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Wang S, Chakraborty S, Fu Y, Lee MP, Liu J, Waldhaus J. 3D reconstruction of the mouse cochlea from scRNA-seq data suggests morphogen-based principles in apex-to-base specification. Dev Cell 2024; 59:1538-1552.e6. [PMID: 38593801 PMCID: PMC11187690 DOI: 10.1016/j.devcel.2024.03.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 04/03/2023] [Accepted: 03/13/2024] [Indexed: 04/11/2024]
Abstract
In the mammalian auditory system, frequency discrimination depends on numerous morphological and physiological properties of the organ of Corti, which gradually change along the apex-to-base (tonotopic) axis of the organ. For example, the basilar membrane stiffness changes tonotopically, thus affecting the tuning properties of individual hair cells. At the molecular level, those frequency-specific characteristics are mirrored by gene expression gradients; however, the molecular mechanisms controlling tonotopic gene expression in the mouse cochlea remain elusive. Through analyzing single-cell RNA sequencing (scRNA-seq) data from E12.5 and E14.5 time points, we predicted that morphogens, rather than a cell division-associated mechanism, confer spatial identity in the extending cochlea. Subsequently, we reconstructed the developing cochlea in 3D space from scRNA-seq data to investigate the molecular pathways mediating positional information. The retinoic acid (RA) and hedgehog pathways were found to form opposing apex-to-base gradients, and functional interrogation using mouse cochlear explants suggested that both pathways jointly specify the longitudinal axis.
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Affiliation(s)
- Shuze Wang
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Saikat Chakraborty
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yujuan Fu
- Biomedical Informatics and Medical Education, University of Washington, Seattle, WA 98195, USA
| | - Mary P Lee
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jie Liu
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Joerg Waldhaus
- Department of Otolaryngology-Head and Neck Surgery, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA.
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2
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Sosa J, Oyelakin A, Sinha S. The Reign of Follistatin in Tumors and Their Microenvironment: Implications for Drug Resistance. BIOLOGY 2024; 13:130. [PMID: 38392348 PMCID: PMC10887188 DOI: 10.3390/biology13020130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/10/2024] [Accepted: 02/16/2024] [Indexed: 02/24/2024]
Abstract
Follistatin (FST) is a potent neutralizer of the transforming growth factor-β superfamily and is associated with normal cellular programs and various hallmarks of cancer, such as proliferation, migration, angiogenesis, and immune evasion. The aberrant expression of FST by solid tumors is a well-documented observation, yet how FST influences tumor progression and therapy response remains unclear. The recent surge in omics data has revealed new insights into the molecular foundation underpinning tumor heterogeneity and its microenvironment, offering novel precision medicine-based opportunities to combat cancer. In this review, we discuss these recent FST-centric studies, thereby offering an updated perspective on the protean role of FST isoforms in shaping the complex cellular ecosystem of tumors and in mediating drug resistance.
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Affiliation(s)
- Jennifer Sosa
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Akinsola Oyelakin
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle Children's Hospital, Seattle, WA 98101, USA
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle Children's Hospital, Seattle, WA 98101, USA
| | - Satrajit Sinha
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
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3
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Sun Y, Liu Z. Recent advances in molecular studies on cochlear development and regeneration. Curr Opin Neurobiol 2023; 81:102745. [PMID: 37356371 DOI: 10.1016/j.conb.2023.102745] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/06/2023] [Accepted: 05/25/2023] [Indexed: 06/27/2023]
Abstract
The auditory organ cochlea harbors two types of sound receptors, inner hair cells (IHCs) and outer hair cells (OHCs), which are innervated by spiral (auditory) ganglion neurons (SGNs). Recent transcriptomic, epigenetic, and genetic studies have started to reveal various aspects of cochlear development, including how prosensory progenitors are specified and diversified into IHCs or OHCs, as well as the heterogeneity among SGNs and how SGN subtypes are formed. Here, we primarily review advances in this line of research over the past five years and discuss a few key studies (from the past two years) to elucidate (1) how prosensory progenitors are specified; (2) the cis-regulatory control of Atoh1 expression and the synergistic interaction between Atoh1 and Pou4f3; and (3) the essential roles of Insm1 and Ikzf2 in OHC development and Tbx2 in IHC development. Moreover, we highlight the contribution of recent molecular studies on cochlear development toward the goal of regenerating IHCs and OHCs, which holds considerable potential for application in treating human deafness. Lastly, we briefly summarize the most recent progress on uncovering when and how SGN diversity is generated.
