Sensing and signaling of protein-derived nutrients in the gastointestinal tract

监测胃肠道中摄入的宏量营养素的数量和组成对于引起适当的生理反应至关重要，特别是在食物摄入和食物选择的背景下。先前的研究表明，膳食蛋白质对饱腹感有特别有效的影响。胃肠道不同区室中的细胞如何感知膳食蛋白质或其消化产物尚不清楚。因此，本研究旨在鉴定化学感受细胞，并探讨化学感觉信息转化为内分泌或神经元信号的机制。假定的感觉细胞将根据氨基酸候选受体的存在及其对适当营养物质的反应来确定。胃肠道化学感觉细胞可能是像味觉系统那样将化学感觉信息传递给邻近效应细胞的特化感知细胞，也可能是具有化学感觉信号元件的内分泌细胞。这个项目的结果将有助于更好地理解胃肠道过程和大脑中饥饿/饱腹感中心之间的相互作用。

Monitoring the amount and composition of ingested macronutrients in the gastrointestinal tract is of vital importance to elicit appropriate physiological responses, especially in the context of food intake and food choice. Previous studies indicate that dietary protein has a particularly effective influence on satiety. How cells in the different compartments of the gastrointestinal tract sense dietary protein or its digestive products is unknown. Therefore, the proposed study is aimed to identify the chemoreceptive cells and to explore the mechanisms how the chemosensory information is transformed into endocrine or neuronal signals. Putative sensory cells will be identified based on the presence of candidate receptors for amino acids and their responsiveness to suitable nutrients. Gastrointestinal chemosensory cells could either be specialized sensing cells which convey chemosensory information to neighboring effector cells as proposed for the gustatory system, or they could be endocrine cells equipped with chemosensory signaling elements. The results of this project will contribute to a better understanding of the interplay between gastrointestinal processes and the hunger/satiety centers in the brain.