Phosphatidylethanolamine N-methyltransferase and choline dehydrogenase gene polymorphisms are associated with human sperm concentration

Choline is a crucial factor in the regulation of sperm membrane structure and fluidity, and this nutrient plays an important role in the maturation and fertilizing capacity of spermatozoa. Transcripts of phosphatidylethanolamine N-methyltransferase （PEMT） and choline dehydrogenase （CHDH）, two basic enzymes of choline metabolism, have been observed in the human testis, demonstrating their gene expression in this tissue. In the present study, we explored the contribution of the PEMTand CHDHgene variants to sperm parameters. Two hundred oligospermic and 250 normozoospermic men were recruited. DNA was extracted from the spermatozoa, and the PEMT -774G〉C and CHDH ＋432G〉T polymorphisms were genotyped. The genotype distribution of the PEMT-774G〉C polymorphism did not differ between oligospermic and normozoospermic men. In contrast, in the case of the CHDH ＋432G〉T polymorphism, oligospermic men presented the CHDH432GIG genotype more frequently than normozoospermic men （62% vs. 42%, P〈0.001）. The PEMT774GIG genotype was associated with a higher sperm concentration compared to the PEMT774GIC and 774C/C genotypes in oligospermic men （12.5±5.6× 10^6 spermatozoa m1-1 vs. 8.3±5.2×10^6 spermatozoa m1-1, P〈0.002） and normozoospermic men （81.5±55.6×10^6 vs. 68.1±44.5×10^6 spermatozoa m1-1, P〈0.006）. In addition, the CHDH432G/G genotype was associated with higher sperm concentration compared to CHDH432G.T and 432T/T genotypes in oligospermic （11.8±5.1×10^6 vs. 7.8±5.3×10^6 spermatozoa m1-1, P〈0.003） and normozoospermic men （98.6±62.2×10^6 vs. 58.8±＋33.6×10^6 spermatozoa m1-1, P〉0.001）. In our series, the PEMT-774G〈C and CHDH ＋432G〈T polymorphisms were associated with sperm concentration. This finding suggests a possible influence of these genes on sperm quality.

Exogenous phosphatidylethanolamine induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway

AIM: To investigate the signaling pathways implicated in phosphatidylethanolamine (PE)-induced apoptosis of human hepatoma HepG2 cells. METHODS: Inhibitory effects of PE on human hepatoma HepG2 cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle, apoptosis and mitochondrial transmembrane potential (ΔΨm) were analyzed by flow cytometry. Immunocytochemical assay and Western blotting were used to examine Bcl-2, Bax and caspase-3 protein levels in HepG2 cells treated with PE. RESULTS: PE inhibited the growth of HepG2 cells in a doseand timedependent manner. It did notaffect the cell cycle, but induced apoptosis. PE significantly decreased ΔΨm at 0.25, 0.5 and 1 mmol/L, respectively, suggesting that PE induces cell apoptosis by decreasing the mitochondrial transmembrane potential. The Bcl-2 expression level induced by different concentrations of PE was lower than that in control groups. However, the Bax expression level induced by PE was higher than that in the control group. Meanwhile, PE increased the caspase-3 expression in a doseand time-dependent manner. CONCLUSION: Exogenous PE induces apoptosis of human hepatoma HepG2 cells via the bcl-2/bax pathway.

Phosphatidylethanolamine functionalized biomimetic monolith for immobilized artificial membrane chromatography

In this research,a new phospholipid based monolith was fabricated by in situ co-polymerization of 1-dodecanoyl-2-(11-methacrylamidoundecanoyl)-sn-glycero-3-phosphoethanolamine and ethylene dimethacrylate to mimick bio-membrane environment.Excellent physicochemical properties of this novel monolith that were achieved included column efficiency,stability,and permeability.Moreover,the biomimetic monolith showed outstanding separation capability for a series of intact proteins and small molecules.In particular,it exhibited good potential as an alternative to the commercial immobilized artificial membrane(IAM)column(IAM.PC.DD2)for studying drug-membrane interactions.This study not only enriched the types of IAM stationary phases,but also provided a simple model for the prediction of phosphatidylethanolamine related properties of drug candidates.

Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene

AIM： To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis （UC） and the clinical course of these patients. METHODS： A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase （HNMT） and diamine oxidase （ABP1） enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years （mean time 11 years）. RESULTS： There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR （95% CI） for variant alleles = 1.22 （0.91-1.61）]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR （95 % CI） for carriers of mutated alleles 2.41 （1.21-4.83; P=0.006）], with a significant gene-dose effect （P= 0.0038）. In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients,regardless clinical evolution, and control individuals. CONCLUSION： The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.

