, L-aspartate or LOLA on levels of metabolites in kidney, liver and brain cortex and brain stem in mice (C57Bl6J) 1 h later. No significant changes in metabolite levels were seen following the bolus injection of L-aspartate, most likely due to rapid metabolism of aspartate before reaching the target tissue. Brain cortex glutamate was decreased by L-ornithine but no other brain effects were observed with any other compound. Kidney levels of aspartate were increased after injection of L-ornithine and LOLA which may be due to interference by ornithine with the kidney urea cycle. It is likely that without optimising chronic intravenous infusion, LOLA has minimal impact on healthy brain energy metabolism due to systemic clearance and the blood - brain barrier.
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Affiliation(s)
- Abhijit Das
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,School of Medical Sciences, The University of New South Wales, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Lavanya B Achanta
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Benjamin D Rowlands
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia.,Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility, School of Medical Sciences, The University of New South Wales, Kensington, 2052, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Barker St, Randwick, NSW, 2031, Australia. .,School of Medical Sciences, The University of New South Wales, Sydney, NSW, Australia.
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15
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Lenzen D, Eggebrecht JG, Mileo PGM, Fröhlich D, Henninger S, Atzori C, Bonino F, Lieb A, Maurin G, Stock N. Unravelling the water adsorption in a robust iron carboxylate metal–organic framework. Chem Commun (Camb) 2020; 56:9628-9631. [DOI: 10.1039/d0cc03489d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Scale-up of an Fe-MOF and elucidation of its water adsorption properties by PXRD, sorption measurements and molecular simulations are reported.
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Affiliation(s)
- Dirk Lenzen
- Institute of Inorganic Chemistry
- Christian-Albrechts-Universität Kiel
- 24118 Kiel
- Germany
| | - Jakob G. Eggebrecht
- Otto-von-Guericke-Universität Magdeburg
- Institut für Chemie
- 39106 Magdeburg
- Germany
| | | | - Dominik Fröhlich
- Department Heating and Cooling Technologies
- Group Sorption Materials
- Fraunhofer-Institut für Solare Energiesysteme ISE
- 79110 Freiburg
- Germany
| | - Stefan Henninger
- Department Heating and Cooling Technologies
- Group Sorption Materials
- Fraunhofer-Institut für Solare Energiesysteme ISE
- 79110 Freiburg
- Germany
| | - Cesare Atzori
- Department of Chemistry
- NIS and INSTM Reference Centre
- Università di Torino
- I-10125 Torino
- Italy
| | - Francesca Bonino
- Department of Chemistry
- NIS and INSTM Reference Centre
- Università di Torino
- I-10125 Torino
- Italy
| | - Alexandra Lieb
- Otto-von-Guericke-Universität Magdeburg
- Institut für Chemie
- 39106 Magdeburg
- Germany
| | | | - Norbert Stock
- Institute of Inorganic Chemistry
- Christian-Albrechts-Universität Kiel
- 24118 Kiel
- Germany
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16
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Auber M, Fröhlich D, Drechsel O, Karaulanov E, Krämer-Albers EM. Serum-free media supplements carry miRNAs that co-purify with extracellular vesicles. J Extracell Vesicles 2019; 8:1656042. [PMID: 31552133 PMCID: PMC6746277 DOI: 10.1080/20013078.2019.1656042] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/08/2019] [Accepted: 08/07/2019] [Indexed: 12/29/2022] Open
Abstract
Recent studies on extracellular RNA raised awareness that extracellular vesicles (EVs) isolated from cultured cells may co-purify RNAs derived from media supplements such as fetal bovine serum (FBS) confounding EV-associated RNA. Defined culture media supplemented with a range of nutrient components provide an alternative to FBS addition and allow EV-collection under full medium conditions avoiding starvation and cell stress during the collection period. However, the potential contribution of serum-free media supplements to EV-RNA contamination has remained elusive and has never been assessed. Here, we report that RNA isolated from EVs harvested from cells under serum-replacement conditions includes miRNA contaminants carried into the sample by defined media components. Subjecting unconditioned, EV-free medium to differential centrifugation followed by reverse transcription quantitative PCR (RT-qPCR) on RNA isolated from the pellet resulted in detection of miRNAs that had been classified as EV-enriched by RNA-seq or RT-qPCR of an isolated EV-fraction. Ribonuclease (RNase-A) and detergent treatment removed most but not all of the contaminating miRNAs. Further analysis of the defined media constituents identified Catalase as a main source of miRNAs co-isolating together with EVs. Hence, miRNA contaminants can be carried into EV-samples even under serum-free harvesting conditions using culture media that are expected to be chemically defined. Formulation of miRNA-free media supplements may provide a solution to collect EVs clean from confounding miRNAs, which however still remains a challenging task. Differential analysis of EVs collected under full medium and supplement-deprived conditions appears to provide a strategy to discriminate confounding and EV-associated RNA. In conclusion, we recommend careful re-evaluation and validation of EV small RNA-seq and RT-qPCR datasets by determining potential medium background.
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Affiliation(s)
- Martin Auber
- Institute of Developmental Biology and Neurobiology, Biology of Extracellular Vesicles, University of Mainz, Mainz, Germany
| | - Dominik Fröhlich
- Institute of Developmental Biology and Neurobiology, Biology of Extracellular Vesicles, University of Mainz, Mainz, Germany
| | - Oliver Drechsel
- Bioinformatics Core Facility, Institute of Molecular Biology, Mainz, Germany
| | - Emil Karaulanov
- Bioinformatics Core Facility, Institute of Molecular Biology, Mainz, Germany
| | - Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Biology of Extracellular Vesicles, University of Mainz, Mainz, Germany
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17
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Lenzen D, Zhao J, Ernst SJ, Wahiduzzaman M, Ken Inge A, Fröhlich D, Xu H, Bart HJ, Janiak C, Henninger S, Maurin G, Zou X, Stock N. A metal-organic framework for efficient water-based ultra-low-temperature-driven cooling. Nat Commun 2019; 10:3025. [PMID: 31289274 PMCID: PMC6616384 DOI: 10.1038/s41467-019-10960-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/07/2019] [Indexed: 11/09/2022] Open
Abstract
Efficient use of energy for cooling applications is a very important and challenging field in science. Ultra-low temperature actuated (Tdriving < 80 °C) adsorption-driven chillers (ADCs) with water as the cooling agent are one environmentally benign option. The nanoscale metal-organic framework [Al(OH)(C6H2O4S)] denoted CAU-23 was discovered that possess favorable properties, including water adsorption capacity of 0.37 gH2O/gsorbent around p/p0 = 0.3 and cycling stability of at least 5000 cycles. Most importantly the material has a driving temperature down to 60 °C, which allows for the exploitation of yet mostly unused temperature sources and a more efficient use of energy. These exceptional properties are due to its unique crystal structure, which was unequivocally elucidated by single crystal electron diffraction. Monte Carlo simulations were performed to reveal the water adsorption mechanism at the atomic level. With its green synthesis, CAU-23 is an ideal material to realize ultra-low temperature driven ADC devices.
