1
|
Jain A, Perdomo D, Nagururu N, Li JA, Ward BK, Lauer AM, Creighton FX. SVPath: A Deep Learning Tool for Analysis of Stria Vascularis from Histology Slides. J Assoc Res Otolaryngol 2024:10.1007/s10162-024-00948-z. [PMID: 38760547 DOI: 10.1007/s10162-024-00948-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 04/18/2024] [Indexed: 05/19/2024] Open
Abstract
INTRODUCTION The stria vascularis (SV) may have a significant role in various otologic pathologies. Currently, researchers manually segment and analyze the stria vascularis to measure structural atrophy. Our group developed a tool, SVPath, that uses deep learning to extract and analyze the stria vascularis and its associated capillary bed from whole temporal bone histopathology slides (TBS). METHODS This study used an internal dataset of 203 digitized hematoxylin and eosin-stained sections from a normal macaque ear and a separate external validation set of 10 sections from another normal macaque ear. SVPath employed deep learning methods YOLOv8 and nnUnet to detect and segment the SV features from TBS, respectively. The results from this process were analyzed with the SV Analysis Tool (SVAT) to measure SV capillaries and features related to SV morphology, including width, area, and cell count. Once the model was developed, both YOLOv8 and nnUnet were validated on external and internal datasets. RESULTS YOLOv8 implementation achieved over 90% accuracy for cochlea and SV detection. nnUnet SV segmentation achieved a DICE score of 0.84-0.95; the capillary bed DICE score was 0.75-0.88. SVAT was applied to compare both the ears used in the study. There was no statistical difference in SV width, SV area, and average area of capillary between the two ears. There was a statistical difference between the two ears for the cell count per SV. CONCLUSION The proposed method accurately and efficiently analyzes the SV from temporal histopathology bone slides, creating a platform for researchers to understand the function of the SV further.
Collapse
Affiliation(s)
- Aseem Jain
- College of Medicine, University of Cincinnati, 231 Albert Sabin Way, Cincinnati, OH, 45267, USA.
| | - Dianela Perdomo
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nimesh Nagururu
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jintong Alice Li
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bryan K Ward
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Amanda M Lauer
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Francis X Creighton
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
2
|
Gu X, Jiang K, Chen R, Chen Z, Wu X, Xiang H, Huang X, Nan B. Identification of common stria vascularis cellular alteration in sensorineural hearing loss based on ScRNA-seq. BMC Genomics 2024; 25:213. [PMID: 38413848 PMCID: PMC10897997 DOI: 10.1186/s12864-024-10122-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/14/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND The stria vascularis (SV), located in the lateral wall of the cochlea, maintains cochlear fluid homeostasis and mechanoelectrical transduction (MET) activity required for sound wave conduction. The pathogenesis of a number of human inheritable deafness syndromes, age related hearing loss, drug-induced ototoxicity and noise-induced hearing loss results from the morphological changes and functional impairments in the development of the SV. In this study, we investigate the implications of intercellular communication within the SV in the pathogenesis of sensorineural hearing loss (SNHL). We aim to identify commonly regulated signaling pathways using publicly available single-cell transcriptomic sequencing (scRNA-seq) datasets. METHODS We analyzed scRNA-seq data, which was derived from studying the cochlear SV in mice with SNHL compared to normal adult mice. After quality control and filtering, we obtained the major cellular components of the mouse cochlear SV and integrated the data. Using Seurat's FindAllMarkers and FindMarkers packages, we searched for novel conservative genes and differential genes. We employed KEGG and GSEA to identify molecular pathways that are commonly altered among different types of SNHL. We utilized pySCENIC to discover new specific regulatory factors in SV subpopulation cells. With the help of CellChat, we identified changes in subpopulation cells showing similar trends across different SNHL types and their alterations in intercellular communication pathways. RESULTS Through the analysis of the integrated data, we discovered new conserved genes to SV specific cells and identified common downregulated pathways in three types of SNHL. The enriched genes for these pathways showing similar trends are primarily associated with the Electron Transport Chain, related to mitochondrial energy metabolism. Using the CellChat package, we further found that there are shared pathways in the incoming signaling of specific intermediate cells in SNHL, and these pathways have common upstream regulatory transcription factor of Nfe2l2. Combining the results from pySCENIC and CellChat, we predicted the transcription factor Nfe2l2 as an upstream regulatory factor for multiple shared cellular pathways in IC. Additionally, it serves as an upstream factor for several genes within the Electron Transport Chain. CONCLUSION Our bioinformatics analysis has revealed that downregulation of the mitochondrial electron transport chain have been observed in various conditions of SNHL. E2f1, Esrrb, Runx1, Yy1, and Gata2 could serve as novel important common TFs regulating the electron transport chain. Adm has emerged as a potential new marker gene for intermediate cells, while Itgb5 and Tesc show promise as potential new marker genes for marginal cells in the SV. These findings offer a new perspective on SV lesions in SNHL and provide additional theoretical evidence for the same drug treatment and prevention of different pathologies of SNHL.
Collapse
Affiliation(s)
- Xi Gu
- Department of Otorhinolaryngology, Head and Neck Surgery, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- Fujian Institute of Otolaryngology, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- Department of Otorhinolaryngology, Head and Neck Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Kanglun Jiang
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongshan Hospital, Fudan University, Fenglin Road 180, Xuhui District, Shanghai, 200030, People's Republic of China
| | - Ruru Chen
- Department of Otorhinolaryngology, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhifeng Chen
- Department of Otorhinolaryngology, Head and Neck Surgery, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- Fujian Institute of Otolaryngology, the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
- Department of Otorhinolaryngology, Head and Neck Surgery, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, China
| | - Xianmin Wu
- Department of Otolaryngology-Head and Neck Surgery, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Haijie Xiang
- Department of Otorhinolaryngology, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xinsheng Huang
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongshan Hospital, Fudan University, Fenglin Road 180, Xuhui District, Shanghai, 200030, People's Republic of China.
| | - Benyu Nan
- Department of Otorhinolaryngology, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| |
Collapse
|
3
|
Singh S, Maheshwari A, Boppana S. CMV-induced Hearing Loss. Newborn (Clarksville) 2023; 2:249-262. [PMID: 38348106 PMCID: PMC10860330 DOI: 10.5005/jp-journals-11002-0081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
Congenital cytomegalovirus (cCMV) infection is the most common fetal viral infection and contributes to about 25% of childhood hearing loss by the age of 4 years. It is the leading nongenetic cause of sensorineural hearing loss (SNHL). Infants born to seroimmune mothers are not completely protected from SNHL, although the severity of their hearing loss may be milder than that seen in those whose mothers had a primary infection. Both direct cytopathic effects and localized inflammatory responses contribute to the pathogenesis of cytomegalovirus (CMV)-induced hearing loss. Hearing loss may be delayed onset, progressive or fluctuating in nature, and therefore, a significant proportion will be missed by universal newborn hearing screening (NHS) and warrants close monitoring of hearing function at least until 5-6 years of age. A multidisciplinary approach is required for the management of hearing loss. These children may need assistive hearing devices or cochlear implantation depending on the severity of their hearing loss. In addition, early intervention services such as speech or occupational therapy could help better communication, language, and social skill outcomes. Preventive measures to decrease intrauterine CMV transmission that have been evaluated include personal protective measures, passive immunoprophylaxis and valacyclovir treatment during pregnancy in mothers with primary CMV infection. Several vaccine candidates are currently in testing and one candidate vaccine in phase 3 trials. Until a CMV vaccine becomes available, behavioral and educational interventions may be the most effective strategy to prevent maternal CMV infection.
Collapse
Affiliation(s)
- Srijan Singh
- Department of Neonatology, Kailash Hospital, Noida, Uttar Pradesh, India
- Global Newborn Society (https://www.globalnewbornsociety.org/), Clarksville, Maryland, United States of America
| | - Akhil Maheshwari
- Global Newborn Society (https://www.globalnewbornsociety.org/), Clarksville, Maryland, United States of America
- Department of Pediatrics, Louisiana State University, Shreveport, Louisiana, United States of America
| | - Suresh Boppana
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| |
Collapse
|
4
|
Peng Z, Zhao C, Yang Z, Gong S, Du Z. D-galactose-induced mitochondrial oxidative damage and apoptosis in the cochlear stria vascularis of mice. BMC Mol Cell Biol 2023; 24:27. [PMID: 37605129 PMCID: PMC10441755 DOI: 10.1186/s12860-023-00480-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/02/2023] [Indexed: 08/23/2023] Open
Abstract
BACKGROUND Age-related hearing loss, known as presbycusis, is the result of auditory system degeneration. Numerous studies have suggested that reactive oxygen species (ROS) and mitochondrial oxidative damage play important roles in the occurrence and progression of aging. The D-galactose (D-gal)-induced aging model is well known and widely utilized in aging research. Our previous studies demonstrate that administration of D-gal causes mitochondrial oxidative damage and causes subsequent dysfunction in the cochlear ribbon synapses, which in turn leads to hearing changes and early stage presbycusis. Stria vascularis (SV) cells are vital for hearing function. However, it is unclear to what extent D-gal induces oxidative damage and apoptosis in the cochlear SV of mice. In addition, the source of the causative ROS in the cochlear SV has not been fully investigated. METHODS In this study, we investigated ROS generation in the cochlear SV of mice treated with D-gal. Hearing function was measured using the auditory brainstem response (ABR). Immunofluorescence was used to examine apoptosis and oxidative damage. Transmission electron microscopy was also used to investigate the mitochondrial ultrastructure. DNA fragmentation was determined using the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Mitochondrial membrane potential (MMP) and ATP were also measured. RESULTS We found that D-gal-treated mice exhibited a significant shift in the mean amplitude and latency of the ABR; a remarkable increase in the levels of NADPH oxidase (NOX-2), Uncoupling protein 2 (UCP2) and cleaved caspase-3 (c-Cas3) was observed, as well as an increase in the number of TUNEL-positive cells were observed in the SV of mice. Both the expression of the DNA oxidative damage biomarker 8-hydroxy-2-deoxyguanosine (8-OHdG) and a commonly occurring mitochondrial DNA deletion were markedly elevated in the SV of mice that had been treated with D-gal to induce aging. Conversely, the ATP level and MMP were significantly reduced in D-gal-induced aging mice. We also found alterations in the mitochondrial ultrastructure in the SV of aging mice, which include swollen and distorted mitochondrial shape, shortened and thickened microvilli, and the accumulation of lysosomes in the SV. CONCLUSION Our findings suggest that the impairment of cochlear SV during presbycusis may be caused by mitochondrial oxidative damage and subsequent apoptosis.
