Search results for "Nutrient sensing"
showing 9 items of 9 documents
Direct Sensing of Nutrients via a LAT1-like Transporter in Drosophila Insulin-Producing Cells
2016
Summary Dietary leucine has been suspected to play an important role in insulin release, a hormone that controls satiety and metabolism. The mechanism by which insulin-producing cells (IPCs) sense leucine and regulate insulin secretion is still poorly understood. In Drosophila, insulin-like peptides (DILP2 and DILP5) are produced by brain IPCs and are released in the hemolymph after leucine ingestion. Using Ca2+-imaging and ex vivo cultured larval brains, we demonstrate that IPCs can directly sense extracellular leucine levels via minidiscs (MND), a leucine transporter. MND knockdown in IPCs abolished leucine-dependent changes, including loss of DILP2 and DILP5 in IPC bodies, consistent wit…
Novel molecular mechanisms for the adaptogenic effects of herbal extracts on isolated brain cells using systems biology.
2018
Abstract Introduction Adaptogens are natural compounds or plant extracts that increase adaptability and survival of organisms under stress. Adaptogens stimulate cellular and organismal defense systems by activating intracellular and extracellular signaling pathways and expression of stress-activated proteins and neuropeptides. The effects adaptogens on mediators of adaptive stress response and longevity signaling pathways have been reported, but their stress-protective mechanisms are still not fully understood. Aim of the study The aim of this study was to identify key molecular mechanisms of adaptogenic plants traditionally used to treat stress and aging-related disorders, i.e., Rhodiola r…
Nutrient sensing pathways as therapeutic targets for healthy ageing
2017
Introduction: In the present paper, the authors have discussed anti-aging strategies which aim to slow the aging process and to delay the onset of age-related diseases, focusing on nutrient sensing pathways (NSPs) as therapeutic targets. Indeed, several studies have already demonstrated that both in animal models and humans, dietary interventions might have a positive impact on the aging process through the modulation of these pathways. Areas covered: Achieving healthy aging is the main challenge of the twenty-first century because lifespan is increasing, but not in tandem with good health. The authors have illustrated different approaches that can act on NSPs, modulating the rate of the ag…
2016
AbstractGenetic manipulations in nutrient-sensing pathways are known to both extend lifespan and modify responses to environmental stressors (e.g., starvation, oxidative and thermal stresses), suggesting that similar mechanisms regulate lifespan and stress resistance. However, despite being a key factor reducing female lifespan and affecting female fitness, male-induced harm has rarely been considered as a stressor mediated by nutrient sensing pathways. We explored whether a lifespan-extending manipulation also modifies female resistance to male-induced harm. To do so, we used long-lived female Drosophila melanogaster that had their insulin signalling pathway downregulated by genetically ab…
Frontiers in Physiology
2021
Besides its roles in locomotion and thermogenesis, skeletal muscle plays a significant role in global glucose metabolism and insulin sensitivity through complex nutrient sensing networks. Our previous work showed that the muscle-specific ablation of O-GlcNAc transferase (OGT) led to a lean phenotype through enhanced interleukin-15 (IL-15) expression. We also showed OGT epigenetically modified and repressed the Il15 promoter. However, whether there is a causal relationship between OGT ablation-induced IL-15 secretion and the lean phenotype remains unknown. To address this question, we generated muscle specific OGT and interleukin-15 receptor alpha subunit (IL-15rα) double knockout mice (mDKO…
Glucose and hypothalamic astrocytes: More than a fueling role?
2015
Brain plays a central role in energy homeostasis continuously integrating numerous peripheral signals such as circulating nutrients, and in particular blood glucose level, a variable that must be highly regulated. Then, the brain orchestrates adaptive responses to modulate food intake and peripheral organs activity in order to achieve the fine tuning of glycemia. More than fifty years ago, the presence of glucose-sensitive neurons was discovered in the hypothalamus, but what makes them specific and identifiable still remains disconnected from their electrophysiological signature. On the other hand, astrocytes represent the major class of macroglial cells and are now recognized to support an…
Chemosensory signalling pathways involved in sensing of amino acids by the ghrelin cell
2015
AbstractTaste receptors on enteroendocrine cells sense nutrients and transmit signals that control gut hormone release. This study aimed to investigate the amino acid (AA) sensing mechanisms of the ghrelin cell in a gastric ghrelinoma cell line, tissue segments and mice. Peptone and specific classes of amino acids stimulate ghrelin secretion in the ghrelinoma cell line. Sensing of L-Phe occurs via the CaSR, monosodium glutamate via the TAS1R1-TAS1R3 while L-Ala and peptone act via 2 different amino acid taste receptors: CaSR & TAS1R1-TAS1R3 and CaSR & GPRC6A, respectively. The stimulatory effect of peptone on ghrelin release was mimicked ex vivo in gastric but not in jejunal tissue …
Nutrient sensing: What can we learn from different tastes about the nutrient contents in today's foods?
2019
Abstract Tastes are often described as having a nutrient-signaling function eliciting expectations about the food and its nutrient content. The objectives of this work was to investigate correlations between taste intensity and nutrient content, to evaluate the impact of competing tastes on these relationships, and to know if the content in certain nutrients could be inferred from a combination of tastes. The Food Taste Database (Martin et al., 2014) and a French Food Composition table (ANSES-Ciqual) were used to obtain a dataset combining sensory and nutritional information for 365 foods. Our results confirm the existence of several taste-nutrient relationships previously suggested by othe…