1
|
Ma X, Guo J, Tian M, Fu Y, Jiang P, Zhang Y, Chai R. Advance and Application of Single-cell Transcriptomics in Auditory Research. Neurosci Bull 2024; 40:963-980. [PMID: 38015350 PMCID: PMC11250760 DOI: 10.1007/s12264-023-01149-z] [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: 06/27/2023] [Accepted: 08/03/2023] [Indexed: 11/29/2023] Open
Abstract
Hearing loss and deafness, as a worldwide disability disease, have been troubling human beings. However, the auditory organ of the inner ear is highly heterogeneous and has a very limited number of cells, which are largely uncharacterized in depth. Recently, with the development and utilization of single-cell RNA sequencing (scRNA-seq), researchers have been able to unveil the complex and sophisticated biological mechanisms of various types of cells in the auditory organ at the single-cell level and address the challenges of cellular heterogeneity that are not resolved through by conventional bulk RNA sequencing (bulk RNA-seq). Herein, we reviewed the application of scRNA-seq technology in auditory research, with the aim of providing a reference for the development of auditory organs, the pathogenesis of hearing loss, and regenerative therapy. Prospects about spatial transcriptomic scRNA-seq, single-cell based genome, and Live-seq technology will also be discussed.
Collapse
Affiliation(s)
- Xiangyu Ma
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Jiamin Guo
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Mengyao Tian
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Yaoyang Fu
- Department of Psychiatry, Affiliated Hangzhou First People's Hospital, Zhejiang University school of Medicine, Hangzhou, 310030, China
| | - Pei Jiang
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China
| | - Yuan Zhang
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China
- Research Institute of Otolaryngology, Nanjing, 210008, China
| | - Renjie Chai
- State Key Laboratory of Digital Medical Engineering, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, School of Life Sciences and Technology, Advanced Institute for Life and Health, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 210096, China.
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, 101408, China.
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China.
| |
Collapse
|
2
|
Gansemer BM, Rahman MT, Zhang Z, Green SH. Spiral ganglion neuron degeneration in aminoglycoside-deafened rats involves innate and adaptive immune responses not requiring complement. Front Mol Neurosci 2024; 17:1389816. [PMID: 38840777 PMCID: PMC11151750 DOI: 10.3389/fnmol.2024.1389816] [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: 02/22/2024] [Accepted: 04/29/2024] [Indexed: 06/07/2024] Open
Abstract
Spiral ganglion neurons (SGNs) transmit auditory information from cochlear hair cells to the brain. SGNs are thus not only important for normal hearing, but also for effective functioning of cochlear implants, which stimulate SGNs when hair cells are missing. SGNs slowly degenerate following aminoglycoside-induced hair cell loss, a process thought to involve an immune response. However, the specific immune response pathways involved remain unknown. We used RNAseq to gain a deeper understanding immune-related and other transcriptomic changes that occur in the rat spiral ganglion after kanamycin-induced deafening. Among the immune and inflammatory genes that were selectively upregulated in deafened spiral ganglia, the complement cascade genes were prominent. We then assessed SGN survival, as well as immune cell numbers and activation, in the spiral ganglia of rats with a CRISPR-Cas9-mediated knockout of complement component 3 (C3). Similar to previous findings in our lab and other deafened rodent models, we observed an increase in macrophage number and increased expression of CD68, a marker of phagocytic activity and cell activation, in macrophages in the deafened ganglia. Moreover, we found an increase in MHCII expression on spiral ganglion macrophages and an increase in lymphocyte number in the deafened ganglia, suggestive of an adaptive immune response. However, C3 knockout did not affect SGN survival or increase in macrophage number/activation, implying that complement activation does not play a role in SGN death after deafening. Together, these data suggest that both innate and adaptive immune responses are activated in the deafened spiral ganglion, with the adaptive response directly contributing to cochlear neurodegeneration.
Collapse
Affiliation(s)
| | | | | | - Steven H. Green
- Department of Biology, University of Iowa, Iowa City, IA, United States
| |
Collapse
|
3
|
Zhang Y, Ye F, Fu X, Li S, Wang L, Chen Y, Li H, Hao S, Zhao K, Feng Q, Li P. Mitochondrial Regulation of Macrophages in Innate Immunity and Diverse Roles of Macrophages During Cochlear Inflammation. Neurosci Bull 2024; 40:255-267. [PMID: 37391607 PMCID: PMC10838870 DOI: 10.1007/s12264-023-01085-y] [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: 02/14/2023] [Accepted: 05/05/2023] [Indexed: 07/02/2023] Open
Abstract
Macrophages are essential components of the innate immune system and constitute a non-specific first line of host defense against pathogens and inflammation. Mitochondria regulate macrophage activation and innate immune responses in various inflammatory diseases, including cochlear inflammation. The distribution, number, and morphological characteristics of cochlear macrophages change significantly across different inner ear regions under various pathological conditions, including noise exposure, ototoxicity, and age-related degeneration. However, the exact mechanism underlying the role of mitochondria in macrophages in auditory function remains unclear. Here, we summarize the major factors and mitochondrial signaling pathways (e.g., metabolism, mitochondrial reactive oxygen species, mitochondrial DNA, and the inflammasome) that influence macrophage activation in the innate immune response. In particular, we focus on the properties of cochlear macrophages, activated signaling pathways, and the secretion of inflammatory cytokines after acoustic injury. We hope this review will provide new perspectives and a basis for future research on cochlear inflammation.
Collapse
Affiliation(s)
- Yuan Zhang
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Fanglei Ye
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Xiaolong Fu
- Shandong Provincial Hospital, Shandong First Medical University, Jinan, 250000, China
| | - Shen Li
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Le Wang
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yutian Chen
- The Department of Endovascular Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Hongmin Li
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Shaojuan Hao
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Kun Zhao
- Department of Otology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Qi Feng
- Department of Integrated Traditional and Western Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
- Henan Province Research Center of Kidney Disease, Zhengzhou, 450052, China.
| | - Peipei Li
- Department of Integrated Traditional and Western Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
- Henan Province Research Center of Kidney Disease, Zhengzhou, 450052, China.
