Adverse effect of obesity on red cell membrane arachidonic and docosahexaenoic acids in gestational diabetes

Aims/hypothesis Gestational diabetes is a metabolic disorder affecting 2–5% of women and is a predictor of obesity, Type 2 diabetes mellitus and cardiovascular disease. Insulin resistance, a characteristic of gestational diabetes and obesity, is correlated with the fatty acids profile of the red cell and skeletal muscle membranes. We investigated the plasma and red cell fatty acid status of gestational diabetes. The effect of obesity on membrane fatty acids was also examined.Methods Fasting blood obtained at diagnosis was analysed for the fatty acids in plasma choline phosphoglycerides and red cell choline and ethanolamine phosphoglycerides.Results There were reductions in arachidonic acid (controls 10.74±2.35 vs gestational diabetes 8.35±3.49, p<0.01) and docosahexaenoic acid (controls 6.31±2.67 vs gestational diabetes 3.25±2.00, p<0.0001) in the red cell choline phosphoglycerides in gestational diabetes. A similar pattern was found in the ethanolamine phosphoglycerides. Moreover, the arachidonic and docosahexaenoic acids depletion in the red cell choline phosphoglycerides was much greater in overweight/obese gestational diabetes (arachidonic acid=7.49±3.37, docosahexaenoic acid=2.98±2.18, p<0.01) compared with lean gestational diabetes (arachidonic acid=10.03±2.74, docosahexaenoic acid=4.18±1.42).Conclusion/interpretation Apparently normal plasma choline phosphoglycerides fatty acids profile in the gestational diabetic women suggested that membrane lipid abnormality is associated specifically with perturbation in the membrane. The fact that the lipid abnormality is more pronounced in the outer leaflet of the membrane where most of receptor binding and enzyme activities take place might provide an explanation for the increased insulin resistance in gestational diabetes and obesity.Abbreviations AA arachidonic acid - CPG choline phosphoglycerides - DHA docosahexaenoic acid - EPG ethanolamine phosphoglycerides - FAME fatty acid methyl esters - GDM gestational diabetes mellitus     

离子色谱法测定氯化琥珀胆碱原料及注射液中的氯化胆碱和氯化琥珀酰单胆碱

目的 采用离子色谱法测定氯化琥珀胆碱原料及注射液中的氯化胆碱和氯化琥珀酰单胆碱。方法 采用Dionex RFICTM Ionpac CS17色谱柱（4 mm×250 mm）,以甲烷磺酸溶液为流动相进行梯度洗脱,流速为1.0 mL·min^-1,采用抑制电导检测器进行测定。结果 氯化胆碱、氯化琥珀酰单胆碱浓度分别在18.0~562.8 μg·mL^-1（r=0.999 9）和14.4~449.8 μg·mL^-1（r=0.999 9）内线性关系良好,定量限均为0.01 μg·mL^-1。原料中氯化胆碱、氯化琥珀酰单胆碱回收率分别为103.4%~105.7%和102.4%~107.1%;注射液中氯化胆碱、氯化琥珀酰单胆碱回收率分别为95.6%~100.2%和94.4%~103.5%。结论 该方法专属性强、准确、简便、快速,适用于氯化琥珀胆碱原料及制剂中的有关物质测定。     

Morphological and physiological properties of enhanced green fluorescent protein (EGFP)‐expressing wide‐field amacrine cells in the ChAT‐EGFP mouse line

