Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC...Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.展开更多
CYP3A5 is a cytochrome P450(CYP)enzyme that metabolizes drugs and contributes to drug resistance in cancer.However,it remains unclear whether CYP3A5 directly influences cancer progression.In this report,we demonstrate...CYP3A5 is a cytochrome P450(CYP)enzyme that metabolizes drugs and contributes to drug resistance in cancer.However,it remains unclear whether CYP3A5 directly influences cancer progression.In this report,we demonstrate that CYP3A5 regulates glucose metabolism in pancreatic ductal adenocarcinoma.Multi-omics analysis showed that CYP3A5 knockdown re-sults in a decrease in various glucose-related metabolites through its effect on glucose trans-port.A mechanistic study revealed that CYP3A5 enriches the glucose transporter GLUT1 at the plasma membrane by restricting the translation of TXNIP,a negative regulator of GLUT1.Notably,CYP3A5-generated reactive oxygen species were proved to be responsible for atten-uating the AKT-4EBP1-TXNIP signaling pathway.CYP3A5 contributes to cell migration by maintaining high glucose uptake in pancreatic cancer.Taken together,our results,for the first time,reveal a role of CYP3A5 in glucose metabolism in pancreatic ductal adenocarcinoma and identify a novel mechanism that is a potential therapeutic target.展开更多
近年来,随着对肿瘤生物学研究的不断深入,人们对复杂的肿瘤代谢重编程更新、更全面的认识。葡萄糖转运蛋白1(glucose transport protein-1,GLUT-1)在不同肿瘤细胞的质膜上有不同程度的过度表达,过表达的GLUT-1会使肿瘤细胞摄入更多的葡...近年来,随着对肿瘤生物学研究的不断深入,人们对复杂的肿瘤代谢重编程更新、更全面的认识。葡萄糖转运蛋白1(glucose transport protein-1,GLUT-1)在不同肿瘤细胞的质膜上有不同程度的过度表达,过表达的GLUT-1会使肿瘤细胞摄入更多的葡萄糖以重编程细胞的代谢模式,。同时,对肿瘤微环境的改变有着重要的影响。并且,在肿瘤中GLUT-1的调节是近年来关注的重点,目前,已报道的上游调控因子主要有PTEN基因编码的蛋白质(phosphatase and tension homolog deleted on chromosome ten,PTEN)、缺氧诱导因子(hypoxia inducible factor,HIF),GLUT-1还会通过影响p53和细胞致瘤基因(cellular-myelocytomatosis viral oncogene,c-Myc)通路等在肿瘤的发生与发展中发挥着重要的作用。本文主要综述GLUT-1的结构与功能、在肿瘤代谢重编程中通过转运不同底物对肿瘤的影响、GLUT-1的调节和目前针对GLUT-1的治疗等。同时,阐述了GLUT-1与肿瘤代谢重编程的研究现状,分析了当前存在的问题,旨在为抗肿瘤机制研究以及恶性肿瘤靶向治疗研究提供参考。展开更多
Previous studies have shown two components of glucose absorption in the small intestine: a secondary active transport through SGLT1, and unsaturated component, recently attributed mainly to the facilitated diffusion t...Previous studies have shown two components of glucose absorption in the small intestine: a secondary active transport through SGLT1, and unsaturated component, recently attributed mainly to the facilitated diffusion through GLUT2, but the relationship between these two components under physiological conditions remains controversial. In chronic experiments on nonanesthetized rats we investigated for the first time the kinetics of maltose hydrolysis and glucose absorption in the isolated loop of the small intestine in a wide range of maltose and glucose concentrations (25 ÷ 200 mmol/l glucose). The processes were simulated on mathematical models which took into account the current views about mechanisms of hydrolysis and transport of nutrients and geometric characteristics of the intestinal surface. The results of chronic experiments and mathematical simulation have shown that under the close to physiological conditions the glucose transport mediated by SGLT1 is the main mechanism of its absorption in comparison with the unsaturated component. This was demonstrated not only at low, but also at high substrate concentrations. We conclude that correct evaluation of the relative contribution of different mechanisms in glucose transport through the intestinal epithelium requires taking into account the geometric specificities of its surface.展开更多
基金supported by the National Natural Science foundation of China(No.31071531)the Scientific Research Fund of the Hunan Provincial Education Department(No.14A071)the China National Tobacco Corp Hunan Branch(15-17Aa04)
文摘Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.
