Applying lipidomics strategies to study lipid metabolic diseases
Zhang, Wenxuan
DOI:
10.33612/diss.169407826
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Publication date: 2021
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Zhang, W. (2021). Applying lipidomics strategies to study lipid metabolic diseases. University of Groningen. https://doi.org/10.33612/diss.169407826
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Appendices
Summary
Nederlandse samenvatting
Acknowledgements
Curriculum vitae
List of publications
Summary
Lipids are groups of metabolites that have very variable crucial physiological roles. Lipids come in an extremely wide variety of configurations. For instance, triglycerides function as energy stores in several tissues and organs of our body. Triglycerides are composed of highly lipophilic compounds, i.e., fatty acids esterified to glycerol. These molecules can be packaged into lipoproteins and distributed over the various organs via the circulation. Phospholipids and sphingolipids constitute building blocks of membranes of cells and their subcellular organelles, i.e., the endoplasmic reticulum, Golgi complex, endosomal-lysosomal system, mitochondria, peroxisomes, etc. These lipids are composed of a hydrophilic ‘head’-group attached to a lipophilic ‘tail’-group, mostly consisting of fatty acids. Variation in the composition of the head-group orthogonal to that in the tail-group generates thousands of individual lipid species. Sterols, in particular cholesterol, serve as precursors of steroid hormones and bile acids, but are also important constituents of biological membranes. The thousands of lipid species are distributed unevenly over the cellular membranes in an organelle-specific manner and a proper distribution of all these lipid species is pivotal to the functioning of the cell. From a bigger perspective, the well-organized distribution of lipid species appears to be tissue-specific and possibly reflects nutritious state as well as the (patho) physiological state of the body. Thus, the pattern of distribution and composition of lipid species in different biological materials could provide valuable information about health status and disease development. Lipidomics refers to the omics-technology that allows us to get access to this important information. It combines sophisticated analytical techniques primarily based on mass spectrometry and advanced software tools. This combination is pivotal to identify and quantify hundreds to thousands of lipid species at the same time. Statistical tools to rapidly and comprehensively analyze the acquired data further improve the applicability of lipidomics for a wide range of biological and clinical questions.
In this thesis, the aims were (i) to address the current concerns in pre-analytical stages of lipidomics approaches, (ii) to establish an untargeted lipidomics workflow for different biological applications (Part I) and (iii) to apply this workflow to elucidate relationships between lipid profiles and various metabolic disorders (Part II). Finally, in Part III, the major findings of the studies performed in this thesis and future directions in lipidomics were discussed.
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Summary
Along with the rapid growth of technical advances, lipidomics is still on the way of standardization to ensure the reproducibility and accuracy of the results obtained. In 2019, the Lipidomics Standards Initiative (LSI) Consortium was established to ensure reproducibility and accuracy of results obtained by different lipidomics workflows and uniformity in their reporting. Currently, this process is still in progress and also addresses new concerns that arise at different stages of the lipidomics workflow. In Part I, Chapter 2, we discussed the existing challenges and considerations of the pre-analytical stage including experimental design, sample collection and lipid extraction. In Chapter 3, we evaluated four different lipid extraction procedures in plasma samples. We assessed their reproducibility by comparing the number of reproducibly measured compounds extracted by different procedures. We also assessed their extraction efficiencies across different lipid classes. The data indicated that the MMC solvent mixture (MeOH/MTBE/CHCl3) was most adequate for the plasma lipidome and showed the best extraction efficiencies for moderate and highly apolar lipid species.
In Part II, Chapter 4, we investigated the plasma lipid profiles in individuals who presented with extremely high or low levels of LDL-cholesterol, selected from a large general population cohort from the North of the Netherlands (LifeLines). The close relationship between the composition of plasma lipidomic profiles and the genetic origins of extremely low levels of LDL-cholesterol indicates the potential of involving lipidomics as an important information layer in large scale studies to assist tracing the origins of dyslipidemia.
