Met, methionine

Met,蛋氨酸
  • 文章类型: Journal Article
    短链脂肪酸(SCFA)在结肠癌的细胞和动物模型中表现出抗癌活性。醋酸盐,丙酸盐,和丁酸盐是由膳食纤维通过肠道微生物群发酵产生的三种主要SCFA,对人体健康具有有益作用。以往对SCFA抗肿瘤机制的研究大多集中在参与抗肿瘤通路的特定代谢产物或基因上,如活性氧(ROS)生物合成。在这项研究中,我们对乙酸盐的影响进行了系统和无偏见的分析,丙酸盐,和丁酸盐对人结肠直肠腺癌细胞生理浓度下ROS水平以及代谢和转录组特征的影响。我们观察到在处理的细胞中ROS水平显著升高。此外,显著调节的信号涉及代谢和转录组水平的重叠途径,包括ROS反应和代谢,脂肪酸运输和代谢,葡萄糖反应和代谢,线粒体运输和呼吸链复合物,一碳代谢,氨基酸运输和代谢,和谷氨酰胺分解,它们与ROS的产生直接或间接相关。此外,代谢和转录组调节以SCFAs类型依赖的方式发生,从乙酸到丙酸再到丁酸的程度逐渐增加。本研究全面分析了SCFA如何诱导ROS产生并调节结肠癌细胞的代谢和转录水平。这对于理解SCFA对结肠癌抗肿瘤活性的作用机制至关重要。
    Short-chain fatty acids (SCFAs) exhibit anticancer activity in cellular and animal models of colon cancer. Acetate, propionate, and butyrate are the three major SCFAs produced from dietary fiber by gut microbiota fermentation and have beneficial effects on human health. Most previous studies on the antitumor mechanisms of SCFAs have focused on specific metabolites or genes involved in antitumor pathways, such as reactive oxygen species (ROS) biosynthesis. In this study, we performed a systematic and unbiased analysis of the effects of acetate, propionate, and butyrate on ROS levels and metabolic and transcriptomic signatures at physiological concentrations in human colorectal adenocarcinoma cells. We observed significantly elevated levels of ROS in the treated cells. Furthermore, significantly regulated signatures were involved in overlapping pathways at metabolic and transcriptomic levels, including ROS response and metabolism, fatty acid transport and metabolism, glucose response and metabolism, mitochondrial transport and respiratory chain complex, one-carbon metabolism, amino acid transport and metabolism, and glutaminolysis, which are directly or indirectly linked to ROS production. Additionally, metabolic and transcriptomic regulation occurred in a SCFAs types-dependent manner, with an increasing degree from acetate to propionate and then to butyrate. This study provides a comprehensive analysis of how SCFAs induce ROS production and modulate metabolic and transcriptomic levels in colon cancer cells, which is vital for understanding the mechanisms of the effects of SCFAs on antitumor activity in colon cancer.
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  • 文章类型: Journal Article
    未经证实:缺乏对新型冠状病毒疾病的治疗导致寻找能够抑制病毒复制的特定抗病毒药物。植物界已被证明是具有抗病毒潜力的新分子的重要来源。
    UNASSIGNED:本研究旨在利用各种计算工具来鉴定最有资格的候选药物,这些候选药物具有通过抑制主要蛋白酶(Mpro)酶来阻止SARS-COV-2病毒复制的能力。
    未经证实:我们选择了提取物对先前发现的冠状病毒具有抑制潜力的植物。调查了它们的植物成分,并制备了100个分子的文库。然后,计算工具,如分子对接,利用ADMET和分子动力学模拟来筛选化合物并评估它们对Mpro酶的影响。
    未经鉴定:所有的植物成分都显示出对Mpro酶的良好结合亲和力。其中月桂碱具有最高的结合亲和力,即-294.1533kcal/mol。在ADMET分析中,模拟了1.2ns的最佳三种配体,然后将其中的稳定配体进一步模拟20ns。结果表明,在月桂碱w.r.t.蛋白质残基中未观察到构象变化,较低的RMSD值表明月桂碱-蛋白质复合物稳定20ns。
    未经批准:劳罗利辛,黑斑草根的活性成分,被发现具有良好的ADMET谱并且具有停止酶活性的能力。因此,这使得月桂碱成为治疗COVID-19的良好候选药物。
    UNASSIGNED: Lack of treatment of novel Coronavirus disease led to the search of specific antivirals that are capable to inhibit the replication of the virus. The plant kingdom has demonstrated to be an important source of new molecules with antiviral potential.
