scholarly journals Insulin Is Transcribed and Translated in Mammalian Taste Bud Cells

Endocrinology ◽  
2018 ◽  
Vol 159 (9) ◽  
pp. 3331-3339 ◽  
Author(s):  
Máire E Doyle ◽  
Jennifer L Fiori ◽  
Isabel Gonzalez Mariscal ◽  
Qing-Rong Liu ◽  
Erin Goodstein ◽  
...  
Keyword(s):  
Green Fluorescence Protein ◽  
Taste Buds ◽  
Taste Bud ◽  
Lingual Epithelium ◽  
Processing Enzymes ◽  
Taste Cells ◽  
Specific Proteins ◽  
Fluorescence Protein ◽  
Taste Bud Cells

Abstract We and others have reported that taste cells in taste buds express many peptides in common with cells in the gut and islets of Langerhans in the pancreas. Islets and taste bud cells express the hormones glucagon and ghrelin, the same ATP-sensitive potassium channel responsible for depolarizing the insulin-secreting β cell during glucose-induced insulin secretion, as well as the propeptide-processing enzymes PC1/3 and PC2. Given the common expression of functionally specific proteins in taste buds and islets, it is surprising that no one has investigated whether insulin is synthesized in taste bud cells. Using immunofluorescence, we demonstrated the presence of insulin in mouse, rat, and human taste bud cells. By detecting the postprocessing insulin molecule C-peptide and green fluorescence protein (GFP) in taste cells of both insulin 1-GFP and insulin 2-GFP mice and the presence of the mouse insulin transcript by in situ hybridization, we further proved that insulin is synthesized in individual taste buds and not taken up from the parenchyma. In addition to our cytology data, we measured the level of insulin transcript by quantitative RT-PCR in the anterior and posterior lingual epithelia. These analyses showed that insulin is translated in the circumvallate and foliate papillae in the posterior, but only insulin transcript was detected in the anterior fungiform papillae of the rodent tongue. Thus, some taste cells are insulin-synthesizing cells generated from a continually replenished source of precursor cells in the adult mammalian lingual epithelium.

scholarly journals Identification of electrophysiologically distinct cell subpopulations in Necturus taste buds.

1993 ◽  
Vol 102 (1) ◽  
pp. 143-170 ◽  
Author(s):  
A Bigiani ◽  
S D Roper
Keyword(s):  
Lucifer Yellow ◽  
Taste Buds ◽  
Taste Bud ◽  
Basal Cells ◽  
Patch Clamp Technique ◽  
Lingual Epithelium ◽  
Voltage Gated ◽  
Receptor Cells ◽  
Taste Cells ◽  
K Currents

We used the patch clamp technique to record from taste cells in thin transverse slices of lingual epithelium from Necturus maculosus. In this preparation, the epithelial polarity and the cellular organization of the taste buds, as well as the interrelationships among cells within the taste bud, were preserved. Whole-cell recording, combined with cell identification using Lucifer yellow, allowed us to identify distinct subpopulations of taste cells based on their electrophysiological properties. Receptor cells could be divided in two groups: one group was characterized by the presence of voltage-gated Na+, K+, and Ca2+ currents; the other group was characterized by the presence of K+ currents only. Therefore, receptor cells in the first group would be expected to be capable of generating action potentials, whereas receptor cells in the second group would not. Basal taste cells could also be divided into two different groups. Some basal cells possessed voltage-gated Na+, K+, and Ca2+ conductances, whereas other basal cells only had K+ conductance. In addition to single taste cells, we were able to identify electrically coupled taste cells. We monitored cell-cell coupling by measuring membrane capacitance and by observing Lucifer yellow dye coupling. Electrical coupling in pairs of dye-coupled taste receptor cells was strong, as indicated by experiments with the uncoupling agent 1-octanol. Electrically coupled receptor cells possessed voltage-gated currents, including Na+ and K+ currents. The electrophysiological differentiation among taste cells presumably is related to functional diversifications, such as different chemosensitivities.