In Chapter 5, we focused on an inborn error of metabolism of fatty acids, medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, which is a monogenic disorder of mitochondrial fatty acid oxidation. To understand the pathology of the disease caused by severely impaired fatty acid oxidation, we analyzed lipid profiles from multiple organs and blood of MCAD knockout mice during fasting and cold exposure. Lipidomics analysis of lipids extracted from liver, Brown adipose tissue (BAT) and blood of MCAD knockout mice revealed the important role of triglycerides to accommodate excessive amounts of medium chain fatty acids in order to avoid accumulation of these toxic products due to the genetic defect. Similar strategies might be adopted by MCAD-deficient patients, which makes further investigation in human samples worthwhile. Additionally, some plasma lipids, e.g. TG(44:3) and TG(44:2), which were significantly changed in MCAD knockout mice, could be studied and validated as additional markers for disease severity.
In Chapter 6, we utilized the power of multiple omics techniques to comprehensively depict complex phenotypes at several molecular levels. We studied the regulatory role of the core transcription factor LRH-1 in hepatic lipid metabolism with or without dietary stress induced by a ‘McDonald’s diet’. LRH-1 knockdown (KD) mice presented with a phenotype of mild fatty liver disease under chow diet but severe non-alcoholic steatotic hepatitis with bridging fibrosis when fed this typical Western-type diet. Integrative analysis of hepatic transcriptomics, proteomics and lipidomics profiles of LRH-1 KD mice showed that alterations occurred in different aspects of hepatic lipid metabolism, i.e., impaired cholesterol transport and esterification, altered very long chain fatty acid synthesis, reduced phosphatidylethanolamine N-methyltransferase (PEMT)-catalyzed phosphatidylcholine synthesis and upregulation of sphingolipid biosynthesis. These multi-omics observations combined with pathophysiological data greatly advanced our understanding of the role of LRH-1 in the maintenance of hepatic lipid homeostasis , highlighting the pivotal role of LRH-1 in adequate adaptation of hepatic lipid metabolism when stressed with a Western-type diet.
Part III, Chapter 7 discusses the major findings of this thesis. Then, I highlighted the remaining technical and post-analytical challenges and opportunities of integrating lipidomics with other omics techniques for clinical research and in the clinical work-up of patients with an undiagnosed disease.
Lipidomics is a rapidly growing field of research. In this thesis, we made our contributions to establishment of a functional lipidomics workflow, its application in (pre-) clinical studies on metabolic diseases, and the integration of lipidomics into multi-omics analytical procedures.
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Nederlandse samenvatting
Lipiden zijn metabolieten die een grote rol spelen in essentiële fysiologische functies en komen in een zeer grote verscheidenheid aan configuraties voor. Triglyceriden functioneren bijvoorbeeld als energiereserves in verschillende weefsels en organen van ons lichaam. Triglyceriden zijn samengesteld uit sterk hydrofobe verbindingen, d.w.z. vetzuren die veresterd zijn met glycerol. Deze moleculen kunnen worden verpakt tot lipoproteïnen en via de circulatie over de verschillende organen worden verdeeld. Fosfolipiden en sfingolipiden vormen bouwstenen van membranen van cellen en hun subcellulaire organellen, zoals het endoplasmatisch reticulum, Golgi-complex, endolysosomale systeem, mitochondriën, peroxisomen, enz. Deze lipiden zijn samengesteld uit een hydrofiele ‘kop’-groep gekoppeld aan een hydrofobe ‘staart’-groep, die voornamelijk bestaat uit vetzuren. Variatie in de samenstelling van de kopgroep orthogonaal aan die in de