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Li J, Huang Y, Yang X, Cai Y, Wang Y, Dai W, Jiang L, Wang C, Wen Z. Tyrosine-phosphorylated DNER sensitizes insulin signaling in hepatic gluconeogenesis by inducing proteasomal degradation of TRB3. Mol Metab 2024; 83:101927. [PMID: 38553003 PMCID: PMC10999696 DOI: 10.1016/j.molmet.2024.101927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
OBJECTIVE Hepatic insulin resistance, which leads to increased hepatic gluconeogenesis, is a major contributor to fasting hyperglycemia in type 2 diabetes mellitus (T2DM). However, the mechanism of impaired insulin-dependent suppression of hepatic gluconeogenesis remains elusive. Delta/Notch-like epidermal growth factor (EGF)-related receptor (DNER), firstly described as a neuron-specific Notch ligand, has been recently identified as a susceptibility gene for T2DM through genome-wide association studies. We herein investigated whether DNER regulates hepatic gluconeogenesis and whether this is mediated by enhanced insulin signaling. METHODS The association between DNER, tribbles homolog 3 (TRB3) and Akt signaling was evaluated in C57BL/6J, ob/ob and db/db mice by western blot analysis. DNER loss-of-function and gain-of-function in hepatic gluconeogenesis were analyzed by western blot analysis, quantitative real-time PCR, glucose uptake and output assay in AML-12 cells and partially validated in primary mouse hepatocytes. Hepatic DNER knockdown mice were generated by tail vein injection of adenovirus to confirm the effects of DNER in vivo. The interaction between DNER and TRB3 was investigated by rescue experiments, cycloheximide chase analysis, co-immunoprecipitation and immunofluorescence. The potential insulin-stimulated phosphorylation sites of DNER were determined by co-immunoprecipitation, LC-MS/MS analysis and site-specific mutagenesis. RESULTS Here we show that DNER enhanced hepatic insulin signaling in gluconeogenesis by inhibiting TRB3, an endogenous Akt inhibitor, through the ubiquitin-proteasome degradation pathway. In AML-12 hepatocytes, insulin-stimulated activation of Akt and suppression of gluconeogenesis are attenuated by DNER knockdown, but potentiated by DNER over-expression. In C57BL/6J mice, hepatic DNER knockdown is accompanied by impaired glucose and pyruvate tolerance. Furthermore, the in vitro effects of DNER knockdown or over-expression on both Akt activity and hepatic gluconeogenesis can be rescued by TRB3 knockdown or over-expression, respectively. In response to insulin stimulation, DNER interacted directly with insulin receptor and was phosphorylated at Tyr677. This site-specific phosphorylation is essential for DNER to upregulate Akt activity and then downregulate G6Pase and PEPCK expression, by interacting with TRB3 directly and inducing TRB3 proteasome-dependent degradation. CONCLUSIONS Taken together, the crosstalk between insulin-Akt and DNER-TRB3 pathways represents a previously unrecognized mechanism by which insulin regulates hepatic gluconeogenesis.
