Murine intestinal cells expressing Trpm5 are mostly brush cells and express markers of neuronal and inflammatory cells

Abstract

To determine the role in chemosensation of intestinal solitary cells that express taste receptors and Trpm5, we carried out a microarray study of the transcriptome of FACS-sorted transgenic mouse intestinal cells expressing enhanced green fluorescent protein (eGFP) under the control of the Trpm5 promoter and compared it with that of intestinal cells that do not express eGFP. The findings of the study are: 1) Morphology and expression of markers show that most eGFP+ cells are brush cells. 2) The majority of proteins known to be involved in taste signal transduction are expressed in the eGFP+ cells, although the isoforms are not always the same. 3) eGFP+ cells express pre- and postsynaptic markers and nerves are often found in close proximity. 4) Several genes that play a role in inflammation are expressed specifically in eGFP+ cells. Furthermore, these cells express the entire biosynthesis pathway of leucotriene C4, an eicosanoid involved in modulation of intestinal smooth muscle contraction. 5) Angiotensinogen, renin, and succinate receptor genes are expressed in the eGFP+ cells, suggesting a role in the regulation of water and sodium transport, vasomotricity, and blood pressure. These data suggest that the Trpm5-expressing cells integrate many signals, including chemical signals from ingested food, and that they may regulate several physiological functions of the gastrointestinal tract.

A single-cell survey of the small intestinal epithelium

“…Recently, tuft cells were also shown to play a key role in the T helper 2 (Th2) response to Helminth infection, through Interleukin-25 ( Il25 ) 2,15,32 . A previous tuft cell signature 33 based on bulk profiles of Trpm5 + tuft cells contained both neuronal and inflammation gene programs; this could reflect either co-expression in the same cells or distinct subsets.…”

“…7d). Thus, the inflammation and neuronal genes in the bulk signatures 33 likely belonged to distinct cells.…”

TRP channels in neurogastroenterology: opportunities for therapeutic intervention

“…However, important species differences do exist as in the murine gut TRPM5 is not colocalized with any of the classical markers for EEC cells such as chromogranin A, 5-HT, glucagon-like peptide 1, ghrelin and cholecystokinin (Bezencon et al, 2007;Kokrashvili et al, 2009). In mouse, TRPM5 is mostly expressed in brush cells (Kaske et al, 2007;Bezencon et al, 2008), also referred to as tufted or caveolated cells (Sbarbati and Osculati, 2005a,b;Morroni et al, 2007). Recently, it has been shown to be essential for the release of endogenous opioids from duodenal epithelial cells that contain enkaphelin and uroguanilyn (Kokrashvili et al, 2009).…”

Caffeine induces gastric acid secretion via bitter taste signaling in gastric parietal cells

“…Transducin, a similar G protein also present in taste cells, can replace the function of α-gustducin (25,26). TAS2R-expressing cells in the gastrointestinal tract have been reported to coexpress the downstream taste signaling components, suggesting that similar signal transduction pathways could also mediate gastrointestinal physiology (27). However, the detailed signal transduction pathways in extraoral chemosensitive cells are yet unknown.…”