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Pan J, Wang K, Qu J, Chen D, Chen A, You Y, Tang J, Zhang H. Activated tissue-resident macrophages contribute to hair cell insults in noise-induced hearing loss in mice. Commun Biol 2024; 7:1078. [PMID: 39223249 DOI: 10.1038/s42003-024-06768-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Abstract
Macrophages serve as the primary immune cell population and assume a pivotal role in the immune response within the damaged cochleae. Yet, the origin and role of macrophages in response to noise exposure remain controversial. Here, we take advantage of Ccr2RFP/+ Cx3cr1GFP/+ dual-reporter mice to identify the infiltrated and tissue-resident macrophages. After noise exposure, we reveal that activated resident macrophages change in morphology, increase in abundance, and migrate to the region of hair cells, leading to the loss of outer hair cells and the damage of ribbon synapses. Meanwhile, peripheral monocytes are not implicated in the noise-induced hair cell insults. These noise-induced activities of macrophages are abolished by inhibiting TLR4 signaling, resulting in alleviated insults of hair cells and partial recovery of hearing. Our findings indicate cochlear resident macrophages are pro-inflammatory and detrimental players in acoustic trauma and introduce a potential therapeutic target in noise-induced hearing loss.
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Affiliation(s)
- Jing Pan
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Kaiye Wang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Jiaxi Qu
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Dongxiu Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Anning Chen
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Yunyou You
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Jie Tang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
- Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou, 510515, China.
- Guangdong-Hong Kong Joint Laboratory for Psychiatric Disorders, Southern Medical University, Guangzhou, 510515, China.
| | - Hongzheng Zhang
- Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
- Ear Research Institute, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China.
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2
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Maniaci A, La Via L, Lechien JR, Sangiorgio G, Iannella G, Magliulo G, Pace A, Mat Q, Lavalle S, Lentini M. Hearing Loss and Oxidative Stress: A Comprehensive Review. Antioxidants (Basel) 2024; 13:842. [PMID: 39061910 PMCID: PMC11274311 DOI: 10.3390/antiox13070842] [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: 06/11/2024] [Revised: 07/05/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
Hearing loss is a prevalent condition affecting millions of people worldwide. Hearing loss has been linked to oxidative stress as a major factor in its onset and progression. The goal of this thorough analysis is to investigate the connection between oxidative stress and hearing loss, with an emphasis on the underlying mechanisms and possible treatments. The review addressed the many forms of hearing loss, the role of reactive oxygen species (ROS) in causing damage to the cochlea, and the auditory system's antioxidant defensive mechanisms. The review also goes over the available data that support the use of antioxidants and other methods to lessen hearing loss brought on by oxidative stress. We found that oxidative stress is implicated in multiple types of hearing loss, including age-related, noise-induced, and ototoxic hearing impairment. The cochlea's unique anatomical and physiological characteristics, such as high metabolic activity and limited blood supply, make it particularly susceptible to oxidative damage. Antioxidant therapies have shown promising results in both animal models and clinical studies for preventing and mitigating hearing loss. Emerging therapeutic approaches, including targeted drug delivery systems and gene therapy, offer new possibilities for addressing oxidative stress in the auditory system. The significance of this review lies in its comprehensive analysis of the intricate relationship between oxidative stress and hearing loss. By synthesizing current knowledge and identifying gaps in understanding, this review provides valuable insights for both researchers and clinicians. It highlights the potential of antioxidant-based interventions and emphasizes the need for further research into personalized treatment strategies. Our findings on oxidative stress mechanisms may also affect clinical practice and future research directions. This review serves as a foundation for developing novel therapeutic approaches and may inform evidence-based strategies for the prevention and treatment of hearing loss, ultimately contributing to improved quality of life for millions affected by this condition worldwide.
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Affiliation(s)
- A. Maniaci
- Faculty of Medicine and Surgery, University of Enna Kore, 94100 Enna, Italy;
- ASP Ragusa-Hospital Giovanni Paolo II, 97100 Ragusa, Italy;
- Otology Study Group, Young Otolaryngologists-International Federation of Otorhinolaryngological Societies, 13005 Paris, France; (J.R.L.); (G.I.); (A.P.); (Q.M.)
| | - L. La Via
- Department of Anaesthesia and Intensive Care, University Hospital Policlinico-San Marco, 95125 Catania, Italy
| | - J. R. Lechien
- Otology Study Group, Young Otolaryngologists-International Federation of Otorhinolaryngological Societies, 13005 Paris, France; (J.R.L.); (G.I.); (A.P.); (Q.M.)
- Department of Human Anatomy and Experimental Oncology, Faculty of Medicine, UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), 7000 Mons, Belgium
- Department of Otolaryngology-Head & Neck Surgery, Foch Hospital, School of Medicine, UFR Simone Veil, Université Versailles Saint-Quentin-en-Yvelines (Paris Saclay University), 78180 Paris, France
- Department of Otolaryngology-Head & Neck Surgery, EpiCURA Hospital, 7301 Hornu, Belgium
| | - G. Sangiorgio
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy;
| | - G. Iannella
- Otology Study Group, Young Otolaryngologists-International Federation of Otorhinolaryngological Societies, 13005 Paris, France; (J.R.L.); (G.I.); (A.P.); (Q.M.)
- Department of ‘Organi di Senso’, University “Sapienza”, 00185 Rome, Italy;
| | - G. Magliulo
- Department of ‘Organi di Senso’, University “Sapienza”, 00185 Rome, Italy;
| | - A. Pace
- Otology Study Group, Young Otolaryngologists-International Federation of Otorhinolaryngological Societies, 13005 Paris, France; (J.R.L.); (G.I.); (A.P.); (Q.M.)
- Department of ‘Organi di Senso’, University “Sapienza”, 00185 Rome, Italy;
| | - Q. Mat
- Otology Study Group, Young Otolaryngologists-International Federation of Otorhinolaryngological Societies, 13005 Paris, France; (J.R.L.); (G.I.); (A.P.); (Q.M.)
- Department of Otorhinolaryngology, C.H.U. Charleroi, Chaussée de Bruxelles 140, 6042 Charleroi, Belgium
| | - S. Lavalle
- Faculty of Medicine and Surgery, University of Enna Kore, 94100 Enna, Italy;
| | - M. Lentini
- ASP Ragusa-Hospital Giovanni Paolo II, 97100 Ragusa, Italy;
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3
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Lou J, He W, Cui B, Wu F, Liu W, Deng J, Huang Y, Zhang Z, Si Y. Gram-negative Bacteria are Associated With Sensorineural Hearing Loss in Chronic Otitis Media. Laryngoscope 2024; 134:3335-3341. [PMID: 38332523 DOI: 10.1002/lary.31322] [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: 07/31/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 02/10/2024]
Abstract
OBJECT Chronic otitis media (COM) is an inflammatory disease that commonly presents with otorrhea and hearing loss. Bacteria-induced inflammation can cause inner ear damage, leading to sensorineural hearing loss (SNHL). This study aimed to compare the prevalence and severity of SNHL in patients with gram-negative versus gram-positive cultures and examine associations between the concentrations of circulating monocytes and neutrophils with bacteria species and SNHL. METHODS This was a retrospective study. Cholesteatoma or chronic suppurative otitis media patients with otorrhea were enrolled. Middle ear secretions were collected using sterile swabs under an otoscope, and sent for bacterial detection within 30 min. Pure tone audiometry and circulating leukocyte counts were recorded and analyzed in patients infected with different pathogens. Logistic regression analysis was used to identify the risk factors associated with SNHL. RESULTS A total of 137 patients were enrolled, including 45 patients infected with gram-negative bacteria, 41 with gram-positive bacteria, 20 with polymicrobial infection, and 31 with no bacterial growth. Logistic regression analysis showed that bacterial culture positive infections (OR = 7.265, 95% CI 2.219-23.786, p = 0.001) were an independent risk factor for SNHL. Patients with gram-negative bacteria had higher risks of SNHL (p < 0.0001) and more severe hearing loss (p = 0.005) than those with gram-positive bacteria. COM patients infected with gram-negative bacteria showed an increase in circulating monocytes, which correlated with the occurrence of SNHL (p = 0.0343). CONCLUSION Gram-negative bacteria are associated with elevated circulating monocyte counts and have a higher risk of severe SNHL. LEVEL OF EVIDENCE 4 Laryngoscope, 134:3335-3341, 2024.
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Affiliation(s)
- Jintao Lou
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Wuhui He
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Bozhen Cui
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Fan Wu
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Wei Liu
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Jingman Deng
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Yan Huang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Zhigang Zhang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
| | - Yu Si
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
- Institute of Hearing and Speech-Language Science, Sun Yat-sen University, Guangzhou, China
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Typiak M, Żurawa-Janicka D. Not an immune cell, but they may act like one-cells with immune properties outside the immune system. Immunol Cell Biol 2024; 102:487-499. [PMID: 38650437 DOI: 10.1111/imcb.12752] [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: 01/09/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
The cells presented in this work are not classified as cells that make up the immune system. They, however, present functions and molecules, which are characteristic of immune cells. These characteristic functions are, for example, sensing threat, performing phagocytosis, presentation of foreign antigens, cytokine release or enhancing immune memory. The enlisted immune response mechanisms are carried out by the possession of molecules such as Toll-like receptors, receptors for the Fc fragment of IgG, major histocompatibility complex class II molecules, costimulatory CD80/CD86 proteins and molecules needed for NLRP3 (NOD-like family pyrin domain containing 3) inflammasome activation. Thanks to these properties, the described nonimmune cells play an important role in the local immune response and support of the entire body in the fight against pathogens. They constitute the first line of defense of tissues and organs against pathogens and molecules recognized as harmful. The cells described in this article are particularly important in immunologically privileged places (e.g. the Bowman's capsule in the kidney), where "typical" immune cells normally do not have access. In this paper, we present immune-like functions and molecule suites of resident kidney cells (podocytes and mesangial cells), cochlear resident cells, fibrocytes and fibroblasts, as well as some stem cells (mesenchymal stem cells and umbilical cord Wharton's jelly-derived cells).
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Affiliation(s)
- Marlena Typiak
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
| | - Dorota Żurawa-Janicka
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308, Gdansk, Poland
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Liu W, Li H, Kämpfe Nordström C, Danckwardt-Lillieström N, Agrawal S, Ladak HM, Rask-Andersen H. Immuno-surveillance and protection of the human cochlea. Front Neurol 2024; 15:1355785. [PMID: 38817543 PMCID: PMC11137295 DOI: 10.3389/fneur.2024.1355785] [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: 12/14/2023] [Accepted: 02/21/2024] [Indexed: 06/01/2024] Open
Abstract
Background Despite its location near infection-prone areas, the human inner ear demonstrates remarkable resilience. This suggests that there are inherent instruments deterring the invasion and spread of pathogens into the inner ear. Here, we combined high-resolution light microscopy, super-resolution immunohistochemistry (SR-SIM) and synchrotron phase contrast imaging (SR-PCI) to identify the protection and barrier systems in the various parts of the human inner ear, focusing on the lateral wall, spiral ganglion, and endolymphatic sac. Materials and methods Light microscopy was conducted on mid-modiolar, semi-thin sections, after direct glutaraldehyde/osmium tetroxide fixation. The tonotopic locations were estimated using SR-PCI and 3D reconstruction in cadaveric specimens. The sections were analyzed for leucocyte and macrophage activity, and the results were correlated with immunohistochemistry using confocal microscopy and SR-SIM. Results Light microscopy revealed unprecedented preservation of cell anatomy and several macrophage-like cells that were localized in the cochlea. Immunohistochemistry demonstrated IBA1 cells frequently co-expressing MHC II in the spiral ganglion, nerve fibers, lateral wall, spiral limbus, and tympanic covering layer at all cochlear turns as well as in the endolymphatic sac. RNAscope assays revealed extensive expression of fractalkine gene transcripts in type I spiral ganglion cells. CD4 and CD8 cells occasionally surrounded blood vessels in the modiolus and lateral wall. TMEM119 and P2Y12 were not expressed, indicating that the cells labeled with IBA1 were not microglia. The round window niche, compact basilar membrane, and secondary spiral lamina may form protective shields in the cochlear base. Discussion The results suggest that the human cochlea is surveilled by dwelling and circulating immune cells. Resident and blood-borne macrophages may initiate protective immune responses via chemokine signaling in the lateral wall, spiral lamina, and spiral ganglion at different frequency locations. Synchrotron imaging revealed intriguing protective barriers in the base of the cochlea. The role of the endolymphatic sac in human inner ear innate and adaptive immunity is discussed.