基金supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number R35GM118041.
文摘CYP3A5 is a cytochrome P450(CYP)enzyme that metabolizes drugs and contributes to drug resistance in cancer.However,it remains unclear whether CYP3A5 directly influences cancer progression.In this report,we demonstrate that CYP3A5 regulates glucose metabolism in pancreatic ductal adenocarcinoma.Multi-omics analysis showed that CYP3A5 knockdown re-sults in a decrease in various glucose-related metabolites through its effect on glucose trans-port.A mechanistic study revealed that CYP3A5 enriches the glucose transporter GLUT1 at the plasma membrane by restricting the translation of TXNIP,a negative regulator of GLUT1.Notably,CYP3A5-generated reactive oxygen species were proved to be responsible for atten-uating the AKT-4EBP1-TXNIP signaling pathway.CYP3A5 contributes to cell migration by maintaining high glucose uptake in pancreatic cancer.Taken together,our results,for the first time,reveal a role of CYP3A5 in glucose metabolism in pancreatic ductal adenocarcinoma and identify a novel mechanism that is a potential therapeutic target.
文摘近年来,随着对肿瘤生物学研究的不断深入,人们对复杂的肿瘤代谢重编程更新、更全面的认识。葡萄糖转运蛋白1(glucose transport protein-1,GLUT-1)在不同肿瘤细胞的质膜上有不同程度的过度表达,过表达的GLUT-1会使肿瘤细胞摄入更多的葡萄糖以重编程细胞的代谢模式,。同时,对肿瘤微环境的改变有着重要的影响。并且,在肿瘤中GLUT-1的调节是近年来关注的重点,目前,已报道的上游调控因子主要有PTEN基因编码的蛋白质(phosphatase and tension homolog deleted on chromosome ten,PTEN)、缺氧诱导因子(hypoxia inducible factor,HIF),GLUT-1还会通过影响p53和细胞致瘤基因(cellular-myelocytomatosis viral oncogene,c-Myc)通路等在肿瘤的发生与发展中发挥着重要的作用。本文主要综述GLUT-1的结构与功能、在肿瘤代谢重编程中通过转运不同底物对肿瘤的影响、GLUT-1的调节和目前针对GLUT-1的治疗等。同时,阐述了GLUT-1与肿瘤代谢重编程的研究现状,分析了当前存在的问题,旨在为抗肿瘤机制研究以及恶性肿瘤靶向治疗研究提供参考。
文摘Previous studies have shown two components of glucose absorption in the small intestine: a secondary active transport through SGLT1, and unsaturated component, recently attributed mainly to the facilitated diffusion through GLUT2, but the relationship between these two components under physiological conditions remains controversial. In chronic experiments on nonanesthetized rats we investigated for the first time the kinetics of maltose hydrolysis and glucose absorption in the isolated loop of the small intestine in a wide range of maltose and glucose concentrations (25 ÷ 200 mmol/l glucose). The processes were simulated on mathematical models which took into account the current views about mechanisms of hydrolysis and transport of nutrients and geometric characteristics of the intestinal surface. The results of chronic experiments and mathematical simulation have shown that under the close to physiological conditions the glucose transport mediated by SGLT1 is the main mechanism of its absorption in comparison with the unsaturated component. This was demonstrated not only at low, but also at high substrate concentrations. We conclude that correct evaluation of the relative contribution of different mechanisms in glucose transport through the intestinal epithelium requires taking into account the geometric specificities of its surface.
