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Washausen S, Knabe W. Chicken embryos share mammalian patterns of apoptosis in the posterior placodal area. J Anat 2019; 234:551-563. [PMID: 30734277 DOI: 10.1111/joa.12945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2019] [Indexed: 01/04/2023] Open
Abstract
In the posterior placodal area (PPA) of C57BL/6N mice and primate-related Tupaia belangeri (Scandentia), apoptosis helps to establish morphologically separated otic and epibranchial placodes. Here, we demonstrate that basically identical patterns of apoptosis pass rostrocaudally through the Pax2+ PPA of chicken embryos. Interplacodal apoptosis eliminates unneeded cells either between the otic anlage and the epibranchial placodes 1, 2 and/or 3, respectively (type A), or between neighbouring epibranchial placodes (type B). These observations support the idea that in chicken embryos, as in mammals, interplacodal apoptosis serves to remove vestigial lateral line placodes (Washausen & Knabe, 2018, Biol Open 7, bio031815). A special case represents the recently discovered Pax2- /Sox2+ paratympanic organ (PTO) placode that has been postulated to be molecularly distinct from and developmentally independent of the ventrally adjacent first epibranchial (or 'geniculate') placode (O'Neill et al. 2012, Nat Commun 3, 1041). We show that Sox2+ (PTO placodal) cells seem to segregate from the Pax2+ geniculate placode, and that absence of Pax2 in the mature PTO placode is due to secondary loss. We further report that, between Hamburger-Hamilton (HH) stages HH14 and HH26, apoptosis in the combined anlage of the first epibranchial and PTO placodes is almost exclusively found within and/or immediately adjacent to the dorsally located PTO placode. Hence, apoptosis appears to support decision-making processes among precursor cells of the early developing PTO placode and, later, regression of the epibranchial placodes 2 and 3.
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Affiliation(s)
- Stefan Washausen
- Department Prosektur Anatomie, Westfälische Wilhelms-University, Münster, Germany
| | - Wolfgang Knabe
- Department Prosektur Anatomie, Westfälische Wilhelms-University, Münster, Germany
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2
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Samarajeewa A, Lenz DR, Xie L, Chiang H, Kirchner R, Mulvaney JF, Edge ASB, Dabdoub A. Transcriptional response to Wnt activation regulates the regenerative capacity of the mammalian cochlea. Development 2018; 145:dev.166579. [PMID: 30389848 PMCID: PMC6288390 DOI: 10.1242/dev.166579] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/25/2018] [Indexed: 01/04/2023]
Abstract
Lack of sensory hair cell (HC) regeneration in mammalian adults is a major contributor to hearing loss. In contrast, the neonatal mouse cochlea retains a transient capacity for regeneration, and forced Wnt activation in neonatal stages promotes supporting cell (SC) proliferation and induction of ectopic HCs. We currently know little about the temporal pattern and underlying mechanism of this age-dependent regenerative response. Using an in vitro model, we show that Wnt activation promotes SC proliferation following birth, but prior to postnatal day (P) 5. This age-dependent decline in proliferation occurs despite evidence that the Wnt pathway is postnatally active and can be further enhanced by Wnt stimulators. Using an in vivo mouse model and RNA sequencing, we show that proliferation in the early neonatal cochlea is correlated with a unique transcriptional response that diminishes with age. Furthermore, we find that augmenting Wnt signaling through the neonatal stages extends the window for HC induction in response to Notch signaling inhibition. Our results suggest that the downstream transcriptional response to Wnt activation, in part, underlies the regenerative capacity of the mammalian cochlea. Summary: Canonical Wnt activation in the mammalian cochlea elicits a unique, age-dependent transcriptional response, which in part regulates the regenerative capacity of supporting cells during cochlear maturation.
