PDF(Pubmed)
Abstract：
OBJECTIVE: Growth differentiation factor 15 (GDF15), a stress related cytokine, was recently identified as a novel satiety signal acting via the GFRAL receptor located in the hindbrain. Bitter compounds are known to induce satiety via the release of glucagon-like peptide 1 (GLP-1) through activation of bitter taste receptors (TAS2Rs, 25 subtypes) on enteroendocrine cells in the gut. This study aimed to investigate whether and how bitter compounds induce a stress response in intestinal epithelial cells to affect GDF15 expression in patients with obesity, thereby facilitating satiety signaling from the gut.
METHODS: The acute effect of oral intake of the bitter-containing medication Plaquenil (hydroxychloroquine sulfate) on plasma GDF15 levels was evaluated in a placebo-controlled, double-blind, randomized, two-visit crossover study in healthy volunteers. Primary crypts isolated from the jejunal mucosa from patients with obesity were stimulated with vehicle or bitter compounds, and the effect on GDF15 expression was evaluated using RT-qPCR or ELISA. Immunofluorescence colocalization studies were performed between GDF15, epithelial cell type markers and TAS2Rs. The role of TAS2Rs was tested by 1) pretreatment with a TAS2R antagonist, GIV3727; 2) determining TAS2R4/43 polymorphisms that affect taste sensitivity to TAS2R4/43 agonists.
RESULTS: Acute intake of hydroxychloroquine sulfate increased GDF15 plasma levels, which correlated with reduced hunger scores and plasma ghrelin levels in healthy volunteers. This effect was mimicked in primary jejunal cultures from patients with obesity. GDF15 was expressed in enteroendocrine and goblet cells with higher expression levels in patients with obesity. Various bitter-tasting compounds (medicinal, plant extracts, bacterial) either increased or decreased GDF15 expression, with some also affecting GLP-1. The effect was mediated by specific intestinal TAS2R subtypes and the unfolded protein response pathway. The bitter-induced effect on GDF15/GLP-1 expression was influenced by the existence of TAS2R4 amino acid polymorphisms and TAS2R43 deletion polymorphisms that may predict patient\'s therapeutic responsiveness. However, the effect of the bitter-tasting antibiotic azithromycin on GDF15 release was mediated via the motilin receptor, possibly explaining some of its aversive side effects.
CONCLUSIONS: Bitter chemosensory and pharmacological receptors regulate the release of GDF15 from human gut epithelial cells and represent potential targets for modulating metabolic disorders or cachexia.
METHODS: The acute effect of oral intake of the bitter-containing medication Plaquenil (hydroxychloroquine sulfate) on plasma GDF15 levels was evaluated in a placebo-controlled, double-blind, randomized, two-visit crossover study in healthy volunteers. Primary crypts isolated from the jejunal mucosa from patients with obesity were stimulated with vehicle or bitter compounds, and the effect on GDF15 expression was evaluated using RT-qPCR or ELISA. Immunofluorescence colocalization studies were performed between GDF15, epithelial cell type markers and TAS2Rs. The role of TAS2Rs was tested by 1) pretreatment with a TAS2R antagonist, GIV3727; 2) determining TAS2R4/43 polymorphisms that affect taste sensitivity to TAS2R4/43 agonists.
RESULTS: Acute intake of hydroxychloroquine sulfate increased GDF15 plasma levels, which correlated with reduced hunger scores and plasma ghrelin levels in healthy volunteers. This effect was mimicked in primary jejunal cultures from patients with obesity. GDF15 was expressed in enteroendocrine and goblet cells with higher expression levels in patients with obesity. Various bitter-tasting compounds (medicinal, plant extracts, bacterial) either increased or decreased GDF15 expression, with some also affecting GLP-1. The effect was mediated by specific intestinal TAS2R subtypes and the unfolded protein response pathway. The bitter-induced effect on GDF15/GLP-1 expression was influenced by the existence of TAS2R4 amino acid polymorphisms and TAS2R43 deletion polymorphisms that may predict patient\'s therapeutic responsiveness. However, the effect of the bitter-tasting antibiotic azithromycin on GDF15 release was mediated via the motilin receptor, possibly explaining some of its aversive side effects.
