1
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Ishan M, Wang Z, Zhao P, Yao Y, Stice SL, Wells L, Mishina Y, Liu HX. Taste papilla cell differentiation requires the regulation of secretory protein production by ALK3-BMP signaling in the tongue mesenchyme. Development 2023; 150:dev201838. [PMID: 37680190 PMCID: PMC10560570 DOI: 10.1242/dev.201838] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/01/2023] [Indexed: 09/09/2023]
Abstract
Taste papillae are specialized organs, each of which comprises an epithelial wall hosting taste buds and a core of mesenchymal tissue. In the present study, we report that during early taste papilla development in mouse embryos, bone morphogenetic protein (BMP) signaling mediated by type 1 receptor ALK3 in the tongue mesenchyme is required for epithelial Wnt/β-catenin activity and taste papilla differentiation. Mesenchyme-specific knockout (cKO) of Alk3 using Wnt1-Cre and Sox10-Cre resulted in an absence of taste papillae at E12.0. Biochemical and cell differentiation analyses demonstrated that mesenchymal ALK3-BMP signaling governed the production of previously unappreciated secretory proteins, i.e. it suppressed those that inhibit and facilitated those that promote taste papilla differentiation. Bulk RNA-sequencing analysis revealed many more differentially expressed genes (DEGs) in the tongue epithelium than in the mesenchyme in Alk3 cKO versus control. Moreover, we detected downregulated epithelial Wnt/β-catenin signaling and found that taste papilla development in the Alk3 cKO was rescued by the GSK3β inhibitor LiCl, but not by Wnt3a. Our findings demonstrate for the first time the requirement of tongue mesenchyme in taste papilla cell differentiation.
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Affiliation(s)
- Mohamed Ishan
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Zhonghou Wang
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Peng Zhao
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Yao Yao
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Steven L. Stice
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
| | - Lance Wells
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Yuji Mishina
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hong-Xiang Liu
- Regenerative Bioscience Center, Department of Animal and Dairy Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA
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2
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Xu J, Iyyanar PPR, Lan Y, Jiang R. Sonic hedgehog signaling in craniofacial development. Differentiation 2023; 133:60-76. [PMID: 37481904 PMCID: PMC10529669 DOI: 10.1016/j.diff.2023.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/25/2023]
Abstract
Mutations in SHH and several other genes encoding components of the Hedgehog signaling pathway have been associated with holoprosencephaly syndromes, with craniofacial anomalies ranging in severity from cyclopia to facial cleft to midfacial and mandibular hypoplasia. Studies in animal models have revealed that SHH signaling plays crucial roles at multiple stages of craniofacial morphogenesis, from cranial neural crest cell survival to growth and patterning of the facial primordia to organogenesis of the palate, mandible, tongue, tooth, and taste bud formation and homeostasis. This article provides a summary of the major findings in studies of the roles of SHH signaling in craniofacial development, with emphasis on recent advances in the understanding of the molecular and cellular mechanisms regulating the SHH signaling pathway activity and those involving SHH signaling in the formation and patterning of craniofacial structures.
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Affiliation(s)
- Jingyue Xu
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.
| | - Paul P R Iyyanar
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Yu Lan
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA; Division of Plastic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA; Departments of Pediatrics and Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Rulang Jiang
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA; Division of Plastic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA; Departments of Pediatrics and Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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3
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Whiddon ZD, Marshall JB, Alston DC, McGee AW, Krimm RF. Rapid structural remodeling of peripheral taste neurons is independent of taste cell turnover. PLoS Biol 2023; 21:e3002271. [PMID: 37651406 PMCID: PMC10499261 DOI: 10.1371/journal.pbio.3002271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 09/13/2023] [Accepted: 07/22/2023] [Indexed: 09/02/2023] Open
Abstract
Taste bud cells are constantly replaced in taste buds as old cells die and new cells migrate into the bud. The perception of taste relies on new taste bud cells integrating with existing neural circuitry, yet how these new cells connect with a taste ganglion neuron is unknown. Do taste ganglion neurons remodel to accommodate taste bud cell renewal? If so, how much of the structure of taste axons is fixed and how much remodels? Here, we measured the motility and branching of individual taste arbors (the portion of the axon innervating taste buds) in mice over time with two-photon in vivo microscopy. Terminal branches of taste arbors continuously and rapidly remodel within the taste bud. This remodeling is faster than predicted by taste bud cell renewal, with terminal branches added and lost concurrently. Surprisingly, blocking entry of new taste bud cells with chemotherapeutic agents revealed that remodeling of the terminal branches on taste arbors does not rely on the renewal of taste bud cells. Although terminal branch remodeling was fast and intrinsically controlled, no new arbors were added to taste buds, and few were lost over 100 days. Taste ganglion neurons maintain a stable number of arbors that are each capable of high-speed remodeling. We propose that terminal branch plasticity permits arbors to locate new taste bud cells, while stability of arbor number supports constancy in the degree of connectivity and function for each neuron over time.
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Affiliation(s)
- Zachary D. Whiddon
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Jaleia B. Marshall
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - David C. Alston
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Aaron W. McGee
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Robin F. Krimm
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
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4
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Ha P, Liu TP, Li C, Zheng Z. Novel Strategies for Orofacial Soft Tissue Regeneration. Adv Wound Care (New Rochelle) 2023; 12:339-360. [PMID: 35651274 DOI: 10.1089/wound.2022.0037] [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] [Indexed: 11/12/2022] Open
Abstract
Significance: Orofacial structures are indispensable for speech and eating, and impairment disrupts whole-body health through malnutrition and poor quality of life. However, due to the unique and highly specialized cell populations, tissue architecture, and healing microenvironments, regeneration in this region is challenging and inadequately addressed to date. Recent Advances: With increasing understanding of the nuanced physiology and cellular responses of orofacial soft tissue, novel scaffolds, seeded cells, and bioactive molecules were developed in the past 5 years to specifically target orofacial soft tissue regeneration, particularly for tissues primarily found within the orofacial region such as oral mucosa, taste buds, salivary glands, and masseter muscles. Critical Issues: Due to the tightly packed and complex anatomy, orofacial soft tissue injury commonly implicates multiple tissue types, and thus functional unit reconstruction in the orofacial region is more important than single tissue regeneration. Future Directions: This article reviews the up-to-date knowledge in this highly translational topic, which provides insights into novel biologically inspired and engineered strategies for regenerating orofacial component tissues and functional units.
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Affiliation(s)
- Pin Ha
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Timothy P Liu
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Chenshuang Li
- Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Zhong Zheng
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
- School of Dentistry, University of California, Los Angeles, Los Angeles, California, USA
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5
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Mercurio S. SOX2-Sensing: Insights into the Role of SOX2 in the Generation of Sensory Cell Types in Vertebrates. Int J Mol Sci 2023; 24:ijms24087637. [PMID: 37108798 PMCID: PMC10141063 DOI: 10.3390/ijms24087637] [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: 03/28/2023] [Revised: 04/17/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
The SOX2 transcription factor is a key regulator of nervous system development, and its mutation in humans leads to a rare disease characterized by severe eye defects, cognitive defects, hearing defects, abnormalities of the CNS and motor control problems. SOX2 has an essential role in neural stem cell maintenance in specific regions of the brain, and it is one of the master genes required for the generation of induced pluripotent stem cells. Sox2 is expressed in sensory organs, and this review will illustrate how it regulates the differentiation of sensory cell types required for hearing, touching, tasting and smelling in vertebrates and, in particular, in mice.
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Affiliation(s)
- Sara Mercurio
- Department of Biotechnologies and Biosciences, University of Milan-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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6
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Ishan M, Wang Z, Zhao P, Yao Y, Stice S, Wells L, Mishina Y, Liu HX. Taste papilla cell differentiation requires tongue mesenchyme via ALK3-BMP signaling to regulate the production of secretory proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535414. [PMID: 37066397 PMCID: PMC10103976 DOI: 10.1101/2023.04.03.535414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Taste papillae are specialized organs each of which is comprised of an epithelial wall hosting taste buds and a core of mesenchymal tissue. In the present study, we report that during the early stages of embryonic development, bone morphogenetic protein (BMP) signaling mediated by type 1 receptor ALK3 in the tongue mesenchyme is required for the epithelial Wnt/β-catenin activity and taste papilla cell differentiation. Mesenchyme-specific knockout ( cKO ) of Alk3 using Wnt1-Cre and Sox10-Cre resulted in an absence of taste papillae at E12.0. Biochemical and cell differentiation analyses demonstrated that mesenchymal ALK3-BMP signaling governs the production of previously unappreciated secretory proteins, i.e., suppresses those that inhibiting and facilitates those promoting taste cell differentiation. Bulk RNA-Sequencing analysis revealed many more differentially expressed genes (DEGs) in the tongue epithelium than in the mesenchyme in Alk3 cKO vs control. Moreover, we detected a down-regulated epithelial Wnt/β-catenin signaling, and taste papilla development in the Alk3 cKO was rescued by GSK3β inhibitor LiCl, but not Wnt3a. Our findings demonstrate for the first time the requirement of tongue mesenchyme in taste papilla cell differentiation. Summary statement This is the first set of data to implicate the requirement of tongue mesenchyme in taste papilla cell differentiation.
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7
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Vercauteren Drubbel A, Beck B. Single-cell transcriptomics uncovers the differentiation of a subset of murine esophageal progenitors into taste buds in vivo. SCIENCE ADVANCES 2023; 9:eadd9135. [PMID: 36888721 PMCID: PMC9995038 DOI: 10.1126/sciadv.add9135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Mouse esophagus is lined with a stratified epithelium, which is maintained by the constant renewal of unipotent progenitors. In this study, we profiled mouse esophagus by single-cell RNA sequencing and found taste buds specifically in the cervical segment of the esophagus. These taste buds have the same cellular composition as the ones from the tongue but express fewer taste receptor types. State-of-the-art transcriptional regulatory network analysis allowed the identification of specific transcription factors associated to the differentiation of immature progenitors into the three different taste bud cell types. Lineage tracing experiments revealed that esophageal taste buds arise from squamous bipotent progenitor, thus demonstrating that all esophageal progenitors are not unipotent. Our cell resolution characterization of cervical esophagus epithelium will enable a better understanding of esophageal progenitor potency and insights into the mechanisms involved in the development of taste buds.
