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Li P, Qian T, Sun S. Spatial architecture of the cochlear immune microenvironment in noise-induced and age-related sensorineural hearing loss. Int Immunopharmacol 2023; 114:109488. [PMID: 36470117 DOI: 10.1016/j.intimp.2022.109488] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022]
Abstract
The cochlea encodes sound stimuli and transmits them to the central nervous system, and damage to sensory cells and synapses in the cochlea leads to hearing loss. The inner ear was previously considered to be an immune privileged organ to protect the auditory organ from reactions with the immune system. However, recent studies have revealed the presence of resident macrophages in the cochlea, especially in the spiral ligament, spiral ganglion, and stria vascularis. The tissue-resident macrophages are responsible for the detection, phagocytosis, and clearance of cellular debris and pathogens from the tissues, and they initiate inflammation and influence tissue repair by producing inflammatory cytokines and chemokines. Insult to the cochlea can activate the cochlear macrophages to initiate immune responses. In this review, we describe the distribution and functions of cochlear macrophages in noise-induced hearing impairment and age-related hearing disabilities. We also focus on potential therapeutic interventions concerning hearing loss by modulating local immune responses.
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Affiliation(s)
- Peifan Li
- ENT Institute and Otorhinolaryngology, Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Eye and ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Tingting Qian
- ENT Institute and Otorhinolaryngology, Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Eye and ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Shan Sun
- ENT Institute and Otorhinolaryngology, Department of Affiliated Eye and ENT Hospital, Key Laboratory of Hearing Medicine of NHFPC, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China; Eye and ENT Hospital, Fudan University, Shanghai, 200031, China.
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2
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Kloos B, Bertlich M, Spiegel JL, Freytag S, Lauer SK, Canis M, Weiss BG, Ihler F. Low Dose Betahistine in Combination With Selegiline Increases Cochlear Blood Flow in Guinea Pigs. Ann Otol Rhinol Laryngol 2022; 132:519-526. [PMID: 35656811 PMCID: PMC10108341 DOI: 10.1177/00034894221098803] [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: 11/17/2022]
Abstract
OBJECTIVE Betahistine is frequently used in the pharmacotherapy for Menière's Disease (MD). Little is known about its mode of action and prescribed dosages vary. While betahistine had an increasing effect on cochlear microcirculation in earlier studies, low dose betahistine of 0.01 mg/kg bw or less was not able to effect this. Selegiline inhibits monoaminooxidase B and therefore potentially the breakdown of betahistine. The goal of this study was to examine whether the addition of selegiline to low dose betahistine leads to increased cochlear blood flow. METHODS Twelve Dunkin-Hartley guinea pigs were anesthetized, the cochlea was exposed and a window opened to the stria vascularis. Blood plasma was visualized by injecting fluoresceinisothiocyanate-dextrane and vessel diameter and erythrocyte velocity were evaluated over 20 minutes. One group received low dose betahistine (0.01 mg/kg bw) and selegiline (1 mg/kg bw) i.v. while the other group received only selegiline (1 mg/kg bw) and saline (0.9% NaCl) as placebo i.v. RESULTS Cochlear microcirculation increased significantly (P < .001) in guinea pigs treated with low dose betahistine combined with selegiline by up to 58.3 ± 38.7% above baseline over a period of up to 11 minutes. In one guinea pig, the increase was 104.6%. Treatment with Selegiline alone did not affect microcirculation significantly. CONCLUSIONS Low dose betahistine increased cochlear microcirculation significantly when combined with selegiline. This should be investigated in further studies regarding dose-effect relation in comparison to betahistine alone. Side effects, in particular regarding circulation, should be considered carefully in view of the clinical applicability of a combination therapy in patients with MD.
