1
|
Bovee S, Klump GM, Köppl C, Pyott SJ. The Stria Vascularis: Renewed Attention on a Key Player in Age-Related Hearing Loss. Int J Mol Sci 2024; 25:5391. [PMID: 38791427 PMCID: PMC11121695 DOI: 10.3390/ijms25105391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related hearing loss (HL), or presbycusis, is a complex and heterogeneous condition, affecting a significant portion of older adults and involving various interacting mechanisms. Metabolic presbycusis, a type of age-related HL, is characterized by the dysfunction of the stria vascularis, which is crucial for maintaining the endocochlear potential necessary for hearing. Although attention on metabolic presbycusis has waned in recent years, research continues to identify strial pathology as a key factor in age-related HL. This narrative review integrates past and recent research, bridging findings from animal models and human studies, to examine the contributions of the stria vascularis to age-related HL. It provides a brief overview of the structure and function of the stria vascularis and then examines mechanisms contributing to age-related strial dysfunction, including altered ion transport, changes in pigmentation, inflammatory responses, and vascular atrophy. Importantly, this review outlines the contribution of metabolic mechanisms to age-related HL, highlighting areas for future research. It emphasizes the complex interdependence of metabolic and sensorineural mechanisms in the pathology of age-related HL and highlights the importance of animal models in understanding the underlying mechanisms. The comprehensive and mechanistic investigation of all factors contributing to age-related HL, including cochlear metabolic dysfunction, remains crucial to identifying the underlying mechanisms and developing personalized, protective, and restorative treatments.
Collapse
Affiliation(s)
- Sonny Bovee
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
| | - Georg M. Klump
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
- Cluster of Excellence “Hearing4all”, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Centre Neurosensory Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Christine Köppl
- Department of Neuroscience, School of Medicine and Health Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany; (S.B.); (G.M.K.); (C.K.)
- Cluster of Excellence “Hearing4all”, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
- Research Centre Neurosensory Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Sonja J. Pyott
- Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
- The Research School of Behavioural and Cognitive Neurosciences, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
| |
Collapse
|
2
|
Thulasiram MR, Yamamoto R, Olszewski RT, Gu S, Morell RJ, Hoa M, Dabdoub A. Molecular differences between neonatal and adult stria vascularis from organotypic explants and transcriptomics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.24.590986. [PMID: 38712156 PMCID: PMC11071502 DOI: 10.1101/2024.04.24.590986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Summary The stria vascularis (SV), part of the blood-labyrinth barrier, is an essential component of the inner ear that regulates the ionic environment required for hearing. SV degeneration disrupts cochlear homeostasis, leading to irreversible hearing loss, yet a comprehensive understanding of the SV, and consequently therapeutic availability for SV degeneration, is lacking. We developed a whole-tissue explant model from neonatal and adult mice to create a robust platform for SV research. We validated our model by demonstrating that the proliferative behaviour of the SV in vitro mimics SV in vivo, providing a representative model and advancing high-throughput SV research. We also provided evidence for pharmacological intervention in our system by investigating the role of Wnt/β-catenin signaling in SV proliferation. Finally, we performed single-cell RNA sequencing from in vivo neonatal and adult mouse SV and revealed key genes and pathways that may play a role in SV proliferation and maintenance. Together, our results contribute new insights into investigating biological solutions for SV-associated hearing loss. Significance Hearing loss impairs our ability to communicate with people and interact with our environment. This can lead to social isolation, depression, cognitive deficits, and dementia. Inner ear degeneration is a primary cause of hearing loss, and our study provides an in depth look at one of the major sites of inner ear degeneration: the stria vascularis. The stria vascularis and associated blood-labyrinth barrier maintain the functional integrity of the auditory system, yet it is relatively understudied. By developing a new in vitro model for the young and adult stria vascularis and using single cell RNA sequencing, our study provides a novel approach to studying this tissue, contributing new insights and widespread implications for auditory neuroscience and regenerative medicine. Highlights - We established an organotypic explant system of the neonatal and adult stria vascularis with an intact blood-labyrinth barrier. - Proliferation of the stria vascularis decreases with age in vitro , modelling its proliferative behaviour in vivo . - Pharmacological studies using our in vitro SV model open possibilities for testing injury paradigms and therapeutic interventions. - Inhibition of Wnt signalling decreases proliferation in neonatal stria vascularis.- We identified key genes and transcription factors unique to developing and mature SV cell types using single cell RNA sequencing.
Collapse
|
3
|
Qin T, So KKH, Hui CC, Sham MH. Ptch1 is essential for cochlear marginal cell differentiation and stria vascularis formation. Cell Rep 2024; 43:114083. [PMID: 38602877 DOI: 10.1016/j.celrep.2024.114083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 02/27/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024] Open
Abstract
A common cause of deafness in humans is dysregulation of the endocochlear potential generated by the stria vascularis (SV). Thus, proper formation of the SV is critical for hearing. Using single-cell transcriptomics and a series of Shh signaling mutants, we discovered that the Shh receptor Patched1 (Ptch1) is essential for marginal cell (MC) differentiation and SV formation. Single-cell RNA sequencing analyses revealed that the cochlear roof epithelium is already specified into discrete domains with distinctive gene expression profiles at embryonic day 14, with Gsc as a marker gene of the MC lineage. Ptch1 deficiency leads to defective specification of MC precursors along the cochlear basal-apical regions. We demonstrated that elevated Gli2 levels impede MC differentiation through sustaining Otx2 expression and maintaining the progenitor state of MC precursors. Our results uncover an early specification of cochlear non-sensory epithelial cells and establish a crucial role of the Ptch1-Gli2 axis in regulating the development of SV.
