Effect of Choline-Containing Phospholipids on Transglutaminase Activity in Primary Astroglial Cell Cultures

The aim of the present investigation was to study the effects of choline and choline-containing phospholipids CDP-choline (CDPC) and L-alpha-glyceryl-phosphorylcholine (AGPC) on transglutaminase (TG) activity and expression in primary astrocyte cultures. TG is an important Ca²⁺-dependent protein that represents a normal constituent of nervous systems during fetal stages of development, playing a role in cell signal transduction, differentiation, and apoptosis. Confocal laser scanning microscopy (CLSM) analysis showed an increase of TG activity in astrocyte cultures treated with choline, CDPC, or AGPC at 0.1 μM or 1 μM concentrations. Comparatively, AGPC induced the most conspicuous effects enhancing monodansyl-cadaverine fluorescence both in cytosol and in nuclei, supporting the evidence of the important role played by AGPC throughout differentiation processes tightly correlated to nucleus-cytosol cross- talk during astroglial cells proliferation and development. Western blot analysis showed that in 24h 1 μM AGPC and choline-treated astrocytes increased TG-2, whereas no effect was observed in 24h 1 μM CDP-choline treated astrocytes. Our data suggest a crucial role of choline precursors during different stages of astroglial cell proliferation and differentiation in cultures.     

Transfer of lipids to high-density lipoprotein (HDL) is altered in patients with familial hypercholesterolemia

Objective

In familial hypercholesterolemia (FH), the metabolism and anti-atherogenic functions of HDL can be affected by the continuous interactions with excess LDL amounts. Here, lipid transfers to HDL, an important step for HDL intravascular metabolism and for HDL role in reverse cholesterol transport (RCT) were investigated in FH patients.

Methods

Seventy-one FH patients (39 ± 15 years, LDL-cholesterol = 274 ± 101; HDL-cholesterol = 50 ± 14 mg/dl) and 66 normolipidemic subjects (NL) (38 ± 11 years, LDL-cholesterol = 105 ± 27; HDL-cholesterol = 52 ± 12 mg/dl) were studied. In vitro, lipid transfers were evaluated by incubation of plasma samples (37 °C, 1 h) with a donor lipid nanoemulsion labeled with 3H-triglycerides (TG) and 14C-unesterified cholesterol (UC) or with 3H-cholesteryl ester (EC) and 14C-phospholipids (PL). Radioactivity was counted at the HDL fraction after chemical precipitation of apolipoprotein (apo) B-containing lipoproteins and the nanoemulsion. Data are % of total radioactivity measured in the HDL fraction.

Results

Transfer of UC to HDL was lower in FH than in NL (5.6 ± 2.1 vs 6.7 ± 2.0%, p = 0.0005) whereas TG (5.5 ± 3.1 vs 3.7 ± 0.9%, p = 0.018) and PL (20.9 ± 4.6 vs 18.2 ± 3.7 %, p = 0.023) transfers were higher in FH. EC transfer was equal. By multivariate analysis, transfers of all four lipids correlated with HDL-cholesterol and with apo A-I.

Conclusion

FH elicited marked changes in three of the four tested lipid transfers to HDL. The entry of UC into HDL for subsequent esterification is an important driving force for RCT and reduction of UC transfer to HDL was previously associated to precocious coronary heart disease. Therefore, in FH, HDL functions can be lessened, which can also contribute to atherogenesis.     

Effect of Moderate Freshwater Fish Diet on Erythrocyte Ghost Phospholipid Fatty Acids

Dose responses over 12 weeks of meals containing fish on erythrocyte phospholipids were studied in male students. In all major glycerophospholipids the proportions of long chain n-3 fatty acids increased at the expense of n-6 fatty acids with 1.5 meals a week containing fish (0.5 g n-3 fatty acids per day). The rates and magnitudes of changes varied for individual phospholipids: faster but quantitatively smaller changes occurred in phosphatidylcholine than in phosphatidylethanolamine and phosphatidylserine. Fish diet and fish oil studies have usually been made using large doses over a short time. Our results show that similar effects might result from smaller amounts given over a longer time.     

十六角蒙脱石对大鼠急性胃粘膜损伤的预防和治疗作用

目的：研究十六角蒙脱石对大鼠急性胃粘膜损伤的防治作用。方法：４８只大鼠随机分为７个组，正常对照组、无水乙醇预防和治疗对照组、２个药物预防组、２个治疗组。其中预防组分别给予十六角蒙脱石０．１５ｇ／ｋｇ和雷尼替丁５ｍｇ／ｋｇｉｇ２次，再各ｉｇ无水乙醇０．７５ｍＬ／只；２个治疗组，先无水乙醇１ｍＬ／只ｉｇ，再分别给予十六角蒙脱石和雷尼替丁，每天剂量同上，ｉｇ１ｗｋ。结果：十六角蒙脱石无论是预防或治疗皆显著降低无水乙醇所致胃粘膜的损伤指数（ＩＩ），增加血流量，升高胃粘膜电位（ＰＤ），增加氨基己糖、磷脂含量和增强疏水性（Ｐ＜０．０１或＜０．０５）。而雷尼替丁治疗组仅对ＩＩ和ＰＤ有显著影响，结论：十六角蒙脱石是一种良好的胃粘膜防护剂。     