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Affiliation(s)
- Wei Liu
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Hao Li
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Charlotta Kämpfe Nordström
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | | | - Sumit Agrawal
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
- Department of Electrical and Computer Engineering, Western University, London, ON, Canada
| | - Hanif M. Ladak
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
- Department of Electrical and Computer Engineering, Western University, London, ON, Canada
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
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Bovee S, Klump GM, Köppl C, Pyott SJ. The Stria Vascularis: Renewed Attention on a Key Player in Age-Related Hearing Loss. Int J Mol Sci 2024; 25:5391. [PMID: 38791427 PMCID: PMC11121695 DOI: 10.3390/ijms25105391] [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: 04/13/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related hearing loss (HL), or presbycusis, is a complex and heterogeneous condition, affecting a significant portion of older adults and involving various interacting mechanisms. Metabolic presbycusis, a type of age-related HL, is characterized by the dysfunction of the stria vascularis, which is crucial for maintaining the endocochlear potential necessary for hearing. Although attention on metabolic presbycusis has waned in recent years, research continues to identify strial pathology as a key factor in age-related HL. This narrative review integrates past and recent research, bridging findings from animal models and human studies, to examine the contributions of the stria vascularis to age-related HL. It provides a brief overview of the structure and function of the stria vascularis and then examines mechanisms contributing to age-related strial dysfunction, including altered ion transport, changes in pigmentation, inflammatory responses, and vascular atrophy. Importantly, this review outlines the contribution of metabolic mechanisms to age-related HL, highlighting areas for future research. It emphasizes the complex interdependence of metabolic and sensorineural mechanisms in the pathology of age-related HL and highlights the importance of animal models in understanding the underlying mechanisms. The comprehensive and mechanistic investigation of all factors contributing to age-related HL, including cochlear metabolic dysfunction, remains crucial to identifying the underlying mechanisms and developing personalized, protective, and restorative treatments.
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Affiliation(s)
- Sonny Bovee
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
| | - Georg M. Klump
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
- Cluster of Excellence “Hearing4all”, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Centre Neurosensory Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Christine Köppl
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
- Cluster of Excellence “Hearing4all”, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Centre Neurosensory Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Sonja J. Pyott
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
- The Research School of Behavioural and Cognitive Neurosciences, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
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Hayashi Y. Signaling pathways regulating the immune function of cochlear supporting cells and their involvement in cochlear pathophysiology. Glia 2024; 72:665-676. [PMID: 37933494 DOI: 10.1002/glia.24476] [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: 12/18/2022] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 11/08/2023]
Abstract
The inner ear, including the cochlea, used to be regarded as an immune-privileged site because of its immunologically isolated environment caused by the blood-labyrinthine barrier. Cochlear resident macrophages, which originate from the yolk sac or fetal liver during the embryonic stage and are maintained after birth, are distributed throughout various regions of the cochlear duct. Intriguingly, these cells are absent in the organ of Corti, where hair cells (HCs) and supporting cells (SCs) are located, except for a limited number of ionized calcium-binding adapter molecule 1 (Iba1)-positive cells. Instead, SCs exert glial functions varying from a quiescent to an emergency state. Notably, SCs acquire the nature of macrophages and begin to secrete inflammatory cytokines during viral infection in the organ of Corti, which is ostensibly unprotected owing to the lack of general resident macrophages. This review provides an overview of both positive and negative functions of SCs enabled to acquire macrophage phenotypes upon viral infection focusing on the signaling pathways that regulate these functions. The former function protects HCs from viral infection by inducting type I interferons, and the latter function induces HC death by necroptosis, leading to sensorineural hearing loss. Thus, SCs play contradictory roles as immune cells with acquired macrophage phenotypes; thereby, they are favorable and unfavorable to HCs, which play a pivotal role in hearing function.
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Affiliation(s)
- Yushi Hayashi
- Department of Molecular and Medical Genetics, Nippon Medical School, Tokyo, Japan
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8
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Liu YC, Xu K. Macrophage-related immune responses in inner ear: a potential therapeutic target for sensorineural hearing loss. Front Neurosci 2024; 17:1339134. [PMID: 38274500 PMCID: PMC10808290 DOI: 10.3389/fnins.2023.1339134] [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: 11/15/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024] Open
Abstract
Hearing loss is the most common sensory disorder in human beings. Cochlear sensory cells are the basis of hearing. Cochlear sensory cells suffer from various acute or chronic injuries, such as excessive sound stimulation, ototoxic drugs, and age-related degeneration. In response to these stresses, the cochlea develops an immune response. In recent years, studies have shown that the immune response of the inner ear has been regarded as one of the important pathological mechanisms of inner ear injury. Therapeutic interventions for inflammatory responses can effectively alleviate different types of inner ear injury. As the main immune cells in the inner ear, macrophages are involved in the process of inner ear injury caused by various exogenous factors. However, its specific role in the immune response of the inner ear is still unclear. This review focuses on discusses the dynamic changes of macrophages during different types of inner ear injury, and clarifies the potential role of macrophage-related immune response in inner ear injury.
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Affiliation(s)
- Yu-Chen Liu
- Queen Mary School, Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Kai Xu
- Department of Otolaryngology, Head and Neck Surgery, The Second Affiliated Hospital of Nanchang University, Jiangxi Medical College, Nanchang University, Nanchang, China
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9
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Miwa T, Rengasamy G, Liu Z, Ginhoux F, Okano T. Contribution of circulating monocytes in maintaining homeostasis of resident macrophages in postnatal and young adult mouse cochlea. Sci Rep 2024; 14:62. [PMID: 38167979 PMCID: PMC10762055 DOI: 10.1038/s41598-023-50634-y] [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: 09/01/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024] Open
Abstract
The percentage of macrophage subpopulations based on their origins in the adult cochlea remains unclear. This study aimed to elucidate the origins of cochlear macrophages during the onset phase and development of auditory function. We used three types of mice: wildtype ICR mice, colony-stimulating factor 1 receptor (Csf1r)-deficient mice, and Ms4a3Cre-Rosa tdTomato (Ms4a3tdT) transgenic mice. Macrophages were labeled with ionized calcium-binding adapter molecule 1 (Iba1), which is specific to more mature macrophages, and CD11b, which is specific to monocyte lineage. We investigated the spatial and temporal distribution patterns of resident macrophages in the cochlea during the postnatal and early adult stages. During the adult stages, the rate of monocytes recruited from the systemic circulation increased; moreover, Iba1+/CD11b- cochlear macrophages gradually decreased with age. Fate mapping of monocytes using Ms4a3tdT transgenic mice revealed an increased proportion of bone marrow-derived cochlear macrophages in the adult stage. Contrastingly, the proportion of yolk sac- and fetal liver-derived tissue-resident macrophages decreased steadily with age. This heterogeneity could be attributed to differences in environmental niches within the tissue or at the sub-tissue levels. Future studies should investigate the role of cochlear macrophages in homeostasis, inflammation, and other diseases, including infection, autoimmune, and metabolic diseases.
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Affiliation(s)
- Toru Miwa
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
- Department of Otolaryngology-Head and Neck Surgery, Osaka Metropolitan University, Abeno-ku, Osaka, Japan.
| | - Gowshika Rengasamy
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore, Singapore
| | - Zhaoyuan Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Florent Ginhoux
- Singapore Immunology Network, Agency for Science, Technology and Research, Singapore, Singapore
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- SingHealth Duke-NUS Academic Medical Centre, Translational Immunology Institute, Singapore, Singapore
- Institut Gustave Roussy, INSERM U1015, Villejuif, France
| | - Takayuki Okano
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
- Department of Otolaryngology-Head and Neck Surgery, Fujita Health University, Toyoake, Aichi, Japan
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10
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Zhang C, Ye M, Bush P, Hu BH. Heterogeneity in macrophages along the cochlear spiral in mice: insights from SEM and functional analyses. Front Cell Neurosci 2023; 17:1222074. [PMID: 37692550 PMCID: PMC10485373 DOI: 10.3389/fncel.2023.1222074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
The susceptibility of sensory cells to pathological conditions differs between the apical and basal regions of the cochlea, and the cochlear immune system may contribute to this location-dependent variability. Our previous study found morphological differences in basilar membrane macrophages between the apical and basal regions of the cochlea. However, the details of this site-dependent difference and its underlying structural and biological basis are not fully understood. In this study, we utilized scanning electron microscopy to examine the ultrastructure of macrophages and their surrounding supporting structures. Additionally, we examined the phagocytic activities of macrophages and the expression of immune molecules in both apical and basal regions of the cochlea. We employed two mouse strains (C57BL/6J and B6.129P-Cx3cr1tm1Litt/J) and evaluated three experimental conditions: young normal (1-4 months), aging (11-19 months), and noise-induced damage (120 dB SPL for 1 h). Using scanning electron microscopy, we revealed location-specific differences in basilar membrane macrophage morphology and surface texture, architecture in mesothelial cell layers, and spatial correlation between macrophages and mesothelial cells in both young and older mice. Observations of macrophage phagocytic activities demonstrated that basal macrophages exhibited greater phagocytic activities in aging and noise-damaged ears. Furthermore, we identified differences in the expression of immune molecules between the apical and basal cochlear tissues of young mice. Finally, our study demonstrated that as the cochlea ages, macrophages in the apical and basal regions undergo a transformation in their morphologies, with apical macrophages acquiring certain basal macrophage features and vice versa. Overall, our findings demonstrate apical and basal differences in macrophage phenotypes and functionality, which are related to distinct immune and structural differences in the macrophage surrounding tissues.
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Affiliation(s)
- Celia Zhang
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
- Department of Audiology, University of the Pacific, San Francisco, CA, United States
| | - Mengxiao Ye
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
| | - Peter Bush
- South Campus Instrument Center, University at Buffalo, Buffalo, NY, United States
| | - Bo Hua Hu
- Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY, United States
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11
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Hosoya M, Kitama T, Shimanuki MN, Nishiyama T, Oishi N, Okano H, Ozawa H. Distribution of macrophages in the developing cochlea of the common marmoset, a primate model animal. Front Immunol 2023; 14:1229414. [PMID: 37675123 PMCID: PMC10477578 DOI: 10.3389/fimmu.2023.1229414] [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: 05/26/2023] [Accepted: 08/04/2023] [Indexed: 09/08/2023] Open
Abstract
Introduction Macrophages are essential immune cells in the cochlea that contribute to inflammation, tissue repair, and homeostasis. They also play an important role in local cochlear immunity. The developmental immigration and maturation of macrophages in the cochlea have been investigated and are considered essential for normal hearing acquisition. Most of our current knowledge regarding cochlear development is based on rodent models because of the ethical challenges of using human fetal samples for research. However, inter-species differences between rodents and humans have been reported. In this study, we used a primate animal model to investigate the distributions of macrophages in the developing cochlea. The common marmoset (Callithrix jacchus), a small monkey species that inhabits the New World, was used as the model. Methods We investigated the distribution of macrophages in the developing cochlea of the common marmoset by performing immunohistochemical analyses of cochlear tissue from common marmoset embryos at different development stages. Results We revealed detailed distribution changes in the macrophages of a primate animal model cochlea. This observation indicates that most of the changes in the general distribution of macrophages were well preserved between rodents and this primate. The distribution changes observed in the common marmoset were also compatible with observations in the human fetus; although, observations in the human fetus are limited. Our observations in this study also revealed several differences between common marmosets and rodents. Conclusion The time course of immunological development and maturations established in this study will aid in the study of the primate-specific developmental biology of the inner ear. These observations may eventually lead to new therapeutic strategies for hearing loss in humans. In addition, understanding the immunological steady-state of the cochlea may help in the study of age- and genetic-induced hearing loss and in the design of regenerative therapies.
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Affiliation(s)
- Makoto Hosoya
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Tsubasa Kitama
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Marie N. Shimanuki
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Takanori Nishiyama
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Naoki Oishi
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Laboratory for Marmoset Neural Architecture, Center for Brain Science, RIKEN, Saitama, Japan
| | - Hiroyuki Ozawa
- Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine, Tokyo, Japan
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12
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Andrade da Silva LH, Heuer RA, Roque CB, McGuire TL, Hosoya T, Kimura H, Tamura K, Matsuoka AJ. Enhanced survival of hypoimmunogenic otic progenitors following intracochlear xenotransplantation: repercussions for stem cell therapy in hearing loss models. Stem Cell Res Ther 2023; 14:83. [PMID: 37046329 PMCID: PMC10099643 DOI: 10.1186/s13287-023-03304-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Stem cell replacement holds the potential for sensorineural hearing loss (SNHL) treatment. However, its translation into clinical practice requires strategies for improving stem cell survival following intracochlear transplantation. Considering recent findings showing that the inner ear contains a resident population of immune cells, we hypothesized that immune evasion would improve the survival and residence time of transplanted stem cells in the cochlea, potentially leading to better outcomes. To test this, we leveraged genetic engineering techniques to develop hypoimmunogenic human-induced pluripotent stem cells (hi-iPSC), which lack human leukocyte antigen expression. We found that gene editing does not affect the biological properties of hi-iPSCs, including their capacity to differentiate into otic neural progenitors (ONPs). Compared to wild-type ONPs, more hypoimmunogenic ONPs (derived from hi-iPSCs) were found in the inner ear of immunocompetent mice ten days following cochlear xenotransplantation. This approach may open a new avenue for experimental and clinical SNHL treatments.