Collapse
Affiliation(s)
- Tianli Qin
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China; School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China
| | - Karl Kam Hei So
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China
| | - Chi-Chung Hui
- Program in Developmental & Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Mai Har Sham
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China.
| |
Collapse
|
4
|
Beaulac HJ, Munnamalai V. Localization of cadherins in the postnatal cochlear epithelium and their relation to space formation. Dev Dyn 2024. [PMID: 38264972 DOI: 10.1002/dvdy.692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/25/2024] Open
Abstract
The sensory epithelium of the cochlea, the organ of Corti, has complex cytoarchitecture consisting of mechanosensory hair cells intercalated by epithelial support cells. The support cells provide important trophic and structural support to the hair cells. Thus, the support cells must be stiff yet compliant enough to withstand and modulate vibrations to the hair cells. Once the sensory cells are properly patterned, the support cells undergo significant remodeling from a simple epithelium into a structurally rigid epithelium with fluid-filled spaces in the murine cochlea. Cell adhesion molecules such as cadherins are necessary for sorting and connecting cells in an intact epithelium. To create the fluid-filled spaces, cell adhesion properties of adjoining cell membranes between cells must change to allow the formation of spaces within an epithelium. However, the dynamic localization of cadherins has not been properly analyzed as these spaces are formed. There are three cadherins that are reported to be expressed during the first postnatal week of development when the tunnel of Corti forms in the cochlea. In this study, we characterize the dynamic localization of cadherins that are associated with cytoskeletal remodeling at the contacting membranes of the inner and outer pillar cells flanking the tunnel of Corti.
Collapse
|
5
|
Beaulac HJ, Munnamalai V. Localization of Cadherins in the postnatal cochlear epithelium and their relation to space formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.30.560287. [PMID: 37808730 PMCID: PMC10557783 DOI: 10.1101/2023.09.30.560287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The sensory epithelium of the cochlea, the organ of Corti, has complex cytoarchitecture consisting of mechanosensory hair cells intercalated by epithelial support cells. The support cells provide important trophic and structural support to the hair cells. Thus, the support cells must be stiff yet compliant enough to withstand and modulate vibrations to the hair cells. Once the sensory cells are properly patterned, the support cells undergo significant remodeling from a simple epithelium into a structurally rigid epithelium with fluid-filled spaces in the murine cochlea. Cell adhesion molecules such as cadherins are necessary for sorting and connecting cells in an intact epithelium. To create the fluid-filled spaces, cell adhesion properties of adjoining cell membranes between cells must change to allow the formation of spaces within an epithelium. However, the dynamic localization of cadherins has not been properly analyzed as these spaces are formed. There are three cadherins that are reported to be expressed during the first postnatal week of development when the tunnel of Corti forms in the cochlea. In this study, we characterize the dynamic localization of cadherins that are associated with cytoskeletal remodeling at the contacting membranes of the inner and outer pillar cells flanking the tunnel of Corti. Key findings F-actin remodeling occurs between E18.5 to P7 in the cochlear sensory epithelium.Transient changes of F-actin cytoskeleton drives epithelial morphogenesis.Fluid-filled spaces in epithelium is driven by changes in cell adhesion.
Collapse
|
6
|
Rose KP, Manilla G, Milon B, Zalzman O, Song Y, Coate TM, Hertzano R. Spatially distinct otic mesenchyme cells show molecular and functional heterogeneity patterns before hearing onset. iScience 2023; 26:107769. [PMID: 37720106 PMCID: PMC10502415 DOI: 10.1016/j.isci.2023.107769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/29/2023] [Accepted: 08/25/2023] [Indexed: 09/19/2023] Open
Abstract
The cochlea consists of diverse cellular populations working in harmony to convert mechanical stimuli into electrical signals for the perception of sound. Otic mesenchyme cells (OMCs), often considered a homogeneous cell type, are essential for normal cochlear development and hearing. Despite being the most numerous cell type in the developing cochlea, OMCs are poorly understood. OMCs are known to differentiate into spatially and functionally distinct cell types, including fibrocytes of the lateral wall and spiral limbus, modiolar osteoblasts, and specialized tympanic border cells of the basilar membrane. Here, we show that OMCs are transcriptionally and functionally heterogeneous and can be divided into four distinct populations that spatially correspond to OMC-derived cochlear structures. We also show that this heterogeneity and complexity of OMCs commences during early phases of cochlear development. Finally, we describe the cell-cell communication network of the developing cochlea, inferring a major role for OMC in outgoing signaling.
Collapse
Affiliation(s)
- Kevin P. Rose
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gabriella Manilla
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Beatrice Milon
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ori Zalzman
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Thomas M. Coate
- Department of Biology, Georgetown University, Washington, DC 20007, USA
| | - Ronna Hertzano
- Neurotology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Otorhinolaryngology Head and Neck Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| |
Collapse
|
7
|
Forrester-Gauntlett B, Peters L, Oback B. Grainyhead-like 2 is required for morphological integrity of mouse embryonic stem cells and orderly formation of inner ear-like organoids. Front Cell Dev Biol 2023; 11:1112069. [PMID: 37745294 PMCID: PMC10513505 DOI: 10.3389/fcell.2023.1112069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Mutations in the transcription factor gene grainyhead-like 2 (GRHL2) are associated with progressive non-syndromic sensorineural deafness autosomal dominant type 28 (DFNA28) in humans. Since complete loss of Grhl2 is lethal in mouse embryos, we studied its role during inner ear pathology and hearing loss in vitro. To this end, we generated different homozygous deletions to knockout Grhl2 in mouse embryonic stem cells (Grhl2-KO ESCs), including some mimicking naturally occurring truncations in the dimerisation domain related to human DFNA28. Under naïve culture conditions, Grhl2-KO cells in suspension were more heterogenous in size and larger than wild-type controls. Adherent Grhl2-KO cells were also larger, with a less uniform shape, flattened, less circular morphology, forming loose monolayer colonies with poorly defined edges. These changes correlated with lower expression of epithelial cadherin Cdh1 but no changes in tight junction markers (Ocln, Tjp2) or other Grhl isoforms (Grhl1, Grhl3). Clonogenicity from single cells, proliferation rates of cell populations and proliferation markers were reduced in Grhl2-KO ESCs. We next induced stepwise directed differentiation of Grhl2-KO ESCs along an otic pathway, giving rise to three-dimensional inner ear-like organoids (IELOs). Quantitative morphometry revealed that Grhl2-KO cells initially formed larger IELOs with a less compacted structure, more eccentric shape and increased surface area. These morphological changes persisted for up to one week. They were partially rescued by forced cell aggregation and fully restored by stably overexpressing exogenous Grhl2 in Grhl2-KO ESCs, indicating that Grhl2 alters cell-cell interactions. On day 8, aggregates were transferred into minimal maturation medium to allow self-guided organogenesis for another two weeks. During this period, Grhl2-KO cells and wild-type controls developed similarly, expressing neural, neuronal and sensory hair cell markers, while maintaining their initial differences in size and shape. In summary, Grhl2 is required for morphological maintenance of ESCs and orderly formation of IELOs, consistent with an essential role in organising epithelial integrity during inner ear development. Our findings validate quantitative morphometry as a useful, non-invasive screening method for molecular phenotyping of candidate mutations during organoid development.