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Affiliation(s)
- Anshula Samarajeewa
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, M5S 1A8, Canada
| | - Danielle R Lenz
- Department of Otolaryngology, Harvard Medical School, Boston, MA 02114, USA.,Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - Lihong Xie
- Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto ON, M4N 3M5, Canada.,Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, Nanning Guangxi, 530021, China
| | - Hao Chiang
- Department of Otolaryngology, Harvard Medical School, Boston, MA 02114, USA.,Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - Rory Kirchner
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Joanna F Mulvaney
- Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto ON, M4N 3M5, Canada
| | - Albert S B Edge
- Department of Otolaryngology, Harvard Medical School, Boston, MA 02114, USA.,Eaton-Peabody Laboratory, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - Alain Dabdoub
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto ON, M5S 1A8, Canada .,Biological Sciences, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto ON, M4N 3M5, Canada.,Department of Otolaryngology - Head & Neck Surgery, University of Toronto, Toronto ON, M5G 2C4, Canada
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3
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Mulvaney JF, Thompkins C, Noda T, Nishimura K, Sun WW, Lin SY, Coffin A, Dabdoub A. Kremen1 regulates mechanosensory hair cell development in the mammalian cochlea and the zebrafish lateral line. Sci Rep 2016; 6:31668. [PMID: 27550540 PMCID: PMC4994024 DOI: 10.1038/srep31668] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/21/2016] [Indexed: 02/06/2023] Open
Abstract
Here we present spatio-temporal localization of Kremen1, a transmembrane receptor, in the mammalian cochlea, and investigate its role in the formation of sensory organs in mammal and fish model organisms. We show that Kremen1 is expressed in prosensory cells during cochlear development and in supporting cells of the adult mouse cochlea. Based on this expression pattern, we investigated whether Kremen1 functions to modulate cell fate decisions in the prosensory domain of the developing cochlea. We used gain and loss-of-function experiments to show that Kremen1 is sufficient to bias cells towards supporting cell fate, and is implicated in suppression of hair cell formation. In addition to our findings in the mouse cochlea, we examined the effects of over expression and loss of Kremen1 in the zebrafish lateral line. In agreement with our mouse data, we show that over expression of Kremen1 has a negative effect on the number of mechanosensory cells that form in the zebrafish neuromasts, and that fish lacking Kremen1 protein develop more hair cells per neuromast compared to wild type fish. Collectively, these data support an inhibitory role for Kremen1 in hair cell fate specification.
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Affiliation(s)
- Joanna F Mulvaney
- Biological Sciences, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada
| | - Cathrine Thompkins
- College of Arts and Sciences and Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA, USA
| | - Teppei Noda
- Biological Sciences, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada
| | - Koji Nishimura
- Biological Sciences, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada
| | - Willy W Sun
- Biological Sciences, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada
| | - Shuh-Yow Lin
- Department of Surgery, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Allison Coffin
- College of Arts and Sciences and Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA, USA
| | - Alain Dabdoub
- Biological Sciences, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON, M4N 3M5, Canada.,Department of Otolaryngology - Head and Neck Surgery, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
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4
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Żak M, van Oort T, Hendriksen FG, Garcia MI, Vassart G, Grolman W. LGR4 and LGR5 Regulate Hair Cell Differentiation in the Sensory Epithelium of the Developing Mouse Cochlea. Front Cell Neurosci 2016; 10:186. [PMID: 27559308 PMCID: PMC4988241 DOI: 10.3389/fncel.2016.00186] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/19/2016] [Indexed: 02/06/2023] Open
Abstract
In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the activity of Wnt/β-catenin signaling is modulated by an interaction between LGR receptors and their ligands from the R-spondin family. The deficiency in Lgr4 and Lgr5 genes leads to developmental malformations and lethality. Using the Lgr5 knock-in mouse line we show that loss of LGR5 function increases Wnt/β-catenin activity in the embryonic cochlea, resulting in a mild overproduction of inner and outer hair cells (OHC). Supernumerary hair cells are likely formed due to an up-regulation of the “pro-hair cell” transcription factors Atoh1, Nhlh1, and Pou4f3. Using a hypomorphic Lgr4 mouse model we showed a mild overproduction of OHCs in the heterozygous and homozygous Lgr4 mice. The loss of LGR4 function prolonged the proliferation in the mid-basal turn of E13 cochleae, causing an increase in the number of SOX2-positive precursor cells within the pro-sensory domain. The premature differentiation of hair cells progressed in a medial to lateral gradient in Lgr4 deficient embryos. No significant up-regulation of Atoh1 was observed following Lgr4 deletion. Altogether, our findings suggest that LGR4 and LGR5 play an important role in the regulation of hair cell differentiation in the embryonic cochlea.