Mammalian retinas comprise a variety of interneurons, among which amacrine cells represent the largest group, with more than 30 different cell types each exhibiting a rather distinctive morphology and carrying out a unique function in retinal processing. However, many amacrine types have not been studied systematically because, in particular, amacrine cells with large dendritic fields, i.e. wide‐field amacrine cells, have a low abundance and are therefore difficult to target. Here, we used a transgenic mouse line expressing the coding sequence of enhanced green fluorescent protein under the promoter for choline acetyltransferase (ChAT‐EGFP mouse) and characterized a single wide‐field amacrine cell population monostratifying in layer 2/3 of the inner plexiform layer (WA‐S2/3 cell). Somata of WA‐S2/3 cells are located either in the inner nuclear layer or are displaced to the ganglion cell layer and exhibit a low cell density. Using immunohistochemistry, we show that WA‐S2/3 cells are presumably GABAergic but may also release acetylcholine as their somata are weakly positive for ChAT. Two‐photon‐guided patch‐clamp recordings from intact retinas revealed WA‐S2/3 cells to be ON‐OFF cells with a homogenous receptive field even larger than the dendritic field. The large spatial extent of the receptive field is most likely due to the extensive homologous and heterologous coupling among WA‐S2/3 cells and to other amacrine cells, respectively, as indicated by tracer injections. In summary, we have characterized a novel type of GABAergic ON‐OFF wide‐field amacrine cell which is ideally suited to providing long‐range inhibition to ganglion cells due to its strong coupling.     

Developmental profiles of various cholinergic markers in the rat main olfactory bulb using quantitative autoradiography

The existence of possible relationships among the developmental profile of various cholinergic markers in the main olfactory bulb (OB) was assessed by using in vitro quantitative autoradiography. Muscarinic receptors were visualized with [³H]pirenzepine (muscarinic M1-like sites) and [³H]AF-DX 384 (muscarinic M2-like sites); nicotinic receptors by using [³H]cytisine (nicotinic 42-like subtype) and [¹²⁵I]α-bungarotoxin (nicotinic 7-like subtype); cholinergic nerve terminals by using [³H]vesamicol (vesicular acetylcholine transport sites) and [³H]hemicholinium-3 (high-affinity choline uptake sites). These various cholinergic markers exhibited their lowest levels at birth and reached adult values by the end of the 4–5 postnatal weeks. However, the density of presynaptic cholinergic markers and nicotinic receptors at postnatal day 2 represented a large proportion of the levels observed in adulthood, and displays a transient overexpression around postnatal day 20. In contrast, the postnatal development of cholinergic muscarinic M1-like and M2-like receptors is apparently regulated independently of the presynaptic cholinergic markers and nicotinic receptors. Two neurochemically and anatomically separate olfactory glomeruli subsets were observed in the posterior OB of the developing rat. These atypical glomeruli expressed large amounts of [³H]vesamicol- and [³H]hemicholinium binding sites without significant amounts of muscarinic M1, M2, or nicotinic α4β2 receptor binding sites. A significant density of [¹²⁵I]α-bungarotoxin binding sites could be detected only at early postnatal ages. A few olfactory glomeruli specifically restricted to the dorsal posterior OB expressed a high density of [³H]cytisine binding sites but lacked significant binding of the two presynaptic cholinergic markers used here, suggesting their noncholinergic but cholinoceptive nature. © 1996 Wiley-Liss, Inc.     

Mild Choline Deficiency and MTHFD1 Synthetase Deficiency Interact to Increase Incidence of Developmental Delays and Defects in Mice

Folate and choline are interconnected metabolically. The MTHFD1 R653Q SNP is a risk factor for birth defects and there are concerns that choline deficiency may interact with this SNP and exacerbate health risks. 80–90% of women do not meet the Adequate Intake (AI) for choline. The objective of this study was to assess the effects of choline deficiency on maternal one-carbon metabolism and reproductive outcomes in the MTHFD1-synthetase deficient mouse (Mthfd1S), a model for MTHFD1 R653Q. Mthfd1S^+/+ and Mthfd1S^+/− females were fed control (CD) or choline-deficient diets (ChDD; 1/3 the amount of choline) before mating and during pregnancy. Embryos were evaluated for delays and defects at 10.5 days gestation. Choline metabolites were measured in the maternal liver, and total folate measured in maternal plasma and liver. ChDD significantly decreased choline, betaine, phosphocholine, and dimethylglycine in maternal liver (p < 0.05, ANOVA), and altered phosphatidylcholine metabolism. Maternal and embryonic genotype, and diet-genotype interactions had significant effects on defect incidence. Mild choline deficiency and Mthfd1S^+/− genotype alter maternal one-carbon metabolism and increase incidence of developmental defects. Further study is required to determine if low choline intakes contribute to developmental defects in humans, particularly in 653QQ women.     

