Understanding the molecular and cellular complexity of human cornea through single cell analyses

通过单细胞分析了解人类角膜的分子和细胞复杂性

基本信息

批准号：
MR/S035826/1
负责人：
Majlinda Lako
金额：
$ 58.46万
依托单位：
Newcastle University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FS035826%2F1
关键词：
Understanding molecular cellular complexity human

项目摘要

The cornea is the clear window at the front of the eye that allows light to enter and be focused on the back of the eye. To see a clear image, the cornea needs to be transparent, regular and smooth. Presence of cataracts, corneal damage and corneal diseases are the largest cause of corneal blindness which accounts for 23 million people worldwide adding a huge burden to patients and health care resources. Often the only treatment option is surgical transplantation of donor cornea, a therapeutic option that has been unchanged for more than 50 years. In Europe, over 40,000 blind people are waiting for corneal transplant every year. This shortage results in about 10 million untreated patients globally and 1.5 million new cases of blindness annually.The outer layer of the cornea (the epithelium) is continuously replaced due to normal cell shedding in response to blinking and physical and environmental damage. Limbal stem cells (LSCs) endlessly produce new epithelial cells in the cornea and prevent conjunctival epithelium (a covering of the white part of the eye) from migrating over the cornea. If these LSC are damaged or diseased, a condition called limbal stem cell deficiency (LSCD) occurs, causing discomfort and reduced vision. In patients with LSCD in one eye, LSCs can be removed from their other healthy eye and grown in a laboratory and then transplanted back into the diseased eye to restore the stem cells and their vision. Using this technique, we have been able to successfully treat 33 patients with LSCD during the last 14 years. Despite this success, we do not know yet how to identify and purify individual LSCs. Moreover, the growth of LSCs under laboratory conditions is significantly limited and they rapidly lose their ability to grow continuously. For this reason, cells used for transplantation are a mixture of LSCs and other cell types which can vary from patient to patient and from one research group to another depending on the technique used for their expansion. The number of LSCs is crucially important for the success of clinical transplantation; for example patients transplanted with laboratory expanded cultures which contain less than 3% of LSCs had a successful transplantation in only 11% of the patients, while those with more than 3% had a successful transplant in 76% of the patients. It is essential to assess the fraction of LSCs before transplantation so unsuccessful transplants can be avoided. To achieve this, we need to know more about LSCs themselves.Stem cells have also been found in other parts of the cornea, for example the middle part called stroma, and the endothelium which keeps the cornea hydrated. We don't know if stem cells in each of these layers behave the same way as each other or whether there are several types which respond in different ways to corneal damage. Great advances in technologies that allow single cells to be studied individually have enabled development of the Human Cell Atlas, which is currently focusing on tissues such as skin and blood. In this project, we propose to focus on three different regions of adult cadaveric human cornea (central, peripheral and limbal) which have been shown to differ in cell composition and density. The single cell analysis will enable us to know which genes are expressed in every cell and why and to understand how many cell types are in every region and every layer. Since our eyes develop mostly before we are born, we also propose to look at samples from aborted specimens which are donated for research with mother's consent. By understanding the complexity of cell types from development to adulthood, we will better understand how cornea is formed, how stem cells maintain corneal homeostasis and how we can increase the success of the clinical transplantations. The ultimate impact of this project will be to contribute towards safer and more efficacious treatments of a significant proportion of world blindness caused by corneal damage and disease.

角膜是眼前的透明窗户，可以使光进入并专注于眼睛的背面。要查看清晰的图像，角膜需要透明，规则和光滑。白内障，角膜损伤和角膜疾病的存在是角膜失明的最大原因，在全球范围内占2300万人，为患者和医疗保健资源增加了巨大负担。通常，唯一的治疗选择是对捐赠者角膜的手术移植，这是一种治疗选择，已有50多年的历史。在欧洲，每年有40,000多名盲人正在等待角膜移植。这种短缺导致全球约1000万未经治疗的患者，每年150万例新病例。由于响应眨眼，身体和环境损害，角膜外层（上皮）被连续替换。边缘干细胞（LSC）无休止地在角膜中产生新的上皮细胞，并防止结膜上皮（眼睛的白色部分的覆盖）迁移到角膜上。如果这些LSC损坏或患病，则会发生一种称为缘干细胞缺乏症（LSCD）的疾病，会导致不适和视力降低。在一只眼睛中LSCD的患者中，可以将LSC从另一只健康的眼睛中去除，并在实验室中生长，然后将其移回患病的眼睛以恢复干细胞及其视力。在过去的14年中，使用这种技术，我们能够成功治疗33例LSCD患者。尽管取得了成功，但我们还不知道如何识别和净化单个LSC。此外，在实验室条件下LSC的生长显着有限，它们迅速失去了持续增长的能力。因此，用于移植的细胞是LSC的混合物和其他细胞类型的混合物，这些细胞可能因患者而异，从一个研究组到另一个研究组，具体取决于其扩展的技术。 LSC的数量对于临床移植的成功至关重要。例如，只有不到3％的LSC的实验室扩展培养物移植的患者仅在11％的患者中成功移植，而3％以上的患者在76％的患者中成功地移植了。在移植之前评估LSC的比例至关重要，因此可以避免失去失败的移植。为了实现这一目标，我们需要更多地了解LSC本身。在角膜的其他部分，例如中间部分称为基质，以及保持角膜水合的内皮。我们不知道这些层中的干细胞的行为是否与彼此相同，或者是否有几种类型的方式以不同的方式响应角膜损伤。允许单独研究单个细胞的技术取得了巨大进步，已经使人类细胞地图集的发展开发，后者目前专注于皮肤和血液等组织。在这个项目中，我们建议专注于三个不同的成年尸体人角膜（中央，外围和缘缘）的区域，这些区域已被证明在细胞组成和密度方面有所不同。单细胞分析将使我们能够知道每个细胞中表达哪些基因，以及为什么并了解每个区域和每个层中有多少个细胞类型。由于我们的眼睛主要在出生之前就发展起来，因此我们还建议查看中流产的标本的样本，这些样本是通过母亲的同意而捐赠的。通过了解从发育到成年的细胞类型的复杂性，我们将更好地了解角膜的形成，干细胞如何保持角膜稳态以及如何增加临床移植的成功。该项目的最终影响是为角膜损害和疾病引起的大部分世界失明做出更安全，更有效的治疗方法。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Clinical impact of inflammation in dry eye disease: proceedings of the ODISSEY group meeting.

DOI：
10.1111/aos.13436
发表时间：
2018-03
期刊：
Acta ophthalmologica
影响因子：
3.4
作者：
Baudouin C;Irkeç M;Messmer EM;Benítez-Del-Castillo JM;Bonini S;Figueiredo FC;Geerling G;Labetoulle M;Lemp M;Rolando M;Van Setten G;Aragona P;ODISSEY European Consensus Group Members
通讯作者：
ODISSEY European Consensus Group Members

In the eye of the storm: SARS-CoV-2 infection and replication at the ocular surface?