Radioactive choline metabolism in guinea pig gallbladder

Acetylcholine may be released from gallbladder intrinsic nerves in response to cholecystokinin stimulation. This study characterized metabolites of [¹⁴C]choline produced in the gallbladder and released during incubation, with or without cholecystokinin-octapeptide. Radiolabeled [¹⁴C]choline was applied to the mucosal or muscle surface of intact guinea pig gallbladders in an organ bath. After radiolabeling, gallbladders were incubated with or without the contractile agonist cholecystokinin-octapeptide. Metabolites of [¹⁴C]choline were identified in gallbladder tissue and incubation buffers using HPLC and thin-layer chromatography. The major metabolites of [¹⁴C]choline were betaine and phosphocholine. [¹⁴C]Phosphocholine was incorporated slowly into [¹⁴C]phosphatidylcholine. [¹⁴C]Choline was released into buffers during incubation. [¹⁴C]Acetylcholine constituted less than 1% of radiolabel in the gallbladder. There was no identifiable [¹⁴C]acetylcholine released in buffers. Cholecystokinin-octapeptide did not affect choline metabolism. These studies showed that choline in the gallbladder is metabolized along pathways similar to those in the liver. Gallbladders released mostly choline, rather than acetylcholine, even during hormonally induced contraction.This project was supported by the Research and Development Office of the Department of Veterans Affairs.     

Focal differences in lipid metabolism of the young pig aorta : Part 2. Synthesis from [2-C]ethanolamine and [1,2-C]choline

The ability of normal young pig aortic tissue to synthesize phospholipids from [2-¹⁴C]ethanolamine and [1,2-¹⁴C]choline, in vitro, has been examined in areas of focal Evans Blue accumulation (blue areas) and adjacent areas of no dye accumulation (white areas).

Incorporation of [2-¹⁴C]ethanolamine into total lipid was linear for 3 h of incubation in both blue and white areas. At 3 h, ethanolamine incorporation into phosphatidyl ethanolamine was significantly less in blue than in white areas.

[1,2-¹⁴C]Choline incorporation into total lipid was linear for 3 h of incubation in blue areas but not in white areas. At 30 min, choline incorporation into phosphatidyl choline was significantly less in blue than in white areas; at 1 h choline incorporation into phosphatidyl choline was similar in blue and white areas, while after 3 h of incubation incorporation was significantly greater in blue than in white areas.

With both [2-¹⁴C]ethanolamine and [1,2-¹⁴C]choline, the percentage distribution of label among individual phospholipids was similar in blue and white areas.

Phospholipid content of blue and white areas was similar.

The results presented demonstrate further focal metabolic differences within the same geographical region of the normal young pig aorta.     

Intestinal microbial metabolism of phosphatidylcholine: a novel insight in the cardiovascular risk scenario

Intestinal microbiota is a “dynamic organ” influencing host metabolism, nutrition, physiology and immune system. Among its several interactions, the role of a phosphatidylcholine metabolite derived by gut flora activity, i.e., trimethylamine-N-oxide (TMAO), allows perceiving a novel insight in the cardiovascular risk scenario, being a strong predictor of this condition. Based on current reports, including the paper of Tang et al., we describe here: the possible role of intestinal microbiota in cardiovascular risk as well as potential interventions to reduce gut flora TMAO production by diet, probiotics and antibiotics. Finally, we highlight the possibility of evaluating, monitoring and modulating TMAO in order to use its serum levels as a marker of cardiovascular risk in the next future, when the need of controlled studies on large series will be satisfied.     

