Strategies for the development and maturation of functional hepatocytes from hES cells

hES 细胞发育和成熟功能性肝细胞的策略

• 批准号: MR/J006793/1
• 负责人: Melanie Welham
• 金额: $ 111.35万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FJ006793%2F1
• 关键词: Strategies; development; maturation; functional; hepatocytes

Each year companies that develop new medicines spend millions of pounds on tests that are meant to make sure their new drugs are not only effective, but also safe for us to take. In spite of this, the single biggest problem with new medicines is that sometimes they cause damage to the liver, heart or brain, which results in them being taken off the market. This situation could be greatly improved if the companies involved had ways of testing (at an early stage) the safety of new medicines using cells that more closely match those found in normal human liver, heart and brain. Liver transplantation is an effective treatment for patients suffering from life-threatening liver diseases and disorders but the supply of donor organs is severely limited meaning that many people remain on the waiting list each year. New ways to efficiently make functional liver cells would lead to improvements in both of these areas. Many researchers, including our own groups, have shown that it is possible to turn unspecialised cells called stem cells into liver cells, more specifically cells called hepatocytes. It is the hepatocytes in our livers that are responsible for removing harmful products from our blood throughout our lives. At the moment, the hepatocyte-like cells we can generate from stem cells are not as good as proper liver cells and lack the ability to carry out many liver functions. Also, the methods currently used to turn stem cells into liver cells are very expensive and take approximately 4 weeks. In this proposal we want to develop conditions that allow us to turn stem cells into liver cells more efficiently and cheaply. We also want to test for ways in which we can make hepatocyte-like cells that more closely resemble the normal adult liver cells found in humans. To help us do this we will make stem cells that turn on fluorescent signals (which we call reporters) at particular stages as they progress from stem to liver cells. One of these 'reporters' will switch on part way through the process, after about a week, and will help us to improve the generation of cells formed during the early stages of liver development and we also hope to discover how we can increase the numbers of these precursor cells. We will also make a second reporter stem cell line will switch on only when the cells have developed into mature liver cells. We will use this stem cell line to help us work out those conditions that turn stem cells into hepatocyte-like cells that are as close as possible to proper adult liver cells. We will examine whether the liver cells we generate are like normal adult liver cells by examining their properties. We will determine if they contain proteins only found in liver cells and we will study if they contain the enzymes important for metabolising medicines, since these are very important for proper liver cell function. We hope that our results will define conditions that: (i) improve our ability to turn stem cells into liver cells, (ii) help us to expand the number of liver precursor cells we can make, (iii) enable us to generate hepatocyte-like cells that are more like proper adult liver cells and (iv) improve the efficiency and methods of turning stem cells into liver cells so that they are cheaper to make. The availability of mature hepatocyte-like cells from a renewable source of stem cells will be extremely valuable to companies making new medicines, since it will help them develop drugs that should be safer for patients and the time taken to develop them will be reduced, saving money. Not only would stem cell-derived liver cells useful for testing the safety of new medicines, but in the future they may also be valuable as a source of cells for transplantation. Therefore, the improvements in generating functional hepatocyte-like cells that we discover will also help scientists and doctors who are developing cell transplant strategies and artificial livers as alternative treatments for patients requiring liver transplants.

每年，开发新药的公司都会花费数百万英镑进行测试，以确保他们的新药不仅有效，而且对我们来说也是安全的。尽管如此，新药最大的问题是，有时它们会对肝脏、心脏或大脑造成损害，从而导致它们退出市场。如果相关公司有办法（在早期阶段）测试新药的安全性，使用与正常人类肝脏、心脏和大脑中发现的细胞更接近的细胞，这种情况可能会大大改善。肝移植是一种有效的治疗患有危及生命的肝脏疾病和病症的患者的方法，但供体器官的供应严重有限，这意味着每年仍有许多人在等待名单上。有效制造功能性肝细胞的新方法将导致这两个领域的改善。许多研究人员，包括我们自己的团队，已经证明有可能将称为干细胞的非特化细胞转化为肝细胞，更具体地说，是称为肝细胞的细胞。我们肝脏中的肝细胞负责在我们的一生中从我们的血液中清除有害物质。目前，我们可以从干细胞中产生的肝细胞样细胞不如适当的肝细胞，并且缺乏执行许多肝脏功能的能力。此外，目前用于将干细胞转化为肝细胞的方法非常昂贵，需要大约4周的时间。在这项提议中，我们希望开发出一种条件，使我们能够更有效、更便宜地将干细胞转化为肝细胞。我们还想测试我们可以制造肝细胞样细胞的方法，这些细胞更像人类中发现的正常成人肝细胞。为了帮助我们做到这一点，我们将使干细胞在从干细胞到肝细胞的特定阶段打开荧光信号（我们称之为报告基因）。其中一个“报告者”将在大约一周后的过程中部分开启，并将帮助我们改善肝脏发育早期形成的细胞的生成，我们也希望发现如何增加这些前体细胞的数量。我们还将制造第二种报告干细胞系，只有当细胞发育成成熟的肝细胞时，这种干细胞系才会启动。我们将使用这种干细胞系来帮助我们解决将干细胞转化为肝细胞样细胞的条件，这些细胞尽可能接近正常的成体肝细胞。我们将通过检查它们的特性来检查我们生成的肝细胞是否像正常的成人肝细胞。我们将确定它们是否含有仅在肝细胞中发现的蛋白质，我们将研究它们是否含有对代谢药物重要的酶，因为这些酶对正常的肝细胞功能非常重要。我们希望我们的研究结果将定义以下条件：（i）提高我们将干细胞转化为肝细胞的能力，（ii）帮助我们扩大我们可以制造的肝脏前体细胞的数量，（iii）使我们能够产生更像正常成人肝细胞的肝细胞样细胞，以及（iv）提高将干细胞转化为肝细胞的效率和方法，使它们更便宜。从可再生的干细胞来源获得成熟的肝细胞样细胞对制造新药的公司来说将是非常有价值的，因为它将帮助他们开发对患者更安全的药物，并且开发它们所需的时间将减少，节省资金。干细胞衍生的肝细胞不仅可用于测试新药的安全性，而且在未来它们也可能作为移植细胞的来源。因此，我们发现的产生功能性肝细胞样细胞的改进也将帮助科学家和医生开发细胞移植策略和人工肝作为需要肝移植患者的替代治疗。

项目成果

MicroRNA-122: a novel hepatocyte-enriched in vitro marker of drug-induced cellular toxicity.

• DOI: 10.1093/toxsci/kfu269
• 发表时间: 2015-03
• 期刊: Toxicological sciences : an official journal of the Society of Toxicology
• 作者: Kia R;Kelly L;Sison-Young RL;Zhang F;Pridgeon CS;Heslop JA;Metcalfe P;Kitteringham NR;Baxter M;Harrison S;Hanley NA;Burke ZD;Storm MP;Welham MJ;Tosh D;Küppers-Munther B;Edsbagge J;Starkey Lewis PJ;Bonner F;Harpur E;Sidaway J;Bowes J;Fenwick SW;Malik H;Goldring CE;Park BK
• 通讯作者: Park BK