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Affiliation(s)
- Dirk Lenzen
- Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Str. 2, 24118, Kiel, Germany
| | - Jingjing Zhao
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Sebastian-Johannes Ernst
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany.,TU Kaiserslautern, Chair of Separation Science and Technology, P.O. Box 3049, 67653, Kaiserslautern, Germany
| | - Mohammad Wahiduzzaman
- Institut Charles Gerhardt Montpellier, Université Montpellier, UMR 5253 CNRS ENSCM UM, 34095 Montpellier, France
| | - A Ken Inge
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Dominik Fröhlich
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Hongyi Xu
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Hans-Jörg Bart
- TU Kaiserslautern, Chair of Separation Science and Technology, P.O. Box 3049, 67653, Kaiserslautern, Germany
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie I, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Stefan Henninger
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany.
| | - Guillaume Maurin
- Institut Charles Gerhardt Montpellier, Université Montpellier, UMR 5253 CNRS ENSCM UM, 34095 Montpellier, France.
| | - Xiaodong Zou
- Department of Materials and Environmental Chemistry, Stockholm University, SE-106 91, Stockholm, Sweden.
| | - Norbert Stock
- Institut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth-Str. 2, 24118, Kiel, Germany.
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18
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Abstract
The water sorption behaviour of aluminium MOF CAU-10 and CAU-15-Cit was followed by in situ powder X-ray diffraction.
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Affiliation(s)
- Dominik Fröhlich
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - Philipp Hügenell
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - Helge Reinsch
- Institute of Inorganic Chemistry
- Christian-Albrechts-University Kiel
- D-24118 Kiel
- Germany
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19
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Heckötter J, Freitag M, Fröhlich D, Aßmann M, Bayer M, Grünwald P, Schöne F, Semkat D, Stolz H, Scheel S. Rydberg Excitons in the Presence of an Ultralow-Density Electron-Hole Plasma. Phys Rev Lett 2018; 121:097401. [PMID: 30230865 DOI: 10.1103/physrevlett.121.097401] [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] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/14/2017] [Indexed: 06/08/2023]
Abstract
We study the Rydberg exciton absorption of Cu_{2}O in the presence of free carriers injected by above-band-gap illumination. Already at plasma densities ρ_{EH} below one hundredth electron-hole pair per μm^{3}, exciton lines are bleached, starting from the highest observed principal quantum number, while their energies remain constant. Simultaneously, the band gap decreases by correlation effects with the plasma. An exciton line loses oscillator strength when the band gap approaches its energy, vanishing completely at the crossing point. Adapting a plasma-physics description, we describe the observations by an effective Bohr radius that increases with rising plasma density, reflecting the Coulomb interaction screening by the plasma.
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Affiliation(s)
- J Heckötter
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Freitag
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - D Fröhlich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - P Grünwald
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - F Schöne
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - D Semkat
- Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, Felix-Hausdorff-Straße 6, D-17489 Greifswald, Germany
| | - H Stolz
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
| | - S Scheel
- Institut für Physik, Universität Rostock, Albert-Einstein-Straße 23-24, D-18059 Rostock, Germany
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20
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Splith T, Fröhlich D, Henninger SK, Stallmach F. Development and application of an exchange model for anisotropic water diffusion in the microporous MOF aluminum fumarate. J Magn Reson 2018; 291:40-46. [PMID: 29698909 DOI: 10.1016/j.jmr.2018.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/13/2018] [Accepted: 04/13/2018] [Indexed: 06/08/2023]
Abstract
Diffusion of water in aluminum fumarate was studied by means of pulsed field gradient (PFG) nuclear magnetic resonance (NMR). Due to water molecules exchanging between the intracrystalline anisotropic pore space and the isotropic intercrystalline void space the model of intracrystalline anisotropic diffusion fails to describe the experimental PFG NMR data at high observation times. Therefore, the two-site exchange model developed by Kärger is extended to the case of exchange between an anisotropic and an isotropic site. This extended exchange model is solved by numerical integration. It describes the experimental data very well and yields values for the intracrystalline diffusion coefficient and the mean residence times of the respective sites. Further PFG NMR studies were performed with coatings consisting of small aluminum fumarate crystals, which are used in adsorptive heat transformation applications. The diffusion coefficients of water in the small crystal coating are compared to the values expected from the extended two-site exchange model and from the model of long-range diffusion.
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Affiliation(s)
- Tobias Splith
- University of Leipzig, Faculty of Physics and Earth Sciences, Linnéstr. 5, 04103 Leipzig, Germany
| | - Dominik Fröhlich
- Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg, Germany
| | - Stefan K Henninger
- Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg, Germany
| | - Frank Stallmach
- University of Leipzig, Faculty of Physics and Earth Sciences, Linnéstr. 5, 04103 Leipzig, Germany.
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21
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Fröhlich D, Suchowerska AK, Voss C, He R, Wolvetang E, von Jonquieres G, Simons C, Fath T, Housley GD, Klugmann M. Expression Pattern of the Aspartyl-tRNA Synthetase DARS in the Human Brain. Front Mol Neurosci 2018; 11:81. [PMID: 29615866 PMCID: PMC5869200 DOI: 10.3389/fnmol.2018.00081] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/01/2018] [Indexed: 12/21/2022] Open
Abstract
Translation of mRNA into protein is an evolutionarily conserved, fundamental process of life. A prerequisite for translation is the accurate charging of tRNAs with their cognate amino acids, a reaction catalyzed by specific aminoacyl-tRNA synthetases. One of these enzymes is the aspartyl-tRNA synthetase DARS, which pairs aspartate with its corresponding tRNA. Missense mutations of the gene encoding DARS result in the leukodystrophy hypomyelination with brainstem and spinal cord involvement and leg spasticity (HBSL) with a distinct pattern of hypomyelination, motor abnormalities, and cognitive impairment. A thorough understanding of the DARS expression domains in the central nervous system is essential for the development of targeted therapies to treat HBSL. Here, we analyzed endogenous DARS expression on the mRNA and protein level in different brain regions and cell types of human post mortem brain tissue as well as in human stem cell derived neurons, oligodendrocytes, and astrocytes. DARS expression is significantly enriched in the cerebellum, a region affected in HBSL patients and important for motor control. Although obligatorily expressed in all cells, DARS shows a distinct expression pattern with enrichment in neurons but only low abundance in oligodendrocytes, astrocytes, and microglia. Our results reveal little homogeneity across the different cell types, largely matching previously published data in the murine brain. This human gene expression study will significantly contribute to the understanding of DARS gene function and HBSL pathology and will be instrumental for future development of animal models and targeted therapies. In particular, we anticipate high benefit from a gene replacement approach in neurons of HBSL mouse models, given the abundant endogenous DARS expression in this lineage cell.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Alexandra K Suchowerska
- Neurodegenerative and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Carola Voss
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Ruojie He
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia.,Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ernst Wolvetang
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Cas Simons
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Thomas Fath
- Neurodegenerative and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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22
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Lenzen D, Bendix P, Reinsch H, Fröhlich D, Kummer H, Möllers M, Hügenell PPC, Gläser R, Henninger S, Stock N. Scalable Green Synthesis and Full-Scale Test of the Metal-Organic Framework CAU-10-H for Use in Adsorption-Driven Chillers. Adv Mater 2018; 30:1705869. [PMID: 29271497 DOI: 10.1002/adma.201705869] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 11/03/2017] [Indexed: 05/24/2023]
Abstract
The demand for cooling devices has increased during the last years and this trend will continue. Adsorption-driven chillers (ADCs) using water as the working fluid and low temperature waste energy for regeneration are an environmentally friendly alternative to currently employed cooling devices and can concurrently help to dramatically decrease energy consumption. Due to the ideal water sorption behavior and proven lifetime stability of [Al(OH)(m-BDC)] ∙ x H2 O (m-BDC2- = 1,3-benzenedicarboxylate), also denoted CAU-10-H, a green very robust synthesis process under reflux, with high yields up to 95% is developed and scaled up to 12 kg-scale. Shaping of the adsorbent is demonstrated, which is important for an application. Thus monoliths and coatings of CAU-10-H are produced using a water-based binder. The composites are thoroughly characterized toward their mechanical stability and water sorption behavior. Finally a full-scale heat exchanger is coated and tested under ADC working conditions. Fast adsorption dynamic leads to a high power output and a good power density. A low regeneration temperature of only 70 °C is demonstrated, allowing the use of low temperature sources like waste heat and solar thermal collectors.