| |
Collapse
|
4
|
Paciello F, Pisani A, Rolesi R, Montuoro R, Mohamed-Hizam V, Boni G, Ripoli C, Galli J, Sisto R, Fetoni AR, Grassi C. Oxidative stress and inflammation cause auditory system damage via glial cell activation and dysregulated expression of gap junction proteins in an experimental model of styrene-induced oto/neurotoxicity. J Neuroinflammation 2024; 21:4. [PMID: 38178142 PMCID: PMC10765700 DOI: 10.1186/s12974-023-02996-3] [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: 08/04/2023] [Accepted: 12/13/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Redox imbalance and inflammation have been proposed as the principal mechanisms of damage in the auditory system, resulting in functional alterations and hearing loss. Microglia and astrocytes play a crucial role in mediating oxidative/inflammatory injury in the central nervous system; however, the role of glial cells in the auditory damage is still elusive. OBJECTIVES Here we investigated glial-mediated responses to toxic injury in peripheral and central structures of the auditory pathway, i.e., the cochlea and the auditory cortex (ACx), in rats exposed to styrene, a volatile compound with well-known oto/neurotoxic properties. METHODS Male adult Wistar rats were treated with styrene (400 mg/kg daily for 3 weeks, 5/days a week). Electrophysiological, morphological, immunofluorescence and molecular analyses were performed in both the cochlea and the ACx to evaluate the mechanisms underlying styrene-induced oto/neurotoxicity in the auditory system. RESULTS We showed that the oto/neurotoxic insult induced by styrene increases oxidative stress in both cochlea and ACx. This was associated with macrophages and glial cell activation, increased expression of inflammatory markers (i.e., pro-inflammatory cytokines and chemokine receptors) and alterations in connexin (Cxs) and pannexin (Panx) expression, likely responsible for dysregulation of the microglia/astrocyte network. Specifically, we found downregulation of Cx26 and Cx30 in the cochlea, and high level of Cx43 and Panx1 in the ACx. CONCLUSIONS Collectively, our results provide novel evidence on the role of immune and glial cell activation in the oxidative/inflammatory damage induced by styrene in the auditory system at both peripheral and central levels, also involving alterations of gap junction networks. Our data suggest that targeting glial cells and connexin/pannexin expression might be useful to attenuate oxidative/inflammatory damage in the auditory system.
Collapse
Affiliation(s)
- Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Anna Pisani
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Rolando Rolesi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Raffaele Montuoro
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Giammarco Boni
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| | - Jacopo Galli
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
- Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Renata Sisto
- Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Italian Workers' Compensation Authority (INAIL), Monte Porzio Catone, Rome, Italy
| | - Anna Rita Fetoni
- Department of Neuroscience, Unit of Audiology, Università Degli Studi di Napoli Federico II, Naples, Italy.
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168, Rome, Italy
| |
Collapse
|
5
|
Sung CYW, Hayase N, Yuen PST, Lee J, Fernandez K, Hu X, Cheng H, Star RA, Warchol ME, Cunningham LL. Macrophage Depletion Protects Against Cisplatin-Induced Ototoxicity and Nephrotoxicity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567274. [PMID: 38014097 PMCID: PMC10680818 DOI: 10.1101/2023.11.16.567274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Cisplatin is a widely used and highly effective anti-cancer drug with significant side effects including ototoxicity and nephrotoxicity. Macrophages, the major resident immune cells in the cochlea and kidney, are important drivers of both inflammatory and tissue repair responses. To investigate the roles of macrophages in cisplatin-induced ototoxicity and nephrotoxicity, we used PLX3397, an FDA-approved inhibitor of the colony-stimulating factor 1 receptor (CSF1R), to eliminate tissue-resident macrophages during the course of cisplatin administration. Mice treated with cisplatin alone (cisplatin/vehicle) had significant hearing loss (ototoxicity) as well as kidney injury (nephrotoxicity). Macrophage ablation using PLX3397 resulted in significantly reduced hearing loss measured by auditory brainstem responses (ABR) and distortion-product otoacoustic emissions (DPOAE). Sensory hair cells in the cochlea were protected against cisplatin-induced death in mice treated with PLX3397. Macrophage ablation also protected against cisplatin-induced nephrotoxicity, as evidenced by markedly reduced tubular injury and fibrosis as well as reduced plasma blood urea nitrogen (BUN) and neutrophil gelatinase-associated lipocalin (NGAL) levels. Mechanistically, our data suggest that the protective effect of macrophage ablation against cisplatin-induced ototoxicity and nephrotoxicity is mediated by reduced platinum accumulation in both the inner ear and the kidney. Together our data indicate that ablation of tissue-resident macrophages represents a novel strategy for mitigating cisplatin-induced ototoxicity and nephrotoxicity. Brief summary Macrophage ablation using PLX3397 was protective against cisplatin-induced ototoxicity and nephrotoxicity by limiting platinum accumulation in the inner ear and kidney.
Collapse
|
6
|
Shimada MD, Noda M, Koshu R, Takaso Y, Sugimoto H, Ito M, Yoshizaki T, Hori O. Macrophage depletion attenuates degeneration of spiral ganglion neurons in kanamycin-induced unilateral hearing loss model. Sci Rep 2023; 13:16741. [PMID: 37798459 PMCID: PMC10555992 DOI: 10.1038/s41598-023-43927-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/30/2023] [Indexed: 10/07/2023] Open
Abstract
Pathological conditions in cochlea, such as ototoxicity, acoustic trauma, and age-related cochlear degeneration, induce cell death in the organ of Corti and degeneration of the spiral ganglion neurons (SGNs). Although macrophages play an essential role after cochlear injury, its role in the SGNs is limitedly understood. We analyzed the status of macrophage activation and neuronal damage in the spiral ganglion after kanamycin-induced unilateral hearing loss in mice. The number of ionized calcium-binding adapter molecule 1 (Iba1)-positive macrophages increased 3 days after unilateral kanamycin injection. Macrophages showed larger cell bodies, suggesting activation status. Interestingly, the number of activating transcription factor 3 (ATF3)-positive-neurons, an indicator of early neuronal damage, also increased at the same timing. In the later stages, the number of macrophages decreased, and the cell bodies became smaller, although the number of neuronal deaths increased. To understand their role in neuronal damage, macrophages were depleted via intraperitoneal injection of clodronate liposome 24 h after kanamycin injection. Macrophage depletion decreased the number of ATF3-positive neurons at day 3 and neuronal death at day 28 in the spiral ganglion following kanamycin injection. Our results suggest that suppression of inflammation by clodronate at early timing can protect spiral ganglion damage following cochlear insult.
Collapse
Affiliation(s)
- Mari Dias Shimada
- Department of Otolaryngology, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Masao Noda
- Department of Pediatric Otolaryngology, Jichi Children's Medical Center Tochigi, Jichi Medical University, Shimotsuke, Tochigi, Japan
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Ryota Koshu
- Department of Otolaryngology, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Yuji Takaso
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hisashi Sugimoto
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Makoto Ito
- Department of Pediatric Otolaryngology, Jichi Children's Medical Center Tochigi, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Tomokazu Yoshizaki
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Osamu Hori
- Department of Neuroanatomy, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan.
| |
Collapse
|
7
|
Schiel V, Xia A, Santa Maria PL. Influence of CX3CR1 Deletion on Cochlear Hair Cell Survival and Macrophage Expression in Chronic Suppurative Otitis Media. Otol Neurotol 2023; 44:605-610. [PMID: 37315234 PMCID: PMC10275455 DOI: 10.1097/mao.0000000000003884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
OBJECTIVE Our objective was to determine whether the receptor CX3CR1 is necessary for the recruitment of macrophages to the cochlea in chronic suppurative otitis media (CSOM) and if its deletion can prevent hair cell loss in CSOM. BACKGROUND CSOM is a neglected disease that afflicts 330 million people worldwide and is the most common cause of permanent hearing loss among children in the developing world. It is characterized by a chronically discharging infected middle ear. We have previously demonstrated that CSOM causes macrophage associated sensory hearing loss. The receptor CX3CR1 is expressed on macrophages, which have been shown to be increased at the time point of outer hair cell (OHC) loss in CSOM. METHODS In this report, we examine the influence of CX3CR1 deletion (CX3CR1-/-) in a validated model of Pseudomonas aeruginosa (PA) CSOM. RESULTS The data show no difference in OHC loss between the CX3CR1-/- CSOM group and CX3CR1+/+ CSOM group (p = 0.28). We observed partial OHC loss in the cochlear basal turn, no OHC loss in the middle and apical turns in both CX3CR1-/- and CX3CR1+/+ CSOM mice at 14 days after bacterial inoculation. No inner hair cell (IHC) loss was found in all cochlear turns in all groups. We also counted F4/80 labeled macrophages in the spiral ganglion, spiral ligament, stria vascularis and spiral limbus of the basal, middle, and apical turn in cryosections. We did not find a significant difference in the total number of cochlear macrophages between CX3CR1-/- mice and CX3CR1+/+ mice (p = 0.97). CONCLUSION The data did not support a role for CX3CR1 macrophage associated HC loss in CSOM.