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Affiliation(s)
- Yuwei Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zhiyong Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
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4
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Maunsell HR, Ellis K, Kelley MW, Driver EC. Lrrn1 Regulates Medial Boundary Formation in the Developing Mouse Organ of Corti. J Neurosci 2023; 43:5305-5318. [PMID: 37369584 PMCID: PMC10359035 DOI: 10.1523/jneurosci.2141-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/12/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023] Open
Abstract
One of the most striking aspects of the sensory epithelium of the mammalian cochlea, the organ of Corti (OC), is the presence of precise boundaries between sensory and nonsensory cells at its medial and lateral edges. A particular example of this precision is the single row of inner hair cells (IHCs) and associated supporting cells along the medial (neural) boundary. Despite the regularity of this boundary, the developmental processes and genetic factors that contribute to its specification are poorly understood. In this study we demonstrate that Leucine Rich Repeat Neuronal 1 (Lrrn1), which codes for a single-pass, transmembrane protein, is expressed before the development of the mouse organ of Corti in the row of cells that will form its medial border. Deletion of Lrrn1 in mice of mixed sex leads to disruptions in boundary formation that manifest as ectopic inner hair cells and supporting cells. Genetic and pharmacological manipulations demonstrate that Lrrn1 interacts with the Notch signaling pathway and strongly suggest that Lrrn1 normally acts to enhance Notch signaling across the medial boundary. This interaction is required to promote formation of the row of inner hair cells and suppress the conversion of adjacent nonsensory cells into hair cells and supporting cells. These results identify Lrrn1 as an important regulator of boundary formation and cellular patterning during development of the organ of Corti.SIGNIFICANCE STATEMENT Patterning of the developing mammalian cochlea into distinct sensory and nonsensory regions and the specification of multiple different cell fates within those regions are critical for proper auditory function. Here, we report that the transmembrane protein Leucine Rich Repeat Neuronal 1 (LRRN1) is expressed along the sharp medial boundary between the single row of mechanosensory inner hair cells (IHCs) and adjacent nonsensory cells. Formation of this boundary is mediated in part by Notch signaling, and loss of Lrrn1 leads to disruptions in boundary formation similar to those caused by a reduction in Notch activity, suggesting that LRRN1 likely acts to enhance Notch signaling. Greater understanding of sensory/nonsensory cell fate decisions in the cochlea will help inform the development of regenerative strategies aimed at restoring auditory function.
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Affiliation(s)
- Helen R Maunsell
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Kathryn Ellis
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Matthew W Kelley
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Elizabeth Carroll Driver
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
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5
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Fettiplace R. Cochlear tonotopy from proteins to perception. Bioessays 2023:e2300058. [PMID: 37329318 DOI: 10.1002/bies.202300058] [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: 03/31/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
A ubiquitous feature of the auditory organ in amniotes is the longitudinal mapping of neuronal characteristic frequencies (CFs), which increase exponentially with distance along the organ. The exponential tonotopic map reflects variation in hair cell properties according to cochlear location and is thought to stem from concentration gradients in diffusible morphogenic proteins during embryonic development. While in all amniotes the spatial gradient is initiated by sonic hedgehog (SHH), released from the notochord and floorplate, subsequent molecular pathways are not fully understood. In chickens, BMP7 is one such morphogen, secreted from the distal end of the cochlea. In mammals, the developmental mechanism differs from birds and may depend on cochlear location. A consequence of exponential maps is that each octave occupies an equal distance on the cochlea, a spacing preserved in the tonotopic maps in higher auditory brain regions. This may facilitate frequency analysis and recognition of acoustic sequences.