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Affiliation(s)
| | - Benjamin Beck
- IRIBHM, ULB/ Faculty of medicine, 808 Route de Lennik, 1070 Brussels, Belgium
- Welbio/FNRS Principal investigator at IRIBHM, 808 Route de Lennik, 1070 Brussels, Belgium
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8
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Shechtman LA, Scott JK, Larson ED, Isner TJ, Johnson BJ, Gaillard D, Dempsey PJ, Barlow LA. High Sox2 expression predicts taste lineage competency of lingual progenitors in vitro. Development 2023; 150:dev201375. [PMID: 36794954 PMCID: PMC10112921 DOI: 10.1242/dev.201375] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/19/2023] [Indexed: 02/17/2023]
Abstract
Taste buds on the tongue contain taste receptor cells (TRCs) that detect sweet, sour, salty, umami and bitter stimuli. Like non-taste lingual epithelium, TRCs are renewed from basal keratinocytes, many of which express the transcription factor SOX2. Genetic lineage tracing has shown that SOX2+ lingual progenitors give rise to both taste and non-taste lingual epithelium in the posterior circumvallate taste papilla (CVP) of mice. However, SOX2 is variably expressed among CVP epithelial cells, suggesting that their progenitor potential may vary. Using transcriptome analysis and organoid technology, we show that cells expressing SOX2 at higher levels are taste-competent progenitors that give rise to organoids comprising both TRCs and lingual epithelium. Conversely, organoids derived from progenitors that express SOX2 at lower levels are composed entirely of non-taste cells. Hedgehog and WNT/β-catenin are required for taste homeostasis in adult mice. However, manipulation of hedgehog signaling in organoids has no impact on TRC differentiation or progenitor proliferation. By contrast, WNT/β-catenin promotes TRC differentiation in vitro in organoids derived from higher but not low SOX2+ expressing progenitors.
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Affiliation(s)
- Lauren A. Shechtman
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jennifer K. Scott
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Eric D. Larson
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Otolaryngology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Trevor J. Isner
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Bryan J. Johnson
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Dany Gaillard
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Peter J. Dempsey
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Section of Developmental Biology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Linda A. Barlow
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Cell Biology, Stem Cells and Development Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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9
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Epithelial plasticity enhances regeneration of committed taste receptor cells following nerve injury. Exp Mol Med 2023; 55:171-182. [PMID: 36631663 PMCID: PMC9833027 DOI: 10.1038/s12276-022-00924-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/02/2022] [Accepted: 11/21/2022] [Indexed: 01/13/2023] Open
Abstract
Taste receptor cells are taste bud epithelial cells that are dependent upon the innervating nerve for continuous renewal and are maintained by resident tissue stem/progenitor cells. Transection of the innervating nerve causes degeneration of taste buds and taste receptor cells. However, a subset of the taste receptor cells is maintained without nerve contact after glossopharyngeal nerve transection in the circumvallate papilla in adult mice. Here, we revealed that injury caused by glossopharyngeal nerve transection triggers the remaining differentiated K8-positive taste receptor cells to dedifferentiate and acquire transient progenitor cell-like states during regeneration. Dedifferentiated taste receptor cells proliferate, express progenitor cell markers (K14, Sox2, PCNA) and form organoids in vitro. These data indicate that differentiated taste receptor cells can enter the cell cycle, acquire stemness, and participate in taste bud regeneration. We propose that dedifferentiated taste receptor cells in combination with stem/progenitor cells enhance the regeneration of taste buds following nerve injury.
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10
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Barlow LA. The sense of taste: Development, regeneration, and dysfunction. WIREs Mech Dis 2022; 14:e1547. [PMID: 34850604 PMCID: PMC11152580 DOI: 10.1002/wsbm.1547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/28/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022]
Abstract
Gustation or the sense of taste is a primary sense, which functions as a gatekeeper for substances that enter the body. Animals, including humans, ingest foods that contain appetitive taste stimuli, including those that have sweet, moderately salty and umami (glutamate) components, and tend to avoid bitter-tasting items, as many bitter compounds are toxic. Taste is mediated by clusters of heterogeneous taste receptors cells (TRCs) organized as taste buds on the tongue, and these convey taste information from the oral cavity to higher order brain centers via the gustatory sensory neurons of the seventh and ninth cranial ganglia. One remarkable aspect of taste is that taste perception is mostly uninterrupted throughout life yet TRCs within buds are constantly renewed; every 1-2 months all taste cells have been steadily replaced. In the past decades we have learned a substantial amount about the cellular and molecular regulation of taste bud cell renewal, and how taste buds are initially established during embryogenesis. Here I review more recent findings pertaining to taste development and regeneration, as well as discuss potential mechanisms underlying taste dysfunction that often occurs with disease or its treatment. This article is categorized under: Infectious Diseases > Stem Cells and Development Cancer > Stem Cells and Development Neurological Diseases > Stem Cells and Development.
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Affiliation(s)
- Linda A Barlow
- Department of Cell & Developmental Biology, Graduate Program in Cell Biology, Stem Cells & Development, and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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11
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Fine-tuning of epithelial taste bud organoid to promote functional recapitulation of taste reactivity. Cell Mol Life Sci 2022; 79:211. [PMID: 35344108 PMCID: PMC8958342 DOI: 10.1007/s00018-022-04242-0] [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: 01/20/2022] [Revised: 02/23/2022] [Accepted: 03/09/2022] [Indexed: 11/03/2022]
Abstract
Taste stem/progenitor cells from posterior mouse tongues have been used to generate taste bud organoids. However, the inaccessible location of taste receptor cells is observed in conventional organoids. In this study, we established a suspension-culture method to fine-tune taste bud organoids by apicobasal polarity alteration to form the accessible localization of taste receptor cells. Compared to conventional Matrigel-embedded organoids, suspension-cultured organoids showed comparable differentiation and renewal rates to those of taste buds in vivo and exhibited functional taste receptor cells and cycling progenitor cells. Accessible taste receptor cells enabled the direct application of calcium imaging to evaluate the taste response. Moreover, suspension-cultured organoids can be genetically altered. Suspension-cultured taste bud organoids harmoniously integrated with the recipient lingual epithelium, maintaining the taste receptor cells and gustatory innervation capacity. We propose that suspension-cultured organoids may provide an efficient model for taste research, including taste bud development, regeneration, and transplantation.
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12
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Kumari A, Li L, Ermilov AN, Franks NE, Dlugosz AA, Allen BL, Mistretta CM. Hedgehog (HH) pathway endogenous antagonist HHIP: unique lingual expression in filiform papillae during homeostasis and ectopic in fungiform papillae during HH signaling inhibition. Dev Dyn 2022; 251:1175-1195. [PMID: 35048440 DOI: 10.1002/dvdy.456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/19/2021] [Accepted: 12/19/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Hedgehog (HH) signaling is essential for homeostasis in gustatory fungiform papillae (FP) and taste buds. However, activities of HH antagonists in these tissues remain unexplored. We investigated a potential role for HH-interacting protein (HHIP), an endogenous pathway antagonist, in regulating HH signaling during taste organ homeostasis. We found a restricted pattern of Hhip-expressing cells in the anterior epithelium of each nongustatory filiform papilla (FILIF) only. To test for roles in antagonism of HH signaling, we investigated HHIP after pathway inhibition with SMO inhibition via sonidegib and Smo deletion, Gli2 deletion/suppression, or with chorda tympani/lingual nerve cut. RESULTS In all approaches, the HHIP expression pattern was retained in FILIF suggesting HH-independent regulation of HHIP. Remarkably, after pathway inhibition, HHIP expression was detected also in the conical, FILIF-like atypical FP. We found a close association of de novo expression of HHIP in atypical FP with loss of Gli1+, HH-responding cells. Further, we report that PTCH1 is another potential HH antagonist in FILIF that co-localizes with HHIP. CONCLUSIONS After HH pathway inhibition the ectopic expression of HHIP correlates with a FILIF-like morphology in atypical FP and we propose that localized expression of the HH antagonist HHIP regulates pathway inhibition to maintain FILIF during tongue homeostasis. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Archana Kumari
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America.,Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, United States of America
| | - Libo Li
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Alexandre N Ermilov
- Department of Dermatology, Michigan Medicine, Ann Arbor, Michigan, United States of America
| | - Nicole E Franks
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Andrzej A Dlugosz
- Department of Dermatology, Michigan Medicine, Ann Arbor, Michigan, United States of America.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Charlotte M Mistretta
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
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13
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Koyama S, Kondo K, Ueha R, Kashiwadani H, Heinbockel T. Possible Use of Phytochemicals for Recovery from COVID-19-Induced Anosmia and Ageusia. Int J Mol Sci 2021; 22:8912. [PMID: 34445619 PMCID: PMC8396277 DOI: 10.3390/ijms22168912] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022] Open
Abstract
The year 2020 became the year of the outbreak of coronavirus, SARS-CoV-2, which escalated into a worldwide pandemic and continued into 2021. One of the unique symptoms of the SARS-CoV-2 disease, COVID-19, is the loss of chemical senses, i.e., smell and taste. Smell training is one of the methods used in facilitating recovery of the olfactory sense, and it uses essential oils of lemon, rose, clove, and eucalyptus. These essential oils were not selected based on their chemical constituents. Although scientific studies have shown that they improve recovery, there may be better combinations for facilitating recovery. Many phytochemicals have bioactive properties with anti-inflammatory and anti-viral effects. In this review, we describe the chemical compounds with anti- inflammatory and anti-viral effects, and we list the plants that contain these chemical compounds. We expand the review from terpenes to the less volatile flavonoids in order to propose a combination of essential oils and diets that can be used to develop a new taste training method, as there has been no taste training so far. Finally, we discuss the possible use of these in clinical settings.