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Affiliation(s)
- Luisa H Andrade da Silva
- Department of Otolaryngology and Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Rachel A Heuer
- Department of Otolaryngology and Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Christian B Roque
- Department of Otolaryngology and Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Tammy L McGuire
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | | | - Kouichi Tamura
- Kobe Research Institute, HEALIOS K.K., Kobe, Hyogo, Japan
| | - Akihiro J Matsuoka
- Department of Otolaryngology and Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Roxelyn and Richard Pepper Department of Communication Sciences and Disorders, School of Communication, Northwestern University, Evanston, IL, USA.
- Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Evanston, IL, USA.
- Center for Advanced Regenerative Engineering, Northwestern University, Evanston, IL, USA.
- Department of Otolaryngology and Head and Neck Surgery, University of California San Diego, 9444 Medical Center Drive, MC7895, La Jolla, CA, 92037, USA.
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13
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Al Aameri RFH, Alanisi EMA, Oluwatosin A, Al Sallami D, Sheth S, Alberts I, Patel S, Rybak LP, Ramkumar V. Targeting CXCL1 chemokine signaling for treating cisplatin ototoxicity. Front Immunol 2023; 14:1125948. [PMID: 37063917 PMCID: PMC10102581 DOI: 10.3389/fimmu.2023.1125948] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 03/17/2023] [Indexed: 04/03/2023] Open
Abstract
Cisplatin is chemotherapy used for solid tumor treatment like lung, bladder, head and neck, ovarian and testicular cancers. However, cisplatin-induced ototoxicity limits the utility of this agent in cancer patients, especially when dose escalations are needed. Ototoxicity is associated with cochlear cell death through DNA damage, the generation of reactive oxygen species (ROS) and the consequent activation of caspase, glutamate excitotoxicity, inflammation, apoptosis and/or necrosis. Previous studies have demonstrated a role of CXC chemokines in cisplatin ototoxicity. In this study, we investigated the role of CXCL1, a cytokine which increased in the serum and cochlea by 24 h following cisplatin administration. Adult male Wistar rats treated with cisplatin demonstrated significant hearing loss, assessed by auditory brainstem responses (ABRs), hair cell loss and loss of ribbon synapse. Immunohistochemical studies evaluated the levels of CXCL1 along with increased presence of CD68 and CD45-positive immune cells in cochlea. Increases in CXCL1 was time-dependent in the spiral ganglion neurons and organ of Corti and was associated with progressive increases in CD45, CD68 and IBA1-positive immune cells. Trans-tympanic administration of SB225002, a chemical inhibitor of CXCR2 (receptor target for CXCL1) reduced immune cell migration, protected against cisplatin-induced hearing loss and preserved hair cell integrity. We show that SB225002 reduced the expression of CXCL1, NOX3, iNOS, TNF-α, IL-6 and COX-2. Similarly, knockdown of CXCR2 by trans-tympanic administration of CXCR2 siRNA protected against hearing loss and loss of outer hair cells and reduced ribbon synapses. In addition, SB225002 reduced the expression of inflammatory mediators induced by cisplatin. These results implicate the CXCL1 chemokine as an early player in cisplatin ototoxicity, possibly by initiating the immune cascade, and indicate that CXCR2 is a relevant target for treating cisplatin ototoxicity.
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Affiliation(s)
- Raheem F. H. Al Aameri
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Entkhab M. A. Alanisi
- Department of Pharmaceutical Sciences, Larkin University College of Pharmacy, Miami, FL, United States
| | - Adu Oluwatosin
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Dheyaa Al Sallami
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Sandeep Sheth
- Department of Pharmaceutical Sciences, Larkin University College of Pharmacy, Miami, FL, United States
| | - Ian Alberts
- Medical Microbiology, Immunology and Cell Biology (MMICB), Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Shree Patel
- Medical Microbiology, Immunology and Cell Biology (MMICB), Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Leonard P. Rybak
- Department of Surgery, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Vickram Ramkumar
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
- *Correspondence: Vickram Ramkumar,
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14
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Identification and Characterization of TMEM119-Positive Cells in the Postnatal and Adult Murine Cochlea. Brain Sci 2023; 13:brainsci13030516. [PMID: 36979326 PMCID: PMC10046579 DOI: 10.3390/brainsci13030516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/09/2023] [Accepted: 03/18/2023] [Indexed: 03/22/2023] Open
Abstract
Transmembrane protein 119 (TMEM119) is expressed in a subset of resident macrophage cells of the brain and was proposed as a marker for native brain microglia. The presence of cells expressing TMEM119 in the cochlea has not yet been described. Thus, the present study aimed to characterize the TMEM119-expressing cells of the postnatal and adult cochlea, the latter also after noise exposure. Immunofluorescent staining of cochlear cryosections detected TMEM119 protein in the spiral limbus fibrocytes and the developing stria vascularis at postnatal Day 3. Applying the macrophage marker Iba1 revealed that TMEM119 is not a marker of cochlear macrophages or a subset of them. In the adult murine cochlea, TMEM119 expression was detected in the basal cells of the stria vascularis and the dark mesenchymal cells of the supralimbal zone. Exposure to noise trauma was not associated with a qualitative change in the types or distributions of the TMEM119-expressing cells of the adult cochlea. Western blot analysis indicated a similar TMEM119 protein expression level in the postnatal cochlea and brain tissues. The findings do not support using TMEM119 as a specific microglial or macrophage marker in the cochlea. The precise role of TMEM119 in the cochlea remains to be investigated through functional experiments. TMEM119 expression in the basal cells of the stria vascularis implies a possible role in the gap junction system of the blood–labyrinth barrier and merits further research.
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15
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Ishibashi Y, Sung CYW, Grati M, Chien W. Immune responses in the mammalian inner ear and their implications for AAV-mediated inner ear gene therapy. Hear Res 2023; 432:108735. [PMID: 36965335 DOI: 10.1016/j.heares.2023.108735] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/17/2023] [Accepted: 03/04/2023] [Indexed: 03/13/2023]
Abstract
Adeno-associated virus (AAV)-mediated inner ear gene therapy is a promising treatment option for hearing loss and dizziness. Several studies have shown that AAV-mediated inner ear gene therapy can be applied to various mouse models of hereditary hearing loss to improve their auditory function. Despite the increase in AAV-based animal and clinical studies aiming to rescue auditory and vestibular functions, little is currently known about the host immune responses to AAV in the mammalian inner ear. It has been reported that the host immune response plays an important role in the safety and efficacy of viral-mediated gene therapy. Therefore, in order for AAV-mediated gene therapy to be successfully and safely translated into patients with hearing loss and dizziness, a better understanding of the host immune responses to AAV in the inner ear is critical. In this review, we summarize the current knowledge on host immune responses to AAV-mediated gene therapy in the mammalian inner ear and other organ systems. We also outline the areas of research that are critical for ensuring the safety and efficacy of AAV-mediated inner ear gene therapy in future clinical and translational studies.
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Affiliation(s)
- Yasuko Ishibashi
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Cathy Yea Won Sung
- Laboratory of Hearing Biology and Therapeutics, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, Bethesda, MD, USA
| | - Mhamed Grati
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA
| | - Wade Chien
- Inner Ear Gene Therapy Program, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health, 35A 1F220, 35A Covent Dr., Bethesda, MD 20892, USA; Department of Otolaryngology-Head & Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.
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16
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Barnes CC, Yee KT, Vetter DE. Conditional Ablation of Glucocorticoid and Mineralocorticoid Receptors from Cochlear Supporting Cells Reveals Their Differential Roles for Hearing Sensitivity and Dynamics of Recovery from Noise-Induced Hearing Loss. Int J Mol Sci 2023; 24:3320. [PMID: 36834731 PMCID: PMC9961551 DOI: 10.3390/ijms24043320] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Endogenous glucocorticoids (GC) are known to modulate basic elements of cochlear physiology. These include both noise-induced injury and circadian rhythms. While GC signaling in the cochlea can directly influence auditory transduction via actions on hair cells and spiral ganglion neurons, evidence also indicates that GC signaling exerts effects via tissue homeostatic processes that can include effects on cochlear immunomodulation. GCs act at both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). Most cell types in the cochlea express both receptors sensitive to GCs. The GR is associated with acquired sensorineural hearing loss (SNHL) through its effects on both gene expression and immunomodulatory programs. The MR has been associated with age-related hearing loss through dysfunction of ionic homeostatic balance. Cochlear supporting cells maintain local homeostatic requirements, are sensitive to perturbation, and participate in inflammatory signaling. Here, we have used conditional gene manipulation techniques to target Nr3c1 (GR) or Nr3c2 (MR) for tamoxifen-induced gene ablation in Sox9-expressing cochlear supporting cells of adult mice to investigate whether either of the receptors sensitive to GCs plays a role in protecting against (or exacerbating) noise-induced cochlear damage. We have selected mild intensity noise exposure to examine the role of these receptors related to more commonly experienced noise levels. Our results reveal distinct roles of these GC receptors for both basal auditory thresholds prior to noise exposure and during recovery from mild noise exposure. Prior to noise exposure, auditory brainstem responses (ABRs) were measured in mice carrying the floxed allele of interest and the Cre recombinase transgene, but not receiving tamoxifen injections (defined as control (no tamoxifen treatment), versus conditional knockout (cKO) mice, defined as mice having received tamoxifen injections. Results revealed hypersensitive thresholds to mid- to low-frequencies after tamoxifen-induced GR ablation from Sox9-expressing cochlear supporting cells compared to control (no tamoxifen) mice. GR ablation from Sox9-expressing cochlear supporting cells resulted in a permanent threshold shift in mid-basal cochlear frequency regions after mild noise exposure that produced only a temporary threshold shift in both control (no tamoxifen) f/fGR:Sox9iCre+ and heterozygous f/+GR:Sox9iCre+ tamoxifen-treated mice. A similar comparison of basal ABRs measured in control (no tamoxifen) and tamoxifen-treated, floxed MR mice prior to noise exposure indicated no difference in baseline thresholds. After mild noise exposure, MR ablation was initially associated with a complete threshold recovery at 22.6 kHz by 3 days post-noise. Threshold continued to shift to higher sensitivity over time such that by 30 days post-noise exposure the 22.6 kHz ABR threshold was 10 dB more sensitive than baseline. Further, MR ablation produced a temporary reduction in peak 1 neural amplitude one day post-noise. While supporting cell GR ablation trended towards reducing numbers of ribbon synapses, MR ablation reduced ribbon synapse counts but did not exacerbate noise-induced damage including synapse loss at the experimental endpoint. GR ablation from the targeted supporting cells increased the basal resting number of Iba1-positive (innate) immune cells (no noise exposure) and decreased the number of Iba1-positive cells seven days following noise exposure. MR ablation did not alter innate immune cell numbers at seven days post-noise exposure. Taken together, these findings support differential roles of cochlear supporting cell MR and GR expression at basal, resting conditions and especially during recovery from noise exposure.
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Affiliation(s)
- Charles C. Barnes
- Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Kathleen T. Yee
- Department of Otolaryngology–Head and Neck Surgery, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Douglas E. Vetter
- Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS 39216, USA
- Department of Otolaryngology–Head and Neck Surgery, University of Mississippi Medical Center, Jackson, MS 39216, USA
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17
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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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18
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Liver Fibrosis and Hearing Loss in an Older Mediterranean Population: Results from the Salus in Apulia Study. J Clin Med 2022; 11:jcm11237213. [PMID: 36498787 PMCID: PMC9736605 DOI: 10.3390/jcm11237213] [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: 11/02/2022] [Revised: 11/23/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Background: Aging is the main negative prognostic factor for various chronic diseases, such as liver fibrosis, and clinical disorders such as hearing loss. This study aimed to investigate the association between age-related hearing loss (ARHL) and age-related central auditory processing disorder (CAPD), and the risk for liver fibrosis in a cross-sectional study on an aging population. Methods: Liver fibrosis risk was judged on the fibrosis-4 (FIB-4) score. Peripheral ARHL was evaluated with pure tone audiometry using a calibrated audiometer. The pure tone average (PTA), calculated as a threshold ≤ 40 dB (HL) in the better ear, was measured at the frequencies 0.5−4 kHz. For age-related CAPD assessment, we employed the Synthetic Sentence Identification with an Ipsilateral Competitive Message test (SSI-ICM). General linear Logistic regression models were used to estimate the association. Results: The increase in the PTA 0.5−2 kHz (coefficient: 0.02, SE: 0.01, CI 95%: 0.01 to 0.03) was directly associated with a higher risk of liver fibrosis (FIB-4 ≥ 2.67). Moreover, the reduction in SSI (coefficient: −0.02, SE: 0.01, CI 95%: −0.03 to −0.01) was inversely associated with FIB-4 values < 2.67. Conclusion: Our results show an association between liver fibrosis and both ARHL and CAPD, linked by the typical consequence of aging. We also assume a role of inflammatory responses and oxidative stress.
