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Xu Y, Wang J, Qin X, Liu J. Advances in the pathogenesis and treatment of pneumococcal meningitis. Virulence 2024; 15:2387180. [PMID: 39192572 PMCID: PMC11364070 DOI: 10.1080/21505594.2024.2387180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 07/04/2024] [Accepted: 07/28/2024] [Indexed: 08/29/2024] Open
Abstract
Streptococcus pneumoniae is a common pathogen associated with community-acquired bacterial meningitis, characterized by high morbidity and mortality rates. While vaccination reduces the incidence of meningitis, many survivors experience severe brain damage and corresponding sequelae. The pathogenesis of pneumococcal meningitis has not been fully elucidated. Currently, meningitis requires bacterial disruption of the blood - brain barrier, a process that involves the interaction of bacterial surface components with host cells and various inflammatory responses. This review delineates the global prevalence, pathogenesis, and treatment strategies of pneumococcal meningitis. The objective is to enhance the thorough comprehension of the clinical manifestations and biological mechanisms of the disease, thereby enabling more efficient prevention, diagnosis, and therapeutic interventions.
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Affiliation(s)
- Yiyun Xu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, China
| | - Ji Wang
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, China
| | - Xiaosong Qin
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, China
| | - Jianhua Liu
- Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Liaoning Clinical Research Center for Laboratory Medicine, Shenyang, China
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2
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Bjar N, Hermansson A, Gisselsson-Solen M. How common is otogenic meningitis? A retrospective study in southern Sweden over 18 years. Infection 2024; 52:1377-1384. [PMID: 38416397 PMCID: PMC11289216 DOI: 10.1007/s15010-024-02195-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/22/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Bacterial meningitis is a rare, but life-threatening disease, which sometimes occurs as a complication to acute otitis media (AOM). The proportion of meningitis cases originating from AOM is not clear. PURPOSE The aim of this study was to investigate the proportion of meningitis cases caused by AOM, to compare risk factors, bacteriology and outcome between otogenic and non-otogenic meningitis, and to analyse the incidence of bacterial meningitis after the introduction of conjugate pneumococcal vaccines (PCV). METHODS The medical charts of all patients admitted to hospitals in southern Sweden with bacterial meningitis between 2000 and 2017 were retrieved. Based on otoscopy and/or imaging, the proportion of otogenic meningitis cases was calculated, as were annual incidences. RESULTS A total of 216 patients were identified, 25 of whom died. The proportion of otogenic meningitis was 31% but varied from 6% among teenagers to 40% among adults. Before PCV, 23% of all meningitis cases were children < 2 years, compared to 1% post-PCV. The average incidence in the adult population, on the other hand, increased post-PCV, though there were large annual variations. S. pneumoniae was the most commonly identified pathogen in everyone but teenagers, in whom N. meningitidis was predominant. CONCLUSION AOM is an important cause of meningitis in children and adults. Though bacterial meningitis almost disappeared in children < 2 years after the introduction of PCV, the incidence of pneumococcal meningitis in adults seems to have increased.
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Affiliation(s)
- Nora Bjar
- Vårdcentralen Lunden, Ystadgatan 53c, 214 44, Malmö, Sweden
| | - Ann Hermansson
- Department of Otorhinolaryngology, Head and Neck Surgery, Skåne University Hospital, 221 85, Lund, Sweden
| | - Marie Gisselsson-Solen
- Department of Otorhinolaryngology, Head and Neck Surgery, Skåne University Hospital, 221 85, Lund, Sweden.
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3
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Tighilet B, Trico J, Xavier F, Chabbert C. [Animal models of balance pathologies: New tools to study peripheral vestibulopathies]. Med Sci (Paris) 2023; 39:632-642. [PMID: 37695153 DOI: 10.1051/medsci/2023097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023] Open
Abstract
The different types of peripheral vestibulopathies (PVs) or peripheral vestibular disorders (PVDs) are essentially diagnosed on the basis of their clinical expression. The heterogeneity of vestibular symptoms makes it difficult to stratify patients for therapeutic management. Animal models of PVs are a good mean to search for clinical evaluation criteria allowing to objectively analyze the kinetics of expression of the vertigo syndrome and to evaluate the benefits of therapeutic strategies, whether they are pharmacological or rehabilitative. The question of the predictability of these animal models is therefore crucial for the identification of behavioral and biological biomarkers that could then be used in the human clinic. In this review, we propose an overview of the different animal models of PVs, and discuss their relevance for the understanding of the underlying pathophysiological mechanisms and the development of new and more targeted therapeutic approaches.
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Affiliation(s)
- Brahim Tighilet
- Aix Marseille université-CNRS, Laboratoire de neurosciences cognitives, LNC UMR 7291, Marseille, France - Groupements de recherche (GDR) Vertige, Unité CNRS GDR2074, Marseille, France
| | - Jessica Trico
- Aix Marseille université-CNRS, Laboratoire de neurosciences cognitives, LNC UMR 7291, Marseille, France - Groupements de recherche (GDR) Vertige, Unité CNRS GDR2074, Marseille, France
| | - Frédéric Xavier
- Aix Marseille université-CNRS, Laboratoire de neurosciences cognitives, LNC UMR 7291, Marseille, France - Groupements de recherche (GDR) Vertige, Unité CNRS GDR2074, Marseille, France
| | - Christian Chabbert
- Aix Marseille université-CNRS, Laboratoire de neurosciences cognitives, LNC UMR 7291, Marseille, France - Groupements de recherche (GDR) Vertige, Unité CNRS GDR2074, Marseille, France
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4
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Karppinen M, Rugemalira E, Savonius O, Cruzeiro ML, Aarnisalo A, Jutila T, Pelkonen T. Auditory Steady-State Response and Hearing Impairment in Survivors of Childhood Bacterial Meningitis in Luanda, Angola. J Clin Med 2023; 12:jcm12082842. [PMID: 37109179 PMCID: PMC10143662 DOI: 10.3390/jcm12082842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/22/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
Survivors of childhood bacterial meningitis (BM) often develop hearing impairment (HI). In low- and middle-income countries (LMICs), BM continues to be a significant cause of hearing disability. We assessed hearing among BM survivors using auditory steady-state responses (ASSR), providing frequency-specific estimated audiograms, and examined whether ASSR would provide a greater understanding of BM-induced HI. Survivors from two prospective BM trials (ISRCTN62824827; NCT01540838) from Luanda Children's Hospital were examined in a follow-up visit with a median duration of 26 months after BM. The hearing of 50 BM survivors and 19 control children was evaluated using ASSR and auditory brainstem response (ABR) after interview and neurological and otorhinolaryngological examinations. The median age of survivors was 80 (IQR 86) months. We diagnosed HI (better ear hearing ≥ 26 dB) in 9/50 (18%) children. Five of the fifty survivors (10%) and 14/100 ears (14%) had profound HI (>80 dB). Severe-to-profound HI affected all frequencies steadily, affecting only the ears of BM survivors (18/100 vs. 0/38, p = 0.003). When looking only at the severely or profoundly affected ears, young age, low Glascow coma score, pneumococcal aetiology, and ataxia were associated with a worse hearing outcome.
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Affiliation(s)
- Mariia Karppinen
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
| | - Emilie Rugemalira
- Children's Hospital, Pediatric Research Center, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
| | - Okko Savonius
- Children's Hospital, Pediatric Research Center, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
| | | | - Antti Aarnisalo
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
| | - Topi Jutila
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
| | - Tuula Pelkonen
- Children's Hospital, Pediatric Research Center, University of Helsinki, Helsinki University Hospital, 00290 HUS Helsinki, Finland
- David Bernardino Children's Hospital, Rua Amilcar Cabral, Maianga, Luanda, Angola
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5
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What Predictability for Animal Models of Peripheral Vestibular Disorders? Biomedicines 2022; 10:biomedicines10123097. [PMID: 36551852 PMCID: PMC9775358 DOI: 10.3390/biomedicines10123097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022] Open
Abstract
The different clinical entities grouped under the term peripheral vestibulopathies (PVs) or peripheral vestibular disorders (PVDs) are distinguished mainly based on their symptoms/clinical expression. Today, there are very few commonly accepted functional and biological biomarkers that can confirm or refute whether a vestibular disorder belongs to a precise classification. Consequently, there is currently a severe lack of reliable and commonly accepted clinical endpoints, either to precisely follow the course of the vertigo syndrome of vestibular origin or to assess the benefits of therapeutic approaches, whether they are pharmacological or re-educational. Animal models of PV are a good means to identify biomarkers that could subsequently be exploited in human clinical practice. The question of their predictability is therefore crucial. Ten years ago, we had already raised this question. We revisit this concept today in order to take into account the animal models of peripheral vestibular pathology that have emerged over the last decade, and the new technological approaches available for the behavioral assessment of vestibular syndrome in animals and its progression over time. The questions we address in this review are the following: are animal models of PV predictive of the different types and stages of vestibular pathologies, and if so, to what extent? Are the benefits of the pharmacological or reeducational therapeutic approaches achieved on these different models of PV (in particular the effects of attenuation of the acute vertigo, or acceleration of central compensation) predictive of those expected in the vertiginous patient, and if so, to what extent?