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Affiliation(s)
- Benedikt Kloos
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany.,Institute of Surgical Research, Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany.,German Center for Vertigo and Dizziness (DSGZ), LMU Munich, Munich, Germany
| | - Mattis Bertlich
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany.,Department of Dermatology and Allergy, University Hospital, LMU Munich, Munich, Germany
| | - Jennifer L Spiegel
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Saskia Freytag
- Molecular Medicine, Harry Perkins Institute of Medical Research, Perth, WA, Australia
| | - Susanne K Lauer
- Clinic for Small Animal Surgery and Reproduction, LMU Munich, Munich, Germany
| | - Martin Canis
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Bernhard G Weiss
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany
| | - Friedrich Ihler
- Department of Otorhinolaryngology, University Hospital, LMU Munich, Munich, Germany.,Institute of Surgical Research, Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany.,German Center for Vertigo and Dizziness (DSGZ), LMU Munich, Munich, Germany.,Department of Ear, Nose and Throat Diseases, Head and Neck Surgery, Greifswald, Germany
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Ihler F, Freytag S, Kloos B, Spiegel JL, Haubner F, Canis M, Weiss BG, Bertlich M. Lipopolysaccharide decreases cochlear blood flow dose dependently in a guinea pig animal model via TNF signaling. Microcirculation 2021; 28:e12681. [PMID: 33501679 DOI: 10.1111/micc.12681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the effect of Lipopolysaccharide (LPS), a bacterial endotoxin on cochlear microcirculation, and its mode of action. METHODS Twenty-five Dunkin-Hartley guinea pigs were divided into five groups of five animals each. After surgical preparation, cochlear microcirculation was quantified by in vivo fluorescence microscopy. Placebo or LPS (1 mg, 10 µg, and 100 ng) was applied topically, and microcirculation was measured before and twice after application. A fifth group was pretreated with etanercept, a tumor necrosis factor (TNF) antagonist, and afterward the lowest LPS concentrations that yielded significant results (10 µg) were applied. RESULTS In the groups that had been treated with 1 mg and 10 µg LPS, a significant drop in cochlear microcirculation was observed after 30 (.791 ± .089 Arbitrary Units (AU), compared to baseline, and .888 ± .071AU) and 60 (.756 ± .101 AU and .817 ± .124 AU, respectively) minutes. The groups that had been treated with 100 ng LPS and that had been pretreated with etanercept showed no significant change in cochlear blood flow compared to placebo. CONCLUSION Lipopolysaccharide shows a dose-dependent effect on cochlear microcirculation; this effect can already be observed after 30 min. Pretreatment with etanercept can abrogate this effect, indicating that TNF mediates the effect of LPS on cochlear microcirculation.
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Affiliation(s)
- Friedrich Ihler
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Saskia Freytag
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Benedikt Kloos
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Jennifer Lee Spiegel
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Frank Haubner
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Martin Canis
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Bernhard G Weiss
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Mattis Bertlich
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
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Katsumi S, Sahin MI, Lewis RM, Iyer JS, Landegger LD, Stankovic KM. Intracochlear Perfusion of Tumor Necrosis Factor-Alpha Induces Sensorineural Hearing Loss and Synaptic Degeneration in Guinea Pigs. Front Neurol 2020; 10:1353. [PMID: 32116980 PMCID: PMC7025643 DOI: 10.3389/fneur.2019.01353] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/09/2019] [Indexed: 12/15/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-α) is a proinflammatory cytokine that plays a prominent role in the nervous system, mediating a range of physiologic and pathologic functions. In the auditory system, elevated levels of TNF-α have been implicated in several types of sensorineural hearing loss, including sensorineural hearing loss induced by vestibular schwannoma, a potentially fatal intracranial tumor that originates from the eighth cranial nerve; however, the mechanisms underlying the tumor's deleterious effects on hearing are not well-understood. Here, we investigated the effect of acute elevations of TNF-α in the inner ear on cochlear function and morphology by perfusing the cochlea with TNF-α in vivo in guinea pigs. TNF-α perfusion did not significantly change thresholds for compound action potential (CAP) responses, which reflect cochlear nerve activity, or distortion product otoacoustic emissions, which reflect outer hair cell integrity. However, intracochlear TNF-α perfusion reduced CAP amplitudes and increased the number of inner hair cell synapses without paired post-synaptic terminals, suggesting a pattern of synaptic degeneration that resembles that observed in primary cochlear neuropathy. Additionally, etanercept, a TNF-α blocker, protected against TNF-α-induced synaptopathy when administered systemically prior to intracochlear TNF-α perfusion. Findings motivate further investigation into the harmful effects of chronically elevated intracochlear levels of TNF-α, and the potential for etanercept to counter these effects.