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Affiliation(s)
- Dirk Lenzen
- Christian-Albrechts-Universität Kiel, Institut für Anorganische Chemie, Max-Eyth-Str. 2, 24118, Kiel, Germany
| | - Phillip Bendix
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Helge Reinsch
- Christian-Albrechts-Universität Kiel, Institut für Anorganische Chemie, Max-Eyth-Str. 2, 24118, Kiel, Germany
| | - Dominik Fröhlich
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Harry Kummer
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Marc Möllers
- Department Heating and Cooling Technologies, Group Equipment and Component Development, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Philipp P C Hügenell
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Roger Gläser
- Institut für Technische Chemie, Universität Leipzig, Linnéstraße 3, 04103, Leipzig, Germany
| | - Stefan Henninger
- Department Heating and Cooling Technologies, Group Sorption Materials, Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstrasse 2, 79110, Freiburg, Germany
| | - Norbert Stock
- Christian-Albrechts-Universität Kiel, Institut für Anorganische Chemie, Max-Eyth-Str. 2, 24118, Kiel, Germany
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23
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Reinsch H, Homburg T, Heidenreich N, Fröhlich D, Hennninger S, Wark M, Stock N. Green Synthesis of a New Al-MOF Based on the Aliphatic Linker Mesaconic Acid: Structure, Properties and In Situ Crystallisation Studies of Al-MIL-68-Mes. Chemistry 2018; 24:2173-2181. [DOI: 10.1002/chem.201704771] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Helge Reinsch
- Institut für Anorganische Chemie der; CAU Kiel; Max-Eyth-Straße 2 24118 Kiel Germany
- MOF Apps AS; c/o Smidig Regnskapsservice ANS, P. Box 24 Tåsen; 0801 Oslo Norway
| | - Thomas Homburg
- Institut für Anorganische Chemie der; CAU Kiel; Max-Eyth-Straße 2 24118 Kiel Germany
| | - Niclas Heidenreich
- Institut für Anorganische Chemie der; CAU Kiel; Max-Eyth-Straße 2 24118 Kiel Germany
| | - Dominik Fröhlich
- Fraunhofer Institute for Solar Energy Systems ISE; Heidenhofstrasse 2 79110 Freiburg Germany
| | - Stefan Hennninger
- Fraunhofer Institute for Solar Energy Systems ISE; Heidenhofstrasse 2 79110 Freiburg Germany
| | - Michael Wark
- Institut für Chemie; Carl von Ossietzky Universität Oldenburg; Carl-von-Ossietzky-Strasse 9-11 26129 Oldenburg Germany
| | - Norbert Stock
- Institut für Anorganische Chemie der; CAU Kiel; Max-Eyth-Straße 2 24118 Kiel Germany
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Hochstrasser L, Fröhlich D, Schneeberger AR, Borgwardt S, Lang UE, Stieglitz RD, Huber CG. Long-term reduction of seclusion and forced medication on a hospital-wide level: Implementation of an open-door policy over 6 years. Eur Psychiatry 2018; 48:51-57. [PMID: 29331599 DOI: 10.1016/j.eurpsy.2017.09.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/01/2017] [Accepted: 09/13/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Psychiatric inpatient treatment is increasingly performed in settings with locked doors. However, locked wards have well-known disadvantages and are ethically problematic. In addition, recent data challenges the hypothesis that locked wards provide improved safety over open-door settings regarding suicide, absconding and aggression. Furthermore, there is evidence that the introduction of an open-door policy may lead to short-term reductions in involuntary measures. The aim of this study was to assess if the introduction of an open-door policy is associated with a long-term reduction of the frequency of seclusion and forced medication. METHOD In this 6-year, hospital-wide, longitudinal, observational study, we examined the frequency of seclusion and forced medication in 17,359 inpatient cases admitted to the Department of Adult Psychiatry, Universitäre Psychiatrische Kliniken (UPK) Basel, University of Basel, Switzerland. In an approach to enable a less restrictive policy, six previously closed psychiatric wards were permanently opened beginning from August 2011. During this process, a systematic change towards a more patient-centered and recovery-oriented care was applied. Statistical analysis consisted of generalized estimating equations (GEE) models. RESULTS In multivariate analyses controlling for potential confounders, the implementation of an open-door policy was associated with a continuous reduction of seclusion (from 8.2 to 3.5%; ηp2=0.82; odds ratio: 0.88) and forced medication (from 2.4 to 1.2%; ηp2=0.70; odds ratio: 0.90). CONCLUSION This underlines the potential of the introduction of an open-door policy to attain a long-term reduction in involuntary measures.