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Affiliation(s)
- Sachiko Koyama
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Kenji Kondo
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
| | - Rumi Ueha
- Department of Otolaryngology, Faculty of Medicine, The University of Tokyo, Tokyo 113-8655, Japan;
- Swallowing Center, The University of Tokyo Hospital, Tokyo 113-8655, Japan
| | - Hideki Kashiwadani
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan;
| | - Thomas Heinbockel
- Department of Anatomy, College of Medicine, Howard University, Washington, DC 20059, USA
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14
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Chen Z, He W, Leung TCN, Chung HY. Immortalization and Characterization of Rat Lingual Keratinocytes in a High-Calcium and Feeder-Free Culture System Using ROCK Inhibitor Y-27632. Int J Mol Sci 2021; 22:6782. [PMID: 34202585 PMCID: PMC8268148 DOI: 10.3390/ijms22136782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/17/2022] Open
Abstract
Cultured keratinocytes are desirable models for biological and medical studies. However, primary keratinocytes are difficult to maintain, and there has been little research on lingual keratinocyte culture. Here, we investigated the effect of Y-27632, a Rho kinase (ROCK) inhibitor, on the immortalization and characterization of cultured rat lingual keratinocyte (RLKs). Three Y-27632-supplemented media were screened for the cultivation of RLKs isolated from Sprague-Dawley rats. Phalloidin staining and TUNEL assay were applied to visualize cytoskeleton dynamics and cell apoptosis following Y-27632 removal. Label-free proteomics, RT-PCR, calcium imaging, and cytogenetic studies were conducted to characterize the cultured cells. Results showed that RLKs could be conditionally immortalized in a high-calcium medium in the absence of feeder cells, although they did not exhibit normal karyotypes. The removal of Y-27632 from the culture medium led to reversible cytoskeletal reorganization and nuclear enlargement without triggering apoptosis, and a total of 239 differentially expressed proteins were identified by proteomic analysis. Notably, RLKs derived from the non-taste epithelium expressed some molecular markers characteristic of taste bud cells, yet calcium imaging revealed that they rarely responded to tastants. Collectively, we established a high-calcium and feeder-free culture method for the long-term maintenance of RLKs. Our results shed some new light on the immortalization and differentiation of lingual keratinocytes.
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Affiliation(s)
- Zixing Chen
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China; (Z.C.); (T.C.N.L.)
| | - Wenmeng He
- Division of Science and Technology, Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai 519087, China;
| | - Thomas Chun Ning Leung
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China; (Z.C.); (T.C.N.L.)
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China
| | - Hau Yin Chung
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China; (Z.C.); (T.C.N.L.)
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15
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Qin Y, Sukumaran SK, Margolskee RF. Nkx2-2 expressing taste cells in endoderm-derived taste papillae are committed to the type III lineage. Dev Biol 2021; 477:232-240. [PMID: 34097879 DOI: 10.1016/j.ydbio.2021.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 05/10/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
In mammals, multiple cell-signaling pathways and transcription factors regulate development of the embryonic taste system and turnover of taste cells in the adult stage. Using single-cell RNA-Seq of mouse taste cells, we found that the homeobox-containing transcription factor Nkx2-2, a target of the Sonic Hedgehog pathway and a key regulator of the development and regeneration of multiple cell types in the body, is highly expressed in type III taste cells but not in type II or taste stem cells. Using in situ hybridization and immunostaining, we confirmed that Nkx2-2 is expressed specifically in type III taste cells in the endoderm-derived circumvallate and foliate taste papillae but not in the ectoderm-derived fungiform papillae. Lineage tracing revealed that Nkx2-2-expressing cells differentiate into type III, but not type II or type I cells in circumvallate and foliate papillae. Neonatal Nkx2-2-knockout mice did not express key type III taste cell marker genes, while the expression of type II and type I taste cell marker genes were unaffected in these mice. Our findings indicate that Nkx2-2-expressing cells are committed to the type III lineage and that Nkx2-2 may be critical for the development of type III taste cells in the posterior tongue, thus illustrating a key difference in the mechanism of type III cell lineage specification between ectoderm- and endoderm-derived taste fields.
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Affiliation(s)
- Yumei Qin
- School of Food Science and Bioengineering, Zhejiang Gongshang University, Hangzhou, PR China; Monell Chemical Senses Center, Philadelphia, PA, USA
| | - Sunil K Sukumaran
- Monell Chemical Senses Center, Philadelphia, PA, USA; Present Address: Department of Nutrition and Health Sciences, University of Nebraska- Lincoln, Lincoln, NE, USA.
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16
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Golden EJ, Larson ED, Shechtman LA, Trahan GD, Gaillard D, Fellin TJ, Scott JK, Jones KL, Barlow LA. Onset of taste bud cell renewal starts at birth and coincides with a shift in SHH function. eLife 2021; 10:64013. [PMID: 34009125 PMCID: PMC8172241 DOI: 10.7554/elife.64013] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 05/18/2021] [Indexed: 12/12/2022] Open
Abstract
Embryonic taste bud primordia are specified as taste placodes on the tongue surface and differentiate into the first taste receptor cells (TRCs) at birth. Throughout adult life, TRCs are continually regenerated from epithelial progenitors. Sonic hedgehog (SHH) signaling regulates TRC development and renewal, repressing taste fate embryonically, but promoting TRC differentiation in adults. Here, using mouse models, we show TRC renewal initiates at birth and coincides with onset of SHHs pro-taste function. Using transcriptional profiling to explore molecular regulators of renewal, we identified Foxa1 and Foxa2 as potential SHH target genes in lingual progenitors at birth and show that SHH overexpression in vivo alters FoxA1 and FoxA2 expression relevant to taste buds. We further bioinformatically identify genes relevant to cell adhesion and cell locomotion likely regulated by FOXA1;FOXA2 and show that expression of these candidates is also altered by forced SHH expression. We present a new model where SHH promotes TRC differentiation by regulating changes in epithelial cell adhesion and migration.
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Affiliation(s)
- Erin J Golden
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Eric D Larson
- The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States.,Department of Otolaryngology, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Lauren A Shechtman
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - G Devon Trahan
- Department of Pediatrics, Section of Hematology, Oncology, and Bone Marrow Transplant, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Dany Gaillard
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Timothy J Fellin
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Jennifer K Scott
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Kenneth L Jones
- Department of Pediatrics, Section of Hematology, Oncology, and Bone Marrow Transplant, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Linda A Barlow
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, United States.,The Rocky Mountain Taste and Smell Center, University of Colorado Anschutz Medical Campus, Aurora, United States
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17
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Gaillard D, Barlow LA. A Mechanistic Overview of Taste Bud Maintenance and Impairment in Cancer Therapies. Chem Senses 2021; 46:6161548. [PMID: 33693542 DOI: 10.1093/chemse/bjab011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Since the early 20th century, progress in cancer therapies has significantly improved disease prognosis. Nonetheless, cancer treatments are often associated with side effects that can negatively affect patient well-being and disrupt the course of treatment. Among the main side effects, taste impairment is associated with depression, malnutrition, and morbid weight loss. Although relatively common, taste disruption associated with cancer therapies remains poorly understood. Here, we review the current knowledge related to the molecular mechanisms underlying taste maintenance and disruption in the context of cancer therapies.
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Affiliation(s)
- Dany Gaillard
- Department of Cell & Developmental Biology, and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, 12801 East 17th Avenue, Mail Stop 8108, Aurora, CO 80045, USA
| | - Linda A Barlow
- Department of Cell & Developmental Biology, and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, 12801 East 17th Avenue, Mail Stop 8108, Aurora, CO 80045, USA
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18
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Jensterle M, Rizzo M, Janez A. Glucagon-Like Peptide 1 and Taste Perception: From Molecular Mechanisms to Potential Clinical Implications. Int J Mol Sci 2021; 22:ijms22020902. [PMID: 33477478 PMCID: PMC7830704 DOI: 10.3390/ijms22020902] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/03/2021] [Accepted: 01/15/2021] [Indexed: 12/14/2022] Open
Abstract
Preclinical studies provided some important insights into the action of glucagon-like peptide 1 (GLP-1) in taste perception. This review examines the literature to uncover some molecular mechanisms and connections between GLP-1 and the gustatory coding. Local GLP-1 production in the taste bud cells, the expression of GLP-1 receptor on the adjacent nerves, a functional continuum in the perception of sweet chemicals from the gut to the tongue and an identification of GLP-1 induced signaling pathways in peripheral and central gustatory coding all strongly suggest that GLP-1 is involved in the taste perception, especially sweet. However, the impact of GLP-1 based therapies on gustatory coding in humans remains largely unaddressed. Based on the molecular background we encourage further exploration of the tongue as a new treatment target for GLP-1 receptor agonists in clinical studies. Given that pharmacological manipulation of gustatory coding may represent a new potential strategy against obesity and diabetes, the topic is of utmost clinical relevance.
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Affiliation(s)
- Mojca Jensterle
- Diabetes and Metabolic Diseases, Division of Internal Medicine, Department of Endocrinology, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia;
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
| | - Manfredi Rizzo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of South Carolina, Columbia, SC 29208, USA;
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University of Palermo, 90133 Palermo, Italy
| | - Andrej Janez
- Diabetes and Metabolic Diseases, Division of Internal Medicine, Department of Endocrinology, University Medical Centre Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia;
- Department of Internal Medicine, Faculty of Medicine, University of Ljubljana, Zaloška Cesta 7, 1000 Ljubljana, Slovenia
- Correspondence: ; Tel.: +386-1-522-3114; Fax: +386-1-522-9359
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19
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R-spondin substitutes for neuronal input for taste cell regeneration in adult mice. Proc Natl Acad Sci U S A 2020; 118:2001833118. [PMID: 33443181 DOI: 10.1073/pnas.2001833118] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Taste bud cells regenerate throughout life. Taste bud maintenance depends on continuous replacement of senescent taste cells with new ones generated by adult taste stem cells. More than a century ago it was shown that taste buds degenerate after their innervating nerves are transected and that they are not restored until after reinnervation by distant gustatory ganglion neurons. Thus, neuronal input, likely via neuron-supplied factors, is required for generation of differentiated taste cells and taste bud maintenance. However, the identity of such a neuron-supplied niche factor(s) remains unclear. Here, by mining a published RNA-sequencing dataset of geniculate ganglion neurons and by in situ hybridization, we demonstrate that R-spondin-2, the ligand of Lgr5 and its homologs Lgr4/6 and stem-cell-expressed E3 ligases Rnf43/Znrf3, is expressed in nodose-petrosal and geniculate ganglion neurons. Using the glossopharyngeal nerve transection model, we show that systemic delivery of R-spondin via adenovirus can promote generation of differentiated taste cells despite denervation. Thus, exogenous R-spondin can substitute for neuronal input for taste bud cell replenishment and taste bud maintenance. Using taste organoid cultures, we show that R-spondin is required for generation of differentiated taste cells and that, in the absence of R-spondin in culture medium, taste bud cells are not generated ex vivo. Thus, we propose that R-spondin-2 may be the long-sought neuronal factor that acts on taste stem cells for maintaining taste tissue homeostasis.