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6
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Le ND, Steinfort M, Grandgirard D, Maleska A, Leppert D, Kuhle J, Leib SL. The CCR5 antagonist maraviroc exerts limited neuroprotection without improving neurofunctional outcome in experimental pneumococcal meningitis. Sci Rep 2022; 12:12945. [PMID: 35902720 PMCID: PMC9334283 DOI: 10.1038/s41598-022-17282-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/22/2022] [Indexed: 11/10/2022] Open
Abstract
One-third of pneumococcal meningitis (PM) survivors suffer from neurological sequelae including learning disabilities and hearing loss due to excessive neuroinflammation. There is a lack of efficacious compounds for adjuvant therapy to control this long-term consequence of PM. One hallmark is the recruitment of leukocytes to the brain to combat the bacterial spread. However, this process induces excessive inflammation, causing neuronal injury. Maraviroc (MVC)-a CCR5 antagonist-was demonstrated to inhibit leukocyte recruitment and attenuate neuroinflammation in several inflammatory diseases. Here, we show that in vitro, MVC decreased nitric oxide production in astroglial cells upon pneumococcal stimulation. In vivo, infant Wistar rats were infected with 1 × 104 CFU/ml S. pneumoniae and randomized for treatment with ceftriaxone plus MVC (100 mg/kg) or ceftriaxone monotherapy. During the acute phase, neuroinflammation in the CSF was measured and histopathological analyses were performed to determine neuronal injury. Long-term neurofunctional outcome (learning/memory and hearing capacity) after PM was assessed. MVC treatment reduced hippocampal cell apoptosis but did not affect CSF neuroinflammation and the neurofunctional outcome after PM. We conclude that MVC treatment only exerted limited effect on the pathophysiology of PM and is, therefore, not sufficiently beneficial in this experimental paradigm of PM.
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Affiliation(s)
- Ngoc Dung Le
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
| | - Marel Steinfort
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Aleksandra Maleska
- Multiple Sclerosis Centre, Neurology, Departments of Head, Spine and Neuromedicine, Biomedicine and Clinical Research, University Hospital Basel and University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - David Leppert
- Multiple Sclerosis Centre, Neurology, Departments of Head, Spine and Neuromedicine, Biomedicine and Clinical Research, University Hospital Basel and University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Jens Kuhle
- Multiple Sclerosis Centre, Neurology, Departments of Head, Spine and Neuromedicine, Biomedicine and Clinical Research, University Hospital Basel and University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.
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Persson F, Bjar N, Hermansson A, Gisselsson-Solen M. Hearing loss after bacterial meningitis, a retrospective study. Acta Otolaryngol 2022; 142:298-301. [PMID: 35404758 DOI: 10.1080/00016489.2022.2058708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND Hearing loss is a common sequela after bacterial meningitis, but risk factors for this are poorly studied, particularly in relation to concurrent acute otitis media (AOM). AIMS The aim of this study was to investigate incidence and risk factors for hearing loss in patients treated for bacterial meningitis. METHODS In this retrospective study, medical records for patients admitted to hospital with bacterial meningitis in Skåne county, Sweden, between 2000 and 2017 were retrieved. The association between risk factors and hearing loss was estimated using logistic regression. RESULTS During the 18 years, 187 cases of meningitis were identified. Hearing loss was confirmed in 71 of the 119 patients who had done an audiometry. It was significantly more common in adults. There was also evidence of an association between hearing loss and AOM, and between hearing loss and pneumococcal infection. CONCLUSION Age, concurrent AOM and pneumococcal infection were risk factors for developing hearing loss. Despite being recommended in the national guidelines, more than a third of the patients had not done a hearing test after recovering from bacterial meningitis. The findings strengthen the demand for prompt ear examination and - if needed - tympanocentesis in meningitis patients.
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Affiliation(s)
| | - Nora Bjar
- Department of Otorhinolaryngology, Head and Neck Surgery, Skåne University Hospital, Lund, Sweden
| | - Ann Hermansson
- Department of Otorhinolaryngology, Head and Neck Surgery, Skåne University Hospital, Lund, Sweden
| | - Marie Gisselsson-Solen
- Department of Otorhinolaryngology, Head and Neck Surgery, Skåne University Hospital, Lund, Sweden
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8
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Zhang L, Chen S, Sun Y. Mechanism and Prevention of Spiral Ganglion Neuron Degeneration in the Cochlea. Front Cell Neurosci 2022; 15:814891. [PMID: 35069120 PMCID: PMC8766678 DOI: 10.3389/fncel.2021.814891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 12/09/2021] [Indexed: 12/14/2022] Open
Abstract
Sensorineural hearing loss (SNHL) is one of the most prevalent sensory deficits in humans, and approximately 360 million people worldwide are affected. The current treatment option for severe to profound hearing loss is cochlear implantation (CI), but its treatment efficacy is related to the survival of spiral ganglion neurons (SGNs). SGNs are the primary sensory neurons, transmitting complex acoustic information from hair cells to second-order sensory neurons in the cochlear nucleus. In mammals, SGNs have very limited regeneration ability, and SGN loss causes irreversible hearing loss. In most cases of SNHL, SGN damage is the dominant pathogenesis, and it could be caused by noise exposure, ototoxic drugs, hereditary defects, presbycusis, etc. Tremendous efforts have been made to identify novel treatments to prevent or reverse the damage to SGNs, including gene therapy and stem cell therapy. This review summarizes the major causes and the corresponding mechanisms of SGN loss and the current protection strategies, especially gene therapy and stem cell therapy, to promote the development of new therapeutic methods.
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Affiliation(s)
- Li Zhang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sen Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Institute of Otorhinolaryngology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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9
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Erni ST, Gill JC, Palaferri C, Fernandes G, Buri M, Lazarides K, Grandgirard D, Edge ASB, Leib SL, Roccio M. Hair Cell Generation in Cochlear Culture Models Mediated by Novel γ-Secretase Inhibitors. Front Cell Dev Biol 2021; 9:710159. [PMID: 34485296 PMCID: PMC8414802 DOI: 10.3389/fcell.2021.710159] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 07/26/2021] [Indexed: 12/30/2022] Open
Abstract
Sensorineural hearing loss is prevalent within society affecting the quality of life of 460 million worldwide. In the majority of cases, this is due to insult or degeneration of mechanosensory hair cells in the cochlea. In adult mammals, hair cell loss is irreversible as sensory cells are not replaced spontaneously. Genetic inhibition of Notch signaling had been shown to induce hair cell formation by transdifferentiation of supporting cells in young postnatal rodents and provided an impetus for targeting Notch pathway with small molecule inhibitors for hearing restoration. Here, the oto-regenerative potential of different γ-secretase inhibitors (GSIs) was evaluated in complementary assay models, including cell lines, organotypic cultures of the organ of Corti and cochlear organoids to characterize two novel GSIs (CPD3 and CPD8). GSI-treatment induced hair cell gene expression in all these models and was effective in increasing hair cell numbers, in particular outer hair cells, both in baseline conditions and in response to ototoxic damage. Hair cells were generated from transdifferentiation of supporting cells. Similar findings were obtained in cochlear organoid cultures, used for the first time to probe regeneration following sisomicin-induced damage. Finally, effective absorption of a novel GSI through the round window membrane and hair cell induction was attained in a whole cochlea culture model and in vivo pharmacokinetic comparisons of transtympanic delivery of GSIs and different vehicle formulations were successfully conducted in guinea pigs. This preclinical evaluation of targeting Notch signaling with novel GSIs illustrates methods of characterization for hearing restoration molecules, enabling translation to more complex animal studies and clinical research.