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Affiliation(s)
- Junfeng Li
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Yan Huang
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Xinyu Yang
- Department of Pathology & Pathophysiology, Wuhan University School of Basic Medical Sciences, Wuhan 430071, China
| | - Yuli Cai
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Ye Wang
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Wenling Dai
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Liu Jiang
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Changhua Wang
- Department of Pathology & Pathophysiology, Wuhan University School of Basic Medical Sciences, Wuhan 430071, China
| | - Zhongyuan Wen
- Department of Endocrinology, Renmin Hospital of Wuhan University, Wuhan 430060, China
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Gross J, Knipper M, Mazurek B. Candidate Key Proteins in Tinnitus: A Bioinformatic Study of Synaptic Transmission in Spiral Ganglion Neurons. Cell Mol Neurobiol 2023; 43:4189-4207. [PMID: 37736859 PMCID: PMC10661836 DOI: 10.1007/s10571-023-01405-w] [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: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/23/2023]
Abstract
To study key proteins associated with changes in synaptic transmission in the spiral ganglion in tinnitus, we build three gene lists from the GeneCard database: 1. Perception of sound (PoS), 2. Acoustic stimulation (AcouStim), and 3. Tinnitus (Tin). Enrichment analysis by the DAVID database resulted in similar Gene Ontology (GO) terms for cellular components in all gene lists, reflecting synaptic structures known to be involved in auditory processing. The STRING protein-protein interaction (PPI) network and the Cytoscape data analyzer were used to identify the top two high-degree proteins (HDPs) and their high-score interaction proteins (HSIPs) identified by the combined score (CS) of the corresponding edges. The top two protein pairs (key proteins) for the PoS are BDNF-GDNF and OTOF-CACNA1D and for the AcouStim process BDNF-NTRK2 and TH-CALB1. The Tin process showed BDNF and NGF as HDPs, with high-score interactions with NTRK1 and NGFR at a comparable level. Compared to the PoS and AcouStim process, the number of HSIPs of key proteins (CS > 90. percentile) increases strongly in Tin. In the PoS and AcouStim networks, BDNF receptor signaling is the dominant pathway, and in the Tin network, the NGF-signaling pathway is of similar importance. Key proteins and their HSIPs are good indicators of biological processes and of signaling pathways characteristic for the normal hearing on the one hand and tinnitus on the other.
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Affiliation(s)
- Johann Gross
- Tinnitus Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.
- Leibniz Society of Science Berlin, Berlin, Germany.
| | - Marlies Knipper
- Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Center (THRC), Molecular Physiology of Hearing, University of Tübingen, Tübingen, Germany
- Leibniz Society of Science Berlin, Berlin, Germany
| | - Birgit Mazurek
- Tinnitus Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Role of Delta/Notch-like epidermal growth factor-related receptor in gastric cancer patients and cells and its clinical significance. Anticancer Drugs 2022; 33:1175-1181. [PMID: 36255071 PMCID: PMC9575567 DOI: 10.1097/cad.0000000000001379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Gastric cancer (GC) is a common digestive system malignancy. The aim of this study was to explore the role of Delta/Notch-like epidermal growth factor-related receptor (DNER) in GC patients and cells. Gene expression omnibus data base public databases were used to analyze the DNER expression in GC patient. A total of 30 cases of GC and adjacent tissue samples were retrospectively obtained to analyze the DNER expression. MTT assay was conducted to measure the cell viability. The apoptosis rate of GC cells was determined by flow cytometry. The migration and invasion were detected by transwell assay. Real-time polymerase chain reaction and western blot were performed to measure the DNER expression. Bioinformatics tools exhibited that DNER expression is significantly upregulated in the GC, which was also found in GC tissues and cells. The high levels of DNER were closely related the tumor size, sex and lymph node metastasis. Additionally, the survival rate of patients with high DNER expression is decreased. Furthermore, knockdown of DNER inhibits the proliferation, migration and invasion, and induces the apoptosis rate of the GC cells. DNER was upregulated in GC and knockdown of DNER inhibits the growth and metastasis of DNER. DNER may be a potential prognostic biomarker and therapeutic target of GC patients.
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4
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Yigider AP, Yigit O. Biomarkers in Otorhinolaryngology. Biomark Med 2022. [DOI: 10.2174/9789815040463122010013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Biomarkers of otorhinolaryngologic diseases with higher insult over a
person’s him/herself and overall health services are summarized in brief. In order to
define, diagnose, treat and monitor any disease markers are needed.
Otorhinolaryngology (ORL) is interested in special disease entities of the region
besides otorhinolaryngologic involvements of the systemic diseases and unique forms
of pathologies such as cholesteatoma, Meniere’s disease and otosclerosis. Neoplasia is
another heading to deal with. In the following chapter, one will find an overview of
molecules that have been used as a biomarker as well as the end points of the present
research on the issue relevant with ORL. Day by day, new molecules are being named
however, the pathways of action are rather the same. Readers will find the headings
related to the most common diseases of the field, informing them about where to look
for defining new strategies of understanding of each disease.