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20
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Tseng SCG, Chen SY, Mead OG, Tighe S. Niche regulation of limbal epithelial stem cells: HC-HA/PTX3 as surrogate matrix niche. Exp Eye Res 2020; 199:108181. [PMID: 32795525 DOI: 10.1016/j.exer.2020.108181] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/15/2020] [Accepted: 07/31/2020] [Indexed: 12/13/2022]
Abstract
Homeostasis of the corneal epithelium is ultimately maintained by stem cells that reside in a specialized microenvironment within the corneal limbus termed palisades of Vogt. This limbal niche nourishes, protects, and regulates quiescence, self-renewal, and fate decision of limbal epithelial stem/progenitor cells (LEPCs) toward corneal epithelial differentiation. This review focuses on our current understanding of the mechanism by which limbal (stromal) niche cells (LNCs) regulate the aforementioned functions of LEPCs. Based on our discovery and characterization of a unique extracellular matrix termed HC-HA/PTX3 (Heavy chain (HC1)-hyaluronan (HA)/pentraxin 3 (PTX3) complex, "-" denotes covalent linkage; "/" denotes non-covalent binding) in the birth tissue, i.e., amniotic membrane and umbilical cord, we put forth a new paradigm that HC-HA/PTX3 serves as a surrogate matrix niche by maintaining the in vivo nuclear Pax6+ neural crest progenitor phenotype to support quiescence and self-renewal but prevent corneal fate decision of LEPCs. This new paradigm helps explain how limbal stem cell deficiency (LSCD) develops in aniridia due to Pax6-haplotype deficiency and further explains why transplantation of HC-HA/PTX3-containing amniotic membrane prevents LSCD in acute chemical burns and Stevens Johnson syndrome, augments the success of autologous LEPCs transplantation in patients suffering from partial or total LSCD, and assists ex vivo expansion (engineering) of a graft containing LEPCs. We thus envisage that this new paradigm based on regenerative matrix HC-HA/PTX3 as a surrogate niche can set a new standard for regenerative medicine in and beyond ophthalmology.
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Affiliation(s)
- Scheffer C G Tseng
- Research & Development Department, TissueTech, Inc., Miami, FL, 33126, USA; Ocular Surface Center and Ocular Surface Research & Education Foundation, Miami, FL, 33126, USA.
| | - Szu-Yu Chen
- Research & Development Department, TissueTech, Inc., Miami, FL, 33126, USA
| | - Olivia G Mead
- Research & Development Department, TissueTech, Inc., Miami, FL, 33126, USA
| | - Sean Tighe
- Research & Development Department, TissueTech, Inc., Miami, FL, 33126, USA; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA; Department of Ophthalmology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
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21
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Ishan M, Chen G, Sun C, Chen SY, Komatsu Y, Mishina Y, Liu HX. Increased activity of mesenchymal ALK2-BMP signaling causes posteriorly truncated microglossia and disorganization of lingual tissues. Genesis 2020; 58:e23337. [PMID: 31571391 PMCID: PMC6980365 DOI: 10.1002/dvg.23337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 12/15/2022]
Abstract
Proper development of taste organs including the tongue and taste papillae requires interactions with the underlying mesenchyme through multiple molecular signaling pathways. The effects of bone morphogenetic proteins (BMPs) and antagonists are profound, however, the tissue-specific roles of distinct receptors are largely unknown. Here, we report that constitutive activation (ca) of ALK2-BMP signaling in the tongue mesenchyme (marked by Wnt1-Cre) caused microglossia-a dramatically smaller and misshapen tongue with a progressively severe reduction in size along the anteroposterior axis and absence of a pharyngeal region. At E10.5, the tongue primordia (branchial arches 1-4) formed in Wnt1-Cre/caAlk2 mutants while each branchial arch responded to elevated BMP signaling distinctly in gene expression of BMP targets (Id1, Snai1, Snai2, and Runx2), proliferation (Cyclin-D1) and apoptosis (p53). Moreover, elevated ALK2-BMP signaling in the mesenchyme resulted in apparent defects of lingual epithelium, muscles, and nerves. In Wnt1-Cre/caAlk2 mutants, a circumvallate papilla was missing and further development of formed fungiform papillae was arrested in late embryos. Our data collectively demonstrate that ALK2-BMP signaling in the mesenchyme plays essential roles in orchestrating various tissues for proper development of the tongue and its appendages in a region-specific manner.
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Affiliation(s)
- Mohamed Ishan
- Department of Animal and Dairy Science, Regenerative Bioscience Center, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia
| | - Guiqian Chen
- Department of Animal and Dairy Science, Regenerative Bioscience Center, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia
| | - Chenming Sun
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - Shi-You Chen
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - Yoshihiro Komatsu
- Department of Pediatrics, The University of Texas Medical School at Houston, Houston, Texas
| | - Yuji Mishina
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan
| | - Hong-Xiang Liu
- Department of Animal and Dairy Science, Regenerative Bioscience Center, College of Agricultural and Environmental Sciences, University of Georgia, Athens, Georgia
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22
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Okuhara S, Birjandi AA, Adel Al-Lami H, Sagai T, Amano T, Shiroishi T, Xavier GM, Liu KJ, Cobourne MT, Iseki S. Temporospatial sonic hedgehog signalling is essential for neural crest-dependent patterning of the intrinsic tongue musculature. Development 2019; 146:146/21/dev180075. [PMID: 31719045 DOI: 10.1242/dev.180075] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/17/2019] [Indexed: 01/20/2023]
Abstract
The tongue is a highly specialised muscular organ with a complex anatomy required for normal function. We have utilised multiple genetic approaches to investigate local temporospatial requirements for sonic hedgehog (SHH) signalling during tongue development. Mice lacking a Shh cis-enhancer, MFCS4 (ShhMFCS4/-), with reduced SHH in dorsal tongue epithelium have perturbed lingual septum tendon formation and disrupted intrinsic muscle patterning, with these defects reproduced following global Shh deletion from E10.5 in pCag-CreERTM; Shhflox/flox embryos. SHH responsiveness was diminished in local cranial neural crest cell (CNCC) populations in both mutants, with SHH targeting these cells through the primary cilium. CNCC-specific deletion of orofaciodigital syndrome 1 (Ofd1), which encodes a ciliary protein, in Wnt1-Cre; Ofdfl/Y mice led to a complete loss of normal myotube arrangement and hypoglossia. In contrast, mesoderm-specific deletion of Ofd1 in Mesp1-Cre; Ofdfl/Y embryos resulted in normal intrinsic muscle arrangement. Collectively, these findings suggest key temporospatial requirements for local SHH signalling in tongue development (specifically, lingual tendon differentiation and intrinsic muscle patterning through signalling to CNCCs) and provide further mechanistic insight into the tongue anomalies seen in patients with disrupted hedgehog signalling.
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Affiliation(s)
- Shigeru Okuhara
- Section of Molecular Craniofacial Embryology, Graduate School of Dental and Medical Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan
| | - Anahid A Birjandi
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Hadeel Adel Al-Lami
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Tomoko Sagai
- Mammalian Genetics Laboratory, National Institute of Genetics, Mishima 411-8540, Japan
| | - Takanori Amano
- Mammalian Genetics Laboratory, National Institute of Genetics, Mishima 411-8540, Japan
| | - Toshihiko Shiroishi
- Mammalian Genetics Laboratory, National Institute of Genetics, Mishima 411-8540, Japan
| | - Guilherme M Xavier
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Karen J Liu
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Martyn T Cobourne
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, London SE1 9RT, UK
| | - Sachiko Iseki
- Section of Molecular Craniofacial Embryology, Graduate School of Dental and Medical Sciences, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan
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23
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Huang AY. Immune Responses Alter Taste Perceptions: Immunomodulatory Drugs Shape Taste Signals during Treatments. J Pharmacol Exp Ther 2019; 371:684-691. [PMID: 31611237 DOI: 10.1124/jpet.119.261297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/08/2019] [Indexed: 01/01/2023] Open
Abstract
Considering that nutrients are required in health and diseases, the detection and ingestion of food to meet the requirements is attributable to the sense of taste. Altered taste sensations lead to a decreased appetite, which is usually one of the frequent causes of malnutrition in patients with diseases. Ongoing taste research has identified a variety of drug pathways that cause changes in taste perceptions in cancer, increasing our understanding of taste disturbances attributable to aberrant mechanisms of taste sensation. The evidence discussed in this review, which addresses the implications of innate immune responses in the modulation of taste functions, focuses on the adverse effects on taste transmission from taste buds by immune modulators responsible for alterations in the perceived intensity of some taste modalities. Another factor, damage to taste progenitor cells that directly results in local effects on taste buds, must also be considered in relation to taste disturbances in patients with cancer. Recent discoveries discussed have provided new insights into the pathophysiology of taste dysfunctions associated with the specific treatments. SIGNIFICANCE STATEMENT: The paradigm that taste signals transmitted to the brain are determined only by tastant-mediated activation via taste receptors has been challenged by the immune modification of taste transmission through drugs during the processing of gustatory information in taste buds. This article reports the findings in a model system (mouse taste buds) that explain the basis for the taste dysfunctions in patients with cancer that has long been observed but never understood.
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Affiliation(s)
- Anthony Y Huang
- Department of Anatomy and Center for Integrated Research in Cognitive and Neural Science, Southern Illinois University School of Medicine, Carbondale, Illinois
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24
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Fan D, Chettouh Z, Consalez GG, Brunet JF. Taste bud formation depends on taste nerves. eLife 2019; 8:e49226. [PMID: 31570121 PMCID: PMC6785267 DOI: 10.7554/elife.49226] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/23/2019] [Indexed: 01/07/2023] Open
Abstract
It has been known for more than a century that, in adult vertebrates, the maintenance of taste buds depends on their afferent nerves. However, the initial formation of taste buds is proposed to be nerve-independent in amphibians, and evidence to the contrary in mammals has been endlessly debated, mostly due to indirect and incomplete means to impede innervation during the protracted perinatal period of taste bud differentiation. Here, by genetically ablating, in mice, all somatic (i.e. touch) or visceral (i.e. taste) neurons for the oral cavity, we show that the latter but not the former are absolutely required for the proper formation of their target organs, the taste buds.