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Affiliation(s)
- L Hochstrasser
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland.
| | - D Fröhlich
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland
| | - A R Schneeberger
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland; Psychiatrische Dienste Graubünden, 220, Loëstrasse, 7000 Chur, Switzerland; Albert Einstein College of Medicine, Department of Psychiatry and Behavioral Sciences, 3331, Bainbridge Avenue, Bronx, New York, NY 10467, USA
| | - S Borgwardt
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland
| | - U E Lang
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland
| | - R-D Stieglitz
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland; Universität Basel, Fakultät für Psychologie, Abteilung für Klinische Psychologie und Psychiatrie, 60/62, Missionsstrasse, 4055 Basel, Switzerland
| | - C G Huber
- Universitäre Psychiatrische Kliniken Basel, Universität Basel, 27, Wilhelm Klein-Strasse, 4012 Basel, Switzerland
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25
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Waitschat S, Fröhlich D, Reinsch H, Terraschke H, Lomachenko KA, Lamberti C, Kummer H, Helling T, Baumgartner M, Henninger S, Stock N. Synthesis of M-UiO-66 (M = Zr, Ce or Hf) employing 2,5-pyridinedicarboxylic acid as a linker: defect chemistry, framework hydrophilisation and sorption properties. Dalton Trans 2018; 47:1062-1070. [DOI: 10.1039/c7dt03641h] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
MOFs of general composition [M6(OH)4(O)4(PDC)6−x(Cl)2x(H2O)2x] with M = Zr, Ce, Hf; and 0 ≤ x ≤ 2 were obtained and characterised in detail.
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Affiliation(s)
- S. Waitschat
- Institut für Anorganische Chemie
- Christian-Albrechts-Universität
- D 24118 Kiel
- Germany
| | - D. Fröhlich
- Fraunhofer-Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - H. Reinsch
- Institut für Anorganische Chemie
- Christian-Albrechts-Universität
- D 24118 Kiel
- Germany
| | - H. Terraschke
- Institut für Anorganische Chemie
- Christian-Albrechts-Universität
- D 24118 Kiel
- Germany
| | - K. A. Lomachenko
- European Synchrotron Radiation Facility
- 38043 Grenoble Cedex 9
- France
- IRC “Smart Materials”
- Southern Federal University
| | - C. Lamberti
- IRC “Smart Materials”
- Southern Federal University
- 344090 Rostov-on-Don
- Russia
- Department of Chemistry
| | - H. Kummer
- Fraunhofer-Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - T. Helling
- Fraunhofer-Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - M. Baumgartner
- Fraunhofer-Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - S. Henninger
- Fraunhofer-Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - N. Stock
- Institut für Anorganische Chemie
- Christian-Albrechts-Universität
- D 24118 Kiel
- Germany
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26
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Reinsch H, Fröhlich D, Waitschat S, Chavan S, Lillerud KP, Henninger S, Stock N. Optimisation of synthesis conditions for UiO-66-CO2H towards scale-up and its vapour sorption properties. REACT CHEM ENG 2018. [DOI: 10.1039/c7re00214a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The zirconium MOF UiO-66-CO2H was obtained under green synthesis conditions and thoroughly characterised, focussing on its vapour sorption properties.
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Affiliation(s)
- Helge Reinsch
- Institute of Inorganic Chemistry
- 24118 Kiel
- Germany
- MOF Apps AS
- 0801 Oslo
| | - Dominik Fröhlich
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | | | - Sachin Chavan
- Department of Chemistry
- University of Oslo
- 0315 Oslo
- Norway
- ProfMOF AS
| | | | - Stefan Henninger
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg
- Germany
| | - Norbert Stock
- Institute of Inorganic Chemistry
- 24118 Kiel
- Germany
- Department of Chemistry
- University of Oslo
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27
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Ernst SJ, Baumgartner M, Fröhlich D, Bart HJ, Henninger SK. Adsorbentien für sorptionsgestützte Klimatisierung, Entfeuchtung und Wassergewinnung. CHEM-ING-TECH 2017. [DOI: 10.1002/cite.201700038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sebastian-Johannes Ernst
- Fraunhofer-Institut für Solare Energiesysteme; Abteilung Wärme- und Kältetechnik; Heidenhofstraße 2 79110 Freiburg Deutschland
- TU Kaiserslautern; Lehrstuhl für Thermische Verfahrenstechnik; Postfach 3049 67653 Kaiserslautern Deutschland
| | - Max Baumgartner
- Fraunhofer-Institut für Solare Energiesysteme; Abteilung Wärme- und Kältetechnik; Heidenhofstraße 2 79110 Freiburg Deutschland
| | - Dominik Fröhlich
- Fraunhofer-Institut für Solare Energiesysteme; Abteilung Wärme- und Kältetechnik; Heidenhofstraße 2 79110 Freiburg Deutschland
| | - Hans-Jörg Bart
- TU Kaiserslautern; Lehrstuhl für Thermische Verfahrenstechnik; Postfach 3049 67653 Kaiserslautern Deutschland
| | - Stefan Kai Henninger
- Fraunhofer-Institut für Solare Energiesysteme; Abteilung Wärme- und Kältetechnik; Heidenhofstraße 2 79110 Freiburg Deutschland
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28
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Kummer H, Jeremias F, Warlo A, Füldner G, Fröhlich D, Janiak C, Gläser R, Henninger SK. A Functional Full-Scale Heat Exchanger Coated with Aluminum Fumarate Metal–Organic Framework for Adsorption Heat Transformation. Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.7b00106] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Harry Kummer
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
- Institut
für Technische Chemie, Universität Leipzig, Linnéstraße
3, 04103 Leipzig, Germany
| | - Felix Jeremias
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
| | - Alexander Warlo
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
| | - Gerrit Füldner
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
| | - Dominik Fröhlich
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
- Institut
für Anorganische Chemie und Strukturchemie, Universität Düsseldorf, 40204 Düsseldorf, Germany
| | - Christoph Janiak
- Institut
für Anorganische Chemie und Strukturchemie, Universität Düsseldorf, 40204 Düsseldorf, Germany
| | - Roger Gläser
- Institut
für Technische Chemie, Universität Leipzig, Linnéstraße
3, 04103 Leipzig, Germany
| | - Stefan K. Henninger
- Division
Thermal Systems and Buildings, Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg, Germany
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29
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Ketterer C, Gangwisch M, Fröhlich D, Matzarakis A. Comparison of selected approaches for urban roughness determination based on voronoi cells. Int J Biometeorol 2017; 61:189-198. [PMID: 27369974 DOI: 10.1007/s00484-016-1203-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/14/2016] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
Wind speed is reduced above urban areas due to their high aerodynamic roughness. This not only holds for above the urban canopy. The local vertical wind profile is modified. Aerodynamic roughness (both roughness length and displacement height) therefore is relevant for many fields within human biometeorology, e.g. for the identification of ventilation paths, the concentration and dispersion of air pollutants at street level or to simulate wind speed and direction in urban environments and everything depending on them. Roughness, thus, also shows strong influence on human thermal comfort. Currently, roughness parameters are mostly estimated using classifications. However, such classifications only provide limited assessment of roughness in urban areas. In order to calculate spatially resolved roughness on the micro-scale, three different approaches were implemented in the SkyHelios model. For all of them, the urban area is divided into reference areas for each of the obstacles using a voronoi diagram. The three approaches are based on building and [+one of them also on] vegetation (trees and forests) data. They were compared for the city of Stuttgart, Germany. Results show that the approach after Bottema and Mestayer (J Wind Eng Ind Aerodyn 74-76:163-173 1998) on the spatial basis of a voronoi diagram provides the most plausible results.