A Comparative Study About the Neuroprotective Effects of EPA-Enriched Phosphoethanolamine Plasmalogen and Phosphatidylethanolamine Against Oxidative Damage in Primary Hippocampal Neurons

s Oxidative stress is involved in the progression of neurodegenerative diseases.Previous evidences showed that plasma-logens could improve neurodegenerative diseases.In this study,we investigated the function of phosphoethanolamine plasmalogens enriched with EPA(EPA-pPE)and phosphatidylethanolamine enriched with EPA(EPA-PE)on oxidative damage prevention after hy-drogen peroxide(H2O2)and tert-butylhydroperoxide(t-BHP)challenge in primary hippocampal neurons.Results showed that neurons pretreated with EPA-pPE and EPA-PE demonstrated the ability to alleviate oxidative damage,which was proved by the in-creased cell viability.Moreover,the shape and number of neurons were more similar to those of the control group.Antioxidant acti-vity,apoptosis,as well as TrkB/ERK/CREB signaling pathway were investigated to explore the mechanisms.The results suggested that EPA-PE was superior to EPA-pPE in regulating mitochondrial apoptosis.EPA-pPE was more prominent than EPA-PE in upre-gulating TrkB/ERK/CREB signaling pathway.Phospholipids with EPA exerted neuroprotective effects via inhibiting oxidative stress,suppressing apoptosis,and regulating TrkB/ERK/CREB signaling pathway.Therefore,the results provide a scientific basis for utili-zation of phospholipids enriched with EPA on the treatment of neurodegenerative disease.

磷脂酰乙醇胺-还原糖美拉德产物的制备及抗氧化活性研究

为研究亚麻籽炒籽过程中形成的美拉德产物(MRPs)以及提高低温压榨亚麻籽油的氧化稳定性,将3种还原糖(葡萄糖、果糖和木糖)与磷脂酰乙醇胺(PE)进行模拟反应,探究反应温度、反应时间和底物物质的量比对MRPs抗氧化活性的影响,利用质谱分析MRPs的主要成分,并考察MRPs对低温压榨亚麻籽油氧化稳定性和醛类化合物形成的影响。结果表明:PE-木糖体系的MRPs具有最高的体外抗氧化能力,其最适反应条件为PE与木糖物质的量比1∶1、反应温度160℃、反应时间60 min,在该条件下MRPs(2 mg/mL)DPPH自由基清除率达79.57%,铁离子还原抗氧化能力(FRAP)为43.65μmol/g,铁离子螯合能力为13.34%;通过质谱分析发现由一分子木糖和一分子PE反应形成的PE-吡咯-2-甲醛为MRPs中的主要成分;在190℃加速氧化实验中,PE-木糖体系的MRPs对低温压榨亚麻籽油过氧化值和p-茴香胺值的增长表现出与TBHQ相似的抑制作用,同时核磁共振氢谱分析结果表明MRPs可以减缓单烯醛和二烯醛的生成。综上,MRPs可以有效提高油脂的氧化稳定性。

石榴花水提物调节AHR/BNIP3改善糖尿病小鼠肝脏胰岛素信号

目的:探讨石榴花水提物(pomegranate flower water extract,PFW)对2型糖尿病小鼠肝脏胰岛素信号传导的影响及机制。方法:将C57BL/6J随机分为正常组、模型组、二甲双胍组(Met)、石榴花水提物低剂量组(PFWL)和石榴花水提物高剂量组(PFWH)。连续给药11周后,称小鼠体质量,检测空腹血糖(FBG)、胰岛素(INS)、甘油三酯(TG)和总胆固醇(TC)的含量,计算胰岛素抵抗指数(HOMA-IR);苏木素-伊红(HE)染色观察肝组织病理变化;Western blot法检测肝组织中胰岛素受体底物1(IRS1)、p-IRS1(Ser307)、蛋白激酶B(AKT)、p-AKT(Ser473)、糖原合成酶激酶-3β(Gsk3β)、p-Gsk3β(S9)、芳香烃受体(AhR)、磷脂酰乙醇胺N-甲基转移酶(PEMT)、Bcl-2/腺病毒E1B-19kDa相互作用蛋白3(BNIP3)蛋白表达。结果:与模型组比较,PFWH组FBG、INS、HOMA-IR、TG和TC含量极显著降低(P<0.01);PFWH组小鼠肝细胞内脂肪滴明显减少;PFWH组极显著升高肝脏中IRS1、p-AKT(Ser473)/AKT、p-Gsk3β(S9)/Gsk3β、BNIP3蛋白表达(P<0.01),极显著降低p-IRS1(Ser307)/IRS1、AHR、PEMT蛋白表达(P<0.01)。结论:PFW可能通过调节AHR/BNIP3抑制肝脏脂质沉积,改善p-IRS1(Ser307)/p-AKT(Ser473)/p-GSK3β(S9)胰岛素信号通路转导。