Collapse
Affiliation(s)
- Blaise Forrester-Gauntlett
- Animal Biotech, AgResearch, Hamilton, New Zealand
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Linda Peters
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Björn Oback
- Animal Biotech, AgResearch, Hamilton, New Zealand
- School of Science, University of Waikato, Hamilton, New Zealand
- School of Medical Sciences, University of Auckland, Auckland, New Zealand
| |
Collapse
|
8
|
Deuper L, Meuser M, Thiesler H, Jany UWH, Rudat C, Hildebrandt H, Trowe MO, Kispert A. Mesenchymal FGFR1 and FGFR2 control patterning of the ureteric mesenchyme by balancing SHH and BMP4 signaling. Development 2022; 149:276592. [DOI: 10.1242/dev.200767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 08/19/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The coordinated development of the mesenchymal and epithelial progenitors of the murine ureter depends on a complex interplay of diverse signaling activities. We have recently shown that epithelial FGFR2 signaling regulates stratification and differentiation of the epithelial compartment by enhancing epithelial Shh expression, and mesenchymal SHH and BMP4 activity. Here, we show that FGFR1 and FGFR2 expression in the mesenchymal primordium impinges on the SHH/BMP4 signaling axis to regulate mesenchymal patterning and differentiation. Mouse embryos with conditional loss of Fgfr1 and Fgfr2 in the ureteric mesenchyme exhibited reduced mesenchymal proliferation and prematurely activated lamina propria formation at the expense of the smooth muscle cell program. They also manifested hydroureter at birth. Molecular profiling detected increased SHH, WNT and retinoic acid signaling, whereas BMP4 signaling in the mesenchyme was reduced. Pharmacological activation of SHH signaling in combination with inhibition of BMP4 signaling recapitulated the cellular changes in explant cultures of wild-type ureters. Additional experiments suggest that mesenchymal FGFR1 and FGFR2 act as a sink for FGF ligands to dampen activation of Shh and BMP receptor gene expression by epithelial FGFR2 signaling.
Collapse
Affiliation(s)
- Lena Deuper
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| | - Max Meuser
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| | - Hauke Thiesler
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover 2 , 30625 Hannover , Germany
| | - Ulrich W. H. Jany
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| | - Carsten Rudat
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| | - Herbert Hildebrandt
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover 2 , 30625 Hannover , Germany
| | - Mark-Oliver Trowe
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| | - Andreas Kispert
- Institute of Molecular Biology, Medizinische Hochschule Hannover 1 , 30625 Hannover , Germany
| |
Collapse
|
9
|
Renauld JM, Khan V, Basch ML. Intermediate Cells of Dual Embryonic Origin Follow a Basal to Apical Gradient of Ingression Into the Lateral Wall of the Cochlea. Front Cell Dev Biol 2022; 10:867153. [PMID: 35372344 PMCID: PMC8964366 DOI: 10.3389/fcell.2022.867153] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 01/20/2023] Open
Abstract
Intermediate cells of the stria vascularis are neural crest derived melanocytes. They are essential for the establishment of the endocochlear potential in the inner ear, which allows mechanosensory hair cells to transduce sound into nerve impulses. Despite their importance for normal hearing, how these cells develop and migrate to their position in the lateral wall of the cochlea has not been studied. We find that as early as E10.5 some Schwann cell precursors in the VIIIth ganglion begin to express melanocyte specific markers while neural crest derived melanoblasts migrate into the otic vesicle. Intermediate cells of both melanoblast and Schwann cell precursor origin ingress into the lateral wall of the cochlea starting at around E15.5 following a basal to apical gradient during embryonic development, and continue to proliferate postnatally.
Collapse
Affiliation(s)
- Justine M Renauld
- Department of Otolaryngology, Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Vibhuti Khan
- Department of Otolaryngology, Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Martín L Basch
- Department of Otolaryngology, Head and Neck Surgery, Case Western Reserve University School of Medicine, Cleveland, OH, United States.,Department of Genetics and Genome Sciences, Case Western Reserve School of Medicine, Cleveland, OH, United States.,Department of Biology, Case Western Reserve University, Cleveland, OH, United States.,Department of Otolaryngology, Head and Neck Surgery, University Hospitals, Cleveland, OH, United States
| |
Collapse
|
10
|
Meuser M, Deuper L, Rudat C, Aydoğdu N, Thiesler H, Zarnovican P, Hildebrandt H, Trowe MO, Kispert A. FGFR2 signaling enhances the SHH-BMP4 signaling axis in early ureter development. Development 2022; 149:273983. [DOI: 10.1242/dev.200021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 12/09/2021] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The patterned array of basal, intermediate and superficial cells in the urothelium of the mature ureter arises from uncommitted epithelial progenitors of the distal ureteric bud. Urothelial development requires signaling input from surrounding mesenchymal cells, which, in turn, depend on cues from the epithelial primordium to form a layered fibro-muscular wall. Here, we have identified FGFR2 as a crucial component in this reciprocal signaling crosstalk in the murine ureter. Loss of Fgfr2 in the ureteric epithelium led to reduced proliferation, stratification, intermediate and basal cell differentiation in this tissue, and affected cell survival and smooth muscle cell differentiation in the surrounding mesenchyme. Loss of Fgfr2 impacted negatively on epithelial expression of Shh and its mesenchymal effector gene Bmp4. Activation of SHH or BMP4 signaling largely rescued the cellular defects of mutant ureters in explant cultures. Conversely, inhibition of SHH or BMP signaling in wild-type ureters recapitulated the mutant phenotype in a dose-dependent manner. Our study suggests that FGF signals from the mesenchyme enhance, via epithelial FGFR2, the SHH-BMP4 signaling axis to drive urothelial and mesenchymal development in the early ureter.
