银杏牛蒡混合发酵食品对小鼠衰老指标的影响

目的：研究一种以银杏叶、牛蒡提取物为主成分的发酵食品(GBF)对小鼠衰老指标的影响。方法：以D-半乳糖造衰老模型,以每只每天0．5ml剂量的GBF对小鼠灌胃,以不喂GBF的衰老模型小鼠为对照,以正常饲养的小鼠为空白对照(CK),42d后研究其对衰老相关指标组织单胺氧化酶、丙二醛含量、羟脯氨酸含量和腹腔巨噬细胞吞噬活性的影响。结果：喂食GBF的小鼠肝,脑组织中单胺氧化酶的活性比对照降低了36．7%和25．1%,丙二醛含量比对照降低了19%和44．6%。差异达到统计学显著水平(p＜0．05);而皮肤组织中羟脯氨酸含量和巨噬细胞吞噬活性分别高于对照28．6%和63．2%,显著高于对照(p＜0．05)。结论：GBF具有显著抗衰老活性。     

Antigen of "serum sickness" type of heterophile antibodies in human sera: indentification as gangliosides with N-glycolylneuraminic acid.

Antigen of “serum-sickness” type of heterophile antibodies in pathologic human sera was purified from equine and bovine erythrocyte stroma. The chemical nature of this antigen was glycosphingolipids with N-glycolylneuraminic acid. The antigen of equine erythrocytes was identified as hematoside with N-glycolylneuraminic acid, GlNeu(α, 2–3)Gal(β, 1–4)Glc(β,1-1) ceramide and the antigen of bovine erythrocytes was N-glycolylneuraminyl-paragloboside, GlNeu (α,2–3)Gal(β,1–4)GlcNAc(β,1–3)Gal(β,1–4)Glc(β,1-1) ceramide. The results indicate that “serum-sickness” antibodies react with a common disaccharide moiety of non-reducing end of the both glycosphingolipids.     

Comparative modeling and genomics for galactokinase (Gal1p) enzyme

The Gal1p (Galactokinase) protein is known for regulation of D-galactose metabolism. It catalyzes the formation of galactose -1-phosphate from alpha - D-galactose, which is an important step in galactose catabolism. The knowledge of Gal1p protein structure, its protein interacting partners and enumeration of functional site residues will provide great insight in understanding the functional role of Gal1p. These studies are lacking in case of the Gal11p kinase enzyme. Structure of this enzyme has already been determined in S. cerevisiae, however, no structural information for this protein is available for K. lactis and E. coli. We used the homology modeling based approach to model the structures of Gal1p for K. lactis and E. coli. Furthermore, functional residues were predicted for these Gal1 proteins and the strength of interaction between Gal1p and other Gal proteins was determined by protein-protein interaction studies via patchdock software. The interaction studies revealed that the affinity for Gal1p for other Gal proteins varies in different organisms. Sequence and structural based comparison of Gal1p kinase enzyme showed that the orthologs in K.lactis and S. cervisiae are more similar to each other as compared to the ortholog in E. coli. These studies carried out by us will help in better understanding of the galactose metabolism. Our sequence and structure comparison studies revealed that Human Gal1p shows more homology for Gal1p protein of E. coli. The above studies may be applied to Human Gal1p, where it can help in gaining useful insight into Galactosemia disease.     

D-半乳糖诱导大鼠脑损伤的糖基化机制

目的D-半乳糖（D-galactose）诱导大鼠体内不同糖基化水平,研究其脑损伤发生的机理。方法采用不同剂量D-半乳糖[150、75、37．5mg／（kg·d）]分别腹腔注射（ip）处理大鼠8周,诱导糖基化状态和脑损伤。采用硫代巴比妥酸（TBA）比色法测定糖化血红蛋白,硝基四氮唑蓝（NBT）比色法测定血清果糖胺;按文献方法分别测定血红细胞醛糖还原酶活性和晚期糖基化终末产物（AGEs）含量及脑组织中AGEs含量,羟胺法和比色法分别测定SOD和GSH-Px活性,硫代巴比妥酸法测定MDA含量;以Fura-2／AM作为钙荧光指示剂,双波长荧光分光光度法检测脑海马神经细胞胞质[Ca^2＋]i的变化;透射电镜观察脑海马神经细胞线粒体的变化。结果D-半乳糖处理8周后,大鼠血红细胞醛糖还原酶活性升高,糖化产物形成增多;脑组织中AGEs及脑细胞胞质[Ca^2＋]i含量明显升高,SOD及GSH-Px活性下降,MDA含量升高（P〈0．01,P〈0．05）,海马神经细胞线粒体出现病理性改变。结论D-半乳糖通过诱导体内蛋白糖基化和脑组织AGEs大量生成,降低抗氧化能力及胞质[Ca^2＋]i超负荷等,导致脑细胞损伤。     