多烯磷脂酰胆碱联合二甲双胍治疗非酒精性脂肪性肝病患者疗效和安全性Meta分析

目的 系统评价应用多烯磷脂酰胆碱联合二甲双胍治疗非酒精性脂肪性肝病(NAFLD)患者的疗效和安全性。方法 全面检索知网(CNKI)、万方(WanFang Data)、维普(VIP)、EMbase、PubMed数据库,检索2018年8月前关于应用多烯磷脂酰胆碱联合二甲双胍治疗NAFLD患者的随机对照试验(RCT)研究,采用 RevMan 5.3 处理软件进行Meta 分析。结果 纳入18项RCT研究包括1596例患者,其中试验组803例,对照组793例。给予试验组患者多烯磷脂酰胆碱联合二甲双胍治疗,给予对照组其它药物治疗。Meta分析结果显示,试验组在降低胰岛素抵抗指数(HOMA-IR)、空腹血糖(FPG)、AST水平、ALT水平、GGT水平、LDL-C水平、TC水平、TG水平和提高HDL-C水平、超声检查指标改善率和肝/脾CT值比值方面优于对照组,差异有统计学意义(P＜0.05);两组在降低空腹胰岛素(FINS)水平和不良反应发生率方面差异无统计学意义(P＞0.05)。结论 应用多烯磷脂酰胆碱联合二甲双胍治疗NAFLD患者疗效较好,无明显不良反应。由于纳入研究的整体质量不高,仍需多中心和高质量的随机对照试验加以验证。     

多烯磷脂酰胆碱联合双环醇治疗胃癌化疗导致的药物性肝损伤患者疗效及其对血清细胞因子和氧化应激指标水平的影响

目的 探讨应用多烯磷脂酰胆碱联合双环醇治疗胃癌化疗所致的药物性肝损伤(DILI)患者疗效及其对血清细胞因子和氧化应激指标的影响。方法 2017年5月～2019年5月我院收治的胃癌根治术后患者78例,给予奥沙利铂、多西他赛和氟尿嘧啶化疗。在化疗过程中出现DILI患者40例,被随机分为对照组(n=19)和观察组(n=21),给予对照组患者多烯磷脂酰胆碱治疗,给予观察组多烯磷脂酰胆碱联合双环醇片治疗,两组均观察4周。采用ELISA法检测血清肿瘤坏死因子-α(TNF-α)和白细胞介素-6(IL-6),采用硫代巴比妥酸法检测血清丙二醛(MDA),采用黄嘌呤氧化法检测血清超氧化物歧化酶(SOD)。采用卡氏功能状态(KPS)量表评估患者生存质量。结果 在治疗4周末,观察组血清丙氨酸氨基转移酶(ALT)水平为(33.5±7.9)U/L,显著低于对照组【(42.4±8.8)U/L,P<0.05】,血清天冬氨酸氨基转移酶(AST)水平为(34.4±5.7)U/L,显著低于对照组【(39.4±6.2)U/L,P<0.05】,血清碱性磷酸酶(ALP)水平为(60.6±14.2)U/L,显著低于对照组【(75.3±16.6)U/L,P<0.05】,而KPS评分为(64.1±17.2)分,显著高于对照组【(48.3±14.5)分,P<0.05】;联合组肝功能复常率为81.0%,显著高于对照组的63.2%(P<0.05);观察组血清TNF-α水平为(15.2±2.1)mg/L,显著低于对照组【(21.4±3.6)mg/L,P<0.05】,血清IL-6水平为(28.1±4.5)pg/mL,显著低于对照组【(46.2±5.9)pg/mL,P<0.05】;血清MDA水平为(5.1±0.8)nmol/mL,显著低于对照组【(5.9±0.7)nmol/mL,P<0.05】,而血清SOD水平为(2.3±0.5)U/mL,显著高于对照组【(1.8±0.4)U/mL,P<0.05】。结论 联合应用多烯磷脂酰胆碱和双环醇片治疗化疗药导致的DILI患者能改善肝功能,可能与抑制了氧化应激反应,降低了血清细胞因子水平有关,值得进一步研究。     

A C-terminal truncated mutation of licC attenuates the virulence of Streptococcus pneumoniae

