The Role of Nanog in Establishment and Patterning of Embryonic Pluripotency

Nanog 在胚胎多能性建立和模式化中的作用

• 批准号: MR/L001047/1
• 负责人: Andrew Johnson
• 金额: $ 64.15万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FL001047%2F1
• 关键词: Role; Nanog; Establishment; Patterning; Embryonic

Embryonic stem (ES) cells can become any cell in the body, and so they have great potential as a tool for regenerative medicine to repair tissue damaged by injury or disease. A major goal of modern medicine, therefore, is to understand how to harvest the potential of embryonic stem cells for therapeutic purposes. The signature ability of ES cells to become other cells is called pluripotency, which is carefully regulated by protein factors, called pluripotency factors, which control the genes that regulate ES cell behaviour. We are working to identify how those genes are controlled, and we have focused on one of the most important pluripotency factors, called Nanog, a master regulator of stem cell behaviour.ES cells resemble the cells that make up early embryos, and so by understanding how embryos develop it becomes it is possible to learn how to regulate ES cells to make specific types of adult cells. However, to understand how ES cells become pluripotent, it is necessary to consider the establishment of pluripotency in the embryo itself. However, the embryos of humans, and other mammals, are very small, and they develop inside the mother, so they are very difficult to access and to manipulate. A way around this problem is use the embryos of other species, whose cells resemble those of human embryos, but which are much easier to work with. This approach has been used for decades in biology to identify the function of genes in embryonic cells. However, we discovered that the embryos of frogs and fish, which most investigators use in the lab, do not contain pluripotent cells. For this reason we had to develop a novel experimental system using embryos from axolotls.Mammals evolved from amphibians, of which there are two types, frogs and salamanders. These two types of amphibians last had a common relative 250 million years ago. Since then, frogs have evolved many traits are unique to them, however salamanders have remained relatively unchanged since they first walked the earth, and they evolved into reptiles and mammals. For this reason, the genes that control the development of embryos from salamanders and mammals are almost the same. In fact, axolotls are representative salamanders, and we have shown that they contain pluripotent cells that are basically the same as the ones that develop in human embryos. Also, importantly, they contain a Nanog gene, which for reasons that are not entirely clear, does not exist in frog embryos. For our purposes axolotl embryos are a perfect tool to understand how pluripotent cells respond to signals that tell them to become other cell types. We are using axolotl embryos to study how Nanog is regulated.Axolotl embryos develop outside of the mother, so hundreds of embryos can be collected without harming the animals. Also, the embryos are enormous, about 10,000 times the size of human embryos, so it is very easy to dissect the cells you want to study in the lab. The axolotl experimental system that we developed is unique in the UK, and we are the only group in the world currently using it to understand pluripotency. When we isolated the Nanog gene from axolotls we showed that it works as well as human Nanog in controlling the behaviour of ES cells. But ES cells are not embryos, and we have the unique opportunity to understand how Nanog functions in a normal embryo, the embryo of an axolotl.In this project we will take the pluripotent cells in axolotl embryos and induce them to become specific types of differentiated cells using solutions that contain the molecules that control development of normal embryos. We will then analyse how the loss of Nanog changes the response to these signals. By identifying how the cells respond we will understand the necessary first step in the establishment of pluripotency, and this will provide cues for how to produce human tissue for regenerating damaged body parts.