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Song X, Li Y, Guo R, Yu Q, Liu S, Teng Q, Chen ZR, Xie J, Gong S, Liu K. Cochlear resident macrophage mediates development of ribbon synapses via CX3CR1/CX3CL1 axis. Front Mol Neurosci 2022; 15:1031278. [PMID: 36518186 PMCID: PMC9742371 DOI: 10.3389/fnmol.2022.1031278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/31/2022] [Indexed: 08/11/2023] Open
Abstract
Cochlear ribbon synapses formed between spiral ganglion neurons and inner hair cells in postnatal mice must undergo significant morphological and functional development to reach auditory maturation. However, the mechanisms underlying cochlear ribbon synapse remodeling remain unclear. This study found that cochlear resident macrophages are essential for cochlear ribbon synapse development and maturation in mice via the CX3CR1/CX3CL1 axis. CX3CR1 expression (a macrophage surface-specific receptor) and macrophage count in the cochlea were significantly increased from postnatal day 7 then decreased from days 14 to 28. Seven-day treatment with CX3CR1 inhibitors and artificial upregulation of CX3CL1 levels in the inner ear environment using the semicircular canal injection technique were initiated on day 7, and this resulted in a significant increase in hearing threshold on day 28. Additionally, abnormalities in the morphology and number of cochlear ribbon synapses were detected on day P14, which may be associated with hearing impairment. In conclusion, macrophage regulation of cochlear ribbon synapse remodeling via the CX3CR1/CX3CL1 axis is required during hearing development and offers a new perspective on immune-related hearing loss throughout auditory development. Importantly, it could be a new treatment target for sensorineural hearing loss.
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Affiliation(s)
- Xinyu Song
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Yang Li
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Rui Guo
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Qianru Yu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Shan Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Qi Teng
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Zhong-Rui Chen
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Jing Xie
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, China
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20
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Bedeir MM, Ninoyu Y, Nakamura T, Tsujikawa T, Hirano S. Multiplex immunohistochemistry reveals cochlear macrophage heterogeneity and local auditory nerve inflammation in cisplatin-induced hearing loss. Front Neurol 2022; 13:1015014. [PMID: 36341090 PMCID: PMC9633043 DOI: 10.3389/fneur.2022.1015014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/26/2022] [Indexed: 08/11/2023] Open
Abstract
Inner ear macrophages play a vital role in cochlear homeostasis. Recent studies have demonstrated the existence of macrophages at different sites of the cochlea, with increased cochlear infiltration as an inflammatory response mechanism to injury. However, current methods, such as conventional immunohistochemistry and flow cytometry, provide limited information about the diversity of cochlear macrophages. Recently, multiplex immunohistochemistry (mIHC) successfully identified the heterogeneity of immune cells in cancer tissue and thereby improved our understanding of the disease prognosis. In this study, we modified the mIHC technique for cochlear tissue and utilized it to investigate cochlear macrophage behavior and heterogeneity before and after exposure to ototoxic drugs such as cisplatin. Four-week-old C57BL/6N female mice were intraperitoneally injected with cisplatin at 5 mg/kg/day consecutively for 6 days. Their hearing levels were assessed before and after the injection. Their cochleae were harvested before (day 0) and on days 8 and 15 after the cisplatin injection. Paraffin-embedded sections were sequentially immunostained using macrophage surface markers to identify the different categories of macrophages. Each immunostaining cycle included incubation with primary antibody, incubation with secondary antibody, chromogenic staining, and image scanning. Thereafter, all antibodies were stripped out, and antigen retrieval was performed to prepare the tissue for the next cycle. The results revealed that activated cochlear macrophages were not entirely differentiated into M1 or M2 categories but into multi-marker M1/M2 mixed macrophages. Furthermore, the ratio of these mixed (M1/M2) macrophages to Iba1+ macrophages increased in the auditory nerve after cisplatin exposure, suggesting local auditory nerve inflammation. The increase in the population of activated macrophages in the auditory nerve region was concomitant with the temporary shift of hearing threshold on day 8 post-cisplatin injection. The findings of this study indicate the effectiveness of mIHC in identifying cochlear macrophage heterogeneity both in the resting state and after cisplatin exposure. Therefore, mIHC could be a powerful tool in cochlear immunology research. Our findings may provide new insights into the co-relation between the cochlear macrophage and cisplatin exposure.
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Sargsyan L, Swisher AR, Hetrick AP, Li H. Effects of Combined Gentamicin and Furosemide Treatment on Cochlear Macrophages. Int J Mol Sci 2022; 23:ijms23137343. [PMID: 35806348 PMCID: PMC9266920 DOI: 10.3390/ijms23137343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 12/15/2022] Open
Abstract
Combining aminoglycosides and loop diuretics often serves as an effective ototoxic approach to deafen experimental animals. The treatment results in rapid hair cell loss with extended macrophage presence in the cochlea, creating a sterile inflammatory environment. Although the early recruitment of macrophages is typically neuroprotective, the delay in the resolution of macrophage activity can be a complication if the damaged cochlea is used as a model to study subsequent therapeutic strategies. Here, we applied a high dose combination of systemic gentamicin and furosemide in C57 BL/6 and CBA/CaJ mice and studied the ototoxic consequences in the cochlea, including hair cell survival, ribbon synaptic integrity, and macrophage activation up to 15-day posttreatment. The activity of macrophages in the basilar membrane was correlated to the severity of cochlear damage, particularly the hair cell damage. Comparatively, C57 BL/6 cochleae were more vulnerable to the ototoxic challenge with escalated macrophage activation. In addition, the ribbon synaptic deterioration was disproportionately limited when compared to the degree of outer hair cell loss in CBA/CaJ mice. The innate and differential otoprotection in CBA/CaJ mice appears to be associated with the rapid activation of cochlear macrophages and a certain level of synaptogenesis after the combined gentamicin and furosemide treatment.
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Affiliation(s)
- Liana Sargsyan
- Research Service, VA Loma Linda Healthcare System, Loma Linda, CA 92357, USA; (L.S.); (A.R.S.); (A.P.H.)
| | - Austin R. Swisher
- Research Service, VA Loma Linda Healthcare System, Loma Linda, CA 92357, USA; (L.S.); (A.R.S.); (A.P.H.)
| | - Alisa P. Hetrick
- Research Service, VA Loma Linda Healthcare System, Loma Linda, CA 92357, USA; (L.S.); (A.R.S.); (A.P.H.)
| | - Hongzhe Li
- Research Service, VA Loma Linda Healthcare System, Loma Linda, CA 92357, USA; (L.S.); (A.R.S.); (A.P.H.)
- Department of Otolaryngology-Head and Neck Surgery, Loma Linda University Health, Loma Linda, CA 92354, USA
- Correspondence: or ; Tel.: +1-(909)-825-7084 (ext. 2816); Fax: +1-(909)-796-4508
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22
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Chan J, Telang R, Kociszewska D, Thorne PR, Vlajkovic SM. A High-Fat Diet Induces Low-Grade Cochlear Inflammation in CD-1 Mice. Int J Mol Sci 2022; 23:5179. [PMID: 35563572 PMCID: PMC9101486 DOI: 10.3390/ijms23095179] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 02/04/2023] Open
Abstract
There is growing evidence for a relationship between gut dysbiosis and hearing loss. Inflammatory bowel disease, diet-induced obesity (DIO), and type 2 diabetes have all been linked to hearing loss. Here, we investigated the effect of a chronic high-fat diet (HFD) on the development of inner ear inflammation using a rodent model. Three-week-old CD-1 (Swiss) mice were fed an HFD or a control diet for ten weeks. After ten weeks, mouse cochleae were harvested, and markers of cochlear inflammation were assessed at the protein level using immunohistochemistry and at the gene expression level using quantitative real-time RT-PCR. We identified increased immunoexpression of pro-inflammatory biomarkers in animals on an HFD, including intracellular adhesion molecule 1 (ICAM1), interleukin 6 receptor α (IL6Rα), and toll-like-receptor 2 (TLR2). In addition, increased numbers of ionized calcium-binding adapter molecule 1 (Iba1) positive macrophages were found in the cochlear lateral wall in mice on an HFD. In contrast, gene expression levels of inflammatory markers were not affected by an HFD. The recruitment of macrophages to the cochlea and increased immunoexpression of inflammatory markers in mice fed an HFD provide direct evidence for the association between HFD and cochlear inflammation.
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Affiliation(s)
| | | | | | | | - Srdjan M. Vlajkovic
- Department of Physiology and The Eisdell Moore Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; (J.C.); (R.T.); (D.K.); (P.R.T.)
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Keithley EM. Inner ear immunity. Hear Res 2022; 419:108518. [DOI: 10.1016/j.heares.2022.108518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/26/2022]
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Shin SH, Jung J, Park HR, Sim NS, Choi JY, Bae SH. The Time Course of Monocytes Infiltration After Acoustic Overstimulation. Front Cell Neurosci 2022; 16:844480. [PMID: 35496904 PMCID: PMC9039292 DOI: 10.3389/fncel.2022.844480] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/18/2022] [Indexed: 12/15/2022] Open
Abstract
Cochlea macrophages regulate cochlea inflammation and may harbors the potentials to protect hearing function from injury, including acoustic overstimulation. Cochlea macrophage numbers increase at 3–7 days after acoustic stimulation. However, the exact timing of macrophage infiltration and maturation from inflammatory monocytes is unclear. Furthermore, neutrophils may also be involved in this process. Therefore, in this study, we investigated time-dependent immune cell infiltration, macrophage transformation, and neutrophil involvement following acoustic stimulation. Flow cytometry and immunofluorescence were conducted in C-X3-C motif chemokine receptor 1 (CX3CR1)+/GFP mice after acoustic overstimulation (at baseline and at 1, 2, 3, and 5 days after exposure to 120 dB for 1 h) to identify inflammatory monocytes in the cochlea. RNA-sequencing and quantitative polymerase chain reaction were performed to identify differentially expressed genes. Inflammatory monocytes infiltrated into the lower portion of the lateral wall within 2 days after acoustic overstimulation (dpn), followed by transformation into macrophages at 3–5 dpn via CX3CR1 upregulation and Ly6C downregulation. In addition, inflammatory monocytes were aggregated inside the collecting venule only at 1 dpn. Neutrophils were not a major type of phagocyte during this response. The gene encoding C-C motif chemokine ligand 2 gene was significantly upregulated as early as 3 h after acoustic overstimulation. Given these results, treatment to control immune response after a noise-induced hearing loss should be applied as soon as possible.
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Affiliation(s)
- Seung Ho Shin
- Department of Otorhinolaryngology-Head and Neck Surgery, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea
| | - Jinsei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
- Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Haeng Ran Park
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - Nam Suk Sim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
| | - Jae Young Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
- Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Seong Hoon Bae
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea
- *Correspondence: Seong Hoon Bae,
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Miwa T, Okano T. Role of Inner Ear Macrophages and Autoimmune/Autoinflammatory Mechanisms in the Pathophysiology of Inner Ear Disease. Front Neurol 2022; 13:861992. [PMID: 35463143 PMCID: PMC9019483 DOI: 10.3389/fneur.2022.861992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/02/2022] [Indexed: 12/02/2022] Open
Abstract
Macrophages play important roles in tissue homeostasis and inflammation. Recent studies have revealed that macrophages are dispersed in the inner ear and may play essential roles in eliciting an immune response. Autoinflammatory diseases comprise a family of immune-mediated diseases, some of which involve sensorineural hearing loss, indicating that similar mechanisms may underlie the pathogenesis of immune-mediated hearing loss. Autoimmune inner ear disease (AIED) is an idiopathic disorder characterized by unexpected hearing loss. Tissue macrophages in the inner ear represent a potential target for modulation of the local immune response in patients with AIED/autoinflammatory diseases. In this review, we describe the relationship between cochlear macrophages and the pathophysiology of AIED/autoinflammatory disease.