Collapse
Affiliation(s)
- Viktoria Schiel
- Department of Otolaryngology, Head and Neck Surgery, Stanford University, Palo Alto, California
| | | | | |
Collapse
|
8
|
Manickam V, Gawande DY, Stothert AR, Clayman AC, Batalkina L, Warchol ME, Ohlemiller KK, Kaur T. Macrophages Promote Repair of Inner Hair Cell Ribbon Synapses following Noise-Induced Cochlear Synaptopathy. J Neurosci 2023; 43:2075-2089. [PMID: 36810227 PMCID: PMC10039750 DOI: 10.1523/jneurosci.1273-22.2023] [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: 06/26/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/23/2023] Open
Abstract
Resident cochlear macrophages rapidly migrate into the inner hair cell synaptic region and directly contact the damaged synaptic connections after noise-induced synaptopathy. Eventually, such damaged synapses are spontaneously repaired, but the precise role of macrophages in synaptic degeneration and repair remains unknown. To address this, cochlear macrophages were eliminated using colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622. Sustained treatment with PLX5622 in CX3CR1 GFP/+ mice of both sexes led to robust elimination of resident macrophages (∼94%) without significant adverse effects on peripheral leukocytes, cochlear function, and structure. At 1 day (d) post noise exposure of 93 or 90 dB SPL for 2 hours, the degree of hearing loss and synapse loss were comparable in the presence and absence of macrophages. At 30 d after exposure, damaged synapses appeared repaired in the presence of macrophages. However, in the absence of macrophages, such synaptic repair was significantly reduced. Remarkably, on cessation of PLX5622 treatment, macrophages repopulated the cochlea, leading to enhanced synaptic repair. Elevated auditory brainstem response thresholds and reduced auditory brainstem response Peak 1 amplitudes showed limited recovery in the absence of macrophages but recovered similarly with resident and repopulated macrophages. Cochlear neuron loss was augmented in the absence of macrophages but showed preservation with resident and repopulated macrophages after noise exposure. While the central auditory effects of PLX5622 treatment and microglia depletion remain to be investigated, these data demonstrate that macrophages do not affect synaptic degeneration but are necessary and sufficient to restore cochlear synapses and function after noise-induced synaptopathy.SIGNIFICANCE STATEMENT The synaptic connections between cochlear inner hair cells and spiral ganglion neurons can be lost because of noise over exposure or biological aging. This loss may represent the most common causes of sensorineural hearing loss also known as hidden hearing loss. Synaptic loss results in degradation of auditory information, leading to difficulty in listening in noisy environments and other auditory perceptual disorders. We demonstrate that resident macrophages of the cochlea are necessary and sufficient to restore synapses and function following synaptopathic noise exposure. Our work reveals a novel role for innate-immune cells, such as macrophages in synaptic repair, that could be harnessed to regenerate lost ribbon synapses in noise- or age-linked cochlear synaptopathy, hidden hearing loss, and associated perceptual anomalies.
Collapse
Affiliation(s)
- Vijayprakash Manickam
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178
| | - Dinesh Y Gawande
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178
| | - Andrew R Stothert
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178
| | - Anna C Clayman
- Department of Otolaryngology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Lyudmila Batalkina
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178
| | - Mark E Warchol
- Department of Otolaryngology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Kevin K Ohlemiller
- Department of Otolaryngology, School of Medicine, Washington University, St. Louis, Missouri 63110
| | - Tejbeer Kaur
- Department of Biomedical Sciences, School of Medicine, Creighton University, Omaha, Nebraska 68178
| |
Collapse
|
9
|
Rahman MT, Bailey EM, Gansemer BM, Pieper AA, Manak JR, Green SH. Anti-inflammatory Therapy Protects Spiral Ganglion Neurons After Aminoglycoside Antibiotic-Induced Hair Cell Loss. Neurotherapeutics 2023; 20:578-601. [PMID: 36697994 PMCID: PMC10121993 DOI: 10.1007/s13311-022-01336-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2022] [Indexed: 01/26/2023] Open
Abstract
Destruction of cochlear hair cells by aminoglycoside antibiotics leads to gradual death of the spiral ganglion neurons (SGNs) that relay auditory information to the brain, potentially limiting the efficacy of cochlear implants. Because the reasons for this cochlear neurodegeneration are unknown, there are no neuroprotective strategies for patients. To investigate this problem, we assessed transcriptomic changes in the rat spiral ganglion following aminoglycoside antibiotic (kanamycin)-induced hair cell destruction. We observed selectively increased expression of immune and inflammatory response genes and increased abundance of activated macrophages in spiral ganglia by postnatal day 32 in kanamycin-deafened rats, preceding significant SGN degeneration. Treatment with the anti-inflammatory medications dexamethasone and ibuprofen diminished long-term SGN degeneration. Ibuprofen and dexamethasone also diminished macrophage activation. Efficacy of ibuprofen treatment was augmented by co-administration of the nicotinamide adenine dinucleotide-stabilizing agent P7C3-A20. Our results support a critical role of neuroinflammation in SGN degeneration after aminoglycoside antibiotic-mediated cochlear hair cell loss, as well as a neuroprotective strategy that could improve cochlear implant efficacy.
Collapse
Affiliation(s)
- Muhammad T Rahman
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Erin M Bailey
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
| | | | - Andrew A Pieper
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA
- Department of Psychiatry, Case Western Reserve University, Cleveland, OH, 44106, USA
- Geriatric Psychiatry, GRECC, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, 44106, USA
- Institute for Transformative Molecular Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - J Robert Manak
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
- Department of Pediatrics, University of Iowa, Iowa City, IA, 52242, USA
| | - Steven H Green
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA.
| |
Collapse
|
10
|
Denans N, Tran NTT, Swall ME, Diaz DC, Blanck J, Piotrowski T. An anti-inflammatory activation sequence governs macrophage transcriptional dynamics during tissue injury in zebrafish. Nat Commun 2022; 13:5356. [PMID: 36127326 PMCID: PMC9489698 DOI: 10.1038/s41467-022-33015-3] [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: 11/24/2021] [Accepted: 08/26/2022] [Indexed: 11/23/2022] Open
Abstract
Macrophages are essential for tissue repair and regeneration. Yet, the molecular programs, as well as the timing of their activation during and after tissue injury are poorly defined. Using a high spatio-temporal resolution single cell analysis of macrophages coupled with live imaging after sensory hair cell death in zebrafish, we find that the same population of macrophages transitions through a sequence of three major anti-inflammatory activation states. Macrophages first show a signature of glucocorticoid activation, then IL-10 signaling and finally the induction of oxidative phosphorylation by IL-4/Polyamine signaling. Importantly, loss-of-function of glucocorticoid and IL-10 signaling shows that each step of the sequence is independently activated. Lastly, we show that IL-10 and IL-4 signaling act synergistically to promote synaptogenesis between hair cells and efferent neurons during regeneration. Our results show that macrophages, in addition to a switch from M1 to M2, sequentially and independently transition though three anti-inflammatory pathways in vivo during tissue injury in a regenerating organ.