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Affiliation(s)
- Sachiyo Katsumi
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Mehmet I Sahin
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Rebecca M Lewis
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Janani S Iyer
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, United States
| | - Lukas D Landegger
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA, United States.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, United States.,Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, MA, United States.,Harvard Program in Therapeutic Science, Harvard Medical School, Boston, MA, United States
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Evidence Supporting the Hypothesis That Inflammation-Induced Vasospasm Is Involved in the Pathogenesis of Acquired Sensorineural Hearing Loss. Int J Otolaryngol 2019; 2019:4367240. [PMID: 31781229 PMCID: PMC6875011 DOI: 10.1155/2019/4367240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/04/2019] [Accepted: 10/19/2019] [Indexed: 12/15/2022] Open
Abstract
Sensorineural hearing loss is mainly acquired and affects an estimated 1.3 billion humans worldwide. It is related to aging, noise, infection, ototoxic drugs, and genetic defects. It is essential to identify reversible and preventable causes to be able to reduce the burden of this disease. Inflammation is involved in most causes and leads to tissue injury through vasospasm-associated ischemia. Vasospasm is reversible. This review summarized evidence linking inflammation-induced vasospasm to several forms of acquired sensorineural hearing loss. The link between vasospasm and sensorineural hearing loss is directly evident in subarachnoid haemorrhage, which involves the release of vasoconstriction-inducing cytokines like interleukin-1, endothelin-1, and tumour necrosis factor. These proinflammatory cytokines can also be released in response to infection, autoimmune disease, and acute or chronically increased inflammation in the ageing organism as in presbyacusis or in noise-induced cochlear injury. Evidence of vasospasm and hearing loss has also been discovered in bacterial meningitis and brain injury. Resolution of inflammation-induced vasospasm has been associated with improvement of hearing in autoimmune diseases involving overproduction of interleukin-1 from inflammasomes. There is mainly indirect evidence for vasospasm-associated sensorineural hearing loss in most forms of systemic or injury- or infection-induced local vascular inflammation. This opens up avenues in prevention and treatment of vascular and systemic inflammation as well as vasospasm itself as a way to prevent and treat most forms of acquired sensorineural hearing loss. Future research needs to investigate interventions antagonising vasospasm and vasospasm-inducing proinflammatory cytokines and their production in randomised controlled trials of prevention and treatment of acquired sensorineural hearing loss. Prime candidates for interventions are hereby inflammasome inhibitors and vasospasm-reducing drugs like nitric oxide donors, rho-kinase inhibitors, and magnesium which have the potential to reduce sensorineural hearing loss in meningitis, exposure to noise, brain injury, arteriosclerosis, and advanced age-related and autoimmune disease-related inflammation.
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Abstract
According to a recent epidemiological survey, the incidence of sudden sensorineural hearing loss (SSNHL) is increasing yearly. The cause of SSNHL is of great interest in research. To date, viral infection, vascular occlusion, abnormal cellular stress responses within the cochlea, and immune-mediated mechanisms are considered the most likely etiologies of this disease. Among these etiologies, the relationship between viral infection and sudden deafness has been unclear. In this review, we mainly discuss the viral hypothesis of SSNHL. There is little research proving or clearly indicating the pathogenesis of this disease. Further research is needed to elucidate the precise etiopathogenesis to better understand SSNHL and establish more suitable treatment to help restore hearing in affected patients.