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Affiliation(s)
- Di Fan
- Institut de Biologie de l’ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research UniversityParisFrance
- School of Life ScienceEast China Normal UniversityShanghaiChina
| | - Zoubida Chettouh
- Institut de Biologie de l’ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research UniversityParisFrance
| | - G Giacomo Consalez
- San Raffaele Scientific Institute and Università Vita-Salute San RaffaeleMilanoItaly
| | - Jean-François Brunet
- Institut de Biologie de l’ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research UniversityParisFrance
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25
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Gao Y, Dutta Banik D, Muna MM, Roberts SG, Medler KF. The WT1-BASP1 complex is required to maintain the differentiated state of taste receptor cells. Life Sci Alliance 2019; 2:2/3/e201800287. [PMID: 31167803 PMCID: PMC6555901 DOI: 10.26508/lsa.201800287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 05/27/2019] [Accepted: 05/27/2019] [Indexed: 12/21/2022] Open
Abstract
The WT1/BASP1 complex is important to maintain taste receptor cells in their terminally differentiated state. WT1 is a transcriptional activator that controls the boundary between multipotency and differentiation. The transcriptional cofactor BASP1 binds to WT1, forming a transcriptional repressor complex that drives differentiation in cultured cells; however, this proposed mechanism has not been demonstrated in vivo. We used the peripheral taste system as a model to determine how BASP1 regulates the function of WT1. During development, WT1 is highly expressed in the developing taste cells while BASP1 is absent. By the end of development, BASP1 and WT1 are co-expressed in taste cells, where they both occupy the promoter of WT1 target genes. Using a conditional BASP1 mouse, we demonstrate that BASP1 is critical to maintain the differentiated state of adult taste cells and that loss of BASP1 expression significantly alters the composition and function of these cells. This includes the de-repression of WT1-dependent target genes from the Wnt and Shh pathways that are normally only transcriptionally activated by WT1 in the undifferentiated taste cells. Our results uncover a central role for the WT1–BASP1 complex in maintaining cell differentiation in vivo.
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Affiliation(s)
- Yankun Gao
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
| | | | - Mutia M Muna
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
| | - Stefan Ge Roberts
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA .,School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Kathryn F Medler
- Department of Biological Sciences, University at Buffalo, Buffalo, NY, USA
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26
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Sudiwala S, Knox SM. The emerging role of cranial nerves in shaping craniofacial development. Genesis 2019; 57:e23282. [PMID: 30628162 DOI: 10.1002/dvg.23282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/05/2019] [Accepted: 01/07/2019] [Indexed: 12/17/2022]
Abstract
Organs and structures of the vertebrate head perform a plethora of tasks including visualization, digestion, vocalization/communication, auditory functions, and respiration in response to neuronal input. This input is primarily derived from afferent and efferent fibers of the cranial nerves (sensory and motor respectively) and efferent fibers of the cervical sympathetic trunk. Despite their essential contribution to the function and integration of processes necessary for survival, how organ innervation is established remains poorly understood. Furthermore, while it has been appreciated for some time that innervation of organs by cranial nerves is regulated in part by secreted factors and cell surface ligands expressed by those organs, whether nerves also regulate the development of facial organs is only beginning to be elucidated. This review will provide an overview of cranial nerve development in relation to the organs they innervate, and outline their known contributions to craniofacial development, thereby providing insight into how nerves may shape the organs they innervate during development. Throughout, the interaction between different cell and tissue types will be highlighted.
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Affiliation(s)
- Sonia Sudiwala
- Program in Craniofacial Biology, Department of Cell and Tissue Biology, University of California, San Francisco, California
| | - Sarah M Knox
- Program in Craniofacial Biology, Department of Cell and Tissue Biology, University of California, San Francisco, California
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Hedgehog Signaling Regulates Taste Organs and Oral Sensation: Distinctive Roles in the Epithelium, Stroma, and Innervation. Int J Mol Sci 2019; 20:ijms20061341. [PMID: 30884865 PMCID: PMC6471208 DOI: 10.3390/ijms20061341] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/19/2019] [Accepted: 03/05/2019] [Indexed: 12/21/2022] Open
Abstract
The Hedgehog (Hh) pathway has regulatory roles in maintaining and restoring lingual taste organs, the papillae and taste buds, and taste sensation. Taste buds and taste nerve responses are eliminated if Hh signaling is genetically suppressed or pharmacologically inhibited, but regeneration can occur if signaling is reactivated within the lingual epithelium. Whereas Hh pathway disruption alters taste sensation, tactile and cold responses remain intact, indicating that Hh signaling is modality-specific in regulation of tongue sensation. However, although Hh regulation is essential in taste, the basic biology of pathway controls is not fully understood. With recent demonstrations that sonic hedgehog (Shh) is within both taste buds and the innervating ganglion neurons/nerve fibers, it is compelling to consider Hh signaling throughout the tongue and taste organ cell and tissue compartments. Distinctive signaling centers and niches are reviewed in taste papilla epithelium, taste buds, basal lamina, fibroblasts and lamellipodia, lingual nerves, and sensory ganglia. Several new roles for the innervation in lingual Hh signaling are proposed. Hh signaling within the lingual epithelium and an intact innervation each is necessary, but only together are sufficient to sustain and restore taste buds. Importantly, patients who use Hh pathway inhibiting drugs confront an altered chemosensory world with loss of taste buds and taste responses, intact lingual touch and cold sensation, and taste recovery after drug discontinuation.
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28
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Obesity is associated with altered gene expression in human tastebuds. Int J Obes (Lond) 2019; 43:1475-1484. [PMID: 30696932 DOI: 10.1038/s41366-018-0303-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 10/04/2018] [Accepted: 10/08/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND The role of taste perception in the development and persistence of obesity is currently unclear due to conflicting results from psychophysical and other studies. No study to date has assessed whether there is an underlying fundamental difference in the physiology of taste tissue between lean and obese individuals. METHOD/SUBJECTS We analysed the transcriptomic profile (RNA-seq) of human fungiform taste papillae biopsied from lean (n = 23) and obese (n = 13) Caucasian females (age range 18-55) to identify differences in gene expression. RESULTS Obesity status was the major contributor to variance in global gene expression between individuals. A total of 62 genes had significantly different gene expression levels between lean and obese (P < 0.0002), with the specific taste associated genes phospholipase C beta 2 (PLCβ2) and sonic hedge-hog (SHH) having significantly reduced expression in obese group. Genes associated with inflammation and immune response were the top enriched biological pathways differing between the lean and the obese groups. Analysis of a broader gene set having a twofold change in expression (2619 genes) identified three enriched theme groups (sensory perception, cell and synaptic signalling, and immune response). Further, analysis of taste associated genes identified a consistent reduction in the expression of taste-related genes (in particular reduced type II taste cell genes) in the obese compared to the lean group. CONCLUSION The findings show obesity is associated with altered gene expression in tastebuds. Furthermore, the results suggest the tastebud microenvironment is distinctly different between lean and obese persons and, that changes in sensory gene expression contribute to this altered microenvironment. This research provides new evidence of a link between obesity and altered taste and in the future may help design strategies to combat obesity.
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29
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Zheng X, Xu X, He JZ, Zhang P, Chen J, Zhou XD. [Development and homeostasis of taste buds in mammals]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2018; 36:552-558. [PMID: 30465351 DOI: 10.7518/hxkq.2018.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Taste is mediated by multicellular taste buds distributed throughout the oral and pharyngeal cavities. The taste buds can detect five basic tastes: sour, sweet, bitter, salty and umami, allowing mammals to select nutritious foods and avoid the ingestion of toxic and rotten foods. Once developed, the taste buds undergo continuous renewal throughout the adult life. In the past decade, significant progress has been achived in delineating the cellular and molecular mechanisms governing taste buds development and homeostasis. With this knowledges and in-depth investigations in the future, we can achieve the precise management of taste dysfunctions such as dysgeusia and ageusia.
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Affiliation(s)
- Xin Zheng
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xin Xu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jin-Zhi He
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Ping Zhang
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jiao Chen
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xue-Dong Zhou
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & Dept. of Conservative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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30
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Castillo-Azofeifa D, Seidel K, Gross L, Golden EJ, Jacquez B, Klein OD, Barlow LA. SOX2 regulation by hedgehog signaling controls adult lingual epithelium homeostasis. Development 2018; 145:dev.164889. [PMID: 29945863 DOI: 10.1242/dev.164889] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
Adult tongue epithelium is continuously renewed from epithelial progenitor cells, a process that requires hedgehog (HH) signaling. In mice, pharmacological inhibition of the HH pathway causes taste bud loss within a few weeks. Previously, we demonstrated that sonic hedgehog (SHH) overexpression in lingual progenitors induces ectopic taste buds with locally increased SOX2 expression, suggesting that taste bud differentiation depends on SOX2 downstream of HH. To test this, we inhibited HH signaling in mice and observed a rapid decline in Sox2 and SOX2-GFP expression in taste epithelium. Upon conditional deletion of Sox2, differentiation of both taste and non-taste epithelial cells was blocked, and progenitor cell number increased. In contrast to basally restricted proliferation in controls, dividing cells were overabundant and spread to suprabasal epithelial layers in mutants. SOX2 loss in progenitors also led non-cell-autonomously to taste cell apoptosis, dramatically shortening taste cell lifespans. Finally, in tongues with conditional Sox2 deletion and SHH overexpression, ectopic and endogenous taste buds were not detectable; instead, progenitor hyperproliferation expanded throughout the lingual epithelium. In summary, we show that SOX2 functions downstream of HH signaling to regulate lingual epithelium homeostasis.
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Affiliation(s)
- David Castillo-Azofeifa
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Rocky Mountain Taste and Smell Center, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Kerstin Seidel
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA 94131, USA
| | - Lauren Gross
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Erin J Golden
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Belkis Jacquez
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,BRAIN Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ophir D Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA 94131, USA.,Department of Pediatrics, University of California San Francisco, San Francisco, CA 94131, USA.,Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94131, USA
| | - Linda A Barlow
- Department of Cell and Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA .,Rocky Mountain Taste and Smell Center, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,BRAIN Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
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31
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Qin Y, Sukumaran SK, Jyotaki M, Redding K, Jiang P, Margolskee RF. Gli3 is a negative regulator of Tas1r3-expressing taste cells. PLoS Genet 2018; 14:e1007058. [PMID: 29415007 PMCID: PMC5819828 DOI: 10.1371/journal.pgen.1007058] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 02/20/2018] [Accepted: 10/08/2017] [Indexed: 12/25/2022] Open
Abstract
Mouse taste receptor cells survive from 3-24 days, necessitating their regeneration throughout adulthood. In anterior tongue, sonic hedgehog (SHH), released by a subpopulation of basal taste cells, regulates transcription factors Gli2 and Gli3 in stem cells to control taste cell regeneration. Using single-cell RNA-Seq we found that Gli3 is highly expressed in Tas1r3-expressing taste receptor cells and Lgr5+ taste stem cells in posterior tongue. By PCR and immunohistochemistry we found that Gli3 was expressed in taste buds in all taste fields. Conditional knockout mice lacking Gli3 in the posterior tongue (Gli3CKO) had larger taste buds containing more taste cells than did control wild-type (Gli3WT) mice. In comparison to wild-type mice, Gli3CKO mice had more Lgr5+ and Tas1r3+ cells, but fewer type III cells. Similar changes were observed ex vivo in Gli3CKO taste organoids cultured from Lgr5+ taste stem cells. Further, the expression of several taste marker and Gli3 target genes was altered in Gli3CKO mice and/or organoids. Mirroring these changes, Gli3CKO mice had increased lick responses to sweet and umami stimuli, decreased lick responses to bitter and sour taste stimuli, and increased glossopharyngeal taste nerve responses to sweet and bitter compounds. Our results indicate that Gli3 is a suppressor of stem cell proliferation that affects the number and function of mature taste cells, especially Tas1r3+ cells, in adult posterior tongue. Our findings shed light on the role of the Shh pathway in adult taste cell regeneration and may help devise strategies for treating taste distortions from chemotherapy and aging.