Collapse
Affiliation(s)
- Nicolas Denans
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA.
| | - Nhung T T Tran
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA
| | - Madeleine E Swall
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA
| | - Daniel C Diaz
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA
- Parse Biosciences, 201 Elliott Ave W, Suite 290, Seattle, WA, 98119, USA
| | - Jillian Blanck
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA
| | - Tatjana Piotrowski
- Stowers Institute for Medical Research, 1000 east 50th street, Kansas City, MO, 64110, USA.
| |
Collapse
|
11
|
Steinacher C, Chacko LJ, Liu W, Rask-Andersen H, Bader W, Dudas J, Sergi CM, Dhanaseelan T, Moreno N, Glueckert R, Hoermann R, Schrott-Fischer A. Visualization of macrophage subsets in the development of the fetal human inner ear. Front Immunol 2022; 13:965196. [PMID: 36159857 PMCID: PMC9501668 DOI: 10.3389/fimmu.2022.965196] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/12/2022] [Indexed: 11/13/2022] Open
Abstract
Background Human inner ear contains macrophages whose functional role in early development is yet unclear. Recent studies describe inner ear macrophages act as effector cells of the innate immune system and are often activated following acoustic trauma or exposure to ototoxic drugs. Few or limited literature describing the role of macrophages during inner ear development and organogenesis. Material and Methods We performed a study combining immunohistochemistry and immunofluorescence using antibodies against IBA1, CX3CL1, CD168, CD68, CD45 and CollagenIV. Immune staining and quantification was performed on human embryonic inner ear sections from gestational week 09 to 17. Results The study showed IBA1 and CD45 positive cells in the mesenchymal tissue at GW 09 to GW17. No IBA1 positive macrophages were detected in the sensory epithelium of the cochlea and vestibulum. Fractalkine (CX3CL1) signalling was initiated GW10 and parallel chemotactic attraction and migration of macrophages into the inner ear. Macrophages also migrated into the spiral ganglion, cochlear nerve, and peripheral nerve fibers and tissue-expressing CX3CL1. The mesenchymal tissue at all gestational weeks expressed CD163 and CD68. Conclusion Expressions of markers for resident and non-resident macrophages (IBA1, CD45, CD68, and CD163) were identified in the human fetal inner ear. We speculate that these cells play a role for the development of human inner ear tissue including shaping of the gracile structures.
Collapse
Affiliation(s)
- Claudia Steinacher
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Lejo Johnson Chacko
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wei Liu
- Department of Surgical Sciences, Section of Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Section of Otorhinolaryngology and Head and Neck Surgery, Uppsala University, Uppsala, Sweden
| | - Werner Bader
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jozsef Dudas
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Consolato M. Sergi
- Anatomic Pathology Division, Children’s Hospital of Eastern Ontario (CHEO), University of Ottawa, Ottawa, Canada
| | - Tamilvendhan Dhanaseelan
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Nadjeda Moreno
- Developmental Biology and Cancer, University College London (UCL) Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Rudolf Glueckert
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Romed Hoermann
- Department of Anatomy, Histology & Embryology, Division of Clinical & Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Anneliese Schrott-Fischer
- Inner Ear Laboratory, Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
- *Correspondence: Anneliese Schrott-Fischer,
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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]
|
14
|
Edvardsson Rasmussen J, Lundström P, Eriksson PO, Rask-Andersen H, Liu W, Laurell G. The Acute Effects of Furosemide on Na-K-Cl Cotransporter-1, Fetuin-A and Pigment Epithelium-Derived Factor in the Guinea Pig Cochlea. Front Mol Neurosci 2022; 15:842132. [PMID: 35392272 PMCID: PMC8981210 DOI: 10.3389/fnmol.2022.842132] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/22/2022] [Indexed: 11/28/2022] Open
Abstract
Background Furosemide is a loop diuretic used to treat edema; however, it also targets the Na-K-Cl cotransporter-1 (NKCC1) in the inner ear. In very high doses, furosemide abolishes the endocochlear potential (EP). The aim of the study was to gain a deeper understanding of the temporal course of the acute effects of furosemide in the inner ear, including the protein localization of Fetuin-A and PEDF in guinea pig cochleae. Material and Method Adult guinea pigs were given an intravenous injection of furosemide in a dose of 100 mg per kg of body weight. The cochleae were studied using immunohistochemistry in controls and at four intervals: 3 min, 30 min, 60 min and 120 min. Also, cochleae of untreated guinea pigs were tested for Fetuin-A and PEDF mRNA using RNAscope® technology. Results At 3 min, NKCC1 staining was abolished in the type II fibrocytes in the spiral ligament, followed by a recovery period of up to 120 min. In the stria vascularis, the lowest staining intensity of NKCC1 presented after 30 min. The spiral ganglion showed a stable staining intensity for the full 120 min. Fetuin-A protein and mRNA were detected in the spiral ganglion type I neurons, inner and outer hair cells, pillar cells, Deiters cells and the stria vascularis. Furosemide induced an increased staining intensity of Fetuin-A at 120 min. PEDF protein and mRNA were found in the spiral ganglia type I neurons, the stria vascularis, and in type I and type II fibrocytes of the spiral ligament. PEDF protein staining intensity was high in the pillar cells in the organ of Corti. Furosemide induced an increased staining intensity of PEDF in type I neurons and pillar cells after 120 min. Conclusion The results indicate rapid furosemide-induced changes of NKCC1 in the type II fibrocytes. This could be part of the mechanism that causes reduction of the EP within minutes after high dose furosemide injection. Fetuin-A and PEDF are present in many cells of the cochlea and probably increase after furosemide exposure, possibly as an otoprotective response.