基于脂质组学分析揭示高原低氧对小鼠脾组织磷脂代谢的调控机制

脾是机体最大的淋巴器官,参与病原体清除和抗体产生的免疫反应过程,并参与代谢平衡调节。高原低氧环境可影响脾组织脂质代谢,但影响脂质代谢的关键机制仍不清楚。我们旨在使用脂质组学分析方法研究高原低氧对小鼠脾组织脂质代谢的影响。将C57BL/6小鼠分别置于海拔4200 m(高原低氧组,HST组)和400 m(平原常氧组,PSC组),30 d取脾组织。使用超高效液相色谱-Orbitrap质谱系统进行脂质组学分析。30 d时在高原低氧环境下,小鼠脾指数降低,并出现白髓减少,生发中心扩大,边缘模糊,静脉充血等病理学改变。脂质组学分析结果显示,共鉴定到41种脂质亚类和2473种脂质分子,甘油三酯(triacylglycerides,TGs)和磷脂酰胆碱(phosphatidylcholines,PCs)为脂质分子鉴别到最多的2种。使用单变量和多变量分析,鉴定到44个差异脂质分子,它们主要集中于磷脂代谢。随后,对磷脂代谢途径中的关键酶进行RT-qPCR检测,发现其mRNA表达量均有差异(P<0.05)。提示高原低氧环境主要影响小鼠脾组织磷脂代谢,并通过减少PC和磷脂酸(phosphatidic acid,PA)含量,促进其转化为磷脂酰乙醇胺(phosphatidylethanolamine,PE)和心磷脂(cardiolipin,CL)并通过CDP-乙醇胺(CDP-Ethanolamine,CDP-Etn)途径促进PE生成。该研究为高原低氧环境下脾组织中磷脂代谢异常提供新的实验依据。

SREBP2、LOXL2和PEBP4在原发性肝癌中的表达及与患者临床病理特征的相关性

目的 探讨胆固醇调节元件结合蛋白2(SREBP2)、赖氨酰氧化酶样蛋白2(LOXL2)和磷脂酰乙醇胺结合蛋白4(PEBP4)在原发性肝癌(以下简称肝癌)中的表达及与患者临床病理特征的相关性。方法 选择2016年1月至2019年12月在廊坊市第四人民医院接受手术治疗的72例原发性肝癌患者作为研究对象,收集其临床资料。采用实时荧光定量PCR法检测组织中SREBP2、LOXL2和PEBP4的mRNA表达水平,分析肝癌组织中SREBP2、LOXL2和PEBP4的mRNA表达与患者临床病理特征及血管生成拟态(VM)的相关性,并分析肝癌组织中不同SREBP2、LOXL2和PEBP4 mRNA表达的患者的生存情况。结果 肝癌组织中SREBP2、LOXL2和PEBP4的mRNA表达水平均较癌旁组织显著升高(P均<0.05)。肝癌组织中SREBP2、LOXL2和PEBP4的m RNA表达与患者的TNM分期、病理分级、脉管侵犯均有相关性(P均<0.05)。72例患者的肝癌组织中有27例(37.50%)VM形成,VM染色阳性的肝癌组织中SREBP2、LOXL2和PEBP4的mRNA表达水平均显著高于VM染色阴性的肝癌组织(P均<0.05)。多因素logistic回归分析结果显示肝癌组织中SREBP2、LOXL2和PEBP4的mRNA高表达均为VM的危险因素(P均<0.05)。Kaplan-Meier生存分析结果显示,肝癌组织中SREBP2、LOXL2和PEBP4 mRNA高表达者的3年总生存率均较低表达者显著降低(P均<0.05)。结论 肝癌组织中SREBP2、LOXL2和PEBP4的m RNA均呈高表达,且与患者的部分临床病理特征、肝癌细胞VM形成均相关,并可影响预后。