CONCLUSIONS: Bitter chemosensory and pharmacological receptors regulate the release of GDF15 from human gut epithelial cells and represent potential targets for modulating metabolic disorders or cachexia.
摘要：
目标：生长分化因子15（GDF15），应激相关的细胞因子，最近被确定为通过位于后脑的GFRAL受体起作用的新型饱腹感信号。已知苦味化合物通过激活苦味受体（TAS2R，25种亚型）在肠道中的肠内分泌细胞上。这项研究旨在探讨苦味化合物是否以及如何诱导肠上皮细胞的应激反应以影响肥胖患者的GDF15表达。从而促进来自肠道的饱腹感信号。
方法：在安慰剂对照中评估口服含苦味药物Plaquenil（硫酸羟氯喹）对血浆GDF15水平的急性影响，双盲,随机化，在健康志愿者中进行两次访问交叉研究。用媒介物或苦味化合物刺激从肥胖患者的空肠粘膜分离的原发性隐窝，并使用RT-qPCR或ELISA评估对GDF15表达的影响。在GDF15、上皮细胞类型标志物和TAS2R之间进行免疫荧光共定位研究。通过1）用TAS2R拮抗剂预处理来测试TAS2R的作用，GIV3727;2)确定影响对TAS2R4/43激动剂的味觉敏感性的TAS2R4/43多态性。
结果：急性摄入硫酸羟氯喹增加GDF15血浆水平，这与健康志愿者的饥饿评分和血浆ghrelin水平降低有关。在肥胖患者的原发性空肠培养物中模仿了这种作用。肥胖患者GDF15在肠内分泌和杯状细胞中表达，表达水平较高。各种苦味化合物(药用，植物提取物,细菌)增加或减少GDF15表达，一些也影响GLP-1。该效应是由特定的肠道TAS2R亚型和未折叠的蛋白应答途径介导的。苦味对GDF15/GLP-1表达的诱导作用受TAS2R4氨基酸多态性和TAS2R43缺失多态性的存在影响，这些多态性可以预测患者的治疗反应性。然而,苦味抗生素阿奇霉素对GDF15释放的影响是通过胃动素受体介导的，可能解释了它的一些令人厌恶的副作用。
结论：苦味化学和药理受体调节人肠道上皮细胞释放GDF15，并代表调节代谢紊乱或恶病质的潜在靶点。
方法：在安慰剂对照中评估口服含苦味药物Plaquenil（硫酸羟氯喹）对血浆GDF15水平的急性影响，双盲,随机化，在健康志愿者中进行两次访问交叉研究。用媒介物或苦味化合物刺激从肥胖患者的空肠粘膜分离的原发性隐窝，并使用RT-qPCR或ELISA评估对GDF15表达的影响。在GDF15、上皮细胞类型标志物和TAS2R之间进行免疫荧光共定位研究。通过1）用TAS2R拮抗剂预处理来测试TAS2R的作用，GIV3727;2)确定影响对TAS2R4/43激动剂的味觉敏感性的TAS2R4/43多态性。
结果：急性摄入硫酸羟氯喹增加GDF15血浆水平，这与健康志愿者的饥饿评分和血浆ghrelin水平降低有关。在肥胖患者的原发性空肠培养物中模仿了这种作用。肥胖患者GDF15在肠内分泌和杯状细胞中表达，表达水平较高。各种苦味化合物(药用，植物提取物,细菌)增加或减少GDF15表达，一些也影响GLP-1。该效应是由特定的肠道TAS2R亚型和未折叠的蛋白应答途径介导的。苦味对GDF15/GLP-1表达的诱导作用受TAS2R4氨基酸多态性和TAS2R43缺失多态性的存在影响，这些多态性可以预测患者的治疗反应性。然而,苦味抗生素阿奇霉素对GDF15释放的影响是通过胃动素受体介导的，可能解释了它的一些令人厌恶的副作用。
结论：苦味化学和药理受体调节人肠道上皮细胞释放GDF15，并代表调节代谢紊乱或恶病质的潜在靶点。