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Affiliation(s)
- Magdalena Żak
- Department of Otorhinolaryngology and Head and Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
| | - Thijs van Oort
- Department of Otorhinolaryngology and Head and Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
| | - Ferry G Hendriksen
- Department of Otorhinolaryngology and Head and Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
| | - Marie-Isabelle Garcia
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Faculty of Medicine, Université Libre de Bruxelles Brussels, Belgium
| | - Gilbert Vassart
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Faculty of Medicine, Université Libre de Bruxelles Brussels, Belgium
| | - Wilko Grolman
- Department of Otorhinolaryngology and Head and Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
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5
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Żak M, Klis SFL, Grolman W. The Wnt and Notch signalling pathways in the developing cochlea: Formation of hair cells and induction of regenerative potential. Int J Dev Neurosci 2015; 47:247-58. [PMID: 26471908 DOI: 10.1016/j.ijdevneu.2015.09.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 09/25/2015] [Accepted: 09/26/2015] [Indexed: 12/21/2022] Open
Abstract
The Wnt and Notch signalling pathways control proliferation, specification, and cell fate choices during embryonic development and in adult life. Hence, there is much interest in both signalling pathways in the context of stem cell biology and tissue regeneration. In the developing ear, the Wnt and Notch signalling pathways specify otic cells and refine the ventral boundary of the otic placode. Since both signalling pathways control events essential for the formation of sensory cells, such as proliferation and hair cell differentiation, these pathways could hold promise for the regeneration of hair cells in adult mammalian cochlea. Indeed, modulating either the Wnt or Notch pathways can trigger the regenerative potential of supporting cells. In the neonatal mouse cochlea, Notch-mediated regeneration of hair cells partially depends on Wnt signalling, which implies an interaction between the pathways. This review presents how the Wnt and Notch signalling pathways regulate the formation of sensory hair cells and how modulating their activity induces regenerative potential in the mammalian cochlea.
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Affiliation(s)
- Magdalena Żak
- Department of Otorhinolaryngology and Head & Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
| | - Sjaak F L Klis
- Department of Otorhinolaryngology and Head & Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Wilko Grolman
- Department of Otorhinolaryngology and Head & Neck Surgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
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Mellott AJ, Devarajan K, Shinogle HE, Moore DS, Talata Z, Laurence JS, Forrest ML, Noji S, Tanaka E, Staecker H, Detamore MS. Nonviral Reprogramming of Human Wharton's Jelly Cells Reveals Differences Between ATOH1 Homologues. Tissue Eng Part A 2015; 21:1795-809. [PMID: 25760435 DOI: 10.1089/ten.tea.2014.0340] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The transcription factor atonal homolog 1 (ATOH1) has multiple homologues that are functionally conserved across species and is responsible for the generation of sensory hair cells. To evaluate potential functional differences between homologues, human and mouse ATOH1 (HATH1 and MATH-1, respectively) were nonvirally delivered to human Wharton's jelly cells (hWJCs) for the first time. Delivery of HATH1 to hWJCs demonstrated superior expression of inner ear hair cell markers and characteristics than delivery of MATH-1. Inhibition of HES1 and HES5 signaling further increased the atonal effect. Transfection of hWJCs with HATH1 DNA, HES1 siRNA, and HES5 siRNA displayed positive identification of key hair cell and support cell markers found in the cochlea, as well as a variety of cell shapes, sizes, and features not native to hair cells, suggesting the need for further examination of other cell types induced by HATH1 expression. In the first side-by-side evaluation of HATH1 and MATH-1 in human cells, substantial differences were observed, suggesting that the two atonal homologues may not be interchangeable in human cells, and artificial expression of HATH1 in hWJCs requires further study. In the future, this line of research may lead to engineered systems that would allow for evaluation of drug ototoxicity or potentially even direct therapeutic use.
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Affiliation(s)
- Adam J Mellott
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas
| | | | - Heather E Shinogle
- 3Microscopy and Analytical Imaging Lab, University of Kansas, Lawrence, Kansas
| | - David S Moore
- 3Microscopy and Analytical Imaging Lab, University of Kansas, Lawrence, Kansas
| | - Zsolt Talata
- 4Department of Mathematics, University of Kansas, Lawrence, Kansas
| | - Jennifer S Laurence
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,5Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas
| | - M Laird Forrest
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,5Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas
| | - Sumihare Noji
- 6Department of Life Systems, Institute of Technology and Science, The University of Tokushima, Minami-Jyosanjima-cho, Tokushima, Japan
| | - Eiji Tanaka
- 7Department of Orthodontics and Dentofacial Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School, Kuramoto-cho, Tokushima, Japan
| | - Hinrich Staecker
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,8Department of Otolaryngology, Head and Neck Surgery, University of Kansas Medical Center, Kansas City, Kansas
| | - Michael S Detamore
- 1Bioengineering Graduate Program, University of Kansas, Lawrence, Kansas.,9Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas
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