Collapse
Affiliation(s)
- Max Meuser
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Lena Deuper
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Carsten Rudat
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Nurullah Aydoğdu
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Hauke Thiesler
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Patricia Zarnovican
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Herbert Hildebrandt
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Andreas Kispert
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| |
Collapse
|
11
|
Billings SE, Myers NM, Quiruz L, Cheng AG. Opposing effects of Wnt/β-catenin signaling on epithelial and mesenchymal cell fate in the developing cochlea. Development 2021; 148:268974. [PMID: 34061174 PMCID: PMC8217710 DOI: 10.1242/dev.199091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 05/05/2021] [Indexed: 12/12/2022]
Abstract
During embryonic development, the otic epithelium and surrounding periotic mesenchymal cells originate from distinct lineages and coordinate to form the mammalian cochlea. Epithelial sensory precursors within the cochlear duct first undergo terminal mitosis before differentiating into sensory and non-sensory cells. In parallel, periotic mesenchymal cells differentiate to shape the lateral wall, modiolus and pericochlear spaces. Previously, Wnt activation was shown to promote proliferation and differentiation of both otic epithelial and mesenchymal cells. Here, we fate-mapped Wnt-responsive epithelial and mesenchymal cells in mice and found that Wnt activation resulted in opposing cell fates. In the post-mitotic cochlear epithelium, Wnt activation via β-catenin stabilization induced clusters of proliferative cells that dedifferentiated and lost epithelial characteristics. In contrast, Wnt-activated periotic mesenchyme formed ectopic pericochlear spaces and cell clusters showing a loss of mesenchymal and gain of epithelial features. Finally, clonal analyses via multi-colored fate-mapping showed that Wnt-activated epithelial cells proliferated and formed clonal colonies, whereas Wnt-activated mesenchymal cells assembled as aggregates of mitotically quiescent cells. Together, we show that Wnt activation drives transition between epithelial and mesenchymal states in a cell type-dependent manner. Summary: The developing cochlea comprises spatially and lineally distinct populations of epithelial and mesenchymal cells. This study shows the opposing effects of aberrant Wnt/β-catenin signaling on cell fates of cochlear epithelial and mesenchymal cells.
Collapse
Affiliation(s)
- Sara E Billings
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nina M Myers
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lee Quiruz
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alan G Cheng
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
12
|
Kaiser M, Wojahn I, Rudat C, Lüdtke TH, Christoffels VM, Moon A, Kispert A, Trowe MO. Regulation of otocyst patterning by Tbx2 and Tbx3 is required for inner ear morphogenesis in the mouse. Development 2021; 148:dev.195651. [PMID: 33795231 DOI: 10.1242/dev.195651] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 03/23/2021] [Indexed: 12/21/2022]
Abstract
All epithelial components of the inner ear, including sensory hair cells and innervating afferent neurons, arise by patterning and differentiation of epithelial progenitors residing in a simple sphere, the otocyst. Here, we identify the transcriptional repressors TBX2 and TBX3 as novel regulators of these processes in the mouse. Ablation of Tbx2 from the otocyst led to cochlear hypoplasia, whereas loss of Tbx3 was associated with vestibular malformations. The loss of function of both genes (Tbx2/3cDKO) prevented inner ear morphogenesis at midgestation, resulting in indiscernible cochlear and vestibular structures at birth. Morphogenetic impairment occurred concomitantly with increased apoptosis in ventral and lateral regions of Tbx2/3cDKO otocysts around E10.5. Expression analyses revealed partly disturbed regionalisation, and a posterior-ventral expansion of the neurogenic domain in Tbx2/3cDKO otocysts at this stage. We provide evidence that repression of FGF signalling by TBX2 is important to restrict neurogenesis to the anterior-ventral otocyst and implicate another T-box factor, TBX1, as a crucial mediator in this regulatory network.
Collapse
Affiliation(s)
- Marina Kaiser
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Irina Wojahn
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Carsten Rudat
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Timo H Lüdtke
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Vincent M Christoffels
- Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands
| | - Anne Moon
- Department of Molecular and Functional Genomics, Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA.,Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Andreas Kispert
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institute for Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| |
Collapse
|
13
|
van der Valk WH, Steinhart MR, Zhang J, Koehler KR. Building inner ears: recent advances and future challenges for in vitro organoid systems. Cell Death Differ 2020; 28:24-34. [PMID: 33318601 PMCID: PMC7853146 DOI: 10.1038/s41418-020-00678-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
While inner ear disorders are common, our ability to intervene and recover their sensory function is limited. In vitro models of the inner ear, like the organoid system, could aid in identifying new regenerative drugs and gene therapies. Here, we provide a perspective on the status of in vitro inner ear models and guidance on how to improve their applicability in translational research. We highlight the generation of inner ear cell types from pluripotent stem cells as a particularly promising focus of research. Several exciting recent studies have shown how the developmental signaling cues of embryonic and fetal development can be mimicked to differentiate stem cells into “inner ear organoids” containing otic progenitor cells, hair cells, and neurons. However, current differentiation protocols and our knowledge of embryonic and fetal inner ear development in general, have a bias toward the sensory epithelia of the inner ear. We propose that a more holistic view is needed to better model the inner ear in vitro. Moving forward, attention should be made to the broader diversity of neuroglial and mesenchymal cell types of the inner ear, and how they interact in space or time during development. With improved control of epithelial, neuroglial, and mesenchymal cell fate specification, inner ear organoids would have the ability to truly recapitulate neurosensory function and dysfunction. We conclude by discussing how single-cell atlases of the developing inner ear and technical innovations will be critical tools to advance inner ear organoid platforms for future pre-clinical applications.