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Affiliation(s)
- Xin Chen
- 1 ENT institute, Eye & ENT Hospital of Fudan University, Shanghai, China
| | - Yao-Yao Fu
- 1 ENT institute, Eye & ENT Hospital of Fudan University, Shanghai, China
| | - Tian-Yu Zhang
- 2 ENT institute, Eye & ENT Hospital of Fudan University, Shanghai, China; Hearing Medicine Key Laboratory, National Health and Family Planning Commission, Shanghai, China
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Inflammatory cytokines and mononuclear cells in sudden sensorineural hearing loss. The Journal of Laryngology & Otology 2019; 133:95-101. [PMID: 30739608 DOI: 10.1017/s0022215119000100] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE This study evaluated tumour necrosis factor-α, interleukins 10 and 12, and interferon-γ levels, peripheral blood mononuclear cells, and clusters of differentiation 17c and 86 expression in unilateral sudden sensorineural hearing loss. METHODS Twenty-four patients with unilateral sudden sensorineural hearing loss, and 24 individuals with normal hearing and no history of sudden sensorineural hearing loss (who were attending the clinic for other problems), were enrolled. Peripheral blood mononuclear cells, and clusters of differentiation 11c and 86 were isolated and analysed. Plasma and supernatant levels of tumour necrosis factor-α, interferon-γ, and interleukins 10 and 12 were measured. RESULTS There were no significant differences with respect to age and gender. Monocyte population, mean tumour necrosis factor-α level and cluster of differentiation 86 expression were significantly increased in the study group compared to the control group. However, interferon-γ and interleukin 12 levels were significantly decreased. The difference in mean interleukin 10 level was not significant. CONCLUSION Increases in tumour necrosis factor-α level and monocyte population might play critical roles in sudden sensorineural hearing loss. This warrants detailed investigation and further studies on the role of dendritic cells in sudden sensorineural hearing loss.
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Canis M, Bertlich M. Cochlear Capillary Pericytes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1122:115-123. [PMID: 30937866 DOI: 10.1007/978-3-030-11093-2_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Capillary pericytes in the cochlea of mammals are-compared to pericytes in other tissues, like the CNS-relatively poorly researched. To begin with, there is still a considerable debate as to whether the very last precapillary arterioles should-due to their contractile properties-may be considered to be pericytes.However, cochlear capillary pericytes have shifted into the center of attention in the past decade. Most mammals show a considerable number of pericytes in the stria vascularis of the cochlea-up to 1300 in a mouse alone. This high number may be explained by the observation that cochlear capillary pericytes may be differentiated into different subgroups, depending on the immune markers that are expressed by them. Corresponding with these subpopulations, cochlear pericytes fulfill three core functions in the physiology of the cochlea: Formation of the intrastrial blood-fluid barrier-Pericytes monitor the ion, fluid, and nutrient household and aid in the homeostasis thereof. Regulation of cochlear blood flow-By contraction on relaxation, pericytes contribute to the regulation of cochlear blood flow, a paramount function parameter of the cochlea. Immune response-Pericytes actually contribute to the immune response in inflammation of the cochlea. Due to these central roles in the physiology of the cochlea, pericytes actually play a major role in numerous cochlear pathologies, including, but not limited to, sudden sensorineural hearing loss, acoustic trauma, and inflammation of the cochlea.
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Affiliation(s)
- Martin Canis
- The Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Munich, Germany
| | - Mattis Bertlich
- The Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Munich, Germany.