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Affiliation(s)
- Toru Miwa
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Otolaryngology-Head and Neck Surgery, Tazuke Kofukai Medical Research Institute Kitano Hospital, Osaka, Japan
- *Correspondence: Toru Miwa
| | - Takayuki Okano
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Shin SH, Bae SH, Yoo JE, Jung J, Choi JY. Inflammatory monocytes infiltrate the spiral ligament and migrate to the basilar membrane after noise exposure. Clin Exp Otorhinolaryngol 2022; 15:153-159. [PMID: 35255664 PMCID: PMC9149233 DOI: 10.21053/ceo.2021.00857] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 09/06/2021] [Indexed: 11/22/2022] Open
Abstract
Objectives Noise exposure leads to an increase in the macrophage population. This increment is thought to be caused by the transformation of infiltrated monocytes into macrophages rather than by proliferation of the cochlear resident macrophages. However, studies on infiltrated monocytes in the cochlea are scarce. Thus, we aimed to investigate the infiltration of monocytes and their transformation into macrophages after noise exposure. Methods In wild-type and CX3CR1+/GFP C57/B6 mice, inflammatory monocytes were identified by immunofluorescence of mouse cochlear cells. The findings were confirmed and quantitated by flow cytometry. Results One day after noise exposure, monocytes were identified in the spiral ligament. Flow cytometric analysis confirmed that the monocyte population peaked on post-noise exposure day 1 and decreased thereafter. On day 3 after noise exposure, amoeboid-type macrophages increased in the crista basilaris, and on day 5, they spread to the basilar membrane. Conclusion Infiltrated monocytes were successfully observed 1 day after noise exposure, preceding the increase in the macrophage population. This finding supports the proposal that infiltrated monocytes transform into macrophages.
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Ito T, Kurata N, Fukunaga Y. Tissue-Resident Macrophages in the Stria Vascularis. Front Neurol 2022; 13:818395. [PMID: 35185769 PMCID: PMC8850293 DOI: 10.3389/fneur.2022.818395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/13/2022] [Indexed: 12/20/2022] Open
Abstract
Tissue-resident macrophages play an important role in clearance, development, and regulation of metabolism. They also function as sentinel immune cells, initiating inflammatory responses, clearing inflammatory debris, and maintaining homeostatic tissue environment. In the cochlea, the roles of tissue-resident macrophages include maintaining steady-state tissues, immunological defense, and repairing pathological conditions associated with noise, ototoxic drugs, aging, and various pathogens. Perivascular macrophages (PVMs) are a unique subset of tissue-resident macrophages that are closely associated with blood vessels and have unique expression markers in certain tissues. PVMs are found in the inner ear, brain, skin, liver, and retina. The origin of PVMs in the inner ear is unclear, but they are already present during embryonic development. PVMs are members of the blood labyrinth barrier and regulate blood vessel permeability in the stria vascularis, which lies on the lateral wall of the cochlear duct and is crucial for endocochlear potential formation. The cytoplasm of strial PVMs can contain pigment granules that increase in number with age. Strial PVMs are activated by the loss of Slc26a4 in the cochleae, and they subsequently phagocytose aggregated pigment granules and possibly degenerated intermediate cells. This review summarizes the current knowledge of characteristic features and proposed roles of PVMs in the stria vascularis. We also address macrophage activation and involvement of pigment granules with the loss of Slc26a4 in the cochleae.
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Otsuka KS, Nielson C, Firpo MA, Park AH, Beaudin AE. Early Life Inflammation and the Developing Hematopoietic and Immune Systems: The Cochlea as a Sensitive Indicator of Disruption. Cells 2021; 10:cells10123596. [PMID: 34944105 PMCID: PMC8700005 DOI: 10.3390/cells10123596] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/02/2021] [Accepted: 12/13/2021] [Indexed: 12/22/2022] Open
Abstract
Emerging evidence indicates that perinatal infection and inflammation can influence the developing immune system and may ultimately affect long-term health and disease outcomes in offspring by perturbing tissue and immune homeostasis. We posit that perinatal inflammation influences immune outcomes in offspring by perturbing (1) the development and function of fetal-derived immune cells that regulate tissue development and homeostasis, and (2) the establishment and function of developing hematopoietic stem cells (HSCs) that continually generate immune cells across the lifespan. To disentangle the complexities of these interlinked systems, we propose the cochlea as an ideal model tissue to investigate how perinatal infection affects immune, tissue, and stem cell development. The cochlea contains complex tissue architecture and a rich immune milieu that is established during early life. A wide range of congenital infections cause cochlea dysfunction and sensorineural hearing loss (SNHL), likely attributable to early life inflammation. Furthermore, we show that both immune cells and bone marrow hematopoietic progenitors can be simultaneously analyzed within neonatal cochlear samples. Future work investigating the pathogenesis of SNHL in the context of congenital infection will therefore provide critical information on how perinatal inflammation drives disease susceptibility in offspring.
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Affiliation(s)
- Kelly S. Otsuka
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84112, USA;
| | - Christopher Nielson
- Division of Otolaryngology—Head and Neck Surgery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; (C.N.); (A.H.P.)
| | - Matthew A. Firpo
- Department of Surgery, University of Utah, Salt Lake City, UT 84112, USA;
| | - Albert H. Park
- Division of Otolaryngology—Head and Neck Surgery, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; (C.N.); (A.H.P.)
| | - Anna E. Beaudin
- Division of Hematology and Hematologic Malignancies, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
- Correspondence:
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Liu W, Danckwardt-Lillieström N, Schrott-Fischer A, Glueckert R, Rask-Andersen H. Distribution of Immune Cells Including Macrophages in the Human Cochlea. Front Neurol 2021; 12:781702. [PMID: 34880828 PMCID: PMC8645652 DOI: 10.3389/fneur.2021.781702] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/21/2021] [Indexed: 12/20/2022] Open
Abstract
Background: The human cochlea was earlier believed to lack capacity to mount specific immune responses. Recent studies established that the human cochlea holds macrophages. The cells appear to surveil, dispose of, and restore wasted cells to maintain tissue integrity. Macrophage activities are believed to be the central elements in immune responses and could swiftly defuse invading microbes that enter via adjacent infection-prone areas. This review updates recent human studies in light of the current literature and adds information about chemokine gene expression. Materials and Methods: We analyzed surgically obtained human tissue using immunohistochemistry, confocal microscopy, and multichannel super-resolution structured illumination microscopy. The samples were considered representative of steady-state conditions. Antibodies against the ionized calcium-binding adaptor molecule 1 were used to identify the macrophages. CD68 and CD11b, and the major histocompatibility complex type II (MHCII) and CD4 and CD8 were analyzed. The RNAscope technique was used for fractalkine gene localization. Results: Many macrophages were found around blood vessels in the stria vascularis but not CD4 and CD8 lymphocytes. Amoeboid macrophages were identified in the spiral ganglion with surveilling "antennae" projecting against targeted cells. Synapse-like contacts were seen on spiral ganglion cell bodies richly expressing single CXC3CL gene transcripts. Branching neurite-like processes extended along central and peripheral axons. Active macrophages were occasionally found near degenerating hair cells. Some macrophage-interacting T lymphocytes were observed between the scala tympani wall and Rosenthal's canal. CD4 and CD8 cells were not found in the organ of Corti. Conclusions: The results indicate that the human cochlea is equipped with macrophages and potentially lymphocytes, suggesting both an innate and adaptive immune capacity. A rich expression of fractalkine gene transcripts in spiral ganglion neurons suggest an essential role for auditory nerve protection, as has been demonstrated experimentally. The findings provide further information on the important role of the immune machinery present in the human inner ear and its potential to carry adverse immune reactions, including cytotoxic and foreign body responses. The results can be used to form a rationale for therapies aiming to modulate these immune activities.
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Affiliation(s)
- Wei Liu
- Department of Surgical Sciences, Section of Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Niklas Danckwardt-Lillieström
- Department of Surgical Sciences, Section of Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Anneliese Schrott-Fischer
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Rudolf Glueckert
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University Innsbruck, Innsbruck, Austria
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Section of Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
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Okayasu T, O’Malley JT, Nadol JB. Prevalence of Macrophages Within the Cochlear Vessels Following Cochlear Implantation in the Human: An Immunohistopathological Study Using Anti-Iba1 Antibody. Otol Neurotol 2021; 42:e1470-e1477. [PMID: 34325451 PMCID: PMC8595581 DOI: 10.1097/mao.0000000000003312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS The prevalence of monocyte-derived macrophages within cochlear vessels may increase following cochlear implantation. BACKGROUND Recently, we reported an increase in the number of ionized calcium-binding adaptor molecule 1 (Iba1)-positive macrophages in selected cochlear sites such as the osseous spiral lamina and Rosenthal's canal following cochlear implantation. Activation of the immune system induces the recruitment of monocyte-derived macrophages. The prevalence of monocyte-derived macrophages within cochlear vessels may increase following cochlear implantation. However, the delivery system of macrophages to the human cochlea is incompletely understood. METHODS The prevalence of macrophages and monocytes within cochlear blood vessels in 10 human subjects who had undergone unilateral cochlear implantation was studied by light microscopy using anti-Iba1 immunostaining. The densities of Iba1-positve monocytes per area of lumen of cochlear vessels in the sections near the round window in implanted ears were compared with the contralateral unimplanted ears. The correlation between the densities of Iba1-positve monocytes and the duration (months after the cochlear implantation) was also evaluated. RESULTS The prevalence of Iba1-positive macrophages/monocytes in vessels near the round window in implanted ears (mean 26%, median 21%) was greater than in opposite unimplanted ears (mean 5.2%, median 2.5%: p < 0.01). The density of Iba1-positive monocytes in implanted ears (mean 32, median 16 cells/105 μm2) tended to be greater than that in unimplanted ears (mean 6.6, median 0.93 cells/105 μm2: p = 0.08). The density of Iba1-positive monocytes was significantly correlated with duration of implantation but not in the unimplanted ears. CONCLUSION An increase in prevalence of Iba1-positive macrophages/monocytes within cochlear blood vessels after cochlear implantation was demonstrated. These findings suggest a delivery system of Iba1-positive macrophages through cochlear vessels in human that is ongoing for long duration.
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Affiliation(s)
- Tadao Okayasu
- Otopathology Laboratory, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114 USA
- Department of Otolaryngology, Harvard Medical School-Head and Neck Surgery, 243 Charles Street, Boston, MA 02114 USA
- Department of Otolaryngology-Head and Neck Surgery, Nara Medical University, 840 Shijo-cho, Kashihara city, Nara 634-8522, Japan
| | - Jennifer T. O’Malley
- Otopathology Laboratory, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114 USA
| | - Joseph B. Nadol
- Otopathology Laboratory, Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA 02114 USA
- Department of Otolaryngology, Harvard Medical School-Head and Neck Surgery, 243 Charles Street, Boston, MA 02114 USA
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Manigat LC, Granade ME, Taori S, Miller CA, Vass LR, Zhong XP, Harris TE, Purow BW. Loss of Diacylglycerol Kinase α Enhances Macrophage Responsiveness. Front Immunol 2021; 12:722469. [PMID: 34804012 PMCID: PMC8603347 DOI: 10.3389/fimmu.2021.722469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
The diacylglycerol kinases (DGKs) are a family of enzymes responsible for the conversion of diacylglycerol (DAG) to phosphatidic acid (PA). In addition to their primary function in lipid metabolism, DGKs have recently been identified as potential therapeutic targets in multiple cancers, including glioblastoma (GBM) and melanoma. Aside from its tumorigenic properties, DGKα is also a known promoter of T-cell anergy, supporting a role as a recently-recognized T cell checkpoint. In fact, the only significant phenotype previously observed in Dgka knockout (KO) mice is the enhancement of T-cell activity. Herein we reveal a novel, macrophage-specific, immune-regulatory function of DGKα. In bone marrow-derived macrophages (BMDMs) cultured from wild-type (WT) and KO mice, we observed increased responsiveness of KO macrophages to diverse stimuli that yield different phenotypes, including LPS, IL-4, and the chemoattractant MCP-1. Knockdown (KD) of Dgka in a murine macrophage cell line resulted in similar increased responsiveness. Demonstrating in vivo relevance, we observed significantly smaller wounds in Dgka-/- mice with full-thickness cutaneous burns, a complex wound healing process in which macrophages play a key role. The burned area also demonstrated increased numbers of macrophages. In a cortical stab wound model, Dgka-/- brains show increased Iba1+ cell numbers at the needle track versus that in WT brains. Taken together, these findings identify a novel immune-regulatory checkpoint function of DGKα in macrophages with potential implications for wound healing, cancer therapy, and other settings.