staartgroep genereert duizenden individuele lipiden. Sterolen, in het bijzonder cholesterol, dienen als voorlopers van steroïde hormonen en galzuren, maar zijn ook belangrijke bestanddelen van biologische membranen. De duizenden verschillende lipiden zijn niet gelijkmatig verdeeld over de membranen in de cel maar zijn verdeeld op een organel-specifieke manier en de juiste distributie van al deze lipiden is essentieel voor het functioneren van de cel. Vanuit een breder perspectief lijkt een goed georganiseerde verdeling van lipiden weefselspecifiek te zijn en mogelijk een weerspiegeling van zowel de voedingstoestand als de (patho) fysiologische toestand van het lichaam. Het patroon van verdeling en samenstelling van lipiden in verschillende biologische materialen zou dus waardevolle informatie kunnen opleveren over de gezondheidstoestand van een individu en de ontwikkeling van ziekten. Lipidomics verwijst naar de “omics-technologie” waarmee we toegang krijgen tot deze belangrijke informatie. Lipidomics combineert geavanceerde analytische technieken, voornamelijk gebaseerd op massaspectrometrie, en specifieke softwaretools. Deze combinatie is cruciaal om honderden tot duizenden lipiden tegelijkertijd te identificeren en te kwantificeren. Statistische hulpmiddelen om de verkregen gegevens snel en volledig te analyseren, verbeteren de toepasbaarheid van lipidomics voor een breed scala aan biologische en klinische vragen.
De doelstellingen in dit proefschrift waren; (i) het aanpakken van de huidige problemen in de pre-analytische fase in lipidomics, (ii) het opzetten van een algemene lipidomics-pijplijn voor verschillende biologische toepassingen (Deel I) en (iii) het toepassen van deze pijplijn op het verband tussen lipidenprofielen en verschillende stofwisselingsstoornissen (Deel II). In Deel III worden de
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Nederlandse samenvatting
belangrijkste bevindingen van de studies in dit proefschrift besproken gevolgd door een beschouwing van toekomstige ontwikkelingen in lipidomics .
Naast de snelle technische vooruitgang, wordt in het veld van de lipidomics veel tijd besteed aan standaardisatie om de reproduceerbaarheid, nauwkeurigheid en rapportage van de verkregen resultaten te verbeteren. In 2019 werd daartoe het Lipidomics Standards Initiative Consortium opgericht om de reproduceerbaarheid en nauwkeurigheid van de resultaten verkregen met verschillende lipidomics-pijplijnen en uniformiteit van rapportage te garanderen. Dit proces is nog volop aan de gang en er worden nog steeds nieuwe problemen in verschillende fasen van de lipidomics-pijplijn geagendeerd. In Deel I, Hoofdstuk 2, hebben we de bestaande uitdagingen en overwegingen van de pre-analytische fase besproken, inclusief het ontwerpen van experimenten, de monsterverzameling en lipidenextractie. In Hoofdstuk 3 zijn vier verschillende lipidenextractie procedures van plasmamonsters geëvalueerd. De reproduceerbaarheid en extractie-efficiëntie werden beoordeeld op basis van een vergelijking van een serie lipidensoorten, van polaire vetzuren tot apolaire triglyceriden. De resultaten lieten zien dat een vloeistofmengsel van methanol, methyl tert-butyl ether en chloroform het meest geschikt was voor extractie van het plasma lipidoom met een hoge extractie-efficiëntie die in geringe mate omgekeerd evenredig was met de polariteit van de lipiden.
In Deel II, Hoofdstuk 4, onderzochten we de plasma lipidenprofielen van individuen met extreem hoge of lage niveaus van LDL-cholesterol, geselecteerd uit een groot algemeen populatiecohort uit Noord-Nederland (LifeLines). Het sterke verband van de lipidensamenstelling van plasma met de genetische oorsprong van extreem lage niveaus van LDL-cholesterol geeft aan dat lipidomics een belangrijke informatielaag vormt in grootschalige studies naar de oorsprong van dyslipidemieën.