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Affiliation(s)
- Ayse Pelin Yigider
- Istanbul Research and Training Hospital Otorhinolaryngology,Istanbul Research and Training Hospital Otorhinolaryngology, Istanbul,Turkey
| | - Ozgur Yigit
- Istanbul Research and Training Hospital Otorhinolaryngology, Istanbul, Turkey
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5
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Wang Z, Li Z, Wu Q, Li C, Li J, Zhang Y, Wang C, Sun S, Sun S. DNER promotes epithelial-mesenchymal transition and prevents chemosensitivity through the Wnt/β-catenin pathway in breast cancer. Cell Death Dis 2020; 11:642. [PMID: 32811806 PMCID: PMC7434780 DOI: 10.1038/s41419-020-02903-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 08/02/2020] [Accepted: 08/03/2020] [Indexed: 12/24/2022]
Abstract
Breast cancer (BC) is the most common malignant tumour in women worldwide, and one of the most common fatal tumours in women. Delta/Notch-like epidermal growth factor (EGF)-related receptor (DNER) is a transmembrane protein involved in the development of tumours. The role and potential mechanism of DNER in epithelial-mesenchymal transition (EMT) and apoptosis in BC are not fully understood. We find that DNER is overexpressed in BC tissue, especially triple-negative breast cancer (TNBC) tissue, and related to the survival of BC and TNBC patients. In addition, DNER regulates cell EMT to enhance the proliferation and metastasis of BC cells via the Wnt/β-catenin pathway in vitro and in vivo. Moreover, the expression levels of β-catenin and DNER in BD tissue are positively correlated. The simultaneously high expression of DNER and β-catenin contributes to poor prognosis in BC patients. Finally, DNER protects BC cells from epirubicin-induced growth inhibition and apoptosis via the Wnt/β-catenin pathway. In conclusion, these results suggest that DNER induces EMT and prevents apoptosis by the Wnt/β-catenin pathway, ultimately promoting the malignant progression of BC. In conclusion, our study demonstrates that DNER functions as an oncogene and potentially valuable therapeutic target for BC.
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Affiliation(s)
- Zhong Wang
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Zhiyu Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Qi Wu
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Chenyuan Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Juanjuan Li
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yimin Zhang
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Changhua Wang
- Department of Pathophysiology, Wuhan University School of Basic Medical Sciences, Wuhan, Hubei, China
| | - Si Sun
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
| | - Shengrong Sun
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, China.
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Lin HC, Ren Y, Lysaght AC, Kao SY, Stankovic KM. Proteome of normal human perilymph and perilymph from people with disabling vertigo. PLoS One 2019; 14:e0218292. [PMID: 31185063 PMCID: PMC6559673 DOI: 10.1371/journal.pone.0218292] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/29/2019] [Indexed: 12/20/2022] Open
Abstract
The vast majority of hearing loss, the most common sensory impairment, and vertigo, which commonly causes falls, both reflect underlying dysfunction of inner ear cells. Perilymph sampling can thus provide molecular cues to hearing and balance disorders. While such "liquid biopsy" of the inner ear is not yet in routine clinical practice, previous studies have uncovered alterations in perilymph in patients with certain types of hearing loss. However, the proteome of perilymph from patients with intact hearing has been unknown. Furthermore, no complete characterization of perilymph from patients with vestibular dysfunction has been reported. Here, using liquid-chromatography with tandem mass spectrometry, we analyzed samples of normal perilymph collected from three patients with skull base meningiomas and intact hearing. We identified 228 proteins that were common across the samples, establishing a greatly expanded proteome of the previously inferred normal human perilymph. Further comparison to perilymph obtained from three patients with vestibular dysfunction with drop attacks due to Meniere's disease showed 38 proteins with significantly differential abundance. The abundance of four protein candidates with previously unknown roles in inner ear biology was validated in murine cochleae by immunohistochemistry and in situ hybridization: AACT, HGFAC, EFEMP1, and TGFBI. Together, these results motivate future work in characterizing the normal human perilymph and identifying biomarkers of inner ear disease.