Collapse
Affiliation(s)
- Wouter H van der Valk
- Department of Otorhinolaryngology and Head & Neck Surgery, Leiden University Medical Center, Leiden, Netherlands.,Department of Otolaryngology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Matthew R Steinhart
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.,Medical Neuroscience Graduate Program, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jingyuan Zhang
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA, 02115, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Karl R Koehler
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA, 02115, USA. .,Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA, 02115, USA. .,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, 02115, USA. .,Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA, 02115, USA.
| |
Collapse
|
14
|
Klein B, Pant S, Bhushan S, Kautz J, Rudat C, Kispert A, Pilatz A, Wijayarathna R, Middendorff R, Loveland KL, Hedger MP, Meinhardt A. Dexamethasone improves therapeutic outcomes in a preclinical bacterial epididymitis mouse model. Hum Reprod 2020; 34:1195-1205. [PMID: 31211847 DOI: 10.1093/humrep/dez073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/15/2019] [Accepted: 04/24/2019] [Indexed: 11/13/2022] Open
Abstract
STUDY QUESTION Can dexamethasone improve infertility-related cauda epididymidal tissue damage caused by bacterial epididymitis? SUMMARY ANSWER Dexamethasone in addition to anti-microbial treatment effectively reduces long-term deleterious epididymal tissue damage by dampening the host's adaptive immune response. WHAT IS KNOWN ALREADY Despite effective anti-microbial treatment, ~40% of patients with epididymitis experience subsequent sub- or infertility. An epididymitis mouse model has shown that the host immune response is mainly responsible for the magnitude of epididymal tissue damage that is fundamentally causative of the subsequent fertility issues. STUDY DESIGN, SIZE, DURATION Bacterial epididymitis was induced in male mice by using uropathogenic Escherichia coli (UPEC). From Day 3 after infection onwards, mice were treated with daily doses of levofloxacin (20 mg/kg, total n = 12 mice), dexamethasone (0.5 mg/kg, total n = 9) or both in combination (total n = 11) for seven consecutive days. Control animals were left untreated, i.e. given no interventional treatment following UPEC infection (total n = 11). Half of the animals from each group were killed either at 10 or 31 days post-infection. PARTICIPANTS/MATERIALS, SETTING, METHODS A mouse model of induced bacterial epididymitis was applied to adult male C57BL/6J mice. At the respective endpoints (10 or 31 days post-infection), epididymides were collected. Effectiveness of antibiotic treatment was assessed by plating of epididymal homogenates onto lysogeny broth agar plates. Overall tissue morphology and the degree and nature of tissue damage were assessed histologically. Quantitative RT-PCR was used to assess local cytokine transcript levels. Blood was drawn and serum analysed for systemic IgG and IgM levels by ELISA. In addition, correlation analyses of clinical data and serum-analyses of IgG and IgM levels in patients with epididymitis were performed. MAIN RESULTS AND THE ROLE OF CHANCE The addition of dexamethasone to the standard anti-microbial treatment did not further worsen epididymal tissue integrity. In fact, an obviously dampened immune response and reduced tissue reaction/damage was observed at both 10 and 31 days post-infection following combined treatment. More specifically, epididymal duct continuity was preserved, enabling sperm transit. In contrast, in untreated or antibiotic-treated animals, damage of the epididymal duct and duct constrictions were observed, associated with a lack of cauda spermatozoa. In line with the bacteriostatic/bactericidal effect of levofloxacin (alone as well as in combination), local cytokine transcript levels were significantly and similarly reduced in animals treated with levofloxacin alone (P < 0.01) or in combination with dexamethasone (P < 0.05) compared to UPEC-infected untreated animals. Interestingly, the addition of dexamethasone to the anti-microbial treatment induced a unique dampening effect on adaptive immunity, since systemic IgG and IgM levels as well as the pan-T cell marker CD3 were reduced at both 10 and 31 days post-infection. LIMITATIONS, REASONS FOR CAUTION Breeding studies to address the fertility-protecting effect of the combined treatment were not possible in the experimental animals because the vas deferens was ligated (model specific). WIDER IMPLICATIONS OF THE FINDINGS Whereas innate immunity is necessary and involved in acute bacterial clearance, adaptive immunity seems to be responsible for long-term, subclinical immunological activities that may negatively affect the pathogenesis of bacterial epididymitis even after effective bacterial eradication. These effects can be reduced in mice by the additional treatment with dexamethasone. This immunological characteristic of bacterial epididymitis shows similarities to the Jarisch-Herxheimer reaction known from other types of bacterial infection. STUDY FUNDING/COMPETING INTEREST(S) The study was supported by grants from the Deutsche Forschungsgemeinschaft, Monash University and the Medical Faculty of Justus-Liebig University to the International Research Training Group on 'Molecular pathogenesis of male reproductive disorders' (GRK 1871). R.W., K.L.L. and M.P.H. were supported by grants from the National Health and Medical Research Council of Australia (ID1079646, ID1081987, ID1020269 and ID1063843) and by the Victorian Government's Operational Infrastructure Support Program. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER No clinical trial involved.