Collapse
Affiliation(s)
- Zhe Peng
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No.95, Yong'an Road, Xicheng District, Beijing, 100050, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China
| | - Chunli Zhao
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No.95, Yong'an Road, Xicheng District, Beijing, 100050, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China
| | - Zijing Yang
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No.95, Yong'an Road, Xicheng District, Beijing, 100050, China
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No.95, Yong'an Road, Xicheng District, Beijing, 100050, China.
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China.
| | - Zhengde Du
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, No.95, Yong'an Road, Xicheng District, Beijing, 100050, China.
- Clinical Center for Hearing Loss, Capital Medical University, Beijing, 100050, China.
| |
Collapse
|
5
|
Ding R, Pan Y, Chen K, Zou T, Zhang A, Guo D, Ji P, Fan C, Ye B, Xiang M. Spatio-temporal pattern of c-Jun N-terminal kinase isoforms in the cochleae of C57BL/6J mice with presbycusis. Hear Res 2023; 434:108784. [PMID: 37172415 DOI: 10.1016/j.heares.2023.108784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/16/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023]
Abstract
The c-Jun N-terminal kinase (JNK) pathway is a vital component of the mitogen-activated protein kinase cascade, which regulates cell death and survival. The present study aimed to explore the Spatio-temporal changes in all JNK isoforms in the cochleae of C57/BL6J mice with age-related hearing loss. Changes in the three isoforms of JNKs in the cochleae of an animal model with presbycusis and the senescent HEI-OC1 cell line were tested by immunohistochemistry staining and western blotting. Our results demonstrated that all three JNK isoforms are distributed in the cochleae, and the expression patterns of JNK1, JNK2, and JNK3 differed in hair cells, spiral ganglion neurons, and stria vascularis, with great significance in the cochleae of adult C57BL/6J mice. The levels of JNK1, JNK2, and JNK3 showed various spatio-temporal changes in the aging mice. In a senescent hair cell model, changes in JNK1, JNK2, and JNK3 expression levels were similar to those observed in the cochleae. Our study is the first to show that JNK3 is highly expressed in the hair cells of C57BL/6J mice and further increases in conjunction with age-related hearing loss, suggesting that it may play a more critical role than previously believed in hair cell loss and spiral ganglion degeneration.
Collapse
Affiliation(s)
- Rui Ding
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Pan
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kaili Chen
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Tianyuan Zou
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Andi Zhang
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Dongye Guo
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peilin Ji
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cui Fan
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Ye
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Mingliang Xiang
- Department of Otolaryngology & Head and Neck Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| |
Collapse
|
6
|
Urata S, Okabe S. Three-dimensional mouse cochlea imaging based on the modified Sca/eS using confocal microscopy. Anat Sci Int 2023:10.1007/s12565-023-00703-z. [PMID: 36773194 DOI: 10.1007/s12565-023-00703-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/13/2023] [Indexed: 02/12/2023]
Abstract
The three-dimensional stria vascularis (SV) and cochlear blood vessel structure is essential for inner ear function. Here, modified Sca/eS, a sorbitol-based optical-clearing method, was reported to visualize SV and vascular structure in the intact mouse cochlea. Cochlear macrophages as well as perivascular-resident macrophage-like melanocytes were detected as GFP-positive cells of the CX3CR1+/GFP mice. This study's method was effective in elucidating inner ear function under both physiological and pathological conditions.
Collapse
Affiliation(s)
- Shinji Urata
- Department of Otolaryngology, Graduate School of Medicine, University of Tokyo, Tokyo, 113-0033, Japan.
| | - Shigeo Okabe
- Department of Cellular Neurobiology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| |
Collapse
|
7
|
Alizadeh Y, Jalali MM, Sehati A. Association of different severity of diabetic retinopathy and hearing loss in type 2 diabetes mellitus. Am J Otolaryngol 2022; 43:103383. [PMID: 35124403 DOI: 10.1016/j.amjoto.2022.103383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/31/2021] [Accepted: 01/30/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE Microvascular involvement in patients with diabetes mellitus is one of the causes of retinopathy, nephropathy, and neuropathy. The same pathologic processes may occur in the inner ear structures. This case-control study aimed to evaluate the hearing thresholds in type 2 diabetic patients with different severity of diabetic retinopathy (DR) and to compare these findings with controls. MATERIALS AND METHODS We evaluated the hearing threshold in four groups of eligible subjects aged 20-70 years. These groups were controls, diabetic patients with no-DR, with mild-moderate non-proliferative DR (NPDR), and with severe NPDR/proliferative DR (PDR). Each group consisted of 105 subjects. Speech-frequency and high-frequency hearing levels (SFHL and HFHL, respectively) were measured and log-transformed. Analysis of covariance was used. The prevalence rate of moderate or more hearing loss in the groups was estimated. RESULTS In total, 194 men and 226 women participated. The ratio of means of SFHL and HFHL between PDR and controls was 0.18 and 0.20, respectively. Hearing loss was prevalent in severe NPDR/PDR (adjusted prevalence ratio 3.36 for SFHL and 1.51 for HFHL) compared to controls. Also, the prevalence of high-frequency hearing loss was more in mild-moderate NPDR (adjusted prevalence ratio 1.33). CONCLUSIONS The magnitude of the increase in hearing impairment prevalence between the severe NPDR/PDR patients and controls was about 24% for both SFHL and HFHL. We recommend hearing assessment in the screening of the DR patients.
Collapse
Affiliation(s)
- Yousef Alizadeh
- Department of Ophthalmology, Eye Research Center, Guilan University of Medical Sciences, Rasht, Iran
| | - Mir Mohammad Jalali
- Otorhinolaryngology Research Center, Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
| | - Asieh Sehati
- Otorhinolaryngology Research Center, Department of Otolaryngology and Head and Neck Surgery, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| |
Collapse
|
8
|
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] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [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
|
9
|
Abstract
Diabetes (type 2) and sensorineural hearing loss are common health problems manifested with ageing. While both type 1 and type 2 diabetes have been associated with hearing loss, a causal link has been difficult to establish. Individuals with diabetes have twice the incidence of hearing loss compared to those without diabetes and those with prediabetes have a 30% higher rate of hearing loss. Whether hearing loss is associated with diabetes independent of glycemic control remains to be determined. Hearing loss has its own set of risk factors and shares others with diabetes. This review will summarize the complex relationship between diabetes and sensorineural hearing loss.
Collapse
Affiliation(s)
- Dorit Samocha-Bonet
- Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia; St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, 2010, Australia.
| | - Buffy Wu
- Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia; School of Medical Sciences, UNSW Sydney, Kensington, NSW, 2052, Australia
| | - David K Ryugo
- Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia; School of Medical Sciences, UNSW Sydney, Kensington, NSW, 2052, Australia; Department of Otolaryngology Head and Neck and Skull Base Surgery, St. Vincent's Hospital, Darlinghurst, NSW, 2010, Australia
| |
Collapse
|
10
|
Gu J, Tong L, Lin X, Chen Y, Wu H, Wang X, Yu D. The disruption and hyperpermeability of blood-labyrinth barrier mediates cisplatin-induced ototoxicity. Toxicol Lett 2021; 354:56-64. [PMID: 34757176 DOI: 10.1016/j.toxlet.2021.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/21/2021] [Accepted: 10/27/2021] [Indexed: 12/20/2022]
Abstract
The ototoxic mechanisms of cisplatin on the organ of Corti and spiral ganglion neurons have been extensively studied, while few studies have been focused on the stria vascularis (SV). Herein, we verified the functional and morphological impairment in SV induced by a single injection of cisplatin (12 mg/kg, I.P.), represented by a reduction in Endocochlear Potentials (EP) and strial atrophy, and explored underlying mechanisms. Our results revealed increased extravasation of chromatic tracers (Evans blue dye and FITC-dextran) around microvessels after cisplatin exposure. The increased vascular permeability could be attributed to changes of pericytes (PCs) and perivascular-resident macrophage-like melanocytes (PVM/Ms) in number or morphology, as well as the enhanced level of HIF-1α and downstream VEGF. This capillary leakage led to a high accumulation of cisplatin in the perivascular space in SV, and disrupted the integrity of blood-labyrinth barrier (BLB). Also, tight junction (ZO-1) loosening and Na+, K+-ATPase damage was considered to be other critical contributors of BLB breakdown, which resulted in EP drop and consequent hearing loss. This study explored the role of stria vascularis in cisplatin-induced ototoxicity in terms of BLB hyperpermeability and pointed to a novel therapeutic target for the prevention of cisplatin-related hearing loss.