    UNASSIGNED: The present study aims to utilize various computational tools to identify the most eligible drug candidate that have capabilities to halt the replication of SARS-COV-2 virus by inhibiting Main protease (Mpro) enzyme.
    UNASSIGNED: We have selected plants whose extracts have inhibitory potential against previously discovered coronaviruses. Their phytoconstituents were surveyed and a library of 100 molecules was prepared. Then, computational tools such as molecular docking, ADMET and molecular dynamic simulations were utilized to screen the compounds and evaluate them against Mpro enzyme.
    UNASSIGNED: All the phytoconstituents showed good binding affinities towards Mpro enzyme. Among them laurolitsine possesses the highest binding affinity i.e. -294.1533 kcal/mol. On ADMET analysis of best three ligands were simulated for 1.2 ns, then the stable ligand among them was further simulated for 20 ns. Results revealed that no conformational changes were observed in the laurolitsine w.r.t. protein residues and low RMSD value suggested that the Laurolitsine-protein complex was stable for 20 ns.
    UNASSIGNED: Laurolitsine, an active constituent of roots of Lindera aggregata, was found to be having good ADMET profile and have capabilities to halt the activity of the enzyme. Therefore, this makes laurolitsine a good drug candidate for the treatment of COVID-19.
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  • 文章类型: Journal Article
    鱼藤酮是一种广谱农药,用于世界各地的各种农业实践。人类通过口服接触这种化学物质,鼻部,和真皮路线。鱼藤酮的吸入使肺的生物分子成分暴露于这种化学物质。肺的生物物理活动由肺表面活性剂精确调节以促进气体交换。表面活性蛋白(SP)是肺表面活性物质的基本成分。SP-A和SP-D等SP具有抗菌活性,可为肺部感染提供重要的第一道防线,而SP-B和SP-C主要参与呼吸循环和降低空气-水界面的表面张力。在这项研究中,使用AutoDockVina进行了分子对接分析,以研究鱼藤酮与四种SP的结合潜力。结果表明,鱼藤酮可以与SP-A的碳水化合物识别域(CRD)结合,N-,和SP-B的C末端肽,SP-C,和SP-D的CRD在多个位点通过几个相互作用介质如H键,C-H键,烷基键,pi-pi堆叠,范德华互动,和其他。鱼藤酮与SP的这种相互作用可以破坏肺中SP的生物物理和抗微生物功能,这可能会引起呼吸道疾病和病原体感染。
    Rotenone is a broad-spectrum pesticide employed in various agricultural practices all over the world. Human beings are exposed to this chemical through oral, nasal, and dermal routes. Inhalation of rotenone exposes bio-molecular components of lungs to this chemical. Biophysical activity of lungs is precisely regulated by pulmonary surfactant to facilitate gaseous exchange. Surfactant proteins (SPs) are the fundamental components of pulmonary surfactant. SPs like SP-A and SP-D have antimicrobial activities providing a crucial first line of defense against infections in lungs whereas SP-B and SP-C are mainly involved in respiratory cycle and reduction of surface tension at air-water interface. In this study, molecular docking analysis using AutoDock Vina has been conducted to investigate binding potential of rotenone with the four SPs. Results indicate that, rotenone can bind with carbohydrate recognition domain (CRD) of SP-A, N-, and C- terminal peptide of SP-B, SP-C, and CRD of SP-D at multiples sites via several interaction mediators such as H bonds, C-H bonds, alkyl bonds, pi-pi stacked, Van der Waals interaction, and other. Such interactions of rotenone with SPs can disrupt biophysical and anti-microbial functions of SPs in lungs that may invite respiratory ailments and pathogenic infections.