Features of T-cell subset composition in a D-galactose-induced senescence mouse model

Long-term administration of D-galactose induces oxidative stress and accelerates normal age-related changes. Hence, the D-galactose-treated rodent model has been widely used for aging research. In this study, we examined the immunological characteristics, especially CD4⁺ T-cell subset composition, of D-galactose-induced aging model mice to evaluate the model’s utility in immunosenescence studies. The spleens of aging model mice subjected to repeated subcutaneous injections of D-galactose exhibited significant increases in T cells with the memory phenotype (CD62L^low CD44^high) and individual T-cell subsets (Th1, Th2, Th17 and T_reg). Furthermore, cells with the phenotype of T follicular helper (Tfh) cells were spontaneously increased. The features of T-cell subset composition in D-galactose-treated mice were in close agreement with those observed in normal aged mice and appeared to mimic the currently known normal aging processes associated with T-cell homeostasis. Our results suggest that D-galactose-induced aging models would be useful for immunosenescence studies focusing on T-cell homeostasis and give valuable insight into age-related immune system dysregulation.     

Calcium-cadmium interaction on sugar absorption across the rabbit jejunum

The element Cd is considered to have no biological function and is highly toxic to humans and animals. Toxic effects of this metal upon cell membrane structure and function have been shown. On the other hand, Ca is an essential element in a wide variety of cellular activities. The present study was initiated to research whether the interaction between Ca and Cd could affect D-galactose absorption across the rabbit jejunum in vitro. In media with Ca²⁺, when CdCl₂ was present at 0.5 or 1 mM, Cd was found to significantly reduce the sugar absorption. In Ca²⁺-free media, where CaCl₂, was omitted and replaced isotonically with choline chloride, the sugar transport was not modified by Cd, but when CaCl₂ was replaced isotonically with MgCl₂, the inhibition is observed. Verapamil at 10⁻⁶ M (blocking mainly Ca²⁺ transport) did not modify the inhibitory effect of cadmium on D-galactose transport. When 10⁻⁶ M of A 23187 (Ca²⁺ specific ionophore) was added in media with/without Ca²⁺; CdCl₂ produced no change in D-galactose transport. These results suggest that Ca and Cd could have affinity for the same chemical groups of enterocyte membrane, which would be related with the intestinal absorption of D-galactose.     

Ergothioneine and melatonin attenuate oxidative stress and protect against learning and memory deficits in C57BL/6J mice treated with D-galactose

Abstract

Male C57BL/6J mice treated with D-galactose (DG) were used to examine the effects of ergothioneine (EGT), melatonin (MEL), or their combination (EGT+MEL) on learning and memory abilities. The mice were divided into five groups and injected subcutaneously with DG (0.3 mL of 1% DG/mouse) except for group 1 (normal controls). Group 3 was orally supplemented with EGT [0.5 mg/kg body weight (bw)], group 4 with MEL (10 mg/kg bw, p.o.), and group 5 with EGT+MEL. EGT and MEL were provided daily for 88 days, while DG was provided between days 7 to 56. Active avoidance task and Morris water-maze task were used to evaluate learning and memory abilities. DG treatment markedly increased escape latency and decreased the number of avoidance in the active avoidance test, whereas EGT and MEL alone significantly improved the performance. DG also impaired the learning and memory abilities in the water-maze task, and EGT and MEL alone also significantly improved the performance. EGT+MEL produced the strongest effects in both tasks. EGT and MEL alone markedly decreased β-amyloid protein accumulation in the hippocampus and significantly inhibited lipid peroxidation and maintained glutathione/glutathione disulfide ratio and superoxide dismutase activity in brain tissues of DG-treated mice. MEL alone completely prevented the rise in brain acetylcholine esterase activity induced by DG, whereas EGT and EGT+MEL were only partially effective. Overall, EGT, MEL, and, in particular, the combination of EGT and MEL effectively protect against learning and memory deficits in C57BL/6J mice treated with DG, possibly through attenuation of oxidative damage.     