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Affiliation(s)
- Hsiao-Chun Lin
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eaton Peabody Laboratories and Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, United States of America
| | - Yin Ren
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eaton Peabody Laboratories and Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, United States of America
| | - Andrew C. Lysaght
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eaton Peabody Laboratories and Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, United States of America
- Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, United States of America
| | - Shyan-Yuan Kao
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eaton Peabody Laboratories and Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, United States of America
| | - Konstantina M. Stankovic
- Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts, United States of America
- Eaton Peabody Laboratories and Department of Otolaryngology, Massachusetts Eye and Ear, Boston, Massachusetts, United States of America
- Program in Speech and Hearing Bioscience and Technology, Harvard Medical School, Boston, United States of America
- Harvard Program in Therapeutic Science, Harvard University, Boston, United States of America
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7
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Du J, Wang X, Zhang X, Zhang X, Jiang H. DNER modulates the length, polarity and synaptogenesis of spiral ganglion neurons via the Notch signaling pathway. Mol Med Rep 2017; 17:2357-2365. [PMID: 29207144 PMCID: PMC5783477 DOI: 10.3892/mmr.2017.8115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 02/16/2017] [Indexed: 02/05/2023] Open
Abstract
The Delta/Notch-like epidermal growth factor-related receptor (DNER) serves an important role in the developing central nervous system. However, the actions of DNER in the development of the spiral ganglion in the inner ear have yet to be elucidated. Wild-type C57BL/6 mice were housed and time-mated for use in the present study. Primary neuronal cultures were prepared using spiral ganglion progenitors isolated from the modiolus of postnatal day 1 (P1) mice. DNER recombinant lentiviral vectors were constructed and transfected into the cultured primary neurons. The relative proportion of differentiated neurons and the length of their neurites were evaluated using microscopy. The results of the present study demonstrated that DNER was expressed in spiral ganglion neurons (SGNs) that exhibited significant polarity in the early differentiation stages; DNER expression gradually decreased until the polarity was lost on week 35. The in vitro expression of DNER was revealed to be similar to that in vivo. When DNER expression was silenced using RNA interference, the polarity of the differentiated neurons was altered and they exhibited significantly reduced dendritic length. In addition, the proportion of bipolar neurons was decreased compared with the control group. Furthermore, the expression of α-synuclein and the GluR2/3 subunits of the α-amin-o-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptor were also reduced in cultured neurons in which DNER was silenced. Notch1 was co-expressed with DNER in SGNs isolated from P1 mice. The indirect Notch inhibitor N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester also affected the polarity and the formation of protrusions, and reduced the expression of DNER and glial fibrillary acidic protein in SGNs. In conclusion, the present study demonstrated that DNER was expressed in SGNs and appeared to be involved in the mechanisms underlying neuronal polarity and neuritogenesis, via a Notch-dependent signaling pathway.
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Affiliation(s)
- Jintao Du
- Department of Otorhinolaryngology Head & Neck Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Xianren Wang
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xiaobo Zhang
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xuemei Zhang
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Hongyan Jiang
- Department of Otorhinolaryngology, The First Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510080, P.R. China
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8
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Warchol ME, Stone J, Barton M, Ku J, Veile R, Daudet N, Lovett M. ADAM10 and γ-secretase regulate sensory regeneration in the avian vestibular organs. Dev Biol 2017; 428:39-51. [PMID: 28526588 PMCID: PMC5873298 DOI: 10.1016/j.ydbio.2017.05.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/15/2017] [Accepted: 05/15/2017] [Indexed: 11/19/2022]
Abstract
The loss of sensory hair cells from the inner ear is a leading cause of hearing and balance disorders. The mammalian ear has a very limited ability to replace lost hair cells, but the inner ears of non-mammalian vertebrates can spontaneously regenerate hair cells after injury. Prior studies have shown that replacement hair cells are derived from epithelial supporting cells and that the differentiation of new hair cells is regulated by the Notch signaling pathway. The present study examined molecular influences on regeneration in the avian utricle, which has a particularly robust regenerative ability. Chicken utricles were placed in organotypic culture and hair cells were lesioned by application of the ototoxic antibiotic streptomycin. Cultures were then allowed to regenerate in vitro for seven days. Some specimens were treated with small molecule inhibitors of γ-secretase or ADAM10, proteases which are essential for transmission of Notch signaling. As expected, treatment with both inhibitors led to increased numbers of replacement hair cells. However, we also found that inhibition of both proteases resulted in increased regenerative proliferation. Subsequent experiments showed that inhibition of γ-secretase or ADAM10 could also trigger proliferation in undamaged utricles. To better understand these phenomena, we used RNA-Seq profiling to characterize changes in gene expression following γ-secretase inhibition. We observed expression patterns that were consistent with Notch pathway inhibition, but we also found that the utricular sensory epithelium contains numerous γ-secretase substrates that might regulate cell cycle entry and possibly supporting cell-to-hair cell conversion. Together, our data suggest multiple roles for γ-secretase and ADAM10 in vestibular hair cell regeneration.