Collapse
|
15
|
Noble K, Brown L, Elvis P, Lang H. Cochlear Immune Response in Presbyacusis: a Focus on Dysregulation of Macrophage Activity. J Assoc Res Otolaryngol 2022; 23:1-16. [PMID: 34642854 PMCID: PMC8782976 DOI: 10.1007/s10162-021-00819-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/25/2021] [Indexed: 02/03/2023] Open
Abstract
Age-related hearing loss, or presbyacusis, is a prominent chronic degenerative disorder that affects many older people. Based on presbyacusis pathology, the degeneration occurs in both sensory and non-sensory cells, along with changes in the cochlear microenvironment. The progression of age-related neurodegenerative diseases is associated with an altered microenvironment that reflects chronic inflammatory signaling. Under these conditions, resident and recruited immune cells, such as microglia/macrophages, have aberrant activity that contributes to chronic neuroinflammation and neural cell degeneration. Recently, researchers identified and characterized macrophages in human cochleae (including those from older donors). Along with the age-related changes in cochlear macrophages in animal models, these studies revealed that macrophages, an underappreciated group of immune cells, may play a critical role in maintaining the functional integrity of the cochlea. Although several studies deciphered the molecular mechanisms that regulate microglia/macrophage dysfunction in multiple neurodegenerative diseases, limited studies have assessed the mechanisms underlying macrophage dysfunction in aged cochleae. In this review, we highlight the age-related changes in cochlear macrophage activities in mouse and human temporal bones. We focus on how complement dysregulation and the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 inflammasome could affect macrophage activity in the aged peripheral auditory system. By understanding the molecular mechanisms that underlie these regulatory systems, we may uncover therapeutic strategies to treat presbyacusis and other forms of sensorineural hearing loss.
Collapse
Affiliation(s)
- Kenyaria Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Akouos, Inc, Boston, MA, 02210, USA
| | - LaShardai Brown
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Biology, Winthrop University, Rock Hill, SD, 29733, USA
| | - Phillip Elvis
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA.
| |
Collapse
|
16
|
Spankovich C, Walters BJ. Mild Therapeutic Hypothermia and Putative Mechanisms of Hair Cell Survival in the Cochlea. Antioxid Redox Signal 2021; 36:1203-1214. [PMID: 34619988 PMCID: PMC9221161 DOI: 10.1089/ars.2021.0184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 12/20/2022]
Abstract
Significance: Sensorineural hearing loss has significant implications for quality of life and risk for comorbidities such as cognitive decline. Noise and ototoxic drugs represent two common risk factors for acquired hearing loss that are potentially preventable. Recent Advances: Numerous otoprotection strategies have been postulated over the past four decades with primary targets of upstream redox pathways. More recently, the application of mild therapeutic hypothermia (TH) has shown promise for otoprotection for multiple forms of acquired hearing loss. Critical Issues: Systemic antioxidant therapy may have limited application for certain ototoxic drugs with a therapeutic effect on redox pathways and diminished efficacy of the primary drug's therapeutic function (e.g., cisplatin for tumors). Future Directions: Mild TH likely targets multiple mechanisms, contributing to otoprotection, including slowed metabolics, reduced oxidative stress, and involvement of cold shock proteins. Further work is needed to identify the mechanisms of mild TH at play for various forms of acquired hearing loss.
Collapse
Affiliation(s)
- Christopher Spankovich
- Department of Otolaryngology-Head and Neck Surgery and University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Bradley J. Walters
- Department of Otolaryngology-Head and Neck Surgery and University of Mississippi Medical Center, Jackson, Mississippi, USA
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi, USA
| |
Collapse
|
17
|
Yu C, Gao HM, Wan G. Macrophages Are Dispensable for Postnatal Pruning of the Cochlear Ribbon Synapses. Front Cell Neurosci 2021; 15:736120. [PMID: 34744631 PMCID: PMC8566810 DOI: 10.3389/fncel.2021.736120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/05/2021] [Indexed: 11/15/2022] Open
Abstract
Ribbon synapses of cochlear hair cells undergo pruning and maturation before the hearing onset. In the central nervous system (CNS), synaptic pruning was mediated by microglia, the brain-resident macrophages, via activation of the complement system. Whether a similar mechanism regulates ribbon synapse pruning is currently unknown. In this study, we report that the densities of cochlear macrophages surrounding hair cells were highest at around P8, corresponding well to the completion of ribbon synaptic pruning by P8–P9. Surprisingly, using multiple genetic mouse models, we found that postnatal pruning of the ribbon synapses and auditory functions were unaffected by the knockout of the complement receptor 3 (CR3) or by ablations of macrophages expressing either LysM or Cx3cr1. Our results suggest that unlike microglia in the CNS, macrophages in the cochlea do not mediate pruning of the cochlear ribbon synapses.
Collapse
Affiliation(s)
- Chaorong Yu
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing, China.,Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China
| | - Hui-Ming Gao
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing, China.,Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Guoqiang Wan
- MOE Key Laboratory of Model Animal for Disease Study, Department of Otorhinolaryngology-Head and Neck Surgery, The Affiliated Drum Tower Hospital of Medical School, Model Animal Research Center of Medical School, Nanjing University, Nanjing, China.,Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China.,Research Institute of Otolaryngology, Nanjing, China
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Milinkeviciute G, Chokr SM, Castro EM, Cramer KS. CX3CR1 mutation alters synaptic and astrocytic protein expression, topographic gradients, and response latencies in the auditory brainstem. J Comp Neurol 2021; 529:3076-3097. [PMID: 33797066 DOI: 10.1002/cne.25150] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 03/04/2021] [Accepted: 03/27/2021] [Indexed: 01/14/2023]
Abstract
The precise and specialized circuitry in the auditory brainstem develops through adaptations of cellular and molecular signaling. We previously showed that elimination of microglia during development impairs synaptic pruning that leads to maturation of the calyx of Held, a large encapsulating synapse that terminates on neurons of the medial nucleus of the trapezoid body (MNTB). Microglia depletion also led to a decrease in glial fibrillary acidic protein (GFAP), a marker for mature astrocytes. Here, we investigated the role of signaling through the fractalkine receptor (CX3CR1), which is expressed by microglia and mediates communication with neurons. CX3CR1-/- and wild-type mice were studied before and after hearing onset and at 9 weeks of age. Levels of GFAP were significantly increased in the MNTB in mutants at 9 weeks. Pruning was unaffected at the calyx of Held, but we found an increase in expression of glycinergic synaptic marker in mutant mice at P14, suggesting an effect on maturation of inhibitory inputs. We observed disrupted tonotopic gradients of neuron and calyx size in MNTB in mutant mice. Auditory brainstem recording (ABR) revealed that CX3CR1-/- mice had normal thresholds and amplitudes but decreased latencies and interpeak latencies, particularly for the highest frequencies. These results demonstrate that disruption of fractalkine signaling has a significant effect on auditory brainstem development. Our findings highlight the importance of neuron-microglia-astrocyte communication in pruning of inhibitory synapses and establishment of tonotopic gradients early in postnatal development.
Collapse
Affiliation(s)
- Giedre Milinkeviciute
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Sima M Chokr
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Emily M Castro
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| | - Karina S Cramer
- Department of Neurobiology and Behavior, University of California, Irvine, California, USA
| |
Collapse
|
22
|
Liu Z, Bai X, Wan P, Mo F, Chen G, Zhang J, Gao J. Targeted Deletion of Loxl3 by Col2a1-Cre Leads to Progressive Hearing Loss. Front Cell Dev Biol 2021; 9:683495. [PMID: 34150778 PMCID: PMC8212933 DOI: 10.3389/fcell.2021.683495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 05/11/2021] [Indexed: 12/20/2022] Open
Abstract
Collagens are major constituents of the extracellular matrix (ECM) that play an essential role in the structure of the inner ear and provide elasticity and rigidity when the signals of sound are received and transformed into electrical signals. LOXL3 is a member of the lysyl oxidase (LOX) family that are copper-dependent amine oxidases, generating covalent cross-links to stabilize polymeric elastin and collagen fibers in the ECM. Biallelic missense variant of LOXL3 was found in Stickler syndrome with mild conductive hearing loss. However, available information regarding the specific roles of LOXL3 in auditory function is limited. In this study, we showed that the Col2a1-Cre-mediated ablation of Loxl3 in the inner ear can cause progressive hearing loss, degeneration of hair cells and secondary degeneration of spiral ganglion neurons. The abnormal distribution of type II collagen in the spiral ligament and increased inflammatory responses were also found in Col2a1–Loxl3–/– mice. Amino oxidase activity exerts an effect on collagen; thus, Loxl3 deficiency was expected to result in the instability of collagen in the spiral ligament and the basilar membrane, which may interfere with the mechanical properties of the organ of Corti and induce the inflammatory responses that are responsible for the hearing loss. Overall, our findings suggest that Loxl3 may play an essential role in maintaining hearing function.