LicC has been identified as a virulence factor of Streptococcus pneumoniae. However, its role in virulence is still not fully understood because deletion of licC is lethal for the bacterium. In this study, a mutant with 78-bp truncation at the C-terminus of licC was obtained from a signature-tagged mutagenesis (STM) library. The mutant was viable with a large reduction in enzymatic activity as CTP:phosphocholine cytidylyltransferase detected in vitro using a firefly luciferase assay. The mutation attenuated the adhesion and invasion of S. pneumoniae ST556 (serotype 19F) to epithelial cells by 72% and 80%, respectively, and increased the phagocytosis by macrophages for 16.5%, compared to the parental strain. When the mutation was introduced into the encapsulated D39 strain (serotype 2), it led to attenuated virulence in mouse models either by intranasal colonization or by intraperitoneal infection. In addition, the phosphocholine (PCho) on cell surface was decreased, and the choline binding proteins (CBPs) were impaired, which may explain the attenuated virulence of the mutant. These observations indicate that C-terminus of licC is accounted for the main activity of LicC in PCho metabolism and is essential for the virulence of S. pneumoniae, which provides a novel target for drug design against pneumococcal infection.     

Imaging Neuroinflammation? A Perspective from MR Spectroscopy

Neuroinflammatory mechanisms contribute to the brain pathology resulting from human immunodeficiency virus (HIV) infection. Magnetic resonance spectroscopy (MRS) has been touted as a suitable method for discriminating in vivo markers of neuroinflammation. The present MRS study was conducted in four groups: alcohol dependent (A, n = 37), HIV‐infected (H, n = 33), alcohol dependent + HIV infected (HA, n = 38) and healthy control (C, n = 62) individuals to determine whether metabolites would change in a pattern reflecting neuroinflammation. Significant four‐group comparisons were evident only for striatal choline‐containing compounds (Cho) and myo‐inositol (mI), which follow‐up analysis demonstrated were due to higher levels in HA compared with C individuals. To explore the potential relevance of elevated Cho and mI, correlations between blood markers, medication status and alcohol consumption were evaluated in H + HA subjects. Having an acquired immune deficiency syndrome (AIDS)‐defining event or hepatitis C was associated with higher Cho; lower Cho levels, however, were associated with low thiamine levels and with highly active antiretroviral HIV treatment (HAART). Higher levels of mI were related to greater lifetime alcohol consumed, whereas HAART was associated with lower mI levels. The current results suggest that competing mechanisms can influence in vivo Cho and mI levels, and that elevations in these metabolites cannot necessarily be interpreted as reflecting a single underlying mechanism, including neuroinflammation.     

Arachidyl amido cholanoic acid improves liver glucose and lipid homeostasis in nonalcoholic steatohepatitis via AMPK and mTOR regulation

BACKGROUND Arachidyl amido cholanoic acid(Aramchol) is a potent downregulator of hepatic stearoyl-CoA desaturase 1(SCD1) protein expression that reduces liver triglycerides and fibrosis in animal models of steatohepatitis. In a phase IIb clinical trial in patients with nonalcoholic steatohepatitis(NASH), 52 wk of treatment with Aramchol reduced blood levels of glycated hemoglobin A1c, an indicator of glycemic control.AIM To assess lipid and glucose metabolism in mouse hepatocytes and in a NASH mouse model [induced with a 0.1% methionine and choline deficient diet(0.1 MCD)] after treatment with Aramchol.METHODS Isolated primary mouse hepatocytes were incubated with 20 μmol/L Aramchol or vehicle for 48 h. Subsequently, analyses were performed including Western blot, proteomics by mass spectrometry, and fluxomic analysis with ~(13)C-uniformly labeled glucose. For the in vivo part of the study, male C57 BL/6 J mice were randomly fed a control or 0.1 MCD for 4 wk and received 1 or 5 mg/kg/d Aramchol or vehicle by intragastric gavage for the last 2 wk. Liver metabolomics were assessed using ultra-high-performance liquid chromatography-time of flight-MS for the determination of glucose metabolism-related metabolites.RESULTS Combination of proteomics and Western blot analyses showed increased AMPK activity while the activity of nutrient sensor mTORC1 was decreased by Aramchol in hepatocytes. This translated into changes in the content of their downstream targets including proteins involved in fatty acid(FA) synthesis and oxidation [PACCα/β(S79), SCD1, CPT1A/B, HADHA, and HADHB], oxidative phosphorylation(NDUFA9, NDUFB11, NDUFS1, NDUFV1, ETFDH, and UQCRC2), tricarboxylic acid(TCA) cycle(MDH2, SUCLA2, and SUCLG2), and ribosome(P-p70S6K[T389] and P-S6[S235/S236]). Flux experiments with ~(13)C uniformely labeled glucose showed that TCA cycle cataplerosis was reduced by Aramchol in hepatocytes, as indicated by the increase in the number of rounds that malate remained in the TCA cycle. Finally, liver metabolomic analysis showed that glucose homeostasis was improved by Aramchol in 0.1 MCD fed mice in a dose-dependent manner, showing normalization of glucose, G6P, F6P, UDP-glucose, and Rbl5 P/Xyl5 P.CONCLUSION Aramchol exerts its effect on glucose and lipid metabolism in NASH through activation of AMPK and inhibition of mTORC1, which in turn activate FA β-oxidation and oxidative phosphorylation.     