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Affiliation(s)
- Mark E Warchol
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Jennifer Stone
- The Virginia Merrill Bloedel Hearing Research Center and Department of Otolaryngology-Head and Neck Surgery, University of Washington School of Medicine, Seattle, WA 98195, United States
| | - Matthew Barton
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Jeffrey Ku
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Rose Veile
- Department of Otolaryngology, Washington University School of Medicine, St. Louis, MO 63110, United States; Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Nicolas Daudet
- Center for Auditory Research, University College London, London, United Kingdom
| | - Michael Lovett
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, United States; NHLI, Imperial College, London, United Kingdom
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Induction of differentiation of human embryonic stem cells into functional hair-cell-like cells in the absence of stromal cells. Int J Biochem Cell Biol 2015; 81:208-222. [PMID: 26615761 DOI: 10.1016/j.biocel.2015.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/27/2015] [Accepted: 11/20/2015] [Indexed: 02/07/2023]
Abstract
Sensorineural hearing loss and vestibular dysfunction have become the most common forms of sensory defects. Stem cell-based therapeutic strategies for curing hearing loss are being developed. Several attempts to develop hair cells by using chicken utricle stromal cells as feeder cells have resulted in phenotypic conversion of stem cells into inner ear hair-cell-like cells. Here, we induced the differentiation of human embryonic stem cells (hESCs) into otic epithelial progenitors (OEPs), and further induced the differentiation of OEPs into hair-cell-like cells using different substrates. Our results showed that OEPs cultured on the chicken utricle stromal cells with the induction medium could differentiate into hair-cell-like cells with stereociliary bundles. Co-culture with stromal cells, however, may be problematic for subsequent examination of the induced hair-cell-like cells. In order to avoid the interference from stromal cells, we cultured OEPs on laminin with different induction media and examined the effects of the induction medium on the differentiation potentials of OEPs into hair-cell-like cells. The results revealed that the culture of OEPs on laminin with the conditioned medium from chicken utricle stromal cells supplemented with EGF and all-trans retinoic acid (RA) could promote the organization of cells into epithelial clusters displaying hair-cell-like cells with stereociliary bundles. These cells also displayed the expected electrophysiological properties.
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Zeng C, Xing R, Liu J, Xing F. Role of CSL-dependent and independent Notch signaling pathways in cell apoptosis. Apoptosis 2015; 21:1-12. [DOI: 10.1007/s10495-015-1188-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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11
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Korrapati S, Roux I, Glowatzki E, Doetzlhofer A. Notch signaling limits supporting cell plasticity in the hair cell-damaged early postnatal murine cochlea. PLoS One 2013; 8:e73276. [PMID: 24023676 PMCID: PMC3758270 DOI: 10.1371/journal.pone.0073276] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/18/2013] [Indexed: 12/02/2022] Open
Abstract
In mammals, auditory hair cells are generated only during embryonic development and loss or damage to hair cells is permanent. However, in non-mammalian vertebrate species, such as birds, neighboring glia-like supporting cells regenerate auditory hair cells by both mitotic and non-mitotic mechanisms. Based on work in intact cochlear tissue, it is thought that Notch signaling might restrict supporting cell plasticity in the mammalian cochlea. However, it is unresolved how Notch signaling functions in the hair cell-damaged cochlea and the molecular and cellular changes induced in supporting cells in response to hair cell trauma are poorly understood. Here we show that gentamicin-induced hair cell loss in early postnatal mouse cochlear tissue induces rapid morphological changes in supporting cells, which facilitate the sealing of gaps left by dying hair cells. Moreover, we provide evidence that Notch signaling is active in the hair cell damaged cochlea and identify Hes1, Hey1, Hey2, HeyL, and Sox2 as targets and potential Notch effectors of this hair cell-independent mechanism of Notch signaling. Using Cre/loxP based labeling system we demonstrate that inhibition of Notch signaling with a γ- secretase inhibitor (GSI) results in the trans-differentiation of supporting cells into hair cell-like cells. Moreover, we show that these hair cell-like cells, generated by supporting cells have molecular, cellular, and basic electrophysiological properties similar to immature hair cells rather than supporting cells. Lastly, we show that the vast majority of these newly generated hair cell-like cells express the outer hair cell specific motor protein prestin.