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Bertlich M, Ihler F, Weiss BG, Freytag S, Strupp M, Canis M. Cochlear Pericytes Are Capable of Reversibly Decreasing Capillary Diameter In Vivo After Tumor Necrosis Factor Exposure. Otol Neurotol 2018; 38:e545-e550. [PMID: 29135875 DOI: 10.1097/mao.0000000000001523] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE The aim of this work was to evaluate the effect of tumor necrosis factor (TNF) and its neutralization with etanercept on the capability of cochlear pericytes to alter capillary diameter in the stria vascularis. METHODS Twelve Dunkin-Hartley guinea pigs were randomly assigned to one of three groups. Each group was treated either with placebo and then placebo, TNF and then placebo, or TNF and then etanercept. Cochlear pericytes were visualized using diaminofluorescein-2-diacetate and intravasal blood flow by fluorescein-dextrane. Vessel diameter at sites of pericyte somas and downstream controls were quantified by specialized software. Values were obtained before treatment, after first treatment with tumor necrosis factor or placebo and after second treatment with etanercept or placebo. RESULTS Overall, 199 pericytes in 12 animals were visualized. After initial treatment with TNF, a significant decrease in vessel diameter at sites of pericyte somas (3.6 ±4.3%, n = 141) compared with placebo and downstream controls was observed. After initial treatment with TNF, the application of etanercept caused a significant increase (3.3 ±5.5%, n = 59) in vessel diameter at the sites of pericyte somata compared with placebo and downstream controls. CONCLUSION We have been able to show that cochlear pericytes are capable of reducing capillary diameter after exposition to TNF. Moreover, the reduction in capillary diameter observed after the application of TNF is revertible after neutralization of tumor necrosis factor by the application of etanercept. It seems that contraction of cochlear pericytes contributes to the regulation of cochlear blood flow.
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Affiliation(s)
- Mattis Bertlich
- *Department of Otorhinolaryngology-Head and Neck Surgery, University Medical Center Göttingen, Göttingen, Germany †Population Health and Immunity Division, Walter and Eliza Hall Institute ‡Department of Medical Biology, University of Melbourne, Parkville, Australia §Department of Neurology, Munich University Hospital, Munich, Germany
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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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Bertlich M, Ihler F, Weiss BG, Freytag S, Strupp M, Jakob M, Canis M. Role of capillary pericytes and precapillary arterioles in the vascular mechanism of betahistine in a guinea pig inner ear model. Life Sci 2017; 187:17-21. [DOI: 10.1016/j.lfs.2017.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/03/2017] [Accepted: 08/14/2017] [Indexed: 10/19/2022]
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Fingolimod (FTY-720) is Capable of Reversing Tumor Necrosis Factor Induced Decreases in Cochlear Blood Flow. Otol Neurotol 2017; 38:1213-1216. [DOI: 10.1097/mao.0000000000001510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tumor Necrosis Factor-induced Decrease of Cochlear Blood Flow Can Be Reversed by Etanercept or JTE-013. Otol Neurotol 2017; 37:e203-8. [PMID: 27295443 DOI: 10.1097/mao.0000000000001095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HYPOTHESIS This study aimed to quantify the effects of tumor necrosis factor (TNF) inhibitor Etanercept and sphingosine-1-phosphate receptor 2 antagonist JTE-013 on cochlear blood flow in guinea pigs after TNF-induced decrease. BACKGROUND Sudden sensorineural hearing loss is a common cause for disability and reduced quality of life. Good understanding of the pathophysiology and strong evidence-based therapy concepts are still missing. In various inner ear disorders, inflammation and impairment of cochlear blood flow (CBF) have been considered factors in the pathophysiology. A central mediator of inflammation and microcirculation in the cochlea is TNF. S1P acts downstream in one TNF pathway. METHODS Cochlea lateral wall vessels were exposed surgically and assessed by intravital microscopy in guinea pigs in vivo. Twenty-eight animals were randomly distributed into four groups of seven each. Exposed vessels were superfused by TNF (5.0 ng/ml) and afterward repeatedly either by Etanercept (1.0 μg/ml), JTE-013 (10 μmol/L), or vehicle (0.9 % NaCl solution or ethanol: phosphate-buffered saline buffer, respectively). RESULTS After decreasing CBF with TNF (p <0.001, two-way RM ANOVA), both treatments reversed CBF, compared with vehicle (p <0.001, two-way RM ANOVA). The comparison of the vehicle groups showed no difference (p = 0.969, two-way RM ANOVA), while there was also no difference between the treatment groups (p = 0.850, two-way RM ANOVA). CONCLUSION Both Etanercept and JTE-013 reverse the decreasing effect of TNF on cochlear blood flow and, therefore, TNF and the S1P-signalling pathway might be targets for treatment of microcirculation-related hearing loss.