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Affiliation(s)
- Laryssa C. Manigat
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Mitchell E. Granade
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Suchet Taori
- Department of Neurology, Division of Neuro-Oncology, University of Virginia, Charlottesville, VA, United States
| | - Charlotte Anne Miller
- Department of Neurology, Division of Neuro-Oncology, University of Virginia, Charlottesville, VA, United States
| | - Luke R. Vass
- Department of Pathology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Xiao-Ping Zhong
- Division of Allergy and Immunology, Department of Pediatrics, Duke University Medical Center, Durham, NC, United States
| | - Thurl E. Harris
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville, VA, United States
| | - Benjamin W. Purow
- Department of Neurology, Division of Neuro-Oncology, University of Virginia, Charlottesville, VA, United States
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32
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Hough K, Verschuur CA, Cunningham C, Newman TA. Macrophages in the cochlea; an immunological link between risk factors and progressive hearing loss. Glia 2021; 70:219-238. [PMID: 34536249 DOI: 10.1002/glia.24095] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 02/06/2023]
Abstract
Macrophages are abundant in the cochlea; however, their role in hearing loss is not well understood. Insults to the cochlea, such as noise or insertion of a cochlear implant, cause an inflammatory response, which includes activation of tissue-resident macrophages. Activation is characterized by changes in macrophage morphology, mediator expression, and distribution. Evidence from other organs shows activated macrophages can become primed, whereby subsequent insults cause an elevated inflammatory response. Primed macrophages in brain pathologies respond to circulating inflammatory mediators by disproportionate synthesis of inflammatory mediators. This signaling occurs behind an intact blood-brain barrier, similar to the blood-labyrinth barrier in the cochlea. Local tissue damage can occur as the result of mediator release by activated macrophages. Damage is typically localized; however, if it is to structures with limited ability to repair, such as neurons or hair cells within the cochlea, it is feasible that this contributes to the progressive loss of function seen in hearing loss. We propose that macrophages in the cochlea link risk factors and hearing loss. Injury to the cochlea causes local macrophage activation that typically resolves. However, in susceptible individuals, some macrophages enter a primed state. Once primed, these macrophages can be further activated, as a consequence of circulating inflammatory molecules associated with common co-morbidities. Hypothetically, this would lead to further cochlear damage and loss of hearing. We review the evidence for the role of tissue-resident macrophages in the cochlea and propose that cochlear macrophages contribute to the trajectory of hearing loss and warrant further study.
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Affiliation(s)
- Kate Hough
- Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, UK
| | - Carl A Verschuur
- Faculty of Engineering and Physical Sciences, Auditory Implant Centre, University of Southampton, Southampton, UK
| | - Colm Cunningham
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute & Trinity College Institute of Neuroscience (TCIN), Dublin, Ireland
| | - Tracey A Newman
- Clinical and Experimental Sciences, Faculty of Medicine, IfLS, University of Southampton, Southampton, UK
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Zhang Y, Li Y, Fu X, Wang P, Wang Q, Meng W, Wang T, Yang J, Chai R. The Detrimental and Beneficial Functions of Macrophages After Cochlear Injury. Front Cell Dev Biol 2021; 9:631904. [PMID: 34458249 PMCID: PMC8385413 DOI: 10.3389/fcell.2021.631904] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 07/14/2021] [Indexed: 12/20/2022] Open
Abstract
Macrophages are the main intrinsic immune cells in the cochlea; they can be activated and play a complicated role after cochlear injury. Many studies have shown that the number of macrophages and their morphological characteristics within the major cochlear partitions undergo significant changes under various pathological conditions including acoustic trauma, ototoxic drug treatment, age-related cochlear degeneration, selective hair cell (HC) and spiral ganglion neuron (SGN) elimination, and surgery. However, the exact role of these macrophages after cochlear injury is still unclear. Regulating the migration and activity of macrophages may be a therapeutic approach to reduce the risk or magnitude of trauma-induced hearing loss, and this review highlights the role of macrophages on the peripheral auditory structures of the cochlea and elucidate the mechanisms of macrophage injury and the strategies to reduce the injury by regulating macrophage.
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Affiliation(s)
- Yuan Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Department of Otolaryngology Head and Neck, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yiyuan Li
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Xiaolong Fu
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Pengjun Wang
- Department of Otorhinolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - Qin Wang
- Department of Otolaryngology-Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Wei Meng
- Department of Otolaryngology Head and Neck, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Tian Wang
- Department of Otolaryngology-Head and Neck Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Jianming Yang
- Department of Otorhinolaryngology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Renjie Chai
- MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Sciences and Technology, Southeast University, Nanjing, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
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Stothert AR, Kaur T. Innate Immunity to Spiral Ganglion Neuron Loss: A Neuroprotective Role of Fractalkine Signaling in Injured Cochlea. Front Cell Neurosci 2021; 15:694292. [PMID: 34408629 PMCID: PMC8365835 DOI: 10.3389/fncel.2021.694292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/14/2021] [Indexed: 12/20/2022] Open
Abstract
Immune system dysregulation is increasingly being attributed to the development of a multitude of neurodegenerative diseases. This, in large part, is due to the delicate relationship that exists between neurons in the central nervous system (CNS) and peripheral nervous system (PNS), and the resident immune cells that aid in homeostasis and immune surveillance within a tissue. Classically, the inner ear was thought to be immune privileged due to the presence of a blood-labyrinth barrier. However, it is now well-established that both vestibular and auditory end organs in the inner ear contain a resident (local) population of macrophages which are the phagocytic cells of the innate-immune system. Upon cochlear sterile injury or infection, there is robust activation of these resident macrophages and a predominant increase in the numbers of macrophages as well as other types of leukocytes. Despite this, the source, nature, fate, and functions of these immune cells during cochlear physiology and pathology remains unclear. Migration of local macrophages and infiltration of bone-marrow-derived peripheral blood macrophages into the damaged cochlea occur through various signaling cascades, mediated by the release of specific chemical signals from damaged sensory and non-sensory cells of the cochlea. One such signaling pathway is CX3CL1-CX3CR1, or fractalkine (FKN) signaling, a direct line of communication between macrophages and sensory inner hair cells (IHCs) and spiral ganglion neurons (SGNs) of the cochlea. Despite the known importance of this neuron-immune axis in CNS function and pathology, until recently it was not clear whether this signaling axis played a role in macrophage chemotaxis and SGN survival following cochlear injury. In this review, we will explore the importance of innate immunity in neurodegenerative disease development, specifically focusing on the regulation of the CX3CL1-CX3CR1 axis, and present evidence for a role of FKN signaling in cochlear neuroprotection.
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Affiliation(s)
- Andrew Rigel Stothert
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
| | - Tejbeer Kaur
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, NE, United States
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Mao H, Chen Y. Noise-Induced Hearing Loss: Updates on Molecular Targets and Potential Interventions. Neural Plast 2021; 2021:4784385. [PMID: 34306060 PMCID: PMC8279877 DOI: 10.1155/2021/4784385] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/12/2021] [Indexed: 12/18/2022] Open
Abstract
Noise overexposure leads to hair cell loss, synaptic ribbon reduction, and auditory nerve deterioration, resulting in transient or permanent hearing loss depending on the exposure severity. Oxidative stress, inflammation, calcium overload, glutamate excitotoxicity, and energy metabolism disturbance are the main contributors to noise-induced hearing loss (NIHL) up to now. Gene variations are also identified as NIHL related. Glucocorticoid is the only approved medication for NIHL treatment. New pharmaceuticals targeting oxidative stress, inflammation, or noise-induced neuropathy are emerging, highlighted by the nanoparticle-based drug delivery system. Given the complexity of the pathogenesis behind NIHL, deeper and more comprehensive studies still need to be fulfilled.
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Affiliation(s)
- Huanyu Mao
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai 200031, China
| | - Yan Chen
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai 200031, China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai 200031, China
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Celaya AM, Rodríguez-de la Rosa L, Bermúdez-Muñoz JM, Zubeldia JM, Romá-Mateo C, Avendaño C, Pallardó FV, Varela-Nieto I. IGF-1 Haploinsufficiency Causes Age-Related Chronic Cochlear Inflammation and Increases Noise-Induced Hearing Loss. Cells 2021; 10:cells10071686. [PMID: 34359856 PMCID: PMC8304185 DOI: 10.3390/cells10071686] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/28/2021] [Accepted: 06/28/2021] [Indexed: 12/18/2022] Open
Abstract
Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1+/- mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.
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Affiliation(s)
- Adelaida M. Celaya
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
| | - Lourdes Rodríguez-de la Rosa
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
| | - Jose M. Bermúdez-Muñoz
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
| | - José M. Zubeldia
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Allergy Service, Gregorio Marañon General University Hospital, 28009 Madrid, Spain
- Gregorio Marañon Health Research Institute (IiSGM), 28009 Madrid, Spain
| | - Carlos Romá-Mateo
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Spain and FIHCUV-INCLIVA, 46010 Valencia, Spain
| | - Carlos Avendaño
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Department of Anatomy, Histology & Neuroscience, Medical School, Autonomous University of Madrid, 28029 Madrid, Spain
| | - Federico V. Pallardó
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Department of Physiology, Faculty of Medicine and Dentistry, University of Valencia, Spain and FIHCUV-INCLIVA, 46010 Valencia, Spain
| | - Isabel Varela-Nieto
- Institute for Biomedical Research “Alberto Sols” (IIBM), Spanish National Research Council-Autonomous University of Madrid (CSIC-UAM), 28029 Madrid, Spain; (A.M.C.); (J.M.B.-M.); (J.M.Z.)
- Rare Diseases Biomedical Research Networking Centre (CIBERER), The Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; (C.R.-M.); (F.V.P.)
- Hospital La Paz Institute for Health Research (IdiPAZ), 28029 Madrid, Spain;
- Correspondence: (L.R.-d.l.R.); (I.V.-N.)
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Qiang Q, Manalo JM, Sun H, Zhang Y, Song A, Wen AQ, Wen YE, Chen C, Liu H, Cui Y, Nemkov T, Reisz JA, Edwards III G, Perreira FA, Kellems RE, Soto C, D’Alessandro A, Xia Y. Erythrocyte adenosine A2B receptor prevents cognitive and auditory dysfunction by promoting hypoxic and metabolic reprogramming. PLoS Biol 2021; 19:e3001239. [PMID: 34138843 PMCID: PMC8211187 DOI: 10.1371/journal.pbio.3001239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/19/2021] [Indexed: 12/14/2022] Open
Abstract
Hypoxia drives aging and promotes age-related cognition and hearing functional decline. Despite the role of erythrocytes in oxygen (O2) transport, their role in the onset of aging and age-related cognitive decline and hearing loss (HL) remains undetermined. Recent studies revealed that signaling through the erythrocyte adenosine A2B receptor (ADORA2B) promotes O2 release to counteract hypoxia at high altitude. However, nothing is known about a role for erythrocyte ADORA2B in age-related functional decline. Here, we report that loss of murine erythrocyte-specific ADORA2B (eAdora2b-/-) accelerates early onset of age-related impairments in spatial learning, memory, and hearing ability. eAdora2b-/- mice display the early aging-like cellular and molecular features including the proliferation and activation of microglia and macrophages, elevation of pro-inflammatory cytokines, and attenuation of hypoxia-induced glycolytic gene expression to counteract hypoxia in the hippocampus (HIP), cortex, or cochlea. Hypoxia sufficiently accelerates early onset of cognitive and cochlear functional decline and inflammatory response in eAdora2b-/- mice. Mechanistically, erythrocyte ADORA2B-mediated activation of AMP-activated protein kinase (AMPK) and bisphosphoglycerate mutase (BPGM) promotes hypoxic and metabolic reprogramming to enhance production of 2,3-bisphosphoglycerate (2,3-BPG), an erythrocyte-specific metabolite triggering O2 delivery. Significantly, this finding led us to further discover that murine erythroblast ADORA2B and BPGM mRNA levels and erythrocyte BPGM activity are reduced during normal aging. Overall, we determined that erythrocyte ADORA2B-BPGM axis is a key component for anti-aging and anti-age-related functional decline.
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Affiliation(s)
- Qingfen Qiang
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Jeanne M. Manalo
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, Texas, United States of America
| | - Hong Sun
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yujin Zhang
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Anren Song
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Alexander Q. Wen
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- University of California at San Diego, La Jolla, California, United States of America
| | - Y. Edward Wen
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- University of Texas Southwestern Medical School, Dallas, Texas, United States of America
| | - Changhan Chen
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Hong Liu
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ying Cui
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Julie A. Reisz
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - George Edwards III
- University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, Texas, United States of America
- Department of Neurology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Fred A. Perreira
- Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, United States of America
| | - Rodney E. Kellems
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, Texas, United States of America
| | - Claudio Soto
- Department of Neurology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
| | - Angelo D’Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Yang Xia
- Department of Biochemistry and Molecular Biology, The University of Texas McGovern Medical School, Houston, Texas, United States of America
- University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, Texas, United States of America
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Ghosh S, Stansak K, Walters BJ. Cannabinoid Signaling in Auditory Function and Development. Front Mol Neurosci 2021; 14:678510. [PMID: 34079440 PMCID: PMC8165240 DOI: 10.3389/fnmol.2021.678510] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/15/2021] [Indexed: 12/20/2022] Open
Abstract
Plants of the genus Cannabis have been used by humans for millennia for a variety of purposes. Perhaps most notable is the use of certain Cannabis strains for their psychoactive effects. More recently, several biologically active molecules within the plants of these Cannabis strains, called phytocannabinoids or simply cannabinoids, have been identified. Furthermore, within human cells, endogenous cannabinoids, or endocannabinoids, as well as the receptors and secondary messengers that give rise to their neuromodulatory effects, have also been characterized. This endocannabinoid system (ECS) is composed of two primary ligands-anandamide and 2-arachidonyl glycerol; two primary receptors-cannabinoid receptors 1 and 2; and several enzymes involved in biosynthesis and degradation of endocannabinoid ligands including diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL). Here we briefly summarize cannabinoid signaling and review what has been discerned to date with regard to cannabinoid signaling in the auditory system and its roles in normal physiological function as well as pathological conditions. While much has been uncovered regarding cannabinoid signaling in the central nervous system, less attention has been paid to the auditory system specifically. Still, evidence is emerging to suggest that cannabinoid signaling is critical for the development, maturation, function, and survival of cochlear hair cells (HCs) and spiral ganglion neurons (SGNs). Furthermore, cannabinoid signaling can have profound effects on synaptic connectivity in CNS structures related to auditory processing. While clinical cases demonstrate that endogenous and exogenous cannabinoids impact auditory function, this review highlights several areas, such as SGN development, where more research is warranted.