In Hoofdstuk 5 hebben we ons gericht op een aangeboren afwijking van het metabolisme van vetzuren, middellange keten acyl-CoA dehydrogenase (MCAD) deficiëntie, een monogenetische aandoening van de mitochondriale vetzuuroxidatie. Om de pathologie te begrijpen van deze ziekte die een ernstig vermindering veroorzaakt van de vetzuuroxidatie, analyseerden we lipidenprofielen van meerdere organen en bloed van MCAD-knock-out muizen na vasten gevolgd door blootstelling aan kou. Lipidomics van lipiden geëxtraheerd uit bloed, lever, bruin vetweefsel en wit vetweefsel van MCAD knock-out muizen liet zien dat triglyceriden een belangrijke rol spelen om de overmatige productie van vetzuren met middellange ketens te neutraliseren,
waardoor ophoping voorkomen werd van deze giftige producten als gevolg van het genetisch defect. Vergelijkbare processen kunnen ook optreden in patiënten met MCAD-deficiëntie, wat verder onderzoek in plasma monsters van deze patiëntengroep de moeite waard maakt. Bovendien kunnen sommige plasmalipiden, b.v. TG (44:3) en TG (44:2), die significant verhoogd waren in MCAD-knock-outmuizen, gevalideerd worden als aanvullende markers voor de ernst van het ziektebeeld.
In Hoofdstuk 6 hebben we de combinatie van meerdere omics-technieken gebruikt om complexe fenotypes op verschillende moleculaire niveaus uitgebreid in kaart te brengen. We bestudeerden de regulerende rol van de transcriptiefactor LRH-1, centraal in het lipidenmetabolisme van de lever, met of zonder de stress veroorzaakt door een ‘McDonald’s-dieet’. LRH-1 knockdown (KD) muizen op het controle dieet lieten een fenotype zien met milde leververvetting , maar op het typische westerse dieet vertoonden de LRH-1 KD muizen een ernstige niet-alcoholische steatotische hepatitis met fibrose. De combinatie van de analyses van het transcriptoom, proteoom en lipidoom van leverweefsel van LRH-1 KD-muizen toonde aan dat er veranderingen optraden in verschillende aspecten van het lever lipiden metabolisme, d.w.z. verminderd cholesteroltransport en verestering, veranderde synthese van zeer lange keten vetzuren, verminderde fosfatidylcholine-synthese gekatalyseerd door fosfatidyletanolamine methyltransferase (PEMT) en stimulering van de biosynthese van sfingolipiden. Deze multi-omics-waarnemingen, gecombineerd met pathofysiologische gegevens, hebben ons begrip van de rol van LRH-1 bij het in stand houden van lever lipidenhomeostase aanzienlijk vergroot, en benadrukken de cruciale rol van LRH-1 bij een adequate aanpassing van het levermetabolisme bij stress geïnduceerd door een typisch westers eetpatroon.
In Deel III, Hoofdstuk 7 worden de belangrijkste bevindingen van dit proefschrift besproken. Vervolgens belicht ik de resterende technische en post-analytische uitdagingen en kansen van de integratie van lipidomics met andere omics-technieken voor klinisch onderzoek en in het klinische onderzoek van patiënten met een niet-gediagnosticeerde ziekte.
Lipidomics is een snel groeiend onderzoeksgebied. In dit proefschrift hebben we onze bijdrage geleverd aan het opzetten van een functionele lipidomics-pijplijn, de toepassing ervan in (pre-) klinische studies van metabole ziekten en de integratie van lipidomics in multi-omics-analytische procedures.
