Expression of GLUT-1 and GLUT-3 in Xanthogranulomatous Cholecystitis Induced a Positive Result on 18F-FDG PET: Report of a Case

Although several reports have revealed that fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) is useful for differentiating between benign and malignant lesions in the gallbladder, the positive results of ¹⁸F-FDG PET are not specific for malignancy because ¹⁸F-FDG is also accumulated in inflammatory lesions. It is known that the most important pathway for ¹⁸F-FDG to enter the cell body is mediated by the facilitative glucose transporter-1 (GLUT-1) through GLUT-3. We herein present a case of xanthogranulomatous cholecystitis (XGC) with a positive result on ¹⁸F-FDG PET. In this case, GLUT-1 and GLUT-3 were both positively expressed in inflammatory cells at the gallbladder wall of XGC and this is the first report to reveal GLUT expression in XGC. This report reveals that surgeons should carefully consider the appropriate treatment of gallbladder tumor, even with a positive result on ¹⁸F-FDG PET.     

缺氧对H9C2心肌细胞膜葡萄糖转运蛋白表达量的影响

目的观察缺氧对H9C2心肌细胞膜葡萄糖转运蛋白（GLUT1和GLUT4）表达量的影响。方法将H9C2心肌细胞随机分为对照组、胰岛素组、叠氮钠模拟的缺氧组，提取各实验组细胞膜后，用蛋白质印记杂交法测定膜组份中GLUTs的表达量。结果同对照组相比，胰岛素组和缺氧组细胞膜GLUTs表达量均明显增加，且胰岛素组对细胞膜GLUTs表达量的影响高于缺氧组（P〈0．05）。结论缺氧诱导H9C2心肌细胞膜GLUTs表达量增加，此种增加至少部分程度上介导了缺氧状态下H9C2心肌葡萄糖转运活动。     

Altered glucose transport to utero-embryonic unit in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx

The aim of this study was to compare the changes in concentration of glucose and glucose transporters (GLUTs) in the utero-embryonic unit, consisting of decidua, trophoblast and embryo, during delayed and non-delayed periods to understand the possible cause of delayed embryonic development in Cynopterus sphinx. The results showed a significantly decreased concentration of glucose in the utero-embryonic unit due to decline in the expression of insulin receptor (IR) and GLUT 3, 4 and 8 proteins in the utero-embryonic unit during delayed period. The in vitro study showed suppressive effect of insulin on expression of GLUTs 4 and 8 in the utero-embryonic unit and a significant positive correlation between the decreased amount of glucose consumed by the utero-embryonic unit and decreased expression of GLUTs 4 (r=0.99; p<0.05) and 8 (r=0.98; p<0.05). The in vivo study showed expression of IR and GLUT 4 proteins in adipose tissue during November suggesting increased transport of glucose to adipose tissue for adipogenesis. This study showed increased expression of HSL and OCTN2 and increased availability of l-carnitine to utero-embryonic unit suggesting increased transport of fatty acid to utero-embryonic unit during the period of delayed embryonic development. Hence it appears that due to increased transport of glucose for adipogenesis prior to winter, glucose utilization by utero-embryonic unit declines and this may be responsible for delayed embryonic development in C. sphinx. Increased supply of fatty acid to the delayed embryo may be responsible for its survival under low glucose condition but unable to promote embryonic development in C. sphinx.     

黄芩苷、小檗碱和葛根素体外胰岛素抵抗细胞差异化降糖作用研究

探讨中药成分黄芩苷、小檗碱、葛根素和甘草苷对肝胰岛素抵抗(insulin resistance,IR)细胞糖代谢的改善作用。采用胰岛素和地塞米松联合诱导建立IR-HepG2细胞模型,给药24 h测定不同剂量黄芩苷、小檗碱、葛根素和甘草苷对葡萄糖消耗量、糖原含量和细胞活性的影响。结果显示,与IR模型组相比,除甘草苷和1μmol·L-1黄芩苷组外,各给药组均显著升高葡萄糖消耗量;黄芩苷组(10,20,50μmol·L-1)、小檗碱组(5,10,20,50μmol·L-1)和葛根素组(40,80,160μmol·L-1)显著增加细胞内肝糖原含量;而甘草苷降糖作用不明显。在此基础上,重点研究黄芩苷、小檗碱和葛根素对IR-HepG2细胞葡萄糖转运蛋白(GLUTs)表达水平的影响。q PCR结果显示IR-HepG2细胞GLUT1和GLUT4基因mRNA表达比正常组低。5,20μmol·L-1小檗碱下调IR-HepG2细胞GLUT1基因mRNA水平;20,40,80μmol·L-1葛根素上调GLUT1基因mRNA水平。10,20,50μmol·L-1黄芩苷和20μmol·L-1小檗碱上调GLUT4基因mRNA水平,40,80μmol·L-1葛根素下调GLUT4基因mRNA水平。Western blot法检测结果显示,与正常组相比,IR-HepG2细胞GLUT1和GLUT4蛋白表达降低,GLUT2表达升高。10,20,50μmol·L-1黄芩苷上调GLUT2和GLUT4蛋白表达;20μmol·L-1小檗碱升高GLUT2蛋白表达,10,20μmol·L-1小檗碱增加GLUT4蛋白表达;20,40,80μmol·L-1葛根素上调GLUT1和GLUT2蛋白表达。以上成分体外差异化影响GLUT1/2/4表达,可以有效调节葡萄糖转运的瞬时响应和长期响应。降糖途径分析显示黄芩苷和葛根素与油酸诱导IR-HepG2细胞降糖作用途径环节及效应强弱存在一定程度差异,而小檗碱和甘草苷在2种不同诱因的IR-HepG2细胞中无明显差异。体外研究初步表明黄芩苷、小檗碱和葛根素具有体外差异化降糖作用,可加速糖转运增加糖原合成调节糖代谢改善肝IR。     

