MOLECULAR CONTROL OF GLUCOSE METABOLISM

葡萄糖代谢的分子控制

• 批准号: 7357881
• 负责人: KOSAKU UYEDA
• 金额: $ 1.17万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7357881
• 关键词: Krebs' cycle; enzyme activity; enzymes; glucose metabolism; lactates; liver; oxidation; pyruvates

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this collaboration is (a) to determine the biochemical mechanism for the reduced REDOX state of liver of ChREBP-/-, and (b) to determine the source of pyruvate in the liver of ChREBP-/- mice fed high starch diet. We determined enzyme mRNA levels and enzyme activities of the Krebs cycle, electron shuttle enzymes and metabolite concentrations in the freeze-clamped liver of ChREBP-/- mice, isolated mitochondria and hepatocytes. A limitation of this approach is that changes in enzyme expression often do not match changes in flux. Because NMR isotopomer analysis is an excellent method for measuring fluxes in intact tissue, we took this approach to investigate the metabolism of hepatic pyruvate and lactate in ChREBP-/- mice. Substrate preference experiments were performed by perfusing isolated perfused livers with a mixture 13C labeled FFA, glucose, lactate and pyruvate. Preliminary results from this experiment indicate that FFA oxidation in the TCA cycle is reduced by half, from 80% in WT to 40% in the ChREBP -/-. Concordantly, pyruvate and lactate oxidation were higher in the ChREBP -/- mice compared to controls, in agreement with a 74% reduction in liver PDK3 enzyme activity.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。这项合作的目的是（a）确定ChREBP-/-肝脏REDOX状态降低的生化机制，以及（B）确定喂食高淀粉饮食的ChREBP-/-小鼠肝脏中丙酮酸的来源。我们确定了酶的mRNA水平和酶活性的克雷布斯循环，电子穿梭酶和代谢物浓度的ChREBP-/-小鼠，分离的线粒体和肝细胞的冷冻夹持的肝脏。这种方法的局限性在于酶表达的变化通常与通量的变化不匹配。由于NMR同位素分析是测量完整组织中通量的一种很好的方法，因此我们采用这种方法来研究ChREBP-/-小鼠肝脏丙酮酸和乳酸的代谢。通过用13 C标记的FFA、葡萄糖、乳酸盐和丙酮酸盐的混合物灌注分离的灌注肝脏进行底物偏好实验。该实验的初步结果表明，TCA循环中的FFA氧化减少了一半，从WT中的80%减少到ChREBP -/-中的40%。一致地，与对照组相比，ChREBP -/-小鼠中的丙酮酸和乳酸氧化更高，与肝脏PDK 3酶活性降低74%一致。