Collapse
|
11
|
Saume A, Thiry M, Defourny J. LDLR expression in the cochlea suggests a role in endolymph homeostasis and cochlear amplification. Hear Res 2021; 409:108311. [PMID: 34311268 DOI: 10.1016/j.heares.2021.108311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/22/2021] [Accepted: 07/08/2021] [Indexed: 11/23/2022]
Abstract
There is now growing evidence that hypercholesterolemia and high serum levels of low-density lipoproteins (LDL) predispose to sensorineural hearing loss. Circulating LDL-cholesterol is delivered to peripheral tissues via LDL receptor (LDLR) -mediated endocytosis. Recently, it has been shown that LDLR gene polymorphisms are associated with higher susceptibility to sudden deafness. These findings suggested that we should investigate the expression of LDLR from the postnatal maturation of the mouse cochlea until adulthood. In the cochlea of newborn mice, we observed that LDLR is mostly expressed in the lateral wall of the cochlea, especially in a band of cells directly facing the cochlear duct. Moreover, LDLR is expressed in the inner and outer hair cells, as well as in the adjacent greater epithelial ridge. In early postnatal stages, LDLR is expressed in the marginal cells of the immature stria vascularis, in the root cells of the spiral ligament, and in the adjacent outer sulcus cells. At the same time, LDLR begins to be expressed in the pillar cells of the immature organ of Corti. From the onset of hearing, LDLR is expressed in the marginal cells of the stria vascularis, in the outer sulcus cells, and in the capillaries of the adjacent spiral ligament. In the organ of Corti, LDLR is expressed in outer pillar cells and Deiters' cells, i.e. in the non-sensory supporting cells that directly surround the outer hair cells. These cells are believed to provide a mechanical coupling with the outer hair cells to modulate electromotility and cochlear amplification. In the stria vascularis of three-month-old mice, LDLR is further expressed in both marginal and intermediate cells. Overall, our results suggest that LDLR is mostly present in cochlear cells that are involved in endolymph homeostasis and cochlear amplification. Further functional studies will be needed to unravel how LDLR regulates extracellular and intracellular levels of cholesterol and lipoproteins in the cochlea, and how it could influence cochlear homeostasis.
Collapse
|
12
|
Stephenson R, Mangasarian A, Ishiyama G, Hosokawa K, Hosokawa S, Ishiyama A, Lopez IA. Immunohistochemical location of Na +, K +-ATPase α1 subunit in the human inner ear. Hear Res 2020; 400:108113. [PMID: 33221698 DOI: 10.1016/j.heares.2020.108113] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 10/20/2020] [Accepted: 11/09/2020] [Indexed: 01/12/2023]
Abstract
Na+, K+-ATPase (Na,K-ATPase) is an ubiquitous enzyme in the inner ear and a key factor in the maintenance of the osmotic gradient of the endolymph. This study uses Na,K-ATPase α1 subunit immunoreactivity (IR) to identify cellular structures in the normal and disease human cochlea. Formalin-fixed celloidin-embedded (FFCE) human temporal bone sections were immunoreacted with mouse monoclonal antibodies against Na,K-ATPase α1 subunit. Na,K-ATPase α1 IR was examined in the cochlea of 30 patients: four with normal hearing, 5 with Meniere's disease, and 21 with other inner ear diseases: 11 male, 19 female; ages 42 to 96 years-old (yo), average age of 77 yo. Na,K-ATPase α1 IR area was quantified using the ImageJ software program. Na,K-ATPase α1 IR was located in the stria vascularis, and in type I, II and IV fibrocytes of the spiral ligament in the cochlea from patients with normal hearing. Na,K-ATPase α1 IR was seen in Deiters's cells and inner phalangeal cells of the organ of Corti. Na,K-ATPase α1 IR was present in satellite cells that surround the neurons of the spiral ganglia. In the inner ear of pathological specimens, Na,K-ATPase IR area was decreased (compared to the normal) in the stria vascularis, supporting cells in the organ of Corti and satellite cells of the spiral ganglia. These results show that Na,K-ATPase α1 IR is a good marker to identify cellular structures of the human inner ear and may be used to study cellular changes in the cochlea associated with aging and disease. The ubiquitous localization of Na,K-ATPase α1 in the human cochlea is consistent with the Na,K-ATPase role in ionic homeostasis and osmolarity, similar to that seen in animal models.
Collapse
Affiliation(s)
- Ryan Stephenson
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA
| | - Astkhik Mangasarian
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA
| | - Gail Ishiyama
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA
| | - Kumiko Hosokawa
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA; Department of Otorhinolaryngology/ Head & Neck Surgery, c Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Seiji Hosokawa
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA; Department of Otorhinolaryngology/ Head & Neck Surgery, c Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Akira Ishiyama
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA
| | - Ivan A Lopez
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, USA.
| |
Collapse
|
13
|
Zhang L, Wu X, Lin X. Gene therapy for genetic mutations affecting non-sensory cells in the cochlea. Hear Res 2020; 394:107858. [PMID: 31791650 DOI: 10.1016/j.heares.2019.107858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/13/2019] [Accepted: 11/22/2019] [Indexed: 01/15/2023]
Abstract
Congenital hearing loss (HL) affects about 1 in every 500 infants. Among those affected more than half are caused by genetic mutations. According to the cellular sites affected by mutations in the cochlea, deafness genes could be classified into three major groups: those affecting the function of hair cells and synapses, cochlear supporting cells, and cells in the stria vascularis (SV) as well as in the lateral wall. The second and third groups account for more than half of all sensorineural hearing loss (SNHL) cases caused by genetic mutations. Current major treatment options for SNHL patients are hearing aids and cochlear implants (CIs). Hearing aids can only help patients with moderate to severe HL. Resolution of CIs is still improving and these devices are quite expensive especially when lifetime rehabilitation and maintenance costs are included. Tremendous efforts have been made to find novel treatments that are expected to restore hearing with higher-resolution and more natural quality, and to have a significantly lower cost over the lifetime of uses. Gene therapy studies have made impressive progresses in preclinical trials. This review focuses on deafness genes that affect supporting cells and cells in the SV of the cochlea. We will discuss recent progresses and remaining challenges for gene therapies targeting mutations in deafness genes belonging to this category.
Collapse
Affiliation(s)
- Li Zhang
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China; Department of Otolaryngology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322-3030, USA
| | - Xuewen Wu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital of Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, China; Department of Otolaryngology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322-3030, USA
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322-3030, USA.
| |
Collapse
|
14
|
Sai N, Zhang T, Wu J, Han WJ. [Noise-induced blood-labyrinth-barrier trauma of guinea pig and the protective effect of matrix metalloproteinase inhibitors]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2020; 55:363-370. [PMID: 32306634 DOI: 10.3760/cma.j.cn115330-20190424-00303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: The research is to study the expression and distribution of matrix metalloproteinase (MMPs)-2 and -9 in the guinea pig cochlea after noise exposure, and to explore the role of MMPs in the blood-labyrinth-barrier (BLB). In addition, the role of MMPs inhibitor doxycycline in noise-induced BLB trauma was studied as well, which provides the basis for further studies and prophylaxis of noise-induced hearing loss. Methods: A total of 45 healthy adult guinea pigs were randomly divided into the control group (15 received intraperitoneal injection of 0.9% saline for 4 consecutive days), the noise-exposure group (15 exposed by 120 dB SPL white noise for 4 h per day for continuous 2 d, intraperitoneal injection of normal saline for 4 consecutive days) and the noise-exposure + doxycycline group (15 exposed by 120 dB SPL white noise exposure for 4 h per day for 2 consecutive days, and intraperitoneal injection of doxycycline 50 mg/kg/d for 4 consecutive days), respectively. Immunofluorescence staining, western blot, and real-time quantitative PCR were used to analyze the distribution and differential expression of MMP-2 and -9 in the stria vascularis of guinea pigs in comparison with the normal control group, noise only group, and noise & doxycycline treatment group. Immunofluorescence staining was used to observe the changes in tight junction (TJ) protein ZO-1 in stria vascularis in three groups and to investigate the effect of acoustic injury on TJs. And ABR tests were utilized to detect the hearing function of guinea pigs in the three groups. Intravenous Evans blue was administrated intravenously as an indicator of vascular leakage among three groups to study the changes in BLB permeability in context of acoustic injury. SPSS 22.0 was used for statistical analysis. Results: There was no significant difference in hearing function between the noise-exposure group and the noise & doxycycline group two hours after noise exposure. After seven, 14 and 28 days noise exposure, the hearing recovery of the noise & doxycycline treatment group was significantly greater than that of the noise-exposure group (P<0.05) . Immunofluorescence staining showed that there was only a small amount of MMP-2 and -9 in the stria vascular in the normal control group, and ZO-1 showed dense linear expression. While, in the noise-explore group, MMP-2 and -9 in the stria vascular was significantly elevated (P<0.05), and the configuration of ZO-1 became loose and discontinuous. However, the MMP-2 and -9 in the noise & doxycycline treatment group were not significantly different from the normal control group (P>0.05), which were significantly less than that in the noise-exposure group, and just a little break of ZO-1 was observed, however, the overall structure remained dense. The leakage of Evans blue from stria vascular capillary in the noise-exposure group was significantly increased, and the difference between the other two groups did not show any statistical significance (P>0.05). Conclusions: The damage of tight junction structure induced by MMP-2 and -9 may play an important role in BLB destruction. In addition, doxycycline can inhibit MMPs secretion, thereby, to some extent, protecting the integrity of BLB from acoustic injury, and contributing to the long-term hearing recovery.