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Affiliation(s)
- Yumei Qin
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
- School of Food Science and Biotechnology, Zhejiang Gonshang University, Hangzhou, Zhejiang, China
| | - Sunil K. Sukumaran
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
| | - Masafumi Jyotaki
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
| | - Kevin Redding
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
| | - Peihua Jiang
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
| | - Robert F. Margolskee
- Monell Chemical Senses Center, Philadelphia, Pennsylvania, United States of America
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32
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Lu WJ, Mann RK, Nguyen A, Bi T, Silverstein M, Tang JY, Chen X, Beachy PA. Neuronal delivery of Hedgehog directs spatial patterning of taste organ regeneration. Proc Natl Acad Sci U S A 2018; 115:E200-E209. [PMID: 29279401 PMCID: PMC5777079 DOI: 10.1073/pnas.1719109115] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
How organs maintain and restore functional integrity during ordinary tissue turnover or following injury represents a central biological problem. The maintenance of taste sensory organs in the tongue was shown 140 years ago to depend on innervation from distant ganglion neurons, but the underlying mechanism has remained unknown. Here, we show that Sonic hedgehog (Shh), which encodes a secreted protein signal, is expressed in these sensory neurons, and that experimental ablation of neuronal Shh expression causes loss of taste receptor cells (TRCs). TRCs are also lost upon pharmacologic blockade of Hedgehog pathway response, accounting for the loss of taste sensation experienced by cancer patients undergoing Hedgehog inhibitor treatment. We find that TRC regeneration following such pharmacologic ablation requires neuronal expression of Shh and can be substantially enhanced by pharmacologic activation of Hedgehog response. Such pharmacologic enhancement of Hedgehog response, however, results in additional TRC formation at many ectopic sites, unlike the site-restricted regeneration specified by the projection pattern of Shh-expressing neurons. Stable regeneration of TRCs thus requires neuronal Shh, illustrating the principle that neuronal delivery of cues such as the Shh signal can pattern distant cellular responses to assure functional integrity during tissue maintenance and regeneration.
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Affiliation(s)
- Wan-Jin Lu
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305;
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305
| | - Randall K Mann
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305
| | - Allison Nguyen
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305
| | - Tingting Bi
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305
| | - Max Silverstein
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305
| | - Jean Y Tang
- Department of Dermatology, Stanford University School of Medicine, Stanford, CA 94305
| | - Xiaoke Chen
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Philip A Beachy
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305;
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305
- Department of Developmental Biology, Stanford University, Stanford, CA 94305
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305
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33
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Marshall KL, Clary RC, Baba Y, Orlowsky RL, Gerling GJ, Lumpkin EA. Touch Receptors Undergo Rapid Remodeling in Healthy Skin. Cell Rep 2017; 17:1719-1727. [PMID: 27829143 DOI: 10.1016/j.celrep.2016.10.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/21/2016] [Accepted: 10/12/2016] [Indexed: 11/24/2022] Open
Abstract
Sensory tissues exposed to the environment, such as skin, olfactory epithelia, and taste buds, continuously renew; therefore, peripheral neurons must have mechanisms to maintain appropriate innervation patterns. Although somatosensory neurons regenerate after injury, little is known about how these neurons cope with normal target organ changes. To elucidate neuronal plasticity in healthy skin, we analyzed the structure of Merkel-cell afferents, which are gentle touch receptors, during skin remodeling that accompanies mouse hair-follicle regeneration. The number of Merkel cells is reduced by 90% and axonal arbors are simplified during active hair growth. These structures rebound within just days. Computational modeling predicts that Merkel-cell changes are probabilistic, but myelinated branch stability depends on Merkel-cell inputs. Electrophysiology and behavior demonstrate that tactile responsiveness is less reliable during active growth than in resting skin. These results reveal that somatosensory neurons display structural plasticity at the cost of impairment in the reliability of encoding gentle touch.
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Affiliation(s)
- Kara L Marshall
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Integrated Training Program in Cellular, Molecular and Biomedical Sciences, Columbia University, New York, NY 10032, USA
| | - Rachel C Clary
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Neurobiology and Behavior Training Program, Columbia University, New York, NY 10032, USA
| | - Yoshichika Baba
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA
| | - Rachel L Orlowsky
- Department of Systems and Information Engineering, University of Virginia, Charlottesville, VA 22904, USA; Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Gregory J Gerling
- Department of Systems and Information Engineering, University of Virginia, Charlottesville, VA 22904, USA; Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22904, USA
| | - Ellen A Lumpkin
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032, USA; Integrated Training Program in Cellular, Molecular and Biomedical Sciences, Columbia University, New York, NY 10032, USA; Neurobiology and Behavior Training Program, Columbia University, New York, NY 10032, USA; Department of Dermatology, Columbia University, New York, NY 10032, USA.
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34
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Recovery of taste organs and sensory function after severe loss from Hedgehog/Smoothened inhibition with cancer drug sonidegib. Proc Natl Acad Sci U S A 2017; 114:E10369-E10378. [PMID: 29133390 DOI: 10.1073/pnas.1712881114] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Striking taste disturbances are reported in cancer patients treated with Hedgehog (HH)-pathway inhibitor drugs, including sonidegib (LDE225), which block the HH pathway effector Smoothened (SMO). We tested the potential for molecular, cellular, and functional recovery in mice from the severe disruption of taste-organ biology and taste sensation that follows HH/SMO signaling inhibition. Sonidegib treatment led to rapid loss of taste buds (TB) in both fungiform and circumvallate papillae, including disruption of TB progenitor-cell proliferation and differentiation. Effects were selective, sparing nontaste papillae. To confirm that taste-organ effects of sonidegib treatment result from HH/SMO signaling inhibition, we studied mice with conditional global or epithelium-specific Smo deletions and observed similar effects. During sonidegib treatment, chorda tympani nerve responses to lingual chemical stimulation were maintained at 10 d but were eliminated after 16 d, associated with nearly complete TB loss. Notably, responses to tactile or cold stimulus modalities were retained. Further, innervation, which was maintained in the papilla core throughout treatment, was not sufficient to sustain TB during HH/SMO inhibition. Importantly, treatment cessation led to rapid and complete restoration of taste responses within 14 d associated with morphologic recovery in about 55% of TB. However, although taste nerve responses were sustained, TB were not restored in all fungiform papillae even with prolonged recovery for several months. This study establishes a physiologic, selective requirement for HH/SMO signaling in taste homeostasis that includes potential for sensory restoration and can explain the temporal recovery after taste dysgeusia in patients treated with HH/SMO inhibitors.
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35
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Mukherjee N, Pal Choudhuri S, Delay RJ, Delay ER. Cellular mechanisms of cyclophosphamide-induced taste loss in mice. PLoS One 2017; 12:e0185473. [PMID: 28950008 PMCID: PMC5614555 DOI: 10.1371/journal.pone.0185473] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 09/13/2017] [Indexed: 11/18/2022] Open
Abstract
Many commonly prescribed chemotherapy drugs such as cyclophosphamide (CYP) have adverse side effects including disruptions in taste which can result in loss of appetite, malnutrition, poorer recovery and reduced quality of life. Previous studies in mice found evidence that CYP has a two-phase disturbance in taste behavior: a disturbance immediately following drug administration and a second which emerges several days later. In this study, we examined the processes by which CYP disturbs the taste system by examining the effects of the drug on taste buds and cells responsible for taste cell renewal using immunohistochemical assays. Data reported here suggest CYP has direct cytotoxic effects on lingual epithelium immediately following administration, causing an early loss of taste sensory cells. Types II and III cells in fungiform taste buds appear to be more susceptible to this effect than circumvallate cells. In addition, CYP disrupts the population of rapidly dividing cells in the basal layer of taste epithelium responsible for taste cell renewal, manifesting a disturbance days later. The loss of these cells temporarily retards the system’s capacity to replace Type II and Type III taste sensory cells that survived the cytotoxic effects of CYP and died at the end of their natural lifespan. The timing of an immediate, direct loss of taste cells and a delayed, indirect loss without replacement of taste sensory cells are broadly congruent with previously published behavioral data reporting two periods of elevated detection thresholds for umami and sucrose stimuli. These findings suggest that chemotherapeutic disturbances in the peripheral mechanisms of the taste system may cause dietary challenges at a time when the cancer patient has significant need for well balanced, high energy nutritional intake.
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Affiliation(s)
- Nabanita Mukherjee
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, Vermont, United States of America
| | - Shreoshi Pal Choudhuri
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, Vermont, United States of America
| | - Rona J. Delay
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, Vermont, United States of America
| | - Eugene R. Delay
- Department of Biology and Vermont Chemosensory Group, University of Vermont, Burlington, Vermont, United States of America
- * E-mail:
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36
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Ohman-Gault L, Huang T, Krimm R. The transcription factor Phox2b distinguishes between oral and non-oral sensory neurons in the geniculate ganglion. J Comp Neurol 2017; 525:3935-3950. [PMID: 28856690 DOI: 10.1002/cne.24312] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/04/2017] [Accepted: 08/08/2017] [Indexed: 02/01/2023]
Abstract
Many basic characteristics of gustatory neurons remain unknown, partly due to the absence of specific markers. Some neurons in the geniculate ganglion project to taste regions in the oral cavity, whereas others innervate the outer ear. We hypothesized that the transcription factor Phox2b would identify oral cavity-projecting neurons in the geniculate ganglion. To test this possibility, we characterized mice in which Phox2b-Cre mediated gene recombination labeled neurons with tdTomato. Nerve labeling revealed that all taste neurons projecting through the chorda tympani (27%) and greater superficial petrosal nerves (15%) expressed Phox2b during development, whereas non-oral somatosensory neurons (58%) in the geniculate ganglion did not. We found tdTomato-positive innervation within all taste buds. Most (57%) of the fungiform papillae had labeled innervation only in taste buds, whereas 43% of the fungiform papillae also had additional labeled innervation to the papilla epithelium. Chorda tympani nerve transection eliminated all labeled innervation to taste buds, but most of the additional innervation in the fungiform papillae remained. Some of these additional fibers also expressed tyrosine hydroxylase, suggesting a sympathetic origin. Consistent with this, both sympathetic and parasympathetic fibers innervating blood vessels and salivary glands contained tdTomato labeling. Phox2b-tdTomato labels nerve fascicles in the tongue of the developing embryo and demonstrates a similar stereotyped branching pattern DiI-labeling.