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Affiliation(s)
- Silvia T Erni
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - John C Gill
- Audion Therapeutics B.V., Amsterdam, Netherlands
| | - Carlotta Palaferri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Gabriella Fernandes
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Michelle Buri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | | | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Albert S B Edge
- Massachusetts Eye and Ear, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States.,Harvard Stem Cell Institute, Cambridge, MA, United States
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Marta Roccio
- Cluster for Regenerative Neuroscience, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland.,Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland.,Department of Otorhinolaryngology, University of Zurich, Zurich, Switzerland
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10
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Lin X, Brunk MGK, Yuanxiang P, Curran AW, Zhang E, Stöber F, Goldschmidt J, Gundelfinger ED, Vollmer M, Happel MFK, Herrera-Molina R, Montag D. Neuroplastin expression is essential for hearing and hair cell PMCA expression. Brain Struct Funct 2021; 226:1533-1551. [PMID: 33844052 PMCID: PMC8096745 DOI: 10.1007/s00429-021-02269-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 03/27/2021] [Indexed: 12/25/2022]
Abstract
Hearing deficits impact on the communication with the external world and severely compromise perception of the surrounding. Deafness can be caused by particular mutations in the neuroplastin (Nptn) gene, which encodes a transmembrane recognition molecule of the immunoglobulin (Ig) superfamily and plasma membrane Calcium ATPase (PMCA) accessory subunit. This study investigates whether the complete absence of neuroplastin or the loss of neuroplastin in the adult after normal development lead to hearing impairment in mice analyzed by behavioral, electrophysiological, and in vivo imaging measurements. Auditory brainstem recordings from adult neuroplastin-deficient mice (Nptn-/-) show that these mice are deaf. With age, hair cells and spiral ganglion cells degenerate in Nptn-/- mice. Adult Nptn-/- mice fail to behaviorally respond to white noise and show reduced baseline blood flow in the auditory cortex (AC) as revealed by single-photon emission computed tomography (SPECT). In adult Nptn-/- mice, tone-evoked cortical activity was not detectable within the primary auditory field (A1) of the AC, although we observed non-persistent tone-like evoked activities in electrophysiological recordings of some young Nptn-/- mice. Conditional ablation of neuroplastin in Nptnlox/loxEmx1Cre mice reveals that behavioral responses to simple tones or white noise do not require neuroplastin expression by central glutamatergic neurons. Loss of neuroplastin from hair cells in adult NptnΔlox/loxPrCreERT mice after normal development is correlated with increased hearing thresholds and only high prepulse intensities result in effective prepulse inhibition (PPI) of the startle response. Furthermore, we show that neuroplastin is required for the expression of PMCA 2 in outer hair cells. This suggests that altered Ca2+ homeostasis underlies the observed hearing impairments and leads to hair cell degeneration. Our results underline the importance of neuroplastin for the development and the maintenance of the auditory system.
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Affiliation(s)
- Xiao Lin
- Neurogenetics Laboratory, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Michael G K Brunk
- Department System Physiology and Learning, AG CortXplorer, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Pingan Yuanxiang
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Andrew W Curran
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Enqi Zhang
- Institute of Medical Psychology, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Franziska Stöber
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
| | - Jürgen Goldschmidt
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Medical Faculty, Molecular Neuroscience, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Maike Vollmer
- Department System Physiology and Learning, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Department of Otolaryngology-Head and Neck Surgery, Otto-Von-Guericke University Magdeburg, University Hospital, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Max F K Happel
- Department System Physiology and Learning, AG CortXplorer, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Rodrigo Herrera-Molina
- Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany
- Centro Integrativo de Biología Y Química Aplicada, Universidad Bernardo O'Higgins, 8307993, Santiago, Chile
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
| | - Dirk Montag
- Neurogenetics Laboratory, Leibniz Institute for Neurobiology, Brenneckestr. 6, 39118, Magdeburg, Germany.
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11
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Roccio M. Directed differentiation and direct reprogramming: Applying stem cell technologies to hearing research. Stem Cells 2020; 39:375-388. [PMID: 33378797 DOI: 10.1002/stem.3315] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 12/26/2022]
Abstract
Hearing loss is the most widely spread sensory disorder in our society. In the majority of cases, it is caused by the loss or malfunctioning of cells in the cochlea: the mechanosensory hair cells, which act as primary sound receptors, and the connecting auditory neurons of the spiral ganglion, which relay the signal to upper brain centers. In contrast to other vertebrates, where damage to the hearing organ can be repaired through the activity of resident cells, acting as tissue progenitors, in mammals, sensory cell damage or loss is irreversible. The understanding of gene and cellular functions, through analysis of different animal models, has helped to identify causes of disease and possible targets for hearing restoration. Translation of these findings to novel therapeutics is, however, hindered by the lack of cellular assays, based on human sensory cells, to evaluate the conservation of molecular pathways across species and the efficacy of novel therapeutic strategies. In the last decade, stem cell technologies enabled to generate human sensory cell types in vitro, providing novel tools to study human inner ear biology, model disease, and validate therapeutics. This review focuses specifically on two technologies: directed differentiation of pluripotent stem cells and direct reprogramming of somatic cell types to sensory hair cells and neurons. Recent development in the field are discussed as well as how these tools could be implemented to become routinely adopted experimental models for hearing research.
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Affiliation(s)
- Marta Roccio
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich (USZ), and University of Zurich (UZH), Zurich, Switzerland
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12
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Pan SD, Grandgirard D, Leib SL. Adjuvant Cannabinoid Receptor Type 2 Agonist Modulates the Polarization of Microglia Towards a Non-Inflammatory Phenotype in Experimental Pneumococcal Meningitis. Front Cell Infect Microbiol 2020; 10:588195. [PMID: 33251159 PMCID: PMC7674855 DOI: 10.3389/fcimb.2020.588195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/14/2020] [Indexed: 12/26/2022] Open
Abstract
Background Microglia initiates and sustains the inflammatory reaction that drives the pathogenesis of pneumococcal meningitis. The expression of the G-protein cannabinoid receptor type 2 (CB2) in the brain is low, but is upregulated in glial cells during infection. Its activation down-regulates pro-inflammatory processes, driving microglia towards an anti-inflammatory phenotype. CB2 agonists are therefore therapeutic candidates in inflammatory conditions like pneumococcal meningitis. We evaluated the effects of JWH-133, a specific CB2 agonist on microglial cells, inflammation, and damage driven by S. pneumoniae in vitro and in experimental pneumococcal meningitis. Materials/methods Primary mixed glial cultures were stimulated with live or heat-inactivated S. pneumoniae, or lipopolysaccharide and treated with JWH-133 or vehicle. Nitric oxide and cytokines levels were measured in the supernatant. In vivo, pneumococcal meningitis was induced by intracisternal injection of live S. pneumoniae in 11 days old Wistar rats. Animals were treated with antibiotics (Ceftriaxone, 100 mg/kg, s.c. bid) and JWH-133 (1 mg/kg, i.p. daily) or vehicle (10% Ethanol in saline, 100 µl/25g body weight) at 18 h after infection. Brains were harvested at 24 and 42 h post infection (hpi) for histological assessment of hippocampal apoptosis and cortical damage and determination of cyto/chemokines in tissue homogenates. Microglia were characterized using Iba-1 immunostaining. Inflammation in brain homogenates was determined using membrane-based antibody arrays. Results In vitro, nitric oxide and cytokines levels were significantly lowered by JWH-133 treatment. In vivo, clinical parameters were not affected by the treatment. JWH-133 significantly lowered microglia activation assessed by quantification of cell process length and endpoints per microglia. Animals treated with JWH-133 demonstrated significantly lower parenchymal levels of chemokines (CINC-1, CINC-2α/β, and MIP-3α), TIMP-1, and IL-6 at 24 hpi, and CINC-1, MIP-1α, and IL-1α at 42 hpi. Quantitative analysis of brain damage did not reveal an effect of JWH-133. Conclusions JWH-133 attenuates microglial activation and downregulates the concentrations of pro-inflammatory mediators in pneumococcal infection in vitro and in vivo. However, we didn't observe a reduction in cortical or hippocampal injury. This data provides evidence that inhibition of microglia by adjuvant CB2 agonists therapy effectively downmodulates neuroinflammation but does not reduce brain damage in experimental pneumococcal meningitis.