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中文摘要
脂质家族是一族具有重要生理功能的代谢物。脂质家族的成员组成呈现出极大 的多样性。例如，甘油三酸酯是由高度亲脂性的化合物，即三条脂肪酸链与一 分子甘油通过酯化反应而生成。这些甘油三酸酯可以包装成脂蛋白，并通过血 液循环分配到各个器官，并在人体的多个组织和器官中充当能量储存器。而磷 脂和鞘脂则由亲水性“头部”基团和亲脂性“尾部”基团 （通常为脂肪酸）构成， 多种类型的头部基团与多种类型尾部基团可以通过正交组成产生数千种不同的 的脂质分子，这些分子是构成细胞及其亚细胞器细胞膜的结构单元，例如内质 网，高尔基体，内体-溶酶体系统，线粒体，过氧化物酶体等。甾醇，尤其是胆 固醇，是甾体激素和胆汁酸的前体，同时也是生物膜的重要组成部分。成千上 万种的脂质根据其所在细胞器的特异性不均匀地分布在细胞膜上，而这些脂质 分子的正确分布对于细胞的正常运作至关重要。从宏观角度分析，脂质分子的 分布也有组织特异性，而且有可能反映了人体的营养状态以及（病理）生理状 态。因此，对比不同生物样品中脂质分子的组成和含量可以提供有关生物体健 康状况和疾病发展相关有价值的信息。脂质组学作为一门新兴学科，能够对生 物样品中的整体脂质进行系统分析，从而使我们能够快速了解生物样品中脂质 分子的各种变化。得益于质谱技术及相应的数据处理工具的快速更新，现在我 们可以同时鉴定和定量数百至数千种脂质。新开发的多种数据统计工具则进一 步提高了脂质组学在生物学和临床研究中的适用性。 本论文共有三部分内容（i）归纳及讨论脂质组学在样品制备阶段存在的挑战， （ii）建立针对不同生物学应用的非靶向脂质组学工作流程（第一部分），以及 （iii）将脂质组学应用于阐明脂质分布与多种代谢紊乱之间的紧密关联（第二 部分）。最后，本论文的第三部分讨论了论文中的主要研究发现以及脂质组学 的未来发展方向。 随着脂质组学相关技术的不断进步，脂质组学对其实验流程标准化的要求也不 断更新，从而确保所得结果的可重复性和准确性。2019年，脂质组学标准计划 （LSI）联盟的建立标志着人们更加关心不同脂质组学工作流程所获得的结果的 可重复性和准确性。当前，LSI仍在不断更新脂质组学样品处理中可能出现的不 同注意事项和新挑。在第一部分的第2章中，我们讨论了脂质组学样品处理中包 括实验设计阶段，样品收集阶段和脂质提取阶段的现有挑战。在第3章中，我 们进一步评估了四种不同的脂质抽提方法对血浆样品中脂类的抽提效率及稳定 性。我们首先通过比较不同抽提方法多组平行样中可重复检测到的化合物数量 来评估抽提方法的可重复性。我们还评估了这些方法对于不同脂质类别的提取 效率。数据表明，MMC溶剂混合物（甲醇 / 甲基叔丁基醚 / 氯仿）最适合用于 提取血浆中的脂质，其对中度和高度非极性脂质种类显示出最佳的萃取效率。195 |
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中文摘要 在第二部分的第4章中，我们从荷兰北部人群中挑选出低密度脂蛋白-胆固醇 （LDL-c）水平极高或极低的个体，并研究了他们的的血浆脂质谱。研究中发现 血浆脂质谱中的脂类组成与导致LDL-c水平极低的遗传因素之间存在密切关系。 同时这项研究表明，脂质组的研究有潜力有作为大规模人口遗传研究中新的重 要信息层，并有助于追踪血脂异常的根本原因。 在第5章中，我们重点研究了脂肪酸代谢途径中的先天性单基因缺陷症，即中链 酰基辅酶A脱氢酶（MCAD）的缺乏。为了研究由严重受损的脂肪酸氧化代谢途 径而引起的疾病病理和适应机制，我们分析了禁食和寒冷刺激下的MCAD基因 敲除小鼠中多个器官和血液样品的脂质分布。从MCAD基因敲除小鼠的肝脏， 棕色脂肪和血液中提取的脂质进行的脂质组学分析显示，甘油三酸酯具有重要 的作用，可以容纳由于MCAD缺陷而产生的过量中链脂肪酸，从而避免有毒产 物的积聚。由此推论，缺乏MCAD的患者可能会采用类似的策略，因此值得我 们对人体样本进行进一步研究。另外，在MCAD基因敲除小鼠的血浆中，一些 血浆脂质例如TG（44：3）和TG（44：2）发生了显著变化，可以进行进一步 研究并验证其作为预测疾病严重程度的靶标的可能性。 在第6章中，我们利用了多种组学技术，全面地阐述了分子水平上的复杂表型。 我们研究了在高糖高脂饮食和普通饮食条件下，核心转录因子LRH-1在肝脏脂质 代谢中所起的调控作用。 LRH-1敲低（KD）小鼠在低脂饮食下表现为轻度脂肪 肝，但在饲喂典型的西式饮食时表现为严重的非酒精性脂肪性肝炎，并伴有肝 纤维化。对LRH-1 KD小鼠的肝转录组学，蛋白质组学和脂质组学图谱的综合分 析表明，肝脏中的一些脂质代谢通路发生了改变，例如胆固醇转运和酯化过程 受损，超长链脂肪酸合成通路改变，磷脂酰乙醇胺N-甲基转移酶 （PEMT）催 化的磷脂酰胆碱合成减少以及神经酰胺合成水平上调。这些多组学的分析结果 与病理生理学数据相结合，极大地增进了我们对LRH-1在维持肝脏脂质稳态中作 用的理解，突显了LRH-1在高糖高脂刺激下对肝脏脂质代谢的关键调控作用。 第三部分，第7章讨论了本论文的主要发现以及重点介绍了将脂质组学与其他组 学技术整合用于临床研究及未确诊疾病患的临床检查中仍然存在的技术难题以 及机遇。 脂质组学是一个快速发展的研究领域。在本论文中，我们为建立功能性脂质组 学工作流程，将其应用在代谢疾病的（预）临床研究中以及将脂质组学整合到 多组学分析中做出了微小的贡献。Acknowledgements