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  • 文章类型: Journal Article
    丙酸的先天错误,钴胺和蛋氨酸代谢是全球大多数计划中新生儿筛查(NBS)的目标,并且主要通过使用串联质谱(MS/MS)分析干血斑点(DBS)卡中的丙酰基肉碱(C3)和甲硫氨酸来筛选。单独使用C3和蛋氨酸的单层NBS方法缺乏特异性,如果采用保守的截止方法以最大程度地降低漏诊的风险,则可能导致假阳性率增加。实施2-甲基柠檬酸(MCA)的液相色谱串联质谱(LC-MS/MS)第二层测试,甲基丙二酸(MMA),来自同一DBS卡的同型半胱氨酸(HCY)可以通过降低假阳性率和消除重复样本收集的需要来提高疾病筛查性能。然而,MCA的DBS分析,MMA,由于有限的样品尺寸和分析物特性导致低MS/MS灵敏度和差的反相色谱保留的组合,通过LC-MS/MS和HCY是具有挑战性的。对于MCA,通过使用DAABD-AE的酰胺化以及通过MMA和HCY的丁基化可以实现足够的MS响应和分析性能。在这里,我们描述了第二层双衍生LC-MS/MS方法的验证,以检测升高的MCA,MMA,以及NBS的DBS卡中的HCY。通过对标本的回顾性分析证明了临床实用性,实验室间方法比较,和外部能力样本的评估。不精确度<10.8%CV,分析物回收率在90.2和109.4%之间。此第二层LC-MS/MS方法的工作流程和分析性能特征可在NBS实验室中实施。
    Inborn errors of propionate, cobalamin and methionine metabolism are targets for Newborn Screening (NBS) in most programs world-wide, and are primarily screened by analyzing for propionyl carnitine (C3) and methionine in dried blood spot (DBS) cards using tandem mass spectrometry (MS/MS). Single-tier NBS approaches using C3 and methionine alone lack specificity, which can lead to an increased false-positive rate if conservative cut-offs are applied to minimize the risk of missing cases. Implementation of liquid chromatography tandem mass spectrometry (LC-MS/MS) second-tier testing for 2-methylcitric acid (MCA), methylmalonic acid (MMA), and homocysteine (HCY) from the same DBS card can improve disease screening performance by reducing the false-positive rate and eliminating the need for repeat specimen collection. However, DBS analysis of MCA, MMA, and HCY by LC-MS/MS is challenging due to limited specimen size and analyte characteristics leading to a combination of low MS/MS sensitivity and poor reverse-phase chromatographic retention. Sufficient MS response and analytical performance can be achieved for MCA by amidation using DAABD-AE and by butylation for MMA and HCY. Herein we describe the validation of a second-tier dual derivatization LC-MS/MS approach to detect elevated MCA, MMA, and HCY in DBS cards for NBS. Clinical utility was demonstrated by retrospective analysis of specimens, an interlaboratory method comparison, and assessment of external proficiency samples. Imprecision was <10.8% CV, with analyte recoveries between 90.2 and 109.4%. Workflows and analytical performance characteristics of this second-tier LC-MS/MS approach are amenable to implementation in the NBS laboratory.