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Drug-induced Defibrinogenation as New Treatment Approach of Acute Hearing Loss in an Animal Model for Inner Ear Vascular Impairment. Otol Neurotol 2017; 38:648-654. [DOI: 10.1097/mao.0000000000001400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
HYPOTHESIS Gene expression changes occur in conjunction with hearing threshold changes after cochlear implantation. BACKGROUND Between 30 and 50% of individuals who receive electro-acoustic stimulation (EAS) cochlear implants lose residual hearing after cochlear implantation, reducing the benefits of EAS. The mechanism underlying this hearing loss is unknown; potential pathways include mechanical damage, inflammation, or tissue remodeling changes. METHODS Guinea pigs were implanted in one ear with cochlear implant electrode arrays, with non-implanted ears serving as controls, and allowed to recover for 1, 3, 7, or 14 days. Hearing threshold changes were measured over time. Cochlear ribonucleic acid was analyzed using real-time quantitative reverse transcription-polymerase chain reaction from the following gene families: cytokines, tight junction claudins, ion and water (aquaporin) transport channels, gap junction connexins, and tissue remodeling genes. RESULTS Significant increases in expression were observed for cochlear inflammatory genes (Cxcl1, IL-1β, TNF-α, and Tnfrsf1a/b) and ion homeostasis genes (Scnn1γ, Aqp3, and Gjb3). Upregulation of tissue remodeling genes (TGF-β, MMP2, MMP9) as well as a paracrine gene (CTGF) was also observed. Hearing loss occurred rapidly, peaking at 3 days with some recovery at 7 and 14 days after implantation. MM9 exhibited extreme upregulation of expression and was qualitatively associated with changes in hearing thresholds. CONCLUSION Cochlear implantation induces similar changes as middle ear inflammation for genes involved in inflammation and ion and water transport function, whereas tissue remodeling changes differ markedly. The upregulation of MMP9 with hearing loss is consistent with previous findings linking stria vascularis vessel changes with cochlear implant-induced hearing loss.
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Ihler F, Pelz S, Coors M, Matthias C, Canis M. Application of a TNF-alpha-inhibitor into the scala tympany after cochlear electrode insertion trauma in guinea pigs: preliminary audiologic results. Int J Audiol 2015; 53:810-6. [PMID: 25311100 DOI: 10.3109/14992027.2014.938369] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Cochlear implantation trauma causes both macroscopic and inflammatory trauma. The aim of the present study was to evaluate the effectiveness of the TNF-alpha inhibitor etanercept applied after cochlear implantation trauma on the preservation of acoustic hearing. DESIGN Guinea pigs were randomly assigned to three groups receiving cochlear implantation trauma by cochleostomy. In one group, the site was sealed by bone cement with no further treatment. A second group was additionally implanted with an osmotic minipump delivering artificial perilymph into the scala tympani for seven days. In the third group, etanercept 1 mg/ml was added to artificial perilymph. Hearing was assessed by auditory brainstem responses at 2, 4, 6, and 8 kHz prior to and after surgery and on days 3, 5, 7, 14, 28. STUDY SAMPLE Fifteen healthy guinea pigs. RESULTS The trauma led to threshold shifts from 50.3 dB ± 16.3 dB to 68.0 dB ± 19.3 dB. Hearing thresholds were significantly lower in etanercept-treated animals compared to controls on day 28 at 8 kHz and from day 3 onwards at 4 and 2 kHz (p < 0.01; two-way RM ANOVA / Bonferroni t-test). CONCLUSION The application of etanercept led to preservation of acoustic hearing after cochlear implantation trauma.
