Intracellular zinc-dependent TAS2R8 gene expression through CTCF activation

Lipopolysaccharide increases bitter taste sensitivity via epigenetic changes in Tas2r gene clusters

T2R bitter receptors, encoded by Tas2r genes, are not only critical for bitter taste signal transduction but also important for defense against bacteria and parasites. However, little is known about whether and how Tas2r gene expression are regulated. Here, we show that in an inflammation model mimicking bacterial infection using lipopolysaccharide, the expression of many Tas2rs was significantly upregulated and mice displayed markedly increased neural and behavioral responses to bitter compounds. Using single-cell assays for transposase-accessible chromatin with sequencing (scATAC-seq), we found that the chromatin accessibility of Tas2rs was highly celltype specific and lipopolysaccharide increased the accessibility of many Tas2rs. scATAC-seq also revealed substantial chromatin remodeling in immune response genes in taste tissue stem cells, suggesting potential long-lasting effects. Together, our results suggest an epigenetic mechanism connecting inflammation, Tas2r gene regulation, and altered bitter taste, which may explain heightened bitter taste that can occur with infections and cancer treatments.

Inflammation induces bitter taste oversensitization via epigenetic changes in Tas2r gene clusters

T2R bitter receptors, encoded by Tas2r genes, are not only critical for bitter taste signal transduction but also important for defense against bacteria and parasites. However, little is known about whether and how Tas2r gene expression are regulated. Here we show that, in an inflammation model mimicking bacterial infection, the expression of many Tas2rs are significantly up-regulated and mice displayed markedly increased neural and behavioral responses to bitter compounds. Using single-cell assays for transposase-accessible chromatin with sequencing (scATAC-seq), we found that the chromatin accessibility of Tas2rs was highly cell type specific and inflammation increased the accessibility of many Tas2rs . scATAC-seq also revealed substantial chromatin remodeling in immune response genes in taste tissue stem cells, suggesting potential long-term effects. Together, our results suggest an epigenetic mechanism connecting inflammation, Tas2r gene regulation, and altered bitter taste, which may explain heightened bitter taste that can occur with infections and cancer treatments.

Association of TRPM5 Asn235Ser Polymorphism and Trace Elements/Minerals in Chronic Gastritis Patients: a Case-Control Study

The link between chronic gastritis and chemosensory receptors is considered promising for disease prediction and treatment. The transient receptor potential melastatin member channel 5 (TRPM5) is an ion channel and may be a chemosensor in the gastrointestinal tract. Trace elements and minerals involved in many protein structures can change ion channel activity. Our study aimed to determine trace element and mineral levels according to TRPM5 Asn235Ser missense polymorphism distributions in patients with H. pylori (+) and (-) gastritis and to uncover their possible association with disease pathogenesis. In 109 volunteer patients diagnosed with gastritis [64 H. pylori (+), 45 H. pylori (-)], TRPM5 (Asn235Ser) polymorphism was detected by Kompetitive Allele-Specific PCR method (KASP), but no difference was found between the groups. There are differences between the serum trace element (Se, Zn, Cu, Mg, and Cu/Zn) levels of the two groups. High serum Se and Cu/Zn ratios were detected in H. pylori (+) patients. Cu/Zn ratio can be used as a marker of bacterial inflammation. The amount of Se was found to be statistically significant in the serums of H. pylori (+) patients carrying TT and CT genotype, while the amounts of Zn, Cu, and Mg were found as significant of H. pylori (-) patients. The relationship of Se with the H. pylori needs to be investigated further. In addition, H. pylori (+) patients have a significantly higher neutrophils/lymphocytes ratio (NLR) compared to those with H. pylori (-) NLR can be used as an indicator of inflammation.