胆碱对急性心肌缺血心律失常的作用

目的 观察胆碱对大鼠急性心肌缺血的作用,并探讨其作用机制.方法 以结扎大鼠左冠状动脉前降支造成急性心肌缺血模型,给予M受体激动剂胆碱和M3受体阻断剂4DAMP进行干预.观察大鼠急性心肌缺血模型心律失常发生情况和心肌细胞L型钙通道蛋白mRNA的表达.结果 ①胆碱可降低大鼠急性心肌缺血模型的心律失常发生率(P＜0.05);②胆碱能够使L型钙通道mRNA表达增加;③M3受体阻断剂4DAMP可逆转胆碱的上述作用(P＜0.05).结论 胆碱通过激活M3受体降低了急性心肌缺血大鼠心律失常的发生率.     

Prenatal Folate and Choline Levels and Brain and Cognitive Development in Children: A Critical Narrative Review

Women’s nutritional status during pregnancy can have long-term effects on children’s brains and cognitive development. Folate and choline are methyl-donor nutrients and are important for closure of the neural tube during fetal development. They have also been associated with brain and cognitive development in children. Animal studies have observed that prenatal folate and choline supplementation is associated with better cognitive outcomes in offspring and that these nutrients may have interactive effects on brain development. Although some human studies have reported associations between maternal folate and choline levels and child cognitive outcomes, results are not consistent, and no human studies have investigated the potential interactive effects of folate and choline. This lack of consistency could be due to differences in the methods used to assess folate and choline levels, the gestational trimester at which they were measured, and lack of consideration of potential confounding variables. This narrative review discusses and critically reviews current research examining the associations between maternal levels of folate and choline during pregnancy and brain and cognitive development in children. Directions for future research that will increase our understanding of the effects of these nutrients on children’s neurodevelopment are discussed.     

Transforming growth factor‐α attenuates hepatic fibrosis: possible involvement of matrix metalloproteinase‐1

Background: The effect of transforming growth factor (TGF)‐α on fibrosis varies between cell types and the role of TGF‐α in hepatic fibrosis has not been fully elucidated. Methods: We examined the effect of TGF‐α on hepatic fibrosis using TGF‐α‐expressing transgenic mice fed a methionine‐ and choline‐deficient (MCD) diet and human hepatic stellate cells (HSCs) line LX‐2, rat and human primary HSCs. Results: Although the expression levels of the tissue inhibitor of metalloproteinases‐1 and α1(I) collagen mRNA were unchanged, feeding the TGF‐α transgenic mice the MCD diet resulted in greater expression of the murine functional analogue of matrix metalloproteinase‐1 (MMP‐1), MMP‐13 mRNA and protein and attenuated hepatic fibrosis compared with wild‐type mice. TGF‐α overexpression did not affect the extent of the steatosis, oxidative stress and hepatic inflammation in the MCD diet‐fed mice. The effect of TGF‐α on the fibrogenic and anti‐fibrogenic gene expressions varied between cell types in vitro. TGF‐α increased MMP‐1 mRNA expressions that were completely blocked by gefitinib in LX‐2 cells. The extracellular signal‐regulated kinase (ERK) 1/2, c‐Jun N‐terminal kinase and p38 pathways were involved in MMP‐1 mRNA expression in LX‐2 cells. Although TGF‐α increased the phosphorylation of p38, the p38 inhibitor activated the RAS‐ERK pathway and increased TGF‐α‐induced MMP‐1 mRNA expression, which suggested that there may be a crosstalk between the RAS‐ERK and the p38 pathways in LX‐2 cells. Conclusions: The TGF‐α may attenuate hepatic fibrosis in part because of upregulation of the expression of MMP‐1. The balance between fibrogenic and anti‐fibrogenic gene expression and between the activity of the RAS‐ERK and the p38 pathways may be crucial for the fibrotic process.