Some Observations on Changes in Denervated Taste Buds of Circumvallate Papillae of Rabbits

1969 ◽  
Vol 27 ◽  
pp. 308-309
Author(s):  
Sunao Fujimoto ◽  
Raymond G. Murray ◽  
Assia Murray
Keyword(s):  
Taste Buds ◽  
Taste Bud ◽  
Cell Type ◽  
Dark Cells ◽  
Type Iii ◽  
Circumvallate Papillae ◽  
Taste Bud Cells ◽  
Light Cells

Taste bud cells in circumvallate papillae of rabbit have been classified into three groups: dark cells; light cells; and type III cells. Unilateral section of the 9th nerve distal to the petrosal ganglion was performed in 18 animals, and changes of each cell type in the denervated buds were observed from 6 hours to 10 days after the operation.Degeneration of nerves is evident at 12 hours (Fig. 1) and by 2 days, nerves are completely lacking in the buds. Invasion by leucocytes into the buds is remarkable from 6 to 12 hours but then decreases. Their extrusion through the pore is seen. Shrinkage and disturbance in arrangement of cells in the buds can be seen at 2 days. Degenerated buds consisting of a few irregular cells and remnants of degenerated cells are present at 4 days, but buds apparently normal except for the loss of nerve elements are still present at 6 days.

scholarly journals Jacalin and peanut agglutinin (PNA) bindings in the taste bud cells of the rat: New reliable markers for type IV cells of the rat taste buds

2005 ◽  
Vol 68 (4) ◽  
pp. 243-250 ◽  
Author(s):  
Ryo Taniguchi ◽  
Lei Shi ◽  
Masae Fujii ◽  
Katsura Ueda ◽  
Shiho Honma ◽  
...  
Keyword(s):  
Taste Buds ◽  
Taste Bud ◽  
Peanut Agglutinin ◽  
Type Iv ◽  
Taste Bud Cells

Embryonic taste buds develop in the absence of innervation

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1103-1111 ◽  
Author(s):  
L.A. Barlow ◽  
C.B. Chien ◽  
R.G. Northcutt
Keyword(s):  
Embryonic Development ◽  
Taste Receptor ◽  
Nerve Fibers ◽  
Taste Buds ◽  
Taste Bud ◽  
Taste Cells ◽  
Experimental Approaches ◽  
Well Differentiated ◽  
Serotonin Immunoreactivity

It has been hypothesized that taste buds are induced by contact with developing cranial nerve fibers late in embryonic development, since descriptive studies indicate that during embryonic development taste cell differentiation occurs concomitantly with or slightly following the advent of innervation. However, experimental evidence delineating the role of innervation in taste bud development is sparse and equivocal. Using two complementary experimental approaches, we demonstrate that taste cells differentiate fully in the complete absence of innervation. When the presumptive oropharyngeal region was taken from a donor axolotl embryo, prior to its innervation and development of taste buds, and grafted ectopically on to the trunk of a host embryo, the graft developed well-differentiated taste buds. Although grafts were invaded by branches of local spinal nerves, these neurites were rarely found near ectopic taste cells. When the oropharyngeal region was raised in culture, numerous taste buds were generated in the complete absence of neural elements. Taste buds in grafts and in explants were identical to those found in situ both in terms of their morphology and their expression of calretinin and serotonin immunoreactivity. Our findings indicate that innervation is not necessary for complete differentiation of taste receptor cells. We propose that taste buds are either induced in response to signals from other tissues, such as the neural crest, or arise independently through intrinsic patterning of the local epithelium.

A method for in-situ tight-seal recordings from single taste bud cells of mice

1998 ◽  
Vol 84 (1-2) ◽  
pp. 109-114 ◽  
Author(s):  
Hidemasa Furue ◽  
Kiyonori Yoshii
Keyword(s):  
Taste Bud ◽  
Taste Bud Cells

scholarly journals Fingerprinting taste buds: intermediate filaments and their implication for taste bud formation

2000 ◽  
Vol 355 (1401) ◽  
pp. 1233-1237 ◽  
Author(s):  
Martin Witt ◽  
Klaus Reutter ◽  
Donald Ganchrow ◽  
Judith R. Ganchrow
Keyword(s):  
Epithelial Cells ◽  
Intermediate Filaments ◽  
Taste Buds ◽  
Taste Bud ◽  
Intermediate Filament Protein ◽  
Cytokeratin 20 ◽  
Nerve Fibres ◽  
Vimentin Expression ◽  
Disc Cells ◽  
Taste Bud Cells

Intermediate filaments in taste organs of terrestrial (human and chick) as well as aquatic ( Xenopus laevis ) species were detected using immunohistochemistry and electron microscopy. During development, the potential importance of the interface between the taste bud primordium and non–gustatory, adjacent tissues is evidenced by the distinct immunoreactivity of a subpopulation of taste bud cells for cytokeratins and vimentin. In human foetuses, the selective molecular marker for taste bud primordia, cytokeratin 20, is not detectable prior to the ingrowth of nerve fibres into the epithelium, which supports the hypothesis that nerve fibres are necessary for initiating taste bud development. Another intermediate filament protein, vimentin, occurs in derivatives of mesoderm, but usually not in epithelium. In humans, vimentin immunoreactivity is expressed mainly in border (marginal) epithelial cells of taste bud primordia, while in chick, vimentin expression occurs in most taste bud cells, whereas non–gustatory epithelium is vimentin immunonegative. Our chick data suggest a relationship between the degree of vimentin expression and taste bud cell proliferation especially during the perihatching period. It is suggested that surrounding epithelial cells (human) and mesenchymal cells (chick) may be contributing sources of developing taste buds. The dense perinuclear network of intermediate filaments especially in dark (i.e. non–sensory) taste disc cells of Xenopus indicates that vimentin filaments also might be associated with cells of non–gustatory function. These results indicate that the mechanisms of taste bud differentiation from source tissues may differ among vertebrates of different taxa.

