Chemosensory Perception in the Gut

Höfer, Dirk; Asan, Esther; Drenckhahn, Detlev

doi:10.1152/physiologyonline.1999.14.1.18

Cited by 63 publications

(86 citation statements)

References 13 publications

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“…One of the specialized cell types in mammalian gastrointestinal mucosa, the brush cell (also known as tufted or caveolated cell), shares distinct features with the chemosensory taste receptor cells of the tongue. They both have an apical tuft of microvilli and express α-gustducin, the α subunit of the heterotrimeric cGMP-coupled protein involved in bitter transduction in oral taste receptor cells (Hofer et al, 1999;Rozengurt, 2006). Furthermore they all share the NTS as the first central relay and place of integration.…”

Section: Upper Small Intestine: Cck Gip and "Taste In The Gut"mentioning

confidence: 99%

The vagus nerve, food intake and obesity

Berthoud

2008

Regulatory Peptides

265

199

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Food interacts with sensors all along the alimentary canal to provide the brain with information regarding its composition, energy content, and beneficial effect. Vagal afferents innervating the gastrointestinal tract, pancreas, and liver provide a rapid and discrete account of digestible food in the alimentary canal, as well as circulating and stored fuels, while vagal efferents together with the sympathetic nervous system and hormonal mechanisms codetermine the rate of nutrient absorption, partitioning, storage, and mobilization. Although vagal sensory mechanisms play a crucial role in the neural mechanism of satiation, there is little evidence suggesting a significant role in long-term energy homeostasis. However, increasing recognition of vagal involvement in the putative mechanisms making bariatric surgeries the most effective treatment for obesity should greatly stimulate future research to uncover the many details regarding the specific transduction mechanisms in the periphery and the inter-and intra-neuronal signaling cascades disseminating vagal information across the neuraxis.

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Section: Upper Small Intestine: Cck Gip and "Taste In The Gut"mentioning

confidence: 99%

The vagus nerve, food intake and obesity

Berthoud

2008

Regulatory Peptides

265

199

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“…2E). These microvilli have also been reported to contain villin and fimbrin/plastin [49]. The function of solitary chemoreceptor cells has been examined in greatest detail for those in the nasal cavity, where they appear to respond to the inhalation of irritating substances by initiating protective reflexes, such as sneezing or apnea [47].…”

Section: Espins In the Microvillar Processes Of Other Sensory Cellsmentioning

confidence: 99%

Espins and the actin cytoskeleton of hair cell stereocilia and sensory cell microvilli

Sekerková

Zheng

Loomis

et al. 2006

Cell. Mol. Life Sci.

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The espins are novel actin-bundling proteins that are produced in multiple isoforms from a single gene. They are present at high concentration in the parallel actin bundle of hair cell stereocilia and are the target of deafness mutations in mice and humans. Espins are also enriched in the microvilli of taste receptor cells, solitary chemoreceptor cells, vomeronasal sensory neurons and Merkel cells, suggesting that espins play important roles in the microvillar projections of vertebrate sensory cells. Espins are potent actin-bundling proteins that are not inhibited by Ca 2+ . In cells, they efficiently elongate parallel actin bundles and, thereby, help determine the steady-state length of microvilli and stereocilia. Espins bind actin monomer via their WH2 domain and can assemble actin bundles in cells. Certain espin isoforms can also bind phosphatidylinositol 4,5-bisphosphate, profilins or SH3 proteins. These biological activities distinguish espins from other actin-bundling proteins and may make them well-suited to sensory cells. KeywordsEspin; actin; hair cell; stereocilia; microvilli; sensory; deafness; taste The stereocilia and microvilli of vertebrate sensory cells and their actinbundling proteinsMany classes of vertebrate sensory cells detect chemical or mechanical stimuli through microvilli or their derivatives, such as stereocilia. These relatively long-lived, fingerlike specializations of the plasma membrane are built around a common cytoskeletal element -the parallel actin bundle (PAB) [1]. PABs consist of tightly packed collections of actin filaments cross-linked by actin-bundling proteins. The filaments are aligned along their longitudinal axis and display a uniform polarity with respect to their preferred ends for actin monomer addition, which in microvilli and stereocilia is positioned at the distal tip. The PAB displays hallmarks of a supramolecular scaffold that determines the placement, dimensions, flexibility and signaling properties of microvilli and stereocilia. Although filopodia also contain a PAB at their core and are believed to sense the local environment, they are considerably more dynamic and differ significantly from microvilli and stereocilia in their molecular composition and biogenesis [2].

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“…Chemical and mechanical signals control motility, secretion and immune defenses in local and/or central neural and/or non-neural pathways (Buchan, 1999;Furness et al, 1999;Furness et al, 2004). It has been suggested that nutrients in the lumen evoke cholecystokinin (CCK), serotonin and ATP release from enteroendocrine and enterochromaffin cells located in epithelia, and these substances act as sensory mediators for sensory neurons (Eastwood et al, 1998;Buchan, 1999;Höfer et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Characteristics of subepithelial fibroblasts as a mechano-sensor in the intestine: cell-shape-dependent ATP release and P2Y1 signaling

Furuya

Sokabe

Furuya

2005

Journal of Cell Science

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Subepithelial fibroblasts form a cellular network just under the epithelium of the gastrointestinal tract. Using primary cultured cells isolated from rat duodenal villi, we previously found that subepithelial fibroblasts reversibly changed cell morphology between flat and stellate-shape depending on intracellular cAMP levels. In this paper, we examined cell-cell communication via released ATP and Ca2+ signaling in the cellular network. Subepithelial fibroblasts were sensitive to mechanical stress such as `touching' a cell with a fine glass rod and `stretching' cells cultured on elastic silicone chamber. Mechanical stimulations evoked Ca2+-increase in the cells and ATP-release from the cells. The released ATP activated P2Y receptors on the surrounding cells and propagated Ca2+-waves through the network. Concomitant with Ca2+-waves, a transient contraction of the network was observed. Histochemical, RT-PCR, western blotting and Ca2+ response analyses indicated P2Y1 is a dominant functional subtype. ATP-release and Ca2+ signaling were cell-shape dependent, i.e. they were abolished in stellate-shaped cells treated with dBcAMP, and recovered or further enhanced in re-flattened cells treated with endothelin. The response to ATP also decreased in stellate-shaped cells. These findings indicate cAMP-mediated intracellular signaling causes cell-shape change, which accompanies the changes in mechano- and ATP sensitivities. Using a co-culture system of neuronal cells (NG108-15) with subepithelial fibroblasts, we confirmed that mechanically induced Ca2+-waves propagated to neurons. From these findings we propose that subepithelial fibroblasts work as a mechanosensor in the intestine. Uptake of food, water and nutrients may cause mechanical stress on subepithelial fibroblasts in the villi. The ATP released by mechanical stimulation elicits Ca2+-wave propagation through the network via P2Y1 activation and also activates P2X on terminals of mucosal sensory neurons to regulate peristaltic motility.

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Chemosensory Perception in the Gut

Cited by 63 publications

References 13 publications

The vagus nerve, food intake and obesity

The vagus nerve, food intake and obesity

Espins and the actin cytoskeleton of hair cell stereocilia and sensory cell microvilli

Characteristics of subepithelial fibroblasts as a mechano-sensor in the intestine: cell-shape-dependent ATP release and P2Y1 signaling

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