Meng Michelle Y, Paine Luke W, Sagnat David, Bello Ivana, Oldroyd Sophie, Javid Farideh, Harper Matthew T, Hockley James R F, St John Smith Ewan, Owens Róisín M, Alric Laurent, Buscail Etienne, Welsh Fraser, Vergnolle Nathalie, Bulmer David C
Department of Pharmacology, University of Cambridge, Cambridge, UK.
IRSD, Université de Toulouse, INSERM, INRAE, ENVT, Université Toulouse III-Paul Sabatier (UPS), Toulouse, France.
Br J Pharmacol. 2025 Mar;182(6):1324-1340. doi: 10.1111/bph.17408. Epub 2024 Dec 3.
Abdominal pain is a leading cause of morbidity for people living with gastrointestinal disease. Whereas the transient receptor potential vanilloid 4 (TRPV4) ion channel has been implicated in the pathogenesis of abdominal pain, the relative paucity of TRPV4 expression in colon-projecting sensory neurons suggests that non-neuronal cells may contribute to TRPV4-mediated nociceptor stimulation.
Changes in murine colonic afferent activity were examined using ex vivo electrophysiology in tissues with the gut mucosa present or removed. ATP and glutamate release were measured by bioluminescence assays from human colon organoid cultures and mouse colon. Dorsal root ganglion sensory neuron activity was evaluated by Ca imaging when cultured alone or co-cultured with colonic mucosa.
Bath application of TRPV4 agonist GSK1016790A elicited a robust increase in murine colonic afferent activity, which was abolished by removing the gut mucosa. GSK1016790A promoted ATP and glutamate release from human colon organoid cultures and mouse colon. Inhibition of ATP degradation in mouse colon enhanced the afferent response to GSK1016790A. Pretreatment with purinoceptor or glutamate receptor antagonists attenuated and abolished the response to GSK1016790A when given alone or in combination, respectively. Sensory neurons co-cultured with colonic mucosal cells produced a marked increase in intracellular Ca to GSK1016790A compared with neurons cultured alone.
Our data indicate that mucosal release of ATP and glutamate is responsible for the stimulation of colonic afferents following TRPV4 activation. These findings highlight an opportunity to target the gut mucosa for the development of new visceral analgesics.
腹痛是胃肠道疾病患者发病的主要原因。虽然瞬时受体电位香草酸受体4（TRPV4）离子通道与腹痛的发病机制有关，但在投射至结肠的感觉神经元中TRPV4表达相对较少，这表明非神经元细胞可能参与了TRPV4介导的伤害感受器刺激。
使用离体电生理学方法，在保留或去除肠黏膜的组织中检测小鼠结肠传入神经活动的变化。通过生物发光测定法测量人结肠类器官培养物和小鼠结肠中ATP和谷氨酸的释放。当背根神经节感觉神经元单独培养或与结肠黏膜共培养时，通过钙成像评估其活性。
浴用TRPV4激动剂GSK1016790A可引起小鼠结肠传入神经活动显著增加，去除肠黏膜后该反应消失。GSK1016790A可促进人结肠类器官培养物和小鼠结肠中ATP和谷氨酸的释放。抑制小鼠结肠中ATP的降解可增强对GSK1016790A的传入反应。单独给予嘌呤受体拮抗剂或谷氨酸受体拮抗剂预处理可减弱和消除对GSK1016790A的反应，联合使用时效果更明显。与单独培养的神经元相比，与结肠黏膜细胞共培养的感觉神经元对GSK1016790A产生的细胞内钙显著增加。
我们的数据表明，TRPV4激活后，黏膜释放的ATP和谷氨酸可刺激结肠传入神经。这些发现凸显了以肠黏膜为靶点开发新型内脏镇痛药的机会。