Archaebiotics

Trimethylamine (TMA) is produced by gut bacteria from dietary ingredients. In individuals with a hereditary defect in flavin-containing monooxygenase 3, bacterial TMA production is believed to contribute to the symptoms of trimethylaminuria (TMAU; fish-odor syndrome). Intestinal microbiota TMA metabolism may also modulate atherosclerosis risk by affecting trimethylamine oxide (TMAO) production levels. We propose that reducing TMA formation in the gut by converting it to an inert molecule could be used to prevent or limit these human diseases, while avoiding the major drawbacks of other clinical interventions. Reducing TMA levels by microbiological interventions could also be helpful in some vaginoses. Particular members of a recently discovered group of methanogens, that are variably present in the human gut, are unusual in being apparently restricted to utilizing only methyl compounds including TMA as substrates. We confirmed experimentally that one of these strains tested, Methanomassiliicoccus luminyensis B10, is able to deplete TMA, by reducing it with H₂ for methanogenesis. We therefore suggest that members of this archaeal lineage could be used as treatments for metabolic disorders.     

Maternal choline supplementation differentially alters the basal forebrain cholinergic system of young‐adult Ts65Dn and disomic mice

Down syndrome (DS), trisomy 21, is a multifaceted condition marked by intellectual disability and early presentation of Alzheimer's disease (AD) neuropathological lesions including degeneration of the basal forebrain cholinergic neuron (BFCN) system. Although DS is diagnosable during gestation, there is no treatment option for expectant mothers or DS individuals. Using the Ts65Dn mouse model of DS that displays age‐related degeneration of the BFCN system, we investigated the effects of maternal choline supplementation on the BFCN system in adult Ts65Dn mice and disomic (2N) littermates at 4.3–7.5 months of age. Ts65Dn dams were maintained on a choline‐supplemented diet (5.1 g/kg choline chloride) or a control, unsupplemented diet with adequate amounts of choline (1 g/kg choline chloride) from conception until weaning of offspring; post weaning, offspring were fed the control diet. Mice were transcardially perfused with paraformaldehyde, and brains were sectioned and immunolabeled for choline acetyltransferase (ChAT) or p75‐neurotrophin receptor (p75^NTR). BFCN number and size, the area of the regions, and the intensity of hippocampal labeling were determined. Ts65Dn‐unsupplemented mice displayed region‐ and immunolabel‐dependent increased BFCN number, larger areas, smaller BFCNs, and overall increased hippocampal ChAT intensity compared with 2N unsupplemented mice. These effects were partially normalized by maternal choline supplementation. Taken together, the results suggest a developmental imbalance in the Ts65Dn BFCN system. Early maternal‐diet choline supplementation attenuates some of the genotype‐dependent alterations in the BFCN system, suggesting this naturally occurring nutrient as a treatment option for pregnant mothers with knowledge that their offspring is trisomy 21. J. Comp. Neurol. 522:1390–1410, 2014. © 2013 Wiley Periodicals, Inc.