Affiliation:
1. Institute for Anatomy and Cell Biology Justus‐Liebig‐University Giessen 35385 Giessen Germany
2. Leibniz Institute on Aging–Fritz Lipmann Institute 07745 Jena Germany
3. Division of Allergy and Clinical Immunology Brigham and Women's Hospital and Department of Medicine Harvard Medical School Boston MA 02115 USA
4. Centre des Sciences du Goût et de l'Alimentation CNRS INRAE Institut Agro Université de Bourgogne Dijon F‐21000 France
Abstract
AbstractIncreased sugar concentrations on mucosal surfaces display risk factors for infections. This study aims to clarify sugar monitoring in the urethra. Urethral tuft cells (UTC) are known sentinels monitoring the urethral lumen for potentially harmful substances and initiating protective mechanisms. Next‐generation sequencing (NGS), RT‐PCR, and immunohistochemistry show expression of the taste receptor Tas1R3 in murine UTC, a crucial component of the classical sweet detection pathway. Isolated UTC respond to various sugars with an increase of intracellular [Ca2+]. The Tas1R3 inhibitor gurmarin and Tas1R3 deletion reduces these responses. Utilizing mice lacking UTC, glibenclamide, a K+‐ATP channel antagonist, and phlorizin, a SGLT1 inhibitor, reveal an additional Tas1R3 independent sweet detection pathway. Inhibition of both pathways abrogates the sugar responses. Rat cystometry shows that intraurethral application of sucrose and glucose increases detrusor muscle activity Tas1R3 dependently. Sugar monitoring in the urethra occurs via two distinct pathways. A Tas1R3 dependent pathway, exclusive to UTC, and a Tas1R3 independent sweet detection pathway, which can be found both in UTC and in other urethral epithelial cells.
Funder
Else Kröner-Fresenius-Stiftung
Uniklinikum Giessen und Marburg