Modelling eye specification in human embryonic stem cells

在人体内，有些细胞仍然可以生长，比如皮肤细胞或血细胞，而有些细胞则不能生长，比如脑细胞。当细胞在体内自然或意外或疾病死亡时，只有当这些死亡的细胞属于仍能生长的细胞时，它们才能被新的细胞所取代。这就是为什么有些疾病至今无法治愈的原因。一种无法治疗的疾病是失明，这是由于失去了负责探测光线并将信息传递给大脑的眼细胞。如果这些细胞可以被新的细胞取代，我们就有可能治愈某些形式的失明。我们在这里提出的这项研究的最终目标是制造出能够取代视网膜中失去的细胞的细胞，视网膜是眼睛接收视觉信息并将其传递给大脑的部分。为此，我们建议使用能够转化为人体任何类型细胞的人类胚胎细胞，这种细胞被称为胚胎干细胞，并且已经可以用于实验。将胚胎干细胞转化为你需要的那种细胞的关键是用正确的分子信使来处理它们，这些分子信使告诉细胞该做什么。在我们之前的研究中，我们已经在动物模型系统中描述了许多信使，这些信使需要通知细胞它必须成为视网膜细胞。下一步是利用这些知识来指导人类胚胎干细胞的命运，以产生可用于替代因疾病而失去的视网膜细胞。

In the human body, there are cells that can still grow, like skin or blood cells, and other that cannot, like brain cells. When cells die in the body, naturally or as a consequence of accident or disease, they can be substituted by new ones only if those cells that died belong to the kind of cells that can still grow. This is the reason why some diseases cannot be cured to date. One type of disease that cannot be treated is blindness due to the loss of eye cells responsible for the detection of the light and the transmission of that information to the brain. If those cells could be substituted by new ones, we could potentially cure some forms of blindness. The investigation that we propose here has the ultimate goal of producing cells able to take the place of cells lost in the retina, the part of the eye that receives the visual information and transmits it to the brain. To do so, we propose to use human embryonic cells with the ability of transforming into any type of cell of the body, which are called embryonic stem cells and which are already available for experimentation. The key to transform embryonic stem cells into the kind of cell you need is to treat them with the right molecular messengers that tell the cells what to do. In our previous research, we have characterised in animal model systems many of the messengers that are required to inform a cell that it has to become a retinal cell. The next step is to use this knowledge to direct the fate of human embryonic stem cells to produce the retinal cells that could be used to replace those lost because of disease.