Collapse
Affiliation(s)
- N Sai
- College of Otorhinolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, National Clinical Research Center for Otorhinolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing 100853, China
| | - T Zhang
- College of Otorhinolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, National Clinical Research Center for Otorhinolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing 100853, China
| | - J Wu
- College of Otorhinolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, National Clinical Research Center for Otorhinolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing 100853, China; the Former Department of the Political Work Department of the Military Commission, Beijing 100120, China
| | - W J Han
- College of Otorhinolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, National Clinical Research Center for Otorhinolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing 100853, China
| |
Collapse
|
15
|
Tian C, Johnson KR. TBX1 is required for normal stria vascularis and semicircular canal development. Dev Biol 2019; 457:91-103. [PMID: 31550482 DOI: 10.1016/j.ydbio.2019.09.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/12/2019] [Accepted: 09/20/2019] [Indexed: 12/15/2022]
Abstract
Little is known about the role of TBX1 in post-otocyst stages of inner ear development. Here, we report on mice with a missense mutation of Tbx1 that are viable with fully developed but abnormally formed inner ears. Mutant mice are deaf due to an undeveloped stria vascularis and show vestibular dysfunction associated with abnormal semicircular canal formation. We show that TBX1 is expressed in endolymph-producing strial marginal cells and vestibular dark cells of the inner ear and is an upstream regulator of Esrrb, which previously was shown to control the developmental fate of these cells. We also show that TBX1 is expressed in sensory cells of the crista ampullaris, which may relate to the semicircular canal abnormalities observed in mutant mice. Inner ears of mutant embryos have a non-resorbed fusion plate in the posterior semicircular canal and a single ampulla connecting anterior and lateral canals. We hypothesize that the TBX1 missense mutation prevents binding with specific co-regulatory proteins. These findings reveal previously unknown functions of TBX1 during later stages of inner ear development.
Collapse
Affiliation(s)
- Cong Tian
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA
| | | |
Collapse
|
16
|
Abstract
The Dach1 gene is expressed in the inner ear of normal mouse embryos in the area that differentiates into the cochlear stria vascularis (SV). We hypothesised that Dach1 downregulation in the inner ear would lead to SV dysplasia. However, because Dach1 knockout is embryonic lethal in mice, the role of Dach1 in the inner ear is unclear. Here, we established inner ear-specific Dach1-knockdown mice and showed that Dach1 downregulation resulted in hearing loss, reduced endocochlear potential and secondary outer hair cell loss. There were no abnormalities in marginal cells and basal cells in the SV or spiral ligament in inner ear-specific Dach1-knockdown mature mice. However, intermediate cell dysplasia and thinning of the SV were observed. Moreover, dynamic changes in the expression of key genes related to the epithelial-mesenchymal transition were observed in the lateral wall of the cochlear epithelium, which differentiated into the SV in inner ear-specific Dach1-knockdown mice at embryonic stages. In summary, suppression of Dach1 expression in the inner ear caused the epithelial-mesenchymal transition in the lateral wall of cochlear epithelium, resulting in loss of intermediate cells in the SV and SV dysplasia. This article has an associated First Person interview with the first author of the paper. Summary: Inner ear-specific downregulation of Dach1 reveals that the epithelial–mesenchymal transition is crucial for the generation of the stria vascularis.
Collapse
Affiliation(s)
- Toru Miwa
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan .,Otolaryngology-Head and Neck Surgery, JCHO Kumamoto General Hospital, Kumamoto 8668660, Japan
| | - Ryosei Minoda
- Otolaryngology-Head and Neck Surgery, JCHO Kumamoto General Hospital, Kumamoto 8668660, Japan
| | - Yoshihide Ishikawa
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Tomohito Kajii
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Yorihisa Orita
- Department of Otolaryngology and Head and Neck Surgery, Graduate of School of Medicine, Kumamoto University, Kumamoto 8608556, Japan
| | - Takahiro Ohyama
- USC-Tina and Rick Caruso Department of Otolaryngology-Head & Neck Surgery, Zilkha Neurogenetic Institute, USC Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| |
Collapse
|
17
|
Liu T, Li G, Noble KV, Li Y, Barth JL, Schulte BA, Lang H. Age-dependent alterations of Kir4.1 expression in neural crest-derived cells of the mouse and human cochlea. Neurobiol Aging 2019; 80:210-222. [PMID: 31220650 PMCID: PMC6679794 DOI: 10.1016/j.neurobiolaging.2019.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 04/02/2019] [Accepted: 04/11/2019] [Indexed: 11/18/2022]
Abstract
Age-related hearing loss (or presbyacusis) is a progressive pathophysiological process. This study addressed the hypothesis that degeneration/dysfunction of multiple nonsensory cell types contributes to presbyacusis by evaluating tissues obtained from young and aged CBA/CaJ mouse ears and human temporal bones. Ultrastructural examination and transcriptomic analysis of mouse cochleas revealed age-dependent pathophysiological alterations in 3 types of neural crest-derived cells, namely intermediate cells in the stria vascularis, outer sulcus cells in the cochlear lateral wall, and satellite cells in the spiral ganglion. A significant decline in immunoreactivity for Kir4.1, an inwardly rectifying potassium channel, was seen in strial intermediate cells and outer sulcus cells in the ears of older mice. Age-dependent alterations in Kir4.1 immunostaining also were observed in satellite cells ensheathing spiral ganglion neurons. Expression alterations of Kir4.1 were observed in these same cell populations in the aged human cochlea. These results suggest that degeneration/dysfunction of neural crest-derived cells maybe an important contributing factor to both metabolic and neural forms of presbyacusis.
Collapse
Affiliation(s)
- Ting Liu
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Gang Li
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology, Tinnitus and Hyperacusis Center, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Kenyaria V Noble
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Yongxi Li
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Jeremy L Barth
- Department of Regenerative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Bradley A Schulte
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, USA.
| |
Collapse
|
18
|
Wang X, Zhang J, Li G, Sai N, Han J, Hou Z, Kachelmeier A, Shi X. Vascular regeneration in adult mouse cochlea stimulated by VEGF-A 165 and driven by NG2-derived cells ex vivo. Hear Res 2019; 377:179-188. [PMID: 30954884 DOI: 10.1016/j.heares.2019.03.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/21/2019] [Accepted: 03/13/2019] [Indexed: 12/20/2022]
Abstract
Can damaged or degenerated vessels be regenerated in the ear? The question is clinically important, as disruption of cochlear blood flow is seen in a wide variety of hearing disorders, including in loud sound-induced hearing loss (endothelial injury), ageing-related hearing loss (lost vascular density), and genetic hearing loss (e.g., Norrie disease: strial avascularization). Progression in cochlear blood flow (CBF) pathology can parallel progression in hair cell and hearing loss. However, neither new vessel growth in the ear, nor the role of angiogenesis in hearing, have been investigated. In this study, we used an established ex vivo tissue explant model in conjunction with a matrigel matrix model to demonstrate for the first time that new vessels can be generated by activating a vascular endothelial growth factor (VEGF-A) signal. Most intriguingly, we found that the pattern of the newly formed vessels resembles the natural 'mesh pattern' of in situ strial vessels, with both lumen and expression of tight junctions. Sphigosine-1-phosphate (S1P) in synergy with VEGF-A control new vessel size and growth. Using transgenic neural/glial antigen 2 (NG2) fluorescent reporter mice, we have furthermore discovered that the progenitors of "de novo" strial vessels are NG2-derived cells. Taken together, our data demonstrates that damaged strial microvessels can be regenerated by reprogramming NG2-derived angiogenic cells. Restoration of the functional vasculature may be critical for recovery of vascular dysfunction related hearing loss.
Collapse
Affiliation(s)
- Xiaohan Wang
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA; Boston Children's Hospital, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Jinhui Zhang
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Guangshuai Li
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Na Sai
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Jiang Han
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Zhiqiang Hou
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Allan Kachelmeier
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Xiaorui Shi
- Oregon Hearing Research Center, Department of Otolaryngology / Head & Neck Surgery, Oregon Health & Science University, Portland, OR, 97239, USA.
| |
Collapse
|
19
|
Heeringa AN, Köppl C. The aging cochlea: Towards unraveling the functional contributions of strial dysfunction and synaptopathy. Hear Res 2019; 376:111-124. [PMID: 30862414 DOI: 10.1016/j.heares.2019.02.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 02/01/2019] [Accepted: 02/26/2019] [Indexed: 10/27/2022]
Abstract
Strial dysfunction is commonly observed as a key consequence of aging in the cochlea. A large body of animal research, especially in the quiet-aged Mongolian gerbil, shows specific histopathological changes in the cochlear stria vascularis and the putatively corresponding effects on endocochlear potential and auditory nerve responses. However, recent work suggests that synaptopathy, or the loss of inner hair cell-auditory nerve fiber synapses, also presents as a consequence of aging. It is now believed that the loss of synapses is the earliest age-related degenerative event. The present review aims to integrate classic and novel research on age-related pathologies of the inner ear. First, we summarize current knowledge on age-related strial dysfunction and synaptopathy. We describe how these cochlear pathologies fit into the categories for presbyacusis, as first defined by Schuknecht in the '70s. Further, we discuss how strial dysfunction and synaptopathy affect sound coding by the auditory nerve and how they can be experimentally induced to study their specific contributions to age-related hearing deficits. As such, we aim to give an overview of the current literature on age-related cochlear pathologies and hope to inspire further research on the role of cochlear aging in age-related hearing deficits.