Availability of the key metabolic substrates dictates the respiratory response of cancer cells to the mitochondrial uncoupling

Active glycolysis and glutaminolysis provide bioenergetic stability of cancer cells in physiological conditions. Under hypoxia, metabolic and mitochondrial disorders, or pharmacological treatment, a deficit of key metabolic substrates may become life-threatening to cancer cells. We analysed the effects of mitochondrial uncoupling by FCCP on the respiration of cells fed by different combinations of Glc, Gal, Gln and Pyr. In cancer PC12 and HCT116 cells, a large increase in O₂ consumption rate (OCR) upon uncoupling was only seen when Gln was combined with either Glc or Pyr. Inhibition of glutaminolysis with BPTES abolished this effect. Despite the key role of Gln, addition of FCCP inhibited respiration and induced apoptosis in cells supplied with Gln alone or Gal/Gln. For all substrate combinations, amplitude of respiratory responses to FCCP did not correlate with Akt, Erk and AMPK phosphorylation, cellular ATP, and resting OCR, mitochondrial Ca^2 + or membrane potential. However, we propose that proton motive force could modulate respiratory response to FCCP by regulating mitochondrial transport of Gln and Pyr, which decreases upon mitochondrial depolarisation. As a result, an increase in respiration upon uncoupling is abolished in cells, deprived of Gln or Pyr (Glc). Unlike PC12 or HCT116 cells, mouse embryonic fibroblasts were capable of generating pronounced response to FCCP when deprived of Gln, thus exhibiting lower dependence on glutaminolysis. Overall, the differential regulation of the respiratory response to FCCP by metabolic environment suggests that mitochondrial uncoupling has a potential for substrate-specific inhibition of cell function, and can be explored for selective cancer treatment.     

运动训练和补肽抗大鼠骨骼肌衰老机制的初步研究

目的：观察6周负重训练和补充大豆多肽延缓I）_半乳糖大鼠骨骼肌衰老进程的作用效果,并探讨初步机制。方法：SD雄性大鼠3月龄60只,随机分为：6周安静组（C6）和6周模型组（M6）各6只,12周模型组（M12）、大负组（B12）、小负组（S12）、补肽组（P12）、补肽大负组（PB12）和补肽小负组（PS12）各8只,14月龄8只作为自然衰老组。分别于6周末和12周末处死大鼠,测试各项指标。结果：与C6相比,M6组大鼠各项指标出现不同程度的衰老表现;与M12组相比,负重或补肽可以显著提高各干预组大鼠骨骼肌超氧化物歧化酶（SOD）活力以及SOD/MDA,血清生长激素（GH）、胰岛素样生长因子I（IGF-I）含量和骨骼肌IGF-ImRNA表达量,降低骨骼肌丙二醛（MDA）含量,两种方式均具有明显的交互作用。结论：D-半乳糖6周皮下注射,能成功复制亚急性大鼠骨骼肌衰老模型,再经过6周负重训练或补肽均可以有效的缓解D-半乳糖大鼠骨骼肌的衰老进程,两者联合运用效果尤为明显。初步机制可能与减轻骨骼肌氧化应激以及脂质过氧化,纠正激素及相关因子的代谢紊乱,增加骨骼肌IGF-ImRNA的表达等有关。     

五鹤续断抗小鼠衰老的作用及其机制研究

目的：研究五鹤续断（WHDA）注射液对D-半乳糖所致小鼠衰老模型的抗衰老作用及其机制。方法：昆明种小鼠（雌雄各半）48只,随机分为对照组、模型组、阳性WHDA组、7．2g/kgWnDA组、3．6g/kgWHDA组及1．8g/kgWHDA组,每组8只。腹腔注射D-半乳糖造模,Morris水迷宫测量小鼠学习和记忆能力。检测各组小鼠皮肤羟脯氨酸、脑组织MDA、LP、SOD及GSH-Px含量,采用双抗体夹心ELISA法检测小鼠血清中IL-2及IL-6含量。结果：Morris水迷宫实验结果表明WHDA各组潜伏期与模型组相比较明显减少（P〈0．05）,模型组小鼠穿越平台的次数比其它各组小鼠少（P〈0．05）。脑组织氧化性指标（SOD、MAD、LP及GSH．Px）检测,对照组及WHDA各组MAD与LP含量低于模型组（P〈0．05）。对照组及WHDA各组SOD与GSH-Px的活性明显高于模型组（P〈0．05）。注射过D-半乳糖小鼠皮肤羟脯氨酸含量都明显低于对照组（P〈0．05）,WHDA组小鼠皮肤中羟脯氨酸的含量明显高于模型组（P〈0．05）。WHDA组小鼠血清中IL-2、IL-6含量显著高于对照组和模型组（P〈0．05）,模型组小鼠血清中的IL-2、IL-6比对照组要低（P〈0．05）。结论：WHDA能改善D．半乳糖所致的衰老小鼠的学习记忆能力,消除其体内自由基,增强机体免疫能力,具有较好的抗衰老作用。