Collapse
Affiliation(s)
- Ziyi Liu
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Xinfeng Bai
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Peifeng Wan
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Fan Mo
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Ge Chen
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Jian Zhang
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| | - Jiangang Gao
- School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan, China
| |
Collapse
|
23
|
Eckert MA, Harris KC, Lang H, Lewis MA, Schmiedt RA, Schulte BA, Steel KP, Vaden KI, Dubno JR. Translational and interdisciplinary insights into presbyacusis: A multidimensional disease. Hear Res 2021; 402:108109. [PMID: 33189490 PMCID: PMC7927149 DOI: 10.1016/j.heares.2020.108109] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 12/18/2022]
Abstract
There are multiple etiologies and phenotypes of age-related hearing loss or presbyacusis. In this review we summarize findings from animal and human studies of presbyacusis, including those that provide the theoretical framework for distinct metabolic, sensory, and neural presbyacusis phenotypes. A key finding in quiet-aged animals is a decline in the endocochlear potential (EP) that results in elevated pure-tone thresholds across frequencies with greater losses at higher frequencies. In contrast, sensory presbyacusis appears to derive, in part, from acute and cumulative effects on hair cells of a lifetime of environmental exposures (e.g., noise), which often result in pronounced high frequency hearing loss. These patterns of hearing loss in animals are recognizable in the human audiogram and can be classified into metabolic and sensory presbyacusis phenotypes, as well as a mixed metabolic+sensory phenotype. However, the audiogram does not fully characterize age-related changes in auditory function. Along with the effects of peripheral auditory system declines on the auditory nerve, primary degeneration in the spiral ganglion also appears to contribute to central auditory system aging. These inner ear alterations often correlate with structural and functional changes throughout the central nervous system and may explain suprathreshold speech communication difficulties in older adults with hearing loss. Throughout this review we highlight potential methods and research directions, with the goal of advancing our understanding, prevention, diagnosis, and treatment of presbyacusis.
Collapse
Affiliation(s)
- Mark A Eckert
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA.
| | - Kelly C Harris
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Hainan Lang
- Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA
| | - Morag A Lewis
- King's College London, Wolfson Centre for Age-Related Diseases, London SE1 1UL, United Kingdom
| | - Richard A Schmiedt
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Bradley A Schulte
- Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA; Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Karen P Steel
- King's College London, Wolfson Centre for Age-Related Diseases, London SE1 1UL, United Kingdom
| | - Kenneth I Vaden
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA
| | - Judy R Dubno
- Medical University of South Carolina, Department of Otolaryngology - Head and Neck Surgery, Charleston, SC 29425, USA; Medical University of South Carolina, Department of Pathology and Laboratory Medicine, Charleston, SC 29425, USA
| |
Collapse
|
24
|
Xu K, Chen S, Xie L, Qiu Y, Bai X, Liu XZ, Zhang HM, Wang XH, Jin Y, Sun Y, Kong WJ. Local Macrophage-Related Immune Response Is Involved in Cochlear Epithelial Damage in Distinct Gjb2-Related Hereditary Deafness Models. Front Cell Dev Biol 2021; 8:597769. [PMID: 33505961 PMCID: PMC7829512 DOI: 10.3389/fcell.2020.597769] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
The macrophage-related immune response is an important component of the cochlear response to different exogenous stresses, including noise, ototoxic antibiotics, toxins, or viral infection. However, the role of the immune response in hereditary deafness caused by genetic mutations is rarely explored. GJB2, encoding connexin 26 (Cx26), is the most common deafness gene of hereditary deafness. In this study, two distinct Cx26-null mouse models were established to investigate the types and underlying mechanisms of immune responses. In a systemic Cx26-null model, macrophage recruitment was observed, associated with extensive cell degeneration of the cochlear epithelium. In a targeted-cell Cx26-null model, knockout of Cx26 was restricted to specific supporting cells (SCs), which led to preferential loss of local outer hair cells (OHCs). This local OHC loss can also induce a macrophage-related immune response. Common inflammatory factors, including TNF-α, IL-1β, Icam-1, Mif, Cx3cr1, Tlr4, Ccl2, and Ccr2, did not change significantly, while mRNA of Cx3cl1 was upregulated. Quantitative immunofluorescence showed that the protein expression of CX3CL1 in Deiters cells, a type of SC coupled with OHCs, increased significantly after OHC death. OHC loss caused the secondary death of spiral ganglion neurons (SGNs), while the remaining SGNs expressed high levels of CX3CL1 with infiltrated macrophages. Taken together, our results indicate that CX3CL1 signaling regulates macrophage recruitment and that enhancement of macrophage antigen-presenting function is associated with cell degeneration in Cx26-null mice.
Collapse
Affiliation(s)
- Kai Xu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sen Chen
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Le Xie
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Qiu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xue Bai
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Zhou Liu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui-Min Zhang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Hui Wang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuan Jin
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei-Jia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Tongji Medical College, Institute of Otorhinolaryngology, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
25
|
Warchol ME, Schrader A, Sheets L. Macrophages Respond Rapidly to Ototoxic Injury of Lateral Line Hair Cells but Are Not Required for Hair Cell Regeneration. Front Cell Neurosci 2021; 14:613246. [PMID: 33488362 PMCID: PMC7820375 DOI: 10.3389/fncel.2020.613246] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/03/2020] [Indexed: 01/01/2023] Open
Abstract
The sensory organs of the inner ear contain resident populations of macrophages, which are recruited to sites of cellular injury. Such macrophages are known to phagocytose the debris of dying cells but the full role of macrophages in otic pathology is not understood. Lateral line neuromasts of zebrafish contain hair cells that are nearly identical to those in the inner ear, and the optical clarity of larval zebrafish permits direct imaging of cellular interactions. In this study, we used larval zebrafish to characterize the response of macrophages to ototoxic injury of lateral line hair cells. Macrophages migrated into neuromasts within 20 min of exposure to the ototoxic antibiotic neomycin. The number of macrophages in the near vicinity of injured neuromasts was similar to that observed near uninjured neuromasts, suggesting that this early inflammatory response was mediated by "local" macrophages. Upon entering injured neuromasts, macrophages actively phagocytosed hair cell debris. The injury-evoked migration of macrophages was significantly reduced by inhibition of Src-family kinases. Using chemical-genetic ablation of macrophages before the ototoxic injury, we also examined whether macrophages were essential for the initiation of hair cell regeneration. Results revealed only minor differences in hair cell recovery in macrophage-depleted vs. control fish, suggesting that macrophages are not essential for the regeneration of lateral line hair cells.