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Affiliation(s)
- Steven D Pan
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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13
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Zbinden FR, De Ste Croix M, Grandgirard D, Haigh RD, Vacca I, Zamudio R, Goodall ECA, Stephan R, Oggioni MR, Leib SL. Pathogenic Differences of Type 1 Restriction-Modification Allele Variants in Experimental Listeria monocytogenes Meningitis. Front Cell Infect Microbiol 2020; 10:590657. [PMID: 33194838 PMCID: PMC7662400 DOI: 10.3389/fcimb.2020.590657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 09/25/2020] [Indexed: 11/13/2022] Open
Abstract
Background: L. monocytogenes meningoencephalitis has a mortality rate of up to 50% and neurofunctional sequelae are common. Type I restriction-modification systems (RMS) are capable of adding methyl groups to the host genome. Some contain multiple sequence recognition (hsdS) genes that recombine, resulting in distinct DNA methylation patterns and patterns of gene expression. These phenotypic switches have been linked to virulence and have recently been discovered in multiple clonal complexes of L. monocytogenes. In the present study, we investigated the significant of RMS on L. monocytogenes virulence during the acute phase of experimental meningitis. Methods: L. monocytogenes strains containing RMS systems were identified, and purified clones enriched for single hsdS alleles were isolated. In vivo, 11-day old Wistar rats were infected with an inoculum containing (a) one of 4 single RMS allele variants (A, B, C, D) treated with amoxicillin (AMX 50 mg/kg/dosis, q8h), (b) a mixture of all 4 variants with or without AMX treatment, or (c) different mixtures of 2 RMS allele variants. At selected time points after infection, clinical and inflammatory parameters, bacterial titers and brain damage were determined. Changes in the relative frequency of the occurring RMS alleles in the inoculum and in CSF or cerebellum of infected animals were analyzed by capillary electrophoresis. Results: We have identified a phase variable RMS locus within L. monocytogenes CC4 and generated stocks that stably expressed each of the possible hsdS genes within that loci. Generation of these allele variants (A, B, C, D) allowed us to determine the methylation pattern associated with each hsdS through SMRT sequencing. In vivo infections with these single allele variants revealed differences in disease severity in that C induced the worst clinical outcome and more pronounced hippocampal apoptosis; D showed the most pronounced weight loss and the highest bacterial titer in the cerebellum. A caused the least severe disease. Conclusion: We identified that L. monocytogenes expressing hsdS (A) causes less damage than when other hsdS genes are expressed. While expression of hsdSC and D worsened the outcome in L. monocytogenes meningitis. We also demonstrate a competitive advantage of variants C and B over variant A in this model. Phenotypical switching may therefore represent a mechanism of virulence regulation during the acute phase of CNS infections with L. monocytogenes.
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Affiliation(s)
- Florian R Zbinden
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Megan De Ste Croix
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Richard D Haigh
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Irene Vacca
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Roxana Zamudio
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Emily C A Goodall
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marco R Oggioni
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
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14
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Muri L, Oberhänsli S, Buri M, Le ND, Grandgirard D, Bruggmann R, Müri RM, Leib SL. Repetitive transcranial magnetic stimulation activates glial cells and inhibits neurogenesis after pneumococcal meningitis. PLoS One 2020; 15:e0232863. [PMID: 32915781 PMCID: PMC7485822 DOI: 10.1371/journal.pone.0232863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/21/2020] [Indexed: 11/19/2022] Open
Abstract
Pneumococcal meningitis (PM) causes damage to the hippocampus, a brain structure critically involved in learning and memory. Hippocampal injury-which compromises neurofunctional outcome-occurs as apoptosis of progenitor cells and immature neurons of the hippocampal dentate granule cell layer thereby impairing the regenerative capacity of the hippocampal stem cell niche. Repetitive transcranial magnetic stimulation (rTMS) harbours the potential to modulate the proliferative activity of this neuronal stem cell niche. In this study, specific rTMS protocols-namely continuous and intermittent theta burst stimulation (cTBS and iTBS)-were applied on infant rats microbiologically cured from PM by five days of antibiotic treatment. Following two days of exposure to TBS, differential gene expression was analysed by whole transcriptome analysis using RNAseq. cTBS provoked a prominent effect in inducing differential gene expression in the cortex and the hippocampus, whereas iTBS only affect gene expression in the cortex. TBS induced polarisation of microglia and astrocytes towards an inflammatory phenotype, while reducing neurogenesis, neuroplasticity and regeneration. cTBS was further found to induce the release of pro-inflammatory cytokines in vitro. We conclude that cTBS intensified neuroinflammation after PM, which translated into increased release of pro-inflammatory mediators thereby inhibiting neuroregeneration.
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Affiliation(s)
- Lukas Muri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
| | - Simone Oberhänsli
- Interfaculty Bioinformatics Unit and SIB Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - Michelle Buri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
| | - Ngoc Dung Le
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit and SIB Swiss Institute of Bioinformatics, University of Bern, Bern, Switzerland
| | - René M. Müri
- Department of Neurology, University of Bern, Bern, Switzerland
| | - Stephen L. Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- * E-mail:
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15
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Cheng YF, Tsai YH, Huang CY, Lee YS, Chang PC, Lu YC, Hsu CJ, Wu CC. Generation and pathological characterization of a transgenic mouse model carrying a missense PJVK mutation. Biochem Biophys Res Commun 2020; 532:675-681. [PMID: 32917362 DOI: 10.1016/j.bbrc.2020.07.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 01/25/2023]
Abstract
Hearing loss is the most prevalent hereditary sensory disorder in children. Approximately 2 in 1000 infants are affected by genetic hearing loss. The PJVK gene, which encodes the pejvakin protein, has been linked to autosomal recessive non-syndromic hearing loss DFNB59. Previous clinical studies have revealed that PJVK mutations might be associated with a wide spectrum of auditory manifestations, ranging from hearing loss of pure cochlear origin to that involving the retrocochlear central auditory pathway. The phenotypic variety makes the pathogenesis of this disease difficult to determine. Similarly, mouse models carrying different Pjvk defects show phenotypic variability and inconsistency. In this study, we generated a knockin mouse model carrying the c.874G > A (p.G292R) variant to model and investigate the auditory and vestibular phenotypes of DFNB59.
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Affiliation(s)
- Yen-Fu Cheng
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Otolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan; Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Hsiu Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Chun-Ying Huang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Shan Lee
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Pin-Chun Chang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ying-Chang Lu
- Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
| | - Chuan-Jen Hsu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Department of Otolaryngology, Taichung Tzu-Chi Hospital, Taichung, Taiwan.
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan; Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan.
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16
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Fisher J, Pavan C, Ohlmeier LS, Nilson B, Lundgaard I, Linder A, Bentzer P. A functional observational battery for evaluation of neurological outcomes in a rat model of acute bacterial meningitis. Intensive Care Med Exp 2020; 8:40. [PMID: 32770475 PMCID: PMC7415049 DOI: 10.1186/s40635-020-00331-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/21/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Acute bacterial meningitis is a disease with a high mortality and a high incidence of neurological sequelae in survivors. There is an acute need to develop new adjuvant therapies. To ensure that new therapies evaluated in animal models are translatable to humans, studies must evaluate clinically relevant and patient-important outcomes, including neurological symptoms and sequelae. METHODS We developed and tested a functional observational battery to quantify the severity of a variety of relevant neurological and clinical symptoms in a rat model of bacterial meningitis. The functional observational battery included symptoms relating to general clinical signs, gait and posture abnormalities, involuntary motor movements, focal neurological signs, and neuromotor abnormalities which were scored according to severity and summed to obtain a combined clinical and neurological score. To test the functional observational battery, adult Sprague-Dawley rats were infected by intracisternal injection of a clinical isolate of Streptococcus pneumoniae. Rats were evaluated for 6 days following the infection. RESULTS Pneumococcal meningitis was not lethal in this model; however, it induced severe neurological symptoms. Most common symptoms were hearing loss (75% of infected vs 0% of control rats; p = 0.0003), involuntary motor movements (75% of infected vs 0% of control rats; p = 0.0003), and gait and posture abnormality (67% of infected vs 0% of control rats; p = 0.0013). Infected rats had a higher combined score when determined by the functional observational battery than control rats at all time points (24 h 12.7 ± 4.0 vs 4.0 ± 2.0; 48 h 17.3 ± 7.1 vs 3.4 ± 1.8; 6 days 17.8 ± 7.4 vs 1.7 ± 2.4; p < 0.0001 for all). CONCLUSIONS The functional observational battery described here detects clinically relevant neurological sequelae of bacterial meningitis and could be a useful tool when testing new therapeutics in rat models of meningitis.
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Affiliation(s)
- Jane Fisher
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden.