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Affiliation(s)
- Christine Ketterer
- iMA Richter & Röckle, Eisenbahnstrasse 43, 79098, Freiburg, Germany
- Chair of Environmental Meteorology, Albert-Ludwigs- University of Freiburg, Werthmannstraße 10, 79085, Freiburg, Germany
| | - Marcel Gangwisch
- Chair of Environmental Meteorology, Albert-Ludwigs- University of Freiburg, Werthmannstraße 10, 79085, Freiburg, Germany
| | - Dominik Fröhlich
- Chair of Environmental Meteorology, Albert-Ludwigs- University of Freiburg, Werthmannstraße 10, 79085, Freiburg, Germany.
| | - Andreas Matzarakis
- Research Center Human Biometeorology, Deutscher Wetterdienst, Stefan-Meier-Str. 4, 79104, Freiburg, Germany
- Faculty of Environment and Natural Resources, Albert-Ludwigs-University Freiburg, 79085, Freiburg, Germany
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30
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Grünwald P, Aßmann M, Heckötter J, Fröhlich D, Bayer M, Stolz H, Scheel S. Signatures of Quantum Coherences in Rydberg Excitons. Phys Rev Lett 2016; 117:133003. [PMID: 27715094 DOI: 10.1103/physrevlett.117.133003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Indexed: 06/06/2023]
Abstract
Coherent optical control of individual particles has been demonstrated both for atoms and semiconductor quantum dots. Here we demonstrate the emergence of quantum coherent effects in semiconductor Rydberg excitons in bulk Cu_{2}O. Because of the spectral proximity between two adjacent Rydberg exciton states, a single-frequency laser may pump both resonances with little dissipation from the detuning. As a consequence, additional resonances appear in the absorption spectrum that correspond to dressed states consisting of two Rydberg exciton levels coupled to the excitonic vacuum, forming a V-type three-level system, but driven only by one laser light source. We show that the level of pure dephasing in this system is extremely low. These observations are a crucial step towards coherently controlled quantum technologies in a bulk semiconductor.
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Affiliation(s)
- P Grünwald
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
| | - M Aßmann
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - J Heckötter
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - D Fröhlich
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - M Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - H Stolz
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
| | - S Scheel
- Institut für Physik, Universität Rostock, Albert-Einstein-Strasse 23, D-18059 Rostock, Germany
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31
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von Jonquieres G, Fröhlich D, Klugmann CB, Wen X, Harasta AE, Ramkumar R, Spencer ZHT, Housley GD, Klugmann M. Recombinant Human Myelin-Associated Glycoprotein Promoter Drives Selective AAV-Mediated Transgene Expression in Oligodendrocytes. Front Mol Neurosci 2016; 9:13. [PMID: 26941604 PMCID: PMC4763065 DOI: 10.3389/fnmol.2016.00013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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: 12/23/2015] [Accepted: 02/05/2016] [Indexed: 11/13/2022] Open
Abstract
Leukodystrophies are hereditary central white matter disorders caused by oligodendrocyte dysfunction. Recent clinical trials for some of these devastating neurological conditions have employed an ex vivo gene therapy approach that showed improved endpoints because cross-correction of affected myelin-forming cells occurred following secretion of therapeutic proteins by transduced autologous grafts. However, direct gene transfer to oligodendrocytes is required for the majority of leukodystrophies with underlying mutations in genes encoding non-secreted oligodendroglial proteins. Recombinant adeno-associated viral (AAV) vectors are versatile tools for gene transfer to the central nervous system (CNS) and proof-of-concept studies in rodents have shown that the use of cellular promoters is sufficient to target AAV-mediated transgene expression to glia. The potential of this strategy has not been exploited. The major caveat of the AAV system is its limited packaging capacity of ~5 kb, providing the rationale for identifying small yet selective recombinant promoters. Here, we characterize the human myelin associated glycoprotein (MAG) promoter for reliable targeting of AAV-mediated transgene expression to oligodendrocytes in vivo. A homology screen revealed highly conserved genomic regions among mammalian species upstream of the transcription start site. Recombinant AAV expression cassettes carrying the cDNA encoding enhanced green fluorescent protein (GFP) driven by truncated versions of the recombinant MAG promoter (2.2, 1.5 and 0.3 kb in size) were packaged as cy5 vectors and delivered into the dorsal striatum of mice. At 3 weeks post-injection, oligodendrocytes, neurons and astrocytes expressing the reporter were quantified by immunohistochemical staining. Our results revealed that both 2.2 and 1.5 kb MAG promoters targeted more than 95% of transgene expression to oligodendrocytes. Even the short 0.3 kb fragment conveyed high oligodendroglial specific transgene expression (>90%) in vivo. Moreover, cy5-MAG2.2-GFP delivery to the neonate CNS resulted in selective GFP expression in oligodendrocytes for at least 8 months. Broadly, the characterization of the extremely short yet oligodendrocyte-specific human MAG promoter may facilitate modeling neurological diseases caused by oligodendrocyte pathology and has translational relevance for leukodystrophy gene therapy.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Claudia B Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Xin Wen
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Anne E Harasta
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Roshini Ramkumar
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Ziggy H T Spencer
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
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32
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Fröhlich D, Kuo WP, Frühbeis C, Sun JJ, Zehendner CM, Luhmann HJ, Pinto S, Toedling J, Trotter J, Krämer-Albers EM. Multifaceted effects of oligodendroglial exosomes on neurons: impact on neuronal firing rate, signal transduction and gene regulation. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0510. [PMID: 25135971 DOI: 10.1098/rstb.2013.0510] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Exosomes are small membranous vesicles of endocytic origin that are released by almost every cell type. They exert versatile functions in intercellular communication important for many physiological and pathological processes. Recently, exosomes attracted interest with regard to their role in cell-cell communication in the nervous system. We have shown that exosomes released from oligodendrocytes upon stimulation with the neurotransmitter glutamate are internalized by neurons and enhance the neuronal stress tolerance. Here, we demonstrate that oligodendroglial exosomes also promote neuronal survival during oxygen-glucose deprivation, a model of cerebral ischaemia. We show the transfer from oligodendrocytes to neurons of superoxide dismutase and catalase, enzymes which are known to help cells to resist oxidative stress. Additionally, we identify various effects of oligodendroglial exosomes on neuronal physiology. Electrophysiological analysis using in vitro multi-electrode arrays revealed an increased firing rate of neurons exposed to oligodendroglial exosomes. Moreover, gene expression analysis and phosphorylation arrays uncovered differentially expressed genes and altered signal transduction pathways in neurons after exosome treatment. Our study thus provides new insight into the broad spectrum of action of oligodendroglial exosomes and their effects on neuronal physiology. The exchange of extracellular vesicles between neural cells may exhibit remarkable potential to impact brain performance.