Collapse
Affiliation(s)
- Britta Klein
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany
| | - Swapnila Pant
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany
| | - Sudhanshu Bhushan
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany
| | - Julia Kautz
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany
| | - Carsten Rudat
- Institute for Molecular Biology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Andreas Kispert
- Institute for Molecular Biology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Adrian Pilatz
- Department of Urology, Pediatric Urology and Andrology, Justus-Liebig University of Giessen, Germany
| | - Rukmali Wijayarathna
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Ralf Middendorff
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany
| | - Kate L Loveland
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia.,School of Clinical Sciences, Monash University, Clayton, VIC, Australia
| | - Mark P Hedger
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Andreas Meinhardt
- Institute of Anatomy and Cell Biology, Justus-Liebig University of Giessen, Giessen, Germany.,Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
| |
Collapse
|
15
|
Nyberg S, Abbott NJ, Shi X, Steyger PS, Dabdoub A. Delivery of therapeutics to the inner ear: The challenge of the blood-labyrinth barrier. Sci Transl Med 2020; 11:11/482/eaao0935. [PMID: 30842313 DOI: 10.1126/scitranslmed.aao0935] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 12/01/2017] [Accepted: 03/22/2018] [Indexed: 12/20/2022]
Abstract
Permanent hearing loss affects more than 5% of the world's population, yet there are no nondevice therapies that can protect or restore hearing. Delivery of therapeutics to the cochlea and vestibular system of the inner ear is complicated by their inaccessible location. Drug delivery to the inner ear via the vasculature is an attractive noninvasive strategy, yet the blood-labyrinth barrier at the luminal surface of inner ear capillaries restricts entry of most blood-borne compounds into inner ear tissues. Here, we compare the blood-labyrinth barrier to the blood-brain barrier, discuss invasive intratympanic and intracochlear drug delivery methods, and evaluate noninvasive strategies for drug delivery to the inner ear.
Collapse
Affiliation(s)
- Sophie Nyberg
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - N Joan Abbott
- Institute of Pharmaceutical Science, King's College London, London SE1 9NH, UK
| | - Xiaorui Shi
- Oregon Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Peter S Steyger
- Oregon Hearing Research Center, Department of Otolaryngology, Head & Neck Surgery, Oregon Health & Science University, Portland, OR 97239, USA
| | - Alain Dabdoub
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada. .,Department of Otolaryngology-Head & Neck Surgery, University of Toronto, Toronto, ON M5G 2C4, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5G 2C4, Canada
| |
Collapse
|
16
|
Miwa T, Minoda R, Ishikawa Y, Kajii T, Orita Y, Ohyama T. Role of Dach1 revealed using a novel inner ear-specific Dach1-knockdown mouse model. Biol Open 2019; 8:bio.043612. [PMID: 31405829 PMCID: PMC6737983 DOI: 10.1242/bio.043612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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 W, Schrott-Fischer A, Glueckert R, Benav H, Rask-Andersen H. The Human "Cochlear Battery" - Claudin-11 Barrier and Ion Transport Proteins in the Lateral Wall of the Cochlea. Front Mol Neurosci 2017; 10:239. [PMID: 28848383 PMCID: PMC5554435 DOI: 10.3389/fnmol.2017.00239] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/14/2017] [Indexed: 11/21/2022] Open
Abstract
Background: The cochlea produces an electric field potential essential for hair cell transduction and hearing. This biological “battery” is situated in the lateral wall of the cochlea and contains molecular machinery that secretes and recycles K+ ions. Its functioning depends on junctional proteins that restrict the para-cellular escape of ions. The tight junction protein Claudin-11 has been found to be one of the major constituents of this barrier that maintains ion gradients (Gow et al., 2004; Kitajiri et al., 2004a). We are the first to elucidate the human Claudin-11 framework and the associated ion transport machinery using super-resolution fluorescence illumination microscopy (SR-SIM). Methods: Archival cochleae obtained during meningioma surgery were used for SR-SIM together with transmission electron microscopy after ethical consent. Results: Claudin-11-expressing cells formed parallel tight junction lamellae that insulated the epithelial syncytium of the stria vascularis and extended to the suprastrial region. Intercellular gap junctions were found between the barrier cells and fibrocytes. Conclusion: Transmission electron microscopy, confocal microscopy and SR-SIM revealed exclusive cell specialization in the various subdomains of the lateral wall of the human cochlea. The Claudin-11-expressing cells exhibited both conductor and isolator characteristics, and these micro-porous separators may selectively mediate the movement of charged units to the intrastrial space in a manner that is analogous to a conventional electrochemical “battery.” The function and relevance of this battery for the development of inner ear disease are discussed.
Collapse
Affiliation(s)
- Wei Liu
- Department of Surgical Sciences, Section of Otolaryngology, Uppsala University HospitalUppsala, Sweden
| | | | - Rudolf Glueckert
- Department of Otolaryngology, Medical University of InnsbruckInnsbruck, Austria
| | | | - Helge Rask-Andersen
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University HospitalUppsala, Sweden
| |
Collapse
|
18
|
Hepatocyte Growth Factor-c-MET Signaling Mediates the Development of Nonsensory Structures of the Mammalian Cochlea and Hearing. J Neurosci 2017; 36:8200-9. [PMID: 27488639 DOI: 10.1523/jneurosci.4410-15.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 06/28/2016] [Indexed: 12/28/2022] Open
Abstract
UNLABELLED The stria vascularis is a nonsensory structure that is essential for auditory hair cell function by maintaining potassium concentration of the scala media. During mouse embryonic development, a subpopulation of neural crest cell-derived melanocytes migrates and incorporates into a subregion of the cochlear epithelium, forming the intermediate cell layer of the stria vascularis. The relation of this developmental process to stria vascularis function is currently unknown. In characterizing the molecular differentiation of developing peripheral auditory structures, we discovered that hepatocyte growth factor (Hgf) is expressed in the future stria vascularis of the cochlear epithelium. Its receptor tyrosine kinase, c-Met, is expressed in the cochlear epithelium and melanocyte-derived intermediate cells in the stria vascularis. Genetic dissection of HGF signaling via c-MET reveals that the incorporation of the melanocytes into the future stria vascularis of the cochlear duct requires c-MET signaling. In addition, inactivation of either the ligand or receptor developmentally resulted in a profound hearing loss at young adult stages. These results suggest a novel connection between HGF signaling and deafness via melanocyte deficiencies. SIGNIFICANCE STATEMENT We found the roles of hepatocyte growth factor (HGF) signaling in stria vascularis development for the first time and that lack of HGF signaling in the inner ear leads to profound hearing loss in the mouse. Our findings reveal a novel mechanism that may underlie human deafness DFNB39 and DFNB97. Our findings reveal an additional example of context-dependent c-MET signaling diversity, required here for proper cellular invasion developmentally that is essential for specific aspects of auditory-related organogenesis.