低碳醇对大豆磷脂中磷脂酰胆碱和磷脂酰乙醇胺的选择性研究

研究了低碳醇对磷脂酰胆碱和磷脂酰乙醇胺的选择性 ,指出低温、低乙醇浓度有利于对磷脂酰胆碱的选择性。

柱色谱法制备高纯大豆卵磷脂和脑磷脂研究

以大豆油脚为原料 ,采用溶剂萃取法和柱色谱法相结合的工艺制备高纯卵磷脂和脑磷脂 ,研究了不同洗脱剂及不同洗脱模式对卵磷脂和脑磷脂柱色谱分离效果的影响。实验结果表明 :大豆油脚先经脱水、脱油 ,再经 95 %乙醇浸提后粗分为粗卵磷脂和粗脑磷脂 ,以硅胶为吸附介质 ,分别进行柱色谱分离。粗卵磷脂为原料用无水甲醇作为洗脱剂等度淋洗 ,可获得大量相对含量为91.9%的卵磷脂和少量含量为 74 .2 %的脑磷脂产品 ;粗脑磷脂为原料用氯仿 -甲醇 ( 2∶1,V/V)、无水甲醇的梯度淋洗模式 ,可获得少量含量 96 .7%的高纯卵磷脂和大量含量 82 .1%的脑磷脂产品。

HPLC与MALDI-TOFMS联用技术分析蛋黄中的磷脂

蛋黄中含有大量磷脂,其中磷脂酰胆碱(PC)和磷脂酰乙醇胺(PE)最为丰富。本研究采用高效液相色谱法(HPLC)与基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)联用技术分析了蛋黄中磷脂粗提物。将从蛋黄中提取的多种磷脂通过HPLC预先分离,收集各组分后分别进行MALDI-TOF MS分析得到比较清晰的质谱图。通过质谱图解析确定了蛋黄中磷脂酰胆碱、神经鞘磷脂(SM)的脂肪酸组成。

植物FLOWERING LOCUS T/TERMINAL FLOWER1基因家族的研究进展

植物FLOWERING LOCUS T/TERMINAL FLOWER1(FT/TFL1)基因家族是一个进化上高度保守的基因家族,它在植物的花发育过程中具有重要作用:其成员FT基因编码的蛋白产物是可以长距离转运的成花激素,在花形成过程中起关键作用;另一成员TFL1基因则在花序的形成和维持过程中起重要作用.本文就近年来国内外对植物FT/TFL1基因家族的结构、成员,以及各个成员在花发育转换过程中的功能等研究现状进行综述,并对该基因家族的研究前景提出展望.

磷脂酰乙醇胺的酶促合成及底物抑制动力学

对磷脂酶D(phospholipase D,PLD)在有机溶媒-水两相体系中催化磷脂酰胆碱(phosphatidylcholine,PC)和乙醇胺(ethanolamine,EA)合成磷脂酰乙醇胺(phosphatidylethanolamine,PE)的反应条件进行优化,并对反应动力学机制进行了研究。确定最佳反应条件为:温度28℃,p H 5.5,底物摩尔比(EA/PC)20∶1,在此条件下PE产率达87.2%。通过研究底物浓度对反应速率的影响,确定反应符合单底物抑制的Ping-Pang机制。分别以Matlab软件的Fminsearch函数与Lineweaver-Burk双倒数作图法求取动力学参数,结果基本一致,底物乙醇胺EA的抑制常数为Ki B=1.50mmol/L。抑制机理为两分子EA同时结合到一分子磷脂酰基-PLD中间体上,生成磷脂酰基-PLD-(EA)2死端复合物,符合竞争性抑制反应动力学规律。该动力学模型预测与实验数据吻合良好,对PLD催化合成PE反应过程的操作及反应器选型设计具有指导作用。

STAT1和STAT2在磷脂酰乙醇胺诱导肝癌HepG2细胞生长抑制中的作用

目的探讨磷脂酰乙醇胺(PE)诱导肝癌HepG2细胞生长抑制中STAT1和STAT2的作用。方法实验以人肝癌细胞系HepG2为材料,分别设置了空白对照组、0.125、0.25、0.5和1 mmol/L PE处理组。应用MTT法检测细胞生长,荧光免疫组化检测细胞内STAT1和STAT2表达。结果与对照组相比,PE各处理组对HepG2细胞生长的抑制作用具有剂量依赖性,并可诱导STAT1和STAT2高表达,而AG490可以部分逆转PE的效应。结论 STAT1和STAT2参与了PE诱导HepG2细胞的生长抑制过程。