When I am writing the acknowledgement, a lot of unforgettable memories come to my mind and remind me of all these years of enjoyable time in Groningen. I got to know many lovely people, my supervisors, my colleges, my friends, who supported me and gave great contributions to my thesis.
First of all, I would like to thank my supervisors, who offered me the great chance to work on my PhD projects and continuously guided me during my PhD study. My first promotor, Prof. F. Kuipers, Dear Folkert, it is a great pleasure to have you as my promotor and to work with you. Although you are very busy managing research and lab affairs as the head of Pediatrics, whenever I need your suggestions and support, you are always very glad to give your valuable input and help me out from struggling in the research puzzles. I really hope we could continue our collaborations and generate a nice output in the near future. My co-promotor, Prof. R.P.H. Bischoff, Dear Rainer, I was working as a master student in your lab and you introduced the whole world of mass spectrometry. Thanks for all the meetings we have together which always inspired me to think of my projects from different angles . You also taught me how to think critically and how to build my analytical thought. I wish you will keep enjoying science and life after your official retirement.
My co-promotor, Prof. D.J. Reijngoud, Dear Dirk-Jan, there is so much I want to say to you. I learned the real meaning of the word gentleman after these years working together with you. Thanks to all the freedom and trust you give to me during my PhD. You always support my ideas and encourage me to give a try and to collaborate. You always glad to share your valuable knowledge and experience with me in metabolism, in inborn error diseases, in English writing skills, in communications and more. I really hope the epidemic will be over soon and you could start plan your second trip to China.
Dear prof. dr. P.L. Horvatovich, dr. H.P. Permentier, dr. M.R. Heiner-Fokkema, Theo, thanks for attending my lipidomics regular meeting and give your valuable input in data acquisition, data analysis and mass spectrometry handling. Dear prof. dr. B.M. Bakker and prof. dr. JA Kuivenhoven, I learned a lot from our collaborations, thanks for offering me the chances to work with different research topics and to learn from your expertise in lipid metabolic diseases.