Collapse
|
19
|
Bohnenpoll T, Feraric S, Nattkemper M, Weiss AC, Rudat C, Meuser M, Trowe MO, Kispert A. Diversification of Cell Lineages in Ureter Development. J Am Soc Nephrol 2016; 28:1792-1801. [PMID: 28028137 DOI: 10.1681/asn.2016080849] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 11/08/2016] [Indexed: 02/06/2023] Open
Abstract
The mammalian ureter consists of a mesenchymal wall composed of smooth muscle cells and surrounding fibrocytes of the tunica adventitia and the lamina propria and an inner epithelial lining composed of layers of basal, intermediate, and superficial cells. How these cell types arise from multipotent progenitors is poorly understood. Here, we performed marker analysis, cell proliferation assays, and genetic lineage tracing to define the lineage relations and restrictions of the mesenchymal and epithelial cell types in the developing and mature mouse ureter. At embryonic day (E) 12.5, the mesenchymal precursor pool began to subdivide into an inner and outer compartment that began to express markers of smooth muscle precursors and adventitial fibrocytes, respectively, by E13.5. Smooth muscle precursors further diversified into lamina propria cells directly adjacent to the ureteric epithelium and differentiated smooth muscle cells from E16.5 onwards. Uncommitted epithelial progenitors of the ureter differentiated into intermediate cells at E14.5. After stratification into two layers at E15.5 and three cell layers at E18.5, intermediate cells differentiated into basal cells and superficial cells. In homeostasis, proliferation of all epithelial and mesenchymal cell types remained low but intermediate cells still gave rise to basal cells, whereas basal cells divided only into basal cells. These studies provide a framework to further determine the molecular mechanisms of cell differentiation in the tissues of the developing ureter.
Collapse
Affiliation(s)
- Tobias Bohnenpoll
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Sarah Feraric
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Marvin Nattkemper
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Anna-Carina Weiss
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Carsten Rudat
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Max Meuser
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Mark-Oliver Trowe
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Andreas Kispert
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, Hannover, Germany
| |
Collapse
|
20
|
Weiss AC, Airik R, Bohnenpoll T, Greulich F, Foik A, Trowe MO, Rudat C, Costantini F, Adams RH, Kispert A. Nephric duct insertion requires EphA4/EphA7 signaling from the pericloacal mesenchyme. Development 2014; 141:3420-30. [DOI: 10.1242/dev.113928] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The vesico-ureteric junction (VUJ) forms through a complex developmental program that connects the primordium of the upper urinary tract [the nephric duct (ND)] with that of the lower urinary tract (the cloaca). The signals that orchestrate the various tissue interactions in this program are poorly understood. Here, we show that two members of the EphA subfamily of receptor tyrosine kinases, EphA4 and EphA7, are specifically expressed in the mesenchyme surrounding the caudal ND and the cloaca, and that Epha4−/−;Epha7+/− and Epha4−/−;Epha7−/− (DKO) mice display distal ureter malformations including ureterocele, blind and ectopically ending ureters with associated hydroureter, megaureter and hydronephrosis. We trace these defects to a late or absent fusion of the ND with the cloaca. In DKO embryos, the ND extends normally and approaches the cloaca but the tip subsequently looses its integrity. Expression of Gata3 and Lhx1 and their downstream target Ret is severely reduced in the caudal ND. Conditional deletion of ephrin B2 from the ND largely phenocopies these changes, suggesting that EphA4/EphA7 from the pericloacal mesenchyme signal via ephrin B2 to mediate ND insertion. Disturbed activity of this signaling module may entail defects of the VUJ, which are frequent in the spectrum of congenital anomalies of the kidney and the urinary tract (CAKUT) in human newborns.
Collapse
Affiliation(s)
- Anna-Carina Weiss
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Rannar Airik
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Tobias Bohnenpoll
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Franziska Greulich
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Anna Foik
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Carsten Rudat
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Frank Costantini
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Ralf H. Adams
- Max-Planck-Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, andUniversity of Münster, Faculty of Medicine, D-48149 Münster, Germany
| | - Andreas Kispert
- Institut für Molekularbiologie, Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| |
Collapse
|
21
|
Bohnenpoll T, Trowe MO, Wojahn I, Taketo MM, Petry M, Kispert A. Canonical Wnt signaling regulates the proliferative expansion and differentiation of fibrocytes in the murine inner ear. Dev Biol 2014; 391:54-65. [PMID: 24727668 DOI: 10.1016/j.ydbio.2014.03.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/27/2014] [Accepted: 03/29/2014] [Indexed: 01/18/2023]
Abstract
Otic fibrocytes tether the cochlear duct to the surrounding otic capsule but are also critically involved in maintenance of ion homeostasis in the cochlea, thus, perception of sound. The molecular pathways that regulate the development of this heterogenous group of cells from mesenchymal precursors are poorly understood. Here, we identified epithelial Wnt7a and Wnt7b as possible ligands of Fzd-mediated β-catenin (Ctnnb1)-dependent (canonical) Wnt signaling in the adjacent undifferentiated periotic mesenchyme (POM). Mice with a conditional deletion of Ctnnb1 in the POM exhibited a complete failure of fibrocyte differentiation, a severe reduction of mesenchymal cells surrounding the cochlear duct, loss of pericochlear spaces, a thickening and partial loss of the bony capsule and a secondary disturbance of cochlear duct coiling shortly before birth. Analysis at earlier stages revealed that radial patterning of the POM in two domains with highly condensed cartilaginous precursors and more loosely arranged inner mesenchymal cells occurred normally but that proliferation in the inner domain was reduced and cytodifferentiation failed. Cells with mis/overexpression of a stabilized form of Ctnnb1 in the entire POM mesenchyme sorted to the inner mesenchymal compartment and exhibited increased proliferation. Our analysis suggests that Wnt signals from the cochlear duct epithelium are crucial to induce differentiation and expansion of fibrocyte precursor cells. Our findings emphasize the importance of epithelial-mesenchymal signaling in inner ear development.