Collapse
Affiliation(s)
- Amarins N Heeringa
- Cluster of Excellence 'Hearing4all' and Research Centre Neurosensory Science, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany
| | - Christine Köppl
- Cluster of Excellence 'Hearing4all' and Research Centre Neurosensory Science, Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky University Oldenburg, 26129, Oldenburg, Germany.
| |
Collapse
|
20
|
Hori T, Sugahara K, Tsuda J, Hirose Y, Hashimoto M, Takemoto Y, Tarumoto S, Yamashita H. Oral administration of an herbal medicine to prevent progressive hearing loss in a mouse model of diabetes. Auris Nasus Larynx 2019; 46:703-708. [PMID: 30799140 DOI: 10.1016/j.anl.2019.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/10/2019] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Tsumura Suzuki Obese Diabetes (TSOD) mice exhibit early age-associated hearing loss. Histopathological analysis of these mice shows narrowing of capillaries in the stria vascularis and chronic reduction of blood flow in the cochlea. In this study, we investigated the effect of oral administration of a herbal medicine or calorie restriction on hearing in TSOD mice. METHODS TSOD mice were divided into 4 groups: CR (calorie restriction), BF and DS (treated with the herbal medicines, Bofutsushosan and Daisaikoto, respectively), and the control group. Body weight, blood glucose levels, and auditory brainstem responses (ABRs) were measured. The cochleae were excised and evaluated histopathologically. RESULTS Blood glucose levels were suppressed in the CR, BF, and DS groups. In addition, the elevation of ABR thresholds was inhibited in the CR, BF, and DS groups. Cochlear blood vessels remained wide in the three treatment groups compared with the control group. These results suggested that the administration of these herbal medicines improved glucose tolerance and yielded results similar to those on calorie restriction. CONCLUSION Oral administration of 2 herbal medicines can prevent hearing function disorder in a model mouse of diabetes. The results may clarify the possibility of clinical application.
Collapse
Affiliation(s)
- Takeshi Hori
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Kazuma Sugahara
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Junko Tsuda
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Yoshinobu Hirose
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Makoto Hashimoto
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Yousuke Takemoto
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Shunsuke Tarumoto
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan
| | - Hiroshi Yamashita
- Department of Otolaryngology, Yamaguchi University Graduate School of Medicine, Ube, Japan.
| |
Collapse
|
21
|
Kakigi A, Okada T, Takeda T, Uehara N, Nibu KI. Endocytosis of CF in marginal cells of stria vascularis regulated by ROCK and MLCK signaling cascade, but not G-proteins. Auris Nasus Larynx 2019; 46:790-796. [PMID: 30739815 DOI: 10.1016/j.anl.2019.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/14/2019] [Accepted: 01/17/2019] [Indexed: 01/24/2023]
Abstract
Objective The endocytosis of cationized feritin (CF) via a clathrin-mediated pathway is regulated by a signaling network. Marginal cells showed the active endocytosis of CF via a clathrin-mediated pathway. The internalization of receptors through this clathrin-mediated pathway is an important regulatory event in signal transduction. Numerous kinases are involved in endocytosis, and each endocytic route is subjected to high-order regulation by cellular signaling mechanisms. In this study, we investigated whether ROCK and MLCK signaling cascades and G-proteins regulate the endocytosis of CF in marginal cells of the stria vascularis. Methods CF was infused into the cochlear duct with pertussis toxin (PTX),Clostridium botulinum C3 toxin (BTX), guanosine(g-thio)-triphosphate (GTP-γS), ML-7, Y-27632. Endocytic activity was measured at 30 min after the start of infusion under an electron microscope. Results In marginal cells, CF was internalized via a clathrin-mediated pathway that depends on F-actin and microtubules (MT). Its processes were controlled by myosin light chain kinase (MLCK) and Rho-associated kinase (ROCK), but not affected by G-protein-coupled receptor (GPCR) or the RhoA signaling cascade. Conclusion Our previous study showed that the main endocytotic pathway of microperoxidase (MPO) did not depend on the Rho/ROCK molecular switch or actin/myosin motor system, but was mainly regulated by the RhoA signaling cascade. The present study results indicate that these signaling cascades regulating CF internalization completely differ from the cascades for MPO internalization.
Collapse
Affiliation(s)
- Akinobu Kakigi
- Department of Otolaryngology-Head & Neck Surgery, Kobe University, Graduate School of Medicine, Hyogo, Japan.
| | - Teruhiko Okada
- Department of Anatomy, Kochi Medical School, Nankoku, Kochi, Japan
| | - Taizo Takeda
- Department of Otolaryngology, Kochi Medical School, Nankoku, Kochi, Japan
| | - Natsumi Uehara
- Department of Otolaryngology-Head & Neck Surgery, Kobe University, Graduate School of Medicine, Hyogo, Japan
| | - Ken-Ichi Nibu
- Department of Otolaryngology-Head & Neck Surgery, Kobe University, Graduate School of Medicine, Hyogo, Japan
| |
Collapse
|
22
|
Ritter KE, Martin DM. Neural crest contributions to the ear: Implications for congenital hearing disorders. Hear Res 2018; 376:22-32. [PMID: 30455064 DOI: 10.1016/j.heares.2018.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/30/2018] [Accepted: 11/12/2018] [Indexed: 12/16/2022]
Abstract
Congenital hearing disorders affect millions of children worldwide and can significantly impact acquisition of speech and language. Efforts to identify the developmental genetic etiologies of conductive and sensorineural hearing losses have revealed critical roles for cranial neural crest cells (NCCs) in ear development. Cranial NCCs contribute to all portions of the ear, and defects in neural crest development can lead to neurocristopathies associated with profound hearing loss. The molecular mechanisms governing the development of neural crest derivatives within the ear are partially understood, but many questions remain. In this review, we describe recent advancements in determining neural crest contributions to the ear, how they inform our understanding of neurocristopathies, and highlight new avenues for further research using bioinformatic approaches.
Collapse
Affiliation(s)
- K Elaine Ritter
- Department of Pediatrics, The University of Michigan Medical School, Ann Arbor, MI, USA
| | - Donna M Martin
- Department of Pediatrics, The University of Michigan Medical School, Ann Arbor, MI, USA; Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA.
| |
Collapse
|
23
|
Ding B, Walton JP, Zhu X, Frisina RD. Age-related changes in Na, K-ATPase expression, subunit isoform selection and assembly in the stria vascularis lateral wall of mouse cochlea. Hear Res 2018; 367:59-73. [PMID: 30029086 DOI: 10.1016/j.heares.2018.07.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/02/2018] [Accepted: 07/06/2018] [Indexed: 11/26/2022]
Abstract
Due to the critical role of cochlear ion channels for hearing, the focus of the present study was to examine age-related changes of Na, K-ATPase (NKA) subunits in the lateral wall of mouse cochlea. We combined qRT-PCR, western blot and immunocytochemistry methodologies in order to determine gene and protein expression levels in the lateral wall of young and aged CBA/CaJ mice. Of the seven NKA subunits, only the mRNA expressions of α1, β1 and β2 subunit isoforms were detected in the lateral wall of CBA/CaJ mice. Aging was accompanied by dys-regulation of gene and protein expression of all three subunits detected. Hematoxylin and eosin (H&E) staining revealed atrophy of the cochlear stria vascularis (SV). The SV atrophy rate (20%) was much less than the ∼80% decline in expression of all three NKA isoforms, indicating lateral wall atrophy and NKA dys-regulation are independent factors and that there is a combination of changes involving the morphology of SV and NKA expression in the aging cochlea which may concomitantly affect cochlear function. Immunoprecipitation assays showed that the α1-β1 heterodimer is the selective preferential heterodimer over the α1-β2 heterodimer in cochlea lateral wall. Interestingly, in vitro pathway experiments utilizing cultured mouse cochlear marginal cells from the SV (SV-K1 cells) indicated that decreased mRNA and protein expressions of α1, β1 and β2 subunit isoforms are not associated with reduction of NKA activity following in vitro application of ouabain, but ouabain did disrupt the α1-β1 heterodimer interaction. Lastly, the association between the α1 and β1 subunit isoforms was present in the cochlear lateral wall of young adult mice, but this interaction could not be detected in old mice. Taken together, these data suggest that in the young adult mouse there is a specific, functional selection and assembly of NKA subunit isoforms in the SV lateral wall, which is disrupted and dys-regulated with age. Interventions for this age-linked ion channel disruption may have the potential to help diagnose, prevent, or treat age-related hearing loss.