Collapse
Affiliation(s)
- Mark E. Warchol
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Angela Schrader
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
| | - Lavinia Sheets
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
26
|
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.
Collapse
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
Collapse
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.
| |
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
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.
Collapse
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.
| |
Collapse
|
29
|
He W, Yu J, Sun Y, Kong W. Macrophages in Noise-Exposed Cochlea: Changes, Regulation and the Potential Role. Aging Dis 2020; 11:191-199. [PMID: 32010492 PMCID: PMC6961779 DOI: 10.14336/ad.2019.0723] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022] Open
Abstract
Acoustic trauma is an important physical factor leading to cochlear damage and hearing impairments. Inflammation responds to this kind of cochlear damage stress. Macrophages, the major innate immune cells in the cochlea, are important drivers of inflammatory and tissue repair responses after cochlear injury. Recently, studies have shown that after noise exposure, the distribution, phenotype, and the number of cochlear macrophages have significantly changed, and the local environmental factors that shape macrophage differentiation and behavior are also drastically altered. However, the exact role of these immune cells in the cochlea after acoustic injury remains unknown. Here we review the properties of cochlear macrophages both under steady-state conditions and non-homeostatic conditions after cochlear acoustic injury and discuss their potential role in noise-exposed cochlea.
Collapse
Affiliation(s)
- Weiwei He
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jintao Yu
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Yu Sun
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Weijia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| |
Collapse
|
30
|
The TLR-4/NF-κB signaling pathway activation in cochlear inflammation of rats with noise-induced hearing loss. Hear Res 2019; 379:59-68. [DOI: 10.1016/j.heares.2019.04.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 04/13/2019] [Accepted: 04/23/2019] [Indexed: 01/18/2023]
|
31
|
Köles L, Szepesy J, Berekméri E, Zelles T. Purinergic Signaling and Cochlear Injury-Targeting the Immune System? Int J Mol Sci 2019; 20:ijms20122979. [PMID: 31216722 PMCID: PMC6627352 DOI: 10.3390/ijms20122979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/14/2019] [Accepted: 06/14/2019] [Indexed: 02/06/2023] Open
Abstract
Hearing impairment is the most common sensory deficit, affecting more than 400 million people worldwide. Sensorineural hearing losses currently lack any specific or efficient pharmacotherapy largely due to the insufficient knowledge of the pathomechanism. Purinergic signaling plays a substantial role in cochlear (patho)physiology. P2 (ionotropic P2X and the metabotropic P2Y) as well as adenosine receptors expressed on cochlear sensory and non-sensory cells are involved mostly in protective mechanisms of the cochlea. They are implicated in the sensitivity adjustment of the receptor cells by a K+ shunt and can attenuate the cochlear amplification by modifying cochlear micromechanics. Cochlear blood flow is also regulated by purines. Here, we propose to comprehend this field with the purine-immune interactions in the cochlea. The role of harmful immune mechanisms in sensorineural hearing losses has been emerging in the horizon of cochlear pathologies. In addition to decreasing hearing sensitivity and increasing cochlear blood supply, influencing the immune system can be the additional avenue for pharmacological targeting of purinergic signaling in the cochlea. Elucidating this complexity of purinergic effects on cochlear functions is necessary and it can result in development of new therapeutic approaches in hearing disabilities, especially in the noise-induced ones.
Collapse
Affiliation(s)
- László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Judit Szepesy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
| | - Eszter Berekméri
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Ecology, University of Veterinary Medicine, H-1078 Budapest, Hungary.
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, H-1089 Budapest, Hungary.
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, H-1083 Budapest, Hungary.
| |
Collapse
|
32
|
Kaur T, Clayman AC, Nash AJ, Schrader AD, Warchol ME, Ohlemiller KK. Lack of Fractalkine Receptor on Macrophages Impairs Spontaneous Recovery of Ribbon Synapses After Moderate Noise Trauma in C57BL/6 Mice. Front Neurosci 2019; 13:620. [PMID: 31263398 PMCID: PMC6585312 DOI: 10.3389/fnins.2019.00620] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/29/2019] [Indexed: 01/08/2023] Open
Abstract
Noise trauma causes loss of synaptic connections between cochlear inner hair cells (IHCs) and the spiral ganglion neurons (SGNs). Such synaptic loss can trigger slow and progressive degeneration of SGNs. Macrophage fractalkine signaling is critical for neuron survival in the injured cochlea, but its role in cochlear synaptopathy is unknown. Fractalkine, a chemokine, is constitutively expressed by SGNs and signals via its receptor CX3CR1 that is expressed on macrophages. The present study characterized the immune response and examined the function of fractalkine signaling in degeneration and repair of cochlear synapses following noise trauma. Adult mice wild type, heterozygous and knockout for CX3CR1 on a C57BL/6 background were exposed for 2 h to an octave band noise at 90 dB SPL. Noise exposure caused temporary shifts in hearing thresholds without any evident loss of hair cells in CX3CR1 heterozygous mice that have intact fractalkine signaling. Enhanced macrophage migration toward the IHC-synaptic region was observed immediately after exposure in all genotypes. Synaptic immunolabeling revealed a rapid loss of ribbon synapses throughout the basal turn of the cochlea of all genotypes. The damaged synapses spontaneously recovered in mice with intact CX3CR1. However, CX3CR1 knockout (KO) animals displayed enhanced synaptic degeneration that correlated with attenuated suprathreshold neural responses at higher frequencies. Exposed CX3CR1 KO mice also exhibited increased loss of IHCs and SGN cell bodies compared to exposed heterozygous mice. These results indicate that macrophages can promote repair of damaged synapses after moderate noise trauma and that repair requires fractalkine signaling.
Collapse
Affiliation(s)
- Tejbeer Kaur
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
| | - Anna C Clayman
- Program in Audiology and Communication Sciences, Washington University School of Medicine, St. Louis, MO, United States
| | - Andrew J Nash
- Program in Audiology and Communication Sciences, Washington University School of Medicine, St. Louis, MO, United States
| | - Angela D Schrader
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
| | - Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States
| | - Kevin K Ohlemiller
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO, United States.,Program in Audiology and Communication Sciences, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
33
|
Warchol ME. Interactions between Macrophages and the Sensory Cells of the Inner Ear. Cold Spring Harb Perspect Med 2019; 9:cshperspect.a033555. [PMID: 30181352 DOI: 10.1101/cshperspect.a033555] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Macrophages are present in most somatic tissues, where they detect and attack invading pathogens. Macrophages also participate in many nonimmune functions, particularly those related to tissue maintenance and injury response. The sensory organs of the inner ear contain resident populations of macrophages, and additional macrophages enter the ear after acoustic trauma or ototoxicity. As expected, such macrophages participate in the clearance of cellular debris. However, otic macrophages can also influence the long-term survival of both hair cells and afferent neurons after injury. The signals that recruit macrophages into the injured ear, as well as the precise contributions of macrophages to inner ear pathology, remain to be determined.