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Affiliation(s)
- Sumana Ghosh
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States
| | - Kendra Stansak
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States
| | - Bradley J Walters
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, United States.,Department of Otolaryngology-Head and Neck Surgery, University of Mississippi Medical Center, Jackson, MS, United States
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Noonan KY, Lopez IA, Ishiyama G, Ishiyama A. Immune Response of Macrophage Population to Cochlear Implantation: Cochlea Immune Cells. Otol Neurotol 2021; 41:1288-1295. [PMID: 32925862 DOI: 10.1097/mao.0000000000002764] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS The presence and distribution of ionized calcium binding adaptor 1 and CD68 macrophages in the human cochlea is altered in cochlear implantation (CI) compared with the normative or nonimplanted cochlea. BACKGROUND It has been hypothesized that CI induces an immunological response in macrophages leading to implant failure or reduced hearing. Macrophages are resident immune cells in human cochlea and have been shown to phagocytize implant material. In animal models, macrophage populations increase with surgical stress and with the introduction of a foreign body. However, the function and response of inner ear macrophages to CI are only beginning to be understood. This study seeks to investigate the inflammatory response to CI by comparing cochlear macrophages in implanted and nonimplanted human temporal bones. METHODS Nineteen temporal bones from nine implanted ears, seven contralateral controls, and three normal control ears were evaluated for the presence and distribution of CD68 and Iba1 expressing positive macrophages. RESULTS Three types of macrophage populations were detected 1) CD68 positive macrophages, 2) Iba1 positive macrophages, and 3) CD68 and Iba1 colocalizing macrophages. Macrophage distribution was ubiquitous: the stria vascularis, Rosenthal canal, and the mid-modiolus intermingled in the spiral ganglia. Iba1 and CD68 macrophages were found in the CI and non-CI contralateral and normal human cochlea. Most ionized calcium binding adaptor 1 expressing macrophages were ramified/amoeboid cells, while CD68 expressing macrophages were round shaped with foamy appearance in some areas. In the CI cochlea, both types of macrophages were detected in the fibrous sheath surrounding the CI path and within fibrotic areas within the scala tympani and the scala vestibuli in the case of CI translocation. In four cases, the density of macrophages was unchanged in the CI compared with the contralateral nonimplanted side, and in three cases, there was an increased number of macrophages in the implanted CI side compared with the nonimplanted side. CONCLUSION Multiple populations of macrophages exist within the cochlea which are present at baseline and in response to trauma from CI. These results further support evidence for a macrophage response to cochlear implantation. Further studies are indicated to evaluate whether these macrophages have a beneficial, detrimental, or a mixed effect in CI patients.
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Affiliation(s)
| | - Ivan A Lopez
- University of California Los Angeles, Los Angeles, California
| | - Gail Ishiyama
- University of California Los Angeles, Los Angeles, California
| | - Akira Ishiyama
- University of California Los Angeles, Los Angeles, California
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The Distribution and Prevalence of Macrophages in the Cochlea Following Cochlear Implantation in the Human: An Immunohistochemical Study Using Anti-Iba1 Antibody. Otol Neurotol 2021; 41:e304-e316. [PMID: 31821256 DOI: 10.1097/mao.0000000000002495] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HYPOTHESIS Cochlear implantation may cause an increase in the number of macrophages in the human cochlea similar to previous findings in the vestibular endorgans. BACKGROUND Macrophages play a key role in both an inflammatory response and homeostatic maintenance. Recently, an increase in the prevalence of macrophages was demonstrated in the human vestibular endorgans after implantation. However, the prevalence of macrophages in the cochlea after implantation is unclear. The aim of this study was to compare the distribution and prevalence of macrophages in implanted human cochleae and the contralateral unimplanted ears. METHODS The prevalence of macrophages in the cochlea in 10 human subjects who had undergone unilateral cochlear implantation was studied by light microscopy using anti-Iba1 immunostaining. The densities of macrophages in the osseous spiral lamina (OSL) and Rosenthal's canal (RC) in implanted cochleae were compared with the contralateral unimplanted ears. The distribution of macrophage morphology (amoeboid, transitional, and ramified) was also compared. RESULTS There were activated and phagocytosing macrophages within the fibrotic sheath surrounding the electrode track and within fibrous tissue with lymphocytic infiltration in implanted ears. The densities of macrophages in OSL and RC in implanted ears were significantly greater than in unimplanted ears in some areas. There was also a difference in the prevalence of macrophage phenotype between the OSL and RC. CONCLUSION An increase in the density of macrophages in the cochlea after cochlear implantation was demonstrated. Both phagocytosis and anti-inflammatory activity of macrophages were suggested by the distribution and prevalence of macrophages in the implanted cochlea.
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Auditory Brainstem Deficits from Early Treatment with a CSF1R Inhibitor Largely Recover with Microglial Repopulation. eNeuro 2021; 8:ENEURO.0318-20.2021. [PMID: 33558268 PMCID: PMC8009669 DOI: 10.1523/eneuro.0318-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/10/2020] [Accepted: 01/13/2021] [Indexed: 12/20/2022] Open
Abstract
Signaling between neurons and glia is necessary for the formation of functional neural circuits. A role for microglia in the maturation of connections in the medial nucleus of the trapezoid body (MNTB) was previously demonstrated by postnatal microglial elimination using a colony stimulating factor 1 receptor (CSF1R). Defective pruning of calyces of Held and significant reduction of the mature astrocyte marker glial fibrillary acidic protein (GFAP) were observed after hearing onset. Here, we investigated the time course required for microglia to populate the mouse MNTB after cessation of CSF1R inhibitor treatment. We then examined whether defects seen after microglial depletion were rectified by microglial repopulation. We found that microglia returned to control levels at four weeks of age (18 d postcessation of treatment). Calyceal innervation of MNTB neurons was comparable to control levels at four weeks and GFAP expression recovered by seven weeks. We further investigated the effects of microglia elimination and repopulation on auditory function using auditory brainstem recordings (ABRs). Temporary microglial depletion significantly elevated auditory thresholds in response to 4. 8, and 12 kHz at four weeks. Treatment significantly affected latencies, interpeak latencies, and amplitudes of all the ABR peaks in response to many of the frequencies tested. These effects largely recovered by seven weeks. These findings highlight the functions of microglia in the formation of auditory neural circuits early in development. Further, the results suggest that microglia retain their developmental functions beyond the period of circuit refinement.
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Baumgartner JE, Baumgartner LS, Baumgartner ME, Moore EJ, Messina SA, Seidman MD, Shook DR. Progenitor cell therapy for acquired pediatric nervous system injury: Traumatic brain injury and acquired sensorineural hearing loss. Stem Cells Transl Med 2021; 10:164-180. [PMID: 33034162 PMCID: PMC7848325 DOI: 10.1002/sctm.20-0026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 12/16/2022] Open
Abstract
While cell therapies hold remarkable promise for replacing injured cells and repairing damaged tissues, cell replacement is not the only means by which these therapies can achieve therapeutic effect. For example, recent publications show that treatment with varieties of adult, multipotent stem cells can improve outcomes in patients with neurological conditions such as traumatic brain injury and hearing loss without directly replacing damaged or lost cells. As the immune system plays a central role in injury response and tissue repair, we here suggest that multipotent stem cell therapies achieve therapeutic effect by altering the immune response to injury, thereby limiting damage due to inflammation and possibly promoting repair. These findings argue for a broader understanding of the mechanisms by which cell therapies can benefit patients.
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Affiliation(s)
- James E. Baumgartner
- Advent Health for ChildrenOrlandoFloridaUSA
- Department of Neurological SurgeryUniversity of Central Florida College of MedicineOrlandoFloridaUSA
| | | | | | - Ernest J. Moore
- Department of Audiology and Speech Language PathologyUniversity of North TexasDentonTexasUSA
| | | | - Michael D. Seidman
- Advent Health CelebrationCelebrationFloridaUSA
- Department of OtorhinolaryngologyUniversity of Central FloridaOrlandoFloridaUSA
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Ríos JD, Hughes CK, Lally J, Wienandt N, Esquivel C, Serhan CN, Weitzel EK. Neuroprotectin D1 Attenuates Blast Overpressure Induced Reactive Microglial Cells in the Cochlea. Laryngoscope 2021; 131:E2018-E2025. [PMID: 33427310 DOI: 10.1002/lary.29337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVE/HYPOTHESIS We examined a neuroinflammatory response associated with glial activation in the cochlea exposed to blast overpressure and evaluated the potential therapeutic efficacy of specialized pro-resolving mediators such as neuroprotectin D1, NPD1; (10R, 17S-dihydroxy-4Z, 7Z, 11E, 13E, 15Z, 19Z-docosahexaenoic acid) in a rodent blast-induced auditory injury model. STUDY DESIGN Animal Research. METHODS A compressed-air driven shock tube was used to expose anesthetized adult male Long-Evan rats to shock waves simulating an open-field blast exposure. Approximately 30 minutes after blast exposure, rats were treated with NPD1 (100 ng/kg body wt.) or vehicle delivered intravenously via tail vein injection. Rats were then euthanized 48 hours after blast exposure. Unexposed rats were included as controls. Tissue sections containing both middle and inner ear were prepared with hematoxylin-eosin staining to elucidate histopathological changes associated with blast exposure. Cochlear tissues were evaluated for relative expression of ionized calcium-binding adaptor 1 (Iba1), as an indicator of microglial activation by immunohistochemistry and western blot analyses. RESULTS Our animal model resulted in an acute injury mechanism manifested by damage to the tympanic membrane, hemorrhage, infiltration of inflammatory cells, and increased expression of Iba1 protein. Moreover, therapeutic intervention with NPD1 significantly reduced Iba1 expression in the cochlea, suggesting a reduction of a neuroinflammatory response caused by blast overpressure. CONCLUSIONS Blast overpressure resulted in an increased expression of proteins involved in gliosis within the auditory system, which were reduced by NPD1. Treatment of NPD1 suggests an effective strategy to reduce or halt auditory microglial cell activation due to primary blast exposure. LEVEL OF EVIDENCE NA Laryngoscope, 131:E2018-E2025, 2021.
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Affiliation(s)
- José David Ríos
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Charlotte K Hughes
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - John Lally
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Nathan Wienandt
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A
| | - Carlos Esquivel
- Department of Defense (DoD) Hearing Center of Excellence, Defense Health Agency, Joint Base San Antonio-Lackland, San Antonio, Texas, U.S.A
| | - Charles N Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital and Department of Anesthesia, Perioperative and Pain Medicine, Harvard Medical School, Boston, Massachusetts, U.S.A
| | - Erik K Weitzel
- US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, U.S.A.,Department of Defense (DoD) Hearing Center of Excellence, Defense Health Agency, Joint Base San Antonio-Lackland, San Antonio, Texas, U.S.A
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44
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Rai V, Wood MB, Feng H, Schabla NM, Tu S, Zuo J. The immune response after noise damage in the cochlea is characterized by a heterogeneous mix of adaptive and innate immune cells. Sci Rep 2020; 10:15167. [PMID: 32938973 PMCID: PMC7495466 DOI: 10.1038/s41598-020-72181-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023] Open
Abstract
Cells of the immune system are present in the adult cochlea and respond to damage caused by noise exposure. However, the types of immune cells involved and their locations within the cochlea are unclear. We used flow cytometry and immunostaining to reveal the heterogeneity of the immune cells in the cochlea and validated the presence of immune cell gene expression by analyzing existing single-cell RNA-sequencing (scRNAseq) data. We demonstrate that cell types of both the innate and adaptive immune system are present in the cochlea. In response to noise damage, immune cells increase in number. B, T, NK, and myeloid cells (macrophages and neutrophils) are the predominant immune cells present. Interestingly, immune cells appear to respond to noise damage by infiltrating the organ of Corti. Our studies highlight the need to further understand the role of these immune cells within the cochlea after noise exposure.