Collapse
Affiliation(s)
- Bo Ding
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - Joseph P Walton
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA.
| | - Xiaoxia Zhu
- Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| | - Robert D Frisina
- Dept. Communication Sciences & Disorders, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Chemical & Biomedical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA; Dept. Medical Engineering, Global Center for Hearing & Speech Research, University of South Florida, Tampa, FL, USA
| |
Collapse
|
24
|
Chen W, Hao QQ, Ren LL, Ren W, Lin HS, Guo WW, Yang SM. Cochlear morphology in the developing inner ear of the porcine model of spontaneous deafness. BMC Neurosci 2018; 19:28. [PMID: 29716524 PMCID: PMC5930852 DOI: 10.1186/s12868-018-0426-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/18/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Auditory function and cochlear morphology have previously been described in a porcine model with spontaneous WS2-like phenotype. In the present study, cochlear histopathology was further investigated in the inner ear of the developing spontaneous deafness pig. RESULTS We found that the stria vascularis transformed into a complex tri-laminar tissue at embryonic 85 days (E85) in normal pigs, but not in the MITF-/- pigs. As the neural crest (NC) of cochlea was derived by melanocytes. MITF mutation caused failure of development of melanocytes which caused a subsequent collapse of cochlear duct and deficits of the epithelium after E100. Furthermore, the spiral ganglion neurons of cochlea in the MITF-/- pigs began to degenerate at postnatal 30 days (P30). Thus, our histopathological results indicated that the malformation of the stria vascularis was a primary defect in MITF-/- induced WT pigs which was resulted from the loss of NC-derived melanocytes. Subsequently, the cochleae underwent secondary degeneration of the vestibular organs. As the degeneration of spiral ganglion neurons happened after P30, it suggests that WS patients should be considered as candidates for cochlear implant. CONCLUSIONS Our porcine model of MITF-M mutation may provide a crucial animal model for cochlear implant, cell therapy in patients with congenital hereditary hearing loss.
Collapse
Affiliation(s)
- Wei Chen
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China
| | - Qing-Qing Hao
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China
| | - Li-Li Ren
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China
| | - Wei Ren
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China
| | - Hui-Sang Lin
- Department of Biotechnology, Dalian Medical University, Dalian, 116044, Liaoning, China
| | - Wei-Wei Guo
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China.
| | - Shi-Ming Yang
- Department of Otolaryngology, Head & Neck Surgery, Institute of Otolaryngology, Chinese PLA General Hospital, Beijing Key Laboratory of Hearing Impairment Prevention and Treatment, Key Laboratory of Hearing Impairment Science, Chinese PLA Medical School,Ministry of Education, Beijng, China.
| |
Collapse
|
25
|
Ohlemiller KK, Kaur T, Warchol ME, Withnell RH. The endocochlear potential as an indicator of reticular lamina integrity after noise exposure in mice. Hear Res 2018; 361:138-151. [PMID: 29426600 DOI: 10.1016/j.heares.2018.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/23/2018] [Accepted: 01/30/2018] [Indexed: 12/19/2022]
Abstract
The endocochlear potential (EP) provides part of the electrochemical drive for sound-driven currents through cochlear hair cells. Intense noise exposure (110 dB SPL, 2 h) differentially affects the EP in three inbred mouse strains (C57BL/6 [B6], CBA/J [CBA], BALB/cJ [BALB]) (Ohlemiller and Gagnon, 2007, Hearing Research 224:34-50; Ohlemiller et al., 2011, JARO 12:45-58). At least for mice older than 3 mos, B6 mice are unaffected, CBA mice show temporary EP reduction, and BALB mice may show temporary or permanent EP reduction. EP reduction was well correlated with histological metrics for injury to stria vascularis and spiral ligament, and little evidence was found for holes or tears in the reticular lamina that might 'short out' the EP. Thus we suggested that the genes and processes that underlie the strain EP differences primarily impact cochlear lateral wall, not the organ of Corti. Our previous work did not test the range of noise exposure conditions over which strain differences apply. It therefore remained possible that the relation between exposure severity and acute EP reduction simply has a higher exposure threshold in B6 mice compared to CBA and BALB. We also did not test for age dependence. It is well established that young adult animals are especially vulnerable to noise-induced permanent threshold shifts (NIPTS). It is unknown, however, whether heightened vulnerability of the lateral wall contributes to this condition. The present study extends our previous work to multiple noise exposure levels and durations, and explicitly compares young adult (6-7 wks) and older mice (>4 mos). We find that the exposure level-versus-acute EP relation is dramatically strain-dependent, such that B6 mice widely diverge from both CBA and BALB. For all three strains, however, acute EP reduction is greater in young mice. Above 110 dB SPL, all mice exhibited rapid and severe EP reduction that is likely related to tearing of the reticular lamina. By contrast, EP-versus-noise duration examined at 104 dB suggested that different processes contribute to EP reduction in young and older mice. The average EP falls to a constant level after ∼7.5 min in older mice, but progressively decreases with further exposure in young mice. Confocal microscopy of organ of Corti surface preparations stained for phalloidin and zonula occludens-1 (ZO-1) indicated this corresponds to rapid loss of outer hair cells (OHCs) and formation of both holes and tears in the reticular lamina of young mice. In addition, when animals exposed at 119 dB were allowed to recover for 1 mo, only young B6 mice showed collapse of the EP to ≤5 mV. Confocal analysis suggested novel persistent loss of tight junctions in the lateral organ of Corti. This may allow paracellular leakage that permanently reduces the EP. From our other findings, we propose that noise-related lateral wall pathology in young CBA and BALB mice promotes hair cell loss and opening of the reticular lamina. The heightened vulnerability of young adult animals to noise exposure may in part reflect special sensitivity of the organ of Corti to acute lateral wall dysfunction at younger ages. This feature appears genetically modifiable.
Collapse
MESH Headings
- Age Factors
- Animals
- Auditory Threshold
- Computer Simulation
- Disease Models, Animal
- Evoked Potentials, Auditory
- Hair Cells, Auditory/metabolism
- Hair Cells, Auditory/pathology
- Hearing Loss, Noise-Induced/metabolism
- Hearing Loss, Noise-Induced/pathology
- Hearing Loss, Noise-Induced/physiopathology
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Models, Biological
- Noise
- Species Specificity
- Spiral Lamina/metabolism
- Spiral Lamina/pathology
- Spiral Lamina/physiopathology
- Tight Junctions/metabolism
- Tight Junctions/pathology
- Time Factors
- Zonula Occludens-1 Protein/metabolism
Collapse
Affiliation(s)
- Kevin K Ohlemiller
- Washington University School of Medicine, Department of Otolaryngology, Central Institute for the Deaf at Washington University School of Medicine, Fay and Carl Simons Center for Hearing and Deafness, Saint Louis MO, USA.
| | - Tejbeer Kaur
- Washington University School of Medicine, Department of Otolaryngology, Central Institute for the Deaf at Washington University School of Medicine, Fay and Carl Simons Center for Hearing and Deafness, Saint Louis MO, USA
| | - Mark E Warchol
- Washington University School of Medicine, Department of Otolaryngology, Central Institute for the Deaf at Washington University School of Medicine, Fay and Carl Simons Center for Hearing and Deafness, Saint Louis MO, USA
| | - Robert H Withnell
- Department of Speech and Hearing Sciences, Indiana University, Bloomington IN, USA
| |
Collapse
|
26
|
Monsanto RDC, Schachern P, Paparella MM, Cureoglu S, Penido NDO. Progression of changes in the sensorial elements of the cochlear and peripheral vestibular systems: The otitis media continuum. Hear Res 2017; 351:2-10. [PMID: 28578877 DOI: 10.1016/j.heares.2017.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/10/2017] [Accepted: 05/03/2017] [Indexed: 12/16/2022]
Abstract
Our study aimed to evaluate pathologic changes in the cochlear (inner and outer hair cells and stria vascularis) and vestibular (vestibular hair cells, dark, and transitional cells) sensorial elements in temporal bones from donors who had otitis media. We studied 40 temporal bones from such donors, which were categorized in serous otitis media (SOM), serous-purulent otitis media (SPOM), mucoid/mucoid-purulent otitis media (MOM/MPOM), and chronic otitis media (COM); control group comprised 10 nondiseased temporal bones. We found significant loss of inner and outer cochlear hair cells in the basal turn of the SPOM, MOM/MPOM and COM groups; significant loss of vestibular hair cells was observed in the MOM/MPOM and COM groups. All otitis media groups had smaller mean area of the stria vascularis in the basal turn of the cochlea when compared to controls. In conclusion, our study demonstrated more severe pathologic changes in the later stages of the continuum of otitis media (MOM/MPOM and COM). Those changes seem to progress from the basal turn of the cochlea (stria vascularis, then inner and outer hair cells) to the middle turn of the cochlea and to the saccule and utricle in the MOM/MPOM and COM stages.
Collapse
Affiliation(s)
- Rafael da Costa Monsanto
- Department of Otolaryngology, University of Minnesota, 2001 6th St. SE, Lions Research Building, Room 210, Otopathology Laboratory, Minneapolis, MN 55455, USA; Department of Otorhinolaryngology Head and Neck Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina, Rua dos Otonis, 700 - Piso Superior - Vila Clementino, São Paulo, SP 04025 002, Brazil
| | - Patricia Schachern
- Department of Otolaryngology, University of Minnesota, 2001 6th St. SE, Lions Research Building, Room 210, Otopathology Laboratory, Minneapolis, MN 55455, USA
| | - Michael M Paparella
- Department of Otolaryngology, University of Minnesota, 2001 6th St. SE, Lions Research Building, Room 210, Otopathology Laboratory, Minneapolis, MN 55455, USA
| | - Sebahattin Cureoglu
- Department of Otolaryngology, University of Minnesota, 2001 6th St. SE, Lions Research Building, Room 210, Otopathology Laboratory, Minneapolis, MN 55455, USA.