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Acknowledgements
Dear Karin, my master and my PhD daily supervisor, my paranymph as well as my very good friend, we knew each other for 6 years. During my PhD, the other paranymph of mine, Anastasia joined us, and the three of us had a lot of good times together. We discussed research, we played card games, we visited Greece. There are a lot more to mention, and we will see each other soon for sure. Yang, who is not only my collaborator, but also my dear friend, I am so glad that I met you here. You inspired me a lot in our collaborations and I enjoyed every moment I spent with you. We will see each other in Shanghai. I also would like to thank Andres, who worked with me on lipidomics for more than two years, I missed the days that we handled the “beast” MS together. Andrei, we always went downstairs for the best coffee and I learned so much about data analysis from you. Hope your new life in Amsterdam is full of happiness. Thanks also goes to my lab mates on Eriba 6th Floor. I enjoyed working with all of you
and the small coffee breaks we had together. Marcel, you are the coolest MS specialist. It could be even better if you decide not to call me Wendy. Ydwine, I missed your laugh and thanks for taking good care of all the plants in our lab. Jos, Annie, Margot, Walid, Natalia, Jan Willem, you are always so kind and so helpful. Ali, thanks for enjoying Chinese lunch, and I am sure all of your hard workings deserve. Best wishes also goes to your wife. Alex, your explanation on data analysis was always very clear and I missed the delicious cheesecake from your wife. Xiaobo, you are not only a very good researcher, but also a chef from Sichuan province of China. Xiaodong, happy to see that you are continuing working on lipidomics, Hope you, Xiaobo, Janine, Alienke, Sara, Oladapo, Baubek and Victor a very successful PhD. Larry, Tao, Jiaying, Frank and Peter, although you graduated or left the lab during my PhD, I still missed the old times and the gatherings together.
Thanks also goes to my colleges in Pediatrics. Vincent, thanks for all your valuable comments and suggestions on omics data. I felt so enjoyable to collaborate with you and learned from your experience. Jan Freark, your input as a specialist of lipid metabolism and fatty liver diseases always inspired me to think one step further on my work. Anne-Claire, I really admire your conscientious attitude on the work and your brilliant ideas on data interpretation, We will finalize our collaborations together. Maaike, thanks for your encouragement and your valuable suggestions. Antoine, thanks very much for all your time and patience on the lifelines study and hope everything goes very well in France. Marcel and Albert, you are always so nice and I enjoyed collaborating with you. Hope you enjoyed your research and life in Groningen. Paula, Evelien and Hilde, you are always so patient and so nice explaining me and helping me with all administrative affairs. Best wishes also goes to
Melany, Emmalie, Liga, Fentaw, Bernard, Natalia, Alex, Patricia, Niels, Aycha, Nicolette, Karen and all other colleges came from the Pediatrics family. I also would like to thank my Chinese friends from other departments, who make me feel warm and not too far away from home. Yehan, Xing, Haiyan, Huala, Jue, we are the best teammates for dinners, for birthdays, for chatting and for games. There were so many good times we spent together and being relax from work. Wish Yehan and Huala settled well with their new jobs, Xing and Jue will graduate soon, Haiyan will reunit with family in a short time. I also missed the time spent with Keni and Yang, I ccouldn’t remember how many nights that we were biking home together, went to gym together and hanging out together. So glad to knew that you two planned to settle not far away from my city. Chengying, I got to know you when I started my master study. I missed the chat we had about philosophy. Although I didn’t manage to visit you in London, I sincerely hope that you have a wonderful life there. Siwen and Yue, I knew you two for six years, there are many moments to remember, lets keep in touch. Wenjun, I still remembered all the warm helps you offered me when I was new in Groningen, please posted more lovely pictures of your doughter. Tian, Daili, Xiaoyin, Yuxi and Dong, Thanks for the great times we spent together and the warm goodbye you said to me when I left Netherland. Together with Zhenchen and Teke, I always know a place we can still garther together in the future. Also thank fellows from the next building, Yana, Yizhou, Shanshan, Haigen, Yu, Hao, Lin, Bin, Chao, Xiaoxiang, Jingyao and more friends.