心肌细胞葡萄糖转运机制的研究进展

葡萄糖是心肌能量代谢的主要底物之一,在心肌缺血/缺氧以及心脏负荷加重等代偿性适应阶段尤为重要。葡萄糖由细胞外向细胞内转运是心肌葡萄糖代谢的第一步,是心肌利用葡萄糖的限速步骤。葡萄糖进入心肌细胞主要通过易化性葡萄糖转运子家族(facilitativeglucosetransporters,GLUTs)实现。GLUTs的质和量对心肌葡萄糖跨膜转运的速度起决定作用。因此,明确心肌葡萄糖转运及心肌葡萄糖转运子表达的调控机制对生理条件下葡萄糖内稳态的调节以及病理状态下心肌能量代谢的纠正及心肌功能的改善都具有重要意义。本文将对近几年来有关心肌葡萄糖转运及葡萄糖转运子调控方面的研究进行综述。     

Regulation of Vitamin C Homeostasis during Deficiency

Large cross-sectional population studies confirm that vitamin C deficiency is common in humans, affecting 5%–10% of adults in the industrialized world. Moreover, significant associations between poor vitamin C status and increased morbidity and mortality have consistently been observed. However, the absorption, distribution and elimination kinetics of vitamin C in vivo are highly complex, due to dose-dependent non-linearity, and the specific regulatory mechanisms are not fully understood. Particularly, little is known about how adaptive mechanisms during states of deficiency affect the overall regulation of vitamin C transport in the body. This review discusses mechanisms of vitamin C transport and potential means of regulation with special emphasis on capacity and functional properties, such as differences in the K_m of vitamin C transporters in different target tissues, in some instances demonstrating a tissue-specific distribution.     

阿魏酸对脑梗死大鼠的神经功能、GLUT蛋白与神经元葡萄糖代谢的影响

目的 探究阿魏酸在减轻大鼠脑梗死过程中对葡萄糖转运蛋白（GLUTs）和神经元葡萄糖代谢的影响。方法 72只SD大鼠随机分为假手术组、模型组、尼莫地平组以及阿魏酸25、50、100 mg/kg组。采用Longa线栓法构建脑梗死模型，梗死期间，模型组尾iv生理盐水，阿魏酸组分别尾iv 25、50、100 mg/kg的阿魏酸治疗，尼莫地平组尾iv 20 mg/kg尼莫地平，给药3 d。完成给药后24 h，对各组大鼠开展神经功能评分，完成后取大鼠血液检测外周血糖值，再通过PET/CT实验检测缺血区葡萄糖摄取水平。将大鼠处死后全脑组织进行TTC染色，取缺血核心区组织，通过比色法检测ATP含量，采用Western blotting法检测GLUT蛋白表达水平。结果 与假手术组比较，模型组大鼠神经功能评分增加，出现明显梗死区域，缺血核心区葡萄糖摄取量减少，ATP含量降低，GLUT1、GLUT3、PFKFB3蛋白表达降低（P＜0.05）。与模型组比较，阿魏酸50、100 mg/kg组大鼠神经功能评分减少，梗死区域面积占比减少，缺血核心区葡萄糖摄取量增加，ATP含量升高，GLUT1、GLUT3、PFKFB3蛋白表达升高（P＜0.05）。结论 阿魏酸对脑梗死大鼠的治疗效果与尼莫地平相似，其机制可能与提高GLUT1和GLUT3蛋白表达，促进葡萄糖向中枢神经元转运，提高葡萄糖代谢相关。