Collapse
Affiliation(s)
- Mark E Warchol
- Department of Otolaryngology, Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri 63110
| |
Collapse
|
34
|
Coate TM, Scott MK, Gurjar MC. Current concepts in cochlear ribbon synapse formation. Synapse 2019; 73:e22087. [PMID: 30592086 PMCID: PMC6573016 DOI: 10.1002/syn.22087] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022]
Abstract
In mammals, hair cells and spiral ganglion neurons (SGNs) in the cochlea together are sophisticated "sensorineural" structures that transduce auditory information from the outside world into the brain. Hair cells and SGNs are joined by glutamatergic ribbon-type synapses composed of a molecular machinery rivaling in complexity the mechanoelectric transduction components found at the apical side of the hair cell. The cochlear hair cell ribbon synapse has received much attention lately because of recent and important findings related to its damage (sometimes termed "synaptopathy") as a result of noise overexposure. During development, ribbon synapses between type I SGNs and inner hair cells form in the time window between birth and hearing onset and is a process coordinated with type I SGN myelination, spontaneous activity, synaptic pruning, and innervation by efferents. In this review, we highlight new findings regarding the diversity of type I SGNs and inner hair cell synapses, and the molecular mechanisms of selective hair cell targeting. Also discussed are cell adhesion molecules and protein constituents of the ribbon synapse, and how these factors participate in ribbon synapse formation. We also note interesting new insights into the morphological development of type II SGNs, and the potential for cochlear macrophages as important players in protecting SGNs. We also address recent studies demonstrating that the structural and physiological profiles of the type I SGNs do not reach full maturity until weeks after hearing onset, suggesting a protracted development that is likely modulated by activity.
Collapse
Affiliation(s)
- Thomas M. Coate
- Georgetown University, Department of Biology, 37th and O St. NW. Washington, DC. 20007. USA
| | - M. Katie Scott
- Department of Biological Sciences and Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, Indiana 47907. USA
| | - Mansa C. Gurjar
- Georgetown University, Department of Biology, 37th and O St. NW. Washington, DC. 20007. USA
| |
Collapse
|
35
|
Necroptosis and Apoptosis Contribute to Cisplatin and Aminoglycoside Ototoxicity. J Neurosci 2019; 39:2951-2964. [PMID: 30733218 DOI: 10.1523/jneurosci.1384-18.2019] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 11/21/2022] Open
Abstract
Ototoxic side effects of cisplatin and aminoglycosides have been extensively studied, but no therapy is available to date. Sensory hair cells, upon exposure to cisplatin or aminoglycosides, undergo apoptotic and necrotic cell death. Blocking these cell death pathways has therapeutic potential in theory, but incomplete protection and lack of therapeutic targets in the case of necrosis, has hampered the development of clinically applicable drugs. Over the past decade, a novel form of necrosis, termed necroptosis, was established as an alternative cell death pathway. Necroptosis is distinguished from passive necrotic cell death, in that it follows a cellular program, involving the receptor-interacting protein kinase (RIPK) 1 and RIPK3. In this study, we used pharmacological and genetic interventions in the mouse to test the relative contributions of necroptosis and caspase-8-mediated apoptosis toward cisplatin and aminoglycoside ototoxicity. We find that ex vivo, only apoptosis contributes to cisplatin and aminoglycoside ototoxicity, while in vivo, necroptosis as well as apoptosis are involved in both sexes. Inhibition of necroptosis and apoptosis using pharmacological compounds is thus a viable strategy to ameliorate aminoglycoside and cisplatin ototoxicity.SIGNIFICANCE STATEMENT The clinical application of cisplatin and aminoglycosides is limited due to ototoxic side effects. Here, using pharmaceutical and genetic intervention, we present evidence that two types of programmed cell death, apoptosis and necroptosis, contribute to aminoglycoside and cisplatin ototoxicity. Key molecular factors mediating necroptosis are well characterized and druggable, presenting new avenues for pharmaceutical intervention.
Collapse
|
36
|
Microvascular networks in the area of the auditory peripheral nervous system. Hear Res 2019; 371:105-116. [DOI: 10.1016/j.heares.2018.11.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/14/2018] [Accepted: 11/28/2018] [Indexed: 12/20/2022]
|
37
|
Wang A, Yang T, Zhang L, Jia L, Wu Q, Yao S, Xu J, Yang H. IP3-Mediated Calcium Signaling Is Involved in the Mechanism of Fractalkine-Induced Hyperalgesia Response. Med Sci Monit 2018; 24:8804-8811. [PMID: 30517088 PMCID: PMC6290586 DOI: 10.12659/msm.913787] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Fractalkine is widely expressed throughout the brain and spinal cord, where it can exert effects on pain enhancement and hyperalgesia by activating microglia through CX3C chemokine receptor 1 (CX3CR1), which triggers the release of several pro-inflammatory cytokines in the spinal cord. Fractalkine has also been shown to increase cytosolic calcium ([Ca2+]i) in microglia. Material/Methods Based on the characteristics of CX3CR1, a G protein-coupled receptor, we explored the role of inositol 1,4,5-trisphosphate (IP3) signaling in fractalkine-induced inflammatory response in BV-2 cells in vitro. The effect and the underlying mechanism induced by fractalkine in the brain were observed using a mouse model with intracerebroventricular (i.c.v.) injection of exogenous fractalkine. Results [Ca2+]i was significantly increased and IL-1β and TNF-α levels were higher in the fractalkine-treated cell groups than in the farctalkine+ 2-APB groups. We found that i.c.v. injection of fractalkine significantly increased p-p38MAPK, IL-1β, and TNF-α expression in the brain, while i.c.v. injection of a fractalkine-neutralizing antibody (anti-CX3CR1), trisphosphate receptor (IP3R) antagonist (2-APB), or p38MAPK inhibitor (SB203580) prior to fractalkine addition yielded an effective and reliable anti-allodynia effect, following the reduction of p-p38MAPK, IL-1β, and TNF-α expression. Conclusions Our results suggest that fractalkine leads to hyperalgesia, and the underlying mechanism may be associated with IP3/p38MAPK-mediated calcium signaling and its phlogogenic properties.
Collapse
Affiliation(s)
- Aitao Wang
- Department of Anesthesiology, Inner Mongolia Autonomous Region People's Hospital, Hohhot, Inner Mongolia, China (mainland)
| | - Tingting Yang
- Key Laboratory of Antibody Technique of National Health and Family Planning Commission, Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Lingli Zhang
- Department of Ophthalmology, Inner Mongolia Autonomous Region People's Hospital, Hohhot, Inner Mongolia, China (mainland)
| | - Lizhou Jia
- Key Laboratory of Antibody Technique of National Health and Family Planning Commission, Nanjing Medical University, Nanjing, Jiangsu, China (mainland)
| | - Qingping Wu
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland)
| | - Shanglong Yao
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland)
| | - Jianjun Xu
- Department of Anesthesiology, General Hospital of Daqing Oil Field, Daqing, Heilongjiang, China (mainland)
| | - Hongxin Yang
- Department of Pharmacy, Inner Mongolia Autonomous Region People's Hospital, Hohhot, Inner Mongolia, China (mainland)
| |
Collapse
|