| | - Chiara Pavan
- Center for Translational Neuromedicine, Faculties of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Luisa S Ohlmeier
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Bo Nilson
- Faculty of Medicine, Department of Laboratory Medicine, Division of Medical Microbiology Lund, Lund University, Lund, Sweden
- Clinical Microbiology, Labmedicin, Region Skåne, Lund, Sweden
| | - Iben Lundgaard
- Department of Experimental Medical Science, University of Lund, Lund, Sweden
- Wallenberg Center for Molecular Medicine, University of Lund, Lund, Sweden
| | - Adam Linder
- Faculty of Medicine, Department of Clinical Sciences Lund, Division of Infection Medicine, Lund University, Lund, Sweden
| | - Peter Bentzer
- Department of Anesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden
- Division of Anesthesia and Intensive Care, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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17
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Pauna HF, Knoll RM, Lubner RJ, Brodsky JR, Cushing SL, Hyppolito MA, Nadol JB, Remenschneider AK, Kozin ED. Histopathological changes to the peripheral vestibular system following meningitic labyrinthitis. Laryngoscope Investig Otolaryngol 2020; 5:256-266. [PMID: 32337357 PMCID: PMC7178454 DOI: 10.1002/lio2.349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/18/2019] [Accepted: 12/31/2019] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE While cochlear ossification is a common sequalae of meningitic labyrinthitis, less is known about the effects of meningitis on peripheral vestibular end organs. Herein, we investigate histopathologic changes in the peripheral vestibular system and cochlea in patients with a history of meningitic labyrinthitis. METHODS Temporal bone (TB) specimens from patients with a history of meningitis were evaluated and compared to age-matched controls. Specimens were evaluated by light microscopy and assessed for qualitative changes, including the presence of vestibular and/or cochlear endolymphatic hydrops, presence and location of inflammatory cells, new bone formation, and labyrinthitis ossificans; and quantitative changes, including Scarpa's ganglion neuron (ScGN) and spiral ganglion neuron (SGN) counts. RESULTS Fifteen TB from 10 individuals met inclusion and exclusion criteria. Presence of inflammatory cells and fibrous tissue was found in 5 TB. Of these, evidence of labyrinthitis ossificans was found in 2 TB. In the peripheral vestibular system, mild to severe degeneration of the vestibular membranous labyrinth was identified in 60% of cases (n = 9 TBs). There was a 21.2% decrease (range, 3%-64%) in the mean total count of ScGN in patients with meningitis, compared to age-matched controls. In the cochlea, there was a 45% decrease (range, 25.3%-80.9%) in the mean total count of SGN compared to age-matched controls (n = 14 TBs). CONCLUSIONS Otopathologic analysis of TB from patients with a history of meningitic labyrinthitis demonstrated distinct peripheral vestibular changes. Future research may help to delineate potential mechanisms for the observed otopathologic changes following meningitis. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Henrique F. Pauna
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck SurgeryRibeirão Preto Medical School (FMRP‐USP), University of São PauloRibeirão PretoSão PauloBrazil
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
| | - Renata M. Knoll
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Department of OtolaryngologyHarvard Medical SchoolBostonMassachusetts
| | - Rory J. Lubner
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Department of OtolaryngologyHarvard Medical SchoolBostonMassachusetts
| | - Jacob R. Brodsky
- Department of Otolaryngology and Communication EnhancementBoston Children's HospitalBostonMassachusetts
| | - Sharon L. Cushing
- Department of Otolaryngology, Head & Neck SurgeryHospital for Sick Children, University of TorontoTorontoOntarioCanada
| | - Miguel A. Hyppolito
- Department of Ophthalmology, Otorhinolaryngology and Head and Neck SurgeryRibeirão Preto Medical School (FMRP‐USP), University of São PauloRibeirão PretoSão PauloBrazil
| | - Joseph B. Nadol
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Department of OtolaryngologyHarvard Medical SchoolBostonMassachusetts
| | - Aaron K. Remenschneider
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Department of OtolaryngologyHarvard Medical SchoolBostonMassachusetts
| | - Elliott D. Kozin
- Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Otopathology Laboratory, Department of OtolaryngologyMassachusetts Eye and EarBostonMassachusetts
- Department of OtolaryngologyHarvard Medical SchoolBostonMassachusetts
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18
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Christiansen M, Jensen ES, Brandt CT, Kirchmann M. Otoacoustic emissions in patients with bacterial meningitis. Int J Audiol 2020; 59:647-653. [PMID: 32100579 DOI: 10.1080/14992027.2020.1727967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Objective: Systematic evaluation of studies using otoacoustic emissions (OAEs) to monitor cochlear damage in patients with bacterial meningitis.Design: Systematic review. This includes articles retrieved from PUBMED and EMBASE. The search-strategy was based on the PICO-model. Data processing involved Cochrane Public Health Data Extraction template in addition to assessment of risk of bias and applicability with the Second Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool.Study samples: Thirty-eight articles were identified with 6 studies comprising 391 children and 17 adult patients eligible for full assessment.Results: Studies were heterogenic and the timing of OAE was incomparable between studies. The frequency of severe loss of hearing was reported to occur between 1.6 and 21% of the patients with culture-proven meningitis. The included studies, albeit heterogenic, found OAE-screening feasible and sensitive in children recovering from bacterial meningitis.Conclusion: No children with hearing loss were reported to pass an OAE screening in any of the included studies. The timing, sensitivity and extent of sensorineural hearing loss determined by OAE could not be assessed from the included studies. Levels of risk of bias were inconsistent and the clinical feasibility for routine inclusion of patients with bacterial meningitis was uncertain. The technological development within this field implies the need for further research.
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Affiliation(s)
- Malina Christiansen
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.,Department of Oto-Rhino-Laryngology, Nordsjaellands Hospital, Hillerod, Denmark
| | | | - Christian Thomas Brandt
- Department of Infectious Diseases, Nordsjaellands Hospital, Copenhagen Denmark.,Department of Clinical Medicine, Zealand University Hospital, University of Copenhagen
| | - Malene Kirchmann
- Department of Oto-Rhino-Laryngology, Nordsjaellands Hospital, Hillerod, Denmark
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19
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Chen L, Liu Z. Downregulation of FSTL‑1 attenuates the inflammation injury during Streptococcus pneumoniae infection by inhibiting the NLRP3 and TLR4/NF‑κB signaling pathway. Mol Med Rep 2019; 20:5345-5352. [PMID: 31638229 DOI: 10.3892/mmr.2019.10752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/05/2019] [Indexed: 11/06/2022] Open
Abstract
Streptococcus pneumoniae‑induced pneumonia is a common disease and major cause of community‑acquired pneumonia. Previous studies have shown that Follistatin‑like protein 1 (FSTL‑1) serves important roles in regulating the inflammatory response. The present study aimed to investigate the effect of FSTL‑1 on the inflammatory response during S. pneumoniae infection using in vitro and in vivo models. ELISAs were used to detect the production of interleukin (IL)‑1β, tumor necrosis factor‑α and IL‑6. Western blotting and reverse transcription‑quantitative PCR were performed to determine the protein and mRNA expression of these factors. The results of the present study indicated that S. pneumoniae infection triggered a strong proinflammatory response and a high level of FSTL‑1 expression in mouse bone marrow‑derived macrophages. Moreover, FSTL‑1 may be required for the production of inflammatory factors during S. pneumoniae infection by regulating nucleotide oligomerization domain‑like receptor protein 3 in vitro and in vivo. In addition, it was found that the Toll‑like receptor 4/nuclear factor‑κB signaling pathway was involved in the inflammatory response regulated by FSTL‑1. The findings of the present study suggested that FSTL‑1 plays an important role in the inflammatory response during S. pneumoniae infection, providing a potential therapeutic target for reducing morbidity and mortality in patients with pneumonia.
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Affiliation(s)
- Liang Chen
- Department of Infectious Disease, Beijing Jishuitan Hospital, 4th Medical College of Peking University, Beijing 100096, P.R. China
| | - Zhenshe Liu
- Department of Laboratory, Xian Yang Central Hospital, Xianyang, Shaanxi 712000, P.R. China
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20
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Sung CYW, Seleme MC, Payne S, Jonjic S, Hirose K, Britt W. Virus-induced cochlear inflammation in newborn mice alters auditory function. JCI Insight 2019; 4:128878. [PMID: 31484824 DOI: 10.1172/jci.insight.128878] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 08/01/2019] [Indexed: 02/06/2023] Open
Abstract
Although human cytomegalovirus (HCMV) is a known cause of sensorineural hearing loss in infants with congenital HCMV (cCMV) infections, mechanisms that contribute to sensorineural hearing loss (SNHL) in infants with cCMV infection are not well defined. Using a murine model of CMV infection during auditory development, we have shown that peripheral infection of newborn mice with murine CMV (MCMV) results in focal infection of the cochlea and virus-induced cochlear inflammation. Approximately 50%-60% of infected mice exhibited increased auditory brainstem response (ABR) thresholds across a range of sound frequencies. Histological analyses of the cochlea in MCMV-infected mice with elevated ABR thresholds revealed preservation of hair cell (HC) number and morphology in the organ of Corti. In contrast, the number of spiral ganglion neurons (SGN), synapses, and neurites connecting the cochlear HC and SGN nerve terminals were decreased. Decreasing cochlear inflammation by corticosteroid treatment of MCMV-infected mice resulted in preservation of SGN and improved auditory function. These findings show that virus-induced cochlear inflammation during early auditory development, rather than direct virus-mediated damage, could contribute to histopathology in the cochlea and altered auditory function without significant loss of HCs in the sensory epithelium.