胚胎干细胞（ES）可以成为体内的任何细胞，因此它们作为再生医学的工具具有巨大的潜力，可以修复因损伤或疾病而受损的组织。因此，现代医学的一个主要目标是了解如何收获胚胎干细胞用于治疗目的的潜力。胚胎干细胞变成其他细胞的特征能力被称为多能性，它受到蛋白质因子的精心调控，这些蛋白质因子被称为多能性因子，它们控制着调控胚胎干细胞行为的基因。我们正在努力确定这些基因是如何被控制的，我们已经把重点放在了最重要的多能性因子之一，称为Nanog，它是干细胞行为的主要调节器。ES细胞类似于构成早期胚胎的细胞，因此通过了解胚胎如何发育，我们就有可能了解如何调节ES细胞以产生特定类型的成体细胞。然而，要了解胚胎干细胞是如何成为多能性的，就必须考虑胚胎本身多能性的建立。然而，人类和其他哺乳动物的胚胎非常小，它们在母体内发育，因此很难接近和操纵。解决这个问题的一个方法是使用其他物种的胚胎，它们的细胞与人类胚胎相似，但更容易使用。几十年来，这种方法一直用于生物学中，以确定胚胎细胞中基因的功能。然而，我们发现大多数研究人员在实验室中使用的青蛙和鱼的胚胎不含有多能细胞。因此，我们必须开发一种新的实验系统，使用蝾螈的胚胎。哺乳动物是从两栖动物进化而来的，两栖动物有两种类型，青蛙和蝾螈。这两种两栖动物最后一次有共同的亲戚是在2.5亿年前。从那时起，青蛙进化出了许多独特的特征，然而蝾螈自从第一次在地球上行走以来一直保持相对不变，它们进化成爬行动物和哺乳动物。因此，控制蝾螈和哺乳动物胚胎发育的基因几乎相同。事实上，蝾螈是蝾螈的代表，我们已经证明它们含有多能细胞，这些细胞基本上与人类胚胎中发育的细胞相同。此外，重要的是，它们含有Nanog基因，由于不完全清楚的原因，青蛙胚胎中不存在Nanog基因。对于我们的目的，美西蝾螈胚胎是一个完美的工具，以了解多能细胞如何响应信号，告诉他们成为其他细胞类型。我们正在使用蝾螈胚胎来研究Nanog是如何被调节的。蝾螈胚胎在母体外发育，因此可以在不伤害动物的情况下收集数百个胚胎。此外，胚胎非常巨大，大约是人类胚胎大小的10，000倍，因此在实验室中解剖想要研究的细胞非常容易。我们开发的蝾螈实验系统在英国是独一无二的，我们是世界上唯一一个目前使用它来了解多能性的组织。当我们从蝾螈中分离Nanog基因时，我们发现它在控制ES细胞的行为方面与人类Nanog一样有效。但是胚胎干细胞不是胚胎，我们有独特的机会来了解Nanog在正常胚胎中的功能，在这个项目中，我们将从蝾螈胚胎中提取多能细胞，并使用含有控制正常胚胎发育的分子的溶液诱导它们成为特定类型的分化细胞。然后，我们将分析Nanog的丢失如何改变对这些信号的响应。通过识别细胞如何反应，我们将了解建立多能性的必要的第一步，这将为如何产生用于再生受损身体部位的人体组织提供线索。

项目成果

LINE-1 transcription in round spermatids is associated with accretion of 5-carboxylcytosine in their open reading frames.

• DOI: 10.1038/s42003-021-02217-8
• 发表时间: 2021-06-07
• 期刊: Communications biology
• 影响因子: 5.9
• 作者: Blythe MJ;Kocer A;Rubio-Roldan A;Giles T;Abakir A;Ialy-Radio C;Wheldon LM;Bereshchenko O;Bruscoli S;Kondrashov A;Drevet JR;Emes RD;Johnson AD;McCarrey JR;Gackowski D;Olinski R;Cocquet J;Garcia-Perez JL;Ruzov A
• 通讯作者: Ruzov A

5-Carboxylcytosine levels are elevated in human breast cancers and gliomas.

• DOI: 10.1186/s13148-015-0117-x
• 发表时间: 2015
• 期刊: Clinical epigenetics
• 影响因子: 5.7
• 作者: Eleftheriou M;Pascual AJ;Wheldon LM;Perry C;Abakir A;Arora A;Johnson AD;Auer DT;Ellis IO;Madhusudan S;Ruzov A
• 通讯作者: Ruzov A

Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos.

• DOI: 10.1242/dev.105346
• 发表时间: 2014-06
• 期刊: Development (Cambridge, England)
• 作者: Chatfield J;O'Reilly MA;Bachvarova RF;Ferjentsik Z;Redwood C;Walmsley M;Patient R;Loose M;Johnson AD
• 通讯作者: Johnson AD

Primordial germ cells: the first cell lineage or the last cells standing?

• DOI: 10.1242/dev.113993
• 发表时间: 2015-08-15
• 期刊: Development (Cambridge, England)
• 作者: Johnson AD;Alberio R
• 通讯作者: Alberio R

Detection of Modified Forms of Cytosine Using Sensitive Immunohistochemistry.

• DOI: 10.3791/54416
• 发表时间: 2016-08-16
• 期刊: Journal of visualized experiments : JoVE
• 作者: Abakir A;Wheldon L;Johnson AD;Laurent P;Ruzov A
• 通讯作者: Ruzov A