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Affiliation(s)
- Dominik Fröhlich
- Molecular Cell Biology, University of Mainz, 55128 Mainz, Germany
| | - Wen Ping Kuo
- Molecular Cell Biology, University of Mainz, 55128 Mainz, Germany Focus Programme Translational Neuroscience, University of Mainz, 55128 Mainz, Germany
| | - Carsten Frühbeis
- Molecular Cell Biology, University of Mainz, 55128 Mainz, Germany
| | - Jyh-Jang Sun
- Institute of Physiology, University Medical Center, 55128 Mainz, Germany Neuro-Electronics Research Flanders, 3001 Leuven, Belgium
| | - Christoph M Zehendner
- Institute of Physiology, University Medical Center, 55128 Mainz, Germany ZIM III, Department of Cardiology, Goethe University Frankfurt, 60389 Frankfurt, Germany
| | - Heiko J Luhmann
- Focus Programme Translational Neuroscience, University of Mainz, 55128 Mainz, Germany Institute of Physiology, University Medical Center, 55128 Mainz, Germany
| | - Sheena Pinto
- Division of Developmental Immunology, DKFZ Heidelberg, 69120 Heidelberg, Germany
| | - Joern Toedling
- Institute of Molecular Biology gGmbH, 55128 Mainz, Germany
| | - Jacqueline Trotter
- Molecular Cell Biology, University of Mainz, 55128 Mainz, Germany Focus Programme Translational Neuroscience, University of Mainz, 55128 Mainz, Germany
| | - Eva-Maria Krämer-Albers
- Molecular Cell Biology, University of Mainz, 55128 Mainz, Germany Focus Programme Translational Neuroscience, University of Mainz, 55128 Mainz, Germany
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33
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Matzarakis A, Fröhlich D. Sport events and climate for visitors--the case of FIFA World Cup in Qatar 2022. Int J Biometeorol 2015; 59:481-486. [PMID: 25119826 DOI: 10.1007/s00484-014-0886-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 08/01/2014] [Accepted: 08/01/2014] [Indexed: 06/03/2023]
Abstract
The effect of weather on sport events is not well studied. It requires special attention if the event is taking place at a time and place with extreme weather situations. For the world soccer championship in Qatar (Doha 2022), human biometeorological analysis has been performed in order to identify the time of the year that is most suitable in terms of thermal comfort for visitors attending the event. The analysis is based on thermal indices like Physiologically Equivalent Temperature (PET). The results show that this kind of event may be not appropriate for visitors, if it is placed during months with extreme conditions. For Doha, this is the period from May to September, when conditions during a large majority of hours of the day cause strong heat stress for the visitors. A more appropriate time would be the months November to February, when thermally comfortable conditions are much more frequent. The methods applied here can quantify the thermal conditions and show limitations and possibilities for specific events and locations.
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Affiliation(s)
- Andreas Matzarakis
- Faculty of Environment and Natural Resources, Albert-Ludwigs University Freiburg, 79085, Freiburg, Germany,
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34
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Abstract
A long-time water vapour stability over 700 sorption cycles is proven for the first time for a breathing MOF, here CAU-10-H.
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Affiliation(s)
- Dominik Fröhlich
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg, Germany
- Institut für Anorganische Chemie und Strukturchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf, Germany
| | | | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie
- Heinrich-Heine-Universität Düsseldorf
- 40225 Düsseldorf, Germany
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35
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Jeremias F, Fröhlich D, Janiak C, Henninger SK. Advancement of sorption-based heat transformation by a metal coating of highly-stable, hydrophilic aluminium fumarate MOF. RSC Adv 2014. [DOI: 10.1039/c4ra03794d] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A 300 μm thick, polycrystalline, thermally well coupled coating of microporous aluminium fumarate was deposited on a metal substrate and found to be stable for at least 4500 ad-/desorption cycles with water vapour.
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Affiliation(s)
- Felix Jeremias
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
- 40204 Düsseldorf, Germany
- Department of Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems (ISE)
| | - Dominik Fröhlich
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
- 40204 Düsseldorf, Germany
- Department of Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems (ISE)
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
- 40204 Düsseldorf, Germany
| | - Stefan K. Henninger
- Department of Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems (ISE)
- 79110 Freiburg, Germany
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36
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Abstract
MOFs with high water uptake capacity and hydrothermal stability are gaining attention for low temperature heat transformation applications such as thermally driven adsorption chillers or adsorption heat pumps.
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Affiliation(s)
- Felix Jeremias
- Dept. Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg, Germany
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
| | - Dominik Fröhlich
- Dept. Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg, Germany
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
| | - Christoph Janiak
- Institut für Anorganische Chemie und Strukturchemie
- Universität Düsseldorf
- 40204 Düsseldorf, Germany
| | - Stefan K. Henninger
- Dept. Thermally Active Materials and Solar Cooling
- Fraunhofer Institute for Solar Energy Systems ISE
- 79110 Freiburg, Germany
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Frühbeis C, Fröhlich D, Kuo WP, Krämer-Albers EM. Extracellular vesicles as mediators of neuron-glia communication. Front Cell Neurosci 2013; 7:182. [PMID: 24194697 PMCID: PMC3812991 DOI: 10.3389/fncel.2013.00182] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [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: 09/13/2013] [Accepted: 10/01/2013] [Indexed: 01/15/2023] Open
Abstract
In the nervous system, glia cells maintain homeostasis, synthesize myelin, provide metabolic support, and participate in immune defense. The communication between glia and neurons is essential to synchronize these diverse functions with brain activity. Evidence is accumulating that secreted extracellular vesicles (EVs), such as exosomes and shedding microvesicles, are key players in intercellular signaling. The cells of the nervous system secrete EVs, which potentially carry protein and RNA cargo from one cell to another. After delivery, the cargo has the ability to modify the target cell phenotype. Here, we review the recent advances in understanding the role of EV secretion by astrocytes, microglia, and oligodendrocytes in the central nervous system. Current work has demonstrated that oligodendrocytes transfer exosomes to neurons as a result of neurotransmitter signaling suggesting that these vesicles may mediate glial support of neurons.