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Affiliation(s)
| | - Maria C Seleme
- Department of Pediatrics, University of Alabama School of Medicine, Birmingham, Alabama, USA
| | - Shelby Payne
- Department of Otolaryngology, Washington University, St. Louis, Missouri, USA
| | - Stipan Jonjic
- Department of Histology and Embryology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Keiko Hirose
- Department of Otolaryngology, Washington University, St. Louis, Missouri, USA
| | - William Britt
- Department of Microbiology and.,Department of Pediatrics, University of Alabama School of Medicine, Birmingham, Alabama, USA.,Department of Neurobiology, University of Alabama School of Medicine, Birmingham, Alabama, USA
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21
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Muri L, Leppert D, Grandgirard D, Leib SL. MMPs and ADAMs in neurological infectious diseases and multiple sclerosis. Cell Mol Life Sci 2019; 76:3097-3116. [PMID: 31172218 PMCID: PMC7079810 DOI: 10.1007/s00018-019-03174-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 05/23/2019] [Accepted: 05/29/2019] [Indexed: 12/24/2022]
Abstract
Metalloproteinases-such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinases (ADAMs)-are involved in various diseases of the nervous system but also contribute to nervous system development, synaptic plasticity and neuroregeneration upon injury. MMPs and ADAMs proteolytically cleave many substrates including extracellular matrix components but also signaling molecules and receptors. During neuroinfectious disease with associated neuroinflammation, MMPs and ADAMs regulate blood-brain barrier breakdown, bacterial invasion, neutrophil infiltration and cytokine signaling. Specific and broad-spectrum inhibitors for MMPs and ADAMs have experimentally been shown to decrease neuroinflammation and brain damage in diseases with excessive neuroinflammation as a common denominator, such as pneumococcal meningitis and multiple sclerosis, thereby improving the disease outcome. Timing of metalloproteinase inhibition appears to be critical to effectively target the cascade of pathophysiological processes leading to brain damage without inhibiting the neuroregenerative effects of metalloproteinases. As the critical role of metalloproteinases in neuronal repair mechanisms and regeneration was only lately recognized, the original idea of chronic MMP inhibition needs to be conceptually revised. Recently accumulated research urges for a second chance of metalloproteinase inhibitors, which-when correctly applied and dosed-harbor the potential to improve the outcome of different neuroinflammatory diseases.
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Affiliation(s)
- Lukas Muri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Freiestrasse 1, 3012, Bern, Switzerland
| | - David Leppert
- Department of Neurology, University Hospital Basel, Petersgraben 4, 4031, Basel, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001, Bern, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001, Bern, Switzerland.
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22
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Muri L, Le ND, Zemp J, Grandgirard D, Leib SL. Metformin mediates neuroprotection and attenuates hearing loss in experimental pneumococcal meningitis. J Neuroinflammation 2019; 16:156. [PMID: 31351490 PMCID: PMC6660697 DOI: 10.1186/s12974-019-1549-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/18/2019] [Indexed: 12/16/2022] Open
Abstract
Background Pneumococcal meningitis is associated with high risk of neurological sequelae such as cognitive impairment and hearing loss. These sequelae are due to parenchymal brain and inner ear damage primarily induced by the excessive inflammatory reaction in response to bacterial brain invasion. Metformin—a biguanide drug to treat diabetes mellitus type 2—was recently found to suppress neuroinflammation and induce neuroregeneration. This study evaluated the effect of metformin adjunctive to antibiotics on neuroinflammation, brain and inner ear damage, and neurofunctional outcome in experimental pediatric pneumococcal meningitis. Methods Eleven-day-old Wistar rats were infected intracisternally with 5.22 ± 1.27 × 103 CFU Streptococcus pneumoniae and randomized for treatment with metformin (50 mg/kg, i.p., once daily for 3 weeks) plus ceftriaxone (100 mg/kg, i.p., bid, n = 61) or ceftriaxone monotherapy (n = 79). Cortical damage and hippocampal apoptosis were evaluated histomorphometrically 42 h post infection. Cerebrospinal fluid cytokine levels were analyzed during acute infection. Five weeks post infection, auditory brainstem responses were measured to determine hearing thresholds. Spiral ganglion neuron density and abundance of recently proliferated and integrated hippocampal granule neurons were assessed histologically. Additionally, the anti-inflammatory effect of metformin was studied in primary rat astroglial cells in vitro. Results Upon pneumococcal infection, metformin treatment significantly reduced levels of inflammatory cytokines and nitric oxide production in cerebrospinal fluid and in astroglial cell cultures in vitro (p < 0.05). Compared to animals receiving ceftriaxone monotherapy, adjunctive metformin significantly reduced cortical necrosis (p < 0.02) during acute infection and improved median click-induced hearing thresholds (60 dB vs. 100 dB, p < 0.002) 5 weeks after infection. Adjuvant metformin significantly improved pure tone hearing thresholds at all assessed frequencies compared to ceftriaxone monotherapy (p < 0.05) and protected from PM-induced spiral ganglion neuron loss in the inner ear (p < 0.05). Conclusion Adjuvant metformin reduces brain injury during pneumococcal meningitis by decreasing the excessive neuroinflammatory response. Furthermore, it protects spiral ganglion neurons in the inner ear and improves hearing impairments after experimental pneumococcal meningitis. These results identify adjuvant metformin as a promising therapeutic option to improve the outcome after pediatric pneumococcal meningitis. Electronic supplementary material The online version of this article (10.1186/s12974-019-1549-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lukas Muri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Mittelstrasse 43, 3012, Bern, Switzerland
| | - Ngoc Dung Le
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Mittelstrasse 43, 3012, Bern, Switzerland
| | - Jonas Zemp
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3010, Bern, Switzerland.
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23
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Combining Ceftriaxone with Doxycycline and Daptomycin Reduces Mortality, Neuroinflammation, Brain Damage, and Hearing Loss in Infant Rat Pneumococcal Meningitis. Antimicrob Agents Chemother 2019; 63:AAC.00220-19. [PMID: 31061158 DOI: 10.1128/aac.00220-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/30/2019] [Indexed: 02/07/2023] Open
Abstract
Despite appropriate antibiotic therapy, pneumococcal meningitis (PM) is associated with a case fatality rate of up to 30% in high-income countries. Survivors often suffer from severe lifelong disabilities. An excessive inflammatory reaction drives the pathophysiology, leading to brain damage and neurologic sequelae. We aimed to improve the outcome of experimental PM by simultaneously targeting different pathophysiological mechanisms with combined adjunctive therapies previously shown to be neuroprotective. In vitro, the anti-inflammatory effects of doxycycline and daptomycin were evaluated on primary rat astroglial cells stimulated with Streptococcus pneumoniae Eleven-day-old infant Wistar rats were infected intracisternally with S. pneumoniae and randomized for treatment with ceftriaxone or combination adjuvant therapy consisting of ceftriaxone, daptomycin, and doxycycline. During acute PM, combined-adjuvant therapy with ceftriaxone, daptomycin, and doxycycline increased the survival rate from 64.1% to 85.8% (P < 0.01) and alleviated weight loss compared to ceftriaxone monotherapy (P < 0.01). Levels of inflammatory cytokines were significantly reduced by combined-adjuvant therapy in vitro (P < 0.0001) and in cerebrospinal fluid in vivo (P < 0.05). In infected animals treated with combined adjunctive therapy, cortical damage was significantly reduced (P < 0.05), and animals showed a trend toward better hearing capacity 3 weeks after the infection (P = 0.089), an effect which was significant in mildly infected animals (48 decibels [dB] versus 67.22 dB; P < 0.05). These mildly infected animals showed significantly reduced cochlear fibrous occlusion (P < 0.01). By combining nonbacteriolytic daptomycin and anti-inflammatory doxycycline with ceftriaxone, the previously reported beneficial effects of the drugs were cumulated and identified the triple-antibiotic therapy as a promising therapeutic option for pediatric PM.
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24
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Wang W, Zhang LS, Zinsmaier AK, Patterson G, Leptich EJ, Shoemaker SL, Yatskievych TA, Gibboni R, Pace E, Luo H, Zhang J, Yang S, Bao S. Neuroinflammation mediates noise-induced synaptic imbalance and tinnitus in rodent models. PLoS Biol 2019; 17:e3000307. [PMID: 31211773 PMCID: PMC6581239 DOI: 10.1371/journal.pbio.3000307] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 05/16/2019] [Indexed: 12/20/2022] Open
Abstract
Hearing loss is a major risk factor for tinnitus, hyperacusis, and central auditory processing disorder. Although recent studies indicate that hearing loss causes neuroinflammation in the auditory pathway, the mechanisms underlying hearing loss–related pathologies are still poorly understood. We examined neuroinflammation in the auditory cortex following noise-induced hearing loss (NIHL) and its role in tinnitus in rodent models. Our results indicate that NIHL is associated with elevated expression of proinflammatory cytokines and microglial activation—two defining features of neuroinflammatory responses—in the primary auditory cortex (AI). Genetic knockout of tumor necrosis factor alpha (TNF-α) or pharmacologically blocking TNF-α expression prevented neuroinflammation and ameliorated the behavioral phenotype associated with tinnitus in mice with NIHL. Conversely, infusion of TNF-α into AI resulted in behavioral signs of tinnitus in both wild-type and TNF-α knockout mice with normal hearing. Pharmacological depletion of microglia also prevented tinnitus in mice with NIHL. At the synaptic level, the frequency of miniature excitatory synaptic currents (mEPSCs) increased and that of miniature inhibitory synaptic currents (mIPSCs) decreased in AI pyramidal neurons in animals with NIHL. This excitatory-to-inhibitory synaptic imbalance was completely prevented by pharmacological blockade of TNF-α expression. These results implicate neuroinflammation as a therapeutic target for treating tinnitus and other hearing loss–related disorders. Prolonged exposure to loud noises causes neuronal hyperexcitability and increases the risk of tinnitus. This study reveals that this type of tinnitus is mediated by noise-induced neuroinflammation; blockade of neuroinflammatory responses prevents noise-induced neuronal excitation/inhibition imbalance and tinnitus.