菜籽油脚中脑磷脂的提取与纯化工艺研究

以菜籽油脚为原料,采用溶剂分提法与柱色谱分离法相结合的工艺制备高纯度脑磷脂(PE)。通过正交试验得出最佳的溶剂分提工艺参数为:分提时间20 m in,粉末磷脂与95%乙醇溶剂比1∶7,分提次数3次,分提温度40℃。在此条件下所得产物中PE含量为46.3%。采用硅胶为固定相的柱色谱分离技术对溶剂分提产物进行进一步纯化,试验结果表明:控制洗脱流速为3 mL/m in,进样量为1.5 g(100 g硅胶),氯仿-甲醇(体积比2∶1)为洗脱剂的条件下分离效果较好,所得PE产品的纯度为94.5%,回收率为85.1%。

磷酯酰乙醇胺与硬脂酸和十八醇二元混合体系单层膜的热力学特性和AFM观测

利用表面压力-平均分子面积(π-A)曲线的关系,分别研究了在水/空气界面上形成的磷酯酰乙醇胺(PE)与硬脂酸(SA)和十八醇(OD)二元混合体系的热力学特性.根据对弹性模量(CS-1)、过量分子面积(Aex)以及表面过量吉布斯自由能(ΔGex)等热力学参数的数据计算,定量分析了混合单层膜分子之间的相互作用.实验结果表明,PE/SA和PE/OD单层膜两种组分之间摩尔比对其热力学参数有影响.热力学分析表明,在XSA=0.2,0.8和XOD=0.8处,PE/SA和PE/OD二元混合体系的热力学参数[过量分子面积(Aex)和表面过量吉布斯自由能(ΔGex)]相对理想状态均表现为负偏差作用,说明分子之间的作用为引力作用.相反,PE/OD二元体系在XOD=0.2,0.4,0.6处,表现为正偏差作用,这说明分子之间的作用为斥力作用.AFM观测为PE/SA和PE/OD单层膜热力学特性的理论分析提供了有力的支持.

PEBP在切割穹窿海马伞大鼠海马中的表达变化

切割大鼠右侧穹窿海马伞,应用Western blot、免疫组化技术,观察切割后海马中磷脂酰乙醇胺结合蛋白(phosphatidyle-thanolamine binding protein,PEBP)的表达的时空变化。Western blot结果显示:PEBP在切割后3 d表达开始上升,7 d达最高水平,随后缓慢下降,28 d时降至正常。免疫组化结果显示:术后各时间点切割侧海马CA1～CA3区的锥体细胞层和齿状回颗粒层的PEBP阳性细胞数与正常侧相比无显著性差异(P>0.05),但切割侧PEBP阳性细胞染色加深,7 d时最为明显,两侧比较灰度值有显著性差异(P<0.01)。切割侧齿状回门区和颗粒下层中可见较多深染的PEBP阳性细胞,其细胞数和灰度值与正常侧相比均有显著性差异(P<0.05)。结合本课题组以往的工作,本结果提示切割穹窿海马伞后PEBP的高表达可能与海马神经再生有关。

柱层析法分离大豆磷脂

通过实验探讨了使用低压制备色谱柱在等度洗脱方式下分离大豆磷脂中的磷脂酰肌醇(PI)、磷脂酰乙醇胺 (PE)、磷脂酰胆碱 (PC)等成分。结果表明 ,在使用 10 0cm× 2 6mm规格的色谱柱、氯仿 -甲醇 (2∶1)作为流动相、流速控制在 3 0mL/min ,负载量为 0 .2 5g/ 15 0g硅胶 (10 0～ 2 0 0目 )的条件下可以分离得到PI纯度在 90 %以上、PE纯度在 80 %以上、PC纯度在 95 %以上的各种产品。

甲氧基聚乙二醇-磷脂酰乙醇胺的制备及其对脂质体的稳定作用

采用两步反应法制备脂质体空间稳定膜材料甲氧基聚乙二醇 -磷脂酰乙醇胺 (MPEG- EPE) ,并用以制备空间稳定脂质体 (SL s) ,同时制备不含 MPEG- EPE的传统脂质体 (CL s) ,比较两者放置过程中粒径变化、加乙醇后浊度变化、包封钙黄绿素后在冻干 -再水化过程中的荧光泄漏程度及其与人血浆蛋白的吸附指标 ,评价 MPEG2 0 0 0 - EPE对脂质体的稳定作用。结果表明 ,试验前后 SL s的粒径及浊度变化不大 ,荧光泄漏程度和人血浆蛋白吸附量也远小于 CL s,提示其对脂质体有良好的稳定作用。