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  • 文章类型: Journal Article
    质膜转运蛋白在营养物质的导入中起着关键作用,包括糖,氨基酸,核碱基,羧酸,和金属离子,围绕真菌细胞。通过胞吞作用选择性去除这些转运蛋白是最重要的调节机制之一,可确保细胞快速适应不断变化的环境(例如,营养波动或不同的压力)。这种机制的核心是蛋白质网络,其中包括与抑制蛋白相关的运输衔接子(ART),该衔接子将泛素连接酶Rsp5与营养转运蛋白和内吞因子联系起来。转运蛋白构象变化,以及其胞质末端/环与质膜脂质之间的动态相互作用,在胞吞过程中也很关键。这里,我们回顾了有关营养转运蛋白内吞作用的分子机制的最新知识和最新发现,在酿酒酵母酵母和某些丝状真菌曲霉中。我们详细阐述了在自然界中发现的动态条件下,紧密调节的内吞作用对细胞适应性的生理重要性,并强调了对该过程的进一步理解和工程对于最大化滴度至关重要。工业生物技术过程中工程细胞工厂的速率和产量(TRY)值。
    Plasma membrane transporters play pivotal roles in the import of nutrients, including sugars, amino acids, nucleobases, carboxylic acids, and metal ions, that surround fungal cells. The selective removal of these transporters by endocytosis is one of the most important regulatory mechanisms that ensures a rapid adaptation of cells to the changing environment (e.g., nutrient fluctuations or different stresses). At the heart of this mechanism lies a network of proteins that includes the arrestin-related trafficking adaptors (ARTs) which link the ubiquitin ligase Rsp5 to nutrient transporters and endocytic factors. Transporter conformational changes, as well as dynamic interactions between its cytosolic termini/loops and with lipids of the plasma membrane, are also critical during the endocytic process. Here, we review the current knowledge and recent findings on the molecular mechanisms involved in nutrient transporter endocytosis, both in the budding yeast Saccharomyces cerevisiae and in some species of the filamentous fungus Aspergillus. We elaborate on the physiological importance of tightly regulated endocytosis for cellular fitness under dynamic conditions found in nature and highlight how further understanding and engineering of this process is essential to maximize titer, rate and yield (TRY)-values of engineered cell factories in industrial biotechnological processes.
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  • 文章类型: Journal Article
    由SARS-CoV-2引起的严重急性呼吸系统综合症(SARS)在全球范围内空前蔓延,这描绘了大流行对人类健康的痛苦后果。经济和生态系统服务。到目前为止,新型冠状病毒(CoV)的爆发与SARS-CoV-2(2019年)有关,中东呼吸综合征冠状病毒(MERS-CoV,2012),和SARS-CoV-1(2003)事件。CoV涉及具有正义单链RNA(+ssRNA)的有包膜Betacoronavirus(βCoV)家族。很清楚的坚持,传输,SARS-CoV-2通过近距离传播,粪便-口腔途径现已成为社区传播的主要环境问题。CoV在胃肠道(GI)中的复制和持久性以及通过粪便脱落表明了向环境设置的潜在传播途径。尽管有证据,基于关于SARS-CoV-2在废水/污水/水中的发生和持久性的报道较少,感染病毒向社区的传播尚未确定。在这个领域,这篇通讯试图回顾肠膜病毒在环境环境中传播的可能流入途径,并参考其发生情况,持久性,检测,和灭活基于迄今为止出版的文献。通过载有肠道病毒的气溶胶通过空气传播的可能性,可能影响病毒传播的环境因素,综述了包膜病毒的消毒方法(常规和新兴)以及灭活机制。阐述了对废水流行病学(WBE)研究进行监视和预警信号的需求。这次交流将为理解SARS-CoV-2以及环境工程视角下的其他病毒提供基础,以设计有效的策略来对抗肠道病毒的传播,也是研究人员的工作文件,政策制定者和监管者。
    The unprecedented global spread of the severe acute respiratory syndrome (SARS) caused by SARS-CoV-2 is depicting the distressing pandemic consequence on human health, economy as well as ecosystem services. So far novel coronavirus (CoV) outbreaks were associated with SARS-CoV-2 (2019), middle east respiratory syndrome coronavirus (MERS-CoV, 2012), and SARS-CoV-1 (2003) events. CoV relates to the enveloped family of Betacoronavirus (βCoV) with positive-sense single-stranded RNA (+ssRNA). Knowing well the persistence, transmission, and spread of SARS-CoV-2 through proximity, the faecal-oral route is now emerging as a major environmental concern to community transmission. The replication and persistence of CoV in the gastrointestinal (GI) tract and shedding through stools is indicating a potential transmission route to the environment settings. Despite of the evidence, based on fewer reports on SARS-CoV-2 occurrence and persistence in wastewater/sewage/water, the transmission of the infective virus to the community is yet to be established. In this realm, this communication attempted to review the possible influx route of the enteric enveloped viral transmission in the environmental settings with reference to its occurrence, persistence, detection, and inactivation based on the published literature so far. The possibilities of airborne transmission through enteric virus-laden aerosols, environmental factors that may influence the viral transmission, and disinfection methods (conventional and emerging) as well as the inactivation mechanism with reference to the enveloped virus were reviewed. The need for wastewater epidemiology (WBE) studies for surveillance as well as for early warning signal was elaborated. This communication will provide a basis to understand the SARS-CoV-2 as well as other viruses in the context of the environmental engineering perspective to design effective strategies to counter the enteric virus transmission and also serves as a working paper for researchers, policy makers and regulators.