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Affiliation(s)
- Carsten Frühbeis
- Department of Molecular Cell Biology, Johannes Gutenberg University Mainz Mainz, Germany
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von Jonquieres G, Mersmann N, Klugmann CB, Harasta AE, Lutz B, Teahan O, Housley GD, Fröhlich D, Krämer-Albers EM, Klugmann M. Glial promoter selectivity following AAV-delivery to the immature brain. PLoS One 2013; 8:e65646. [PMID: 23799030 PMCID: PMC3683058 DOI: 10.1371/journal.pone.0065646] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 04/11/2013] [Indexed: 11/18/2022] Open
Abstract
Recombinant adeno-associated virus (AAV) vectors are versatile tools for gene transfer to the central nervous system (CNS) and proof-of-concept studies in adult rodents have shown that the use of cell type-specific promoters is sufficient to target AAV-mediated transgene expression to glia. However, neurological disorders caused by glial pathology usually have an early onset. Therefore, modelling and treatment of these conditions require expanding the concept of targeted glial transgene expression by promoter selectivity for gene delivery to the immature CNS. Here, we have investigated the AAV-mediated green fluorescent protein (GFP) expression driven by the myelin basic protein (MBP) or glial fibrillary acidic protein (GFAP) promoters in the developing mouse brain. Generally, the extent of transgene expression after infusion at immature stages was widespread and higher than in adults. The GFAP promoter-driven GFP expression was found to be highly specific for astrocytes following vector infusion to the brain of neonates and adults. In contrast, the selectivity of the MBP promoter for oligodendrocytes was poor following neonatal AAV delivery, but excellent after vector injection at postnatal day 10. To extend these findings obtained in naïve mice to a disease model, we performed P10 infusions of AAV-MBP-GFP in aspartoacylase (ASPA)-deficient mouse mutants presenting with early onset oligodendrocyte pathology. Spread of GFP expression and selectivity for oligodendrocytes in ASPA-mutants was comparable with our observations in normal animals. Our data suggest that direct AAV infusion to the developing postnatal brain, utilising cellular promoters, results in targeted and long-term transgene expression in glia. This approach will be relevant for disease modelling and gene therapy for the treatment of glial pathology.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Nadine Mersmann
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Claudia Bettina Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Anne Editha Harasta
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Orla Teahan
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Gary David Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Dominik Fröhlich
- Department of Molecular Cell Biology, University of Mainz, Mainz, Germany
| | | | - Matthias Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
- * E-mail:
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Abstract
Brain function depends on coordinated interactions between neurons and glial cells. Recent evidence indicates that these cells release endosome-derived microvesicles termed exosomes, which are 50-100 nm in size and carry specific protein and RNA cargo. Exosomes can interact with neighboring cells raising the concept that exosomes may mediate signaling between brain cells and facilitate the delivery of bioactive molecules. Oligodendrocytes myelinate axons and furthermore maintain axonal integrity by an yet uncharacterized pathway of trophic support. Here, we highlight the role of exosomes in nervous system cell communication with particular focus on exosomes released by oligodendrocytes and their potential implications in axon-glia interaction and myelin disease, such as multiple sclerosis. These secreted vesicles may contribute to eliminate overproduced myelin membrane or to transfer antigens facilitating immune surveillance of the brain. Furthermore, there is emerging evidence that exosomes participate in axon-glia communication.
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Affiliation(s)
- Carsten Frühbeis
- Department of Molecular Cell Biology, Johannes Gutenberg University Mainz Mainz, Germany
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Affiliation(s)
- Thomas Rünzi
- Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany
| | - Dominik Fröhlich
- Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany
| | - Stefan Mecking
- Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, D-78457 Konstanz, Germany
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Abstract
PURPOSE To elucidate differential functional and phenotypic changes in response to relevant catecholamines, the generation of oxidative free radicals by PMN, and changes in the expression of L-selectin and Mac-1 on the surface of PMN were examined in the presence of epinephrine, norepinephrine and dopamine in physiological and pharmacological concentrations. MATERIALS AND METHODS Human polymorphonuclear neutrophils were obtained from healthy donors and pretreated with 0.5 nM or 500 nM epinephrine; 1.18 nM or 1 180 nM norepinephrine; or 0.26 nM or 261 nM dopamine, followed by stimulation with FMLP. Stimulated neutrophils were incubated with antibodies against CD 11 b or CD 62 l and assessed by flow cytometry. Additional probes were assessed by flow cytometry for the generation of oxidative free radicals. RESULTS All catecholamines in high concentration inhibited the suppression of CD 62 l expression and CD 11 b upregulation following stimulation with FMLP. A high concentration of epinephrine suppresses generation of oxidative free radicals. CONCLUSIONS The effect of catecholamines on the expression of CD 62 l explains the increased expression of L-selection on PMN observed after trauma. The suppression of CD 11 b reduces leukocyte adherence and consecutive abnormalities in microvascular flow. Epinephrine inhibits the generation of oxidative free radicals by PMN with potentially detrimental effects with respect to bacterial clearance.
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Affiliation(s)
- B Trabold
- Department of Anaesthesiology, University of Regensburg, Regensburg, Germany.
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Leinß S, Kampfrath T, Volkmann KV, Schmid BA, Fröhlich D, Wolf M, Kaindl RA, Leitenstorfer A, Huber R. THz quantum optics with dark excitons in Cu2O: from stimulated emission to nonlinear population control. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pssc.200879859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Trabold B, Gruber M, Fröhlich D. Synthetic inotropes inhibit the expression of adhesion molecules and augment the expression of L-selectin in polymorphonuclear neutrophils. Resuscitation 2007; 74:352-6. [PMID: 17382451 DOI: 10.1016/j.resuscitation.2007.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 12/27/2006] [Accepted: 01/11/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To elucidate differential functional and phenotypic changes in response to clinically relevant synthetic inotropes plus the generation of oxidative free radicals by polymorphonuclear neutrophils (PMN), and changes in the expression of L-selectin and Mac-1 on the surface of PMN were examined in the presence of dobutamine and dopexamine in pharmacological concentrations. DESIGN Prospective, in vitro study. SETTING Research laboratory. SUBJECTS Human PMN obtained from healthy donors. INTERVENTIONS PMN were pretreated with dobutamine 147.99 nM or 147,990 nM, or dopexamine 100 nM or 100,000 nM, followed by stimulation with FMLP. Stimulated neutrophils were incubated with antibiodies against CD11b or CD62l and assessed by flow cytometry. Additional probes were assessed by flow cytometry for the generation of oxidative free radicals. MEASUREMENTS AND MAIN RESULTS Low concentrations of both synthetic inotropes significantly inhibit the suppression of CD62l expression following stimulation with N-formyl-l-methionyl-l-leucyl-l-phenylalanine; high concentrations antagonize this effect. High concentrations of both synthetic inotropes suppresses the expression of CD11b. Neither dobutamine nor dopexamine modified the generation of oxidative free radicals. CONCLUSIONS While the upregulation of Mac-1 expression is inhibited in a dose-dependent manner, the expression of L-selectin is enhanced at low concentrations of dobutamine and dopexamine and partly counter-regulated at high concentrations. It seems that synthetic inotropes can modulate the immunomodulatory ability by inhibition of PMN rolling and modification of PMN adherence and diapedese.
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Affiliation(s)
- B Trabold
- Klinik für Anästhesiologie, Universität Regensburg, 93042 Regensburg, Germany.