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Affiliation(s)
- Weihua Wang
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Li. S. Zhang
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Alexander K. Zinsmaier
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Genevieve Patterson
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Emily Jean Leptich
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Savannah L. Shoemaker
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Tatiana A. Yatskievych
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
| | - Robert Gibboni
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Edward Pace
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
| | - Hao Luo
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
| | - Jinsheng Zhang
- Department of Otolaryngology, Wayne State University, Detroit, Michigan, United States of America
- Department of Communication Sciences and Disorders, Wayne State University, Detroit, Michigan, United States of America
| | - Sungchil Yang
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
- Department of Biomedical Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Shaowen Bao
- Department of Physiology, University of Arizona, Tucson, Arizona, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
- * E-mail:
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25
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Erni ST, Fernandes G, Buri M, Perny M, Rutten RJ, van Noort JM, Senn P, Grandgirard D, Roccio M, Leib SL. Anti-inflammatory and Oto-Protective Effect of the Small Heat Shock Protein Alpha B-Crystallin (HspB5) in Experimental Pneumococcal Meningitis. Front Neurol 2019; 10:570. [PMID: 31244750 PMCID: PMC6573805 DOI: 10.3389/fneur.2019.00570] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/15/2019] [Indexed: 12/18/2022] Open
Abstract
Sensorineural hearing loss is the most common long-term deficit after pneumococcal meningitis (PM), occurring in up to 30% of surviving patients. The infection and the following overshooting inflammatory host response damage the vulnerable sensory cells of the inner ear, resulting in loss of hair cells and spiral ganglion neurons, ultimately leading to elevated hearing thresholds. Here, we tested the oto-protective properties of the small heat shock protein alpha B-crystallin (HspB5) with previously reported anti-inflammatory, anti-apoptotic and neuroprotective functions, in an experimental model of PM-induced hearing loss. We analyzed the effect of local and systemic delivery of HspB5 in an infant rat model of PM, as well as ex vivo, using whole mount cultures. Cytokine secretion profile, hearing thresholds and inner ear damage were assessed at predefined stages of the disease up to 1 month after infection. PM was accompanied by elevated pro-inflammatory cytokine concentrations in the cerebrospinal fluid (CSF), leukocyte and neutrophil infiltration in the perilymphatic spaces of the cochlea with neutrophils extracellular trap formation during the acute phase of the disease. Elevated hearing thresholds were measured after recovery from meningitis. Intracisternal but not intraperitoneal administration of HspB5 significantly reduced the levels of TNF-α, IL-6 IFN-γ and IL-10 in the acute phase of the disease. This resulted in a greater outer hair cell survival, as well as improved hearing thresholds at later stages. These results suggest that high local concentrations of HspB5 are needed to prevent inner ear damage in acute PM. HspB5 represents a promising therapeutic option to improve the auditory outcome and counteract hearing loss after PM.
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Affiliation(s)
- Silvia T Erni
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, DBMR, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Gabriella Fernandes
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, DBMR, University of Bern, Bern, Switzerland
| | - Michelle Buri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland
| | - Michael Perny
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, DBMR, University of Bern, Bern, Switzerland
| | | | | | - Pascal Senn
- Service d'oto-rhino-laryngologie (ORL) et de chirurgie cervico-faciale, Département des Neurosciences Cliniques, Hôpitaux Universitaires de Genève, Geneva, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland
| | - Marta Roccio
- Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland.,Laboratory of Inner Ear Research, DBMR, University of Bern, Bern, Switzerland.,Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital, Bern, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.,Cluster for Regenerative Neuroscience, DBMR, University of Bern, Bern, Switzerland
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26
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Abbas L, Rivolta MN. The use of animal models to study cell transplantation in neuropathic hearing loss. Hear Res 2019; 377:72-87. [DOI: 10.1016/j.heares.2019.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 01/29/2023]
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27
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Nogué MR, Arraiz IG, Martín GA, Valle MMF, Peligros AG. [Austrian syndrome: A rare manifestation of invasive pneumococcal disease. A case report and bibliographic review]. REVISTA ESPANOLA DE QUIMIOTERAPIA : PUBLICACION OFICIAL DE LA SOCIEDAD ESPANOLA DE QUIMIOTERAPIA 2019; 32:98-113. [PMID: 30880376 PMCID: PMC6441982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Austrian syndrome is a pathology caused by disseminated Streptococcus pneumoniae infection and characterized for the triad of pneumonia, endocarditis and meningitis. It has an estimated incidence of 0.9-7.8 cases per ten millions people each year, and a mortality of 32%. Alcohol abuse, as the main risk factor, appears only in four out of ten patients. Moreover, 14% of patientes do not have any risk factor. Two out of three patients are males and it occurs in the middle aged of life. It is more frequently on native valve, aortic valve is injured in the half of the cases. Severe regurgitation occurs in two per three patients. Appropriate antimicrobial treatment and early endocarditis surgery decrease mortality. It is possible that Austrian syndrome epidemiology is changing by the introduction of 13-valent pneumococcal conjugated vaccine in the children´s calendar.
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28
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Muri L, Grandgirard D, Buri M, Perny M, Leib SL. Combined effect of non-bacteriolytic antibiotic and inhibition of matrix metalloproteinases prevents brain injury and preserves learning, memory and hearing function in experimental paediatric pneumococcal meningitis. J Neuroinflammation 2018; 15:233. [PMID: 30131074 PMCID: PMC6103863 DOI: 10.1186/s12974-018-1272-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/08/2018] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Pneumococcal meningitis is associated with high mortality and morbidity rates. Up to 50% of survivors show neurologic sequelae including hearing loss, cognitive impairments and learning disabilities, being particularly detrimental in affected infants and children where adjuvant therapy with dexamethasone has no proven beneficial effect. We evaluated the effect of concomitantly targeting specific pathophysiological mechanisms responsible for brain damage-i.e. matrix-metalloproteinase (MMP) activity and the exacerbated cerebral inflammation provoked through antibiotic-induced bacterial lysis. Here, we combined adjunctive therapies previously shown to be neuroprotective when used as single adjuvant therapies. METHODS Eleven-day-old Wistar rats were infected intracisternally with 6.44 ± 2.17 × 103 CFU Streptococcus pneumoniae and randomised for treatment with ceftriaxone combined with (a) single adjuvant therapy with daptomycin (n = 24), (b) single adjuvant therapy with Trocade (n = 24), (c) combined adjuvant therapy (n = 66) consisting of daptomycin and Trocade, or (d) ceftriaxone monotherapy (n = 42). Clinical parameters and inflammatory CSF cytokine levels were determined during acute meningitis. Cortical damage and hippocampal apoptosis were assessed 42 h after infection. Morris water maze and auditory brainstem responses were used to assess neurofunctional outcome 3 weeks after infection. RESULTS We found significantly reduced apoptosis in the hippocampal subgranular zone in infant rats receiving adjuvant Trocade (p < 0.01) or combined adjuvant therapy (p < 0.001). Cortical necrosis was significantly reduced in rats treated with adjuvant daptomycin (p < 0.05) or combined adjuvant therapy (p < 0.05) compared to ceftriaxone monotherapy. Six hours after treatment initiation, CSF cytokine levels were significantly reduced for TNF-α (p < 0.01), IL-1β (p < 0.01), IL-6 (p < 0.001) and IL-10 (p < 0.01) in animals receiving combined adjuvant intervention compared to ceftriaxone monotherapy. Importantly, combined adjuvant therapy significantly improved learning and memory performance in infected animals and reduced hearing loss (77.14 dB vs 60.92 dB, p < 0.05) by preserving low frequency hearing capacity, compared to ceftriaxone monotherapy. CONCLUSION Combined adjuvant therapy with the non-bacteriolytic antibiotic daptomycin and the MMP inhibitor Trocade integrates the neuroprotective effects of both single adjuvants in experimental paediatric pneumococcal meningitis by reducing neuroinflammation and brain damage, thereby improving neurofunctional outcome. This strategy represents a promising therapeutic option to improve the outcome of paediatric patients suffering from pneumococcal meningitis.