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  • 文章类型: Journal Article
    背景:普通的成年美国人消耗的含硫氨基酸(SAA)的水平远高于估计的平均需求量(EAR),最近的临床前数据表明,较高的SAA摄入量可能与多种衰老相关的慢性疾病有关。然而,关于SAA摄入量与人类慢性疾病风险之间关系的数据很少。这项研究的目的是检查SAA的消耗与心脏代谢疾病的危险因素之间的关联。
    方法:样本包括第三次全国考试和营养健康调查(NHANESIII)研究(1988-1994)的11,576名成年参与者。主要结果是心脏代谢疾病风险评分(基于血液胆固醇的复合危险因素,甘油三酯,HDL,C反应蛋白(CRP),尿酸,葡萄糖,血尿素氮(BUN),糖化血红蛋白,胰岛素,和eGFR)。按能量调整后的总SAA的五分之一进行风险评分的组差异,蛋氨酸(Met),和半胱氨酸(Cys)摄入量在调整年龄后通过多元线性回归确定,性别,BMI,吸烟,酒精摄入量,和饮食因素。我们进一步检查了SAA摄入量与个体危险因素之间的关联。
    结果:平均SAA消耗量比EAR高2.5倍。经过多变量调整后,SAA的摄入量较高,Met,和Cys与复合心脏代谢疾病风险评分的显着增加相关,独立于蛋白质摄入,和几个单独的危险因素,包括血清胆固醇,葡萄糖,尿酸,BUN,胰岛素和糖化血红蛋白(p<0.01)。
    结论:总体而言,我们的研究结果表明,降低SAA(接近EAR)的饮食与降低心脏代谢疾病的风险相关.低SAA饮食模式依赖于植物来源的蛋白质来源,而不是肉类来源的食物。鉴于大多数成年人的SAA摄入量高,我们的研究结果可能对慢性病预防具有重要的公共卫生意义.
    背景:这项研究没有任何资助。
    BACKGROUND: An average adult American consumes sulfur amino acids (SAA) at levels far above the Estimated Average Requirement (EAR) and recent preclinical data suggest that higher levels of SAA intake may be associated with a variety of aging-related chronic diseases. However, there are little data regarding the relationship between SAA intake and chronic disease risk in humans. The aim of this study was to examine the associations between consumption of SAA and risk factors for cardiometabolic diseases.
    METHODS: The sample included 11,576 adult participants of the Third National Examination and Nutritional Health Survey (NHANES III) Study (1988-1994). The primary outcome was cardiometabolic disease risk score (composite risk factor based on blood cholesterol, triglycerides, HDL, C-reactive protein (CRP), uric acid, glucose, blood urea nitrogen (BUN), glycated hemoglobin, insulin, and eGFR). Group differences in risk score by quintiles of energy-adjusted total SAA, methionine (Met), and cysteine (Cys) intake were determined by multiple linear regression after adjusting for age, sex, BMI, smoking, alcohol intake, and dietary factors. We further examined for associations between SAA intake and individual risk factors.
    RESULTS: Mean SAA consumption was > 2.5-fold higher than the EAR. After multivariable adjustment, higher intake of SAA, Met, and Cys were associated with significant increases in composite cardiometabolic disease risk scores, independent of protein intake, and with several individual risk factors including serum cholesterol, glucose, uric acid, BUN, and insulin and glycated hemoglobin (p < 0.01).
    CONCLUSIONS: Overall, our findings suggest that diets lower in SAA (close to the EAR) are associated with reduced risk for cardiometabolic diseases. Low SAA dietary patterns rely on plant-derived protein sources over meat derived foods. Given the high intake of SAA among most adults, our findings may have important public health implications for chronic disease prevention.
    BACKGROUND: This study does not have any funding.