兔磷脂抗炎免疫药理学研究

兔脑含77%水,9.6%蛋白质,3.1%胆固醇,3.4%兔磷脂(1.5%卵磷脂,1.9%脑磷脂)和 Fe,Zn,Cu,Mn,Ca,Mg 等元素。兔磷脂(RBP)对四种急性渗出性炎症动物模型有显著抗炎作用,卵磷脂和脑磷脂为抗急性炎症的有效成分。但对慢性增生性炎症动物模型无抗炎作用。对正常或免疫受抑动物,RBP 能增加脾重,提高碳粒廓清率和腹腔巨噬细胞吞噬指数,提高淋巴细胞转化和抗体生成水平及肝细胞 cGMP 含量;在体外,小剂量 RBP 促正常人淋巴细胞增殖反应,大剂量呈抑制作用。     

兔磷脂对小鼠免疫功能的影响

为了探讨兔磷脂对免疫功能的影响,实验采用一定剂量的兔磷脂对强的松龙所致的小鼠免疫受抑动物模型进行免疫调节治疗,结果:兔磷脂可提高免疫受抑动物脾脏的重量(P<0.01),显著提高脾细胞介导的红细胞溶血水平(P<0.01),还可增强淋巴细胞增殖能力(P<0.05),并提高肝组织中环磷酸鸟苷(cGMP)的含量(P<0.05)。实验表明免磷脂具有调节和增强免疫功能作用。     

Pulmonary surfactant: No mere paint on the alveolar wall

Abstract The gas-liquid interface within the alveolus is completely lined with a complex mixture of lipids and unique proteins termed pulmonary surfactant, which both reduces surface tension and permits it to vary directly with the radius of curvature. In this way it minimizes the work of breathing and permits alveoli of different sizes to exist in equilibrium. However, surfactant does far more in that it also controls fluid balance in the lung and appears to play a key role in host defence. Either a deficiency in surfactant or an aberrant surfactant results in atelectasis and oedema. The surfactant system is very dynamic: alveolar surfactant phosphatidylcholine, the principal component, having a half life of only a few hours, with as much as 85% being recycled. Although distortion of the alveolar type II cell is now accepted as the principal stimulus for release, much remains to be discovered of modulating factors and intracellular signalling in the control of surfactant homeostasis. Likewise, many questions remain concerning the control of synthesis of the surfactant phospholipids, neutral lipids and proteins and their assembly into the tubular myelin form of alveolar surfactant, the refining of the monolayer with breathing, the control of re-uptake of different components into the type II cells and the roles of the proteins.     

Regionally specific alterations in membrane phospholipids in children with ADHD: An in vivo P spectroscopy study

This multi-voxel, phosphorus magnetic resonance spectroscopy (³¹P MRS) study examined the prefrontal cortex (PFC), basal ganglia (BG) and superior temporal (ST) region in 10 children with attention-deficit/hyperactivity disorder (ADHD) and 15 healthy controls. ADHD patients had lower PFC and BG phosphomonoester (PME) levels compared to healthy children. No differences were noted in the ST. These deficits in membrane phospholipid (MPL) precursor levels suggest reduced mass of cellular MPLs due to a possible underdevelopment of neuronal processes and synapses in ADHD.     

Effect of low-dose lead acetate exposure on the metabolism of nucleic acids and lipids in cerebellum and hippocampus of rat during postnatal development

Postnatal exposure (from the second day after birth to 30 days) of rat pups to low levels of lead acetate (50 mg/kg body weight/day), administered by gastric intubation, yielded a maximum blood level of 76.1 micrograms/100 ml, at day 15 of age. Cerebellar and hippocampal lead contents were 8.67 micrograms/100 mg and 11.7 micrograms/100 mg, respectively, at day 30 of age. This lead exposure has been shown to elicit little change in some biochemical parameters in cerebellum and hippocampus. At the three ages investigated (5, 15, and 30 days after birth) there were no alterations of body weight; brain, cerebellum, and hippocampus wet weight; and DNA, RNA, protein and phospholipid content, either in total tissue or in mitochondria. A similar invariance following lead exposure was observed in mitochondrial succinate dehydrogenase and cytochrome oxidase activities. After intraperitoneal administration, the incorporation of [methyl-14C]thymidine into DNA and [5,6-3H]uridine into RNA of cerebellum and hippocampus showed a significant decrease only at day 5, reaching the control value at 15 and 30 days of age. After intraperitoneal injection, [2-3H]glycerol incorporation into total lipids and phospholipids of cerebellum and hippocampus also showed no significant changes in Pb-treated pups compared to controls at all three postnatal ages. We concluded that subclinical lead administration exerts its effect by slowing cell proliferation in the very early growth phase of the brain. It is likely that a metabolic compensative response to subtoxic effect of lead acetate may be brought about in cerebellum and hippocampus during critical phases of nervous system development between days 15 and 30.     

冠心病肾阳虚证血脂特点

目的：了解肾阳虚证在冠心病不同亚型中的地位及其脂特点。方法：对18例心肌梗死和43例心绞痛住院患者检测24小时尿17羟及TC、TG、HDLc,HDL3c,HDL-PL。冠心病诊断参照WHO标准，肾阳虚证参照24小时尿17羟低于正常值，结果：（1）冠心病肾阳虚证发生率与西医分型关系密切，心肌梗死肾阳虚证发生率（13／18）显著高于心绞痛组（13／43）；（2）冠心病肾阳虚证HDL3c,HDL-PL显著低于其它证型。结论：冠心病肾阳虚证血脂代谢严重紊乱，以胆固醇逆向转运障碍进一步加重为特征。