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MESH Headings
- Adaptive Immunity
- Animals
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Cochlea/immunology
- Cochlea/injuries
- Cochlea/pathology
- Disease Models, Animal
- Evoked Potentials, Auditory, Brain Stem/immunology
- Female
- Hearing Loss, Noise-Induced/immunology
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Immunity, Innate
- Killer Cells, Natural/immunology
- Killer Cells, Natural/pathology
- Leukocyte Common Antigens/metabolism
- Macrophages/immunology
- Macrophages/pathology
- Male
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Transgenic
- Neutrophils/immunology
- Neutrophils/pathology
- Organ of Corti/immunology
- Organ of Corti/injuries
- Organ of Corti/pathology
- RNA-Seq
- T-Lymphocytes/immunology
- T-Lymphocytes/pathology
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Affiliation(s)
- Vikrant Rai
- Department of Biomedical Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Megan B Wood
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD, 21205, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Hao Feng
- Department of Biomedical Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Nathan M Schabla
- Department of Medical Microbiology and Immunology and Flow Cytometry Core, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Shu Tu
- Department of Biomedical Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE, 68178, USA
| | - Jian Zuo
- Department of Biomedical Science, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE, 68178, USA.
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
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45
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Szepesy J, Miklós G, Farkas J, Kucsera D, Giricz Z, Gáborján A, Polony G, Szirmai Á, Tamás L, Köles L, Varga ZV, Zelles T. Anti-PD-1 Therapy Does Not Influence Hearing Ability in the Most Sensitive Frequency Range, but Mitigates Outer Hair Cell Loss in the Basal Cochlear Region. Int J Mol Sci 2020; 21:ijms21186701. [PMID: 32933159 PMCID: PMC7555949 DOI: 10.3390/ijms21186701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/29/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
The administration of immune checkpoint inhibitors (ICIs) often leads to immune-related adverse events. However, their effect on auditory function is largely unexplored. Thorough preclinical studies have not been published yet, only sporadic cases and pharmacovigilance reports suggest their significance. Here we investigated the effect of anti-PD-1 antibody treatment (4 weeks, intraperitoneally, 200 μg/mouse, 3 times/week) on hearing function and cochlear morphology in C57BL/6J mice. ICI treatment did not influence the hearing thresholds in click or tone burst stimuli at 4–32 kHz frequencies measured by auditory brainstem response. The number and morphology of spiral ganglion neurons were unaltered in all cochlear turns. The apical-middle turns (<32 kHz) showed preservation of the inner and outer hair cells (OHCs), whilst ICI treatment mitigated the age-related loss of OHCs in the basal turn (>32 kHz). The number of Iba1-positive macrophages has also increased moderately in this high frequency region. We conclude that a 4-week long ICI treatment does not affect functional and morphological integrity of the inner ear in the most relevant hearing range (4–32 kHz; apical-middle turns), but a noticeable preservation of OHCs and an increase in macrophage activity appeared in the >32 kHz basal part of the cochlea.
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Affiliation(s)
- Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gabriella Miklós
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - János Farkas
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Dániel Kucsera
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Pharmahungary Group, H-6722 Szeged, Hungary
| | - Anita Gáborján
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Gábor Polony
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - Ágnes Szirmai
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Tamás
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, H-1083 Budapest, Hungary; (A.G.); (G.P.); (Á.S.); (L.T.)
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
| | - Zoltán V. Varga
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- HCEMM-SU Cardiometabolic Immunology Research Group, Semmelweis University, H-1089 Budapest, Hungary
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary; (J.S.); (G.M.); (J.F.); (D.K.); (Z.G.); (L.K.); (Z.V.V.)
- Department of Pharmacology, Institute of Experimental Medicine, H-1083 Budapest, Hungary
- Correspondence: ; Tel.: +36-1-210-4416/56297; Fax: +36-1-210-4412
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Kanzaki S, Toyoda M, Umezawa A, Ogawa K. Application of Mesenchymal Stem Cell Therapy and Inner Ear Regeneration for Hearing Loss: A Review. Int J Mol Sci 2020; 21:ijms21165764. [PMID: 32796705 PMCID: PMC7460950 DOI: 10.3390/ijms21165764] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 08/07/2020] [Indexed: 02/08/2023] Open
Abstract
Inner and middle ear disorders are the leading cause of hearing loss, and are said to be among the greatest risk factors of dementia. The use of regenerative medicine for the treatment of inner ear disorders may offer a potential alternative to cochlear implants for hearing recovery. In this paper, we reviewed recent research and clinical applications in middle and inner ear regeneration and cell therapy. Recently, the mechanism of inner ear regeneration has gradually been elucidated. "Inner ear stem cells," which may be considered the precursors of various cells in the inner ear, have been discovered in the cochlea and vestibule. Research indicates that cells such as hair cells, neurons, and spiral ligaments may form promising targets for inner ear regenerative therapies by the transplantation of stem cells, including mesenchymal stem cells. In addition, it is necessary to develop tests for the clinical monitoring of cell transplantation. Real-time imaging techniques and hearing rehabilitation techniques are also being investigated, and cell therapy has found clinical application in cochlear implant techniques.
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Affiliation(s)
- Sho Kanzaki
- Department of Otolaryngology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan;
- Correspondence:
| | - Masashi Toyoda
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi, Tokyo 173-0015, Japan;
| | - Akihiro Umezawa
- National Center for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan;
| | - Kaoru Ogawa
- Department of Otolaryngology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan;
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47
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Bae SH, Kwak SH, Yoo JE, Kim KM, Hyun YM, Choi JY, Jung J. Three-Dimensional Distribution of Cochlear Macrophages in the Lateral Wall of Cleared Cochlea. Clin Exp Otorhinolaryngol 2020; 14:179-184. [PMID: 32734741 PMCID: PMC8111389 DOI: 10.21053/ceo.2020.00395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/20/2020] [Indexed: 12/26/2022] Open
Abstract
Objectives Resident macrophages are well known to be present in the cochlea, but the exact patterns thereof in spiral ligaments have not been discussed in previous studies. We sought to document the distribution of macrophages in intact cochleae using three-dimensional imaging. Methods Cochleae were obtained from C-X3-C motif chemokine receptor 1+/GFP mice, and organ clearing was performed. Three-dimensional images of cleared intact cochleae were reconstructed using two-photon microscopy. The locations of individual macrophages were investigated using 100-μm stacked images to reduce bias. Cochlear inflammation was then induced by lipopolysaccharide (LPS) inoculation into the middle ear through the tympanic membrane. Four days after inoculation, three-dimensional images were obtained. Results Macrophages were scarce in areas adjacent to the stria vascularis, particularly the area just beneath it even though many have suspected macrophages to be abundant in this area. This finding remained consistent upon LPS-induced cochlear inflammation, despite a significant increase in the number of macrophages, compared to non-treated cochlea. Conclusion Resident macrophages in spiral ligaments are scarce in areas adjacent to the stria vascularis.
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Affiliation(s)
- Seong Hoon Bae
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Hyun Kwak
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Jee Eun Yoo
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Kyu Min Kim
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Young Min Hyun
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
| | - Jae Young Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Jinsei Jung
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
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48
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Reynolds R, Garner A, Norton J. Sound and Vibration as Research Variables in Terrestrial Vertebrate Models. ILAR J 2020; 60:159-174. [PMID: 32602530 DOI: 10.1093/ilar/ilaa004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 02/07/2020] [Accepted: 02/11/2020] [Indexed: 12/31/2022] Open
Abstract
Sound and vibration have been shown to alter animal behavior and induce physiological changes as well as to cause effects at the cellular and molecular level. For these reasons, both environmental factors have a considerable potential to alter research outcomes when the outcome of the study is dependent on the animal existing in a normal or predictable biological state. Determining the specific levels of sound or vibration that will alter research is complex, as species will respond to different frequencies and have varying frequencies where they are most sensitive. In consideration of the potential of these factors to alter research, a thorough review of the literature and the conditions that likely exist in the research facility should occur specific to each research study. This review will summarize the fundamental physical properties of sound and vibration in relation to deriving maximal level standards, consider the sources of exposure, review the effects on animals, and discuss means by which the adverse effects of these factors can be mitigated.
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Affiliation(s)
- Randall Reynolds
- Duke University School of Medicine, Department of Pathology and Division of Laboratory Animal Resources, Durham, NC
| | - Angela Garner
- Duke University School of Medicine, Division of Laboratory Animal Resources, Durham, NC
| | - John Norton
- Duke University School of Medicine, Pathology and Division of Laboratory Animal Resources
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49
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Yee KT, Neupane B, Bai F, Vetter DE. Zika virus infection causes widespread damage to the inner ear. Hear Res 2020; 395:108000. [PMID: 32623238 DOI: 10.1016/j.heares.2020.108000] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/07/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022]
Abstract
Zika virus (ZIKV) has been recently recognized as a causative agent of newborn microcephaly, as well as other neurological consequences. A less well recognized comorbidity of prenatal ZIKV infection is hearing loss, but cases of hearing impairment following adult ZIKV infection have also been recognized. Diminished hearing following prenatal ZIKV infection in a mouse model has been reported, but no cellular consequences were observed. We examined the effects of ZIKV infection on inner ear cellular integrity and expression levels of various proteins important for cochlear function in type I interferon receptor null (Ifnar1-/-) mice following infection at 5-6 weeks of age. We show that ZIKV antigens are present in cells within the cochlear epithelium, lateral wall, spiral limbus and spiral ganglion. Here we show that ZIKV infection alters cochlear expression of genes that signal cell damage (S100B), transport fluids (AQP1), are gaseous transmitters (eNOs) and modulate immune response (F4/80). Morphological analyses shows that not only are cochlear structures compromised by ZIKV infection, but damage also occurs in vestibular end organs. ZIKV produces a graded distribution of cellular damage in the cochlea, with greatest damage in the apex similar to that reported for cytomegalovirus (CMV) infection. The graded distribution of damage may indicate a differential susceptibility to ZIKV along the cochlear tonotopic axis. Collectively, these data are the first to show the molecular and morphological damage to the inner ear induced by ZIKV infection in adults and suggests multiple mechanisms contributing to the hearing loss reported in the human population.
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Affiliation(s)
- Kathleen T Yee
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39202, USA
| | - Biswas Neupane
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Fengwei Bai
- Department of Cell and Molecular Biology, University of Southern Mississippi, Hattiesburg, MS, 39406, USA.
| | - Douglas E Vetter
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39202, USA.
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50
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Zhang C, Frye MD, Sun W, Sharma A, Manohar S, Salvi R, Hu BH. New insights on repeated acoustic injury: Augmentation of cochlear susceptibility and inflammatory reaction resultant of prior acoustic injury. Hear Res 2020; 393:107996. [PMID: 32534268 DOI: 10.1016/j.heares.2020.107996] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 04/29/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022]
Abstract
In industrial and military settings, individuals who suffer from one episode of acoustic trauma are likely to sustain another episode of acoustic stress, creating an opportunity for a potential interaction between the two stress conditions. We previously demonstrated that acoustic overstimulation perturbs the cochlear immune environment. However, how the cochlear immune system responds to repeated acoustic overstimulation is unknown. Here, we used a mouse model to investigate the cochlear immune response to repeated stress. We reveal that exposure to an intense noise at 120 dB SPL for 1 h activates the cochlear immune response in a time-dependent fashion with substantial expansion and activation of the macrophage population in the cochlea at 2-days post-exposure. At 20-days post-exposure, the number and pro-inflammatory phenotypes of cochlear macrophages have significantly subsided, but have yet to return to homeostatic levels. Monocytes with anti-inflammatory phenotypes are recruited into the cochlea. With the presence of this residual immune activation, a second exposure to the same noise provokes an exaggerated inflammatory response as evidenced by exacerbated maturation of macrophages. Furthermore, the second noise causes greater sensory cell pathogenesis. Unlike the first noise-induced damage that occurs mainly between 0 and 2 days post-exposure, the second noise-induced damage occurs more frequently between 2 and 20 days post-exposure, the period when secondary damage takes place. These observations suggest that repeated acoustic overstimulation exacerbates cochlear inflammation and secondary sensory cell pathogenesis. Together, our results suggest that the cochlear immune system plays an important role in modulating cochlear responses to repeated acoustic stress.
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Affiliation(s)
- Celia Zhang
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Mitchell D Frye
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Wei Sun
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Ashu Sharma
- Department of Oral Biology, University at Buffalo, School of Dental Medicine, University of Buffalo, The State University of New York, Buffalo, NY, USA, 14214.
| | - Senthilvelan Manohar
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| | - Bo Hua Hu
- Center for Hearing and Deafness, University at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
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