Band-like arrangement of taste-like sensory cells at the gastric groove: evidence for paracrine communication

Abstract

The discovery of taste-related elements within the gastrointestinal tract has led to a growing interest in the mechanisms and physiological significance of chemosensory monitoring of chymus composition. Previous work suggests that brush cells located in the “gastric groove,” which parallels the “limiting ridge,” a structure in rodents that divides the fundus from the corpus, are candidate sensory cells. A novel sectioning technique revealed that these cells are arranged in a palisade-like manner forming a band which borders the whole length of the corpus epithelium. Using transgenic PLCβ2 promoter-GFP mice and specific antibodies, we have demonstrated that most of these cells express gustducin, PLCβ2, and TRPM5; typical signaling proteins of gustatory sensory “type II” cells. These molecular features strongly suggest that the cells may be capable of sensing nutrient or non-nutrient constituents of the ingested food. Since there is no evidence that brush cells are endocrine cells, attempts were made to explore how such putative chemosensory cells might transmit the information to “effector” cells. It was found that most of the cells express the neuronal nitric oxide synthase (NOS) suggesting some paracrine interaction with adjacent cells. Moreover, they also express choline acetyltransferase (ChAT) as well as the vesicular protein SNAP25, indicating the potential for cholinergic transmission, possibly with subjacent enteric nerve fibers.

Unique Cellular Lineage Composition of the First Gland of the Mouse Gastric Corpus

“…As previously reported, the first gland contains an unusually large number of tuft or brush chemosensory cells. 1,2,21,48,49 In addition, the first gland cells prominently expressed Clusterin. Clusterin is considered a stress response protein and has been associated with metaplastic lineages in the stomach such as SPEM.…”

“…In rodents, this transition has been defined anatomically as the "limiting ridge" or the "gastric groove." 1,2 The formation of these different epithelial zones is determined during development. Previous investigations have implicated a loss of Sox2 in patterning the transition between squamous and glandular mucosa between the forestomach and the glandular stomach.…”

Transient Receptor Potential Channels as Drug Targets: From the Science of Basic Research to the Art of Medicine

“…Some TRPM5-containing taste receptor cells are coupled (as in the gastric groove) to neuronal nitric-oxide synthase (nNOS), suggesting paracrine interactions (Eberle et al, 2013). TRPM5 in taste receptor cells of the tongue is important for the transduction of sweet, amino acid, and bitter stimuli that bind to GPCRs that are coupled to PLCb.…”

Taste Receptor Gene Expression Outside the Gustatory System

“…Single PLCβ2-positive cells in the small intestine and in colonic mucosa were demonstrated in rodent [2,19,122] and human tissue samples [11]. In the stomach, PLCβ2-expressing cells are found in separated populations in two distinct anatomical and functional regions of the organ, the corpus mucosa and the limiting ridge [112,124].…”