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Affiliation(s)
- Lisa Ohman-Gault
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Tao Huang
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Robin Krimm
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
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37
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Gaillard D, Bowles SG, Salcedo E, Xu M, Millar SE, Barlow LA. β-catenin is required for taste bud cell renewal and behavioral taste perception in adult mice. PLoS Genet 2017; 13:e1006990. [PMID: 28846687 PMCID: PMC5591015 DOI: 10.1371/journal.pgen.1006990] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 09/08/2017] [Accepted: 08/21/2017] [Indexed: 02/07/2023] Open
Abstract
Taste stimuli are transduced by taste buds and transmitted to the brain via afferent gustatory fibers. Renewal of taste receptor cells from actively dividing progenitors is finely tuned to maintain taste sensitivity throughout life. We show that conditional β-catenin deletion in mouse taste progenitors leads to rapid depletion of progenitors and Shh+ precursors, which in turn causes taste bud loss, followed by loss of gustatory nerve fibers. In addition, our data suggest LEF1, TCF7 and Wnt3 are involved in a Wnt pathway regulatory feedback loop that controls taste cell renewal in the circumvallate papilla epithelium. Unexpectedly, taste bud decline is greater in the anterior tongue and palate than in the posterior tongue. Mutant mice with this regional pattern of taste bud loss were unable to discern sweet at any concentration, but could distinguish bitter stimuli, albeit with reduced sensitivity. Our findings are consistent with published reports wherein anterior taste buds have higher sweet sensitivity while posterior taste buds are better tuned to bitter, and suggest β-catenin plays a greater role in renewal of anterior versus posterior taste buds. By remaining relatively constant throughout adult life, the sense of taste helps keep the body healthy. However, taste perception can be disrupted by various environmental factors, including cancer therapies. Here, we show that Wnt/β-catenin signaling, a pathway known to control normal tissue maintenance and associated with the development of cancers, is required for taste cell renewal and behavioral taste sensitivity in mice. Our findings are significant as they suggest that chemotherapies targeting the Wnt pathway in cancerous tissues may cause taste dysfunction and further diminish the quality of life of patients.
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Affiliation(s)
- Dany Gaillard
- Department of Cell & Developmental Biology and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Spencer G. Bowles
- Department of Cell & Developmental Biology and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Ernesto Salcedo
- Department of Cell & Developmental Biology and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Mingang Xu
- Departments of Dermatology and Cell & Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sarah E. Millar
- Departments of Dermatology and Cell & Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Linda A. Barlow
- Department of Cell & Developmental Biology and the Rocky Mountain Taste & Smell Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- * E-mail:
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38
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Castillo-Azofeifa D, Losacco JT, Salcedo E, Golden EJ, Finger TE, Barlow LA. Sonic hedgehog from both nerves and epithelium is a key trophic factor for taste bud maintenance. Development 2017; 144:3054-3065. [PMID: 28743797 DOI: 10.1242/dev.150342] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 07/13/2017] [Indexed: 01/10/2023]
Abstract
The integrity of taste buds is intimately dependent on an intact gustatory innervation, yet the molecular nature of this dependency is unknown. Here, we show that differentiation of new taste bud cells, but not progenitor proliferation, is interrupted in mice treated with a hedgehog (Hh) pathway inhibitor (HPI), and that gustatory nerves are a source of sonic hedgehog (Shh) for taste bud renewal. Additionally, epithelial taste precursor cells express Shh transiently, and provide a local supply of Hh ligand that supports taste cell renewal. Taste buds are minimally affected when Shh is lost from either tissue source. However, when both the epithelial and neural supply of Shh are removed, taste buds largely disappear. We conclude Shh supplied by taste nerves and local taste epithelium act in concert to support continued taste bud differentiation. However, although neurally derived Shh is in part responsible for the dependence of taste cell renewal on gustatory innervation, neurotrophic support of taste buds likely involves a complex set of factors.
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Affiliation(s)
- David Castillo-Azofeifa
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Justin T Losacco
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ernesto Salcedo
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Erin J Golden
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thomas E Finger
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Linda A Barlow
- Department of Cell and Developmental Biology and the Rocky Mountain Taste and Smell Center University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA .,Graduate Program in Cell Biology, Stem Cells and Development, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.,Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
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39
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Abstract
Taste cells undergo constant turnover throughout life; however, the molecular mechanisms governing taste cell generation are not well understood. Using RNA-Seq, we systematically surveyed the transcriptome landscape of taste organoids at different stages of growth. Our data show the staged expression of a variety of genes and identify multiple signaling pathways underlying taste cell differentiation and taste stem/progenitor cell proliferation. For example, transcripts of taste receptors appear only or predominantly in late-stage organoids. Prior to that, transcription factors and other signaling elements are upregulated. RNA-Seq identified a number of well-characterized signaling pathways in taste organoid cultures, such as those involving Wnt, bone morphogenetic proteins (BMPs), Notch, and Hedgehog (Hh). By pharmacological manipulation, we demonstrate that Wnt, BMPs, Notch, and Hh signaling pathways are necessary for taste cell proliferation, differentiation and cell fate determination. The temporal expression profiles displayed by taste organoids may also lead to the identification of currently unknown transducer elements underlying sour, salt, and other taste qualities, given the staged expression of taste receptor genes and taste transduction elements in cultured organoids.
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40
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Meng L, Huang T, Sun C, Hill DL, Krimm R. BDNF is required for taste axon regeneration following unilateral chorda tympani nerve section. Exp Neurol 2017; 293:27-42. [PMID: 28347764 DOI: 10.1016/j.expneurol.2017.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/22/2017] [Accepted: 03/23/2017] [Indexed: 12/18/2022]
Abstract
Taste nerves readily regenerate to reinnervate denervated taste buds; however, factors required for regeneration have not yet been identified. When the chorda tympani nerve is sectioned, expression of brain-derived neurotrophic factor (BDNF) remains high in the geniculate ganglion and lingual epithelium, despite the loss of taste buds. These observations suggest that BDNF is present in the taste system after nerve section and may support taste nerve regeneration. To test this hypothesis, we inducibly deleted Bdnf during adulthood in mice. Shortly after Bdnf gene recombination, the chorda tympani nerve was unilaterally sectioned causing a loss of both taste buds and neurons, irrespective of BDNF levels. Eight weeks after nerve section, however, regeneration was differentially affected by Bdnf deletion. In control mice, there was regeneration of the chorda tympani nerve and taste buds reappeared with innervation. In contrast, few taste buds were reinnervated in mice lacking normal Bdnf expression such that taste bud number remained low. In all genotypes, taste buds that were reinnervated were normal-sized, but non-innervated taste buds remained small and atrophic. On the side of the tongue contralateral to the nerve section, taste buds for some genotypes became larger and all taste buds remained innervated. Our findings suggest that BDNF is required for nerve regeneration following gustatory nerve section.
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Affiliation(s)
- Lingbin Meng
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA
| | - Tao Huang
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA
| | - Chengsan Sun
- Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA
| | - David L Hill
- Department of Psychology, University of Virginia, Charlottesville, VA 22904, USA
| | - Robin Krimm
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA.
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41
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Abstract
The tongue is an elaborate complex of heterogeneous tissues with taste organs of diverse embryonic origins. The lingual taste organs are papillae, composed of an epithelium that includes specialized taste buds, the basal lamina, and a lamina propria core with matrix molecules, fibroblasts, nerves, and vessels. Because taste organs are dynamic in cell biology and sensory function, homeostasis requires tight regulation in specific compartments or niches. Recently, the Hedgehog (Hh) pathway has emerged as an essential regulator that maintains lingual taste papillae, taste bud and progenitor cell proliferation and differentiation, and neurophysiological function. Activating or suppressing Hh signaling, with genetic models or pharmacological agents used in cancer treatments, disrupts taste papilla and taste bud integrity and can eliminate responses from taste nerves to chemical stimuli but not to touch or temperature. Understanding Hh regulation of taste organ homeostasis contributes knowledge about the basic biology underlying taste disruptions in patients treated with Hh pathway inhibitors.
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Affiliation(s)
- Charlotte M Mistretta
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan 48109;
| | - Archana Kumari
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan 48109;
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42
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Henkin RI, Knöppel AB, Abdelmeguid M, Stateman WA, Hosein S. Sonic hedgehog is present in parotid saliva and is decreased in patients with taste dysfunction. J Oral Pathol Med 2017; 46:829-833. [DOI: 10.1111/jop.12541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2016] [Indexed: 12/01/2022]
Affiliation(s)
- Robert I. Henkin
- Center for Molecular Nutrition and Sensory Disorders; The Taste and Smell Clinic; Washington DC USA
| | - Alexandra B. Knöppel
- Center for Molecular Nutrition and Sensory Disorders; The Taste and Smell Clinic; Washington DC USA
| | - Mona Abdelmeguid
- Center for Molecular Nutrition and Sensory Disorders; The Taste and Smell Clinic; Washington DC USA
| | - William A. Stateman
- Center for Molecular Nutrition and Sensory Disorders; The Taste and Smell Clinic; Washington DC USA
| | - Suzanna Hosein
- Center for Molecular Nutrition and Sensory Disorders; The Taste and Smell Clinic; Washington DC USA
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43
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Kiecker C, Graham A, Logan M. Differential Cellular Responses to Hedgehog Signalling in Vertebrates-What is the Role of Competence? J Dev Biol 2016; 4:jdb4040036. [PMID: 29615599 PMCID: PMC5831800 DOI: 10.3390/jdb4040036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/24/2016] [Accepted: 12/01/2016] [Indexed: 12/21/2022] Open
Abstract
A surprisingly small number of signalling pathways generate a plethora of cellular responses ranging from the acquisition of multiple cell fates to proliferation, differentiation, morphogenesis and cell death. These diverse responses may be due to the dose-dependent activities of signalling factors, or to intrinsic differences in the response of cells to a given signal—a phenomenon called differential cellular competence. In this review, we focus on temporal and spatial differences in competence for Hedgehog (HH) signalling, a signalling pathway that is reiteratively employed in embryos and adult organisms. We discuss the upstream signals and mechanisms that may establish differential competence for HHs in a range of different tissues. We argue that the changing competence for HH signalling provides a four-dimensional framework for the interpretation of the signal that is essential for the emergence of functional anatomy. A number of diseases—including several types of cancer—are caused by malfunctions of the HH pathway. A better understanding of what provides differential competence for this signal may reveal HH-related disease mechanisms and equip us with more specific tools to manipulate HH signalling in the clinic.