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Affiliation(s)
- Robert Fettiplace
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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Thompson MJ, Young CA, Munnamalai V, Umulis DM. Early radial positional information in the cochlea is optimized by a precise linear BMP gradient and enhanced by SOX2. Sci Rep 2023; 13:8567. [PMID: 37237002 PMCID: PMC10219982 DOI: 10.1038/s41598-023-34725-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023] Open
Abstract
Positional information encoded in signaling molecules is essential for early patterning in the prosensory domain of the developing cochlea. The sensory epithelium, the organ of Corti, contains an exquisite repeating pattern of hair cells and supporting cells. This requires precision in the morphogen signals that set the initial radial compartment boundaries, but this has not been investigated. To measure gradient formation and morphogenetic precision in developing cochlea, we developed a quantitative image analysis procedure measuring SOX2 and pSMAD1/5/9 profiles in mouse embryos at embryonic day (E)12.5, E13.5, and E14.5. Intriguingly, we found that the pSMAD1/5/9 profile forms a linear gradient up to the medial ~ 75% of the PSD from the pSMAD1/5/9 peak in the lateral edge during E12.5 and E13.5. This is a surprising activity readout for a diffusive BMP4 ligand secreted from a tightly constrained lateral region since morphogens typically form exponential or power-law gradient shapes. This is meaningful for gradient interpretation because while linear profiles offer the theoretically highest information content and distributed precision for patterning, a linear morphogen gradient has not yet been observed. Furthermore, this is unique to the cochlear epithelium as the pSMAD1/5/9 gradient is exponential in the surrounding mesenchyme. In addition to the information-optimized linear profile, we found that while pSMAD1/5/9 is stable during this timeframe, an accompanying gradient of SOX2 shifts dynamically. Last, through joint decoding maps of pSMAD1/5/9 and SOX2, we see that there is a high-fidelity mapping between signaling activity and position in the regions that will become Kölliker's organ and the organ of Corti. Mapping is ambiguous in the prosensory domain precursory to the outer sulcus. Altogether, this research provides new insights into the precision of early morphogenetic patterning cues in the radial cochlea prosensory domain.
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Affiliation(s)
- Matthew J Thompson
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, USA
| | - Caryl A Young
- University of Maine, 168 College Ave, Orono, ME, 04469, USA
| | - Vidhya Munnamalai
- University of Maine, 168 College Ave, Orono, ME, 04469, USA.
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
| | - David M Umulis
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN, 47907, USA.
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7
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Follistatin regulates the specification of the apical cochlea responsible for low-frequency hearing in mammals. Proc Natl Acad Sci U S A 2023; 120:e2213099120. [PMID: 36577057 PMCID: PMC9910458 DOI: 10.1073/pnas.2213099120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The cochlea's ability to discriminate sound frequencies is facilitated by a special topography along its longitudinal axis known as tonotopy. Auditory hair cells located at the base of the cochlea respond to high-frequency sounds, whereas hair cells at the apex respond to lower frequencies. Gradual changes in morphological and physiological features along the length of the cochlea determine each region's frequency selectivity, but it remains unclear how tonotopy is established during cochlear development. Recently, sonic hedgehog (SHH) was proposed to initiate the establishment of tonotopy by conferring regional identity to the primordial cochlea. Here, using mouse genetics, we provide in vivo evidence that regional identity in the embryonic cochlea acts as a framework upon which tonotopy-specific properties essential for frequency selectivity in the mature cochlea develop. We found that follistatin (FST) is required for the maintenance of apical cochlear identity, but dispensable for its initial induction. In a fate-mapping analysis, we found that FST promotes expansion of apical cochlear cells, contributing to the formation of the apical cochlear domain. SHH, in contrast, is required both for the induction and maintenance of apical identity. In the absence of FST or SHH, mice produce a short cochlea lacking its apical domain. This results in the loss of apex-specific anatomical and molecular properties and low-frequency-specific hearing loss.