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  • 文章类型: Journal Article
    UNASSIGNED: Cumulus cells play a crucial role as essential mediators in the maturation of ova. Ginger contains 10-gingerol, which induces apoptosis in colon cancer cells. Based on this hypothesis, this study aimed to determine whether 10-gingerol is able to induce apoptosis in normal cells, namely, cumulus cells.
    UNASSIGNED: This study used an in vitro analysis by culturing Cumulus cells in M199 containing 10-gingerol in various concentrations (12, 16, and 20 μM) and later detected early apoptotic activity using an Annexin V-FITC detection kit.
    UNASSIGNED: The in vitro data revealed that the number of apoptosis cells increased along with the period of incubation as follows: 12 μM (63.71% ± 2.192%); 16 μM (74.51% ± 4.596%); and 20 μM (78.795% ± 1.435%). The substance 10-gingerol induces apoptosis in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.
    UNASSIGNED: These findings indicate that further examination is warranted for 10-gingerol as a contraception agent.
    UNASSIGNED: تلعب الخلايا المحيطة بالبويضة دورا حاسما كوسيط أساسي في نضج البويضات. ويحتوي الزنجبيل على ١٠-جينجيرول، الذي يمكن أن يحفز موت الخلايا المبرمج في خلايا سرطان القولون. واستنادا إلى هذه الفرضية، هدفت هذه الدراسة إلى تحديد ما إذا كان ١٠ جينجيرول قادرا على تحريض موت الخلايا المبرمج في خلايا طبيعية، وتحديدا الخلايا المحيطة بالبويضة.
    UNASSIGNED: استخدمت هذه الدراسة التحليل المختبري للخلايا المحيطة بالبويضة المستزرعة في محلول م ١٩٩ والمحتوي على١٠ جينجيرول في تركيزات مختلفة (١٢، ١٦، و٢٠ ميكرومول) ومن ثم الكشف عن نشاط قاتل للخلايا مبكر باستخدام عدة أنيكسين - فلورسين أيسو ثايو سايانيت للكشف.
    UNASSIGNED: تُظهر البيانات في التجارب المختبرية أن عدد خلايا الموت المبرمج زادت مع زيادة فترة الحضانة: ١٢ ميكرومول (٦٣.٧١٪ ± ٢.١٩٢٪)، ١٦ ميكرومول (٧٤.٥١٪ ± ٤.٥٩٦٪)، و ٢٠ ميكرومول (٧٨.٧٩٥٪ ± ١.٤٣٥٪). تستطيع المادة ١٠ جينجيرول أن تحفز الموت المبرمج للخلايا في الخلايا المحيطة بالبويضة، إلا أنها تثبط وظائف الجين المسؤول عن برمجة مستَقبِل 5- هيدروكسي تريبتامين وتبطل عمل كلا من جلايكوجين سنثايز كاينايز ٣ بيتا والجين المبرمج لـ ” أي كي تي - ١ “.
    UNASSIGNED: تشير نتائج هذه الدراسة إلى أن هناك حاجة لمزيد من الفحص لـ ١٠-جينجيرول كعامل منع للحمل.