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Affiliation(s)
- Clemens Kiecker
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Anthony Graham
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Malcolm Logan
- Randall Division of Cell & Molecular Biophysics, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
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44
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Ermilov AN, Kumari A, Li L, Joiner AM, Grachtchouk MA, Allen BL, Dlugosz AA, Mistretta CM. Maintenance of Taste Organs Is Strictly Dependent on Epithelial Hedgehog/GLI Signaling. PLoS Genet 2016; 12:e1006442. [PMID: 27893742 PMCID: PMC5125561 DOI: 10.1371/journal.pgen.1006442] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/21/2016] [Indexed: 12/12/2022] Open
Abstract
For homeostasis, lingual taste papilla organs require regulation of epithelial cell survival and renewal, with sustained innervation and stromal interactions. To investigate a role for Hedgehog/GLI signaling in adult taste organs we used a panel of conditional mouse models to manipulate GLI activity within epithelial cells of the fungiform and circumvallate papillae. Hedgehog signaling suppression rapidly led to taste bud loss, papilla disruption, and decreased proliferation in domains of papilla epithelium that contribute to taste cells. Hedgehog responding cells were eliminated from the epithelium but retained in the papilla stromal core. Despite papilla disruption and loss of taste buds that are a major source of Hedgehog ligand, innervation to taste papillae was maintained, and not misdirected, even after prolonged GLI blockade. Further, vimentin-positive fibroblasts remained in the papilla core. However, retained innervation and stromal cells were not sufficient to maintain taste bud cells in the context of compromised epithelial Hedgehog signaling. Importantly taste organ disruption after GLI blockade was reversible in papillae that retained some taste bud cell remnants where reactivation of Hedgehog signaling led to regeneration of papilla epithelium and taste buds. Therefore, taste bud progenitors were either retained during epithelial GLI blockade or readily repopulated during recovery, and were poised to regenerate taste buds once Hedgehog signaling was restored, with innervation and papilla connective tissue elements in place. Our data argue that Hedgehog signaling is essential for adult tongue tissue maintenance and that taste papilla epithelial cells represent the key targets for physiologic Hedgehog-dependent regulation of taste organ homeostasis. Because disruption of GLI transcriptional activity in taste papilla epithelium is sufficient to drive taste organ loss, similar to pharmacologic Hedgehog pathway inhibition, the findings suggest that taste alterations in cancer patients using systemic Hedgehog pathway inhibitors result principally from interruption of signaling activity in taste papillae.
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Affiliation(s)
- Alexandre N Ermilov
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Archana Kumari
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Libo Li
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Ariell M Joiner
- Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marina A Grachtchouk
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrzej A Dlugosz
- Department of Dermatology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America.,Department of Cell and Developmental Biology, Medical School, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Charlotte M Mistretta
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America
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45
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Collier NJ, Ali FR, Lear JT. The safety and efficacy of sonidegib for the treatment of locally advanced basal cell carcinoma. Expert Rev Anticancer Ther 2016; 16:1011-8. [DOI: 10.1080/14737140.2016.1230020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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46
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Huang AY, Wu SY. The effect of imiquimod on taste bud calcium transients and transmitter secretion. Br J Pharmacol 2016; 173:3121-3133. [PMID: 27464850 DOI: 10.1111/bph.13567] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/07/2016] [Accepted: 07/19/2016] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Imiquimod is an immunomodulator approved for the treatment of basal cell carcinoma and has adverse side effects, including taste disturbances. Paracrine transmission, representing cell-cell communication within taste buds, has the potential to shape the final signals that taste buds transmit to the brain. Here, we tested the underlying assumption that imiquimod modifies taste transmitter secretion in taste buds of mice. EXPERIMENTAL APPROACH Taste buds were isolated from C57BL/6J mice. The effects of imiquimod on transmitter release in taste buds were measured using calcium imaging with cellular biosensors, and examining the net effect of imiquimod on taste-evoked ATP secretion from mouse taste buds. KEY RESULTS Up to 72% of presynaptic (Type III) taste cells responded to 100 μM imiquimod with an increase in intracellular Ca2+ concentrations. These Ca2+ responses were inhibited by thapsigargin, an inhibitor of the sarco/endoplasmic reticulum Ca2+ -ATPase, and by U73122, a PLC inhibitor, suggesting that the Ca2+ mobilization elicited by imiquimod was dependent on release from internal Ca2+ stores. Moreover, combining studies of Ca2+ imaging with cellular biosensors showed that imiquimod evoked secretion of 5-HT, which then provided negative feedback onto receptor (Type II) cells to reduce taste-evoked ATP secretion. CONCLUSION AND IMPLICATIONS Our results provide evidence that there is a subset of taste cells equipped with a range of intracellular mechanisms that respond to imiquimod. The findings are also consistent with a role of imiquimod as an immune response modifier, which shapes peripheral taste responses via 5-HT signalling.
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Affiliation(s)
- Anthony Y Huang
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA. .,Center for Integrated Research in Cognitive and Neural Science, Southern Illinois University School of Medicine, Carbondale, IL, USA.
| | - Sandy Y Wu
- Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA
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47
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Yuan G, Singh G, Chen S, Perez KC, Wu Y, Liu B, Helms JA. Cleft Palate and Aglossia Result From Perturbations in Wnt and Hedgehog Signaling. Cleft Palate Craniofac J 2016; 54:269-280. [PMID: 27259005 DOI: 10.1597/15-178] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE The objective of this study was to explore the molecular basis for cleft secondary palate and arrested tongue development caused by the loss of the intraflagellar transport protein, Kif3a. DESIGN Kif3a mutant embryos and their littermate controls were analyzed for defects in facial development at multiple stages of embryonic development. Histology was employed to understand the effects of Kif3a deletion on palate and tongue development. Various transgenic reporter strains were used to understand how deletion of Kif3a affected Hedgehog and Wnt signaling. Immunostaining for structural elements of the tongue and for components of the Wnt pathway were performed. BrdU activity analyses were carried out to examine how the loss of Kif3a affected cell proliferation and led to palate and tongue malformations. RESULTS Kif3a deletion causes cranial neural crest cells to become unresponsive to Hedgehog signals and hyper-responsive to Wnt signals. This aberrant molecular signaling causes abnormally high cell proliferation, but paradoxically outgrowths of the tongue and the palatal processes are reduced. The basis for this enigmatic effect can be traced back to a disruption in epithelial/mesenchymal signaling that governs facial development. CONCLUSION The primary cilium is a cell surface organelle that integrates Hh and Wnt signaling, and disruptions in the function of the primary cilium cause one of the most common-of the rarest-craniofacial birth defects observed in humans. The shared molecular basis for these dysmorphologies is an abnormally high Wnt signal simultaneous with an abnormally low Hedgehog signal. These pathways are integrated in the primary cilium.
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48
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Abstract
The sense of taste, or gustation, is mediated by taste buds, which are housed in specialized taste papillae found in a stereotyped pattern on the surface of the tongue. Each bud, regardless of its location, is a collection of ∼100 cells that belong to at least five different functional classes, which transduce sweet, bitter, salt, sour and umami (the taste of glutamate) signals. Taste receptor cells harbor functional similarities to neurons but, like epithelial cells, are rapidly and continuously renewed throughout adult life. Here, I review recent advances in our understanding of how the pattern of taste buds is established in embryos and discuss the cellular and molecular mechanisms governing taste cell turnover. I also highlight how these findings aid our understanding of how and why many cancer therapies result in taste dysfunction.
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Affiliation(s)
- Linda A Barlow
- Department of Cell and Developmental Biology, Graduate Program in Cell Biology, Stem Cells and Development and the Rocky Mountain Taste and Smell Center, University of Colorado, School Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
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49
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Adameyko I, Fried K. The Nervous System Orchestrates and Integrates Craniofacial Development: A Review. Front Physiol 2016; 7:49. [PMID: 26924989 PMCID: PMC4759458 DOI: 10.3389/fphys.2016.00049] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 02/02/2016] [Indexed: 01/14/2023] Open
Abstract
Development of a head is a dazzlingly complex process: a number of distinct cellular sources including cranial ecto- and endoderm, mesoderm and neural crest contribute to facial and other structures. In the head, an extremely fine-tuned developmental coordination of CNS, peripheral neural components, sensory organs and a musculo-skeletal apparatus occurs, which provides protection and functional integration. The face can to a large extent be considered as an assembly of sensory systems encased and functionally fused with appendages represented by jaws. Here we review how the developing brain, neurogenic placodes and peripheral nerves influence the morphogenesis of surrounding tissues as a part of various general integrative processes in the head. The mechanisms of this impact, as we understand it now, span from the targeted release of the morphogens necessary for shaping to providing a niche for cellular sources required in later development. In this review we also discuss the most recent findings and ideas related to how peripheral nerves and nerve-associated cells contribute to craniofacial development, including teeth, during the post- neural crest period and potentially in regeneration.
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Affiliation(s)
- Igor Adameyko
- Department of Physiology and Pharmacology, Karolinska InstitutetStockholm, Sweden; Department of Molecular Neurosciences, Center of Brain Research, Medical University of ViennaVienna, Austria
| | - Kaj Fried
- Department of Neuroscience, Karolinska Institutet Stockholm, Sweden
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50
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Recent Advances in Molecular Mechanisms of Taste Signaling and Modifying. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 323:71-106. [PMID: 26944619 DOI: 10.1016/bs.ircmb.2015.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The sense of taste conveys crucial information about the quality and nutritional value of foods before it is ingested. Taste signaling begins with taste cells via taste receptors in oral cavity. Activation of these receptors drives the transduction systems in taste receptor cells. Then particular transmitters are released from the taste cells and activate corresponding afferent gustatory nerve fibers. Recent studies have revealed that taste sensitivities are defined by distinct taste receptors and modulated by endogenous humoral factors in a specific group of taste cells. Such peripheral taste generations and modifications would directly influence intake of nutritive substances. This review will highlight current understanding of molecular mechanisms for taste reception, signal transduction in taste bud cells, transmission between taste cells and nerves, regeneration from taste stem cells, and modification by humoral factors at peripheral taste organs.
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