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Abstract
BACKGROUND AND OBJECTIVE Propofol has been shown to inhibit a variety of functions of neutrophils in vitro, but there is a lack of in vivo data. To analyse the effects of propofol on neutrophil function in vivo we chose to investigate cataract surgery since it represents a small surgical procedure with minimal immunomodulatory effects induced by surgery. We sought to analyse any immunosuppressive effects of propofol after short-term administration in vivo in comparison to local anaesthesia as well as to in vitro effects of propofol. METHODS The study was designed as an open randomized trial enrolling 20 patients undergoing general or local anaesthesia. The neutrophil oxidative response and propofol plasma concentration were assessed prior, during and after anaesthesia. Neutrophil function was determined flow cytometrically based on dihydrorhodamine 123 oxidation. RESULTS Propofol concentrations which yielded a marked suppression in vitro did not alter the neutrophil oxidative response during cataract surgery in vivo. However, after local anaesthesia the neutrophil oxidative response declined to 37%, compared to the control response prior to anaesthesia. CONCLUSIONS Although we could detect the well established suppression of neutrophil function by propofol in vitro it was not evident in vivo. This may be due to compensating effects on neutrophil function during surgery in vivo. The decline in the neutrophil oxidative response in the local anaesthesia group might be due to increased stress and catecholamine concentrations or a direct interaction of local anaesthetics with neutrophil intracellular signalling.
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Affiliation(s)
- D Fröhlich
- University of Regensburg, Department of Anaesthesiology, Regensburg, Germany.
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Trabold B, Rothoerl R, Wittmann S, Woertgen C, Fröhlich D. Cerebrospinal fluid and neutrophil respiratory burst after subarachnoid hemorrhage. Neuroimmunomodulation 2005; 12:152-6. [PMID: 15905623 DOI: 10.1159/000084847] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Accepted: 08/11/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To investigate the effect of cerebrospinal fluid (CSF) from patients with subarachnoid hemorrhage (SAH) on the activation of polymorphonuclear neutrophils (PMN) in response to receptor-dependent stimulation with N-formyl-l-methionyl-l-leucyl-l-phenylalanine and TNFalpha or non-receptor-dependent stimulation with phorbol 12-myristate 13-acetate. METHODS CSF from 12 patients with SAH due to ruptured cerebral aneurysm was collected. Samples of CSF were drawn at different time points. CSF from 6 healthy subjects receiving spinal anesthesia served as the control group. After stimulation of PMN the generation of reactive oxygen intermediates was analyzed on a flow cytometer. RESULTS In the presence of CSF, PMN showed a significant suppression of the oxidative burst following stimulation compared to stimulation without CSF. The reduction of the oxidative burst following stimulation was higher in the presence of CSF from patients with SAH. After pretreatment at 56 degrees C, the extent of the suppression observed following receptor-dependent stimulation and CSF from patients with SAH was similar to that seen after stimulation with CSF from healthy individuals. CONCLUSIONS These data show that the presence of CSF resulted in a suppression of neutrophil oxidative function. A more distinct depression was seen in the presence of CSF from patients with SAH. We suggest a complex physiological inhibitory and protective mechanism against unfavorable activation of PMN by CSF.
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Affiliation(s)
- B Trabold
- Klinik für Anästhesiologie, Universität Regensburg, Regensburg, Deutschland.
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Wittmann S, Daniels S, Ittner KP, Fröhlich D. Thiopentone and methohexitone enantiomers do not act stereoselectively on the oxidative response in human neutrophils in vitro. Pharmacology 2004; 72:12-9. [PMID: 15292650 DOI: 10.1159/000078627] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 01/26/2004] [Indexed: 11/19/2022]
Abstract
To elucidate potential stereoselective effects of single barbiturate isomers, we compared the inhibitory potency of single thiopentone enantiomers, two isomer-enriched mixtures of methohexitone and racemic mixtures of both barbiturates on the fMLP-induced neutrophil oxidative response. A suppression of the response to 50% compared to control required a 100-fold therapeutic concentration of methohexitone, while therapeutic concentrations of the thiopentone racemate led to a significant inhibition (relative fluorescence of neutrophils 0.46 +/- 0.03 compared to fMLP controls). The racemate of thiopentone produced significantly greater inhibition than the single enantiomers. Stereoselectivity in favor of one isomer could not be shown for both barbiturates. The greater inhibition by the thiopentone racemate might suggest two separate binding sites for the enantiomers which are positively coupled.
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Affiliation(s)
- S Wittmann
- Department of Anaesthesiology, University of Regensburg, Germany.
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Wittmann S, Rothe G, Schmitz G, Fröhlich D. Cytokine upregulation of surface antigens correlates to the priming of the neutrophil oxidative burst response. Cytometry A 2004; 57:53-62. [PMID: 14699606 DOI: 10.1002/cyto.a.10108] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Neutrophil activation is strongly related to organ dysfunction that occurs during systemic inflammatory responses. The aim of our study was to analyze the oxidative burst response in correlation to the up- and downregulation of N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) receptors and the surface antigens CD11b, CD62L, and CD66b as potential surrogate markers of the degree of neutrophil priming for an increased oxidative burst response induced by proinflammatory cytokines. METHODS Blood was taken from healthy donors. Neutrophils were pretreated with cytokines (interleukin [IL]-1beta, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNFalpha]; 0.01-10 ng/ml) and stimulated with fMLP (100 nM) in vitro. Functional and phenotypical parameters were quantified flow cytometrically. RESULTS The oxidative burst response increased after priming with 0.1 ng/ml TNFalpha, 1 ng/ml GM-CSF, or 10 ng/ml IL-8. Upregulation of fMLP receptors, CD11b, and CD66b and downregulation of CD62L showed a close correlation to the oxidative burst response. Altered expression of these parameters partly reached significance at lower cytokine concentrations in comparison with the oxidative burst. IL-1beta and IL-6 had no effect. CONCLUSIONS Our results showed that the expression of phenotypical parameters closely correlates with functional parameters in human neutrophils. Thus an up- or downregulation of antigens such as CD11b or CD62L reflects cytokine-induced functional changes.
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Affiliation(s)
- S Wittmann
- Department of Anesthesiology, University of Regensburg, 93042, Germany
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Dasbach G, Fröhlich D, Stolz H, Klieber R, Suter D, Bayer M. Wave-vector-dependent exciton exchange interaction. Phys Rev Lett 2003; 91:107401. [PMID: 14525502 DOI: 10.1103/physrevlett.91.107401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2003] [Indexed: 05/24/2023]
Abstract
The exchange interaction for the yellow 1S orthoexciton in Cu2O is derived up to the order K2. The resulting exchange splittings are verified experimentally using high resolution spectroscopy. In agreement with theory the fine structure shows a characteristic dependence on the direction of the wave vector.
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Affiliation(s)
- G Dasbach
- Institut für Physik, Universität Dortmund, D-44221 Dortmund, Germany
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