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Affiliation(s)
- Friedrich Ihler
- * Department of Otorhinolaryngology, University Medical Center Göttingen , Germany
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Two-photon microscopy allows imaging and characterization of cochlear microvasculature in vivo. BIOMED RESEARCH INTERNATIONAL 2015; 2015:154272. [PMID: 25883941 PMCID: PMC4390612 DOI: 10.1155/2015/154272] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 11/18/2022]
Abstract
Impairment of cochlear blood flow has been discussed as factor in the pathophysiology of various inner ear disorders. However, the microscopic study of cochlear microcirculation is limited due to small scale and anatomical constraints. Here, two-photon fluorescence microscopy is applied to visualize cochlear microvessels. Guinea pigs were injected with Fluorescein isothiocyanate- or Texas red-dextrane as plasma marker. Intravital microscopy was performed in four animals and explanted cochleae from four animals were studied. The vascular architecture of the cochlea was visualized up to a depth of 90.0±22.7 μm. Imaging yielded a mean contrast-to-noise ratio (CNR) of 3.3±1.7. Mean diameter in vivo was 16.5±6.0 μm for arterioles and 8.0±2.4 μm for capillaries. In explanted cochleae, the diameter of radiating arterioles and capillaries was measured with 12.2±1.6 μm and 6.6±1.0 μm, respectively. The difference between capillaries and arterioles was statistically significant in both experimental setups (P<0.001 and P=0.022, two-way ANOVA). Measured vessel diameters in vivo and ex vivo were in agreement with published data. We conclude that two-photon fluorescence microscopy allows the investigation of cochlear microvessels and is potentially a valuable tool for inner ear research.
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Toktas H, Okur E, Dundar U, Dikici A, Kahveci OK. Infliximab has no apparent effect in the inner ear hearing function of patients with rheumatoid arthritis and ankylosing spondylitis. Clin Rheumatol 2014; 33:1481-7. [PMID: 24770796 DOI: 10.1007/s10067-014-2625-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 03/07/2014] [Accepted: 04/10/2014] [Indexed: 12/01/2022]
Abstract
Animal studies suggest that tumor necrosis factor (TNF) alpha blockers may pass to the inner ear in adequate concentration. In this prospective study, we aimed to evaluate the effect of infliximab on the inner ear hearing function in patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA). The patients with high disease activity, who were planned to begin infliximab for therapy by physical medicine and rehabilitation department, were referred to ear-nose-throat clinic for consultation. After physical and otoscopic examination, audiological tests were performed. Air conduction thresholds between 250 and 8,000 Hz, bone conduction thresholds between 500 and 4,000 Hz, pure tone average, speech discrimination scores, distortion product otoacoustic emission (DPOAE) were used to evaluate the hearing function. The tests were repeated 2 and 6 months after the initiation of the drug "infliximab." A total of 44 ears of 22 patients (17 males and 5 females) were evaluated. Fifteen patients had a diagnosis of AS, and seven patients had RA. After initiation of infliximab therapy, statistically significant improvement was observed in disease activity scores [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for AS, Disease Activity Score 28 (DAS-28) for RA] after 2 and 6 months (p < 0.05). We did not find any statistically significant difference between the air conduction thresholds, bone conduction thresholds, pure tone average, speech discrimination scores, and measurements of DPOAE before the initiation of treatment and after 2 and 6 months (p > 0.05). Any problem about the balance, vertigo, or dizziness was not reported from the patients during the treatment period. As a result, our study showed that there was no notable change or deterioration in the hearing function of the patients with AS and RA who were treated with infliximab. Further studies with higher number of patients with AS and RA and also with different TNF alpha inhibitors are needed to make more valid conclusion.
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Affiliation(s)
- H Toktas
- Faculty of Medicine, Department of Physical Medicine and Rehabilitation, Afyon Kocatepe University, 03200, Afyonkarahisar, Turkey
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