| | - Norma de Oliveira Penido
- Department of Otorhinolaryngology Head and Neck Surgery, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina, Rua dos Otonis, 700 - Piso Superior - Vila Clementino, São Paulo, SP 04025 002, Brazil
| |
Collapse
|
27
|
Ding D, Liu H, Qi W, Jiang H, Li Y, Wu X, Sun H, Gross K, Salvi R. Ototoxic effects and mechanisms of loop diuretics. J Otol 2016; 11:145-56. [PMID: 29937824 DOI: 10.1016/j.joto.2016.10.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 12/22/2022] Open
Abstract
Over the past two decades considerable progress has been made in understanding the ototoxic effects and mechanisms underlying loop diuretics. As typical representative of loop diuretics ethacrynic acid or furosemide only induces temporary hearing loss, but rarely permanent deafness unless applied in severe acute or chronic renal failure or with other ototoxic drugs. Loop diuretic induce unique pathological changes in the cochlea such as formation of edematous spaces in the epithelium of the stria vascularis, which leads to rapid decrease of the endolymphatic potential and eventual loss of the cochlear microphonic potential, summating potential, and compound action potential. Loop diuretics interfere with strial adenylate cyclase and Na+/K+-ATPase and inhibit the Na-K-2Cl cotransporter in the stria vascularis, however recent reports indicate that one of the earliest effects in vivo is to abolish blood flow in the vessels supplying the lateral wall. Since ethacrynic acid does not damage the stria vascularis in vitro, the changes in Na+/K+-ATPase and Na-K-2Cl seen in vivo may be secondary effects results from strial ischemia and anoxia. Recent observations showing that renin is present in pericytes surrounding stria arterioles suggest that diuretics may induce local vasoconstriction by renin secretion and angiotensin formation. The tight junctions in the blood-cochlea barrier prevent toxic molecules and pathogens from entering cochlea, but when diuretics induce a transient ischemia, the barrier is temporarily disrupted allowing the entry of toxic chemicals or pathogens.
Collapse
|
28
|
Meehan DT, Delimont D, Dufek B, Zallocchi M, Phillips G, Gratton MA, Cosgrove D. Endothelin-1 mediated induction of extracellular matrix genes in strial marginal cells underlies strial pathology in Alport mice. Hear Res 2016; 341:100-108. [PMID: 27553900 DOI: 10.1016/j.heares.2016.08.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/21/2016] [Accepted: 08/15/2016] [Indexed: 12/20/2022]
Abstract
Alport syndrome, a type IV collagen disorder, manifests as glomerular disease associated with hearing loss with thickening of the glomerular and strial capillary basement membranes (SCBMs). We have identified a role for endothelin-1 (ET-1) activation of endothelin A receptors (ETARs) in glomerular pathogenesis. Here we explore whether ET-1 plays a role in strial pathology. Wild type (WT) and Alport mice were treated with the ETAR antagonist, sitaxentan. The stria vascularis was analyzed for SCBM thickness and for extracellular matrix (ECM) proteins. Additional WT and Alport mice were exposed to noise or hypoxia and the stria analyzed for hypoxia-related and ECM genes. A strial marginal cell line cultured under hypoxic conditions, or stimulated with ET-1 was analyzed for expression of hypoxia-related and ECM transcripts. Noise exposure resulted in significantly elevated ABR thresholds in Alport mice relative to wild type littermates. Alport stria showed elevated expression of collagen α1(IV), laminin α2, and laminin α5 proteins relative to WT. SCBM thickening and elevated ECM protein expression was ameliorated by ETAR blockade. Stria from normoxic Alport mice and hypoxic WT mice showed upregulation of hypoxia-related, ECM, and ET-1 transcripts. Both ET-1 stimulation and hypoxia up-regulated ECM transcripts in cultured marginal cells. We conclude that ET-1 mediated activation of ETARs on strial marginal cells results in elevated expression of ECM genes and thickening of the SCBMs in Alport mice. SCBM thickening results in hypoxic stress further elevating ECM and ET-1 gene expression, exacerbating strial pathology.
Collapse
Affiliation(s)
| | | | - Brianna Dufek
- Boys Town National Research Hospital, Omaha, NE, USA
| | | | | | | | - Dominic Cosgrove
- Boys Town National Research Hospital, Omaha, NE, USA; University of Nebraska Medical Center, Omaha, NE, USA.
| |
Collapse
|
29
|
Miyazaki H, Wangemann P, Marcus DC. The gastric H,K-ATPase in stria vascularis contributes to pH regulation of cochlear endolymph but not to K secretion. BMC Physiol 2016; 17:1. [PMID: 27515813 PMCID: PMC4982335 DOI: 10.1186/s12899-016-0024-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/29/2016] [Indexed: 01/22/2023]
Abstract
BACKGROUND Disturbance of acid-base balance in the inner ear is known to be associated with hearing loss in a number of conditions including genetic mutations and pharmacologic interventions. Several previous physiologic and immunohistochemical observations lead to proposals of the involvement of acid-base transporters in stria vascularis. RESULTS We directly measured acid flux in vitro from the apical side of isolated stria vascularis from adult C57Bl/6 mice with a novel constant-perfusion pH-selective self-referencing probe. Acid efflux that depended on metabolism and ion transport was observed from the apical side of stria vascularis. The acid flux was decreased to about 40 % of control by removal of the metabolic substrate (glucose-free) and by inhibition of the sodium pump (ouabain). The flux was also decreased a) by inhibition of Na,H-exchangers by amiloride, dimethylamiloride (DMA), S3226 and Hoe694, b) by inhibition of Na,2Cl,K-cotransporter (NKCC1) by bumetanide, and c) by the likely inhibition of HCO3/anion exchange by DIDS. By contrast, the acid flux was increased by inhibition of gastric H,K-ATPase (SCH28080) but was not affected by an inhibitor of vH-ATPase (bafilomycin). K flux from stria vascularis was reduced less than 5 % by SCH28080. CONCLUSIONS These observations suggest that stria vascularis may be an important site of control of cochlear acid-base balance and demonstrate a functional role of several acid-base transporters in stria vascularis, including basolateral H,K-ATPase and apical Na,H-exchange. Previous suggestions that H secretion is mediated by an apical vH-ATPase and that basolateral H,K-ATPase contributes importantly to K secretion in stria vascularis are not supported. These results advance our understanding of inner ear acid-base balance and provide a stronger basis to interpret the etiology of genetic and pharmacologic cochlear dysfunctions that are influenced by endolymphatic pH.
Collapse
Affiliation(s)
- Hiromitsu Miyazaki
- Department of Anatomy & Physiology, Cellular Biophysics Laboratory, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802 USA
- Deparment of Anatomy & Physiology, Cell Physiology Laboratory, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802 USA
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, 980-8574 Japan
| | - Philine Wangemann
- Deparment of Anatomy & Physiology, Cell Physiology Laboratory, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802 USA
| | - Daniel C. Marcus
- Department of Anatomy & Physiology, Cellular Biophysics Laboratory, Kansas State University, 228 Coles Hall, Manhattan, KS 66506-5802 USA
| |
Collapse
|
30
|
Abstract
INTRODUCTION As otology enters the field of gene therapy and human studies commence, the question arises whether audiograms - the current gold standard for the evaluation of hearing function - can consistently predict cellular damage within the human inner ear and thus should be used to define inclusion criteria for trials. Current assumptions rely on the analysis of small groups of human temporal bones post mortem or from psychophysical identification of cochlear "dead regions" in vivo, but a comprehensive study assessing the correlation between audiometric thresholds and cellular damage within the cochlea is lacking. METHODS A total of 131 human temporal bones from 85 adult individuals (ages 19-92 years, median 69 years) with sensorineural hearing loss due to various etiologies were analyzed. Cytocochleograms - which quantify loss of hair cells, neurons, and strial atrophy along the length of the cochlea - were compared with subjects' latest available audiometric tests prior to death (time range 5 h-22 years, median 24 months). The Greenwood function and the equivalent rectangular bandwidth were used to infer, from cytocochleograms, cochlear locations corresponding to frequencies tested in clinical audiograms. Correlation between audiometric thresholds at clinically tested frequencies and cell type-specific damage in those frequency regions was examined by calculating Spearman's correlation coefficients. RESULTS Similar audiometric profiles reflected widely different cellular damage in the cochlea. In our diverse group of patients, audiometric thresholds tended to be more influenced by hair cell loss than by neuronal loss or strial atrophy. Spearman's correlation coefficient across frequencies was at most 0.7 and often below 0.5, with 1.0 indicating perfect correlation. CONCLUSIONS Audiometric thresholds do not predict specific cellular damage in the human inner ear. Our study highlights the need for better non- or minimally-invasive tools, such as cochlear endoscopy, to establish cellular-level diagnosis and thereby guide therapy and monitor response to treatment.
Collapse
Affiliation(s)
- Lukas D Landegger
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02141, United States; Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, United States; Department of Otolaryngology, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
| | - Demetri Psaltis
- Optics Laboratory, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), BM 4102 (Bâtiment BM), Station 17, 1015 Lausanne, Switzerland.
| | - Konstantina M Stankovic
- Eaton Peabody Laboratories, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02141, United States; Department of Otolaryngology, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, United States; Harvard Program in Speech and Hearing Bioscience and Technology, 260 Longwood Avenue, Boston, MA 02115, United States.
| |
Collapse
|
31
|
Teissier N, Bernard S, Quesnel S, Van Den Abbeele T. Audiovestibular consequences of congenital cytomegalovirus infection. Eur Ann Otorhinolaryngol Head Neck Dis 2016; 133:413-8. [PMID: 27067701 DOI: 10.1016/j.anorl.2016.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Congenital cytomegalovirus (CMV) infection is the second most frequent cause of mental retardation and sensorineural hearing loss, after genetic factors. Recently, pediatric forensic and fetopathological studies have led to progress in understanding the pathophysiological mechanisms underlying the various neurosensory sequelae. Thanks to the identification of certain prognostic factors of hearing loss, therapeutic protocols based on antiviral molecules are now proposed for target populations. This treatment has shown efficacy in limiting hearing threshold deterioration and even, in some cases, seems to provide partial recovery of hearing in symptomatic congenitally infected CMV neonates. However, optimal treatment duration and administration modalities are not clearly defined. This article reviews recent data concerning audiovestibular sequelae and their management in children congenitally infected by CMV.