Last but not least, I would like to thank the love from my families in China. My loving husband, Wei, who continuesly support me among all these years, listen to me, understand me, encourage me, visit me, take care of my parents and grandparents. Without him, I’m not able to finish my PhD study and my thesis. Also the love from other family members of mine, especially my mom, always encourage me to improve myself, to be positive and to be brave. Thanks for making me a better person.
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Curriculum vitae
Wenxuan Zhang was born on September 22th in Xi’an, China. In 2009, she
started her Bachelor studies in Life Science and Technology at Northwest University in Xi’an. After she received her B.Sc. degree in 2013, she moved to the Netherland and continued her master studies in Biomolecular Sciences in University of Groningen. During her master, she conducted two projects entitled “Towards single molecule localization studies of the Sec translocase components” and “SRM-Based Quantification and Validation of Nuclear Transport Factors” under the supervision of prof. dr. A.J.M. Driessen and Prof. R.P.H. Bischoff. In 2015, she obtained her M.Sc. degree from the top track of Biomolecular Sciences program in university of Groningen. At the end of the same year, she started her PhD project at the Center for Liver, Digestive and Metabolic Disease in Pediatrics department, University Medical Center of Groningen under the guidance of Prof. F. Kuipers, Prof. R.P.H. Bischoff and Prof. D.J. Reijngoud. During her PhD, she went to Imperial College of London and University of Leipzig for two training programs. She also presented her work on several national and international conferences. The result of her research works are presented in this PhD dissertation. In February 2021, she started her new job as a senior scientist in WuXi Biologics.
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List of publications
1. Gil A*, Zhang W*, Wolters JC, et al. One- vs two-phase extraction: re-evaluation of sample preparation procedures for untargeted lipidomics in plasma samples. Anal Bioanal Chem. 2018;410(23):5859-5870. doi:10.1007/s00216-018-1200-x
2. Gil A*, Zhang W*, Wolters JC, et al. Omics | lipdomics and its pitfalls during the pre-analytical stage. In: Encyclopedia of Analytical Science. Elsevier; 2019:70-81. doi:10.1016/B978-0-12-409547-2.14002-8
3. Feng X, Zhang W, Kuipers F, Kema I, Barcaru A, Horvatovich P. Dynamic binning peak detection and assessment of various lipidomics liquid chromatography-mass spectrometry pre-processing platforms. bioRxiv. Published online October 10, 2020:2020.10.10.334342. doi:10.1101/2020.10.10.334342
4. Vieira-Lara MA, Dommerholt MB, Zhang W, et al. Age-related susceptibility to insulin resistance is due to a combination of CPT1B decline and lipid overload. bioRxiv. Published online February 4, 2021:2021.02.04.429529. doi:10.1101/2021.02.04.429529
5. Zhang W, Rimbert A, Wolters JC, et al. The plasma lipidome of individuals with extreme levels of LDL-c. In preparation.
6. Martines AMF*, Zhang W*, Gerding A et al. The role of hepatic fatty-acid oxidation during cold stress: remodelling of whole body energy and lipid
metabolism in Acadm-knockout mice. In preparation.
7. Zhang W*, Zhang Y*, Bloks VW et al. Low LRH-1 expression in mice promotes development of Western-type diet-induced steatohepatitis and liver fibrosis -Multi-omics integration reveals a critical role of LRH-1 in adequate adaptation of hepatic lipid metabolism to nutrient overload. In preparation.
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