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  • 文章类型: Journal Article
    血浆总同型半胱氨酸(tHcy)升高与许多人类疾病有关,包括冠状动脉疾病,中风,骨质疏松症和痴呆症。它与细胞内S-腺苷同型半胱氨酸(SAH)高度相关。由于SAH是涉及甲基供体S-腺苷甲硫氨酸(SAM)的甲基转移反应的强抑制剂,SAH的升高可能是tHcy与人类疾病广泛关联的解释。这里,我们已经创建了转基因小鼠(Tg-hAHCY),该小鼠从肝脏和肾脏中的锌诱导型启动子表达人S-腺苷同型半胱氨酸水解酶(AHCY)。蛋白质分析表明,人类AHCY在肝脏和肾脏中表达良好,但是由于肝脏中内源性小鼠AHCY表达水平高,仅在肾脏中检测到升高的AHCY酶活性(131%增加)。将Tg-hAHCY小鼠与缺乏胱硫醚β-合酶活性的小鼠(Tg-I278TCbs-/-)杂交,以探索在血清tHcy升高和组织SAM和SAH升高的情况下对AHCY过表达的影响。AHCY的过表达对Tg-I278TCbs-/-小鼠的表型没有显著影响或对甲硫氨酸的稳态浓度没有任何影响,总同型半胱氨酸,SAM,SAH,以及肝脏和肾脏中SAM/SAH比率。此外,增强的AHCY活性不会降低血清和组织tHcy或蛋氨酸水平。我们的数据表明,增强AHCY活性不会改变蛋氨酸循环代谢产物的分布,即使它们被Cbs突变大大升高。
    Elevated plasma total homocysteine (tHcy) is associated with a number of human diseases including coronary artery disease, stroke, osteoporosis and dementia. It is highly correlated with intracellular S-adenosylhomocysteine (SAH). Since SAH is a strong inhibitor of methyl-transfer reactions involving the methyl-donor S-adenosylmethionine (SAM), elevation in SAH could be an explanation for the wide association of tHcy and human disease. Here, we have created a transgenic mouse (Tg-hAHCY) that expresses human S-adenosylhomocysteine hydrolase (AHCY) from a zinc-inducible promoter in the liver and kidney. Protein analysis shows that human AHCY is expressed well in both liver and kidney, but elevated AHCY enzyme activity (131% increase) is only detected in the kidney due to the high levels of endogenous mouse AHCY expression in liver. Tg-hAHCY mice were crossed with mice lacking cystathionine β-synthase activity (Tg-I278T Cbs-/- ) to explore the effect to AHCY overexpression in the context of elevated serum tHcy and elevated tissue SAM and SAH. Overexpression of AHCY had no significant effect on the phenotypes of Tg-I278T Cbs-/- mice or any effect on the steady state concentrations of methionine, total homocysteine, SAM, SAH, and SAM/SAH ratio in the liver and kidney. Furthermore, enhanced AHCY activity did not lower serum and tissue tHcy or methionine levels. Our data suggests that enhancing AHCY activity does not alter the distribution of methionine recycling metabolites, even when they are greatly elevated by Cbs mutations.
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  • 文章类型: Journal Article
    维生素B12缺乏症似乎比以前认为的更普遍。然而,只有少数基于新生儿筛查(NBS)计划数据的报告引起了对该主题的关注.在爱沙尼亚,在过去的三年里,我们已经诊断出14名新生儿患有先天性获得性维生素B12缺乏症。因此,这种情况的发生率是33.8/100,000活产,这比以前认为的要多得多。新生儿在治疗前没有任何与维生素B12缺乏相关的临床症状,治疗后所有生化指标恢复正常,这强烈支持维生素B12的可治疗先天性缺乏的存在。在筛选期间,我们开始积极使用一些代谢物的比例,如丙酰基肉碱(C3)与乙酰肉碱(C2)和C3与棕榈酰基肉碱(C16),以提高对获得性维生素B12缺乏的新生儿的识别。根据获得的结果,我们将继续在NBS计划中筛查先天性获得性维生素B12缺乏症。每位患有异常C3,C3/C2和C3/C16的儿童都将接受彻底检查,以排除获得性维生素B12缺乏症,在大多数情况下很容易纠正。
    Vitamin B12 deficiency seems to be more common worldwide than previously thought. However, only a few reports based on data from newborn screening (NBS) programs have drawn attention to that subject. In Estonia, over the past three years, we have diagnosed 14 newborns with congenital acquired vitamin B12 deficiency. Therefore, the incidence of that condition is 33.8/100,000 live births, which is considerably more than previously believed. None of the newborns had any clinical symptoms associated with vitamin B12 deficiency before the treatment, and all biochemical markers normalized after treatment, which strongly supports the presence of treatable congenital deficiency of vitamin B12. During the screening period, we began using actively ratios of some metabolites like propionylcarnitine (C3) to acetylcarnitine (C2) and C3 to palmitoylcarnitine (C16) to improve the identification of newborns with acquired vitamin B12 deficiency. In the light of the results obtained, we will continue to screen the congenital acquired vitamin B12 deficiency among our NBS program. Every child with aberrant C3, C3/C2 and C3/C16 will be thoroughly examined to exclude acquired vitamin B12 deficiency, which can easily be corrected in most cases.
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