Collapse
|
32
|
Reiss LAJ, Stark G, Nguyen-Huynh AT, Spear KA, Zhang H, Tanaka C, Li H. Morphological correlates of hearing loss after cochlear implantation and electro-acoustic stimulation in a hearing-impaired Guinea pig model. Hear Res 2015; 327:163-74. [PMID: 26087114 DOI: 10.1016/j.heares.2015.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/30/2015] [Accepted: 06/03/2015] [Indexed: 01/25/2023]
Abstract
Hybrid or electro-acoustic stimulation (EAS) cochlear implants (CIs) are designed to provide high-frequency electric hearing together with residual low-frequency acoustic hearing. However, 30-50% of EAS CI recipients lose residual hearing after implantation. The objective of this study was to determine the mechanisms of EAS-induced hearing loss in an animal model with high-frequency hearing loss. Guinea pigs were exposed to 24 h of noise (12-24 kHz at 116 dB) to induce a high-frequency hearing loss. After recovery, two groups of animals were implanted (n = 6 per group), with one group receiving chronic acoustic and electric stimulation for 10 weeks, and the other group receiving no stimulation during this time frame. A third group (n = 6) was not implanted, but received chronic acoustic stimulation. Auditory brainstem responses were recorded biweekly to monitor changes in hearing. The organ of Corti was immunolabeled with phalloidin, anti-CtBP2, and anti-GluR2 to quantify hair cells, ribbons and post-synaptic receptors. The lateral wall was immunolabeled with phalloidin and lectin to quantify stria vascularis capillary diameters. Bimodal or trimodal diameter distributions were observed; the number and location of peaks were objectively determined using the Aikake Information Criterion and Expectation Maximization algorithm. Noise exposure led to immediate hearing loss at 16-32 kHz for all groups. Cochlear implantation led to additional hearing loss at 4-8 kHz; this hearing loss was negatively and positively correlated with minimum and maximum peaks of the bimodal or trimodal distributions of stria vascularis capillary diameters, respectively. After chronic stimulation, no significant group changes in thresholds were seen; however, elevated thresholds at 1 kHz in implanted, stimulated animals were significantly correlated with decreased presynaptic ribbon and postsynaptic receptor counts. Inner and outer hair cell counts did not differ between groups and were not correlated with threshold shifts at any frequency. As in the previous study in a normal-hearing model, stria vascularis capillary changes were associated with immediate hearing loss after implantation, while little to no hair cell loss was observed even in cochlear regions with threshold shifts as large as 40-50 dB. These findings again support a role of lateral wall blood flow changes, rather than hair cell loss, in hearing loss after surgical trauma, and implicate the endocochlear potential as a factor in implantation-induced hearing loss. Further, the analysis of the hair cell ribbons and post-synaptic receptors suggest that delayed hearing loss may be linked to synapse or peripheral nerve loss due to stimulation excitotoxicity or inflammation. Further research is needed to separate these potential mechanisms of delayed hearing loss.
Collapse
Affiliation(s)
- Lina A J Reiss
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
| | - Gemaine Stark
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Anh T Nguyen-Huynh
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kayce A Spear
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Hongzheng Zhang
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Department of Otolaryngology Head & Neck Surgery, Zhujiang Hospital of Southern Medical University, Guangzhou 510280, China
| | - Chiemi Tanaka
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA; Department of Communication Sciences and Disorders, John A. Burns School of Medicine, University of Hawai'i at Mānoa, 677 Ala Moana Blvd, Honolulu, HI 96816, USA
| | - Hongzhe Li
- Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| |
Collapse
|
33
|
Suzuki M, Sakamoto T, Kashio A, Yamasoba T. Age-related morphological changes in the basement membrane in the stria vascularis of C57BL/6 mice. Eur Arch Otorhinolaryngol 2015; 273:57-62. [PMID: 25555607 DOI: 10.1007/s00405-014-3478-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 12/25/2014] [Indexed: 10/24/2022]
Abstract
Basement membrane anionic sites (BMAS) are involved in the selective transport of electrically charged macromolecules in cochlear capillaries. Using cationic polyethyleneimine (PEI), we examined age-related changes in BMAS in the cochleae of C57BL/6 mice. The mice were grouped according to age as follows: 3 days, 4 weeks, 8 weeks, 6 months, and 12 months. In the right bony labyrinths, widths of the stria vascularis were measured in paraffin-embedded sections using light microscopy. The left bony labyrinths were immersed in a 0.5 % cationic PEI solution and embedded in epoxy resin. Ultrathin sections of the left cochlea were examined using transmission electron microscopy. A significant difference in stria vascularis width was observed between the 4-week-old and 12-month-old mice. The PEI distribution in the capillary and epithelial basement membranes (BMs) of the cochlea was observed. In all animals, PEI particles were evenly distributed in the capillary BM of the spiral ligament and in the subepithelial BM of Reissner's membrane. In the stria vascularis, PEI particles were evenly distributed in the capillary BM in 3-day-old mice. In 4- and 8-week-old mice, PEI particle sizes were markedly lower than those observed in 3-day-old mice. In 6- and 12-month-old mice, PEI particles were hardly detected in the strial capillary BM. In the strial capillary BM in these mice, the laminae rarae externa and interna disappeared, but the lamina densa became larger. We speculated that age-related changes of strial capillary BMAS may affect electrically charged macromolecule transport systems in the stria vascularis of C57BL/6 mice.
Collapse
Affiliation(s)
- Mitsuya Suzuki
- Department of Otolaryngology, Toho University Sakura Medical Center, 564-1 Shimo-shizu, Sakura City, Chiba, 285-0841, Japan.
| | - Takashi Sakamoto
- Department of Otolaryngology, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | - Akinori Kashio
- Department of Otolaryngology, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| | - Tatsuya Yamasoba
- Department of Otolaryngology, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan
| |
Collapse
|
34
|
Ito T, Li X, Kurima K, Choi BY, Wangemann P, Griffith AJ. Slc26a4-insufficiency causes fluctuating hearing loss and stria vascularis dysfunction. Neurobiol Dis 2014; 66:53-65. [PMID: 24561068 DOI: 10.1016/j.nbd.2014.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 02/03/2014] [Accepted: 02/10/2014] [Indexed: 12/13/2022] Open
Abstract
SLC26A4 mutations can cause a distinctive hearing loss phenotype with sudden drops and fluctuation in patients. Existing Slc26a4 mutant mouse lines have a profound loss of hearing and vestibular function, with severe inner ear malformations that do not model this human phenotype. In this study, we generated Slc26a4-insufficient mice by manipulation of doxycycline administration to a transgenic mouse line in which all Slc26a4 expression was under the control of doxycycline. Doxycycline was administered from conception to embryonic day 17.5, and then it was discontinued. Auditory brainstem response thresholds showed significant fluctuation of hearing loss from 1 through 3months of age. The endocochlear potential, which is required for inner ear sensory cell function, correlated with auditory brainstem response thresholds. We observed degeneration of stria vascularis intermediate cells, the cells that generate the endocochlear potential, but no other abnormalities within the cochlea. We conclude that fluctuations of hearing result from fluctuations of the endocochlear potential and stria vascularis dysfunction in Slc26a4-insufficient mouse ears. This model can now be used to test potential interventions to reduce or prevent sudden hearing loss or fluctuation in human patients. Our strategy to generate a hypomorphic mouse model utilizing the tet-on system will be applicable to other diseases in which a hypomorphic allele is needed to model the human phenotype.
Collapse
|
35
|
Yang H, Xiong H, Huang Q, Pang J, Zheng X, Chen L, Yu R, Zheng Y. Compromised potassium recycling in the cochlea contributes to conservation of endocochlear potential in a mouse model of age-related hearing loss. Neurosci Lett 2013; 555:97-101. [PMID: 24055606 DOI: 10.1016/j.neulet.2013.09.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 05/10/2013] [Accepted: 09/10/2013] [Indexed: 12/13/2022]
Abstract
The C57BL/6 strain is considered an excellent model to study age-related hearing loss (AHL). Aging C57BL/6 mice are characterized by profound hearing loss but conservation of the endocochlear potential (EP). Here we show 12-month-old C57BL/6 mice display a notable hearing loss at 4, 8, 16 and 32kHz while the EP is maintained at normal level. Morphological examination shows significant outer hair cells loss in the cochlear basal turn and atrophy of the stria vascularis (SV). Fluorescence immunohistochemical studies reveal that potassium channel KCNJ10 and KCNQ1 expression dramatically decreased in the SV. Concomitant with this, mRNA levels of KCNJ10 and KCNQ1 are also reduced. In addition, three other potassium transporters, including α1-Na,K-ATPase, α2-Na,K-ATPase and NKCC1, reduce their expression at mRNA levels as well. These observations suggest that conservation of the EP in aging C57BL/6 mice is attributable to the SV generating a new balance for potassium influx and efflux at a relatively lower level.
Collapse
Affiliation(s)
- Haidi Yang
- Department of Otolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, China; Institute of Hearing and Speech-Language Science, Sun Yat-sen University, China
| | | | | | | | | | | | | | | |
Collapse
|