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Affiliation(s)
- Soumya Korrapati
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Hearing and Balance, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Isabelle Roux
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Hearing and Balance, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Elisabeth Glowatzki
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Hearing and Balance, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Angelika Doetzlhofer
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Sensory Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- Center for Hearing and Balance, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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12
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Hsieh FY, Ma TL, Shih HY, Lin SJ, Huang CW, Wang HY, Cheng YC. Dner inhibits neural progenitor proliferation and induces neuronal and glial differentiation in zebrafish. Dev Biol 2013; 375:1-12. [PMID: 23328254 DOI: 10.1016/j.ydbio.2013.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 12/17/2012] [Accepted: 01/02/2013] [Indexed: 11/19/2022]
Abstract
Delta/notch-like epidermal growth factor (EGF)-related receptor (DNER) is a single-pass transmembrane protein found to be a novel ligand in the Notch signaling pathway. Its function was previously characterized in the developing cerebellum and inner ear hair cells. In this study, we isolated a zebrafish homolog of DNER and showed that this gene is expressed in the developing nervous system. Overexpression of dner or the intracellular domain of dner was sufficient to inhibit the proliferation of neural progenitors and induce neuronal and glial differentiation. In contrast, the knockdown of endogenous Dner expression using antisense morpholino oligonucleotides increased the proliferation of neural progenitors and maintained neural cells in a progenitor status through inhibition of neuronal and glial differentiation. Through analysis of the antagonistic effect on the Delta ligand and the role of the potential downstream mediator Deltex1, we showed that Dner acts in Notch-dependent and Notch-independent manner. This is the first study to demonstrate a role for Dner in neural progenitors and neuronal differentiation and provides new insights into mediation of neuronal development and differentiation by the Notch signaling pathway.
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Affiliation(s)
- Fu-Yu Hsieh
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, Taoyuan 333, Taiwan
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13
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Kowalik L, Hudspeth AJ. A search for factors specifying tonotopy implicates DNER in hair-cell development in the chick's cochlea. Dev Biol 2011; 354:221-31. [PMID: 21497156 DOI: 10.1016/j.ydbio.2011.03.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 03/29/2011] [Accepted: 03/31/2011] [Indexed: 11/16/2022]
Abstract
The accurate perception of sound frequency by vertebrates relies upon the tuning of hair cells, which are arranged along auditory organs according to frequency. This arrangement, which is termed a tonotopic gradient, results from the coordination of many cellular and extracellular features. Seeking the mechanisms that orchestrate those features and govern the tonotopic gradient, we used expression microarrays to identify genes differentially expressed between the high- and low-frequency cochlear regions of the chick (Gallus gallus). Of the three signaling systems that were represented extensively in the results, we focused on the notch pathway and particularly on DNER, a putative notch ligand, and PTPζ, a receptor phosphatase that controls DNER trafficking. Immunohistochemistry confirmed that both proteins are expressed more strongly in hair cells at the cochlear apex than in those at the base. At the apical surface of each hair cell, the proteins display polarized, mutually exclusive localization patterns. Using morpholinos to decrease the expression of DNER or PTPζ as well as a retroviral vector to overexpress DNER, we observed disturbances of hair-bundle morphology and orientation. Our results suggest a role for DNER and PTPζ in hair-cell development and possibly in the specification of tonotopy.
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Affiliation(s)
- Lukasz Kowalik
- Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, Campus Box 314, The Rockefeller University, 1230 York Avenue, New York, NY 10065-6399, USA
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