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8
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Heuermann ML, Matos S, Hamilton D, Cox BC. Regenerated hair cells in the neonatal cochlea are innervated and the majority co-express markers of both inner and outer hair cells. Front Cell Neurosci 2022; 16:841864. [PMID: 36187289 PMCID: PMC9524252 DOI: 10.3389/fncel.2022.841864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 08/29/2022] [Indexed: 11/30/2022] Open
Abstract
After a damaging insult, hair cells can spontaneously regenerate from cochlear supporting cells within the first week of life. While the regenerated cells express several markers of immature hair cells and have stereocilia bundles, their capacity to differentiate into inner or outer hair cells, and ability to form new synaptic connections has not been well-described. In addition, while multiple supporting cell subtypes have been implicated as the source of the regenerated hair cells, it is unclear if certain subtypes have a greater propensity to form one hair cell type over another. To investigate this, we used two CreER mouse models to fate-map either the supporting cells located near the inner hair cells (inner phalangeal and border cells) or outer hair cells (Deiters’, inner pillar, and outer pillar cells) along with immunostaining for markers that specify the two hair cell types. We found that supporting cells fate-mapped by both CreER lines responded early to hair cell damage by expressing Atoh1, and are capable of producing regenerated hair cells that express terminal differentiation markers of both inner and outer hair cells. The majority of regenerated hair cells were innervated by neuronal fibers and contained synapses. Unexpectedly, we also found that the majority of the laterally positioned regenerated hair cells aberrantly expressed both the outer hair cell gene, oncomodulin, and the inner hair cell gene, vesicular glutamate transporter 3 (VGlut3). While this work demonstrates that regenerated cells can express markers of both inner and outer hair cells after damage, VGlut3 expression appears to lack the tight control present during embryogenesis, which leads to its inappropriate expression in regenerated cells.
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Affiliation(s)
- Mitchell L. Heuermann
- Department of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Sophia Matos
- Department of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Deborah Hamilton
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
| | - Brandon C. Cox
- Department of Otolaryngology, Southern Illinois University School of Medicine, Springfield, IL, United States
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, United States
- *Correspondence: Brandon C. Cox,
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9
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Kelley MW. Cochlear Development; New Tools and Approaches. Front Cell Dev Biol 2022; 10:884240. [PMID: 35813214 PMCID: PMC9260282 DOI: 10.3389/fcell.2022.884240] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 05/19/2022] [Indexed: 12/21/2022] Open
Abstract
The sensory epithelium of the mammalian cochlea, the organ of Corti, is comprised of at least seven unique cell types including two functionally distinct types of mechanosensory hair cells. All of the cell types within the organ of Corti are believed to develop from a population of precursor cells referred to as prosensory cells. Results from previous studies have begun to identify the developmental processes, lineage restrictions and signaling networks that mediate the specification of many of these cell types, however, the small size of the organ and the limited number of each cell type has hampered progress. Recent technical advances, in particular relating to the ability to capture and characterize gene expression at the single cell level, have opened new avenues for understanding cellular specification in the organ of Corti. This review will cover our current understanding of cellular specification in the cochlea, discuss the most commonly used methods for single cell RNA sequencing and describe how results from a recent study using single cell sequencing provided new insights regarding cellular specification.