Collapse
Affiliation(s)
- Tobias Bohnenpoll
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Irina Wojahn
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | | | - Marianne Petry
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Andreas Kispert
- Institut für Molekularbiologie, OE5250, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
| |
Collapse
|
22
|
Saremi A, Stenfelt S. Effect of metabolic presbyacusis on cochlear responses: a simulation approach using a physiologically-based model. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2013; 134:2833-2851. [PMID: 24116421 DOI: 10.1121/1.4820788] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the presented model, electrical, acoustical, and mechanical elements of the cochlea are explicitly integrated into a signal transmission line where these elements convey physiological interpretations of the human cochlear structures. As a result, this physiologically-motivated model enables simulation of specific cochlear lesions such as presbyacusis. The hypothesis is that high-frequency hearing loss in older adults may be due to metabolic presbyacusis whereby age-related cellular/chemical degenerations in the lateral wall of the cochlea cause a reduction in the endocochlear potential. The simulations quantitatively confirm this hypothesis and emphasize that even if the outer and inner hair cells are totally active and intact, metabolic presbyacusis alone can significantly deteriorate the cochlear functionality. Specifically, in the model, as the endocochlear potential decreases, the transduction mechanism produces less receptor current such that there is a reduction in the battery of the somatic motor. This leads to a drastic decrease in cochlear amplification and frequency sensitivity, as well as changes in position-frequency map (tuning pattern) of the cochlea. In addition, the simulations show that the age-related reduction of the endocochlear potential significantly inhibits the firing rate of the auditory nerve which might contribute to the decline of temporal resolution in the aging auditory system.
Collapse
MESH Headings
- Action Potentials
- Age Factors
- Aging/metabolism
- Animals
- Cochlea/metabolism
- Cochlea/pathology
- Cochlea/physiopathology
- Cochlear Nerve/metabolism
- Cochlear Nerve/physiopathology
- Computer Simulation
- Evoked Potentials
- Hair Cells, Auditory, Inner/metabolism
- Hair Cells, Auditory, Inner/pathology
- Hair Cells, Auditory, Outer/metabolism
- Hair Cells, Auditory, Outer/pathology
- Hearing
- Humans
- Linear Models
- Mechanotransduction, Cellular
- Models, Biological
- Nonlinear Dynamics
- Presbycusis/metabolism
- Presbycusis/pathology
- Presbycusis/physiopathology
- Pressure
- Time Factors
- Vibration
Collapse
Affiliation(s)
- Amin Saremi
- Department of Clinical and Experimental Medicine, Division of Technical Audiology, Linköping University, 581 85 Linköping, Sweden
| | | |
Collapse
|
23
|
Zhang F, Dai M, Neng L, Zhang JH, Zhi Z, Fridberger A, Shi X. Perivascular macrophage-like melanocyte responsiveness to acoustic trauma--a salient feature of strial barrier associated hearing loss. FASEB J 2013; 27:3730-40. [PMID: 23729595 DOI: 10.1096/fj.13-232892] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Tissue perivascular resident macrophages (PVM/Ms), a hybrid cell type with characteristics of both macrophages and melanocytes, are critical for establishing and maintaining the endocochlear potential (EP) required for hearing. The PVM/Ms modulate expression of tight- and adherens-junction proteins in the endothelial barrier of the stria vascularis (intrastrial fluid-blood barrier) through secretion of a signaling molecule, pigment epithelium growth factor (PEDF). Here, we identify a significant link between abnormalities in PVM/Ms and endothelial barrier breakdown from acoustic trauma to the mouse ear. We find that acoustic trauma causes activation of PVM/Ms and physical detachment from capillary walls. Concurrent with the detachment, we find loosened tight junctions between endothelial cells and decreased production of tight- and adherens-junction protein, resulting in leakage of serum proteins from the damaged barrier. A key factor in the intrastrial fluid-blood barrier hyperpermeability exhibited in the mice is down-regulation of PVM/M modulated PEDF production. We demonstrate that delivery of PEDF to the damaged ear ameliorates hearing loss by restoring intrastrial fluid-blood barrier integrity. PEDF up-regulates expression of tight junction-associated proteins (ZO-1 and VE-cadherin) and PVM/M stabilizing neural cell adhesion molecule (NCAM-120). These studies point to the critical role PVM/Ms play in regulating intrastrial fluid-blood barrier integrity in healthy and noise-damaged ears.
Collapse
Affiliation(s)
- Fei Zhang
- Oregon Hearing Research Center, Department of Otolaryngology/Head and Neck Surgery, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Lorente-Cánovas B, Ingham N, Norgett EE, Golder ZJ, Karet Frankl FE, Steel KP. Mice deficient in H+-ATPase a4 subunit have severe hearing impairment associated with enlarged endolymphatic compartments within the inner ear. Dis Model Mech 2012; 6:434-42. [PMID: 23065636 PMCID: PMC3597025 DOI: 10.1242/dmm.010645] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mutations in the ATP6V0A4 gene lead to autosomal recessive distal renal tubular acidosis in patients, who often show sensorineural hearing impairment. A first Atp6v0a4 knockout mouse model that recapitulates the loss of H+-ATPase function seen in humans has been generated and recently reported (Norgett et al., 2012). Here, we present the first detailed analysis of the structure and function of the auditory system in Atp6v0a4−/− knockout mice. Measurements of the auditory brainstem response (ABR) showed significantly elevated thresholds in homozygous mutant mice, which indicate severe hearing impairment. Heterozygote thresholds were normal. Analysis of paint-filled inner ears and sections from E16.5 embryos revealed a marked expansion of cochlear and endolymphatic ducts in Atp6v0a4−/− mice. A regulatory link between Atp6v0a4, Foxi1 and Pds has been reported and we found that the endolymphatic sac of Atp6v0a4−/− mice expresses both Foxi1 and Pds, which suggests a downstream position of Atp6v0a4. These mutants also showed a lack of endocochlear potential, suggesting a functional defect of the stria vascularis on the lateral wall of the cochlear duct. However, the main K+ channels involved in the generation of endocochlear potential, Kcnj10 and Kcnq1, are strongly expressed in Atp6v0a4−/− mice. Our results lead to a better understanding of the role of this proton pump in hearing function.
Collapse
|