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Affiliation(s)
- Lukas Muri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences (GCB), University of Bern, Freiestrasse 1, 3012 Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland
| | - Michelle Buri
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland
| | - Michael Perny
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland
| | - Stephen L. Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland
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29
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Schiavon E, Smalley JL, Newton S, Greig NH, Forsythe ID. Neuroinflammation and ER-stress are key mechanisms of acute bilirubin toxicity and hearing loss in a mouse model. PLoS One 2018; 13:e0201022. [PMID: 30106954 PMCID: PMC6091913 DOI: 10.1371/journal.pone.0201022] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 07/07/2018] [Indexed: 12/01/2022] Open
Abstract
Hyperbilirubinemia (jaundice) is caused by raised levels of unconjugated bilirubin in the blood. When severe, susceptible brain regions including the cerebellum and auditory brainstem are damaged causing neurological sequelae such as ataxia, hearing loss and kernicterus. The mechanism(s) by which bilirubin exerts its toxic effect have not been completely understood to date. In this study we investigated the acute mechanisms by which bilirubin causes the neurotoxicity that contributes to hearing loss. We developed a novel mouse model that exhibits the neurological features seen in human Bilirubin-Induced Neurological Dysfunction (BIND) syndrome that we assessed with a behavioural score and auditory brainstem responses (ABR). Guided by initial experiments applying bilirubin to cultured cells in vitro, we performed whole genome gene expression measurements on mouse brain tissue (cerebellum and auditory brainstem) following bilirubin exposure to gain mechanistic insights into biochemical processes affected, and investigated further using immunoblotting. We then compared the gene changes induced by bilirubin to bacterial lipopolysaccharide (LPS), a well characterized inducer of neuroinflammation, to assess the degree of similarity between them. Finally, we examined the extent to which genetic perturbation of inflammation and both known and novel anti-inflammatory drugs could protect hearing from bilirubin-induced toxicity. The in vitro results indicated that bilirubin induces changes in gene expression consistent with endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR). These gene changes were similar to the gene expression signature of thapsigargin–a known ER stress inducer. It also induced gene expression changes associated with inflammation and NF-κB activation. The in vivo model showed behavioural impairment and a raised auditory threshold. Whole genome gene expression analysis confirmed inflammation as a key mechanism of bilirubin neurotoxicity in the auditory pathway and shared gene expression hallmarks induced by exposure to bacterial lipopolysaccharide (LPS) a well-characterized inducer of neuroinflammation. Interestingly, bilirubin caused more severe damage to the auditory system than LPS in this model, but consistent with our hypothesis of neuroinflammation being a primary part of bilirubin toxicity, the hearing loss was protected by perturbing the inflammatory response. This was carried out genetically using lipocalin-2 (LCN2)-null mice, which is an inflammatory cytokine highly upregulated in response to bilirubin. Finally, we tested known and novel anti-inflammatory compounds (interfering with NF-κB and TNFα signalling), and also demonstrated protection of the auditory system from bilirubin toxicity. We have developed a novel, reversible, model for jaundice that shows movement impairment and auditory loss consistent with human symptoms. We used this model to establish ER-stress and inflammation as major contributors to bilirubin toxicity. Because of the rapid and reversible onset of toxicity in this novel model it represents a system to screen therapeutic compounds. We have demonstrated this by targeting inflammation genetically and with anti-inflammatory small molecules that offered protection against bilirubin toxicity. This also suggests that anti-inflammatory drugs could be of therapeutic use in hyperbilirubinemia.
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Affiliation(s)
- Emanuele Schiavon
- Department Neuroscience, Psychology & Behaviour, University of Leicester, Leicester, Leicestershire, United Kingdom
| | - Joshua L. Smalley
- Department Neuroscience, Psychology & Behaviour, University of Leicester, Leicester, Leicestershire, United Kingdom
| | - Sherylanne Newton
- Department Neuroscience, Psychology & Behaviour, University of Leicester, Leicester, Leicestershire, United Kingdom
| | - Nigel H. Greig
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, NIH, Baltimore, MD, United States of America
| | - Ian D. Forsythe
- Department Neuroscience, Psychology & Behaviour, University of Leicester, Leicester, Leicestershire, United Kingdom
- * E-mail:
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30
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Ren Y, Stankovic KM. The Role of Tumor Necrosis Factor Alpha (TNFα)in Hearing Loss and Vestibular Schwannomas. CURRENT OTORHINOLARYNGOLOGY REPORTS 2018; 6:15-23. [PMID: 31485383 DOI: 10.1007/s40136-018-0186-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Purpose of review The aim of this review is to highlight relevant literature on the role of tumor necrosis factor alpha (TNFα) in sensorineural hearing loss (SNHL) and vestibular schwannomas (VS). Recent Findings A comprehensive review of publically available databases including PubMed was performed. The mechanism by which hearing loss occurs in VS is still unknown and likely multifactorial. Genetic differences between VSs and tumor secreted proteins may be responsible, at least in part, for VS-associated SNHL. TNFα has pleotropic roles in promoting inflammation, maintaining cellular homeostasis, inducing apoptosis, and mediating ototoxicity in patients with sporadic VS. TNFα-targeted therapies have shown efficacy in both animal models of sensorineural hearing loss and clinical trials in patients with immune-mediated hearing loss. Efforts are underway to develop novel nanotechnology-based methods to target TNFα and other pathogenic molecules in VS. Summary Development of molecularly targeted therapies against TNFα represents an important area of research in ameliorating VS-associated hearing loss.
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Affiliation(s)
- Yin Ren
- Department of Otolaryngology, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | - Konstantina M Stankovic
- Department of Otolaryngology, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114, USA.,Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA.,Eaton Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114, USA.,Harvard Program in Speech and Hearing Bioscience and Technology, 25 Shattuck Street, Boston, MA 02115, USA
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31
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Perny M, Solyga M, Grandgirard D, Roccio M, Leib SL, Senn P. Streptococcus pneumoniae-induced ototoxicity in organ of Corti explant cultures. Hear Res 2017; 350:100-109. [PMID: 28460251 DOI: 10.1016/j.heares.2017.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 04/11/2017] [Accepted: 04/23/2017] [Indexed: 12/20/2022]
Abstract
Hearing loss remains the most common long-term complication of pneumococcal meningitis (PM) reported in up to 30% of survivors. Streptococcus pneumoniae have been shown to possess different ototoxic properties. Here we present a novel ex vivo experimental setup to examine in detail the pattern of hair cell loss upon exposure to different S. pneumoniae strains, therefore recapitulating pathogen derived aspects of PM-induced hearing loss. Our results show a higher susceptibility towards S. pneumoniae-induced cochlear damage for outer hair cells (OHC) compared to inner hair cells (IHC), which is consistent with in vivo data. S. pneumoniae-induced hair cell loss was both time and dose-dependent. Moreover, we have found significant differences in the level of cell damage between tissue from the basal and the apical turns. This shows that the higher vulnerability of hair cells located at high frequency regions observed in vivo cannot be explained solely by the spatial organisation and bacterial infiltration from the basal portion of the cochlea. Using a wild type D39 strain and a mutant defective for the pneumolysin (PLY) gene, we also have shown that the toxin PLY is an important factor involved in ototoxic damages. The obtained results indicate that PLY can cause both IHC and OHC loss. Finally, we are reporting here for the first time a higher vulnerability of HC located at the basal and middle cochlear region to pneumolysin-induced damage. The detailed description of the susceptibility of hair cells to Streptococcus pneumoniae provided in this report can in the future determine the choice and the development of novel otoprotective therapies during pneumococcal meningitis.
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Affiliation(s)
- Michael Perny
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Switzerland; Inner Ear Research Laboratory, Department of Otorhinolaryngology, Head& Neck Surgery, Inselspital Bern and Department of Clinical Research, University of Bern, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland
| | - Magdalena Solyga
- Inner Ear Research Laboratory, Department of Otorhinolaryngology, Head& Neck Surgery, Inselspital Bern and Department of Clinical Research, University of Bern, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland
| | - Marta Roccio
- Inner Ear Research Laboratory, Department of Otorhinolaryngology, Head& Neck Surgery, Inselspital Bern and Department of Clinical Research, University of Bern, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of Bern, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland.
| | - Pascal Senn
- Inner Ear Research Laboratory, Department of Otorhinolaryngology, Head& Neck Surgery, Inselspital Bern and Department of Clinical Research, University of Bern, Switzerland; Department of Otorhinolaryngology, Head & Neck Surgery, University Hospital Geneva (HUG), Genève, Switzerland; Cluster for Regenerative Neuroscience, Department of Clinical Research, University of Bern, Switzerland.
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