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10
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Li XJ, Morgan C, Goff LA, Doetzlhofer A. Follistatin promotes LIN28B-mediated supporting cell reprogramming and hair cell regeneration in the murine cochlea. SCIENCE ADVANCES 2022; 8:eabj7651. [PMID: 35148175 PMCID: PMC8836811 DOI: 10.1126/sciadv.abj7651] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 12/18/2021] [Indexed: 05/27/2023]
Abstract
Hair cell (HC) loss within the inner ear cochlea is a leading cause for deafness in humans. Before the onset of hearing, immature supporting cells (SCs) in neonatal mice have some limited capacity for HC regeneration. Here, we show that in organoid culture, transient activation of the progenitor-specific RNA binding protein LIN28B and Activin antagonist follistatin (FST) enhances regenerative competence of maturing/mature cochlear SCs by reprogramming them into progenitor-like cells. Transcriptome profiling and mechanistic studies reveal that LIN28B drives SC reprogramming, while FST is required to counterbalance hyperactivation of transforming growth factor-β-type signaling by LIN28B. Last, we show that LIN28B and FST coactivation enhances spontaneous cochlear HC regeneration in neonatal mice and that LIN28B may be part of an endogenous repair mechanism that primes SCs for HC regeneration. These findings indicate that SC dedifferentiation is critical for HC regeneration and identify LIN28B and FST as main regulators.
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Affiliation(s)
- Xiao-Jun Li
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Charles Morgan
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Loyal A. Goff
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Angelika Doetzlhofer
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Otolaryngology and Center for Hearing and Balance, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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11
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Cochlear development, cellular patterning and tonotopy. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Wang L, Kempton JB, Jiang H, Jodelka FM, Brigande AM, Dumont RA, Rigo F, Lentz JJ, Hastings ML, Brigande JV. Fetal antisense oligonucleotide therapy for congenital deafness and vestibular dysfunction. Nucleic Acids Res 2020; 48:5065-5080. [PMID: 32249312 PMCID: PMC7229850 DOI: 10.1093/nar/gkaa194] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/13/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.
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Affiliation(s)
- Lingyan Wang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - J Beth Kempton
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Han Jiang
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Francine M Jodelka
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Alev M Brigande
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Rachel A Dumont
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010 USA
| | - Jennifer J Lentz
- Department of Otorhinolaryngology, Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Michelle L Hastings
- Center for Genetic Diseases, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - John V Brigande
- Department of Otolaryngology, Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR 97239, USA
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13
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Follistatin expression in the central nervous system of the adult rat. J Chem Neuroanat 2020; 105:101753. [PMID: 32014555 DOI: 10.1016/j.jchemneu.2020.101753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/30/2020] [Accepted: 01/30/2020] [Indexed: 11/21/2022]
Abstract
Follistatin was initially cloned as a monomeric polypeptide that inhibits the release of follicle-stimulating hormone. Although follistatin also plays pivotal roles in skeletal muscle hypertrophy and immunoregulation in the epididymis, little information is available regarding follistatin function in the adult central nervous system (CNS). Hence, we investigated follistatin expression in the adult rat CNS using immunohistochemistry. Follistatin was intensely expressed in most neurons and their axons. Furthermore, oligodendrocytes, ependymal cells, and some astrocytes also expressed follistatin protein. These data indicate that follistatin is widely expressed throughout the adult CNS. The abundant expression of follistatin in the adult brain suggests that this protein plays important roles in the CNS.
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14
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Munnamalai V, Fekete DM. The acquisition of positional information across the radial axis of the cochlea. Dev Dyn 2019; 249:281-297. [PMID: 31566832 DOI: 10.1002/dvdy.118] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Vidhya Munnamalai
- The Jackson Laboratory Bar Harbor Maine
- Graduate Program of Biomedical Sciences and EngineeringUniversity of Maine Orono Maine
- The Neuroscience ProgramSackler School of Biomedical Sciences, Tufts University Boston Massachusetts
| | - Donna M. Fekete
- Department of Biological SciencesPurdue University West Lafayette Indiana
- Purdue Institute for Integrative Neuroscience West Lafayette Indiana
- Purdue Center for Cancer Research West Lafayette Indiana
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