Mouse mandibular retromolar taste buds associated with a mucus salivary gland

2021 ◽  
Author(s):  
Quan T Nguyen ◽  
Grace E Beck Coburn ◽  
Amber Valentino ◽  
Bekir Karabucak ◽  
Marco Tizzano
Keyword(s):  
Salivary Gland ◽  
Fluorescent Protein ◽  
Minor Salivary Gland ◽  
Immunohistochemical Analysis ◽  
Taste Buds ◽  
Taste Bud ◽  
Neuronal Marker ◽  
Taste Cells ◽  
Green Fluorescent ◽  
A Minor

Abstract We have characterized a recently rediscovered chemosensory structure at the rear of the mandibular mucosa in the mouse oral cavity originally reported in the 1980s. This consists of unorganized taste buds, not contained within troughs, associated with the ducts of an underlying minor salivary gland. Using whole-mount preparations of transgenic mice expressing green fluorescent protein under the promoter of taste-signaling-specific genes, we determined that the structure contains taste bud clusters and salivary gland orifices at the rear of each mandible, distal to the last molar and anterior to the ascending ramus. Immunohistochemical analysis show in the retromolar taste buds expression of the taste receptors Tas2R131 and T1R3 and taste cascade molecules TrpM5, PLCβ2, and GNAT3, consistent with type II taste cells, and expression of GAD1, consistent with type III taste cells. Furthermore, the neuronal marker CGRP in retromolar mucosa tissue wrapping around TrpM5+ taste buds was observed. RT-PCR showed that retromolar taste buds express all three mouse tas1r genes, 28 of the 35 tas2r genes, and taste transduction signaling genes gnat3, plcb2, and trpm5, making the retromolar TBs similar to other lingual and palate taste buds. Finally, histochemistry demonstrated that the mandibular retromolar secretory gland is a minor salivary gland of mucous type. The mandibular retromolar taste structure may thus play a role in taste sensation and represent a potential novel pharmacological target for taste disorders.

scholarly journals R-spondin substitutes for neuronal input for taste cell regeneration in adult mice

2020 ◽  
Vol 118 (2) ◽  
pp. e2001833118
Author(s):  
Xiaoli Lin ◽  
Chanyi Lu ◽  
Makoto Ohmoto ◽  
Katarzyna Choma ◽  
Robert F. Margolskee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
Taste Bud ◽  
Geniculate Ganglion ◽  
Systemic Delivery ◽  
E3 Ligases ◽  
Adult Mice ◽  
Taste Cells ◽  
Ganglion Neurons ◽  
Taste Bud Cells

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.

Scanning Electron Microscopy of the Taste Bud of the Mudpuppy, Necturus Maculosus

1975 ◽  
Vol 33 ◽  
pp. 530-531
Author(s):  
David W. Samanen ◽  
Rudy A. Bernard
Keyword(s):  
Taste Buds ◽  
Taste Bud ◽  
General Distribution ◽  
Surface Irregularity ◽  
Lingual Papillae ◽  
Necturus Maculosus ◽  
Neurophysiological Studies ◽  
Taste Bud Cells ◽  
Sectioned Tissue ◽  
Stimulation Of

The tongue of the mudpuppy, Necturus maculosus, appears smooth and without any papillae. Farbman and Yonkers (1971) reported that the tongue contains round elevations or eminences, each with a single, large taste bud. Furthermore, their light micrographs, made of sectioned tissue, showed that the tips of the buds are flush to the lingual surface. In contrast, the mammalian taste buds lie below the epithelium of the lingual papillae and contact the surface only by way of a narrow taste pore. We undertook SEM studies to confirm this morphology, one which would be advantageous for later neurophysiological studies involving the stimulation of individual taste buds and microelectrode recording from taste bud cells.Figure 1 shows two adjacent eminences from the mudpuppy's distal tongue. The taste bud shows as a surface irregularity, centered at the top of each mound. Their dimensions and general distribution correspond to those reported by Farbman and Yonkers.

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